沙门氏菌是一种主要的食源性病原体,对食品安全和公众健康构成重大风险。这项研究旨在评估患病率,抗生素敏感性,和从600个零售肉类样品(300个猪肉,150鸡肉和150牛肉)从2018年8月到2019年10月在陕西,中国。总的来说,600份样本中有40份(6.67%)沙门氏菌阳性,鸡的患病率最高(21.33%,32/150),其次是猪肉(2.67%,8/300),而牛肉中没有检测到沙门氏菌。在40株沙门菌中检测到10种血清型和11种序列型(STs),最常见的是ST198S肯塔基州(n=15),ST13S.Agona(n=6),和ST17S.印第安纳州(n=5)。耐药性最常见的是四环素(82.50%),其次是氨苄青霉素(77.50%),萘啶酸(70.00%),卡那霉素(57.50%),头孢曲松(55.00%),头孢噻肟(52.50%),头孢哌酮(52.50%),氯霉素(50.00%),左氧氟沙星(57.50%),头孢噻肟(52.50%),卡那霉素(52.50%),氯霉素(50.00%),环丙沙星(50.00%),和左氧氟沙星(50.00%)。所有ST198S.Kucky分离株均显示多药耐药(MDR;≥3种抗菌类别)模式。基因组分析显示,在40个沙门氏菌分离株中,有56个不同的抗生素抗性基因(ARGs)和6个喹诺酮抗性决定区(QRDRs)的靶基因突变,其中,最普遍的ARG类型与氨基糖苷类和β-内酰胺类耐药有关,QRDR中最常见的突变是GyrA(S83F)(47.5%)。沙门氏菌分离株中ARG的数量与插入序列(ISs)和质粒复制子的数量呈显着正相关。一起来看,我们的发现表明零售鸡被严重污染,而猪肉和牛肉很少被沙门氏菌污染。分离株的抗生素抗性决定因素和遗传关系为食品安全和公共卫生保障提供了重要数据。
Salmonella is a major foodborne pathogen that poses a substantial risk to food safety and public health. This study aimed to assess the prevalence, antibiotic susceptibility, and genomic features of Salmonella isolates recovered from 600 retail meat samples (300 pork, 150 chicken and 150 beef) from August 2018 to October 2019 in Shaanxi, China. Overall, 40 (6.67 %) of 600 samples were positive to Salmonella, with the highest prevalence in chicken (21.33 %, 32/150), followed in pork (2.67 %, 8/300), while no Salmonella was detected in beef. A total of 10 serotypes and 11 sequence types (STs) were detected in 40 Salmonella isolates, with the most common being ST198 S. Kentucky (n = 15), ST13 S. Agona (n = 6), and ST17 S. Indiana (n = 5). Resistance was most commonly found to tetracycline (82.50 %), followed by to ampicillin (77.50 %), nalidixic acid (70.00 %), kanamycin (57.50 %), ceftriaxone (55.00 %), cefotaxime (52.50 %), cefoperazone (52.50 %), chloramphenicol (50.00 %), levofloxacin (57.50 %), cefotaxime (52.50 %), kanamycin (52.50 %), chloramphenicol (50.00 %), ciprofloxacin (50.00 %), and levofloxacin (50.00 %). All ST198 S. Kentucky isolates showed multi-drug resistance (MDR; ≥3 antimicrobial categories) pattern. Genomic analysis showed 56 distinct antibiotic resistance genes (ARGs) and 6 target gene mutations of quinolone resistance determining regions (QRDRs) in 40 Salmonella isolates, among which, the most prevalent ARG types were related to aminoglycosides and β-lactams resistance, and the most frequent mutation in QRDRs was GyrA (S83F) (47.5 %). The number of ARGs in Salmonella isolates showed a significant positive correlation with the numbers of insert sequences (ISs) and plasmid replicons. Taken together, our findings indicated retail chickens were seriously contaminated, while pork and beef are rarely contaminated by Salmonella. Antibiotic resistance determinants and genetic relationships of the isolates provide crucial data for food safety and public health safeguarding.