title: Genetic characterisation of CTX-M-15-producing Klebsiella pneumoniae and Escherichia coli strains isolated from stem cell transplant patients in Tunisia.
abstract: Characterisation of extended-spectrum beta-lactamase (ESBL) genes and their genetic environments as well as the presence of integrons were analysed in nine Klebsiella pneumoniae and two Escherichia coli ESBL-positive isolates recovered in the Centre of Bone Marrow Transplantation of Tunisia. All strains harboured the bla(CTX-M-15) gene and presented minimum inhibitory concentrations for cefotaxime and ceftazidime of 256-1024 mg L(-1) and 16-512 mg L(-1), respectively, and eight of them showed different pulsed-field gel electrophoresis patterns. The bla(OXA-1) and bla(TEM-1) genes were detected in eight and ten strains, respectively. In addition, bla(SHV-1), bla(SHV-11) and bla(SHV-27) were found in six, one and one K. pneumoniae strains, respectively. The new variant bla(SHV-103) was characterised in one K. pneumoniae strain. The intI1 gene was detected in eight K. pneumoniae strains and the dfrA5+ereA2 and aadA gene cassettes were found in one and five strains, respectively. All strains harboured a 70 kb plasmid, and its transference in addition to bla(CTX-M-15), bla(TEM-1b) and bla(OXA-1) genes was demonstrated from three K. pneumoniae to E. coli. ISEcp1 and orf477 were located upstream and downstream, respectively, of the bla(CTX-M-15) gene in 10 strains. The occurrence of the bla(CTX-M-15) gene in unrelated strains might have originated from the dissemination of mobile genetic elements in which ISEcp1 may have played an important role.
authors.affiliation: Laboratory of the National Bone Marrow Transplantation Centre, Bab Saadoun, Tunis, Tunisia.
authors.forename: Mohamed Salah
authors.initials: MS
authors.lastname: Abbassi
authors.forename: Carmen
authors.initials: C
authors.lastname: Torres
authors.forename: Wafa
authors.initials: W
authors.lastname: Achour
authors.forename: Laura
authors.initials: L
authors.lastname: Vinué
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Sáenz
authors.forename: Daniela
authors.initials: D
authors.lastname: Costa
authors.forename: Ons
authors.initials: O
authors.lastname: Bouchami
authors.forename: Assia
authors.initials: A
authors.lastname: Ben Hassen
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002439:Cefotaxime / Q000494:pharmacology; D002442:Ceftazidime / Q000494:pharmacology; D018550:Cephalosporin Resistance; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology; D006760:Hospitalization; D006801:Humans; D007710:Klebsiella Infections / Q000453:epidemiology / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D010957:Plasmids; D033581:Stem Cell Transplantation / Q000009:adverse effects*; D014416:Tunisia / Q000453:epidemiology; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D002442:Ceftazidime; C473109:beta-lactamase CTX-M-15; D001618:beta-Lactamases; D002439:Cefotaxime