International Journal of Antimicrobial Agents 27 (2006) 545–548 First description of CTX-M -lactamase-producing clinical Escherichia coli isolates from Egypt Mohamed Hamed Mohamed Al-Agamy a , Mohamed Seif El-Din Ashour a , Irith Wiegand b,∗ a Department of Microbiology and Immunology, Faculty of Pharmacy, Al-Azhar University, Nasr City, Cairo, Egypt b Pharmaceutical Microbiology, University of Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany Received 2 November 2005; accepted 8 January 2006 Abstract We studied the presence of -lactamases with an extended spectrum of activity in clinical Escherichia coli isolates from Cairo, Egypt. Forty-six E. coli isolates were collected from patients with urinary tract infections at a university hospital in 2001. Phenotypic characterisation identified a very high extended-spectrum -lactamase (ESBL) rate of 60.9%. Pulsed-field gel electrophoresis and plasmid profiles revealed eight different clonal groups. All ESBL producers were polymerase chain reaction-positive for bla TEM and bla CTX-M genes. Within the CTX-M family, three different enzymes, CTX-M-14, CTX-M-15 and CTX-M-27, were found. The ESBL producers carried multiple plasmids and further plasmid-encoded resistances. In several strains, genes for up to six aminoglycoside-modifying enzymes were detected. A linkage to fluoroquinolone resistance was not observed. This study confirms the high rate of ESBLs in Egypt and further demonstrates the worldwide spread of genes coding for CTX-M enzymes in clinical isolates. © 2006 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved. Keywords: Egypt; Escherichia coli; -Lactamase; CTX-M; Multiresistance 1. Introduction Nosocomial pathogens with resistance to -lactams owing to plasmid-encoded -lactamases are a major global problem. Broad-spectrum -lactamases such as TEM-1, and to a lesser extent TEM-2 and SHV-1, are the most prevalent secondary -lactamases among clinical isolates of Enterobacteriaceae worldwide [1]. It has been known since 1983 that mutations in broad-spectrum -lactamase genes can lead to an extended- spectrum phenotype. Such extended-spectrum -lactamases (ESBLs) are then capable of hydrolysing oxyimino-- lactams as well as older penicillins and cephalosporins [2]. In addition to the rapidly growing number of TEM and SHV variants of ESBLs (http://www.lahey.org/Studies/), other non-TEM and -SHV enzymes such as GES/IBC, VEB, PER and CTX-M are disseminating worldwide. The CTX-M enzymes, originating from chromosomal -lactamase genes ∗ Corresponding author. Tel.: +49 228 735 347; fax: +49 228 735 267. E-mail address: Wiegand@uni-bonn.de (I. Wiegand). in Kluyvera spp., form a rapidly growing family of currently over 50 enzymes [3]. CTX-M -lactamases now play a major role and are the most common ESBLs in several countries such as Argentina, China and the UK [4]. Little is known about the types of -lactamases occur- ring in Egypt. However, two studies point to a very high proportion of ESBLs in Escherichia coli. El Kholy et al. pre- sented resistance data of clinical isolates from five Egyptian hospitals from 1999 to 2000 [5]. Thirty-eight percent of the E. coli (n = 50) strains were resistant to ceftazidime, point- ing to ESBLs and/or AmpC enzyme production. An even higher ESBL proportion in E. coli (n = 14) of 42.9% was determined in a recent study using National Committee for Clinical Laboratory Standards (NCCLS) ESBL screening cri- teria [6]. However, -lactamases were not characterised in either study. The aim of this study was to determine the molecular basis of resistance to extended-spectrum cephalosporins in E. coli isolates from urinary tract infections (UTIs) from patients at a University Hospital in Cairo. 0924-8579/$ – see front matter © 2006 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved. doi:10.1016/j.ijantimicag.2006.01.007