Characterization and molecular epidemiology of extended spectrum beta-lactamase producing Enterobacter cloacae isolated from a Tunisian hospital

• Published in: Microbial drug resistance (Larchmont, N.Y.) Vol. 18; no. 1; p. 59
• Main Authors: Hammami, Samia, Boutiba-Ben Boubaker, Ilhem, Saidani, Mabrouka, Lakhal, Emna, Ben Hassen, Aymen, Kamoun, Aouatef, Ghozzi, Rafiaa, Slim, Amin, Ben Redjeb, Saida
• Format: Journal Article
• Language: English
• Published: United States 01-02-2012
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents - pharmacology; Bacterial Proteins - genetics; beta-Lactamases - genetics; Carbapenems - pharmacology; Child; Child, Preschool; Drug Resistance, Multiple, Bacterial; Electrophoresis, Gel, Pulsed-Field; Enterobacter cloacae - drug effects; Enterobacter cloacae - genetics; Enterobacter cloacae - isolation & purification; Enterobacteriaceae Infections - drug therapy; Enterobacteriaceae Infections - epidemiology; Enterobacteriaceae Infections - microbiology; Female; Humans; Infant; Male; Middle Aged; Molecular Epidemiology; Phylogeny; Plasmids; Sequence Analysis, DNA; Tunisia - epidemiology; Tunisia
• ISSN: 1931-8448
• DOI: 10.1089/mdr.2011.0074

In 2009, out of the 66 nonrepetitive Enterobacter cloacae collected at Charles Nicolle hospital in Tunisia, 44 were extended spectrum β-lactamase (ESBL) producers. The aim of the current study was to detect and characterize the genes encoding the ESBLs including blaTEM, blaSHV, and blaCTX-M groups by polymerase chain reaction and sequencing. Pulsed-field gel electrophoresis (PFGE) analysis was used to determine the genetic relatedness between isolates. All strains were susceptible to carbapenems. They were resistant to fluoroquinolones, gentamicin, tobramycin, and trimethoprim+sulfamethoxazole but variably resistant to netilmicin, amikacin, and tetracyclines. Sequence analysis of the polymerase chain reaction products revealed the presence of blaCTX-M-15 (39 strains), blaSHV-12 (6 strains), and blaSHV-27 (1 strain). The coexistence of two ESBLs was observed in two isolates harboring, respectively, SHV-12+CTX-M-15 and SHV-27+CTX-M-15. PFGE revealed 36 unrelated profiles. Diffusion of E. cloacae producing CTX-M-15 ESBL in our hospital is the consequence of dissemination of identical or related plasmids harboring the CTX-M-15 gene.