Dictyophora rubrovalvata is an edible fungus with rich nutritional value.It contains various nutrients and bioactive components,and has immunomodulation,anti-tumor,anti-oxidation,anti-fatigue,anti-aging,anti-inflammat...Dictyophora rubrovalvata is an edible fungus with rich nutritional value.It contains various nutrients and bioactive components,and has immunomodulation,anti-tumor,anti-oxidation,anti-fatigue,anti-aging,anti-inflammation and alcoholic hepatitis-protection effects.With the continuous expansion of planting area of Dictyophora,the disease problem has become a major problem affecting the development of Dictyophora industry.In this paper,the pathogens,harmful symptoms and causes of main diseases in Dictyophora were summarized,so as to provide reference for comprehensive control of Dictyophora diseases and promote the high-quality development of Dictyophora industry.展开更多
Study Objective: The purpose of the study is to present independent laboratory testing for a novel technology in air and on surfaces. Since 2020, public health goals have focused on improving indoor air quality. This ...Study Objective: The purpose of the study is to present independent laboratory testing for a novel technology in air and on surfaces. Since 2020, public health goals have focused on improving indoor air quality. This includes protection from airborne pathogens, such as tuberculosis, RSV, SARS-CoV-2, common cold or influenza viruses, measles, and others. Engineering controls are highly effective at reducing hazardous pathogens found in indoor air and from recontamination of surfaces. This occurs from a continuous cycle of settling of small, sustained airborne pathogens, which may become dehumidified, becoming airborne again, carried by room air currents around indoor spaces, then repeating the cycle. Methods: The novel technology utilizes a catalytic process to produce safe levels of hydrogen peroxide gas that are effective in reducing pathogens in the air and on surfaces. Air testing was performed with the MS2 bacteriophage, the test organism for ASHRAE standard 241, and methicillin-Resistant Staphylococcus aureus (MRSA). Surface testing was performed with SARS-COV-2 (Coronavirus COVID-19) and H1N1 (Influenza). Typical ventilation and filtration does not effectively remove disbursed pathogens from the entire facility, due to inconsistent air circulation and surface deposits of pathogens. Results: MS2 was reduced by 99.9%;MRSA was reduced by 99.9%;SARS-CoV-2 was reduced by 99.9%;H1N1 was reduced by 99.9%. Conclusion: This novel catalytic converter reduces a variety of pathogens in the air (99%) and on surfaces (99%), by actively disinfecting with the introduction of gaseous hydrogen peroxide. This active disinfection provides a strong solution for protecting the entire facility and its occupants.展开更多
In recent years,microbial metabolomics,a new field that has attracted wide attention,provides a map of metabolic pathways and clarifies the interaction mechanism between microorganisms and hosts.Many microorganisms ar...In recent years,microbial metabolomics,a new field that has attracted wide attention,provides a map of metabolic pathways and clarifies the interaction mechanism between microorganisms and hosts.Many microorganisms are found in the human intestine,oral cavity,vagina,etc.Probiotics could maintain the good health of the host,while pathogens and an imbalance of bacterial flora lead to a series of diseases of the body and mind.Metabolomics is a science for qualitative and quantitative analysis of all metabolites in an organism or biological system,which could provide key information to understand the related metabolic pathways and associated changes.This approach analyzes the final products of cellular regulatory processes,the level of which can be regarded as the ultimate response of the biological system to genetic or environmental changes.Microbial metabolomics has been widely used in different research fields,such as microbial phenotypic classification,mutant screening,metabolic pathways,microbial metabolic engineering,fermentation engineering monitoring and optimization,microbial environmental pollution,and so on.However,there are only a few reviews on microbial metabolomics of probiotics and pathogens.This review summarizes the main methodologies,including sample preparation,identification of metabolites,data processing,and analysis.Recent applications in microbial metabolomics of probiotics and pathogens are also described.This paper first summarized the research progress and application of microbial metabolomics from two aspects:probiotics and pathogenic bacteria.Probiotics and pathogenic bacteria do not exist independently most of the time;hence,these were reviewed in the research field of coexistence of probiotics and pathogenic bacteria,which was subdivided into important microbial research fields closely related to human health,including the human gut,oral cavity,food,and nutrition-related microorganisms.Then,the main problems and trends associated with microbial metabolomics are discussed.展开更多
Because of their high efficiency, antibiotics have long been the primary treatment for infections, but the rise of drug-resistant pathogens has become a therapeutic concern. Nanoparticles, as novel biomaterials, are c...Because of their high efficiency, antibiotics have long been the primary treatment for infections, but the rise of drug-resistant pathogens has become a therapeutic concern. Nanoparticles, as novel biomaterials, are currently gaining global attention to combat them. Drug-resistant diseases may need the use of nanoparticles as a viable therapeutic option. By altering target locations and enzymes, decreasing cell permeability, inactivating enzymes, and increasing efflux by overexpressing efflux pumps, they can bypass conventional resistance mechanisms. Therefore, understanding how metal and metal oxide nanoparticles affect microorganisms that are resistant to antimicrobial drugs is the main objective of this review. Accordingly, the uses of metal and metal oxide nanoparticles in the fight against drug-resistant diseases appear promising. However, their mechanism of action, dose, and possible long-term effects require special attention and future research. Furthermore, repeated use of silver nanoparticles may cause gram-negative microorganisms to acquire resistance, necessitating additional study.展开更多
Introduction: Antimicrobial resistance is the most important health problems currently. Antibiotic prophylaxis to prevent bacterial co-infections in hospitalized COVID-19 patients, and lack of surveillance were associ...Introduction: Antimicrobial resistance is the most important health problems currently. Antibiotic prophylaxis to prevent bacterial co-infections in hospitalized COVID-19 patients, and lack of surveillance were associated with antimicrobial resistance. ESKAPE pathogens consisting of E. faecium, S. aureus, K. pneumoniae, A. baumanii, P. aeruginosa and Enterobacter spp. are associated with healthcare-associated infections. Patients and Methods: This descriptive, retrospective, longitudinal study aims to describe the resistance rates of bloodstream infection due to ESKAPE pathogens from patients admitted in Siloam Hospital Karawaci, before and during COVID-19 pandemic (January 1<sup>st</sup>, 2019 until December 31<sup>st</sup>, 2022). Out of 296 ESKAPE pathogens collected from blood samples, S. aureus was the most frequent species, followed by K. pneumoniae, A. baumannii, P. aeruginosa, Enterobacter spp., and E. faecium. Results: Resistance rates of E. faecium were alarmingly high from 2019 until 2021, but in 2022 no sample was found. Resistance rates of S. aureus and MRSA decreased from 2019 until 2021 and then increased again in 2022 while for K. pneumoniae it peaked in 2020 and reached the lowest in 2022. Resistance pattern of A. baumanii was not favorable from 2019 until 2021, but decreased dramatically in 2022. Resistance pattern of P. aeruginosa was quite variable in 2021 and 2022 while for Enterobacter spp. it was variable in 2020 to 2022. Conclusion: The COVID-19 pandemic affected the antimicrobial resistance pattern of ESKAPE pathogens in Banten province, Indonesia. Resistance rates increased as the pandemic peaked in 2020 to 2021, and decreased as the pandemic resolves in 2022.展开更多
Migratory birds travel long distance and link various pathogens.Due to habitat degradation,wintering waterfowls forage together with poultry,increasing the risk of pathogen transmission between hosts.We investigated t...Migratory birds travel long distance and link various pathogens.Due to habitat degradation,wintering waterfowls forage together with poultry,increasing the risk of pathogen transmission between hosts.We investigated the fungal communities between wintering Hooded Cranes and Domestic Geese by high-throughput sequencing,and inferred the potential gut pathogens for both hosts at different wintering stages.The fungal community compositions were significantly different between seasons and between the hosts.The negative correlation was found between fungal diversity and pathogenic diversity,with higher fungal diversity and less pathogenic diversity in early stage and less fungal diversity and higher pathogenic diversity in late stage for both hosts.The dissimilarity of pathogenic community compositions decreased from early to late stage,with the quantity of overlapping potential pathogenic OTUs increasing along wintering periods between the two hosts,demonstrating the existence of pathogen cross transmission between the two hosts.Furthermore,the transmission pathway of avian pathogens was mainly from Hooded Cranes to Domestic Geese while the transmission direction of human pathogens was primarily from Domestic Geese to wild cranes.Based on above results,we argued that pathogen cross transmission and underlying outbreak risk of disease should be closely monitored in migratory birds and domestic poultry.展开更多
Soybean root diseases are associated with numerous fungal and oomycete pathogens;however,the community dynamics and interactions of these pathogens are largely unknown.We performed 13 loop-mediated isothermal amplific...Soybean root diseases are associated with numerous fungal and oomycete pathogens;however,the community dynamics and interactions of these pathogens are largely unknown.We performed 13 loop-mediated isothermal amplification(LAMP)assays that targeted specific soybean root pathogens,and traditional isolation assays.A total of 159 samples were collected from three locations in the Huang-Huai-Hai region of China at three soybean growth stages(30,60,and 90 days after planting)in 2016.In LAMP results,we found that pathogen communities differed slightly among locations,but changed dramatically between soybean growth stages.Phytophthora sojae,Rhizoctonia solani,and Fusarium oxysporum were most frequently detected at the early stage,whereas Phomopsis longicolla,Fusarium equiseti,and Fusarium virguliforme were most common in the later stages.Most samples(86%)contained two to six pathogen species.Interestingly,the less detectable species tended to exist in the samples containing more detected species,and some pathogens preferentially co-occurred in diseased tissue,including P.sojae–R.solani–F.oxysporum and F.virguliforme–Calonectria ilicicola,implying potential interactions during infection.The LAMP detection results were confirmed by traditional isolation methods.The isolated strains exhibited different virulence to soybean,further implying a beneficial interaction among some pathogens.展开更多
Due to increasing regulations and restrictions, there is an urgent need to develop effective alternatives to chemical-dependent fumigation control of soilborne pests and pathogens. Anaerobic soil disinfestation (ASD...Due to increasing regulations and restrictions, there is an urgent need to develop effective alternatives to chemical-dependent fumigation control of soilborne pests and pathogens. Anaerobic soil disinfestation (ASD) is one such alternative showing great promise for use in the control of soilborne pathogens and pests. This method involves the application of a carbon source, irrigation to field capacity, and covering the soil with a plastic tarp. While the mechanisms of ASD are not completely understood, they appear to be a combination of changes in the soil microbial community composition, production of volatile organic compounds, and the generation of lethal anaerobic conditions. The variety of materials and options for ASD application, including carbon sources, soil temperature, and plastic tarp type, influence the efficacy of pathogen sup- pression and disease control. Currently, both dry (e.g., rice bran) and liquid (e.g., ethanol) carbon sources are commonly used, but with different results depending on environmental conditions. While solarization is not an essential component of ASD, it can enhance efficacy. Understanding the mechanisms that mediate biological changes occurring in the soil during ASD will facilitate our ability to increase ASD efficacy while enhancing its commercial viability.展开更多
Objective Lower respiratory tract infections continue to pose a significant threat to human health. It is important to accurately and rapidly detect respiratory bacteria. To compensate for the limits of current respir...Objective Lower respiratory tract infections continue to pose a significant threat to human health. It is important to accurately and rapidly detect respiratory bacteria. To compensate for the limits of current respiratory bacteria detection methods, we developed a combination of multiplex polymerase chain reaction (PCR) and capillary electrophoresis (MPCE) assay to detect thirteen bacterial pathogens responsible for lower respiratory tract infections, including Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catorrholis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Mycoplasma pneumoniae, Legionella spp., Bordetella pertussis, Mycobacterium tuberculosis complex, Corynebactefium diphthefiae, and Streptococcus pyogenes. Methods Three multiplex PCR reactions were built, and the products were analyzed by capillary electrophoresis using the high-throughput DNA analyzer. The specificity of the MPCE assay was examined and the detection limit was evaluated using DNA samples from each bacterial strain and the simulative samples of each strain. This assay was further evaluated using 152 clinical specimens and compared with real-time PCR reactions. For this assay, three nested-multiplex-PCRs were used to detect these clinical specimens. Results The detection limits of the MPCE assay for the 13 pathogens were very low and ranged from 10-7 to 10-2 ng/μL. Furthermore, analysis of the 252 clinical specimens yielded a specificity ranging from 96.5%-100.0%, and a sensitivity of 100.0% for the 13 pathogens. Conclusion This study revealed that the MPCE with high specificity and sensitivity. This assay survey of respiratory pathogens. assay is a rapid, reliable, and high-throughput method has great potential in the molecular epidemiological.展开更多
Objective:To investigate the antimicrobial activity of Clitoria ternatea(C.ternatea) against the fish pathogens viz.,Pseudomonas aeruginosa(P.aeruginosa),Escherichia coli(E.coli),Klebsiella pneumonia(K.pneumonia),Baci...Objective:To investigate the antimicrobial activity of Clitoria ternatea(C.ternatea) against the fish pathogens viz.,Pseudomonas aeruginosa(P.aeruginosa),Escherichia coli(E.coli),Klebsiella pneumonia(K.pneumonia),Bacillus subtilis(B.subtilis),Aeromonas formican(A.formicans)s, Aeromonas hydrophila(A.hydrophila) and Streptococcus agalactiae(S.agalactiae )isolated from diseased Tilapia(Oreochromis niloticus).Methods:The extracts of C.ternatea was tested against P.aeruginosa,E.coli,K.pneumonia,B.subtilis,A.formicans,A.hydrophila and S.agalactiae by the agar well diffusion method.Results:Different extracts of C.ternatea showed inhibitory effects against P.aeruginosa,E.coli,K.pneumonia,B.subtilis,A.formicans,A.hydrophila and S. agalactiae.Ethyl acetate extracts of C.ternatea showed maximum of zone of inhibition against A. formicans(18 mm),A.hydrophilia(19 mm),B.subtilis(19 mm) and P.aeruginosa(21 mm) next to that ethanol extract of C.ternatea showed A.formicans(18 mm) and E.coli(14 mm) followed by Acetone extract showed maximum zone of inhibition S.agalactiae(19 mm) and K.pneumonia(17 mm).Conclusions:The antimicrobial activities of all the four plant extracts are comparable and their potential as alternative in the treatment of infectious by these microorganisms was present in the fish.Susceptibility testing is conducted on isolates using drugs selected on the basis of their importance to human medicine and use in fish production.展开更多
Objective:To determine the prevalence and antimicrobial resistance rates of nosocomial pathogens isolated from cancer patients and hospital environments.Methods:A descriptive cross-sectional study was conducted betwee...Objective:To determine the prevalence and antimicrobial resistance rates of nosocomial pathogens isolated from cancer patients and hospital environments.Methods:A descriptive cross-sectional study was conducted between December 2010 to May 2013 at Radiation and Isotopes Centre of Khartoum,Sudan.A total of 1 503 samples(505 clinical and 998 environmental)were examined.Isolates were identified,and their antimicrobial susceptibility was determined using standard laboratory procedures.Results:Out of 505 clinical samples,nosocomial pathogens were found as 48.1%.Among hospital environment samples,bacterial contaminants were detected in 29.7%of samples.The main microorganisms recovered from cancer patients were Proteus spp.(23.5%),Escherichia coli(22.2%),Pseudomonas aeruginosa(P.aeruginosa)(21.0%)and Staphylococcus aureus(20.2%).The most frequent isolates from hospital environments were Bacillus spp.(50.0%),Staphylococcus aureus(14.2%)and P.aeruginosa(11.5%).The proportions of resistance among Gram-negative pathogens from cancer patients were high for ampicillin,cefotaxime,ceftazidime and ceftriaxone.Moderate resistance rates were recorded to ciprofloxacin,such as 51.0%for P.aeruginosa,21.7%for Klebsiella pneumoniae and 55.5%for Escherichia coli.Except Klebsiella,there were no significant differences(P0.05)of resistance rates between Gram-negative isolates from cancer patients to those from the hospital environments.The proportions of extended-spectrum b-lactamase producing isolates from cancer patients were not differ significantly(P=0.763)from those collected from the hospital environments(49.2%;91/185 vs.47%;32/68).Conclusions:The prevalence of nosocomial infection among cancer patients was high(48.1%)with the increasing of antimicrobial resistance rates.Hospital environments are potential reservoirs for nosocomial infections,which calls for intervention program to reduce environmental transmission of pathogens.展开更多
A tremendous amount of imported fresh fruits has been delivered to Shanghai markets, increasing the risk of invasion by harmful plant pathogens. Therefore, it is important to establish an effective detection and super...A tremendous amount of imported fresh fruits has been delivered to Shanghai markets, increasing the risk of invasion by harmful plant pathogens. Therefore, it is important to establish an effective detection and supervision system to survey the outbreak of the market diseases of the imported fruits during marketing. The samples were regularly surveyed in different markets to examine varieties, prices, localities, selling conditions, and diseases of the imported fruits from 2004 to 2008. The survey showed that 58 species of 30 different fruits were imported to Shanghai from 16 countries with more expensive price. The larger products were bananas, grapes, apples, and oranges. During the investigation, we found that the imported fruits frequently brought about the relatively serious market diseases. On the basis of morphology and the nuclear internal transcribed spacer (ITS) of ribosomal DNA (rDNA) analysis, 151 isolates of 15 fungi genera, which shown to be pathogenic after the inoculation assay, were finally identified. Among the identified fungi, Alternaria was the most frequent one with the highest detection rate (47.68%), followed by Penicillium (14.57%) and Fusarium (11.92%), respectively. Additionally, Pestalotiopsis microspora (detected in grapes Red-Globe coming from the USA) and Botrytis sp. (detected in black-plums coming from the USA) were first reported in China market. The present study summarized the selling situation of the imported fruits in Shanghai markets and constructed a library of the pathogens detected in the imported fruits during the selling period. The results obtained are useful to offer technical parameters for Chinese quarantine in order to prevent an invasion of the foreign harmful micro-organisms.展开更多
Raw poultry and poultry products are a significant source of zoonotic bacterial pathogen transmission;thus the sensitive detection of major zoonotic pathogens (Salmonella spp., Campylobacter jejuni, and Listeria monoc...Raw poultry and poultry products are a significant source of zoonotic bacterial pathogen transmission;thus the sensitive detection of major zoonotic pathogens (Salmonella spp., Campylobacter jejuni, and Listeria monocytogenes) is a vital food safety issue. Recently, third generation PCR technology, known as droplet digital PCR (ddPCR) has been developed to be more accurate and sensitive to detect genetic targets than current quantification methods, but this technology has not been tested within an industrial setting. There is an on-going study within our laboratory is investigating the effects of sampling times and sampling methods on the cultural and molecular (via qPCR) quantification of dominant zoonotic pathogens within a poultry processing facility. This presents a unique opportunity to compare the quantification resulted from this emerging, third generation technology to traditional quantification methods currently employed by the poultry industry. The results show that ddPCR detected pathogen-specific genes from more pathogen:sampling time combinations than either the qPCR or culturing methods from the final scalder and chiller tanks at three stages of processing (Start, Mid, and End). In fact, both ddPCR and qPCR substantially outperformed culture methods commonly used in poultry processing food safety-related studies, with Salmonella recovered only from the Mid and End sampling times from the scalder tank. While neither C. jejuni nor L. monocytogenes were recovered culturally, ddPCR was able to detect their respective genes commonly throughout the processing day in both the scalder and chiller water samples. Additionally, the use of unfiltered processing water provided significantly greater detection of bacterial and pathogen-specific gene abundances than did an analysis of larger volumes of filtered water. Considering the ddPCR-derived concentrations of the bacterial pathogens were consistent with what was previously found culturally in commercial poultry processing operations, ddPCR represented a significant advancement in poultry processing zoonotic pathogen quantification.展开更多
Mitogen-activated protein kinase(MAPK)cascades play important roles in plant immunity.Previously,we reported that the potato StMKK1 protein negatively regulates Nicotiana benthamiana resistance to Phytophthora infesta...Mitogen-activated protein kinase(MAPK)cascades play important roles in plant immunity.Previously,we reported that the potato StMKK1 protein negatively regulates Nicotiana benthamiana resistance to Phytophthora infestans.However,the functions of StMKK1 in potato immunity are unknown.To investigate the roles of StMKK1 in potato resistance to different pathogens,such as the potato late-blight pathogen P.infestans,the bacterial wilt pathogen Ralstonia solanacearum,and the gray-mold fungal pathogen Botrytis cinerea,we generated StMKK1 transgenic lines and investigated the response of potato transformants to destructive oomycete,bacterial,and fungal pathogens.The results showed that overexpression and silencing of StMKK1 do not alter plant growth and development.Interestingly,we found that StMKK1 negatively regulated potato resistance to the hemibiotrophic/biotrophic pathogens P.infestans and R.solanacearum,while it positively regulated potato resistance to the necrotrophic pathogen B.cinerea.Further investigation showed that overexpression of StMKK1 suppressed potato pathogen-associated molecular pattern(PAMP)-triggered immunity(PTI)and salicylic acid(SA)-related responses,while silencing of StMKK1 enhanced PTI and SA-related immune responses.Taken together,our results showed that StMKK1 plays dual roles in potato defense against different plant pathogens via negative regulation of PTI and SA-related signaling pathways.展开更多
AIM: To investigate the benefits of probiotics treatment in septic rats. METHODS: The septic rats were induced by cecal ligation and puncture. The animals of control, septic model and probiotics treated groups were tr...AIM: To investigate the benefits of probiotics treatment in septic rats. METHODS: The septic rats were induced by cecal ligation and puncture. The animals of control, septic model and probiotics treated groups were treated with vehicle and mixed probiotics, respectively. The mixture of probiotics included Bifidobacterium longum , Lacto-bacillus bulgaricus and Streptococcus thermophilus . We observed the survival of septic rats using different amounts of mixed probiotics. We also detected the bacterial population in ascites and blood of experimental sepsis using cultivation and real-time polymerase chain reaction. The severity of mucosal inflammation in colonic tissues was determined. RESULTS: Probiotics treatment improved survival of the rats significantly and this effect was dose dependent. The survival rate was 30% for vehicle-treated septic model group. However, 1 and 1/4 doses of probiotics treatment increased survival rate significantly comparedwith septic model group (80% and 55% vs 30%, P < 0.05). The total viable counts of bacteria in ascites decreased significantly in probiotics treated group compared with septic model group (5.20 ± 0.57 vs 9.81 ± 0.67, P < 0.05). The total positive rate of hemoculture decreased significantly in probiotics treated group compared with septic model group (33.3% vs 100.0%, P < 0.05). The population of Escherichia coli and Staphy-lococcus aureus in ascites of probiotics treated group were decreased significantly compared with that of septic model group (3.93 ± 0.73vs 8.80 ± 0.83,P < 0.05; 2.80 ± 1.04 vs 5.39 ± 1.21, P < 0.05). With probiotics treatment, there was a decrease in the scores of inflammatory cell infiltration into the intestinal mucosa in septic animals (1.50 ± 0.25vs 2.88 ± 0.14,P < 0.01). CONCLUSION: Escherichia coli and Staphylococcus aureus may be primary pathogens in septic rats. Probiotics improve survival of septic rats by suppressing these conditioned pathogens.展开更多
This pathogenic study shows that the viral diseases of Chinese prawns (Penaeus chinensis. O’sbeck)is due to three kinds of viruses: epithelium envelope baculovirus of Penaeus chinensis (EEBV-PC, de-tected by the auth...This pathogenic study shows that the viral diseases of Chinese prawns (Penaeus chinensis. O’sbeck)is due to three kinds of viruses: epithelium envelope baculovirus of Penaeus chinensis (EEBV-PC, de-tected by the authors in 1993), infections hypodermal and hematopoietic necrosis virus, andhepatopancreatic parvo-like virus, and that the first two viruses seem to be the main pathogens of theepidemic in the northern regions in 1993.展开更多
Apple replant disease(ARD)is a major limitation to the establishment of economically viable orchards on replant sites due to the buildup and long-term survival of pathogen inoculum.Several soilborne necrotrophic fungi...Apple replant disease(ARD)is a major limitation to the establishment of economically viable orchards on replant sites due to the buildup and long-term survival of pathogen inoculum.Several soilborne necrotrophic fungi and oomycetes are primarily responsible for ARD,and symptoms range from serious inhibition of growth to the death of young trees.Chemical fumigation has been the primary method used for control of ARD,and manipulating soil microbial ecology to reduce pathogen density and aggressiveness is being investigated.To date,innate resistance of apple rootstocks as a means to control this disease has not been carefully explored,partly due to the complex etiology and the difficulty in phenotyping the disease resistance.Molecular defense responses of plant roots to soilborne necrotrophic pathogens are largely elusive,although considerable progress has been achieved using foliar disease systems.Plant defense responses to necrotrophic pathogens consist of several interacting modules and operate as a network.Upon pathogen detection by plants,cellular signals such as the oscillation of Ca^(2+)concentration,reactive oxygen species(ROS)burst and protein kinase activity,lead to plant hormone biosynthesis and signaling.Jasmonic acid(JA)and ethylene(ET)are known to be fundamental to the induction and regulation of defense mechanisms toward invading necrotrophic pathogens.Complicated hormone crosstalk modulates the fine-tuning of transcriptional reprogramming and metabolic redirection,resulting in production of antimicrobial metabolites,enzyme inhibitors and cell wall refortification to restrict further pathogenesis.Transcriptome profiling of apple roots in response to inoculation with Pythium ultimum demonstrated that there is a high degree of conservation regarding the molecular framework of defense responses compared with those observed with foliar tissues.It is conceivable that the timing and intensity of genotype-specific defense responses may lead to different outcomes between rootstocks in response to invasion by necrotrophic pathogens.Elucidation of host defense mechanisms is critical in developing molecular tools for genomics-assisted breeding of resistant apple rootstocks.Due to their perennial nature,use of resistant rootstocks as a component for disease management might offer a durable and cost-effective benefit to tree performance than the standard practice of soil fumigation for control of ARD.展开更多
The study was conducted to make clear the activity of azoxystrobin to 4 plant pathogens and the synergistic effects of salicylhydroxamic acid (SHAM), which acted on the alternative oxidase. It was also conducted to ...The study was conducted to make clear the activity of azoxystrobin to 4 plant pathogens and the synergistic effects of salicylhydroxamic acid (SHAM), which acted on the alternative oxidase. It was also conducted to be aware of the mechanism of azoxystrobin in inhibition on mycelial respiration and the influence of SHAM. The activity test of azoxystrobin and SHAM was carried out with a mycelial linear growth test and spore germination test. Other related biological properties were also observed. Inhibition of azoxystrobin and SHAM on 4 pathogens was determined by using SP-II oxygraph system. Azoxystrobin inhibited mycelial growth in Colletotrichum capsici, Botrytis cinerea, Rhizoctonia solani, and Magnaporthe grisea, respectively; it also inhibited conidia germination, and conidia production in C. capsici, B. cinerea M. grisea, and sclerotia formation in R. solani. Moreover, it created stayed pigment biosynthesis in C. capsici and M. grisea somehow. Salicylhydroxamic acid enhanced inhibition by azoxystrobin. An oxygen consuming test of the mycelia showed that azoxystrobin inhibited all the 4 fungi's respiration in the early stages. With the concentration rising up, the effectiveness increased. However, as time went on, the respiration of the mycelia treated with fungicides recovered and SHAM could not inhibit the oxygen consuming. This reaction between the mycelia and the fungicides appeared not to initiate alternative respiration but rather the other mechanism created a lack of efficacy.展开更多
In dairy and food industries lactic acid bacteria (LAB) have been used in form of starter culture that plays vital role in fermentation; as flavouring and texturizing or as preservative agents. There is increasing e...In dairy and food industries lactic acid bacteria (LAB) have been used in form of starter culture that plays vital role in fermentation; as flavouring and texturizing or as preservative agents. There is increasing evidence that lactobacilli which inhabit the gastrointestinal tract develop antimicrobial activities and participate in the host's defence system[1]. During fermentation, most of the LAB produces a number of different compounds like organic acids, hydrogen peroxide, diacetyl, acetaldehyde, carbon dioxide, polysaccharides, and proteinaceous compounds called bacteriocins or bacteriocinogenic peptides.展开更多
Silver nanoparticles have mainly been studied for their antimicrobial potential against bacteria, but have also proven to be active against several types of viruses, even against pebrine as well. Methods: Petri dishes...Silver nanoparticles have mainly been studied for their antimicrobial potential against bacteria, but have also proven to be active against several types of viruses, even against pebrine as well. Methods: Petri dishes and transmission electronic microscope were applied to observe silver nanoparticles against bacteria strains and nuclear polyhedral viruses (NPV) and cytoplasmic polyhedral viruses (CPV). For biological test, 108 CFU/mL NPV with strong pathogenicity, and the NPV samples treated with 1:100 ratio of “Sumerian Silver” for 8 hrs were sprayed on the mulberry leaves, respectively, for silkworm rearing. Conclusion: Silver nanoparticle solution showed a strong bactericidal effect against both G+ and G﹣bacterial pathogenic strains from Bombyx mori and mulberry. Under transmission electronic microscope (TEM), Bacillus sp. Samples showed light particles in the cells when treated with silver nanoparticles, in contrast, untreated samples showed homogeneity contents. Further, NPV particles showed no significant differences between treated and untreated samples, but CPV showed strong effects that almost all CPV were collapsed. For biological test, “Sumerian Silver” treated NPV showed no diseased silkworm but nearly all silkworms were dead with no treatment. It seems like that silver nanoparticles were proved to be more effective against CPV than that of NPV. The significant differences between two antivirus or virucidal mechanism should be greatly aroused the scientific interest.展开更多
基金Supported by Guiyang Science and Technology Planning Project (ZKHT[2020]3-13).
文摘Dictyophora rubrovalvata is an edible fungus with rich nutritional value.It contains various nutrients and bioactive components,and has immunomodulation,anti-tumor,anti-oxidation,anti-fatigue,anti-aging,anti-inflammation and alcoholic hepatitis-protection effects.With the continuous expansion of planting area of Dictyophora,the disease problem has become a major problem affecting the development of Dictyophora industry.In this paper,the pathogens,harmful symptoms and causes of main diseases in Dictyophora were summarized,so as to provide reference for comprehensive control of Dictyophora diseases and promote the high-quality development of Dictyophora industry.
文摘Study Objective: The purpose of the study is to present independent laboratory testing for a novel technology in air and on surfaces. Since 2020, public health goals have focused on improving indoor air quality. This includes protection from airborne pathogens, such as tuberculosis, RSV, SARS-CoV-2, common cold or influenza viruses, measles, and others. Engineering controls are highly effective at reducing hazardous pathogens found in indoor air and from recontamination of surfaces. This occurs from a continuous cycle of settling of small, sustained airborne pathogens, which may become dehumidified, becoming airborne again, carried by room air currents around indoor spaces, then repeating the cycle. Methods: The novel technology utilizes a catalytic process to produce safe levels of hydrogen peroxide gas that are effective in reducing pathogens in the air and on surfaces. Air testing was performed with the MS2 bacteriophage, the test organism for ASHRAE standard 241, and methicillin-Resistant Staphylococcus aureus (MRSA). Surface testing was performed with SARS-COV-2 (Coronavirus COVID-19) and H1N1 (Influenza). Typical ventilation and filtration does not effectively remove disbursed pathogens from the entire facility, due to inconsistent air circulation and surface deposits of pathogens. Results: MS2 was reduced by 99.9%;MRSA was reduced by 99.9%;SARS-CoV-2 was reduced by 99.9%;H1N1 was reduced by 99.9%. Conclusion: This novel catalytic converter reduces a variety of pathogens in the air (99%) and on surfaces (99%), by actively disinfecting with the introduction of gaseous hydrogen peroxide. This active disinfection provides a strong solution for protecting the entire facility and its occupants.
基金This work was supported by the Science Foundation of Heilongjiang Administration of Traditional Chinese Medicine(No.ZHY18-021).
文摘In recent years,microbial metabolomics,a new field that has attracted wide attention,provides a map of metabolic pathways and clarifies the interaction mechanism between microorganisms and hosts.Many microorganisms are found in the human intestine,oral cavity,vagina,etc.Probiotics could maintain the good health of the host,while pathogens and an imbalance of bacterial flora lead to a series of diseases of the body and mind.Metabolomics is a science for qualitative and quantitative analysis of all metabolites in an organism or biological system,which could provide key information to understand the related metabolic pathways and associated changes.This approach analyzes the final products of cellular regulatory processes,the level of which can be regarded as the ultimate response of the biological system to genetic or environmental changes.Microbial metabolomics has been widely used in different research fields,such as microbial phenotypic classification,mutant screening,metabolic pathways,microbial metabolic engineering,fermentation engineering monitoring and optimization,microbial environmental pollution,and so on.However,there are only a few reviews on microbial metabolomics of probiotics and pathogens.This review summarizes the main methodologies,including sample preparation,identification of metabolites,data processing,and analysis.Recent applications in microbial metabolomics of probiotics and pathogens are also described.This paper first summarized the research progress and application of microbial metabolomics from two aspects:probiotics and pathogenic bacteria.Probiotics and pathogenic bacteria do not exist independently most of the time;hence,these were reviewed in the research field of coexistence of probiotics and pathogenic bacteria,which was subdivided into important microbial research fields closely related to human health,including the human gut,oral cavity,food,and nutrition-related microorganisms.Then,the main problems and trends associated with microbial metabolomics are discussed.
文摘Because of their high efficiency, antibiotics have long been the primary treatment for infections, but the rise of drug-resistant pathogens has become a therapeutic concern. Nanoparticles, as novel biomaterials, are currently gaining global attention to combat them. Drug-resistant diseases may need the use of nanoparticles as a viable therapeutic option. By altering target locations and enzymes, decreasing cell permeability, inactivating enzymes, and increasing efflux by overexpressing efflux pumps, they can bypass conventional resistance mechanisms. Therefore, understanding how metal and metal oxide nanoparticles affect microorganisms that are resistant to antimicrobial drugs is the main objective of this review. Accordingly, the uses of metal and metal oxide nanoparticles in the fight against drug-resistant diseases appear promising. However, their mechanism of action, dose, and possible long-term effects require special attention and future research. Furthermore, repeated use of silver nanoparticles may cause gram-negative microorganisms to acquire resistance, necessitating additional study.
文摘Introduction: Antimicrobial resistance is the most important health problems currently. Antibiotic prophylaxis to prevent bacterial co-infections in hospitalized COVID-19 patients, and lack of surveillance were associated with antimicrobial resistance. ESKAPE pathogens consisting of E. faecium, S. aureus, K. pneumoniae, A. baumanii, P. aeruginosa and Enterobacter spp. are associated with healthcare-associated infections. Patients and Methods: This descriptive, retrospective, longitudinal study aims to describe the resistance rates of bloodstream infection due to ESKAPE pathogens from patients admitted in Siloam Hospital Karawaci, before and during COVID-19 pandemic (January 1<sup>st</sup>, 2019 until December 31<sup>st</sup>, 2022). Out of 296 ESKAPE pathogens collected from blood samples, S. aureus was the most frequent species, followed by K. pneumoniae, A. baumannii, P. aeruginosa, Enterobacter spp., and E. faecium. Results: Resistance rates of E. faecium were alarmingly high from 2019 until 2021, but in 2022 no sample was found. Resistance rates of S. aureus and MRSA decreased from 2019 until 2021 and then increased again in 2022 while for K. pneumoniae it peaked in 2020 and reached the lowest in 2022. Resistance pattern of A. baumanii was not favorable from 2019 until 2021, but decreased dramatically in 2022. Resistance pattern of P. aeruginosa was quite variable in 2021 and 2022 while for Enterobacter spp. it was variable in 2020 to 2022. Conclusion: The COVID-19 pandemic affected the antimicrobial resistance pattern of ESKAPE pathogens in Banten province, Indonesia. Resistance rates increased as the pandemic peaked in 2020 to 2021, and decreased as the pandemic resolves in 2022.
基金supported by the“National Natural Science Foundation of China”(Grant No.31801989)the Outstanding Youth Research Project of Anhui Province for Xingjia Xiang(2022AH030015).
文摘Migratory birds travel long distance and link various pathogens.Due to habitat degradation,wintering waterfowls forage together with poultry,increasing the risk of pathogen transmission between hosts.We investigated the fungal communities between wintering Hooded Cranes and Domestic Geese by high-throughput sequencing,and inferred the potential gut pathogens for both hosts at different wintering stages.The fungal community compositions were significantly different between seasons and between the hosts.The negative correlation was found between fungal diversity and pathogenic diversity,with higher fungal diversity and less pathogenic diversity in early stage and less fungal diversity and higher pathogenic diversity in late stage for both hosts.The dissimilarity of pathogenic community compositions decreased from early to late stage,with the quantity of overlapping potential pathogenic OTUs increasing along wintering periods between the two hosts,demonstrating the existence of pathogen cross transmission between the two hosts.Furthermore,the transmission pathway of avian pathogens was mainly from Hooded Cranes to Domestic Geese while the transmission direction of human pathogens was primarily from Domestic Geese to wild cranes.Based on above results,we argued that pathogen cross transmission and underlying outbreak risk of disease should be closely monitored in migratory birds and domestic poultry.
基金supported by the grants to Prof.Zheng Xiaobo and Prof.Wang Yuanchao from the National Key R&D Program of China(2018YFD0201000)the earmarked fund for China Agriculture Research System(CARS-004-PS14)+1 种基金the National Natural Science Foundation of China(31721004)by the grant to Associate Prof.Ye Wenwu from the National Natural Science Foundation of China(31772140)。
文摘Soybean root diseases are associated with numerous fungal and oomycete pathogens;however,the community dynamics and interactions of these pathogens are largely unknown.We performed 13 loop-mediated isothermal amplification(LAMP)assays that targeted specific soybean root pathogens,and traditional isolation assays.A total of 159 samples were collected from three locations in the Huang-Huai-Hai region of China at three soybean growth stages(30,60,and 90 days after planting)in 2016.In LAMP results,we found that pathogen communities differed slightly among locations,but changed dramatically between soybean growth stages.Phytophthora sojae,Rhizoctonia solani,and Fusarium oxysporum were most frequently detected at the early stage,whereas Phomopsis longicolla,Fusarium equiseti,and Fusarium virguliforme were most common in the later stages.Most samples(86%)contained two to six pathogen species.Interestingly,the less detectable species tended to exist in the samples containing more detected species,and some pathogens preferentially co-occurred in diseased tissue,including P.sojae–R.solani–F.oxysporum and F.virguliforme–Calonectria ilicicola,implying potential interactions during infection.The LAMP detection results were confirmed by traditional isolation methods.The isolated strains exhibited different virulence to soybean,further implying a beneficial interaction among some pathogens.
基金the California Department of Food and Agriculture Fruit Tree, Nut Tree, and Grapevine Improvement Advisory Board, USA
文摘Due to increasing regulations and restrictions, there is an urgent need to develop effective alternatives to chemical-dependent fumigation control of soilborne pests and pathogens. Anaerobic soil disinfestation (ASD) is one such alternative showing great promise for use in the control of soilborne pathogens and pests. This method involves the application of a carbon source, irrigation to field capacity, and covering the soil with a plastic tarp. While the mechanisms of ASD are not completely understood, they appear to be a combination of changes in the soil microbial community composition, production of volatile organic compounds, and the generation of lethal anaerobic conditions. The variety of materials and options for ASD application, including carbon sources, soil temperature, and plastic tarp type, influence the efficacy of pathogen sup- pression and disease control. Currently, both dry (e.g., rice bran) and liquid (e.g., ethanol) carbon sources are commonly used, but with different results depending on environmental conditions. While solarization is not an essential component of ASD, it can enhance efficacy. Understanding the mechanisms that mediate biological changes occurring in the soil during ASD will facilitate our ability to increase ASD efficacy while enhancing its commercial viability.
基金supported by grants from the Priority Project on Infectious Disease Control and Prevention(2012ZX10004215,2013ZX10004610)from Ministry of Health,China,and the Science Foundation for the State Key Laboratory for Infectious Disease Prevention and Control from China(Grant No.2015SKLID508)the National Natural Science Foundation of China(Grant No.81671985)and(Grant No.81170009)
文摘Objective Lower respiratory tract infections continue to pose a significant threat to human health. It is important to accurately and rapidly detect respiratory bacteria. To compensate for the limits of current respiratory bacteria detection methods, we developed a combination of multiplex polymerase chain reaction (PCR) and capillary electrophoresis (MPCE) assay to detect thirteen bacterial pathogens responsible for lower respiratory tract infections, including Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catorrholis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Mycoplasma pneumoniae, Legionella spp., Bordetella pertussis, Mycobacterium tuberculosis complex, Corynebactefium diphthefiae, and Streptococcus pyogenes. Methods Three multiplex PCR reactions were built, and the products were analyzed by capillary electrophoresis using the high-throughput DNA analyzer. The specificity of the MPCE assay was examined and the detection limit was evaluated using DNA samples from each bacterial strain and the simulative samples of each strain. This assay was further evaluated using 152 clinical specimens and compared with real-time PCR reactions. For this assay, three nested-multiplex-PCRs were used to detect these clinical specimens. Results The detection limits of the MPCE assay for the 13 pathogens were very low and ranged from 10-7 to 10-2 ng/μL. Furthermore, analysis of the 252 clinical specimens yielded a specificity ranging from 96.5%-100.0%, and a sensitivity of 100.0% for the 13 pathogens. Conclusion This study revealed that the MPCE with high specificity and sensitivity. This assay survey of respiratory pathogens. assay is a rapid, reliable, and high-throughput method has great potential in the molecular epidemiological.
文摘Objective:To investigate the antimicrobial activity of Clitoria ternatea(C.ternatea) against the fish pathogens viz.,Pseudomonas aeruginosa(P.aeruginosa),Escherichia coli(E.coli),Klebsiella pneumonia(K.pneumonia),Bacillus subtilis(B.subtilis),Aeromonas formican(A.formicans)s, Aeromonas hydrophila(A.hydrophila) and Streptococcus agalactiae(S.agalactiae )isolated from diseased Tilapia(Oreochromis niloticus).Methods:The extracts of C.ternatea was tested against P.aeruginosa,E.coli,K.pneumonia,B.subtilis,A.formicans,A.hydrophila and S.agalactiae by the agar well diffusion method.Results:Different extracts of C.ternatea showed inhibitory effects against P.aeruginosa,E.coli,K.pneumonia,B.subtilis,A.formicans,A.hydrophila and S. agalactiae.Ethyl acetate extracts of C.ternatea showed maximum of zone of inhibition against A. formicans(18 mm),A.hydrophilia(19 mm),B.subtilis(19 mm) and P.aeruginosa(21 mm) next to that ethanol extract of C.ternatea showed A.formicans(18 mm) and E.coli(14 mm) followed by Acetone extract showed maximum zone of inhibition S.agalactiae(19 mm) and K.pneumonia(17 mm).Conclusions:The antimicrobial activities of all the four plant extracts are comparable and their potential as alternative in the treatment of infectious by these microorganisms was present in the fish.Susceptibility testing is conducted on isolates using drugs selected on the basis of their importance to human medicine and use in fish production.
基金project was approved by the research committee of Faculty of Medical Laboratory Sciences,University of Khartoum as Ph D degree requirements to Aymen Nurain
文摘Objective:To determine the prevalence and antimicrobial resistance rates of nosocomial pathogens isolated from cancer patients and hospital environments.Methods:A descriptive cross-sectional study was conducted between December 2010 to May 2013 at Radiation and Isotopes Centre of Khartoum,Sudan.A total of 1 503 samples(505 clinical and 998 environmental)were examined.Isolates were identified,and their antimicrobial susceptibility was determined using standard laboratory procedures.Results:Out of 505 clinical samples,nosocomial pathogens were found as 48.1%.Among hospital environment samples,bacterial contaminants were detected in 29.7%of samples.The main microorganisms recovered from cancer patients were Proteus spp.(23.5%),Escherichia coli(22.2%),Pseudomonas aeruginosa(P.aeruginosa)(21.0%)and Staphylococcus aureus(20.2%).The most frequent isolates from hospital environments were Bacillus spp.(50.0%),Staphylococcus aureus(14.2%)and P.aeruginosa(11.5%).The proportions of resistance among Gram-negative pathogens from cancer patients were high for ampicillin,cefotaxime,ceftazidime and ceftriaxone.Moderate resistance rates were recorded to ciprofloxacin,such as 51.0%for P.aeruginosa,21.7%for Klebsiella pneumoniae and 55.5%for Escherichia coli.Except Klebsiella,there were no significant differences(P0.05)of resistance rates between Gram-negative isolates from cancer patients to those from the hospital environments.The proportions of extended-spectrum b-lactamase producing isolates from cancer patients were not differ significantly(P=0.763)from those collected from the hospital environments(49.2%;91/185 vs.47%;32/68).Conclusions:The prevalence of nosocomial infection among cancer patients was high(48.1%)with the increasing of antimicrobial resistance rates.Hospital environments are potential reservoirs for nosocomial infections,which calls for intervention program to reduce environmental transmission of pathogens.
基金supported by the National Natural Sci-ence Foundation of China (30771505)the projects of Shanghai Science and Technology Commission,China (07DZ12043)
文摘A tremendous amount of imported fresh fruits has been delivered to Shanghai markets, increasing the risk of invasion by harmful plant pathogens. Therefore, it is important to establish an effective detection and supervision system to survey the outbreak of the market diseases of the imported fruits during marketing. The samples were regularly surveyed in different markets to examine varieties, prices, localities, selling conditions, and diseases of the imported fruits from 2004 to 2008. The survey showed that 58 species of 30 different fruits were imported to Shanghai from 16 countries with more expensive price. The larger products were bananas, grapes, apples, and oranges. During the investigation, we found that the imported fruits frequently brought about the relatively serious market diseases. On the basis of morphology and the nuclear internal transcribed spacer (ITS) of ribosomal DNA (rDNA) analysis, 151 isolates of 15 fungi genera, which shown to be pathogenic after the inoculation assay, were finally identified. Among the identified fungi, Alternaria was the most frequent one with the highest detection rate (47.68%), followed by Penicillium (14.57%) and Fusarium (11.92%), respectively. Additionally, Pestalotiopsis microspora (detected in grapes Red-Globe coming from the USA) and Botrytis sp. (detected in black-plums coming from the USA) were first reported in China market. The present study summarized the selling situation of the imported fruits in Shanghai markets and constructed a library of the pathogens detected in the imported fruits during the selling period. The results obtained are useful to offer technical parameters for Chinese quarantine in order to prevent an invasion of the foreign harmful micro-organisms.
文摘Raw poultry and poultry products are a significant source of zoonotic bacterial pathogen transmission;thus the sensitive detection of major zoonotic pathogens (Salmonella spp., Campylobacter jejuni, and Listeria monocytogenes) is a vital food safety issue. Recently, third generation PCR technology, known as droplet digital PCR (ddPCR) has been developed to be more accurate and sensitive to detect genetic targets than current quantification methods, but this technology has not been tested within an industrial setting. There is an on-going study within our laboratory is investigating the effects of sampling times and sampling methods on the cultural and molecular (via qPCR) quantification of dominant zoonotic pathogens within a poultry processing facility. This presents a unique opportunity to compare the quantification resulted from this emerging, third generation technology to traditional quantification methods currently employed by the poultry industry. The results show that ddPCR detected pathogen-specific genes from more pathogen:sampling time combinations than either the qPCR or culturing methods from the final scalder and chiller tanks at three stages of processing (Start, Mid, and End). In fact, both ddPCR and qPCR substantially outperformed culture methods commonly used in poultry processing food safety-related studies, with Salmonella recovered only from the Mid and End sampling times from the scalder tank. While neither C. jejuni nor L. monocytogenes were recovered culturally, ddPCR was able to detect their respective genes commonly throughout the processing day in both the scalder and chiller water samples. Additionally, the use of unfiltered processing water provided significantly greater detection of bacterial and pathogen-specific gene abundances than did an analysis of larger volumes of filtered water. Considering the ddPCR-derived concentrations of the bacterial pathogens were consistent with what was previously found culturally in commercial poultry processing operations, ddPCR represented a significant advancement in poultry processing zoonotic pathogen quantification.
基金This work was financed by the National Natural Science Foundation of China(31701770,32072401)the China Postdoctoral Science Foundation(2019T120956 and 2016M600818)+1 种基金the Postdoctoral Science Foundation of Shaanxi Province(2017BSHYDZZ63)the Northwest A&F University Scientific Research Fund for Advanced Talents(2452018028 and 2452017069).
文摘Mitogen-activated protein kinase(MAPK)cascades play important roles in plant immunity.Previously,we reported that the potato StMKK1 protein negatively regulates Nicotiana benthamiana resistance to Phytophthora infestans.However,the functions of StMKK1 in potato immunity are unknown.To investigate the roles of StMKK1 in potato resistance to different pathogens,such as the potato late-blight pathogen P.infestans,the bacterial wilt pathogen Ralstonia solanacearum,and the gray-mold fungal pathogen Botrytis cinerea,we generated StMKK1 transgenic lines and investigated the response of potato transformants to destructive oomycete,bacterial,and fungal pathogens.The results showed that overexpression and silencing of StMKK1 do not alter plant growth and development.Interestingly,we found that StMKK1 negatively regulated potato resistance to the hemibiotrophic/biotrophic pathogens P.infestans and R.solanacearum,while it positively regulated potato resistance to the necrotrophic pathogen B.cinerea.Further investigation showed that overexpression of StMKK1 suppressed potato pathogen-associated molecular pattern(PAMP)-triggered immunity(PTI)and salicylic acid(SA)-related responses,while silencing of StMKK1 enhanced PTI and SA-related immune responses.Taken together,our results showed that StMKK1 plays dual roles in potato defense against different plant pathogens via negative regulation of PTI and SA-related signaling pathways.
文摘AIM: To investigate the benefits of probiotics treatment in septic rats. METHODS: The septic rats were induced by cecal ligation and puncture. The animals of control, septic model and probiotics treated groups were treated with vehicle and mixed probiotics, respectively. The mixture of probiotics included Bifidobacterium longum , Lacto-bacillus bulgaricus and Streptococcus thermophilus . We observed the survival of septic rats using different amounts of mixed probiotics. We also detected the bacterial population in ascites and blood of experimental sepsis using cultivation and real-time polymerase chain reaction. The severity of mucosal inflammation in colonic tissues was determined. RESULTS: Probiotics treatment improved survival of the rats significantly and this effect was dose dependent. The survival rate was 30% for vehicle-treated septic model group. However, 1 and 1/4 doses of probiotics treatment increased survival rate significantly comparedwith septic model group (80% and 55% vs 30%, P < 0.05). The total viable counts of bacteria in ascites decreased significantly in probiotics treated group compared with septic model group (5.20 ± 0.57 vs 9.81 ± 0.67, P < 0.05). The total positive rate of hemoculture decreased significantly in probiotics treated group compared with septic model group (33.3% vs 100.0%, P < 0.05). The population of Escherichia coli and Staphy-lococcus aureus in ascites of probiotics treated group were decreased significantly compared with that of septic model group (3.93 ± 0.73vs 8.80 ± 0.83,P < 0.05; 2.80 ± 1.04 vs 5.39 ± 1.21, P < 0.05). With probiotics treatment, there was a decrease in the scores of inflammatory cell infiltration into the intestinal mucosa in septic animals (1.50 ± 0.25vs 2.88 ± 0.14,P < 0.01). CONCLUSION: Escherichia coli and Staphylococcus aureus may be primary pathogens in septic rats. Probiotics improve survival of septic rats by suppressing these conditioned pathogens.
文摘This pathogenic study shows that the viral diseases of Chinese prawns (Penaeus chinensis. O’sbeck)is due to three kinds of viruses: epithelium envelope baculovirus of Penaeus chinensis (EEBV-PC, de-tected by the authors in 1993), infections hypodermal and hematopoietic necrosis virus, andhepatopancreatic parvo-like virus, and that the first two viruses seem to be the main pathogens of theepidemic in the northern regions in 1993.
文摘Apple replant disease(ARD)is a major limitation to the establishment of economically viable orchards on replant sites due to the buildup and long-term survival of pathogen inoculum.Several soilborne necrotrophic fungi and oomycetes are primarily responsible for ARD,and symptoms range from serious inhibition of growth to the death of young trees.Chemical fumigation has been the primary method used for control of ARD,and manipulating soil microbial ecology to reduce pathogen density and aggressiveness is being investigated.To date,innate resistance of apple rootstocks as a means to control this disease has not been carefully explored,partly due to the complex etiology and the difficulty in phenotyping the disease resistance.Molecular defense responses of plant roots to soilborne necrotrophic pathogens are largely elusive,although considerable progress has been achieved using foliar disease systems.Plant defense responses to necrotrophic pathogens consist of several interacting modules and operate as a network.Upon pathogen detection by plants,cellular signals such as the oscillation of Ca^(2+)concentration,reactive oxygen species(ROS)burst and protein kinase activity,lead to plant hormone biosynthesis and signaling.Jasmonic acid(JA)and ethylene(ET)are known to be fundamental to the induction and regulation of defense mechanisms toward invading necrotrophic pathogens.Complicated hormone crosstalk modulates the fine-tuning of transcriptional reprogramming and metabolic redirection,resulting in production of antimicrobial metabolites,enzyme inhibitors and cell wall refortification to restrict further pathogenesis.Transcriptome profiling of apple roots in response to inoculation with Pythium ultimum demonstrated that there is a high degree of conservation regarding the molecular framework of defense responses compared with those observed with foliar tissues.It is conceivable that the timing and intensity of genotype-specific defense responses may lead to different outcomes between rootstocks in response to invasion by necrotrophic pathogens.Elucidation of host defense mechanisms is critical in developing molecular tools for genomics-assisted breeding of resistant apple rootstocks.Due to their perennial nature,use of resistant rootstocks as a component for disease management might offer a durable and cost-effective benefit to tree performance than the standard practice of soil fumigation for control of ARD.
基金sponsored by the National 973 Program of China (2009CB118906, 2006CB101907)the National 863 Program of China (2006AA10A211,2008AA10Z414)the National Natural Science Foundation of China (30671048, 30671384)
文摘The study was conducted to make clear the activity of azoxystrobin to 4 plant pathogens and the synergistic effects of salicylhydroxamic acid (SHAM), which acted on the alternative oxidase. It was also conducted to be aware of the mechanism of azoxystrobin in inhibition on mycelial respiration and the influence of SHAM. The activity test of azoxystrobin and SHAM was carried out with a mycelial linear growth test and spore germination test. Other related biological properties were also observed. Inhibition of azoxystrobin and SHAM on 4 pathogens was determined by using SP-II oxygraph system. Azoxystrobin inhibited mycelial growth in Colletotrichum capsici, Botrytis cinerea, Rhizoctonia solani, and Magnaporthe grisea, respectively; it also inhibited conidia germination, and conidia production in C. capsici, B. cinerea M. grisea, and sclerotia formation in R. solani. Moreover, it created stayed pigment biosynthesis in C. capsici and M. grisea somehow. Salicylhydroxamic acid enhanced inhibition by azoxystrobin. An oxygen consuming test of the mycelia showed that azoxystrobin inhibited all the 4 fungi's respiration in the early stages. With the concentration rising up, the effectiveness increased. However, as time went on, the respiration of the mycelia treated with fungicides recovered and SHAM could not inhibit the oxygen consuming. This reaction between the mycelia and the fungicides appeared not to initiate alternative respiration but rather the other mechanism created a lack of efficacy.
文摘In dairy and food industries lactic acid bacteria (LAB) have been used in form of starter culture that plays vital role in fermentation; as flavouring and texturizing or as preservative agents. There is increasing evidence that lactobacilli which inhabit the gastrointestinal tract develop antimicrobial activities and participate in the host's defence system[1]. During fermentation, most of the LAB produces a number of different compounds like organic acids, hydrogen peroxide, diacetyl, acetaldehyde, carbon dioxide, polysaccharides, and proteinaceous compounds called bacteriocins or bacteriocinogenic peptides.
文摘Silver nanoparticles have mainly been studied for their antimicrobial potential against bacteria, but have also proven to be active against several types of viruses, even against pebrine as well. Methods: Petri dishes and transmission electronic microscope were applied to observe silver nanoparticles against bacteria strains and nuclear polyhedral viruses (NPV) and cytoplasmic polyhedral viruses (CPV). For biological test, 108 CFU/mL NPV with strong pathogenicity, and the NPV samples treated with 1:100 ratio of “Sumerian Silver” for 8 hrs were sprayed on the mulberry leaves, respectively, for silkworm rearing. Conclusion: Silver nanoparticle solution showed a strong bactericidal effect against both G+ and G﹣bacterial pathogenic strains from Bombyx mori and mulberry. Under transmission electronic microscope (TEM), Bacillus sp. Samples showed light particles in the cells when treated with silver nanoparticles, in contrast, untreated samples showed homogeneity contents. Further, NPV particles showed no significant differences between treated and untreated samples, but CPV showed strong effects that almost all CPV were collapsed. For biological test, “Sumerian Silver” treated NPV showed no diseased silkworm but nearly all silkworms were dead with no treatment. It seems like that silver nanoparticles were proved to be more effective against CPV than that of NPV. The significant differences between two antivirus or virucidal mechanism should be greatly aroused the scientific interest.