ANTIBIOTIC SUSCEPTIBILITY PATTERN AMONG CLINICAL STRAINS OF KLEBSIELLA PNEUMONIA ISOLATED FROM URMIA UNIVERSITY TEACHING HOSPITALS, AND DETERMINATION OF MIC AGAINST IMIPENEM IN RESISTANT ISOLATES

In recent years, the emergence of multi drug resistant Klebsiella pneumonia is
responsible for many therapeutic problems all over the world. Nowadays carbapenems are often
considered as the final options for antibiotic treatment of infections caused by most Gram-negative
bacilli. The aim of this study was to determine antibiotic resistance pattern (with focus on
carbapenems) of K. pneumoniaeisolates from clinical specimens of in-patients and out-patients
admitted to Urmia University of Medical Sciences teaching hospitals.
Materials & Methods: In this descriptive-analytical study, 182 isolates of K. pneumonia were
investigated. All bacterial isolates were identified as K. pneumoniae by using standard microbiological
tests. Antimicrobial susceptibility testing of confirmed isolates was carried out by disk diffusion
method proposed by (Kirby-Bauer) against 12 different antibiotics. The minimum inhibitory
concentration (MIC) of imipenem for each isolate was determined using E-test method.
Results: Accordingly, 43 isolates (23.6%) were resistant to imipenem, and 45 isolates (24.7%)
belonged to multiple drug resistant (MDR) phenotypes. These isolates demonstrated high resistance to
imipenem and meropenem. The MIC of imipenem for resistant isolates was ≥32 µg/ml.
Conclusion: Considering the high prevalence of resistance to imipenem, especially in Klebsiella
pneumonia isolates from patients admitted to ICU wards in the present study and various reports from
other countries, precaution should be taken in the administration of these drugs. Also determination of
bacterial susceptibility prior to prescription of antimicrobial agents is crucial for proper treatment and
preventing the dissemination of antimicrobial resistance.