安徽省149例腹泻病例中的分离沙门菌耐药谱及耐药基因分析

Analysis of drug resistance pattern and genes of Salmonella.spp isolated from human infections in Anhui Province

目的分析安徽省腹泻病例粪便及肛拭子标本中所分离沙门菌的耐药谱及耐药基因型。方法选取分离自2017年4—10月安徽省腹泻病例粪便及肛拭子标本的149株沙门菌,采用玻片凝集法鉴定沙门菌血清型,采用微量肉汤稀释法测定所有菌株对14种抗生素药物的敏感性。选取其中耐头孢类抗生素的菌株,采用多重PCR方法对β‐内酰胺酶编码基因blaTEM、blaSHⅤ、blaOXA?1、blaOXA?2、blaPER、blaCMY、blaCTX?M,以及黏菌素耐药基因mcr?1和mcr?2进行检测。结果腹泻病例年龄M(P25,P75)为5.0(1.1,38.5)岁,男性为92例,≤12岁病例占54.4%(81例)。149株沙门菌中,105株对除亚胺培南以外的其他13种抗生素均具有不同程度的耐药性,其中,对氨苄西林的耐药率最高,为55.0%(82株),53.0%(79株)的菌株同时对≥3类抗生素耐药(多重耐药),主要为鼠伤寒沙门菌(83.6%,46/55)和肠炎沙门菌(71.4%,20/28)。共检出53种耐药谱,最常见耐药谱为氨苄西林‐氨苄西林/舒巴坦‐四环素‐氯霉素‐头孢唑啉‐甲氧苄啶/磺胺甲噁唑,共10株。60株耐头孢类抗生素菌株中,45株携带blaTEM?1基因的菌株,其中6株同时携带blaCTX?M?14基因,3株同时携带blaCTX?M?65基因;32株单独携带blaTEM?1耐药基因,且均对氨苄西林产生耐药性,其中31株对头孢唑啉产生了耐药性;2株未检出耐药基因。检出1株携带mcr?1基因的多重耐药菌。结论安徽省沙门菌对氨苄西林耐药现象较严重,且多重耐药菌株较多;blaTEM?1型基因是检出的主要耐药基因;检出mcr?1基因提示应关注安徽省沙门菌多黏菌素耐药情况。

Objective To investigate the drug resistance pattern and drug resistance genotypes of Salmonella.spp isolated from fecal specimens and anal swabs of diarrhea cases in Anhui Province.Methods The 149 strains of Salmonella.spp isolated from feces and anal swabs of diarrhea cases in Anhui Province from April to October 2017 were selected.The serotypes of Salmonella.spp were identified by slide agglutination.The susceptibility of all strains to 14 antibiotics were determined by micro‐broth dilution method.Sixty of the cephalosporin‐resistant antibiotics were selected.Theβ‐lactamase encoding genes blaTEM,blaSHV,blaOXA?1,blaOXA?2,blaPER,blaCMY,blaCTX?M,and colistin resistance genes mcr?1 and mcr?2 were performed using the multi‐PCR method.Results Of the 149 diarrhea cases,the median(P25,P75)of the age was 5.0(1.1,38.5).The 92 of them were male and 54.4%were children.Of the 149 strains of Salmonella.spp,105 strains had different degrees of resistance to 13 antibiotics other than imipenem.The resistance rate of ampicillin was 55.0%(82/149),which was the highest.53.0%strains(79 strains)were multidrug resistant,main of which were Salmonella typhimurium and Salmonella enteritidis.A total of 53 resistance patterns were detected,and 10 strains were resistant to ampicillin‐ampicillin/sulbactam‐tetracycline‐chloramphenicol‐cefazolin‐trimethoprim/sulfamethoxazole,which was the most common resistance pattern.Among the 60 cephalosporin resistant strains,45 strains carried blaTEM?1,6 of which also carried blaCTX?M?14 and 3 of which also carried blaCTX?M?65.All the 32 strains carried only blaTEM?1 show resistance to ampicillin and 31 of them show resistance to cefazolin.There were 2 strains showing negative results of gene detection.mcr?1 was detected in a multidrug resistant strain.Conclusion The resistance of Salmonella.spp to ampicillin shows a serious situation in this region,and there were a number of multidrug resistant strains.The blaTEM?1 was the major drug resistance gene detected in this research.Detection of the mcr?1 suggests the emergence of surveillance to colistin resistance of Salmonella.spp in this area.