Molecular Identification of TEM and SHV Genes in Extended Spectrum Beta-lactamase Producing Escherichia coli and Klebsiellae pneumoniae Isolates in a Tertiary Care Hospital, Bangladesh

Abstract

Extended spectrum b-lactamases (ESBLs) are enzymes encoded by mutation of a class of genes such as TEM, SHV, OXA and CTX etc. in gram negative Enterobacteriaceae. In this study, the first report was focusing on the multidrug resistance in Escherichia coli and Klebsiella pneumoniae producing extended spectrum b-lactamases (ESBLs) encoded from mutated TEM and SHV genes. Out of 108 bacterial isolates, 79% were found as ESBL positive and 21% were ESBL negative; 42% were E. coli, 37% were K. pneumoniae by chromogenic agar plate method. Further in disk diffusion method, 75% were ESBLs positive strains and 25% were ESBLs negative. The 50 strains (25 E. coli and 25 K. pneumoniae) were examined for Multiplex PCR to detect TEM and SHV genes. Out of 50 samples, 41 strains were PCR positive. In case of E. coli, 36% contained both TEM and SHV genes; 40% contained TEM gene; 8% contained SHV gene; 16% were PCR negative and contained others genes. In case of K. pneumoniae, 40% strains contained both TEM and SHV genes; 28% contained TEM gene; 12% contained SHV gene; 20% were PCR negative for and contained others genes. The length of TEM gene was around 1100-1200 bp and SHV around 450-500 bp determined comparing with 1 kb and 200 bp ladder respectively. ESBLs production is significant in phenotypic laboratory screening. Presence of both TEM and SHV genes in ESBLs producing bacteria was more common. Length of TEM gene was higher than SHV gene.

Keywords

• esbls
• cephalosporins
• monobactams
• dna
• pcr