Antimicrobial resistance and toxin profiles of enterotoxigenic Escherichia coli in children under five years old with diarrhoea in Ouagadougou, Burkina Faso: a sentinel surveillance study.

内容摘要

Enterotoxigenic Escherichia coli (ETEC) remains a major cause of paediatric diarrhoeal disease in sub-Saharan Africa. Increasing antimicrobial resistance (AMR) threatens the effectiveness of empirical treatment, yet data on ETEC-specific resistance patterns and toxin profiles in Burkina Faso are scarce. This study assessed the prevalence, toxin gene distribution, and antimicrobial susceptibility of ETEC among children with acute diarrhoea in Ouagadougou, Burkina Faso. A hospital-based cross-sectional sentinel surveillance study was conducted at the "Centre Hospitalier Universitaire Pédiatrique Charles De Gaulle (CHUP-CDG)", Ouagadougou, from May 2023 to April 2024. Stool samples were collected from 383 children under five years of age presenting with acute diarrhoea. ETEC was identified by culture followed by multiplex PCR targeting eltB (LT), estA1 (STp), and estA2 (STh) genes. Antimicrobial susceptibility testing was performed using the Kirby-Bauer disk diffusion method and interpreted according to EUCAST 2023 criteria. Multidrug resistance (MDR) was defined as non-susceptibility to at least one agent in three or more antimicrobial classes. ETEC was detected in 16 of 383 children, yielding a prevalence of 4.2% (95% CI: 2.4-6.7). The highest proportion of cases occurred in children aged 12-23 months (43.8% (7/16)). LT-producing strains predominated (50.0% (8/16)), followed by STp-producing strains (43.8%), with one LT + STh isolate (6.3% (1/16)). Antimicrobial resistance was high to commonly used oral agents, including trimethoprim (93.3% (14/15)), sulfamethoxazole (73.3% (11/15)), and ampicillin (66.7% (10/15)). Resistance to third-generation cephalosporins was substantial (ceftazidime 57.1% (8/14), cefotaxime 53.3% (8/15)), and fluoroquinolone resistance reached 40.0% (6/15) for ciprofloxacin. Eleven of 15 tested isolates (73.3% (7/15)) were classified as multidrug-resistant. All isolates remained susceptible to carbapenems and cefoxitin. While 80.0% (12/15) of isolates exhibited a phenotypic profile suggestive of extended-spectrum beta-lactamase (ESBL) production, only one isolate 6.7% (1/15) was phenotypically confirmed as an extended-spectrum beta-lactamase (ESBL) producer by double-disk synergy testing. The high prevalence of in vitro antimicrobial resistance among ETEC isolates suggests that the effectiveness of commonly used oral antibiotics as empirical treatment options in this setting may be compromised. The 73% MDR prevalence and ESBL production necessitate urgent antimicrobial stewardship implementation, enhanced surveillance systems, and accelerated ETEC vaccine development for this vulnerable population.