The Emergence of Carbapenem- and Colistin-Resistant Enterobacteria in Senegal

Abstract

Antibiotic resistance is a public health problem. The emergence of carbapenemase-producing Enterobacterales (CPE) infections is a concern, particularly in Senegal. (1) Methods: Between January 2019 and July 2022, 240 isolates of enterobacteria resistant to third-generation cephalosporins and imipenem from biological samples from Fann Hospital (Dakar) and Hôpital Paix (Ziguinchor) were selected. The isolates were identified by MALDI-TOF mass spectrometry, and susceptibility tests were performed by the disk diffusion method. Antibiotic-resistance genes for class A beta-lactamases, carbapenemases, and plasmid resistance to colistin resistance (mcr-1–8) were screened by RT-PCR. (2) Results: The 240 enterobacteria were composed of: Escherichia coli (60.83%), Klebsiella pneumoniae (21.67%), Enterobacter cloacae (13.75%), Citrobacter freundii (2.08%), Serratia marcescens (0.83%), Klebsiella aerogenes (0.42%), and Proteus mirabilis (0.42%). Class A beta-lactamase genes were found in 229 isolates (70.41% blaTEM, 37.5% blaSHV, 83.75% blaCTX-A, and 0.42% blaCTX-B). The carbapenemase genes blaOXA-48 and blaNDM were found in 25 isolates, including 14 isolates with blaOXA-48, 13 isolates with blaNDM, and 2 isolates with both genes simultaneously. The mcr-8 gene was found in one isolate of E. cloacae. (3) Conclusions: The epidemiology of antibiotic-resistance genes in enterobacteria in Senegal shows the emergence of CPEs. This phenomenon is worrying, and rigorous surveillance is necessary to avoid further spread.

Keywords

• enterobacteria
• carbapenemase
• colistin