Microbial quality of goat carcasses in Lilongwe, Malawi

Abstract

BackgroundA study to evaluate the microbial quality of goat carcasses at Chinsapo-2 and Chigwirizano slaughter slabs in Lilongwe District, Malawi, was conducted in June 2014. A total of 154 swab samples were collected from 34 carcasses for identification of the isolates and bacterial total viable counts (TVCs). Cotton swab samples were also collected from clothes, knives and hands of butchers and water used in the slaughter process.ResultsThe study found that predominant bacterial isolates at Chinsapo-2 were E. coli (29%), followed by Bacillus spp. (18%), Proteus spp. (15%) and Klebsiella spp. (13%). On the other hand, bacterial isolates from Chigwirizano were E. coli (38%), followed by Bacillus spp. (23%), Proteus spp. (13%) and Klebsiella spp. (5%). The mean bacterial TVC before treatment (washing hands, clean knives with hot water and provision of working gear) for Chinsapo-2 were 6.74 ± 0.38, 6.38 ± 0.38 and 8.26 ± 0.38, while Chigwirizano had 9.48 ± 0.50, 9.48 ± 0.50 and 8.24 ± 0.50 log10 CFU/cm2. After treatment, Chinsapo-2 recorded 8.03 ± 0.38, 7.67 ± 0.38 and 7.30 ± 0.38 log10 CFU/cm2 on hands, knives and clothes while Chigwirizano had 7.12 ± 0.50, 8.84 ± 0.50 and 8.73 ± 0.50 log10 CFU/cm2, respectively. Washing hands with tap water before slaughter significantly (P < 0.05) reduced bacterial load on the hands of workers at Chigwirizano and not at Chinsapo who used shallow well water. Mean TVCs for flanks, fore leg, brisket and rump for Chinsapo-2 were 7.17 ± 0.38, 5.98 ± 0.38, 5.74 ± 0.38 and 5.63 ± 0.38 log10 CFU/cm2, respectively, before treatment. After treatment, Chinsapo-2 had 6.97 ± 0.38, 5.75 ± 0.38, 6.27 ± 0.38 and 5.90 ± 0.38 log10 CFU/cm2. On the other hand, before treatment, Chigwirizano recorded 6.34 ± 0.50, 5.83 ± 0.50, 5.75 ± 0.50 and 6.40 ± 0.50 log10 CFU/cm2 and after treatment the log10 CFU/cm2 were 8.22 ± 0.50, 6.43 ± 0.50, 6.17 ± 0.50 and 6.94 ± 0.50 on the four carcass sites.ConclusionsThe study revealed that the level of contamination on goat carcasses in Lilongwe was extremely high exceeding the acceptable international standards for swab values which are <2.8 log CFU/cm2 for TVC, and the unacceptable values are >4.3 log CFU/cm2. Therefore, further studies should be conducted to reduce the bacterial contamination.Graphical abstractRelative frequencies at Chinsapo and Chigwirizano slaughter slabs