Antimicrobial resistance pattern of clinical isolates of <i>Pseudomonas aeruginosa</i> and <i>Escherichia coli</i> on carbapenems

Abstract

Background: Carbapenems are the most effective and important  therapeutic options to serious infections caused by Enterobacteriaceae and Pseudomonas aeruginosa isolates. However, Carbepenems resistant  isolates of  Enterobacteriaceae and Pseudomonas aeroginosa are increasing worldwide. This study, therefore, was carried out to determine the resistance pattern of clinical isolates of Pseudomonas aeruginosa and Escherichia coli to Carbapenems.

Methods: Fifty (50) E. coli and forty seven (47) Pseudomonas aeruginosa  isolates were studied. Antibiotic  Susceptibility test was performed as recommended by the CLSI. The antibiotics used were Ertapenem,  Imipenem, Colistin Sulphate, Levofloxacin, and Piperacillin/Tazobactam.

Results: Out of 97 clinical isolates subjected to drug susceptibilities test,  Pseudomonas aeruginosa showed resistance to Ertapenem (87.2%); followed by Levofloxacin (19.1%), Colistin sulphate (12.8%),  Piperacillin/tazobactan (4.3%) and Imipenem (2.1%) while E.coli displayed resistance to Ertapenem (30%), Levofloxacin (20%) and Colistin sulphate
(4%). Interestingly, E coli was susceptible to Imipenem (0%) and   Piperacillin/tazobactan (0%). A significant effect of Ertapenem on  Pseudomonas aeruginosa was recorded. Also a significant effect of  Piperacillin/Tazobactam was recorded on E coli. No significant effect was recorded among the other antibiotics on P aeruginosa or E coli.

Conclusion: There is a high level of Carbapenems resistance among the clinical isolates of Pseudomonas aeruginosa compared to Escherichia coli in this study. Considering the therapeutic value of Carbapenems as one of the last options for the treatment of Enterobacteriaceae and Pseudomonas aeruginosa infections, rational Carbapenems usage is essential to reduce selective pressure over Enterobacteriaceae and Pseudomonas aeruginosa clinical isolates.

Keywords: Carbapenems, Antibiotics, Nosocomial, Susceptibility