TEM Derivative-Producing Enterobacter aerogenes Strains: Dissemination of a Prevalent Clone

TEM-24 (CAZ-6) extended-spectrum β-lactamase (ESBL) was detected in 1988 in Clermont-Ferrand, France, in Klebsiella pneumoniae (bla(TEM-24)) and Enterobacter aerogenes (bla(TEM-24b)), and since 1994, a TEM-24-producing E. aerogenes clonal strain has been observed elsewhere in the country. To determine if the spread of this clonal strain was restricted to TEM-24-producing E. aerogenes strains, 84 E. aerogenes strains (non-TEM/SHV-producing strains, TEM-1- or -2-producing strains, and different ESBL-producing strains), isolated from 1988 to 1999 in Clermont-Ferrand (n = 59) and in 11 other French hospitals in 1998 (n = 25), were studied. A clonal strain was found for TEM-24- but also for TEM-3- and TEM-1- or 2-producing isolates. This study shows that there is a clonal strain dependent on acquisition of the TEM-type enzyme (TEM-24 and other TEM types).

1988年，法国克莱蒙费朗地区从肺炎克雷伯菌（Klebsiella pneumoniae，bla(TEM-24)）和产气肠杆菌（Enterobacter aerogenes，bla(TEM-24b)）中检出TEM-24（CAZ-6）型超广谱β-内酰胺酶（extended-spectrum β-lactamase，ESBL）。自1994年起，法国其他地区陆续发现产TEM-24型酶的产气肠杆菌克隆株。为明确该克隆株的传播范围是否仅局限于产TEM-24型酶的产气肠杆菌菌株，研究人员对84株产气肠杆菌展开研究，这些菌株涵盖非产TEM/SHV型酶菌株、产TEM-1或TEM-2型酶菌株以及不同类型的产ESBL菌株，其中1988年至1999年间从克莱蒙费朗分离的有59株，1998年从法国其余11家医院分离的有25株。研究发现，除产TEM-24型酶的分离株外，产TEM-3型及产TEM-1/2型酶的分离株也存在对应的克隆株。本研究表明，存在一类依赖于获得TEM型酶（包括TEM-24及其他TEM亚型）的克隆菌株。