Abstract
Increasing resistance to extended-spectrum cephalosporines (ESC) among Egyptian isolates of Klebsiella pneumoniae has already been previously reported. This work devotes to investigate the genetic basis of resistance to ESC in K. pneumoniae in Cairo, Egypt. Disc diffusion test, minimum inhibitory concentrations, and phenotypic screening for extended spectrum beta-lactamses (ESBLs) and plasmid-mediated AmpC beta-lactamases (PABLs) were carried out was done for 21 K. pneumoniae isolates collected during 2010 at the Sayed Galal Hospital in Cairo, Egypt. Genes for ESBLs and PABLs were sought by PCR and DNA sequencing. Matting out assay was performed to determine the mobility of bla genes. Six (28.57%) of 21 clinical isolates K. pneumoniae were non-sensitive to ESC. Five isolates were ESBL producers and one isolate was positive for PABLs. CMY-2 and SHV-1 were detected in the isolate which produce PABLs. All five ESBL-producing isolates harbour SHV and CTX-M. CTX-M-15 was detected in 100% of the isolates and SHV-12 was detected in two isolates. CTX-M-15 coproduced with SHV-12 in two isolates. TEM-1 was detected in two isolates and co-existed with CTX-M-15. bla(CTX-M-15) and bla(CMY-2) genes were transferable and associated with class 1 integron. Resistance to ESC was due to CTX-M-15, SHV-12 and CMY-2 in K. pneumoniae. This is the first description of SHV-12 and CMY-2 in K. pneumoniae isolates from Egypt.