Antibiotic Resistant Bacteria in Raw Chicken Meat Sold in a Public Market in Quezon City, Philippines

Abstract

Background: The existence of antibiotic resistant strains of bacteria in both the hospital and community settings is a threat that can plague humanity. There are now increasing evidences that even livestocks for human consumption harbor antibiotic resistant bacteria. To date, there is a limited information on the presence of antibiotic resistant bacteria isolated from raw food, particularly from chicken, for human consumption in the Philippines.

Objective: This study aimed to determine the presence of antibiotic resistant bacteria from raw chicken meat sold in a public market in Quezon City, Philippines.

Methodology: Twenty-five raw chicken meats (leg part) were purchased from randomly selected stalls in a public market. Selective and differential media were used to isolate Escherichia. coli, Salmonella spp., and Staphylococcus aureus from the purchased poultry meat. The isolated bacteria were subjected to several morphological and biochemical tests, to confirm their identities. Twenty-five colonies from each of the three isolated genera were selected to be used in the antibiotic susceptibility screening using the Kirby-Bauer disk diffusion method.

Results: This study confirms the presence of antibiotic resistant strains of Escherichia. coli, Salmonella spp., and Staphylococcus aureus from raw chicken legs bought in a public market. In the disc diffusion method, 100% of the isolated E. coli were resistant to amoxicillin, ampicillin, penicillin, clindamycin; 96% were resistant to erythromycin, 92% to clarithromycin, and 20% to tetracycline. For the isolated Salmonella spp., 100% were also resistant to amoxicillin, ampicillin, penicillin, clindamycin; 96% were resistant to clarithromycin, and 16% were resistant to ciprofloxacin. Of the 25 isolates of S. aureus, 100% were also resistant to amoxicillin, ampicillin, penicillin, tetracycline; 20% were resistant to clarithromycin and chloramphenicol; 16% were resistant to clindamycin and norfloxacin; and 12% were resistant to erythromycin.

Conclusion: The presence of antibiotic resistant E. coli, Salmonella spp., and S. aureus in animal food sold at a public market in Quezon City to not just one antibiotic but more, may pose a serious threat to human health. The livestock industries should also look into the use of antibiotics for nontherapeutic purposes, since these animals can also lead to the emergence of antibiotioc resistant bacteria that can be transferred to humans when they are consumed as food or by direct contact with the farm animals. Therefore, vigilant monitoring and stricter policies and regulations must be implemented on the use and marketing of antibiotics in food animals to ensure food safety in the Philippines.