Suryawanshi1, A.P Pichare2, M.S. Davane3,
1, 3, 4
of Microbiology, MIMSR Medical College, Latur(MS),INDIA.
& HOD Department of Microbiology, MIMSR Medical College, Latur (MS),INDIA.
Received 27 October
2011; Accepted 01 November 2011
Academic Editor: Dr.
beta lactamases (ESBLs) are rapidly evolving plasmid mediated;
TEM and SHV derived enzymes, capable of hydrolyzing
oxyimino-cephalosporins and monobactams. Bacteria producing ESBLs remain
an important cause for failure of therapy with cephalosporins and other
antibiotics. ESBL testing is useful for epidemiological or
infection control purposes.Aims: The present study was conducted
to detect ESBLs in strains of Escherichia coli isolated from
various clinical samples in a tertiary care hospital. Material and
Methods: A total of 272 non enteric randomly chosen non repetitive
E.coli isolates obtained over the period of one year from both
outpatient and hospitalized patients were studied. Out of 272 isolates,
191 (70.22%) were screened as ESBL producing. They were further studied
for ESBL production by phenotypic confirmatory disc diffusion test (PCDDT).
Results: It was observed that not all screen positive isolates
were confirmed as ESBL producers. Of the total 191 ESBL positive
isolates, the PCDDT method detected 168 (87.95%) cases. Overall
prevalence of ESBL in E.coli was found to be 61.76%. Only 4
strains (1.47%) were found resistant to imipenem and 11 strains (4.04%)
were found resistant to meropenem. Conclusions: The
present study shows that any of the three screening agents can be used
to detect potential ESBL producers. The routine antibiotic sensitivity
test may fail to detect ESBL mediated resistance. Therefore, screening
for detection of ESBL and confirmation of the same should be carried out
by PCDDT method as it is simple, reproducible, cost effective and
sensitive method. ESBL detection studies help to formulate an empirical
antibiotic policy to treat Gram negative infections in respective