2012—2015年北京市西城区单核细胞增生李斯特菌多位点序列分型及耐药研究

Study on the homologous and antibiotic susceptibility of foodborne Listeria monocytogens in a district of Beijing

目的探讨单核细胞增生李斯特菌多位点序列分型(MLST)与耐药性的关联性,确定某些具有高致病性潜能的流行克隆株的存在。方法采用Kirby-Bauer(K-B)纸片扩散法和E-test药敏试条法对14种抗生素进行药物敏感性试验,以MLST技术对50株菌株进行基因分型。结果单核细胞增生李斯特菌耐药率为22.00%(11/50),并出现多重耐药株。50株单核细胞增生李斯特菌MLST分析共获得12个型别,以ST9和ST121为优势型别。结论特定ST型别在食品生产过程中存在特定菌株之间的传递,人源性和食源性单核细胞增生李斯特菌中均发现耐药株,可能存在耐药基因的传递,应加强对具有潜在致病性的ST型别的监测力度。

Objective To investigate the association between the multilocus sequence tying（ MLST） of Listeria monocytogenes and its antibiotic susceptibility,and to determine the presence of some clonal strains with high pathogenic potential. Methods Susceptibility tests were performed through the Kirby-Bauer（ K-B） method and E-test method with fourteen antibiotics; and then 50 Listeria monocytogenes strains were genotyped by MLST. Results The antibiotic resistant rate of Listeria monocytogenes was 22. 00%（ 11/50）,and multi-resistant strains appeared during the tests. The 50 Listeria monocytogenes strains were divided into 12 types based on MLST typing with ST9 and ST121 was being the dominant types.Conclusion Specific STs could transfer to particular strains during food production processes. The resistant strains were found in both foodborne and human source Listeria monocytogenes. There was a possibility of the transmission of antibioticresistant genes,thus the monitoring of potentially pathogenic ST-type was quite important to reduce Listeria monocytogenes.