Prevalence of Extended Spectrum Β-Lactamase (ESBL) Organisms Associated with Clinical Infections and their Characterization through Plasmid Profiling

Extended spectrum -lactamases are plasmid mediated. These plasmids produce enzymes that hydrolyze broad spectrum cephalosporins and monobactams. They acquire resistance prevalently through plasmid encoded. Study determines plasmids and their correlation with drug resistance against many antibiotics that limits their therapeutic implications. Bacteriological analysis of 50 samples susceptible for ESBL was conducted. The samples subjected to susceptibility tests and detection of ESBL. Plasmid DNA isolation of all the ESBL positive strains of E. coli was done by alkali-lysis method. Finally the presence of plasmid was correlated with susceptibility to beta lactam drugs. ESBL was detected in 56% (28 out of 50 isolates). Maximum ESBL incidence recorded of E. coli (30 %) followed by Klebseilla pnemoniae (18%) and Pseudomonas aeruginosa (8 %). ESBL exhibited high-level resistance to beta lactam antimicrobial agents like  Amoxiclave (56%), Cefuroxime (54%), Cephotaxime (54%), Ceftriaxon (50%), Ceftazidime (46%) and Cefixime (36%). During plasmid profiling of eight isolates of ESBL E. coli showed one to four definite bands indicating the presence of different plasmids. ESBL’s constitute a growing class of plasmid-mediated -lactamases which confer resistance to broad spectrum β-lactam antibiotics. Incidence of ESBL is continuously increasing globally with limited treatment alternatives and formulates treatment policy. Moreover, restricted use of the third generation cephalosporins lead to withdrawal of selective pressure and use of lactam and -lactamase inhibitor combinations may exert reverse mutation on these enzymes. There is a strong correlation between the number of plasmids harbored by an isolate and drug resistance.