E. coli is among the most prevalent causes of hospital-acquired and community-acquired bacterial infections and their resistances to antimicrobial agents have become a serious concern for healthcare providers [5]. Phylogenetic analyses have classified E. coli into four main phylogenetic groups (A, B1, B2, and D). Commensal isolates belong mainly to A and B1 groups whereas virulent extra-intestinal pathogenic
E. coli (ExPEC) are essentially from the B2 and D groups [12, 13]. ExPEC harbor numerous virulence factors including α-hemolysin, cytotoxic necrotizing factor, adhesins and iron acquisition systems [12]. The spread of bla CTX-M-15 has been mainly associated with the dissemination of a particular clone of E. coli ST131 belonging to phylogenetic SAHA HDAC mouse group B2 [14, 15]. Recently, an E. coli clone O25 ST131, producing CTX-M-15, with high virulence potential and belonging to the B2 group, has been reported and represent a
major public health problem [14, 15]. Many reports have documented the emergence of ESBL-producing Enterobacteriaceae[16–18]. In Antananarivo, ESBLs were first detected in 2005 from UTI in 9.7% of isolated Enterobacteriaceae[19]. In 2006, outbreaks of CTX-M-15 and SHV-2-producing K. pneumoniae isolates have been described in two pediatric units [20]. More recently, 21.3% of clinical isolates from patients in surgery and intensive care units [21] and 21.2% of intestinal carriage isolates from children hospitalized in a pediatric department of a large teaching hospital [22] were ESBL-producers. For 49 BTK inhibitor multidrug-resistant Enterobacteriaceae isolates from Antananarivo, we characterized: i) the genes encoding the ESBLs; ii) the drug resistance genes associated with the ESBL genes; iii) gene cassettes present in the isolates; and iv) the plasmid incompatibility groups of the isolates. We also
determined the phylogenetic groups and virulence factors of the E. coli isolates. Methods Ethical clearance The study Branched chain aminotransferase protocols were approved by the National Ethics Committee of Madagascar. Written informed consents were obtained from all patients and at least one parent of each child before enrollment. Patients Between September 2006 and December 2007, a total of 909 non-duplicate bacterial isolates were obtained from 909 patients. 830 patients were recruited from several wards in four hospitals in Antananarivo, Madagascar (two national university teaching hospitals: Joseph Ravoahangy Andrianavalona Hospital and Befelatanana Hospital; a military hospital: Soavinandriana Hospital; and a pediatric hospital: Tsaralalana Hospital) and 79 patients referred to the Pasteur Institute Medical Laboratory in Antananarivo. Laboratory methods Various clinical specimens (including blood-culture, urine, pus, sputum and CSF) were collected and submitted for bacterial analysis at the Pasteur Institute Medical Laboratory in Antananarivo.