Mediterranean Journal of Infection, Microbes and Antimicrobials (Jun 2022)
Antimicrobial Activities of Piperacillin-tazobactam Plus Oxyimino-cephalosporins and Gentamicin against Extensively Drug-resistant Non-carbapenemase-producing Enterobacteriaceae Isolated from Immunocompromised Patients in a Nigerian Hospital
Abstract
Introduction: Antimicrobial resistance among the Enterobacteriaceae members has progressed from multi to extensively drug-resistant status, thereby limiting the treatment options for immunocompromised patients (ICPs). Monotherapy application has been proven unsuccessful in many cases, thereby necessitating a combination therapy for optimal treatment. Materials and Methods: The incidence of extensively drug-resistant (XDR) pathogens among ICPs was studied and they were screened for β-lactamase production, and the effectiveness of antibiotic combination against the XDR Enterobacteriaceae isolated from a Federal Medical Center in Nigeria was determined using the standard Clinical and Laboratory Standards Institute methods. Checkerboard assay was used to determine the synergy between piperacillin-tazobactam (TZP)/amoxicillin-clavulanic acid (AMC) and each of ceftazidime (CAZ), ceftriaxone (CRO), and gentamicin (GN) by using fractional inhibitory concentration indices. Results: A total of 68 Enterobacteriaceae members were isolates and 15 (22.1%) were XDR. Of the 68 isolates, 53.3%, 13.3%, and 0% were extended-spectrum β-lactamases (ESBL), AmpC, and carbapenemase producers, respectively. A resistance to meropenem was expressed by 37.5% in XDR E. coli, 60% in K. pneumoniae, and 100% in Enterobacter aerogene. Equally alarming was the colistin resistance expressed by 50% in XDR E. coli and 20% in K. pneumoniae. Mono antibiotics with favorable activities against the XDR Enterobacteriaceae included colistin, tigecycline, and meropenem. The synergy was observed for XDR E. coli and K. pneumoniae when TZP was combined with CAZ and CRO. No synergy was observed when AMC was combined with either CAZ or GN. Conclusion: This study demonstrated the incidence of XDR Enterobacteriaceae among ICPs and suggested TZP plus CAZ or CRO as a useful treatment combination for infections due to XDR Enterobacteriaceae, including the co-producers of ESBL and AmpC β-lactamase.
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