Multi-drug resistance in clinical isolates of Gram-negative bacilli in a tertiary care hospital of Assam

The widespread use of β-lactam antibiotics has lead to the development of resistance to this group of antibiotics in bacterial pathogens due to various types of β lactamase production. Amongst the mechanisms of resistance to third generation cephalosporins, production of extended spectrum β-lactamases (ESBLs) and AmpC β lactamases is the most common1. Since both ESBL and AmpC β-lactamase are encoded on plasmids and confer a selective advantage to strains harbouring these in a hospital setting, it is important to know the occurrence of ESBL and AmpC producing strains as well as their antibiotic susceptibilities to newer agents to guide empirical therapy. This laboratory based study was carried out over a period of one year from May 2011 to April 2012 at the department of Microbiology, Assam Medical College and Hospital, Dibrugarh, Assam, India to determine the occurrence of multi-drug resistant Gram-negative bacilli producing AmpC β-lactamases and ESBL causing infection in hospitalized patients.