Carbapenemase Producers Among Extensive Drug-Resistant Gram-Negative Pathogens Recovered from Febrile Neutrophilic Patients in Egypt

PURPOSE: This study aimed to detect the prevalence of carbapenemase producers (CPs) among extensive drug-resistant (XDR)-carbapenemase producing Gram-negative bacteria (GNB) recovered from various clinical specimens of hospitalized neutrophilic febrile patients in two major tertiary care hospitals in Egypt. METHODS: Standard methods were used to evaluate the antimicrobial susceptibility of clinical isolates according to the guidelines of the Clinical and Laboratory Standards Institute (CLSI). Phenotypic and genotypic analysis of CPs were carried out and statistically analyzed using standard methods. RESULTS: Three hundred and forty-two GNB were obtained from 342 clinical specimens during the period of the study, where 162 (47%) were enterobacterial isolates, including, 63 (18.4%) Escherichia coli, 87 (25.4%) Klebsiella spp., 5 (1.46%) Enterobacter cloacae, 5 (1.46%) Salmonella spp. and 2 (0.6%) Proteus and 180 (53%) were non-fermentative bacilli including, 129 (37.7%), Acinetobacter baumannii, and 51 (14.9%), Pseudomonas spp. Out of the 342 GNB, 188 (54.9%) isolates were multi-drug resistant (MDR). Of these, 52 (27.6%) were XDR as well as CPs as confirmed phenotypically. The MIC of imipenem against the XDR GNB against showed either low (11 isolates; 21.1%; MIC range =4–32 µg/mL) or high levels of resistance (41 isolates; 78.8%; MIC range = 64-≥1024). The most prevalent carbapenem resistance (CR) genes were blaKPC (63.5%) followed by blaOXA-48 (55.7%) and blaVIM (28.8%). No significant association could be observed between the MIC level and the presence of CR genes (P value >0.05). CONCLUSION: High prevalence of MDR (54.9%) and XDR (27.6%) GNB pathogens associated with high levels of resistance to carbapenems were observed. All XDR GNB were CPs and tested positive for at least one of the CR genes. However, most of them (78.8%) showed a high level of CR (MIC range = 64-≥1024) with no significant association with the CR genes.