CTX-M-15 extended-spectrum (beta)-lactamase from Nigerian Klebsiella pneumoniae.
J Antimicrob Chemother, 2006/1;57(1):24-30.
Soge OO[1], Queenan AM, Ojo KK, Adeniyi BA, Roberts MC
Affiliations
PMID: 16319181
Impact factor: 5.758
Abstract
objectives: In this study, extended-spectrum beta-lactamases (ESBLs) were characterized from 30 selected multidrug-resistant Klebsiella pneumoniae strains isolated from patients with community-acquired urinary tract infections from Southwest Nigeria.
methods: The beta-lactamases were phenotypically characterized using isoelectric focusing, genotypically characterized using PCR assays and hybridization of the PCR products. Two of the bla(CTX-M) genes were completely sequenced. The location of the CTX-M-type genes was determined using transformation, DNA-DNA hybridization, PCR assays and hybridization of the PCR products from the Escherichia coli transformants.
results: All 30 isolates produced at least one beta-lactamase. Seventeen of the isolates were resistant to cefotaxime, and had > or =100-fold reduction in susceptibility with cefotaxime plus clavulanic acid (4 mg/L), indicating the presence of an ESBL. The 17 isolates were shown to have bla(CTX-M) genes that were associated with large plasmids (> or =58 kb), which also carried a tetracycline resistance gene, tet(A), and various aminoglycoside resistance genes. Two CTX-M-type genes were sequenced and had amino acid sequences indistinguishable from previously sequenced CTX-M-15 beta-lactamases. The ISEcp1 element was located upstream of bla(CTX-M-15) in the same position as previously described. In addition, 23 of the isolates produced TEM beta-lactamases, 27 produced SHV beta-lactamases and four produced AmpC beta-lactamases.
conclusions: Thirty K. pneumoniae produced multiple beta-lactamases, with 57% producing CTX-M enzymes. This is the first characterization of CTX-M-15-positive K. pneumoniae in Western Africa.
MeSH terms
Anti-Bacterial Agents; Base Sequence; Community-Acquired Infections; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Escherichia coli; Female; Genes, Bacterial; Humans; In Situ Hybridization; Isoelectric Focusing; Klebsiella Infections; Klebsiella pneumoniae; Male; Microbial Sensitivity Tests; Molecular Sequence Data; Nigeria; Plasmids; Urinary Tract Infections; beta-Lactamases
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