Mamlouk Kelthoum, Boutiba-Ben Boubaker Ilhem, Gautier Valérie, Vimont Sophie, Picard Bertrand, Ben Redjeb Saida, Arlet Guillaume
Laboratoire Résistance aux Antibiotiques, Département de Microbiologie, Faculté de Medecine, Tunis, Tunisia.
J Clin Microbiol. 2006 Nov;44(11):4049-56. doi: 10.1128/JCM.01076-06. Epub 2006 Sep 6.
Sixty-two isolates of Enterobacteriaceae (35 Escherichia coli and 27 Klebsiella pneumoniae isolates) producing CTX-M-type beta-lactamases were collected between March 2000 and June 2003 in different wards of Charles Nicolle Hospital in Tunis (Tunisia). Sequencing identified the bla(CTX-M-15) determinant in 55 isolates and bla(CTX-M-16) in 7 isolates. The CTX-M-15-producing strains were isolated in several wards and consisted mainly of two successive clonal groups of E. coli and a major clonal group of K. pneumoniae. The second clonal group of E. coli belonged to phylogenetic group B2 and harbored more virulence factors than the first clonal group. Among the 22 transconjugants or electroporants obtained with selected E. coli and K. pneumoniae CTX-M-15-producing strains, a predominant plasmid restriction pattern was obtained with 17 isolates. The four CTX-M-16-producing strains of E. coli yielded the same pulsed-field gel electrophoresis (PFGE) pattern, while the three CTX-M-16-producing strains of K. pneumoniae yielded two different PFGE patterns. All of the CTX-M-16-producing isolates were recovered in the pediatric ward and had the same plasmid restriction pattern.
2000年3月至2003年6月期间,在突尼斯突尼斯市查尔斯·尼科勒医院的不同病房收集了62株产CTX-M型β-内酰胺酶的肠杆菌科细菌(35株大肠杆菌和27株肺炎克雷伯菌)。测序鉴定出55株中存在bla(CTX-M-15) 决定簇,7株中存在bla(CTX-M-16)。产CTX-M-15的菌株在多个病房被分离出来,主要由两个连续的大肠杆菌克隆群和一个主要的肺炎克雷伯菌克隆群组成。大肠杆菌的第二个克隆群属于系统发育组B2,比第一个克隆群携带更多的毒力因子。在用选定的产CTX-M-15的大肠杆菌和肺炎克雷伯菌菌株获得的22个转接合子或电穿孔子中,17个分离株获得了主要的质粒限制性图谱。4株产CTX-M-16的大肠杆菌菌株产生相同的脉冲场凝胶电泳(PFGE)图谱,而3株产CTX-M-16的肺炎克雷伯菌菌株产生两种不同的PFGE图谱。所有产CTX-M-16的分离株均在儿科病房分离得到,且具有相同的质粒限制性图谱。