Resistance Patterns of Multi-Drug Gram-Negative Isolates to Carbapenems: An Emerging Problem

Abstract

Objective: Infections caused by multidrug-resistant (MDR) Gram-negative bacteria and resistance to carbapenems constitute a major public health problem worldwide, due to limited treatment options and high mortality rates. In this study, we aimed to determine the resistance profiles of MDR Gram-negative bacilli isolated from clinical samples to carbapenems. Material and Method: Specimens, from which MDR Gram-negative bacteria were isolated, were cultured onto 5% sheep blood and EMB agar, and VITEK 2 automated system (bio M & eacute;rieux, France) was used for identification and antimicrobial susceptibility testing. Data were analyzed using chi-square and Fisher's exact tests. Results: 1072 MDR bacterial strains were isolated from the specimens of 272 patients, with the majority of transtracheal aspirates (64%) sent predominantly from palliative care (49.8%) and intensive care (42%) units. The leading pathogens were Pseudomonas aeruginosa (42,1%), Acinetobacter baumannii (31,2%), and Klebsiella spp (22,5%). The highest resistance rate among carbapenems was detected to meropenem (91,6%), followed by imipenem (44,3%) and ertapenem (25%). While ertapenem resistance was significantly lower in P. aeruginosa strains (p<0,01), meropenem resistance was significantly higher in A. baumannii strains when compared to other antibiotics. Conclusion: Since Gram-negative MDR bacteria continue to spread rapidly, monitoring resistance profiles through active hospital surveillance is crucial to determine the appropriate treatment. The data obtained in this study once again highlight the importance of resistance to carbapenems and is considered to contribute to epidemiological data.