Prevalence of Extended Spectrum β-lactamase SHV and OXA Producing Gram Negative Bacteria at Tertiary Care Hospital of Lahore, Pakistan

Abstract

The present study was planned to detect drug resistant genes like “blaSHV” and “blaOXA” among gram negative rods (GNRs) isolated from different clinical specimens, collected from Jinnah Hospital Lahore during January-December 2015. Majority of the GNRs were isolated from urine samples (55%) followed by pus (28%), blood (7%), sputum (6%), Broncho-alveolar lavage (2%), fluid (1%) and from tips (1%). The isolated organisms were Escherichia coli (n=60), Klebsiella pneumoniae (n= 20), Enterobacter cloaca (n= 09), Enterobacter aerogenes (n= 02), Proteus mirabilis (n= 05), Proteus vulgaris (n=02) and Citrobacter freundii (n= 02). Extended spectrum beta lactamases (ESBL) production was screened by double disc synergy test (DDST) and combination disc method as per Clinical Laboratory Standard Institute (CLSI) guidelines 2015. Presence of “blaSHV” and “blaOXA” genes was tested by PCR technique. Every isolate was ESBL positive and resistant against third generation cephalosporin and Aztreonam. Notably, 15% of ESBL producing strains harbored blaSHV gene while 43% were positive for blaOXA gene. In a nutshell, diverse variety of ESBL-positive GNRs is distributed, the findings of the present study should be considered for planning strategies to treat and prevent the further spread of ESBL-producing gram-negative rods infections.