To compare and characterize the antimicrobial resistance and multidrug resistance patterns of Salmonella isolates obtained from Honduras based on the source of isolation.

A total of 134 Salmonella isolates from Honduras were subjected to phenotypical antimicrobial resistance analysis for 14 antibiotics from 9 different antibiotic classes. The isolates were collected from different sources, including beef cattle during harvesting (n = 78), poultry (n = 26) and retail beef (n = 30). Antimicrobial resistance (AMR) analysis was conducted following the National Antimicrobial Resistance Monitoring System (NARMS) protocol. Minimum inhibitory concentrations (MIC) were obtained using the Sensititre OptiRead system and Sensititre software SWIN (V3.3). Results were categorized as susceptible, intermediate or resistant according to the revised Clinical and Laboratory Standards Institute (CLSI) breakpoints.

A total of 22% (30/134) of the isolates were multidrug-resistant (MDR), which indicates resistance to at least 3 or more classes of antibiotics. Antibiotic resistance patterns of all Salmonella isolates were analyzed detecting difference among antibiotics (p < 0.05). The results indicate that Salmonella had higher resistance (p < 0.05) to cefoxitin antibiotic with 25% (34/134), followed by amoxicillin-clavulinic acid at 23% (31/134), ampicillin, gentamicin and streptomycin with 19% (25/134), and ciprofloxacin with 16% (21/134). Moreover, Salmonella showed 13% (18/134) resistance to trimethoprim-sulfamethoxazole, 12% (16/134) to nalidixic acid, 10% (14/134) to tetracycline, and 8% (11/134) to azithromycin. Futhermore, resistance of 4% (6/134) was found for ceftiofur, ceftriaxone, and chloramphenicol. In contrast, all Salmonella isolates exhibited susceptibility to the sulfisoxazole antibiotic. MDR patterns were found to be significantly different (p < 0.05) among isolate source. Salmonella isolates from retail beef trim had the highest multidrug resistance patterns (p < 0.05) with 57% (17/30), followed by beef cattle during harvesting 15% (12/78) and poultry sources with 4% (1/26).

High levels of MDR were found in retail meat products originated from Honduras, suggesting a risk and public health concern to consumers. Resistant pathogens and resistance genes could potentially be transmitted from the final products to humans and bacteria using several transmission routes. Cross contamination in wet markets could result in transfer and spreading of MDR Salmonella among consumers. The reduction of antibiotic use in the Honduran animal industry may reduce and limit Salmonella antibiotic resistance patterns in animal products.