Pattern survey of Antibiotic resistance of clinical isolates of ESBL strains and determination of enzymatic relationship with clinical specimen type

Background: Differences in clinical isolates may affect the frequency of Extended Spectrum Beta-Lactamase enzymes (ESBLs) in some gram-negative bacteria. The aim of this study was to pattern survey of Antibiotic resistance of clinical isolates of ESBL strains and determination of enzymatic relationship with clinical specimen type.

Methods: In this descriptive-analytic study, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae and Enterobacter cloacae were identified by biochemical tests. Combination disk test was used to determine ESBL strains. Chi-square test with significant range of P<0.05 was used to examine the relationship between variables.

Results: Out of 270 isolated gram-negative isolates, 95 isolates was produced ESBL enzyme. Of the 95 isolates, 28 isolates (29.47%) were E. coli, 22 isolates (23.15%), P. aeruginosa, 19 isolates (20%), A. baumannii, 17 isolates (17.89%) of K. pneumoniae and 9 isolates (33.3%) were E. cloacae. There was a significant relationship between the presence of ESBL enzymes and the type of clinical specimen, so that isolates with this enzyme had the highest frequency in the wound and urine specimens.

Conclusion: Considering the relationship between type of clinical specimen and the frequency of ESBL enzyme in resistant strains, some environmental factors and underlying variables such as the type of clinical specimen can increase the abundance of ESBL enzymes.