从50家宠物诊所收集的6,223份宠物直肠样本中,共回收了334株沙门氏菌,42家宠物店,7个住宅区,4个广场鉴定出40个血清变型,其中包括所有菌株,除了一个未通过自凝集聚集的分离株,带有鼠伤寒沙门氏菌单相变体,肯塔基沙门氏菌,肠炎沙门氏菌,波莫纳沙门氏菌,沙门氏菌是主要的血清型。在分离株中鉴定出51种序列类型,最常见的是ST198、ST11、ST19、ST451、ST34和ST155。分离株耐药前四位的主要抗菌药物是磺胺异恶唑,氨苄青霉素,多西环素,和四环素,217株分离株表现出多药耐药性。沙门氏菌中β-内酰胺酶基因的患病率为59.6%,在这些分离物中,185藏有blaTEM,其次是blaCTX-M(66)和blaOXA(10)。此外,六个PMQR基因,即,包括qnrA(4.8%),qnrB(4.2%),qnrD(0.9%),qnrS(18.9%),aac(6')-Ib-cr(16.5%),和OQXB(1.5%),被检测到。QRDR突变(76.6%)在沙门氏菌分离株中非常常见,在parC(T57S)中最常见的突变(47.3%)。此外,我们在176个分离株中检测到6个四环素抗性基因,即,tet(A)(39.5%),tet(B)(8.1%),tet(M)(7.7%),tet(D)(5.4%),tet(J)(3.3%),和tet(C)(1.8%),和303个分离株中的三个磺酰胺抗性基因,即,sul1(84.4%),sul2(31.1%),和sul3(4.2%)。最后,我们发现86株同时携带4种抗性基因,这些抗性基因将2-7种抗性基因共同转移给受体细菌。耐药性的频繁发生,尤其是狗和猫,这表明滥用抗生素可能会在宠物中驱动多药耐药沙门氏菌。IMPORTANCEPet相关的人类沙门氏菌病已经报道了很多年,宠物相关沙门氏菌的耐药性已成为一个严重的公共卫生问题,并受到越来越多的关注。重庆市没有宠物沙门氏菌及其耐药性的报道,中国。在这项研究中,我们调查了患病率,血清变体多样性,序列类型,重庆市宠物粪便中沙门菌分离株的耐药性分析.此外,β-内酰胺酶,QRDR,PMQR,四环素和磺胺类耐药基因,并检查了沙门氏菌分离株中QRDR的突变。我们的发现证明了沙门氏菌分离株的血清型和序列类型的多样性。这些分离株对抗菌药物有广泛的耐药性,特别是在多重耐药菌株比例很高的情况下,这突出了多重耐药沙门氏菌从宠物到人类的潜在直接或间接传播。此外,抗性基因在分离株中广泛流行,大多数抗性基因在菌株之间水平传播。
A total of 334 Salmonella isolates were recovered from 6,223 pet rectal samples collected at 50 pet clinics, 42 pet shops, 7 residential areas, and 4 plazas. Forty serovars were identified that included all strains except for one isolate that did not cluster via self-agglutination, with Salmonella Typhimurium monophasic variant, Salmonella Kentucky, Salmonella Enteritidis, Salmonella Pomona, and Salmonella Give being the predominant serovars. Fifty-one sequence types were identified among the isolates, and ST198, ST11, ST19, ST451, ST34, and ST155 were the most common. The top four dominant antimicrobials to which isolates were resistant were sulfisoxazole, ampicillin, doxycycline, and tetracycline, and 217 isolates exhibited multidrug resistance. The prevalence of β-lactamase genes in Salmonella isolates was 59.6%, and among these isolates, 185 harbored blaTEM, followed by blaCTX-M (66) and blaOXA (10). Moreover, six PMQR genes, namely, including qnrA (4.8%), qnrB (4.2%), qnrD (0.9%), qnrS (18.9%), aac(6\')-Ib-cr (16.5%), and oqxB (1.5%), were detected. QRDR mutations (76.6%) were very common in Salmonella isolates, with the most frequent mutation in parC (T57S) (47.3%). Furthermore, we detected six tetracycline resistance genes in 176 isolates, namely, tet(A) (39.5%), tet(B) (8.1%), tet(M) (7.7%), tet(D) (5.4%), tet(J) (3.3%), and tet(C) (1.8%), and three sulfonamide resistance genes in 303 isolates, namely, sul1 (84.4%), sul2 (31.1%), and sul3 (4.2%). Finally, we found 86 isolates simultaneously harboring four types of resistance genes that cotransferred 2-7 resistance genes to recipient bacteria. The frequent occurrence of antimicrobial resistance, particularly in dogs and cats, suggests that antibiotic misuse may be driving multidrug-resistant Salmonella among pets.IMPORTANCEPet-associated human salmonellosis has been reported for many years, and antimicrobial resistance in pet-associated Salmonella has become a serious public health problem and has attracted increasing attention. There are no reports of Salmonella from pets and their antimicrobial resistance in Chongqing, China. In this study, we investigated the prevalence,
serovar diversity, sequence types, and antimicrobial resistance of Salmonella strains isolated from pet fecal samples in Chongqing. In addition, β-lactamase, QRDR, PMQR, tetracycline and sulfonamide resistance genes, and mutations in QRDRs in Salmonella isolates were examined. Our findings demonstrated the diversity of serovars and sequence types of Salmonella isolates. The isolates were widely resistant to antimicrobials, notably with a high proportion of multidrug-resistant strains, which highlights the potential direct or indirect transmission of multidrug-resistant Salmonella from pets to humans. Furthermore, resistance genes were widely prevalent in the isolates, and most of the resistance genes were spread horizontally between strains.