Updated roles of the gut microbiota in exploring shrimp etiology, polymicrobial pathogens, and disease incidence

Litopenaeus vannamei is the most extensively cultured shrimp species globally,recognized for its scale,production,and economic value.However,its aquaculture is plagued by frequent disease outbreaks,resulting in rapid and massive mortality.etiological research often lags behind the emergence of new diseases,leaving the causal agents of some shrimp diseases unidentified and leading to nomenclature based on symptomatic presentations,especially in cases involving co-and polymicrobial pathogens.Comprehensive data on shrimp disease statuses remain limited.In this review,we summarize current knowledge on shrimp diseases and their effects on the gut microbiome.Furthermore,we also propose a workflow integrating primary colonizers,“driver”taxa in gut networks from healthy to diseased states,disease-discriminatory taxa,and virulence genes to identify potential polymicrobial pathogens.We examine both abiotic and biotic factors(e.g.,external and internal sources and specific-disease effects)that influence shrimp gut microbiota,with an emphasis on the“holobiome”concept and common features of gut microbiota response to diverse diseases.After excluding the effects of confounding factors,we provide a diagnosis model for quantitatively predicting shrimp disease incidence using disease common-discriminatory taxa,irrespective of the causal agents.Due to the conservation of functional genes used in designing specific primers,we propose a practical strategy applying qPCR-assayed abundances of disease common-discriminatory functional genes.This review updates the roles of the gut microbiota in exploring shrimp etiology,polymicrobial pathogens,and disease incidence,offering a refined perspective for advancing shrimp aquaculture health management.

Prevalence of Enteric Pathogens Associated with Infections among Table Egg Consumers in Some Primary Health Establishments in the Center Region of Cameroon

Method: In Cameroon limited data are available regarding the prevalence of enteric bacteria associated with table egg consuming infections. As such, a situational-based study was performed in patients with complains of stomach disorders after egg consumption. Data related to sociodemographic characteristics and other factors were collected using a structured based questionnaire. Stool culture of utmost importance in stomach disorders patients and serum were collected for typhoid serological test. Results: A total of 207 participants took part in the survey, Results indicated nontyphoidal Salmonella infections were highest in the 3 areas of study with Mfoundi (73.44%) having the highest level of infection compared to other bacterial infection. other enteric bacteria associated to this infection were E. coli serotype 157, Aeromonas, Citrobacter freundii, Enterobacter cloaca and typhi salmonella. Meanwhile salmonelosis caused by typhic salmonella had highest prevalence in the Lekie Division (13.11%) as a result of poor hygienic practices associated with the conservation and preparation of eggs, Stool culture was observed to detect more positive cases in the diagnosis of typhoid fever than Widal test, but with no statistically significant (p > 0.05) difference between the stool culture and Widal test in the 3 areas of study. Conclusion: this study revealed that egg consumers are pruned to enteric bacterial and salmonella infections depending on how and where egg is consumed.

Research Progress on Pathogens of Main Diseases of Dictyophora rubrovalvata and Their Occurrence

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.

A Natural Catalytic Converter® for Continuously Inactivating Air and Surface Pathogens with More Effect than Ventilation and Filtration

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.

Antifungal alkaloids from Mahonia fortunei against pathogens of postharvest fruit

Postharvest pathogens can affect a wide range of fresh fruit and vegetables,including grapes,resulting in significant profit loss.Isoquinoline alkaloids of Mahonia fortunei,a Chinese herbal medicine,have been used to treat infectious microbes,which might be effective against postharvest pathogens.The phytochemical and bioactive investigation of this plant led to the isolation of 18 alkaloids,of which 9 compounds inhibited the growth of Botrytis cinerea and 4 compounds against Penicillium italicum.The antifungal alkaloids could change the mycelium morphology,the total lipid content,and leak the cell contents of B.cinerea.Furthermore,the two most potent antifungal alkaloids,berber-ine(13)completely inhibited effect on gray mold of table grape at 512 mg L^(−1),while jatrorrhizine(18)exhibited an inhibition rate>90%on grape rot at the same concentration,with lower cytotoxicity and residue than chlorothalonil,which suggested that ingredients of M.fortunei might be a low-toxicity,low-residue,eco-friendly botanical fungicide against postharvest pathogens.

Review on microbial metabolomics of probiotics and pathogens:Methodologies and applications

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.

The Role of Biosynthesized Metallic and Metal Oxide Nanoparticles in Combating Anti-Microbial Drug Resilient Pathogens

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.

Prevalence of Antimicrobial Resistance of ESKAPE Pathogens before and during Pandemic COVID-19 Pandemic in a University Affiliated Hospital in Tangerang, Indonesia

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 1st, 2019 until December 31st, 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.

Characteristics of cross transmission of gut fungal pathogens between wintering Hooded Cranes and sympatric Domestic Geese

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.

A LAMP-assay-based specific microbiota analysis reveals community dynamics and potential interactions of 13 major soybean root pathogens

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.

In vitro activity of moxifloxacin and piperacillin/sulbactam against pathogens of acute cholangitis

AIM：To analyze the in vitro activity of moxifloxacin and piperacillin/sulbactam against pathogens isolated from patients with acute cholangitis. METHODS： In this prospective study a total of 65 patients with acute cholangitis due to biliary stone obstruction （n = 7）, benign biliary stricture （n = 16）, and malignant biliary stricture （n = 42） were investigated with regard to spectrum of bacterial infection and antibiotic resistance. Pathogens were isolated from bile cultures in all study patients. In 22 febrile patients, blood cultures were also obtained. In vitro activity of moxifloxacin and piperacillin/ sulbactam was determined by agar diffusion. RESULTS： Thirty-one out of 65 patients had positive bile and/or blood cultures. In 31 patients, 63 isolates with 17 different species were identified. The predominant strains were Enterococcus species （26/63）, Ecoli （13/63） and Klebsiella species （8/63）. A comparable in vitro activity of moxifloxacin and piperacillin/sulbactam was observed for E.coli and Klebsiella species. In contrast, Enterococcus species had higher resistances towards moxifloxacin. Overall bacteria showed antibiotic resistances in vitro of 34.9% for piperacillin/sulbactam and 36.5% for moxifioxacin.CONCLUSION： Enterococcus species, E.co/i and Klebsiella species were the most common bacteria isolated from bile and/or blood from patients with acute cholangitis. Overall, a mixed infection with several species was observed, and bacteria showed a comparable in vitro activity for piperacillin/sulbactam and moxifloxacin.

Simultaneous Detection of 13 Key Bacterial Respiratory Pathogens by Combination of Multiplex PCR and Capillary Electrophoresis

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.

Anaerobic soil disinfestation:A chemical-independent approach to pre-plant control of plant pathogens

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.

The effect of leaves extracts of Clitoria ternatea Linn against the fish pathogens

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.

The frequency and antimicrobial resistance patterns of nosocomial pathogens recovered from cancer patients and hospital environments

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.

Market Disease Pathogens Detection of Imported Fruits in Shanghai

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.

Quantification of Zoonotic Bacterial Pathogens within Commercial Poultry Processing Water Samples Using Droplet Digital PCR

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.

Pediococcus Acidilactici Inhibit Biofilm Formation of Food-Borne Pathogens on Abiotic Surfaces

In this study, we aimed to examine the inhibitory effect of PA003, a Pediococcus acidilactici that produces lactic acid and antimicrobial peptides pediocin, on pathogenic biofilm formation on abiotic surfaces. PA003 and pathogens (Escherichia coli, Salmonella enterica serovar Typhimurium, Staphylococcus aureus and Listeria monocytogenes) were used to evaluate auto-aggregation, hydrophobicity, biofilm formation and biofilm formation inhibition on stainless steel, polyvinyl chloride and glass slides in terms of exclusion, displacement and competition. The results showed the highest auto-aggregation abilities were observed for one of the E. coli strains EAggEC (E58595) and the highest hydrophobic strain was observed with EPEC (E2348/69) (51.9%). The numbers of biofilm cells of E. coli, S. Typhimurium, S. aureus and L. monocytogenes on stainless steel, polyvinyl chloride and glass slide coupons were effectively reduced by approximately 4 log CFU/coupon. These results demonstrate that lactic acid bacteria can be used as an alternative to effectively control the formation of biofilms by food-borne pathogens. © 2016, Tianjin University and Springer-Verlag Berlin Heidelberg.

Rapid detection of intestinal pathogens in fecal samples by an improved reverse dot blot method

AIM:To develop a new, rapid and accurate reverse dot blot(RDB) method for the detection of intestinal pathogens in fecal samples.METHODS:The 12 intestinal pathogens tested were Salmonella spp., Brucella spp., Escherichia coli O157:H7, Clostridium botulinum , Bacillus cereus , Clostridium perfringens , Vibrio parahaemolyticus , Shigella spp., Yersinia enterocolitica, Vibrio cholerae, Listeria monocytogenes and Staphylococcus aureus.The two universal primers were designed to amplify two variable regions of bacterial 16S and 23S rDNA genes from all of the 12 bacterial species tested.Five hundred and forty fecal samples from the diarrhea patients were detected using the improved RDB assay.RESULTS:The methods could identify the 12 intestinal pathogens specifi cally, and the detection limit was as low as 103 CFUs.The consistent detection rate of the improved RDB assay compared with the traditional culture method was up to 88.75%.CONCLUSION:The hybridization results indicated that the improved RDB assay developed was a reliable method for the detection of intestinal pathogen in fecal samples.

The role of the MAP kinase−kinase protein StMKK1 in potato immunity to different pathogens

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.