Characteristics and drug resistance of non-O157 Shiga toxin-producing E. coli in animal feces, from Shandong Province
10.3760/cma.j.issn.0253-9624.2018.03.010
- VernacularTitle: 山东省动物粪便中非O157产志贺毒素大肠埃希菌菌株特征及耐药性分析
- Author:
Bin HU
1
;
Zengqiang KOU
;
Chunchun SHAO
;
Haiying YIN
;
Zongdong LIU
;
Xuehua XU
;
Ming FANG
;
Baoli CHEN
;
Changyin WEI
;
Guifeng LI
;
Zhenwang BI
Author Information
1. Shandong Provincial Center for Disease Control and Prevention, Ji'nan, Shandong 250014, China
- Publication Type:Journal Article
- Keywords:
Shiga-toxigenic escherichia coli;
Electrophoresis, gel, pulsed-field;
Strain characteristics;
Drug resistance monitoring
- From:
Chinese Journal of Preventive Medicine
2018;52(3):271-276
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To understand the infection status, characteristics and drug resistance of non-O157 Shiga toxin-producing E. coli (STEC) in animal feces in Shandong Province.
Methods:From 2015 to 2016, convient sampling method was used to collect 1 022 fresh feces of animals in Weishan county and Laizhou city, and 24 non-O157 STEC were isolated. The serotypes of non-O157 STEC strains were confirmed through serum agglutination test. The susceptibility was explored through the antimicrobial sensitivity experiments. ESBLs activity was confirmed by double-disc diffusion. PCR method was used to detect the resistance genes. PFGE typing was operated to assess the relatedness and variability of the strains. The multi-locus sequence typing (MLST) was adopted to get the allelic profile and ST sequence of strains. Analysis was made on the evolutionary relationship between different ST groups was made through CLC Sequence Viewer and Counting Express.
Results:A total of 24 non-O157 STEC were isolated from animal feces. 23 strains were from pig feces, and 1 strain was from cow feces, and the serotypes were more dispersed. All of the 24 strains carried stx2 genes. The highest resistance rate was sulfamethoxazole(22 strains), the mount of cotrimoxazole and nalidixic acid was 18 strains, chloramphenicol was 13 strains, tetracycline was 19, and there was a phenomenon of multiple drug resistance. The drug resistance spectrum was sulfamethoxazole tetracycline-compound novammin-naphthidine-chloramphenicol. All strains were sensitive to cefepime and imipenem. The ESBLs confirmatory test showed that 4 strains of non O157 STEC produced beta lactamase. PCR detected 7 resistance genes, and 4 tetracycline resistance genes (Tet A, Tet B, tetC and tetD) were detected. The beta lactamase resistance genes (blaSHV-1, bla CTX-M, bla TEM) were all negative. 24 strains were divided into 15 PFGE types, and their clustering results were more dispersed and no dominant PFGE type. There were 11 kinds of MLST types, most of them are ST540 and ST5133 types, each of which was 4 strains, and clustered into 1 MLST genomes.
Conclusion:The serotypes of non-O157 STEC in animal feces O157 STEC were dispersed, and the resistant rate to common antibiotic was high. MLST typing results presents obvious polymorphism. Surveillance and manage ment of these strains should be strengthened.
