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


OBJECTIVE
To determine the prevalence of ESBL (blaTEM, blaCTX-M, and blaSHV) genes among the members ofEnterobacteriaceae.


METHODS
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%).


CONCLUSIONS
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.
Department of Microbiology, Sri Aurobindo Institute of Medical Sciences Medical College and PG Institute, Indore, Madhya Pradesh, India; Department of Biochemistry, IGNOU, SOS, New Delhi, India.
Trupti
T
Bajpai
Department of Biochemistry, IGNOU, SOS, New Delhi, India.
M
M
Pandey
Department of Biochemistry, Sri Aurobindo Institute of Medical Sciences Medical College and PG Institute, Indore, Madhya Pradesh, India.
M
M
Varma
Department of Microbiology, Sri Aurobindo Institute of Medical Sciences Medical College and PG Institute, Indore, Madhya Pradesh, India.
G S
GS
Bhatambare
Beta-lactam antibiotics; extended-spectrum beta-lactamases; polymerase chain reaction