Study On The Serotype And Drug Resistance Of Foodborne Salmonella In Beef And Mutton And Its Meat Products In Urumqi

This study focus on the infection condition of Salmonella which collected from beef,mutton,baked samosa and beef balls in 2016-2017,furthermore,the serotype,drug sensitivity and resistance related plasmid mediated gene of quinolone antibiotics of above Salmonella isolates was carried out in deep study,the results were follows:1.153(4.3%)samples of 3565 meat and meat samples collected from seven districts of Urumqi were Salmonella positive,and the infection rates of Salmonella in the samples of Shayibake District,Midong District,Shuimogou District,Xinshi District,Changji District,Tianshan and Toutunhe District were 9.1%,5.9%,4.4%,3.5%,2.5%,2.0% and 2.0%,respectively.Among them,the food borne Salmonella in beef and mutton and its meat productsin Shah Bea Barker region was more severe.Moreover,the highest detection rate of Salmonella was the mutton samples and the positive detection rate reached 7.4%.The positive detection rates of Salmonella in beef,beef balls and baked samosa samples were 5.2%,2.9% and 2.1%,respectively.2.The serotype of four types of Salmonella from beef and mutton and its meat productsin Urumqi is diverse and 14 serotypes were isolated from 153 Salmonella strains.Among the 14 kinds of serotypes,the most common is Salmonella Hadar(50,32.7%),followed by Salmonella London(24,15.7%),Salmonella Enteritidis(20,13.1%),Salmonella Havana(10,6.5%),Salmonella Derby(9,5.9%),Salmonella Mbandaka(9,5.9%)and Salmonella Paratyphi B(8,5.2%),respectively.Furthermore,some rare serotypes were found,such as Salmonella Braenderup?Salmonella Tennessee and Salmonella Bloomsbury.3.Salmonella from four types of beef and mutton and its meat productsis resistant to some commonly used antibiotics.The 153 isolates were 100% resistant to trimethoprim,and were sensitive to ciprofloxacin and did not produce resistance.The resistance rate of other tested antibiotics was chloramphenicol 92.2%,nalidixacid 70.6%,tetracycline 64.1%,sulfamethoxazole 57.5%,trimethoprim /sulfamethoxazole 43.8%,streptomycin 28.1%,cefoxitin 12.4%.Kanamycin 11.8%,amoxicillin / clavulanic acid 11.1%,Amikacin 7.8%,gentamicin 7.2%,ceftriaxone 6.5%,respectively.Moreover,among the 153 strains of Salmonella,the resistance rate of the least 1 antibiotics was 153(100%),4 and more kinds of antibiotics was 104(68%),and 7 and more kinds of antibiotics was 57(37.3%).In addition,the 1-3 antibiotic resistance rates was 32%(49 strains),4-6 antibiotic resistance rates was 30.7%(47strains),7-9 antibiotic resistance rates was 32.7%(50 strains),10 antibiotic resistance rates was 4.6%(7 strains),and 11 and more11 antibiotics were not found.Compared to other isolated serotypes of Salmonella,three common serotypes including Salmonella Hadar,Salmonella Enteritidis and Salmonella Derby were more resistant to antibiotics.4.206 amino acid point mutations were detected in 153 Salmonella isolates including 85 subunit mutation in helicase gyr A and 121 subunit mutation in topoisomerase par C.Ser83 Phe and Asp87 Tyr are common mutations in gyr A gene,Thr57 Ser is the most common mutation in par C gene.In addition,it is found that 55 strains represent same mutation of gyr A and par C gene in Ser83Phe(gyr A)-Thr57Ser(par C).Among the 105 strains resistant to nolidipyridine acid,the detection rates of plasmid mediated fluoroquinolones was highest,the detection rate of qnr B was highest which can reach 26.8%.The detection rates of oqx A,oqx B,qep A,qnr A,qnr S and aac(6')-Ib-cr were respectively 13.7%,11.8%,11.8%,11.1%,9.2% and 7.2%.