Antibacterial resistance is a growing concern worldwide, including in Mozambique. Diarrhea is an important cause of mortality in Mozambique, yet few local studies have reported on the resistance of bacterial pathogens in this context. Therefore, this study aims to characterize antibiotic susceptibility patterns of Salmonella, Shigella and Campylobacter spp. among patients with diarrhea, including those who are HIV-infected and-uninfected. We conducted antibiotic susceptibility testing on 157 stool isolates recovered from 129 patients aged between 0 and 80 years with diarrhea, including HIV infected (n = 68) and-uninfected individuals (n = 61), assisted at two health centers in Maputo city. The study was conducted between November 2021 and May 2022. The isolates comprised of 99 Salmonella, 45 Shigella and 13 Campylobacter strains. We tested six antibiotics listed on the national essential medicines list, including ciprofloxacin, erythromycin, azithromycin, trimethoprim-sulfamethoxazole, gentamicin, and tetracycline. All isolates were resistant to at least one antibiotic. A high percentage of Salmonella spp. isolates were found to be resistant to trimethoprim-sulfamethoxazole (89.9%, n=89), erythromycin (88.9%, n=88) and tetracycline (76.8%, n=76). In addition, 86.6% (n=39) and 68.9% (n=31) of Shigella isolates were resistant to trimethoprim-sulfamethoxazole and tetracycline, respectively. The majority of Campylobacter isolates (92.3%, n=12) were resistant to erythromycin, azithromycin and tetracycline. Multidrug resistance (MDR) was observed in 79.8% of Salmonella spp., 76.9% of Campylobacter spp., and 57.8% of Shigella spp. Isolates of Shigella spp. obtained from patients without HIV infection presented a significantly higher resistance to erythromycin and azithromycin, or they exhibited multidrug resistance more frequently than isolates obtained from patients with HIV infection (p < 0.05). All Shigella spp. and Campylobacter spp. isolates were susceptible to gentamicin. Our study highlights concerning rates of antibiotic resistance and MDR among diarrheal bacterial pathogens in Mozambique. Urgent interventions are essential to prevent the spread of resistant strains.

Key-words: antibiotic resistance, Salmonella, Shigella, Campylobacter, Maputo.