Laboratory of Microbiology, University Hospital Center (CHU) of Habib Bourguiba, Sfax, Tunisia.
Microb Drug Resist. 2009 Dec;15(4):279-86. doi: 10.1089/mdr.2009.0035.
Eighty-four isolates of Salmonella enterica serovar Livingstone were collected from patients hospitalized in a pediatric ward in Sfax Hospital (South Tunisia). These isolates were responsible for two nosocomial outbreaks in 2000 and 2002. Twenty-eight clinical isolates of S. enterica serovar Livingstone were also obtained in two other Tunisian hospitals in Monastir (Central Tunisia) and Tunis (North Tunisia), respectively, in 2002 and 2003. Pulsed-field gel electrophoresis yielded that these isolates were closely related. Antimicrobial susceptibility testing showed a particular beta-lactam resistance phenotype, suggestive of the presence of an AmpC-type enzyme in 111 of the 112 clinical isolates. bla(ACC-1) was characterized by polymerase chain reaction (PCR) and sequence analysis in the 111 isolates. TEM-1 was characterized in all strains and SHV-2a in only two strains. The genetic organization of bla(ACC-1) was determined by PCR mapping and sequencing. The plasmid-borne bla(ACC-1) gene mapped immediately downstream from ISEcp1. This ISEcp1 insertion sequence was itself disrupted by IS26 insertion sequences. A supplementary deletion of 13 bp was observed in ISEcp1 upstream IS26, in all isolates from Tunis, except one. PCR analysis and sequencing also revealed the presence of tnpR, bla(SCO-1), gdha, IS1353, and TniB Delta 1.
84 株肠炎沙门氏菌利文斯通血清型分离株从斯法克斯医院儿科病房住院患者中收集。这些分离株导致了 2000 年和 2002 年的两次医院感染暴发。2002 年和 2003 年，在突尼斯的莫纳斯提尔（中部突尼斯）和突尼斯（北部突尼斯）的另外两家医院也获得了 28 株肠炎沙门氏菌利文斯通血清型临床分离株。脉冲场凝胶电泳显示这些分离株密切相关。抗菌药物敏感性试验显示出一种特殊的β-内酰胺耐药表型，提示 112 株临床分离株中有 111 株存在 AmpC 型酶。bla(ACC-1)通过聚合酶链反应（PCR）和序列分析在 111 株分离株中得到鉴定。TEM-1 在所有菌株中均得到鉴定，SHV-2a 仅在 2 株中得到鉴定。bla(ACC-1)的遗传结构通过 PCR 图谱和测序确定。质粒携带的 bla(ACC-1)基因紧邻 ISEcp1 下游定位。该 ISEcp1 插入序列本身被 IS26 插入序列破坏。在突尼斯的所有分离株中，除了一个，ISEcp1 上游 IS26 中观察到 13bp 的额外缺失。PCR 分析和测序还揭示了 tnpR、bla(SCO-1)、gdha、IS1353 和 TniB Delta 1 的存在。
