New antibiotic resistance genes associated with CTX-M plasmids from uropathogenic Nigerian Klebsiella pneumoniae (original) (raw)

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 0)-Ib (aminoglycoside resistance) which included aac(6 0)-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 c...