THE EXISTING STATE OF MICROBIOLOGICAL MEAT SAFETY IN ETHIOPIAN ABATTOIRS AND BUTCHER SHOPS: PREVALENCE AND IDENTIFICATION OF SALMONELLA ENTERICA SEROTYPES, SAFETY INDICATORS, AND DEVELOPMENT OF MITIGATION TOOLS

Abstract

Foodborne disease is a major global public health concern. Animal source foods are the leading point of exposure for foodborne pathogens. Salmonella enterica is one of the main meat safety challenges due its ability to colonize and persist on facilities including meat contact surfaces. Meat handling practices with the lack of appropriate knowledge on food safety and workers’ behaviors at abattoirs and butcher shops attribute to contamination of meat and its risk of safety. Therefore, this study was intended to find out the existing microbial safety status of meat (Meta analysis vs. laboratory investigation); phenotypic antimicrobial resistances profiles of isolated pathogens, food safety knowledge, attitudes and hygienic practices (KAP) of workers in meat chain and to design appropriate meat safety challenge mitigation intervention. Consequently, a systematic literature review and meta-analysis was conducted from major electronic databases using indexing services including PubMed/MEDLINE, Google Scholar, Science Direct and WorldCat. The pooled prevalence estimate and antimicrobial resistance profiles of the bacterial pathogens of public health importance such as Samonella spp., E. coli O157:H7, L. monocytogens and Staphylococcus spp. were determined from meat chain in Ethiopia. The study protocol was registered on PROSPERO. A cross-sectional study design was also used to assess knowledge on food safety, attitudes, and hygienic practices of workers in abattoirs and butcher shop facilities. A food safety questionnaire was administered to 542 respondents selected from abattoirs (n=422) and butcher shops (n = 120). Additionally, various samples from abattoirs (n= 150 beef carcasses; 450 sub-swab samples) and butcher shops (n= 360) were collected for microbiological analysis. Detection and identification of S. enterica were carried out using Wellcolex™ color Salmonella rapid latex agglutination kit and finally the presence of invA gene in presumptive positive isolates were confirmed by Real-Time PCR. All Salmonella enterica serotypes were phenotypically evaluated for susceptibility to a panel of 13 antimicrobials using the disk diffusion method as described in Clinical and Laboratory Standards Institute guidelines. The hygiene indicator bacteria were detected and quantified after growth onto petrifilms. Lastly, training intervention using one-group pretest-posttest design was employed to enable them xxiv assess on process hygiene, workers’ knowledge in food safety and behaviors in Addis Ababa and Hawasssa Municipal Abattoirs. Eligible 114 pre-intervention and 108 post-intervention participants were engaged in the study. A total of 138 swab samples (69 pre-intervention and 69 post intervention) were collected from beef carcasses, equipment, environment and personnel to determine the levels of hygiene indicator bacteria of the generic E. coli (ECC), Coliform (CC), Total Coliform (TCC), enterobacteriaceae (EB) and Aerobic Plate Count (APC). The results of systematic review and meta-analysis indicated that a total of 27 original studies with 7828 meat samples were conducted in Ethiopia. When subjected to systematic review and meta-analysis, the pooled prevalence of L. monocytogenes, E. coli O157:H7, Salmonella spp., Staphylococcus spp. was 4%, 5%, 9%, and 21%, respectively. The sample sources showed a high Salmonella prevalence in abattoirs (6%), butcher shops (36%) and markets (11%). The E. coli O157:H7 prevalence in abattoirs, butcher shops and markets was 5, 6 and 8%, respectively. The bacterial isolates showed different antimicrobial resistance profiles against the tested drugs. About 25% of Salmonella spp. and 10% of E. coli 157:H7 isolates were found to be resistant to ampicillin and ceftriaxone, respectively. The results of this study also revealed that 63.3% and 55.8% of the respondents from abattoirs and butcher shops, respectively, demonstrated poor meat safety knowledge. About 46% of the respondents demonstrated good attitude towards meat safety in abattoirs. The respondents from abattoirs (61%) and butcher shops (65%) were classified as having good practices towards meat safety. Logistic regression analysis showed that abattoir workers with primary school education (AOR = 28.93, 95% CI = 16.14 to 51.85) and informal education (AOR = 39.95, 95% CI = 9.19 to 173.70) were more likely to have poor meat safety knowledge (P < 0.0001). The respondents with primary school education (AOR = 13.28, 95% CI = 1.728 to 101.97, P = 0.013) and informal education (AOR = 74.86, 95% CI = 9.05 to 619.22, P < 0.0001) were more likely to have poor attitude toward food safety. Respondents with informal education (AOR = 7.88, 95% CI = 2.56 to 24.25), contract employee status (AOR = 10.86, 95% CI = 5.09 to 23.17), < 2 years of work experience (AOR = 2.50, 95% CI = 1.132 to 5.51, P = 0.023) and poor knowledge (AOR = 3.07, 95% CI = 1.59 to 5.95, P = 0.001) were more likely to have poor food safety practice. The prevalence S. enterica on beef carcasses was 22.7% (95% CI, 16.0 - 30.0) in abattoirs and 16.7% (95% CI, 8.3 – 26.7) in butcher shops. Further study in abattoirs indicated that the prevalence of S. enterica on hides was 13.3% (95% CI, 8.0 - 18.7), pre-evisceration was 12.0% (95% CI, 7.3 - 17.3), and post-evisceration was 4.7% xxv (95% CI, 1.3 - 8.0). The prevalence of S. enterica was significantly lower in post evisceration samples compared to hides (P = 0.009) and pre-evisceration (P = 0.022). A total of five Salmonella enterica serotypes including Salmonella enterica serotype anatum, Salmonella enterica serotype hadar, Salmonella enterica serotype dublin, Salmonella enterica serotype typhimurium and Salmonella enterica serotype choleraesuis were identified from abattoirs and butcher shops in which Salmonella enterica serotype anatum was the most dominant. The prevalence of S. enterica serotype in abattoirs was the highest during wet season (P = 0.011). No significant difference was detected in the prevalence of S. enterica between abattoirs (P = 0.346), and among butcher shop location (P = 0.806). In abattoirs, the overall mean log CFU/cm2 ± SD of generic E. coli, coliform and total coliform counts were 4.55±0.99, 4.91±1.13 and 4.98±1.09, respectively. In butcher shop facilities, the overall mean ± SD (log CFU/cm2 ) of ECC, CC, TCC, EB and APC were 4.31 ± 1.15, 4.61 ± 1.33, 4.77 ± 1.32, 4.59  1.38, and 5.87  1.5. In abattoirs, about 20% of S. enterica were phenotypically multi drug resistant. In butcher shops, (80%) of S. enterica isolates were susceptible to the panel of 11 out of 13 antimicrobials tested. The participant’s food safety knowledge scores on hygienic practices (P = 0.009), pathogens and its associated illness (P = 0.004) significantly increased after intervention. The contamination level of generic E. coli (P = 0.034) and Enterobacteriaceae (P = 0.046) were significantly decreased after intervention. This study revealed a high meat contamination level of indicator bacteria organisms suggesting the existence of poor hygienic practices along the meat supply chain continuum. The presence of S. enterica serotypes on beef with multidrug resistance to commonly used antibiotics may show a public health care challenge. Therefore, integrated intervention approach, standard practical operation protocol for abattoirs and butcher shops, enforcement of food safety standards, swift food safety inspection, refresher trainings and strict meat safety monitoring are recommended in Ethiopian meat supply chain