Author : Tolentino, Randolph B.

Summary : In this cross-sectional study, 208 raw buffalo milk samples were randomly collected at five sampling sites consisting of three dairy collection centers and two dairy buffalo farms in Nueva Ecija, Philippines. Raw buffalo milk samples were screened for residues of commonly used antibiotics in dairy production in the province, particularly beta lactams, enrofloxacin, and oxytetracycline using enzyme-linked immunosorbent assay (ELISA). Isolates of Staphylococcus aureus and Escherichia coli were also recovered from milk samples and the phenotypic antimicrobial resistance profiles were determined using Kirby-Bauer disk diffusion assay. In addition, interview on the knowledge, attitude, practices, and skills was conducted to characterize the social aspects of dairy buffalo farmers in relation to antibiotic residues on milk and its consequences.

The prevalence of antibiotic residues on dairy buffalo milk in Nueva Ecija, Philippines was observed at 35.42%. The study observed that beta lactam antibiotics (58.17%) were present in majority of the milk samples. However, the amount of residues detected in the study were within the permissible level of the Maximum Residue Limit (MRL) of the Codex Alimentarius.

One hundred twenty-two (122) isolates of S. aureus were recovered from 30 raw milk samples and isolates were resistant to penicillin G (85.71%), oxacillin (81.25%), cefoxitin (26.79%), and oxytetracycline (0.89%). In addition, 233 isolates of E. coli recovered from 78 raw milk samples were observed to have resistance to oxytetracycline (16.31%), cefoxitin (1.29%), and enrofloxacin (0.43%).

Survey of the knowledge, attitude, practices, and skills showed that the knowledge of majority of dairy buffalo farmers was high, their desirable attitude was favorable, their dairy practices good, and their skills ranged from excellent to good concerning avoidance of antibiotic residue in milk in Nueva Ecija, Philippines.

This study determined that raw buffalo milk from Nueva Ecija, Philippines are safe and fit for consumption with regard to antibiotic residue level. In addition, antibiotic residue is not a major concern in the area and the potential transmission of antibiotic resistant bacteria from dairy production need to be evaluated.