Microbiological quality of free-range chicken carcasses from a non-regulated slaughter facility in Kenya

Abstract

This study assessed the microbiological quality of meat from free rage-produced chicken processed in an informal slaughter facility. The total viable counts (TVC), total coliform counts, coagulase positive Staphylococcus aureus, Streptococcus species, Salmonella species and Campylobacter species were used as indicators. A cross-sectional sampling of chicken carcasses at informal slaughter facility was carried out. Whole carcass rinse fluid was prepared from 40 randomly obtained freshly dressed carcasses. Fluid samples were cultured in selective media to isolate and enumerate the specific bacteria. S. aureus was further identified by coagulase test, Streptococci by serotyping into Lancefield groups, Campylobacter by DNA analysis and Salmonella by biochemical tests and serology. Bacterial concentrations in the carcasses were calculated as colony forming units (CFU) per ml and CFU/cm2. The mean carcass CFU/ml concentration was 1.59 × 107, 1.44 ×105, 3.2 × 104 and 1.06 × 104 for TVC, Coliforms, S. aureus and Streptococci, respectively. All the mean concentration values were higher than the limits recommended by the Codex Alimentarius Commission (CAC). Coagulase-positive Staphylococcus was isolated from 12 (30%) carcasses and Streptococci from 35 (87%). Majority Streptococci were Lancefield Group D (48.57%) followed by Group G (17.14%), and Group F (14.28%). Campylobacter genus was identified in 11 carcasses (27.5%) and Campylobacter jejuni in three (7.5%). On the other hand, Salmonella was not isolated from any carcass. The results of the study indicated that the low hygienic standard in non-regulated slaughter houses exposed the chicken meat to microbial contaminants which may pose a risk to the consumers. Improvement of slaughter infrastructure and capacity-building of slaughter personnel is therefore critically required to ensure food safety and enable access to high value markets. Key words: Slaughter, free-range chicken, bacterial quality.