Study On The Contamination Of Antibiotic Resistant Bacteria And The Migration Risks Of Resistance Genes From The Surface Of Bulk Ready-to-eat Chicken Samples In Shanghai

chickens,and 2 to 4 orders of magnitude higher than that of other samples.Therefore,the cooking method of ready-to-eat chicken food samples is the factor that affects the number of bacteria.Thirteen antibiotic-resistant genes(tet A2,tet B1,tet C1,tet D2,tet E,tet H,tet J,tet K,tet M,tet PA,tet PB3,sul1,sul2)and a class of integrase int I were performed by Quantitative Real-time PCR,Q-PCR)technology.The results show that tet A2,tet K,tet M,sul1,sul2,and integrin int I were detected in all samples.The relative content of genes is concentrated in 10^-4?10^-2.It has been verified from the molecular level that a large number of tetracycline-resistant bacteria and sulfonamide-resistant bacteria exist on the surface of bulk ready-to-eat chicken products.The relative content of int I gene is about 10^-2copies/16S r DNA copies,indicating the risk of antibiotic resistance gene migration.Identified strains carrying drug-resistant genes include Staphylococcus sp.,A-cinetobacter sp.,Moraxella sp.,Weissella sp.,and Macrococcus caseolyticus,En-terococcus sp.,Lactococcus sp.,Pseudomonas sp.,Bacillus cibum,Firmum bacill-us,Leuconostoc mesenteroides,etc.The drug susceptibility results showed high multi-drug resistance.59.57%strains(56/94)showed resistance to at least 2 anti-biotics,and 17.02%strains(16/94)were not sensitive to 3 antibiotics.1 Acineto-bacter sp.as identified in white-cut chickens,which showed resistance to 4 antib-iotics.Among the brine chickens,1 strain of Leuconostoc sp.and 3 strains of L-actobacillus sp.were identified,which showed resistance to 4 antibiotics,2 strai-ns of Pseudom-onas sp.as having five-level resistance,and 1 strain of Sarcobac-teria sp.as having six-level resistance.The natural transformation of donor and recipient bacteria is used to study the migration of resistant genes.The results showed that of the 22 donor strai-ns,and 7 donor strains(2 Pseudomonas sp.,3 Moraxella sp.,1 Staphylococcus s-p.,1 Streptococcus pneumoniae)were successfully transformed to the recipient s-train J53 with a transformation rate of 1.94×10^-6?2.58×10^-2.The plasmidwas extracted from the zygote.It was confirmed that the plasmid-mediated resist-ance genes could migrate once again.