Prevalence and characterization of extended-spectrum beta-lactamases in Klebsiella pneumoniae in Alg
July 3rd, 2008 | by admin |Prevalence and characterization of extended-spectrum beta-lactamases in Klebsiella pneumoniae in Algiers hospitals (Algeria).
AIM OF THE STUDY: To determine the prevalence and the diversity of extended-spectrum beta-lactamases (ESBLs) in 196 Klebsiella pneumoniae clinical isolates collected from three hospitals in Algiers. MATERIALS AND METHODS: Antibiograms were done on Mueller-Hinton agar plates with the disc-diffusion method and MICs were determined by agar-dilution method. Mating experiments were performed in agar medium. Plasmid DNA was extracted by the alcalin-lysis method. Total DNA was extracted with a Qiagen mini kit and screened for bla(TEM) and bla(CTX-M) genes by PCR. Linkage of bla(CTX-M) genes with insertion sequence ISEcp1B and class 1 integrons was investigated by PCR. PCR products were sequenced by the Sanger method. The epidemiological relationships between ESBL-producing K. pneumoniae isolates were analyzed by ERIC-PCR. RESULTS: Thirty-nine (19.9%) isolates were found to produce ESBLs belonging to CTX-M-1 group and TEM penicillinases (CTX-M-3, CTX-M-15 and TEM-1). ERIC-PCR analysis showed that the isolates are genetically unrelated. The bla(TEM) and bla(CTX-M) genes as well as aminoglycosides and sulfonamides resistance determinants were found located in self-transferable plasmids of approximately 85kb.The class 1 integrons and the insertion sequence ISEcp1B were present in the isolates and in their transconjugants. ISEcp1B was found genetically linked to the bla(CTX-M) genes and located 127bp upstream, with the presence of the V and W sequences. CONCLUSION: The study revealed a high rate of ESBL-producing K. pneumoniae in Algerian hospitals, resulting from horizontal dissemination of mobile bla(CTX-M) genes.
Messai Y, Iabadene H, Benhassine T, Alouache S, Tazir M, Gautier V, Arlet G, Bakour R.
Laboratoire de biologie cellulaire et moléculaire, faculté des sciences biologiques, université des sciences et de la technologie Houari-Boumédiène, B.P. 32 El-Alia, Bab-Ezzouar 16111, Alger, Algeria.