The emergence of carbapenem resistance in ESBL-producing Escherirchia coli O25B-ST131 strain from community acquired infection in Kuwait

Results The isolate was confirmed as E. coli O25b-sequence type (ST) 131 clone of B2 phylogenetic group. The isolate was resistant to all antibiotics tested except sulfamethoxazole, trimethoprim and nitrofurantoin and Etest confirmed that it is highly resistant to meropenem, imipenem, ciprofloxacin, cefotaxime and ceftazidime with MIC values of >16 mg/l, 32 mg/l, >64 mg/l, 32 mg/l & >32mg/l respectively. PCR detected the expected sizes of the amplified resistance genes, and DNA sequencing confirmed that TEM-1, the novel SHV-122 GeneBank (GQ290211), CTX-M-15, OXA-1, variant aac (6′)-Ib-cr, tet(A) genes, VIM and KPC were present and it was found to carry a class 1 integron. No mutation was found in gyrA but in ParC a mutation at 520 G to C, with amino acid change 174 Val (GTC) to Leu (CTC) was detected. QnrA, B, S and integron 2 were not present.