Antibiotic resistance in Gram-negative bacilli isolated from livestock farms in Gabon

The aim of this study was to determine the prevalence of antibiotic resistance among Gram-negative bacilli on livestock farms. A total of 356 faecal samples from farms in 9 cities across 6 provinces were collected. Isolates obtained after culture and isolation were identified using the API 20E gallery. Following culture, 51.4% of the samples yielded colonies. Identifications revealed Escherichia (30.0%), followed by Pseudomonas (26.2%), Serratia (17.5%), and Enterobacter (6.56%), among others. Antibiotic susceptibility testing was conducted using the disc diffusion method. Susceptibility tests indicated resistance to Ampicillin (68.3%), Amoxicillin + Clavulanic Acid (66.7%), Cefotaxime (65.6%), Cefepime (60.1%), Aztreonam (59%), and Ertapenem (49.2%). Maximum resistance to Ceftazidime (77.0%) was observed, particularly in Escherichia, Pseudomonas, Serratia, and Enterobacter, posing a public health problem and a threat to the health of these Populations. All identified isolates exhibited antibiotic resistance at least to three or more antimicrobial family of antibiotics, and were multidrug resistance (MDR) bacteria. Some of them are associated with ESβL (7.1%). Given that MDR bacteria were isolate from farm animals that are intended for human consumption, there is a significant risk of transmitting MDR strains to consumers, posing a substantial threat to human health.