苏州市沙门氏菌血清型、耐药及多位点序列分型分析

Serotypes, drug resistance, and multilocus sequence types of Salmonella isolates in Suzhou

摘要:

【背景】 沙门氏菌(Salmonella)是一种人兽共患病病原菌，是引起人类感染性腹泻最常见的病原菌之一。【目的】 分析苏州市2023年分离的176株沙门氏菌的血清型、耐药情况和分子分型。【方法】 血清型鉴定采用玻片凝集法；药敏试验采用微量肉汤法；多位点序列分型(multilocus sequence typing, MLST)采用全基因组测序，测序结果与PubMLST数据库进行比对得出菌株的ST型别。【结果】 176株沙门氏菌共鉴定出了42种血清型分属于9个血清群。血清型以肠炎沙门氏菌(Salmonella enteritidis,26.70%)和鼠伤寒沙门氏菌(Salmonella typhimurium, 18.75%)为优势血清型。176株菌对氨苄西林的耐药率最高(60.23%)，其次是链霉素(47.16%)。所有菌株均对头孢他啶/阿维巴坦、美罗培南、厄他培南和阿米卡星敏感。多重耐药率达到57.39%，多重耐药模式达到51种，其中包含青霉素类+β-内酰胺/β-内酰胺抑制剂复合物+头孢类的多重耐药模式有18种。176株菌共检出43种ST型别，检出率前三的ST型别分别为ST11、ST34和ST19，检出率分别为27.27%、10.80%和7.95%。【结论】 苏州市沙门氏菌的血清型和ST型别种类多，血清型以肠炎沙门氏菌和鼠伤寒沙门氏菌为优势型别，ST型以ST11为优势型别。多重耐药现象严重，应加强监测。

Abstract:

[Background] Salmonella is a zoonotic pathogen and one of the most common pathogens causing infectious diarrhea in humans. [Objective] To analyze the serotypes, drug resistance, and multilocus sequence types of 176 Salmonella strains isolated in Suzhou, 2023. [Methods] The serotypes of the isolates were identified by the slide agglutination method. The drug resistance was tested by the micro-broth dilution method. The multilocus sequence typing (MLST) was performed by whole genome sequencing, and the sequencing results were compared with PubMLST to obtain the sequence types (STs) of the strains. [Results] A total of 42 serotypes belonging to 9 serogroups were identified for the 176 Salmonella isolates. The dominant serotypes were Salmonella enteritidis (26.70%) and Salmonella typhimurium (18.75%). The resistance rate of the 176 strains to ampicillin was the highest (60.23%), followed by that to streptomycin (47.16%). All the strains were sensitive to ceftazidime/avibactam, meropenem, ertapenem, and amikacin. The multidrug resistance (MDR) of the 176 strains reached a rate of 57.39%, with 51 patterns (including 18 patterns involving penicillins+ β-lactam/ β-lactam inhibitor complex+cephalosporins). The 176 strains presented 43 STs, among which ST11, ST34, and ST19 were the top three, with the detection rates of 27.27%, 10.80% and 7.95%, respectively. [Conclusion] The Salmonella strains in Suzhou present diverse serotypes and STs. The dominant serotypes are S. enteritidis and S. typhimurium, and the dominant ST is ST11. The MDR phenomenon is serious and thus surveillance should be strengthened.