Diversity Analysis Of Endophytic Bacteria And Study On Antibiotic Resistance Of Edible Fungi In Yunnan

At present,the research on the endophytic bacteria of edible fungi mainly focuses on the antibacterial activity and metabolites,so it has certain significance to the research on the structural diversity of endophytic bacteria in edible fungi.In addition,there are some limitations in the traditional culture methods and the biological morphology identification methods.It is more convenient and accurate to use modern molecular biotechnology to identify and analyze endophyte colonies.In this study,8 kinds of wild edible fungus in Yunnan Province were selected as the research objects.The endophytic bacteria were isolated and identified by traditional culture and molecular biotechnology.Then,we assembled the genes of the rare foodborne pathogens and analyzed the resistance genes,mechanism and virulence factors.At the same time,the antibiotics resistance of the isolates to 18 kinds of antibiotics was studied,phenotypes and genotypes were analyzed by gene annotation.The main results are as follows:1.Edible fungus in Yunnan Province is the research object,5 were Lactarius,2 were Russulavirescens and 1 was Cantharelluscibarius Fr.,they were plucked from different places.the kit method is selected to extract bacterial genomic DNA.At last,56 bacteria strains were isolated from seven kinds of edible fungus,belonging to 14 species.Pseudomonas,Cedecea,Serratia and lelliottia were the dominant groups.The data analysis showed that there were differences and similarities of colony structure in different kinds of edible fungi and the same species edible fungi from different places.2.12 foodborne pathogens were selected for bacterial genome assembly.By analyzing gene annotation,12 foodborne pathogens were found to have diverse genome protein functions,notably amino acid transport and metabolism functions;each sample contained more than 15 resistance genes.each sample contains more than 30 virulence factors.3.The antibiotic resistance of 56 isolates was studied by K-B disk diffusion method(Kirby Bauer)and PCR detection of drug resistance genes.The results showed that the resistance rate of 56 strains to antibiotics was 98.21%for amoxicillin,94.64%for penicillin and 91.07%for vancomycin,0 for ofloxacin,1.69%for ciprofloxacin,3.57%for minocycline and 3.57%for doxycycline.The results of the detection of drugresistant genes were as follows:the highest detection rate is the sul1 gene in sulfonamides,which is as high as 53.57%;excluding the undetected strains,the lowest detection rate is sul2 and sul3 genes,which are 1.79%;the six drug-resistant genes of tetracycline only tetk and tet M were detected,8.92%and 23.21%respectively;the?-lactam detected,bla TEM,bla-vim and bla SHV were all detected,the detection rate were 25%,21.42%,and 23.21%;Among the four aminoglycoside resistant genes,aad B was not detected,the other aac(3')-IIa was 3.57%,acr B was 1.79%%,aad A1 was37.5%;chloramphenicol Cat was 14.29%,flo R was not detected;polypeptide gene van C was 3.57%,Emgr B was not detected;quinolones three genes were detected,Gyr A8.92%,Gyr B 39.29%,Par C 37.5%.The highest coincidence rate between phenotype and genotype was 90.48%for aminoglycosides and 2.94%for quinolones.In summary,the endophytic bacteria of edible fungus have diversity and difference.The isolated strains are resistant to various antibiotics in different degrees,and the resistant genes are widely existed among the isolated strains.