Inducible AmpC Beta-Lactamase Producing Pseudomonas Aeruginosa Isolated In A Rural Hospital
Of Central India
Dr. S. Basak
Professor of Microbiology
J. N. Medical College
Sawangi (M), Wardha-442004 (M.S.)
Pseudomonas aeruginosa, one of the most common pathogen causing nosocomial infections, shows increasing resistance to β-lactam antibiotics especially by producing AmpC β-lactamase. Hence, this study was undertaken to determine the prevalence of inducible AmpC β-lactamases producing Pseudomonas aeruginosa in our hospital and their antibiotic susceptibility pattern to newer antipseudomonal antibiotics.
Consecutive 244 Pseudomonas aeruginosa isolates were studied. Isolates showing blunting of ceftazidime zone of inhibition adjacent to cefoxitin disc were considered as screen positive and were selected for confirmation of inducible AmpC β-lactamases producing by modified three dimensional test and AmpC disc test. In vitro susceptibility pattern of antipseudomonal antibiotics were done by Kirby Bauer disc diffusion method.
Out of 244 Pseudomonas aeruginosa isolates 47 (19.3%) were screen positive, which were confirmed by modified three dimensional test and AmpC disc test. The highest sensitivity pattern observed was Imipenem, Amikacin and Ciprofloxacin.
We conclude that to avoid misuse of antibiotics and to start proper antibiotics to hospitalized patients, tests for AmpC β-lactamases should be done in Clinical Microbiology laboratories.