ĐẶC ĐIỂM KHÁNG KHÁNG SINH VÀ ĐẶC ĐIỂM DI TRUYỀN CỦA VI KHUẨN KHÁNG COLISTIN PHÂN LẬP TỪ THỊT GÀ, THỊT LỢN BÁN LẺ TẠI THÁI BÌNH

Abstract

The study was conducted to evaluate the antibiotic resistant and genetic characteristics of colistin-resistant Gram-negative bacteria isolated from retail chicken and pork in Thai Binh during the period 2018 - 2019. Forty-eight colistin-resistant Gram-negative strains (minimum inhibitory concentration MIC ≥ 4 mg/L) were evaluated for antibiotic sensitivity by diffusion disk method, detection of mcr genes by multiplex PCR and genetic relationship was also analysed by pulsed-field gel electrophoresis (PFGE) method. The results showed that colistin-resistant Gram-negative bacteria had relatively high rates of resistance to several antibiotics such as ampicillin, chloramphenicol, tetracycline, sulfamethoxazole - trimethoprim, nalidixic acid, but were still sensitive to fosfomycin, meropenem, ceftazidime and cefoxitin. The rate of multidrug resistance in colistin-resistant Gram-negative bacteria was 72.9%. The results also showed that 21 out of 48 strains (43.8%) carried the mcr-1 gene and no genes from mcr-2 to mcr-5 were detected. The proportion of chicken and pork samples contaminated with Gram-negative bacteria carrying the mcr-1 gene was 73.3% and 33.3%, respectively. The study results indicated that Gram-negative bacteria carrying mcr-1 gene frequently contaminated in retail chicken and pork in Thai Binh. Therefore, appropriate interventions should be implemented to prevent the emergence and spread of colistin-resistant Gram-negative bacteria in food, livestock and humans.