婴幼儿感染猪霍乱沙门菌耐药基因特点及同源性分析

目的研究致婴幼儿败血症猪霍乱沙门菌的耐药基因特点及同源性。方法16株猪霍乱沙门菌．采用K—B纸片扩散法检测抗菌药物的耐药性，同时用PCR法及DNA测序法对其进行β-内酰胺酶类耐药基因检测；PFGE法测定同源性。结果对氨苄西林耐药的13株猪霍乱沙门菌经PCR扩增后并测序为bl岫。16株猪霍乱沙门菌经PFGE分型，可分为5个PFGE型，其中A型是最主要的克隆（12／16）。13株blTEM-1．基因阳性菌株分别为A型11株，B型1株，D型1株。结论产TEM-1割β-内酰胺酶是本地区猪霍乱沙门菌对氨苄西林耐药的主要机制，PFGE分型方法对猪霍乱沙门菌分型能力较好。克隆性传播为猪霍乱沙门菌的主要传播途径．同一PFGE型菌株的耐药谱非常接近。

Analysis of drug-resistant genes and homology of Salmonella choleraesuis in children.

Objective To investigate drug-resistant genes and homology of Salmonella choleraesuis isolates from the blood of children with septicemia. Methods A total of 16 strains of Salmonella choleraesuis were collected from children with septicemia. Antimicrobial susceptibility was determined by K-B disk,PCR and DNA sequencing were used for detecting β-1actamases and quinolones genes. Their homology was identified by PFGE. Results Thirteen strains of ampicillin resistant Salmonella choleraesuis were identified by PCR amplifying and DNA Sequencing and their drug-resistant gene yeas blaTEM-1. 16 strains of Salmonella cholcraesuis were classified into 9 PFGE types. A type was the most important clone （12/16）. Thirteen strains with blaTEU-I gene in- clude A type（11 strains）, B type（l strains） and D type（1 strains）. Conclusion For Salmonella choleraesuis, β-1actamases based on TEM-1 gene is the primary ampicillin resistant mechanism. PFGE is a proper method for Salmonella choleraesuis classification and the strains from same PFGE type have similar drug resistance spectrum. And clonal spread is the main transmission route for Salmonella cholemesuis.