Bio-control of Some Food-Borne Pathogenic Bacteria by Bacteriophage

In recent years, researchers tended to bring new alternative to biological protective systems used in conservation of food and production of safe food. Use of bacteriophage against to pathogen bacteria in food was the most hopeful system in these methods about bio-control. Controls of bacteriophage for each pathogen species and subspecies and determination of phage-host originality are important because efficient bio-control was achieved. Researches concentrated on some food-borne pathogen bacteria such as E. coli O157：H7, Campylobacter, Salmonella and Listeria. In a consequence of these studies made as in vitro and in vivo, first commercial production of phage which will be used in foods was made in Netherlands. Also, it has been informed that use of phage is cost-efficient alternative as compared with other preservatives. This review, discussed application of bacteriophages as bio-control agents in food and advantages and disadvantages about uses of bacteriophages by taking into account antimicrobial characteristics of them.

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.

Quantum dot biosensor combined with antibody and aptamer for tracing food-borne pathogens

Due to the increasing number of food-borne diseases,more attention is being paid to food safety.Food-borne pathogens are the main cause of food-borne diseases,which seriously endanger human health,so it is necessary to detect and control them.Traditional detection methods cannot meet the requirements of rapid detection of food due to many shortcomings,such as being time-consuming,laborious or requiring expensive instrumentation.Quantum dots have become a promising nanotechnology in pathogens tracking and detection because of their excellent optical properties.New biosensor detection methods based on quantum dots are have been gradually developed due to their high sensitivity and high specificity.In this review,we summarize the different characteristics of quantum dots synthesized by carbon,heavy metals and composite materials firstly.Then,attention is paid to the principles,advantages and limitations of the quantum dots biosensor with antibodies and aptamers as recognition elements for recognition and capture of food-borne pathogens.Finally,the great potential of quantum dots in pathogen detection is summarized.

Antimicrobial effects of carnosic acid,kaempferol and luteolin on biogenic amine production by spoilage and food-borne pathogenic bacteria

Antimicrobial effects of carnosic acid,kaempferol and luteolin on biogenic amine(BA)production by five spoilage(Photobacterium damselae,Proteus mirabilis,Enterobacter cloacea,Pseudomonas luteola and Serratia liquefaciens)and five food-borne pathogenic bacteria(Staphylococcus aureus ATCC29213,Enterococcus faecalis ATCC29212,Escherichia coli ATCC25922,Salmonella Paratyphi A NCTC13 and Yersinia enterocolitica NCTC 11175)were investigated.The formation of ammonia(AMN),trimethylamine(TMA)and BAs by all bacterial strains were observed using ornithine decarboxylase broth.BAs,AMN,and TMA were determined by using high performance liquid chromatography(HPLC)method.The results showed that significant differences were observed(P≤0.05)in formation among spoilage and also food-borne bacteria.The impact of phenolic compounds on AMN,TMA and BAs production was dependent on bacterial strains.When total amount of cadaverine(CAD),putrescine(PUT),histamine(HIS)and tyramine(TYR)was considered,the phenolic compounds presented antimicrobial activity against fish spoliage bacteria and food-borne pathogens following the order;kaempferol>carnosic acid>luteolin.These phenolics have potential to be used as food preservatives.

Animals as sources of food-borne pathogens: A review

Food-producing animals are the major reservoirs for many foodborne pathogens such as Campylobacter species, non-Typhi serotypes of Salmonella enterica, Shiga toxin-producing strains of Escherichia coli, and Listeria monocytogenes. The zoonotic potential of foodborne pathogens and their ability to produce toxins causing diseases or even death are sufficient to recognize the seriousness of the situation. This manuscript reviews the evidence that links animals as vehicles of the foodborne pathogens Salmonella,Campylobacter, Shiga toxigenic E. coli, and L. monocytogenes, their impact, and their current status. We conclude that these pathogenic bacteria will continue causing outbreaks and deaths throughout the world, because no effective interventions have eliminated them from animals and food.

Control of highly pathogenic avian influenza through vaccination

The stamping-out strategy has been used to control highly pathogenic avian influenza viruses in many countries,driven by the belief that vaccination would not be successful against such viruses and fears that avian influenza virus in vaccinated birds would evolve more rapidly and pose a greater risk to humans.In this review,we summarize the successes in controlling highly pathogenic avian influenza in China and make suggestions regarding the requirements for vaccine selection and effectiveness.In addition,we present evidence that vaccination of poultry not only eliminates human infection with avian influenza virus,but also significantly reduces and abolishes some harmful characteristics of avian influenza virus.

Investigation of the epidemiology,pathogenicity and immunogenicity of Bordetella bronchiseptica isolated from cats and dogs in China from 2021 to 2023

Bordetella bronchiseptica(Bb)is recognized as a leading cause of respiratory diseases in dogs and cats.However,epidemiological data on Bb in dogs and cats in China are still limited,and there is no commercially available vaccine.Live vaccines containing Bb that are widely used abroad are generally efective but can establish latency and potentially reactivate to cause illness in some immunodefcient vaccinated recipients,raising safety concerns.In this study,34 canine-derived and two feline-derived Bb strains were isolated from 1809 canine and 113 feline nasopharyngeal swab samples collected from eight provinces in China from 2021 to 2023.The PCR results showed that the percentage of positive Bb was 22.94%(441/1922),and more than 90%of the Bb isolates had four virulence factor-encoding genes(VFGs),namely,fhaB,prn,betA and dnt.All the isolated strains displayed a multidrug-resistant phenotype.The virulence of 10 Bb strains isolated from dogs with respiratory symptoms was tested in mice,and we found that eight isolates were highly virulent.Furthermore,the eight Bb isolates with high virulence were inactivated and intramuscularly injected into mice,and three Bb strains(WH1218,WH1203 and WH1224)with the best protective efcacy were selected.Dogs immunized with these three strains exhibited strong protection against challenge with the Bb feld strain WH1218.Ultimately,the WH1218 strain with the greatest protection in dogs was selected as the vaccine candidate.Dogs and cats that received a vaccine containing 109 CFU of the inactivated WH1218 strain showed complete protection against challenge with the Bb feld strain WH1218.This study revealed that Bb is an important pathogen that causes respiratory diseases in domestic dogs and cats in China,and all the isolates exhibited multidrug resistance.The present work contributes to the current understanding of the prevalence,antimicrobial resistance,and virulence genes of Bb in domestic dogs and cats.Additionally,our results suggest that the WH1218 strain is a promising candidate safe and efcacious inactivated Bb vaccine.

Modern approaches for detection of volatile organic compounds in metabolic studies focusing on pathogenic bacteria:Current state of the art

Pathogenic microorganisms produce numerous metabolites,including volatile organic compounds(VOCs).Monitoring these metabolites in biological matrices(e.g.,urine,blood,or breath)can reveal the presence of specific microorganisms,enabling the early diagnosis of infections and the timely implementation of tar-geted therapy.However,complex matrices only contain trace levels of VOCs,and their constituent com-ponents can hinder determination of these compounds.Therefore,modern analytical techniques enabling the non-invasive identification and precise quantification of microbial VOCs are needed.In this paper,we discuss bacterial VOC analysis under in vitro conditions,in animal models and disease diagnosis in humans,including techniques for offline and online analysis in clinical settings.We also consider the advantages and limitations of novel microextraction techniques used to prepare biological samples for VOC analysis,in addition to reviewing current clinical studies on bacterial volatilomes that address inter-species in-teractions,the kinetics of VOC metabolism,and species-and drug-resistance specificity.

Antiseptic Efficacy of A Soap Made from Biosurfactants Isolated from Bacillus and Lactobacillus against Pathogenic Bacteria

The aim of our study was to use a biosurfactant produced by Bacillus and Lactobacillus isolates as an antiseptic in the formulation of local soap. A total of 60 isolates were characterized by microbiological techniques (30 Bacillus and 30 Lactobacillus) and the ability to produce biosurfactants was demonstrated by a hydrocarbon emulsification index (E24). The emulsification indexes (E24) varied from 9% to 100% for Bacillus and from 33% to 100% for Lactobacillus as well. The antagonistic assay showed that biosurfactants were able to inhibit the formation of biofilms and growth of pathogens such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Salmonella typhirium, Shigella boydii and Proteus mirabilis. The biosurfactant consortium (BioC) from Bacillus consortium and from Lactobacillus was able to inhibit biofilm formation and the pathogens growth. The BioC was stable to alkaline pH and the temperatures stability of Biosurfactant was ranging from 50°C to 90°C. The soap was made by the cold saponification process using one biosurfactant consortium formulated. This soap has a pH of 10 and showed good cleaning power and good foam stability. Similarly, the soap showed good antiseptic power and disinfection power against all pathogens tested. Handwashing is critical to preventing disease transmission. The persistence of pathogens in waste water was evaluated. The BioS produced showed good disinfection power against all pathogens tested. The valor of reduction on the hands and in the waste water was significantly more than compared to the control soaps used. This soap could be used in the prevention, fighting, and treatment of bacterial and viral infections.

The virulence regulator AbsR in avian pathogenic Escherichia coli has pleiotropic effects on bacterial physiology

Avian pathogenic Escherichia coli(APEC)belonging to extraintestinal pathogenic E.coli(ExPEC)can cause severe infections in extraintestinal tissues in birds and humans,such as the lungs and blood.MprA(microcin production regulation,locus A,herein renamed AbsR,a blood survival regulator),a member of the MarR(multiple antibiotic resistance regulator)transcriptional regulator family,governs the expression of capsule biosynthetic genes in human ExPEC and represents a promising druggable target for antimicrobials.However,a deep understanding of the AbsR regulatory mechanism as well as its regulon is lacking.In this study,we present a systems-level analysis of the APEC AbsR regulon using ChIP-Seq(chromatin immunoprecipitation sequencing)and RNA-Seq(RNA sequencing)methods.We found that AbsR directly regulates 99 genes and indirectly regulates 667 genes.Furthermore,we showed that:1)AbsR contributes to antiphagocytotic effects by macrophages and virulence in a mouse model for systemic infection by directly activating the capsular gene cluster;2)AbsR positively impacts biofilm formation via direct regulation of the T2SS(type II secretion system)but plays a marginal role in virulence;and 3)AbsR directly upregulates the acid tolerance signaling system EvgAS to withstand acid stress but is dispensable in ExPEC virulence.Finally,our data indicate that the role of AbsR in virulence gene regulation is relatively conserved in ExPEC strains.Altogether,this study provides a comprehensive analysis of the AbsR regulon and regulatory mechanism,and our data suggest that AbsR likely influences virulence primarily through the control of capsule production.Interestingly,we found that AbsR severely represses the expression of the type I-F CRISPR(clustered regularly interspaced short palindromic repeats)-Cas(CRISPR associated)systems,which could have implications in CRISPR biology and application.

SsdchA is a novel secretory cellobiohydrolase driving pathogenicity in Sclerotinia sclerotiorum

The necrotrophic fungus, Sclerotinia sclerotiorum, employs an array of cell wall-degrading enzymes(CWDEs), including cellulase, to dismantle host cell walls. However, the molecular mechanisms through which S. sclerotiorum degrades cellulose remain elusive. Here, we unveil a novel secretory cellobiohydrolase, SsdchA, characterized by a signal peptide and a Glyco_hydro_7(GH7) domain. SsdchA exhibits a robust expression of during early infection stages. Interestingly, colony morphology and growth rates remain unaffected across the wild-type, SsdchA deletion strains and SsdchA overexpression strains on potato dextrose agar(PDA) medium. Nevertheless, the pathogenicity and cellobiohydrolase activity decreased in the SsdchA deletion strains, but enhanced in the SsdchA overexpression strains. Moreover,the heterologous expression of SsdchA in Arabidopsis thaliana leads to reduced cellulose content and heightened susceptibility to S. sclerotiorum. Collectively, our data underscore the pivotal role of the novel cellobiohydrolase SsdchA in the pathogenicity of S. sclerotiorum.

Autophagy-related protein PlAtg3 participates in vegetative growth,sporangial cleavage,autophagy and pathogenicity of Peronophythora litchii

Litchi downy blight,caused by the plant pathogenic oomycete Peronophythora litchii,is one of the most devastating diseases on litchi and resulted in huge economic losses.Autophagy plays an essential role in the development and pathogenicity of the filamentous fungi.However,the function of autophagy in oomycetes remain elusive.Here,an autophagy-related protein Atg3 homolog PlAtg3 was identified and characterized in P.litchii.The absence of PlATG3 through the CRISPR/Cas9 gene replacement strategy compromised vegetative growth and sexual/asexual development.Cytological analyses revealed that the deletion of PlATG3 impaired autophagosome formation with monodansylcadaverine(MDC)staining and significantly disrupted zoospore release due to defects of sporangial cleavage with FM4-64 staining.Atg8 is considered to be an autophagy marker protein in various species.Western blot analysis indicated that PlAtg3 is involved in degradation of PlAtg8-PE.Interestingly,PlAtg3 was unable to interact with PlAtg8 in yeast two hybrid(Y2H)assays,possibly due to the absence of the Atg8 family interacting motif(AIM)in PlAtg3.Furthermore,pathogenicity assays revealed that the deletion of PlATG3 considerably reduced the virulence of P.litchii.Taken together,our data reveal that PlAtg3 plays an important role in radial growth,asexual/sexual development,sporangial cleavage and zoospore release,autophagosome formation,and pathogenicity in P.litchii.This study contributes to a better understanding of the pathogenicity mechanisms of P.litchii and provides insights for the development of more effective strategies to control oomycete diseases.

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.

Disruption of non-classically secreted protein(MoMtp)compromised conidiation,stress homeostasis,and pathogenesis of Magnaporthe oryzae

Blast disease,caused by the hemibiotrophic ascomycete fungus,Magnaporthe oryzae,is a significant threat to sustainable rice production worldwide.Studies have shown that the blast fungus secretes vast arrays of functionally diverse proteins into the host cell for a successful disease progression.However,the final destinations of these effector proteins inside the host cell and their role in advancing fungal pathogenesis remain a mystery.Here,we reported that a putative mitochondrial targeting non-classically secreted protein(MoMtp)positively regulates conidiogenesis and appressorium maturation in M.oryzae.Moreover,MoM TP gene deletion mutant strains triggered a hypersensitive response when inoculated on rice leaves displaying that MoMtp is essential for the virulence of M.oryzae.In addition,cell wall and oxidative stress results indicated that MoMtp is likely involved in the maintenance of the structural integrity of the fungus cell.Our study also demonstrates an upregulation in the expression pattern of the MoMTP gene at all stages of infection,indicating its possible regulatory role in host invasion and the infectious development of M.oryzae.Furthermore,Agrobacterium infiltration and sheath inoculation confirmed that MoMtpGFP protein is predominantly localized in the host mitochondria of tobacco leaf and rice cells.Taken together,we conclude that MoMtp protein likely promotes the normal conidiation and pathogenesis of M.oryzae and might have a role in disturbing the proper functioning of the host mitochondria during pathogen invasion.

The DNA damage repair complex MoMMS21-MoSMC5 is required for infection-related development and pathogenicity of Magnaporthe oryzae

The conserved DNA damage repair complex,MMS21-SMC5/6(Methyl methane sulfonate 21-Structural maintenance of chromosomes 5/6),has been extensively studied in yeast,animals,and plants.However,its role in phytopathogenic fungi,particularly in the highly destructive rice blast fungus Magnaporthe oryzae,remains unknown.In this study,we functionally characterized the homologues of this complex,MoMMS21 and MoSMC5,in M.oryzae.We first demonstrated the importance of DNA damage repair in M.oryzae by showing that the DNA damage inducer phleomycin inhibited vegetative growth,infection-related development and pathogenicity in this fungus.Additionally,we discovered that MoMMS21 and MoSMC5 interacted in the nuclei,suggesting that they also function as a complex in M.oryzae.Gene deletion experiments revealed that both MoMMS21 and MoSMC5 are required for infection-related development and pathogenicity in M.oryzae,while only MoMMS21 deletion affected growth and sensitivity to phleomycin,indicating its specific involvement in DNA damage repair.Overall,our results provide insights into the roles of MoMMS21 and MoSMC5 in M.oryzae,highlighting their functions beyond DNA damage repair.

A novel pathogen Fusarium cuneirostrum causing common bean(Phaseolus vulgaris)root rot in China

Several fungal pathogens cause root rot of common bean,among which Fusarium spp.are the most common pathogens causing Fusarium root rot(FRR)worldwide.FRR has been becoming an increasingly severe disease of common bean in China,but the species of Fusarium spp.have remained unclear.Thus,this study was performed to identify the pathogen causing common bean root rot in Liangcheng County,Inner Mongolia,China.Nineteen Fusarium-like isolates were obtained after pathogen isolation and purification.The pathogenicity test indicated that eight isolates caused severe disease symptoms on common bean,while 11 other isolates were not pathogenic.The eight pathogenic isolates,FCL1–FCL8,were identified as Fusarium cuneirostrum by morphological characterization and phylogenetic analysis using partial sequences of EF-1α,ITS,28S,and IGS regions.Host range test showed that the representative F.cuneirostrum isolate FCL3 was also pathogenic to mung bean,while not pathogenic to adzuki bean,chickpea,cowpea,faba bean,pea,and soybean.Moreover,50 common bean and 50 mung bean cultivars were screened for resistance to FRR,and seven highly resistant or resistant cultivars of common bean were identified,while no resistant cultivars of mung bean were screened.This study revealed that F.cuneirostrum was one of common bean FRR pathogens in Inner Mongolia and it could induce mung bean root rot as well.To our knowledge,this is the first report of F.cuneirostrum causing FRR of common bean in China.

Distribution of pathogenic bacteria and antimicrobial sensitivity of eye infections in Suzhou

AIM:To investigate the types of bacteria in patients with eye infections in Suzhou and their drug resistance to commonly used antibacterial drugs.METHODS:The clinical data of 155 patients were retrospectively collected in this study,and the pathogenic bacteria species and drug resistance of each pathogenic bacteria were analyzed.RESULTS:Among the 155 patients(age from 12 to 87 years old,with an average age of 57,99 males and 56 females)with eye infections(160 eyes:74 in the left eye,76 in the right eye and 5 in both eyes,all of which were exogenous),71(45.81%)strains were gram-positive bacteria,23(14.84%)strains were gram-negative bacteria and 61(39.35%)strains were fungi.Gram-positive bacteria were highly resistant to penicillin and erythromycin(78.87%and 46.48%respectively),but least resistant to vancomycin at 0.Gram-negative bacteria were highly resistant to cefoxitin and compound sulfamethoxazole(100%and 95.65%respectively),but least resistant to meropenem at 0.Comparison of the resistance of gram-positive and gram-negative bacteria to some drugs revealed statistically significant differences(P<0.05)in the resistance of both to cefoxitin,cotrimoxazole,levofloxacin,cefuroxime,ceftriaxone and ceftazidime,and both had higher rates of resistance to gram-negative bacteria than to gram-positive bacteria.The distribution of bacterial infection strains showed that Staphylococcus epidermidis was the most common strain in the conjunctiva,cornea,aqueous humor or vitreous body and other eye parts.Besides,Fusarium and Pseudomonas aeruginosa were also among the most common strains of conjunctival and corneal infections.CONCLUSION:Gram-positive bacteria are the dominant bacteria in eye infections,followed by gram-negative bacteria and fungi.Considering the resistance of gramnegative bacteria to multiple drugs,monitoring of bacteria should be strengthened in eye bacterial infections for effective prevention and control to reduce complications caused by eye infections.

Identification and characterization of FpRco1 in regulating vegetative growth and pathogenicity based on T-DNA insertion in Fusarium pseudograminearum

Fusarium pseudograminearum is a devastating pathogen that causes Fusarium crown rot(FCR)in wheat and poses a significant threat to wheat production in terms of grain yield and quality.However,the mechanism by which F.pseudograminearum infects wheat remains unclear.In this study,we aimed to elucidate these mechanisms by constructing a T-DNA insertion mutant library for the highly virulent strain WZ-8A of F.pseudograminearum.By screening this mutant library,we identified nine independent mutants that displayed impaired pathogenesis in barley leaves.Among these mutants,one possessed a disruption in the gene FpRCO1 that is an ortholog of Saccharomyces cerevisiae RCO1,encoding essential component of the Rpd3S histone deacetylase complex in F.pseudograminearum.To further investigate the role of FpRCO1 in F.pseudograminearum,we employed a split-marker approach to knock out FpRCO1 in F.pseudograminearum WZ-8A.FpRCO1 deletion mutants exhibit reduced vegetative growth,conidium production,and virulence in wheat coleoptiles and barley leaves,whereas the complementary strain restores these phenotypes.Moreover,under stress conditions,the FpRCO1 deletion mutants exhibited increased sensitivity to NaCl,sorbitol,and SDS,but possessed reduced sensitivity to H_(2)O_(2)compared to these characteristics in the wild-type strain.RNA-seq analysis revealed that deletion of FpRCO1 affected gene expression(particularly the downregulation of TRI gene expression),thus resulting in significantly reduced deoxynivalenol(DON)production.In summary,our findings highlight the pivotal role of FpRCO1 in regulating vegetative growth and development,asexual reproduction,DON production,and pathogenicity of F.pseudograminearum.This study provides valuable insights into the molecular mechanisms underlying F.pseudograminearum infection in wheat and may pave the way for the development of novel strategies to combat this devastating disease.

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.

Genetic and pathogenic characterization of new infectious bronchitis virus strains in the GVI-1 and GI-19 lineages isolated in central China

Avian infectious bronchitis(IB)is a highly contagious infectious disease caused by infectious bronchitis virus(IBV),which is prevalent in many countries worldwide and causes serious harm to the poultry industry.At present,many commercial IBV vaccines have been used for the prevention and control of IB;however,IB outbreaks occur frequently.In this study,two new strains of IBV,SX/2106 and SX/2204,were isolated from two flocks which were immunized with IBV H120 vaccine in central China.Phylogenetic and recombination analysis indicated that SX/2106,which was clustered into the GI-19 lineage,may be derived from recombination events of the GI-19 and GI-7 strains and the LDT3-A vaccine.Genetic analysis showed that SX/2204 belongs to the GVI-1 lineage,which may have originated from the recombination of the GI-13 and GVI-1 strains and the H120 vaccine.The virus cross-neutralization test showed that the antigenicity of SX/2106 and SX/2204 was different from H120.Animal experiments found that both SX/2106 and SX/2204 could replicate effectively in the lungs and kidneys of chickens and cause disease and death,and H120 immunization could not provide effective protection against the two IBV isolates.It is noteworthy that the pathogenicity of SX/2204 has significantly increased compared to the GVI-1 strains isolated previously,with a mortality rate up to 60%.Considering the continuous mutation and recombination of the IBV genome to produce new variant strains,it is important to continuously monitor epidemic strains and develop new vaccines for the prevention and control of IBV epidemics.