Fosfomycin susceptibility of uropathogens at Charlotte Maxeke Johannesburg Academic Hospital

Lesego M Mothibi; Norma N Bosman; Trusha Nana

doi:10.4102/sajid.v35i1.173

Fosfomycin susceptibility of uropathogens at Charlotte Maxeke Johannesburg Academic Hospital

S Afr J Infect Dis. 2020 Oct 26;35(1):173. doi: 10.4102/sajid.v35i1.173. eCollection 2020.

Authors

Lesego M Mothibi^{1

2}, Norma N Bosman^{1

3}, Trusha Nana^{1

3}

Affiliations

¹ Department of Clinical Microbiology and Infectious Diseases, Faculty of Health Sciences, University of Witwatersrand, Parktown, South Africa.
² National Health Laboratory Services, Chris Hani Baragwanath Academic Hospital, Johannesburg, South Africa.
³ National Health Laboratory Services, Charlotte Maxeke Johannesburg Academic Hospital, Johannesburg, South Africa.

Abstract

Background: Multidrug-resistant uropathogens are becoming widespread both in community and hospital setting. Safe yet effective treatments are a priority. Fosfomycin is an antibacterial that displays good activity against most bacteria causing urinary tract infections (UTIs), including multidrug-resistant bacteria. The aim of this study was to evaluate fosfomycin susceptibility for uropathogens isolated from a microbiology laboratory at a tertiary academic hospital. In addition, this was compared to the susceptibility of other oral antimicrobials.

Methods: We conducted a retrospective analysis of laboratory reports for uropathogens isolated at Charlotte Maxeke Johannesburg Academic Hospital from September 2015 to August 2017. Antimicrobial susceptibility testing of the isolates was performed using the Kirby-Bauer disk diffusion method or the Vitek^® 2 system according to the Clinical and Laboratory Standards Institute.

Results: Overall susceptibility of fosfomycin for the 4700 Enterobacteriaceae isolates was 95.7%; 95% confidence interval (CI) 95.1-96.2. The overall susceptibility for fosfomycin against the gram-positives was 98.6%. There were 37.9% multidrug-resistant Enterobacteriaceae (MDRE) isolated during the study period. Fosfomycin displayed activity against 94.4% of extended-spectrum β-lactamase (ESBL) producers and 90.7% for carbapenem-resistant Enterobacteriaceae (CRE). None of the methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus isolates tested was fosfomycin resistant. The overall in vitro susceptibility was significantly higher for fosfomycin (p = 0.0001) compared to amoxicillin/clavulanic acid, cephalexin, cefuroxime, ciprofloxacin, trimethoprim/sulfamethoxazole and nitrofurantoin.

Conclusion: This study confirmed the high susceptibility of fosfomycin against UTI pathogens isolated at our institution. In an era of increasing antimicrobial resistance, fosfomycin represents a potential option for the treatment of UTIs at Charlotte Maxeke Johannesburg Academic Hospital.

Keywords: ambulatory; ciprofloxacin resistance; fosfomycin susceptibility; hospital; multidrug-resistant organisms; urinary tract infections; uropathogens.