1. New antibiotic resistance genes associated with CTX-M plasmids from uropathogenic Nigerian Klebsiella pneumoniae.
- Author
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Soge, Olusegun O., Adeniyi, Bolanle A., and Roberts, Marilyn C.
- Abstract
Objectives: To determine antibiotic resistance genes associated with 17 Nigerian CTX-M-positive Klebsiella pneumoniae plasmids from patients with community-acquired urinary tract infections.Methods: The size and restriction patterns of the plasmids were determined, and antibiotic resistance genes were identified using DNA–DNA hybridization, PCR assays, hybridization of PCR products with internal probes, and sequencing.Results: All CTX-M plasmids were large (58–320 kb) and carried the following genes: aac(6′)-Ib (aminoglycoside resistance) which included aac(6′)-Ib-cr (aminoglycoside-fluoroquinolone resistance), aadA2 (aminoglycoside resistance), erm(B) (macrolide-lincosamide-streptogramin B resistance), blaTEM-1 (ampicillin resistance), tet(A) (tetracycline resistance), sul1 (sulphonamide resistance), dfr (trimethoprim resistance) and intI1, an integrase associated with class 1 integrons. Eleven (65%) plasmids carried an mph(A) gene (macrolide resistance), seven (41%) plasmids carried a qnrB1 gene (low-level quinolone resistance) and four (24%) plasmids carried multiple cat genes (chloramphenicol resistance). catA2, catA3 and qnrB1 genes and a 6 kb PstI fragment, carrying the blaCTX-M gene, were sequenced.Conclusions: This is the first description of catA2 and catA3 genes in Klebsiella spp. and the first description of the erm(B) and floR genes associated with a CTX-M plasmid. This is also the first report of qnrB1 and aac(6′)-Ib-cr in isolates from Africa and the first report of these two genes on the same plasmid. [ABSTRACT FROM PUBLISHER]
- Published
- 2006
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