Detection of extended spectrum beta-lactamase from clinical isolates in Davangere.
Extended spectrum beta-lactamase enzymes (ESBLs) are enzymes that have the ability to hydrolyze oxyiminocephalosporins and infections by isolates producing them are often difficult to treat. A study to detect the presence of these enzymes in isolates was conducted by our hospital. A total of 207 non repetitive isolates were screened for resistance to any of five screening agents. Those with suspicious profiles were checked for ESBL production by double-disk approximation or a synergy test. The isolates were also subjected to a phenotypic confirmation test as recommended by CLSI (formerly NCCLS). Various cephalosporins-beta-lactamase inhibitor combinations were also tested. Of the 204 (98.5%) screen-positive isolates, only 126 (61.7%) were identified as ESBL producers. Of these, 26.1% of the isolates were positive by using the double-disk synergy test (DDST) method alone, 13.4% were positive using the method recommended by CLSI, and 60.3% of the isolates were positive by both the DDST and CLSI methods. We also report a high percentage of resistance to cefoxitin (96.8%) indicating changes in porins.
Sridhar Rao
P N
PN
Department of Microbiology, JJM Medical College, Davangere 577 004, Karnataka, India. mail@microrao.com
Basavarajappa
K G
KG
Krishna
G Leela
GL
D000046:Academic Medical Centers; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018550:Cephalosporin Resistance; D002511:Cephalosporins / Q000494:pharmacology; D004755:Enterobacteriaceae / Q000145:classification / Q000187:drug effects / Q000201:enzymology* / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000382:microbiology; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests / Q000379:methods*; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000096:biosynthesis*; D047090:beta-Lactams / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D047090:beta-Lactams; D001618:beta-Lactamases