Investigation of the food value chain of ready-to-eat chicken and the associated risk for staphylococcal food poisoning in Tshwane Metropole, South Africa

A descriptive cross-sectional study of food hygiene practices among informal ethnic food vendors in Gauteng Province, South Africa

Demand for ethnic foods by the immigrant population has led to proliferation of ethnic food shops (shops selling foods eaten by different ethnic groups). However, the status of the food hygiene practices among these vendors is unknown. This study investigated food hygiene practices among informal ethnic food vendors in Gauteng Province (GP), South Africa. Participants included immigrants managing informal ethnic food shops in GP. Snowball sampling was used to identify participants (n=40). A questionnaire/checklist was used to collect information on hygiene practices. Although majority of ethnic food shops (95%; n=38) operated in permanent structures, just over half (55%; n=22) of these facilities had windows. The remaining 5% (n=2) of the vendors operated from the boot/trunk of cars. None of the participants had a food probe used to monitor the temperature of food. Most of the participants (65%; n=26) did not own freezers, and just above half (55%, n=22) had microwave ovens. Majority (95%; n=38) of the respondents had access to toilet facilities and tap water at their premises. Only two (5%; n=2) respondents brought water from home, and these used public toilets at shopping centers in the vicinity of their businesses. Majority (72.5%; n=29) of the respondents were not aware of the importance of keeping food above 65˚C. Slightly over half (55%, n=22) of the respondents did not reheat the food before serving, and only 10 % (n=4) followed proper food reheating procedures. Poor food hygiene practices and lack of appropriate food handling equipment and facilities are common among ethnic food vendors. The widespread lack of awareness of the importance of holding food above 65˚C, and the high prevalence of not reheating the food before serving, and not following proper food reheating procedures, are a major source of concern as these practices are potentially associated with promoting food contamination with foodborne diseasecausing organisms. It is envisaged that findings reported here can guide policy makers to design policies that promote selling safe food by ethnic food vendors. To enhance compliance, it is recommended that such policies should be user friendly to the operators of informal ethnic food shops.

Scoping review of food safety at transport stations in Africa

OBJECTIVE

The WHO has declared food safety as a public health concern. Transport hubs such as taxi ranks, bus stations and other transport exchange sites are major food trading/purchasing sites, particularly in Africa. Research evidence is needed to improve food safety policies and ensure consumption of safe food, owing to the increasing burden of foodborne diseases, particularly in the WHO Africa Region. We systematically mapped and described research evidence on food safety at transport stations in Africa.

DESIGN

A scoping review guided by the Arksey and O'Malley framework.

DATA SOURCES

We searched for original research articles in PubMed, Web of Science, and EBSCOhost (Academic search complete, CINAHL with Full-text and Health Source), SCOPUS, and Google Scholar from their inception to 25 October 2020.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

We included studies that focused on food safety, involved transport stations, involved African countries and were published in English.

DATA EXTRACTION AND SYNTHESIS

Data extraction was performed by two reviewers using a piloted-tested form. Thematic analysis was used to organise the data into themes and subthemes, and a narrative summary of the findings is presented.

RESULTS

Of the total 23 852 articles obtained from the database searches, 16 studies published in 6 countries met the inclusion criteria. These 16 studies were published between 1997 and 2019, with the most (5) in 2014. Of the 16 studies, 43.8% (7) were conducted in South Africa, 3 studies in Ghana, 2 in Ethiopia and 1 study each in Nigeria, Kenya, Lesotho and Zambia. Most (44.4%) of the included studies focused on microbial safety of food; few studies (22.2%) focused on hygienic practices, and one study investigated the perspective of consumers or buyers. Microbes detected in the foods samples were Salmonella spp, Escherichia coli, Shigella spp, Bacillus sp, Staphylococcus aureus, which resulted mainly from poor hygiene practices.

CONCLUSIONS

There is limited research that focused on food safety at transport stations in Africa, especially on aspects such as hygiene practices, food storage and occupational health and food safety. Therefore, we recommend more research in these areas, using various primary study designs, to inform and improve food safety policies and practices for transport stations in African countries alongside improving access to clean water/handwashing facilities, and undertaking structural changes to facilitate behaviours and monitoring for unintended consequences such as livelihoods of vulnerable populations.

Prevalence, Enterotoxigenic Potential and Antimicrobial Resistance of Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus (MRSA) Isolated from Algerian Ready to Eat Foods

Staphylococcus aureus causes a foodborne intoxication due to the production of enterotoxins and shows antimicrobial resistance, as in the case of methicillin-resistant strains (MRSA). Herein, we analyzed 207 ready-to-eat foods collected in Algeria, reporting a S. aureus prevalence of 23.2% (48/207) and respective loads of coagulase positive staphylococci (CPS) ranging from 1.00 ± 0.5 to 5.11 ± 0.24 Log CFU/g. The 48 S. aureus isolates were widely characterized by staphylococcal enterotoxin gene (SEg)-typing and 16S-23S rDNA intergenic spacer region (ISR)-PCR, as well as by detecting tst and mecA genes, genetic determinants of toxic shock syndrome toxin-1 and methicillin resistance, respectively. We found that the S. aureus isolates belonged to seven different SEg-types harboring the following combinations of genes: (1) selW, selX; (2) egc (seG, seI, seM, seN, seO), selW, selX; (3) seA, seH, seK, seQ, selW, selX; (4) seB, selW, selX; (5) seD, selJ, seR, selW, selX; (6) seH, selW, selX, selY; and (7) seA, egc, selW, selX, while among these, 2.1% and 4.2% were tst- and mecA- (staphylococcal chromosomal cassette mec-type IV) positive, respectively. Selected strains belonging to the 12 detected ISR-types were resistant towards antimicrobials including benzylpenicillin, ofloxacin, erythromycin, lincomycin, tetracyclin, kanamycin, oxacillin, and cefoxitin; 8.3% (1/12) were confirmed as MRSA and 16.7% (2/12) were multidrug resistant. The present study shows the heterogeneity of the S. aureus population in Algerian ready-to-eat foods as for their toxigenic potential and antimicrobial resistance, shedding the light on the quality and safety related to the consume of ready-to-eat foods in Algeria.

Self-Reporting of Risk Pathways and Parameter Values for Foot-and-Mouth Disease in Slaughter Cattle from Alternative Production Systems by Kenyan and Ugandan Veterinarians

Countries in which foot-and-mouth disease (FMD) is endemic may face bans on the export of FMD-susceptible livestock and products because of the associated risk for transmission of FMD virus. Risk assessment is an essential tool for demonstrating the fitness of one’s goods for the international marketplace and for improving animal health. However, it is difficult to obtain the necessary data for such risk assessments in many countries where FMD is present. This study bridged the gaps of traditional participatory and expert elicitation approaches by partnering with veterinarians from the National Veterinary Services of Kenya (n = 13) and Uganda (n = 10) enrolled in an extended capacity-building program to systematically collect rich, local knowledge in a format appropriate for formal quantitative analysis. Participants mapped risk pathways and quantified variables that determine the risk of infection among cattle at slaughter originating from each of four beef production systems in each country. Findings highlighted that risk processes differ between management systems, that disease and sale are not always independent events, and that events on the risk pathway are influenced by the actions and motivations of value chain actors. The results provide necessary information for evaluating the risk of FMD among cattle pre-harvest in Kenya and Uganda and provide a framework for similar evaluation in other endemic settings.

Prevalence, Serovars, and Factors Associated with Salmonella Contamination of Chicken Carcasses Sold in Outlets of the Informal Market in Gauteng Province, South Africa

ABSTRACT

Salmonella has been linked to many foodborne illnesses and epidemics in both humans and animals. This cross-sectional study determined the prevalence, serovars, and factors associated with Salmonella contamination of chickens slaughtered in informal market outlets in Gauteng Province, South Africa. A total of 151 chicken carcasses were randomly collected from 47 outlets. Standard bacteriological and molecular methods were used to isolate, identify, and determine the serovar of Salmonella isolates. The prevalence of Salmonella in carcass swabs, cloacal swabs, and carcass drips was 29.1% (44 of 151), 27.2% (41 of 151), and 43.7% (66 of 151), respectively, and the differences were statistically significant (P = 0.004). Only 5 (township locations of outlet, throughput, carcass evisceration, location of carcass for sale, and outlet sanitation) of 10 factors investigated for the contamination of carcasses by Salmonella were statistically significantly (P < 0.05) associated with the isolation of Salmonella. Of the 268 isolates of Salmonella, 157 (58.6%) were typeable using a limited molecular PCR technique, and nine serovars were identified. The predominant Salmonella enterica serovars were Bovismorbificans (31.0%), Enteritidis (7.5%), and Hadar (6.7%). The five important factors found to be significantly associated with the isolation of Salmonella at these outlets offer opportunities for the reduction of Salmonella contamination. There is a need for further investigation of the probable causes of the predominant isolation of Salmonella serovar Bovismorbificans in chickens and its potential implications for human infections in South Africa. It is concluded that chickens purchased from the informal market in Gauteng Province can be a source for salmonellosis in humans if improperly cooked before consumption.

Antimicrobial Resistance Profiles of Salmonella Isolates on Chickens Processed and Retailed at Outlets of the Informal Market in Gauteng Province, South Africa

The study determined the antimicrobial resistance profiles of Salmonella on chickens processed and retailed at outlets of the informal markets in Gauteng province, South Africa. The study also investigated the relationship of antimicrobial resistant Salmonella to the source and type of samples and their serotypes. Carcass swabs, cloacal swabs and carcass drips were randomly collected from each of 151 slaughtered chickens from six townships. Isolation and identification were performed using standard and polymerase chain reaction (PCR) methods. The disc diffusion method was used to determine the resistance of Salmonella isolates to 16 antimicrobial agents and PCR to determine their serovars. Ninety-eight (64.9%) of the 151 chickens were contaminated with Salmonella of which 94.9% (93/98) were resistant serovars. The frequency of antimicrobial resistance of Salmonella isolates was high to erythromycin (94.9%) and spectinomycin (82.7%) but was low to ciprofloxacin (1.0%) and norfloxacin (1.0%) (p < 0.05). All 170 isolates of Salmonella tested exhibited resistance to one or more antimicrobial agents and the frequency varied significantly (p < 0.05) across the townships, the type of samples and the serovars. The prevalence of multidrug resistance (MDR) in Salmonella was 81.8% (139/170). Our findings pose zoonotic, food safety and therapeutic risks to workers and consumers of undercooked, contaminated chickens from these outlets.

Prevalence and risk of staphylococcal and coliform carcass contamination of chickens slaughtered in the informal market in Gauteng, South Africa

Purpose

The primary objective was to determine the prevalence of indicator microorganisms [Staphylococcus aureus, non-S. aureus staphylococci (NSAS), coliforms and aerobic bacteria] for contamination of chicken carcasses, carcass drip and rinse water from the informal chicken market in Gauteng, South Africa.

Design/methodology/approach

Chicken swabs, chicken drips and rinse waters were collected from 151 chickens from 47 random outlets. Pre-tested questionnaires were administered to capture the risk factors for bacterial contamination. Standard microbiological procedures were conducted for isolation and enumeration of target bacteria.

Findings

NSAS (64% and 41%) and S. aureus (12% and 31%) were prevalent on carcasses and in carcass drip respectively. Coliforms (62%) and aerobic bacteria (85%) were detected in rinse water. Significant risk factors for contamination of carcasses with NSAS, S. aureus and coliform organisms were: evisceration of chickens on the same location used for sale, cleaning of display counter with dirty clothes/wipes, holding of differently sourced chickens in the same cage prior to slaughter, not cleaning the display table/counter and hands at all, washing knives in rinse water, high turnover of daily slaughter and length of time to display chickens.

Research limitations/implications

The limitations of this research were the limited geographical coverage and small sample size.

Practical implications

The isolation of these indicator microorganisms suggests the potential presence of other chicken-borne pathogens not tested for in the study.

Social implications

The findings serve to inform policy on public health and street-vended food and can guide control on good sanitary practices.

Originality/value

This is the first comprehensive report on ready to eat chickens from the informal markets in Gauteng, South Africa.

Antimicrobial Resistance Phenotype of Staphylococcus aureus and Escherichia coli Isolates Obtained from Meat in the Formal and Informal Sectors in South Africa

BACKGROUND

Foodborne diseases (FBD) caused by resistant pathogens are a global public health problem. One main driver of the increasing FBD incidence is the transfer of pathogenic organisms from animal guts to carcasses during processing and subsequent transfer from meat products to consumers.

METHODS

In this study, meat samples from abattoirs in the formal meat sector (FMS) (n = 140) and slaughter points in the informal meat sector (IMS) (n = 104) were collected for microbial detection and phenotypic AMR determination using polymerase chain reaction.

RESULTS

The antibiogram of Staphylococcus aureus isolates revealed that resistance to clindamycin (74.3%) and ampicillin (59.5%) was highest in the FMS, while resistance to penicillin (83.8%) and tetracycline (82.1%) was highest in the IMS. Escherichia coli isolates show significant resistance to chloramphenicol (90.7%) and tetracycline (82.3%) in the FMS. Likewise, resistance to tetracycline (92.3%) and sulfamethoxazole/trimethoprim (87.5%) was highest in the IMS. The multiple antibiotic resistance index (MARI) for S. aureus and E. coli ranged from 0.3 to 0.8 and 0.2 to 0.5, respectively.

CONCLUSION

This study suggests high-level contamination of meat with resistant pathogens and highlights the public health consequences associated with consuming such unhygienic products.

Quantitative versus qualitative risk assessment of meat and its products: what is feasible for Sub-Saharan African countries?

Prevalent risks in meat value-chains of sub-Saharan African (SSA) countries are increasingly attributed to microbial rather than chemical hazards. Resource constraints and lack of capacity has limited the utilization of risk assessment tools in the instituting of food controls to mitigate the risks. The review sought to bring to light the focus of risk assessment studies in SSA while generating evidence of feasible options to further the contribution of this component in risk mitigation. The informal street vending sector emerges as a priority in the meat value chain with a vendor population that are unwilling to abandon it. Campylobacter and Staphylococcus aureus are prevalent risks that have bedeviled this sector. However, limited risk assessment studies with capacity to inform proper food controls for the sector have been done. Evidence in place indicate that the incorporation of qualitative aspects in quantitative approaches serve as less-costly and effective ways of generating risk estimates. Limitations of capacity and gaps in epidemiological data are also circumvented. Considering that the street-vending sector is robust and its dynamics of operation are not fully in the picture of policy actors; incorporation of a participatory approach that combines qualitative and quantitative aspects of risk assessment is highly recommended.

Consumers' perceptions of intrinsic and extrinsic attributes as indicators of safety and quality of chicken meat: Actionable information for public health authorities and the chicken industry

Understanding consumers' perceptions toward chicken meat safety and quality could provide valuable information to public health educators since it is the most consumed meat. This study explores perceptions of a group of South African consumers on the safety and quality of chicken meat based on intrinsic and extrinsic attributes and identifies related safety risks. Data were collected through a web-based survey (863 participants). A substantial proportion of consumers considered supermarkets as the most trusted outlets to sell safe and good quality chicken (compared with butcheries, wholesalers, farmers' markets, street vendors, or "other retailers"). The majority of respondents (53%) most trusted refrigerated chicken to be of good quality compared with 36% trusting frozen chicken or 11% chicken at room temperature. Frozen chicken was considered most safe by 48% of consumers while 43% regarded refrigerated chicken as most safe. At point of purchase and home, smell, use-by date, sell-by date, and color were perceived as important attributes when judging chicken safety and quality. Consumers considered the absence of brine use and growth-promoting hormones in chicken feed as relatively important. The majority of consumers can be classified as highly involved during purchasing. It is essential that consumers apply safe chicken handling practices from point of purchase to consumption, irrespective of the type of retailer, perceived sensory characteristics, and date labels to reduce or eliminate microbial risks. Addressing consumer's knowledge and expectations regarding factors such as growth-promoting hormones and free range may improve safety and quality perceptions. PRACTICAL APPLICATION: This study gives insight into perceptions of a group of South African consumers toward safety and quality of chicken meat. Understanding consumers' perceptions can provide valuable information to public health educators since chicken meat is a common vehicle for Salmonella spp. and Campylobacter spp., which are human pathogens. Additionally, this information can assist the chicken industry to meet consumer expectations.

Prevalence and distribution of antimicrobial resistance determinants of Escherichia coli isolates obtained from meat in South Africa

OBJECTIVE

This study aimed to characterise antibiotics resistance of Escherichia coli isolates from the formal meat sector (FMS) and informal meat sectors (INMS).

METHOD

A total of 162 and 102 E. coli isolates from the FMS, and INMS respectively were isolated by standard culture-based, and biochemical reactions. The isolates were further confirmed by polymerase chain reaction (PCR). The disc diffusion method was used to screen for antimicrobial susceptibility against 19 different antibiotics. The presence of class 1-2 integrons in each E. coli isolates was assessed using 3'-CS and 5'-CS regions specific primers.

RESULT

Among the 19 antimicrobials, resistance to tetracyclines, aminoglycosides, cephalosporins, and nitrofurans were found to be more frequent than carbapenems and chloramphenicol. The number of multi-drug resistance ranged from three to ten antimicrobials. The resistant determinants with the highest prevalence in the FMS and INMS were; [aminoglycosides: aadA (40.6%; 31.9%), and strA (6.5%; 9.4%)], [β-lactams: ampC (20%; 45%),], [Chloramphenicol: catI (1.7%; 1.7%), and [tetracyclines: tetB (11.5%; 24%),], and [sulfonamides: sul1 (22.2%; 26.7%),].

CONCLUSION

Higher phenotypic resistance to cephalosporins and carbapenems were found in the FMS than in INMS. The multiple antibiotic resistance (MAR) indexes for FMS and INMS ranged from 0.2-0.5. The results reveal a high prevalence of multidrug-resistant E. coli isolates and resistance determinants, suggesting that consumers and handlers of such meat are at risk of contracting antibiotic-resistant E. coli-related foodborne disease.

Prevalence and risk factors contributing to antibiotic-resistant Staphylococcus aureus isolates from poultry meat products in South Africa, 2015-2016

Staphylococcus aureus, including methicillin-resistant strains, has been detected in food products of animal origin globally. Limited data have been reported on the factors contributing to antibiotic resistance of food-borne pathogens in South Africa. The primary aim of this study was to determine the prevalence of S. aureus, including antibiotic-resistant strains, in poultry meat products as well as the evaluation of potential risk factors for contamination of poultry meat products with antibiotic-resistant S. aureus isolates. A cross-sectional investigation was conducted in municipalities located across the nine provinces of South Africa, which included abattoirs, meat processing facilities, retail outlets and cold stores at the major ports of entry into South Africa. Staphylococcus aureus isolates obtained from various poultry meat products were tested for susceptibility to 14 antibiotic compounds representing 10 antibiotic classes using the Kirby–Bauer disc diffusion method. Potential risk factors were evaluated using a logistic regression model. Of the 311 samples tested, 34.1% (n = 106) were positive for S. aureus (95% confidence interval [CI], 28.9% – 39.7%). Seventy-two of the 106 isolates were randomly selected for antibiotic sensitivity testing. Twenty-one per cent (n = 15) of the isolates selected for sensitivity testing were methicillin-resistant strains (95% CI, 12.2% – 32.0%). Multi-drug resistance was detected in 22.2% (n = 16) of these isolates tested (95% CI, 13.3% – 33.6%). Origin of the product (p = 0.160), type of meat product (p = 0.962), type of facility (p = 0.115) and facility hygiene practices (p = 0.484) were not significantly associated with contamination of poultry meat products with methicillin-resistant strains. The study provides baseline data for further studies on antibiotic resistance risk assessments for food-borne pathogens, including S. aureus, which should guide the implementation plans of the South African National Antimicrobial Resistance Strategy Framework, 2017–2024.

Aerobic Mesophilic, Coliform, Escherichia coli, and Staphylococcus aureus Counts of Raw Meat from the Formal and Informal Meat Sectors in South Africa

Foodborne disease (FBD) is a global public health concern, and foods from animal sources have been associated with outbreaks of food-related illness. In this study, animal carcasses from the two abattoirs (HT1 and HT2) in the formal meat sector (FMS) and slaughter points in the informal meat sector (INMS) were examined at two stages of slaughter (before washing and after washing) for aerobic colony counts (ACC) and total viable count (TCC), as well as Escherichia coli and Staphylococcus aureus count. At each stage, carcasses were sampled by swabbing at the neck, brisket, flank, and rump. ACC for beef, mutton, and pork carcasses at HT1 and HT2 before washing were between 2.5–5.8, 2.2–4.7, and 2.7–3.7 mean log CFU/cm², respectively, and TCC count before washing was highest on the neck of cattle (6.3 ± 2.4) and after washing was highest on the perineal of sheep (5.7 ± 6.9). In the INMS, TCC count was highest on the brisket (6.9 ± 3.2) and in the neck (5.5 ± 2.4). Higher ACC values of 6.2–6.7 mean log CFU/cm² were obtained in the INMS. The highest count for E. coli (4.2 mean log CFU/cm²) after washing was in the neck, while the highest count for S. aureus (4.0 mean log CFU/cm²) was in the flank. All bacteria count in the INMS exceeded acceptable limits, and washing did not significantly reduce microbial load in meat in the FMS and INMS. Bacteria count in the FMS and INMS exceeded acceptable standards. However, meat processed in the INMS poses a more significant risk of FBD to consumers.

Occurrence, Virulence Factors, Antimicrobial Resistance, and Genotyping of Staphylococcus aureus Strains Isolated from Chicken Products and Humans

Staphylococcus aureus in food is a consequence of inadequate hygienic handling and processing, posing a potential risk to public health. The current study aimed to characterize virulence factors, as well as antimicrobial resistance of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) isolated from retail chicken products and hand swabs from vendors in Egypt. In addition, genetic relatedness of the isolates from chicken and humans was evaluated by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using protein A as a target. A total of 110 samples were collected from chicken products (n = 80) and vendors (n = 30). Overall, 30 (37.5%) chicken products samples were positive for S. aureus, whereas hand swabs from meat handlers revealed that 18 (60%) were positive. Ten MRSA strains were characterized by the presence of the mecA gene, comprising seven isolates from chicken and three from humans. Virulence-associated factors were evaluated by PCR, revealing that 31.3% of S. aureus isolates harbored the Panton-Valentine leukocidin (PVL) gene, whereas 10.4% were positive for the sea and sed genes each, and only two isolates were positive for γ-hemolysin-associated gene. Genotyping using spa PCR-RFLP showed identical restriction banding patterns of MRSA isolates of human and chicken meat origin, indicating the genetic relatedness of the isolates. To the best of our knowledge, this is the first study to characterize PVL-positive MRSA from chicken products and to utilize spa-RFLP for evaluating the genetic relatedness between MRSA of human and chicken origin in Egypt.