ISGlobal Hospital Clinic - Universitat de Barcelona, Barcelona, Spain.
Facultad de Medicina, Universidad Peruana Cayetano Heredia, Lima, Peru; Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru.
Int J Food Microbiol. 2021 Apr 16;344:109109. doi: 10.1016/j.ijfoodmicro.2021.109109. Epub 2021 Feb 23.
The objective of the present study was to characterize Salmonella enterica serovar Infantis isolated from chicken meat determining their clonal relationships with S. Infantis isolated from children with diarrhea. Fifteen meat-recovered S. Infantis were analyzed. Susceptibility levels to 14 antibacterial agents, the presence of ESBL and that of inducible plasmid-mediated AmpC (i-pAmpC) were determined by phenotypical methods. The presence of ESBL and pAmpC was confirmed by PCR, and detected ESBL-encoding genes were sequenced and their transferability tested by conjugation. The presence of gyrA mutations as well as Class 1 integrons was determined by PCR. Clonal relationships were established by REP-PCR and RAPD. In addition, 25 clinical isolates of S. Infantis were included in clonality studies. All meat-recovered S. Infantis were MDR, showing resistance to ampicillin, nitrofurans and quinolones, while none was resistant to azithromycin, ceftazidime or imipenem. ESBL (bla) and i-pAmpC (bla) were detected in 2 and 5 isolates respectively (in one case concomitantly), with bla being transferable through conjugation. In addition, 1 isolate presented a bla gene. All isolates presented DY at GyrA, nalidixic acid active efflux pump and a Class 1 integron of ~1000 bp (aadA1). Clonal analysis showed that all isolates were related. Further they were identical to MDR bla-producing S. Infantis isolates causing children diarrhea in Lima. The dissemination of MDR bla-producing S. Infantis between marketed meat and children highlights a public health problem which needs be controlled at livestock level.
本研究的目的是对从鸡肉中分离出的肠炎沙门氏菌血清型 Infantis 进行鉴定，确定其与腹泻儿童分离出的肠炎沙门氏菌 Infantis 的克隆关系。分析了 15 株从肉中分离出的肠炎沙门氏菌血清型 Infantis。采用表型方法测定了对 14 种抗菌药物的敏感性水平、ESBL 的存在情况以及可诱导质粒介导的 AmpC（i-pAmpC）的存在情况。通过 PCR 确认了 ESBL 和 pAmpC 的存在，并对检测到的 ESBL 编码基因进行了测序，通过接合试验测试了其可转移性。通过 PCR 确定了 gyrA 突变和 1 类整合子的存在。通过 REP-PCR 和 RAPD 确定了克隆关系。此外，还对 25 株临床分离的肠炎沙门氏菌血清型 Infantis 进行了克隆性研究。所有从肉中分离出的肠炎沙门氏菌血清型 Infantis 均为 MDR，对氨苄西林、呋喃妥因和喹诺酮类药物耐药，而对阿奇霉素、头孢他啶或亚胺培南均无耐药性。在 2 株和 5 株分离株中分别检测到 ESBL（bla）和 i-pAmpC（bla）（在 1 株中同时检测到），bla 可通过接合转移。此外，1 株分离株还携带 bla 基因。所有分离株在 GyrA 上均表现为 DY、萘啶酸活性外排泵和 1000bp 左右的 1 类整合子（aadA1）。克隆分析表明，所有分离株均有关联。此外，它们与引起利马儿童腹泻的多药耐药 bla 产生肠炎沙门氏菌血清型 Infantis 分离株完全相同。市场销售的肉类与儿童之间多药耐药 bla 产生肠炎沙门氏菌血清型 Infantis 的传播凸显了一个需要在牲畜层面控制的公共卫生问题。
