Rossolini G M, D'Andrea M M, Mugnaioli C
Dipartimento di Biologia Molecolare, Sezione di Microbiologia, Università di Siena, Siena, Italy.
Clin Microbiol Infect. 2008 Jan;14 Suppl 1:33-41. doi: 10.1111/j.1469-0691.2007.01867.x.
CTX-M-type enzymes are a group of class A extended-spectrum beta-lactamases (ESBLs) that are rapidly spreading among Enterobacteriaceae worldwide. More that 50 allotypes are known, clustered into six sub-lineages. The CTX-M-encoding genes have been captured from the chromosome of Kluyvera spp. on conjugative plasmids that mediate their dissemination among pathogenic enterobacteria. CTX-M-type ESBLs exhibit powerful activity against cefotaxime and ceftriaxone but generally not against ceftazidime, which has important implications for laboratory detection. However, several CTX-M variants with enhanced ceftazidimase activity have been detected. The rapid and massive spread of CTX-M-type ESBLs is rapidly changing the ESBL epidemiology and, in some geographical areas, these enzymes are now the most prevalent ESBLs in Enterobacteriaceae.
CTX-M型酶是A类超广谱β-内酰胺酶（ESBLs）中的一组，正在全球范围内的肠杆菌科细菌中迅速传播。已知有50多种同种异型，分为六个亚谱系。编码CTX-M的基因已从克吕沃尔菌属的染色体上捕获到接合质粒上，这些质粒介导它们在致病性肠杆菌之间传播。CTX-M型ESBLs对头孢噻肟和头孢曲松表现出强大的活性，但通常对头孢他啶无活性，这对实验室检测具有重要意义。然而，已经检测到几种具有增强头孢他啶酶活性的CTX-M变体。CTX-M型ESBLs的迅速大量传播正在迅速改变ESBLs的流行病学，并且在一些地理区域，这些酶现在是肠杆菌科细菌中最普遍的ESBLs。
