2015—2017年中山市某医院沙门菌的药敏分析及肠毒素基因检测

Drug susceptibility analysis and enterotoxin gene detection of Salmonella in a hospital from 2015 to 2017 in Zhongshan

目的研究中山市西北部区域沙门菌感染患者的流行病学特征、耐药特点及其相关肠毒素基因型。方法 2015年1月—2017年12月,我院从4019例腹泻患者的粪便标本中共分离出沙门菌108株,进行血清分型及药物敏感试验,同时采用PCR方法检测其肠毒素基因(spvA、spvB、rck)。结果 108株沙门菌可分为17个血清型,以鼠伤寒沙门菌和斯坦利沙门菌为主,分别占42.6%(46/108)和15.7%(17/108),2015年分别检出伤寒沙门菌、乙型副伤寒沙门菌和丙型副伤寒沙门菌各一株;108株沙门菌对氨苄西林(61.11%)和氨苄西林/舒巴坦(49.07%)耐药率最高,未发现对亚胺培南及哌拉西林/三唑巴坦的耐药菌株;在108株沙门菌中,所有菌株均含有spvA基因,34株为spvB阳性,28株为rck阳性,spvB基因阳性患者其高热、便血的比率显著高于spvB阴性患者(χ~2=4.185, P<0.05;χ~2=6.13, P<0.05);rck基因阳性患者其高热、便血的比率显著高于rck阴性患者(χ~2=5.274, P<0.05,χ~2=8.887,P<0.05)。结论本地区沙门菌感染患者以鼠伤寒沙门菌和斯坦利沙门菌为主,高发季节集中在夏秋两季,沙门菌株耐药率较高。沙门菌感染患者高热及便血的发生率与spvB基因、rck基因的检出具有明显相关性。

Objective To investigate the epidemiological characteristics, drug resistance characteristics, and enterotoxin genotypes of patients infected with Salmonella in the northwestern part of Zhongshan city. Methods From January 2015 to December 2017, 108 strains of Salmonella were isolated from fecal specimens for 4,019 diarrhea patients. The Salmonella serotyping and antimicrobial susceptibility testing were conducted. At the same time, the enterotoxin genes (spvA, spvB, and rck) were detected using PCR. Results The 108 strains of Salmonella were divided into 17 serotypes, of which Salmonella typhimurium and Salmonella stanley were dominant, accounting for 42.6% (46/108) and 15.7% (17/108) respectively. A strain of Salmonella typhi, Salmonella paratyphi B and Salmonella paratyphi C were detected in 2015. The 108 strains of Salmonella had the highest resistance rates to ampicillin (61.11%) and ampicillin/sulbactam (49.07%), and no resistant strains to imipenem and piperacillin/tazobactam were found. Among the 108 strains of Salmonella, all strains contained the spvA gene, 34 strains were positive for spvB, and 28 strains were rck positive. The spvB gene positive patients had significantly higher rates of fever and hematochezia than spvB negative patients (χ^2=4.185, P<0.05, χ^2=6.13, P<0.05). The rck gene positive patients had significantly higher rates of fever and hematochezia than patients with rck negative (χ^2=5.274, P<0.05, χ^2=8.887, P<0.05). Conclusion Salmonella typhimurium and Salmonella stanley are the main serotypes in this area, and such infections usually peak in summer and autumn seasons. Salmonella strains have high resistance rates. The incidence of fever and hematochezia of patients with Salmonella infections was significantly correlated with the detection of the spvB gene and the rck gene.