Comparative study on occurrence of class A and class C beta;-lactamase genes and their co-occurrence in Indian Enterobacteriaceae during years 2009 and 2010

ObjectiveTo determine the occurrence of class A and class C β-lactamase genes and their co-occurrence in Indian Enterobacteriaceae.Methods52 third generation cephalosporin resistant isolates were phenotypically detected by combination disk method and screened by PCR to identify class A and class C type β-lactamase genes.ResultsOf the 52 isolates, 94.2% (49) were found harboring any of the blaESBLs. blaCTX-M, blaSHV and blaTEM were present in 82.6% (43/52), 59.6% (31/52), and 42.3% (22/52) isolates, respectively. Of the 49 ESBL positive isolates 57.1% (28/49) showed co-occurrence of blaampC with blaESBLs. On the contrary, the collection from 2009 showed their co-occurrence in 81.4% isolates.ConclusionsThe comparative study shows a downward trend for co-existence of blaESBLs with blaampC from 2009 to 2010. Further large scale studies are needed to address the co-occurrence of class A and class C β-lactamases in India and the resistance trend occurring over a period of time.