Study On Bacterial Diversity And Drug Resistance Of Tetragenococcus Halophilus In Xuanwei Ham

The fermentation of Xuanwei ham has abundant microbial resources.In this study,the bacterial community structure in xuanwei ham was analyzed by high-throughput sequencing technology,and the bacterial community structure and composition in xuanwei ham were clarified.The total DNA of the microbes from samples obtained from two brands of Xuanwei ham were extracted with kit and SDS-CTAB method.Afterward,16 S rDNA sequencing was performed to target the 16 S rDNA gene V4 variant sequence,the composition and diversity of bacterial communities were analyzed.The bacterial diversity in Brand II was richer than that in Brand I.The DNA extracted by SDS-CTAB could show the bacterial diversity better than that extracted by the kit method.At the genus level,the dominant bacterial communities were Tetragenococcus for Brand I and Acinetobacter for Brand II.T.halophilus has an important influence on the quality and flavor of fermented food.In this study,the bacteria in Xuanwei ham were separated by traditional morphological observation and modern molecular biology methods.Finally,49 strains of T.halophilus were isolated from Xuanwei ham.Primary isolation and culture were carried out with the MRS medium,and the groEL gene and 16 S rRNA gene of T.halophilus were used for PCR amplification verification screening,and a phylogenetic tree was established to determine the strain species.T.halophilus was found as a dominant bacterium in Xuanwei ham also has the potential to act as a starter and probiotics in fermented food.However,in the context of the global spread of bacterial resistance,it is necessary to assess the antibiotic resistance of T.halophilus.In case the antibiotic resistance genes on the strain’s genome are mobilized and transferred to other bacteria.In this study,the drug-resistant phenotype was detected by K-B dipstick method,the drug resistance gene was detected by common PCR.The results showed that the 49 isolated strains were completely sensitive to penicillin,ampicillin,amoxicillin,cefradine,cefotaxime,tetracycline,minocycline,doxycycline and vancomycin;49 isolates were completely resistant to gentamicin,streptomycin,neomycin,polymyxin B,and cotrimoxazole;32 isolates were resistant to ofloxacin;4 strains were resistant to ciprofloxacin and chloramphenicol;2 strains were resistant to ceftazidime and ticarcillin.Among the 26 drug-resistant genes,five genes of acrB,blaTEM,AAda1,SuI2 and GyrB were detected,and the detection rates were 89.79%,47.7%,16.33%,77.55%,and 75.51%,respectively.