Phenotypic and genotypic characterization of extended-spectrum beta-lactamase-producing Enterobacteriaceae in a Moroccan hospital

Abstract

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) is a major public health problem in hospitals and in the community. The objective of this work was to describe the epidemiology of ESBL-E, to study their resistance profile and to determine the genes encoding the ESBL phenotype. This is a retrospective study conducted in the bacteriology laboratory of the Mohamed V Military Training Hospital in Rabat, and covering all isolates of Enterobacteriaceae from 01/01/2018 to 31/12/2020. The molecular study of ESBL genes involved a representative sample of all ESBL isolates. The overall prevalence of ESBLs in isolated Enterobacteriaceae (1402/10268) is 13.65%. The urinary tract was the main site of isolation of ESBL (61%). The bacterial species most concerned are Escherichia coli (41,9%), Klebsiella pneumoniae (42,2%) and Enterobacter cloacae (11,9%). The study of antibiotic susceptibility showed a resistant profile marked mainly by 100% resistance to 1st generation cephalosporins (1GC) and 3rd generation cephalosporins (3GC), 55% to piperacillin-tazobactam, 16% to imipenem, 87% to fluoroquinolones. Molecular typing of ESBL strains showed a prevalence of CTX-M (95%), SHV (50%) and TEM (56%). The CTX-M-1 and the CTX-M-9 groups were the most common (96,19% and 7,62 % respectively), and CTX-M15 was found in 78,10% of CTX-M-1 ESBL positive isolates. Most strains had more than two coexisting resistance genes. The prevalence rate of ESBL-E is critical, and preventive action at different levels (prescriber, biologist, hospital, patient, etc.) are necessary in order to limit their spread and to manage a better therapeutic strategy.