Prevalence of ESBL, AmpC β-lactamases and MRSA among uropathogens and its antibiogram

Abstract

Urinary tract infections (UTIs) are one of the most common bacterial infections in humans. Current knowledge on antimicrobial susceptibility pattern is essential for appropriate therapy. Therefore the aim of the present study was to determine the distribution and antibiotic susceptibility pattern of bacterial strains, with special reference to ESBL, AmpC β-lactamase and MRSA production. A total of 325 clinical isolates were collected from UTI patients from various tertiary care hospitals over a period of 6 months (June 2011 to December 2011). The antimicrobial susceptibility to various drugs was studied by the disc diffusion method as guided by CLSI guidelines. Confirmation of the extended spectrum β-lactamase (ESBL), AmpC β-lactamase and methicillin resistant Staphylococcus aureus (MRSA) production was done by an E-test respectively. Of the 325 isolates, 225 were characterized as gram negative and 77 isolates as S. aureus isolates. The majority (69.3 %) of the isolates were from females compared to males (30.7 %). Prevalence of ESBL and AmpC β-lactamase and the coexistence of the phenotype (ESBL+ AmpC β-lactamase) and MRSA in the urinary isolates were found to be 48.9 %, 20.4 %, 6.2 % and 27.5 % respectively. Ampicillin/sulbactam, norfloxacin should be no longer considered as first line of drugs for UTI, because of high resistance. Parentral drugs such as aminoglycosides, carbapenems and piperacillin/tazobactum can be the alternative choice for complicated UTI. Also, control measures such as judicious use of antibiotics, formulation of infection committee may control the spread of resistance.