1831株宋内志贺菌耐药性调查及其产ESBLs的研究

Drug resistance and ESBLs producing in 1831 Shigella sonnei strains

目的了解分离自腹泻患者的1831株宋内志贺菌的流行趋势及耐药情况,探讨宋内志贺菌多重耐药机制。方法采用志贺菌及沙门菌琼脂培养基培养及K-B法检测14种抗生素的耐药率。多重耐药菌用纸片确认试验检测产超广谱β内酰胺酶(extended-spectrum β-lactamases,ESBLs),改良三维试验检测ESBLs和AmpCβ内酰胺酶(AmpC β-lactamase,AmpC酶)。结果1831株宋内志贺菌感染腹泻患者中,男女比例为1.25∶1。高发季节为7～9月。1～20岁发病人数占总发病人数的71.0%。宋内志贺菌对复方磺胺甲噁唑、氨苄西林和头孢曲松的耐药率较高,分别达87.7%、23.0%和9.5%,且增高趋势明显;对氟喹诺酮类,头孢吡肟、头孢美唑、氯霉素、磷霉素和庆大霉素的耐药率较低,明显低于头孢曲松、头孢噻肟(P<0.05)。43株多重耐药菌均为ESBLs阳性株,未发现产AmpC酶株。结论在北京地区,宋内志贺菌感染腹泻患者发病年龄以青少年为主。其在志贺菌属感染的比例中有增高的趋势,对头孢曲松、头孢噻肟、复方磺胺甲噁唑、氨苄西林的耐药率较高且有上升趋势。宋内志贺菌耐头孢菌素者以产ESBLs为主。

Objective To investigate the trend of prevalence and drug resistance of the 1 831 Sbigella sonnei strains isolated from diarrhea patients in our hospital, and explore the mechanism of muhidrug resistance of Shigella sonnei strains. Methods The Sbigella and Sahnonella （SS） agar for culture and Kirby-Bauer disk diffusion method were adopted to determine the drug-resistant rates to 14 antibioties. The confirmatory test was used to detect extended-spectrum β-1actamases （ESBLs） of multidrug-resistant Sbigella sonnei. The modi-fied three-dimensional extract test was used to detect both ESBLs and AmpC β-lactamase （AmpC）. Results The ratio of males to females was 1.25：1 among diarrhea patients from whom 1 831 ShigeHa sonnei strains were isolated. High incidence occurred from July to September. Patients of 1-20 years old accounted for 71.0% of all the patients. The resistant rates of Sbigella sonnei to sulfamethoxazole/trimethoprim, ampicillin and ceftriaxone were 87.7%, 23.0% and 9.5%, respectively, with a significant increasing tendency. The resistant rates of Shigella sonnei to fluoroquinolones, cefepimc, cefmetazole, chloromycetin, fosfomycin and gentamycin were significantly lower than those of ceftriaxone and cefotaxime （P〈0.05）. All the 43 multidrug resistant strains were ESBLs positive, and no strains were found to produce AmpC enzyme. Conclusions In Beijing, most of the patients infected with Sbigella sonnei are teenagers and the incident rate is rising. The resistant rates of ceftriaxone, cefotaxime, sulfamethoxazol/trimethoprim and ampicillin are higher, with an increasing tendency. Shigella sonnei strains resistant to cephalosporins mainly produce ESBLs.