Resistance Profile of Enterobacteria Isolated from Pathological Samples in Hospitals of N’Djamena and Abéché in Chad

Abstract

Background: The global rise of multidrug-resistant (MDR) bacterial strains poses a significant public health challenge across both developing and industrialized nations. This study aimed to generate nationally relevant data on antimicrobial resistance in Chad.

Methodology: A total of 532 clinical specimens—comprising 401 urine and 131 stool samples—were randomly collected from inpatients and outpatients of all age groups at two hospitals in N’Djamena and Abéché between May and December 2021. Urine samples were cultured on CLED agar and stool samples on MacConkey agar. Bacterial identification was performed using biochemical methods including Gram staining, oxidase testing, API 20E (bioMérieux), and Enterosystem 18R (Liofilchem). Antimicrobial susceptibility testing was conducted using the Kirby-Bauer disk diffusion method.

Results: The overall prevalence of Enterobacteriaceae was 19.55% (104/532), with Escherichia coli being the most frequently isolated species (79.80%), followed by Klebsiella spp. (6.73%) and Enterobacter spp. (4.80%). All Enterobacteriaceae isolates exhibited complete resistance (100%) to ampicillin and ticarcillin. Resistance to fluoroquinolones varied significantly by location: 6 of 35 strains in Abéché were resistant to ciprofloxacin and levofloxacin, compared to 61 of 69 and 57 of 69 strains in N’Djamena, respectively. Notably, E. coli isolates in N’Djamena also showed resistance to imipenem (6/59).

Conclusion: The high prevalence of antibiotic resistance may be attributed to self-medication, inappropriate prescriptions, and the spread of nosocomial strains. Urgent measures are needed to regulate antibiotic use both within healthcare facilities and the wider community.