Antibiotic Resistance Patterns in Shiga Toxin-Producing Escherichia coli (STEC), Salmonella, Shigella and Staphylococcus aureus Isolated at Two Communal Kitchens Located in Hanoi City, Vietnam

Abstract

The aim of our study was to investigate the antibiotic resistance profiles of Shiga toxin-producing Escherichia coli (STEC), Salmonella spp., Shigella spp., and Staphylococcus aureus strains.Materials and methods. 660 samples were collected at two communal kitchens in Hanoi, Vietnam between 2021 and 2022. They included foodstuffs, environmental (food processing tools) and biological ones (swabs from the hands of personnel). The VITEK® 2 Compact system in combination with DNA sequencing was used to identify bacterial species. The antibiotic susceptibility test (AST) was performed according to Kirby-Bauer Disk Diffusion Susceptibility protocol following Clinical & Laboratory Standards Institute (CLSI) method (M100-Ed32).Results and discussion. In total, 53 pathogenic bacterial strains have been detected, including 11 STEC, 24 Salmonella enterica, 9 Shigella sonnei, Shigella flexneri, and 8 S. aureus. AST of STEC has showed the highest resistance rates to tetracycline and chloramphenicol (90.9 %); trimethoprim+sulfamethoxazole (81.8 %); ampicillin, gentamycin and piperacillin (63.6 %). The STEC isolates were susceptible to carbapenem group. Among the Salmonella strains, 50 % demonstrated resistance to ampicillin, followed by tetracycline and piperacillin (45.8 %). Additionally, 25 % were resistant to ticarcillin+clavulanic acid, 20.8 % – to trimethoprim+sulfamethoxazole, and 16.7 % – to chloramphenicol. All Salmonella strains exhibited susceptibility to gentamicin, cefoxitin, imipenem, meropenem, and ceftazidime. AST of Shigella strains revealed the highest resistance rate for tetracycline (30 %), followed by cefazolin and ceftazidime (20 %). However, all Shigella strains were susceptible to cefoxitin, carbapenem groups, and chloramphenicol. Among the S. aureus strains, 50 % exhibited resistance to erythromycin, azithromycin, clindamycin, penicillin, telithromycin, and gentamicin, followed by ciprofloxacin, moxifloxacin, levofloxacin, and chloramphenicol (25 %). All S. aureus strains were still susceptible to trimethoprim+sulfamethoxazole, daptomycin, linezolid, doxycycline, minocycline, and vancomycin. Our findings reflect the current situation on antibiotic resistance among pathogenic bacteria strains circulating at the study sites during food processing. They are an evidence of potential risk of food poisoning. There is a need to undertake the proper containment measures on the part of authorities or policy makers.