Prevalence of TEM, SHV, and CTX-M Beta-Lactamase genes in the urinary isolates of a tertiary care hospital

Abstract

Introduction:Extended-spectrum beta-lactamases (ESBLs) are the major cause of resistance to beta-lactam antibiotics such as penicillins, cephalosporins, and monobactams. They are derived from the narrow-spectrum beta-lactamases (TEM-1, TEM-2, or SHV-1) by mutations that alter the amino acid configuration around the enzyme active site.Aim:To determine the prevalence of ESBL (blaTEM, blaCTX-M, and blaSHV) genes among the members of Enterobacteriaceae.Methodology:The present prospective study was carried out from January 2015 to June 2015 in the Department of Microbiology and Molecular Medicine of a Teaching Tertiary Care Hospital. A total of 526 urine samples were studied. Seventy-eight isolates were subjected to polymerase chain reaction for detection of ESBL genes.Results:In our study, ESBL genes were detected among 18 (45%) phenotypically confirmed ESBL producers and 20 (52.5%) phenotypically confirmed non-ESBL producers. The gene that predominated was blaTEM (48.7%), followed by blaCTX-M (7.6%) and blaSHV (5.1%).Conclusion:Definitive identification of ESBL genes is only possible by molecular detection methods. Phenotypic tests need to be evaluated periodically as their performance may change with the introduction of new enzymes.

Prevalence of CTXM, SHV, TEM AND OXA Genes among Extended-Spectrum Beta-Lactamase Producing <i>Klebsiella pneumoniae</i> from Mukuru Slum, Kenya

“…A report from Canada showed SHV 22 (43.14%) as the main group of ESBLs, followed by bla TEM 18 (35.29%) and blaCTXM 16 (31.37%) [14]. The differences between our study results and those of other authors indicated that the prevalence and type of ESBL genes may vary from one geographical region to another Bajpai et al, 2017 [4].…”

“…Beta-lactamases are grouped into four classes on the basis of their primary structure A, B, C, and D enzymes. Enzymes of classes A, C, and D have serine at the active site, whereas the class B enzymes are zinc-metalloenzymes [4].…”

Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae in Effluents of Different Hospitals Sewage in Biratnagar, Nepal

“…Extended-spectrum lactamases (ESBL) are enzymes that destroy the active sites of extended-spectrum third generation cephalosporins and monobactams thereby making bacteria resistant to such important antibiotics (Mahato et al, 2018). ESBLs are derived from genes TEM, SHV, and CTX-M by mutations that alter the amino acid configuration around the enzyme active site (Bajpai et al, 2017). ESBLs producing Enterobacteriaceae are prevalent worldwide especially in clinical environment.…”

Untitled

“…It may be clarified as ESBLs are primarily transmitted by plasmid, whereas AmpCs are primarily regulated by chromosome as seen in Table 3. Meanwhile, the presence of TEM, SHV, and CTX-M β-lactamase genes with β-lactamase development or ESBL phenotype 18 did not show any relationship in a study 18 . Likely, phenotypes that occur in genomic DNA without the existence of these genes indicate that the existence of other ESBL genes may be accountable for phenotypes of resistance, or opposite to those genes that are associated with other antimicrobial resistance.…”