Prevalence of Salmonella in raw animal products in Ethiopia: a meta-analysis

Prevalence and Antimicrobial Resistance of Escherichia coli O157:H7 and Salmonella, and the Prevalence of Staphylococcus aureus in Dairy Cattle and Camels under Pastoral Production System

Escherichia coli O157:H7, Salmonella and Staphylococcus aureus are common foodborne pathogens. We determined the prevalence of E. coli O157:H7 and Salmonella in feces and milk and the prevalence of S. aureus in milk from dairy cattle and camels in the Borana pastoral community in the Southern Oromia Region of Ethiopia. Paired individual cow composite (pooled from all quarters in equal proportions) milk and fecal samples were collected from cows (n = 154) and camels (n = 158). Samples were cultured on bacterial isolation and identification media. E. coli O157:H7 and Salmonella isolates were further tested for susceptibility against nine antimicrobial drugs. Different risk factors associated with hygienic milking practices were recorded and analyzed for their influence on the prevalence of these bacteria in milk and feces. The prevalence of E. coli O157:H7 and Salmonella in feces were 3.9% and 8.4%, respectively, in cows, and 0.6% and 2.5%, respectively, in camels. E. coli O157:H7 and Salmonella were detected in the composite milk samples of 2.6% and 3.9% of the cows, respectively, and 0% and 1.3% of the camels, respectively. S. aureus was detected in composite milk samples of 33.4% of the cows and 41.7% of the camels. All E. coli O157:H7 (n = 11) and Salmonella (n = 25) isolates from both animal species and sample types were resistant to at least one antimicrobial drug. Multidrug resistance was observed in 70% (7/10) of the E. coli O157:H7 fecal and milk isolates from cows and 33.3% (2/6) of the Salmonella fecal and milk isolates from camels. The prevalence of these bacteria in feces and milk was not affected by risk factors associated with milking practices. Given the very close contact between herders and their animals and the limited availability of water for hand washing and udder cleaning, these bacteria are most likely present in all niches in the community. Improving community awareness of the need to boil milk before consumption is a realistic public health approach to reducing the risk of these bacteria.

Prevention and Control of Human Salmonella enterica Infections: An Implication in Food Safety

Salmonella is a foodborne zoonotic pathogen causing diarrhoeal disease to humans after consuming contaminated water, animal, and plant products. The bacterium is the third leading cause of human death among diarrhoeal diseases worldwide. Therefore, human salmonellosis is of public health concern demanding integrated interventions against the causative agent, Salmonella enterica. The prevention of salmonellosis in humans is intricate due to several factors, including an immune-stable individual infected with S. enterica continuing to shed live bacteria without showing any clinical signs. Similarly, the asymptomatic Salmonella animals are the source of salmonellosis in humans after consuming contaminated food products. Furthermore, the contaminated products of plant and animal origin are a menace in food industries due to Salmonella biofilms, which enhance colonization, persistence, and survival of bacteria on equipment. The contaminated food products resulting from bacteria on equipment offset the economic competition of food industries and partner institutions in international business. The most worldwide prevalent broad-range Salmonella serovars affecting humans are Salmonella Typhimurium and Salmonella Enteritidis, and poultry products, among others, are the primary source of infection. The broader range of Salmonella serovars creates concern over multiple strategies for preventing and controlling Salmonella contamination in foods to enhance food safety for humans. Among the strategies for preventing and controlling Salmonella spread in animal and plant products include biosecurity measures, isolation and quarantine, epidemiological surveillance, farming systems, herbs and spices, and vaccination. Other measures are the application of phages, probiotics, prebiotics, and nanoparticles reduced and capped with antimicrobial agents. Therefore, Salmonella-free products, such as beef, pork, poultry meat, eggs, milk, and plant foods, such as vegetables and fruits, will prevent humans from Salmonella infection. This review explains Salmonella infection in humans caused by consuming contaminated foods and the interventions against Salmonella contamination in foods to enhance food safety and quality for humans.

Effect of Eugenol, Vanillin, and β-Resorcylic Acid on Foodborne Pathogen Survival in Marinated Camel Meat

The combined inhibitory effect of essential oils (EOs) with meat-based marinades has not been fully studied. Therefore, the present study aimed to gauge the effect of a yogurt-based marinade when individually combined with three EOs, namely eugenol (EU), vanillin (VA), or β-resorcylic acid (BR) on camel meat cubes inoculated with Listeria monocytogenes, Salmonella spp., and Escherichia coli O157:H7 during storage. Fresh camel meat cubes of 10 g were inoculated with bacteria and dipped in the mixture of marinade and EO. Overall, the study had six EO treatments (EU 0.5%, EU 1%, VA 0.5%, VA 1%, BR 0.5%, and BR 1%) and two controls (meat without marinade and marinated meat). Treated meat cubes were stored at 4°C or 10°C for 1, 4, and 7 d. Adding only marinade to the camel meat at 10°C decreased the pathogens by 0.8-2.4 log CFU/g. At 10°C, BR decreased L. monocytogenes, E. coli O157:H7, and Salmonella spp. by 2.0, 1.5, and 1.3 log CFU/g, while EU caused a decrease (p < 0.05) of 1.9, 1.2, and 0.9 log CFU/g, respectively. Similarly, VA caused a reduction in these microorganisms of 1.3, 1.1, and 1.0 log CFU/g, respectively (p < 0.05). The combination of marinade and EO resulted in a decrease of the pathogens ranging from 0.9-1.4 and 2.8-3.7 log CFU/g at 4 and 10°C, respectively. The antimicrobial efficacy of EO alone or when combined with marinade was higher at 10°C than at 4°C with all three pathogens at both 0.5% and 1%. Overall, EOs were found to enhance the microbial safety of camel meat. In addition, they are antimicrobials that occur naturally, require a minimum investment, and may prove to be a great asset for marinated camel meat producers.

Prevalence and associated risk factors for Salmonella enterica contamination of cow milk and cottage cheese in Ethiopia

Animal sourced foods, such as dairy products, are common sources of Salmonella enterica, a foodborne pathogen of increasing global concern, particularly in developing countries. In Ethiopia, most data on the prevalence of Salmonella in dairy products is highly varied and limited to a specific region or district. Furthermore, there is no data available on the risk factors for Salmonella contamination of cow milk and cottage cheese in Ethiopia. This study was therefore conducted to determine the presence of Salmonella throughout the Ethiopian dairy value chain and to identify risk factors for contamination with Salmonella. The study was carried out in three regions of Ethiopia, including Oromia, Southern Nations, Nationalities and Peoples, and Amhara during a dry season. A total 912 samples were collected from milk producers, collectors, processors, and retailers. Samples were tested for Salmonella using the ISO 6579-1: 2008 method, followed by PCR confirmation. Concurrent with sample collection, a survey was administered to study participants to identify risk factors associated with Salmonella contamination. Salmonella contamination was highest in raw milk samples at the production (19.7%) and at milk collection (21.3%) levels. No significant difference in the prevalence of Salmonella contamination among regions was detected (p > 0.05). Regional differences were apparent for cottage cheese, with the highest prevalence being in Oromia (6.3%). Identified risk factors included the temperature of water used for cow udder washing, the practice of mixing milk lots, the type of milk container, use of refrigeration, and milk filtration. These identified factors can be leveraged to develop targeted intervention strategies aimed at reducing the prevalence of Salmonella in milk and cottage cheese in Ethiopia.

Bacteriological quality and antimicrobial susceptibility profiles of isolates of ready-to-eat raw minced meat from hotels and restaurants in Arba Minch, Ethiopia

In Ethiopia, the bacteriological quality of ready-to-eat raw meat is of a great public health concern as it can serve as a source of meat-borne pathogens and worsen the transmission of antimicrobial resistant bacteria, and hence this cross-sectional study, done on 257 meat samples (ie., 169 beef, 50 mutton and 38 chevon) from randomly selected hotels and restaurants (n = 52). Approximately 25 gm of meat samples were taken bi-weekly and subjected to quantitative and qualitative analyses; antimicrobial susceptibility tests were done as per the Kirby-Bauer disk diffusion method. It was found that 13.2 (n = 34), 17.5 (n = 45) and 21.8% (n = 56) samples exceeded the permissible limit for total viable and coliform and S. aureus counts, respectively. At the same time, 24.9% (n = 64) surpassed the bacteriological limit permissible for consumption. Overall, 36.6% (n = 94) of samples were extrapolated as unsatisfactory for consumption due to high bacterial load and or the presence of pathogens. Five different bacterial spp. such as E. coli 65% (n = 167), S. aureus 59% (n = 152), Salmonella spp. 28.4% (n = 73), Campylobacter spp. 14.4% (n = 37) and Shigella spp. 4.3% (n = 11) were isolated in varied proportions. Alarmingly, 60% (n = 264) of the isolates were multi-drug resistant and 51% of S. aureus were found to be MRSA.

Seroprevalence of pullorum disease in chicken across mainland China from 1982 to 2020: A systematic review and meta-analysis

Pullorum disease (PD), caused by the bacterium Salmonella pullorum, severely threatens the health of chickens worldwide, especially in China, and generating concerns for public health safety. Greater awareness of the seroprevalence may facilitate the prevention and control of this disease. We conducted systematic review and meta-analysis on the seroprevalence of PD in chicken flocks across mainland China. The results show that the overall pooled estimates of PD seroprevalence in chicken flocks was 18.2%. Furthermore, during 38-year period the seroprevalence of PD was markedly high in all seven regions, being at least 14.9% in central China. Our results suggest PD was highly prevalent in autumn, followed by winter. Chickens older than 120 days (22.6%, CI₉₅: 14.5%-31.9%) had a significantly higher positive rate of PD than those <120 days in age (9.4%, CI₉₅: 3.7%-17.4%). Additionally, the rearing mode used is a risk factor associated with the seroprevalence of PD, it being considerably lower for caged chickens (13.7%, CI₉₅: 7.1%-22.0%) than free-range chickens (30.4%, CI₉₅: 17.3-45.4%). Our findings demonstrate that PD still poses a major threat to poultry industries in mainland China, and therefore comprehensive and stringent strategies are needed to prevent and control this disease.

Magnitude and Antimicrobial Susceptibility Profile of Salmonella Recovered from Export Abattoirs Located in East Shewa, Ethiopia

Background

Objective

Methods

Results

Conclusion

Health and economic burden of foodborne zoonotic diseases in Amhara region, Ethiopia

Diseases from food of animal origin are common health problems in Ethiopia. A cross-sectional study was carried out to estimate health and economic burden, and to identify demographic factors associated with community awareness of foodborne zoonotic diseases in Amhara region, Ethiopia. Data was collected from 435 households in three towns: Gondar, Lalibela and Debark. A retrospective data was also collected from health records in each town. The health burden due to zoonotic diseases was estimated at 0.2, 0.1 and 1.3 DALYs per household per year and at 73.2, 146.6 and 1,689.5 DALYs out of 100,000 populations per year in Gondar, Lalibela and Debark, respectively. The overall health burden due to foodborne zoonotic diseases (aggregated over the 435 households in the three towns) was estimated to be 89.9 DALYs per 100,000 populations per year. The economic impact of foodborne zoonotic diseases in the three towns of Amhara regional state was 278.98 Ethiopian Birr (ETB) (1ETB = 0.025 US Dollar) per household per year and 121,355.68 ETB per year. Costs of preventive measures followed by costs of patients’ time made the highest contribution while costs of diagnosis made the lowest contribution to the total economic burden of foodborne zoonotic diseases. From a total of 435 respondents, 305 (70.1%) had known the presence of zoonotic diseases. Level of education, number of families in the house and income were highly associated with awareness of zoonosis. Although majority of respondents had known zoonotic diseases exists (70.1%) and disease can be acquired from animal source food (63.2%), the health and economic burden associated to foodborne zoonotic diseases are still high. Therefore, changing mindset and practical training aiming in controlling foodborne zoonotic diseases may be suggested to the community in the health improvement extension service.

Prevalence and epidemiological distribution of selected foodborne pathogens in human and different environmental samples in Ethiopia: a systematic review and meta-analysis

Bacterial Foodborne Pathogens (FBP) are the commonest cause of foodborne illness or foodborne diseases (FBD) worldwide. They contaminate food at any stages in the entire food chain, from farm to dining-table. Among these, the Diarrheagenic Escherichia coli (DEC), Non typhoidal Salmonella (NTS), Shigella spp. and Campylobacter spp. are responsible for a large proportion of illnesses, deaths; and, particularly, as causes of acute diarrheal diseases. Though existing studies indicate the problem may be severe in developing countries like Ethiopia, the evidence is commonly based on fragmented data from individual studies. A review of published and unpublished manuscripts was conducted to obtain information on major FBP and identify the gaps in tracking their source attributions at the human, animal and environmental interface. A total of 1753 articles were initially retrieved after restricting the study period to between January 2000 and July 2020. After the second screening, only 51 articles on the humans and 43 on the environmental sample based studies were included in this review. In the absence of subgroups, overall as well as human stool and environmental sample based pooled prevalence estimate of FBP were analyzed. Since, substantial heterogeneity is expected, we also performed a subgroup analyses for principal study variables to estimate pooled prevalence of FBP at different epidemiological settings in both sample sources. The overall random pooled prevalence estimate of FBP (Salmonella, pathogenic Escherichia coli (E. coli), Shigella and Campylobacter spp.) was 8%; 95% CI: 6.5-8.7, with statistically higher (P <  0.01) estimates in environmental samples (11%) than in human stool (6%). The subgroup analysis depicted that Salmonella and pathogenic E. coli contributed to 5.7% (95% CI: 4.7-6.8) and 11.6% (95% CI: 8.8-15.1) respectively, of the overall pooled prevalence estimates of FBD in Ethiopia. The result of meta-regression showed, administrative regional state, geographic area of the study, source of sample and categorized sample size all significantly contributed to the heterogeneity of Salmonella and pathogenic E. coli estimates. Besides, the multivariate meta- regression indicated the actual study year between 2011 and 2015 was significantly associated with the environmental sample-based prevalence estimates of these FBP. This systematic review and meta-analysis depicted FBP are important in Ethiopia though majority of the studies were conducted separately either in human, animal or environmental samples employing routine culture based diagnostic method. Thus, further FBD study at the human, animal and environmental interface employing advanced diagnostic methods is needed to investigate source attributions of FBD in one health approach.

Carriage, Risk Factors, and Antimicrobial Resistance Patterns of Salmonella Isolates from Raw Beef in Jimma, Southwestern Ethiopia

Purpose

Consumption of raw beef infected with multidrug-resistant Salmonella is pertinent to the world public health risk of antimicrobial resistance. Henceforth, this study aimed to investigate the carriage, antimicrobial resistance (AR) patterns, and the revealing risk factors of Salmonella-contaminating beef in abattoirs and butcher shops in Jimma town.

Methods

A cross-sectional study was conducted to investigate the carriage and AR patterns and to reveal the risk factors of beef contaminated by Salmonella spp. Three hundred and forty-eight swab samples were collected from abattoirs (n=210) and butcher shops (n=138) and the conventional cultural methods were employed for identification of Salmonella. Isolates were subjected to 12 antimicrobials using the Kirby-Bauer disk diffusion method for AR patterns.

Results

The occurrence of Salmonella isolates from the abattoir samples was 11.4%, whereas about 6.52% of isolates were recovered from butcher shops. Educational status (abattoir: odds ratio (OR)=8.40, confidence interval (CI)=1.186-59.493; butcher shops: OR=9.17, CI=1.15-73.239), job related training (abattoir: OR=5.50, CI=1.065-28.416), contamination risk perception (abattoir: OR=5.31, CI=1.256-22.489), neatness of knives (abattoir: OR=7.6, CI=0.892-65.376), source of contamination (abattoir: OR=8.44, CI=1.682-42.39), wearing of protective cloth (butcher shops: OR=8.44, CI=1.682-42.39), manner of hand washing (butcher shops: OR=7.25, CI=1.210-43.442), and money handling (butcher shops: OR= 9.69, CI=1.578-59.474) were among the potential risk factors significantly associated with Salmonella carcass contamination in the abattoir and butcher shops. Of the 33 Salmonella isolates, 14 (58.3%) and six (66.7%) of the abattoir and butcher shops isolates, correspondingly, were resistant to two or more antibiotics.

Conclusion

The finding of this investigation exhibited extensive multidrug-resistant Salmonella isolates in the study setting. Hence, establishing standard meat safety requirements and provision of training for meat handlers and prudent use of antimicrobials are recommended.

Lactobacillus casei protects intestinal mucosa from damage in chicks caused by Salmonella pullorum via regulating immunity and the Wnt signaling pathway and maintaining the abundance of gut microbiota

Dysfunction of the intestinal mucosal barrier of chicks caused by Salmonella pullorum is of great harm to the poultry industry. Probiotics are recognized for their beneficial health-promoting properties, promoting maintenance of bowel epithelial integrity and host immune system homeostasis. Our previous research showed that Lactobacillus casei protects jejunal mucosa from injury in chicks infected with S. pullorum. However, the specific mechanisms underlying its protective properties are still not fully understood. In the present study, we aimed to explore the mechanisms underlying the protective effects of L. casei on the intestinal mucosal barrier of chicks infected with S. pullorum through histological, immunological, and molecular biology methods. The results indicated that L. casei significantly reduced the diarrhea rate, increased the daily weight gain, and maintained normal levels of IgA, IgM, and IgG in the serum of chicks infected with S. pullorum. Furthermore, we found that L. casei markedly improved the immunity of gut mucosa by regulating cytokine and chemokine receptor balance, elevating the number of intraepithelial lymphocytes, and hence effectively restraining bowel inflammation. Strikingly, feeding of infected chicks with L. casei notably boosted interleukin-22 expression to activate the Wingless-Int pathway, moderated diamine oxidase and D-lactic acid levels, diminished the generation of myosin light chain kinase, and expanded tight junction protein levels (Zonulin-1 and Claudin-1), strengthening the function of the gut mucosal epithelium. In addition, experiments using 16S rDNA sequencing also demonstrated that L. casei immensely weakened the adhesion of S. pullorum, mainly manifesting as improved diversity of the intestinal microbiota in the V4 area of infected chicks. Taken together, these results show that the application of L. casei may be a good strategy to regulate the intestinal inflammatory response of chicks infected with S. pullorum, providing new perspectives in producing antibiotic substitutes in poultry farms.

Prevalence, Risk Factors, and Antibiogram of Nontyphoidal Salmonella from Beef in Ambo and Holeta Towns, Oromia Region, Ethiopia

Background

Salmonella has been recognized as a major cause of food-borne illness associated with the consumption of food of animal origin. The present cross-sectional study was conducted from December 2017 to May 2018 in Ambo and Holeta towns to assess the prevalence, risk factors, and antimicrobial susceptibility patterns of nontyphoidal Salmonella isolates from raw beef samples from abattoirs, butchers, and restaurants in Ambo and Holeta towns, Oromia region, Ethiopia.

Methods

A total of 354 beef samples were collected from abattoirs, butchers, and restaurants. Salmonella isolation and identification were carried out using standard bacteriological methods recommended by the International Organization for Standardization. Antimicrobial susceptibility testing was performed using the disk diffusion method. Besides, a structured questionnaire was used to collect sociodemographic data and potential risk factors for contamination of meat. Chi-square tests and logistic regression were used for data analyses.

Results

Of the total 354 meat samples examined, 20 (5.7%, 95% confidence interval (CI): 3.5–8.6) were positive for Salmonella. Two serotypes belonging to S. typhimurium (11 isolates) and I:4,5,12: i:- (9 isolates) were identified. The Salmonella detection rate in abattoirs, butchers, and restaurants was 4.2% (5/118), 8.5% (10/118), and 4.2% (5/118), respectively. The antimicrobial susceptibility test showed that 40%, 30%, and 20% of the Salmonella isolates were resistant to azithromycin, amoxicillin, and ceftriaxone, respectively. The odds of Salmonella isolation when meat handlers are illiterate were 7.8 times higher than those when they are educated to the level of secondary and above (P=0.032). Similarly, the likelihood of Salmonella isolation was 6.3 and 7.6 times higher among workers of butcher and restaurants, respectively, who had no training (P=0.003) and no knowledge (P=0.010) on food safety and hygiene.

Conclusions

The study showed widespread multidrug-resistant Salmonella isolates in the study areas. Therefore, raw meat consumption and indiscriminate use of antimicrobial drugs should be discouraged. Provision of food safety education for meat handlers and further surveillance of antimicrobial-resistant isolates are suggested.

Assessment of Hygienic Practices in Beef Cattle Slaughterhouses and Retail Shops in Bishoftu, Ethiopia: Implications for Public Health

Understanding the potential drivers of microbial meat contamination along the entire meat supply chain is needed to identify targets for interventions to reduce the number of meatborne bacterial outbreaks. We assessed the hygienic practices in cattle slaughterhouses (28 employees) and retail shops (127 employees) through face-to-face interviews and direct personal observations. At the slaughterhouses, stunning, de-hiding and evisceration in vertical position, carcass washing and separate storage of offal were the identified good practices. Lack of hot water baths, absence of a chilling room, infrequent hand washing, insufficiently trained staff and irregular medical check-up were practices that lead to unhygienic handling of carcasses. At the retail shops, cleaning equipment using soap and hot water (81%), storing unsold meat in refrigerators (92%), concrete floors and white painted walls and ceilings were good practices. Adjacently displaying offal and meat (39%), lack of a cold chain, wrapping meat with plastic bags and newspapers, using a plastic or wooden cutting board (57%), infrequent washing of equipment and floors, and inadequately trained employees were practices that could result in unhygienic handling of beef. Our study identified unhygienic practices both at the slaughterhouses and retail shops that can predispose the public to meatborne infections, which could be improved through training and implementation of quality control systems.

Prevalence, Antimicrobial Resistance, and Molecular Characterization of Salmonella in Cattle, Beef, and Diarrheic Patients in Bishoftu, Ethiopia

Within Ethiopia, there is a lack of information on the genetic relatedness of Salmonella from cattle, beef, and diarrheic patients and its potential transmission from cattle to humans through consumption of contaminated beef. The objective of this study was to assess the prevalence and determine the serotypes, genetic relatedness, and antimicrobial resistance of Salmonella in cattle in two local slaughterhouses, in beef at retail shops, and in diarrheic patients in the only hospital in Bishoftu, Ethiopia. Salmonella was detected in 2.5% (6/240) of cattle samples, in 8.7% (11/127) of beef samples, and in 2.3% (5/216) of the diarrheic patients. Four Salmonella serotypes: Salmonella Typhimurium, Salmonella Eastbourne, Salmonella Saintpaul, and Salmonella Cotham were identified. Salmonella Typhimurium and Salmonella Eastbourne were isolated from cattle and beef, whereas Salmonella Saintpaul and Salmonella Cotham were isolated only from diarrheic patients. Except for serotype Salmonella Saintpaul, all isolates were grouped into five pulsotypes, of which two pulsotypes contained isolates from cattle and beef. Isolates from humans represented unique pulsotypes. Among the 22 Salmonella isolates tested, 95.5% were resistant to at least 1 of the 14 antimicrobials tested. Three Salmonella isolates originating from cattle were multidrug resistant. One human isolate was susceptible to all antimicrobials tested. More specifically, resistance to ampicillin, sulfamethoxazole, tetracycline, tigecycline, and trimethoprim were observed. The most frequently observed resistance was to sulfamethoxazole (90.9%, 20/22) followed by trimethoprim (22.7%, 5/22). The study revealed considerable Salmonella contamination of beef at retail shops, antimicrobial resistance to commonly used antimicrobials, and shared genetically similar Salmonella serotypes between cattle and beef; the link with humans could not be established. Still, the findings of Salmonella in cattle and beef, the propensity of transfer of Salmonella from cattle to beef coupled with the common consumption of raw/undercooked beef are likely to pose public health risk in Ethiopia.

Review of the prevalence of foodborne pathogens in milk and dairy products in Ethiopia

Food safety is a significant barrier to social and economic development throughout the world, particularly in developing countries. Here, we reviewed the prevalence of major bacterial foodborne pathogens (Salmonella spp., Listeria monocytogenes, Escherichia coli O157:H7 and Campylobacter spp.) in the rapidly growing Ethiopian dairy supply-chain. We identified 15, 9, 5 and 0 studies that had reported the prevalence of Salmonella spp., L. monocytogenes, E. coli O157:H7, and Campylobacter spp. in dairy foods, respectively. The studies reviewed reported a median prevalence of Salmonella, L. monocytogenes, and E. coli O157:H7 of 6, 9 and 10%, respectively, in raw cow milk in Ethiopia, indicating a concerning occurrence of bacterial foodborne pathogens in raw milk. Implementation of good hygiene and production practices and assessment of interventions targeting the reduction of contamination in the dairy supply chain is needed to inform coordinated efforts focused on improvement of dairy food safety in Ethiopia.

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.

Review on Major Food-Borne Zoonotic Bacterial Pathogens

Food-borne microorganisms are major pathogens affecting food safety and cause human illness worldwide as a result of consumption of foodstuff, mainly animal products contaminated with vegetative pathogens or their toxins. Most of these microbes have zoonotic importance resulting in significant impact on both public health and economic sectors. Bacteria are the causative agents of two-thirds of human food-borne diseases worldwide with high burden in developing countries. Hence, the objectives of this review paper are to highlight the background of food-borne bacterial pathogens and to review common major food-borne zoonotic bacterial pathogens. Food animals are the major reservoirs of many food-borne zoonotic bacterial pathogens, and food products of animal origin are the main vehicles of transmission. Meat, dairy products, and eggs are the main ways by which people are exposed to zoonotic bacteria. S. aureus, Salmonella species, Campylobacter species, L. monocytogenes, and E. coli are the major zoonotic bacterial pathogens which are the causative agents of food-borne illness and death in the world associated with consumption of contaminated animal products. Production of toxins and structural virulent factors are responsible for the pathogenesis of these bacteria. These major zoonotic bacteria cause human infections which are characterized mainly by gastrointestinal symptoms including nausea, vomiting, diarrhea, abdominal cramps, and other agent-specific symptoms. Some bacteria may cause severe complications. Conventional (culturing), serological, and molecular techniques are important for detection of these common zoonotic bacteria and their toxins in food. Good hygiene, GMP, sanitation in operating procedures, and implementation of standardized HACCP and pasteurization procedures are effective methods for the control and prevention. Currently, the emergence of multidrug-resistant zoonotic bacteria associated with consumption of contaminated animal products is a great concern for the public health, and there should be coordinated surveillance and monitoring system for food-borne zoonotic bacterial pathogens particularly in developing countries including Ethiopia.

A cross-sectional study of enteric fever among febrile patients at Ambo hospital: prevalence, risk factors, comparison of Widal test and stool culture and antimicrobials susceptibility pattern of isolates

Background

Enteric fever is one of the common infectious diseases of humans. The objectives of this study were to:1) estimate the prevalence of enteric fever among febrile patients visiting Ambo hospital; 2) comparison of Widal test and stool culture;3) evaluation of the antimicrobial susceptibility of isolates; and 4) assess potential risk factors to acquire enteric fever infection.

Methods

Blood and stool samples were collected from 372 febrile patients with symptoms clinically similar to enteric fever. Widal test was used for testing sera while stool culturing and bacterial identification was done using WHO standard methods. Susceptibility testing was done using Kirby-Bauer disc diffusion method. Chi-Square test and Logistic Regression analysis were used to analyze the data.

Results

The apparent and true prevalence of enteric fever were 56.2% (95% confidence interval [CI]: 50.97–61.29%) and 57.52% (95% CI: 52.3–62.6%) respectively, while, the culture prevalence was 2.7% (95% CI: 1.30–4.89%). Isolation rates of S. Typhi and S. Paratyphi were 0.8% (95% CI: 0.17–2.34%) and 1.9% (95% CI: 0.76–3.84%) respectively. The isolates showed 100% resistance to amoxicillin, bacitracin, erythromycin, 80%resistance to cefotaxime and streptomycin and 20% for chloramphenicol. The sensitivity, specificity, positive and negative predictive values of Widal test was 80.0, 44.5, 3.8 and 98.8% respectively. Multivariable logistic regression analysis revealed that age (adjusted odds ratio [aOR] = 2.45; 95% CI: 1.38–4.37; P = 0.002), religion (aOR = 15.57, 95% CI: 3.01–80.64; P = 0.001), level of education (aOR = 2.60, 95% CI: 1.27–5.28; P = 0.009), source of water (aOR = 2.20, 95% CI: 1.21–3.98; P = 0.009), raw milk (aOR =2.19, 95% CI:1.16–4.16; P = 0.016) and raw meat consumption (aOR = 1.80, 95% CI: 1.07–3.01; P = 0.026) are the predictors of enteric fever seropositivity.

Conclusions

Patients were wrongly diagnosed and treated for enteric fever by Widal test. Therefore, rapid tests with better sensitivity and specificity are needed for the diagnosis of enteric fever. Provision of safe water and health education are vital to bring behavioral change towards raw food consumption.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-3917-3) contains supplementary material, which is available to authorized users.

Analysis of bacterial contamination and antibiotic residue of beef meat from city slaughterhouses in East Java Province, Indonesia

Aim:

This research aimed to analyze the presence of microbial contamination and antibiotic residue in beef meat from city slaughterhouses in East Java Province, Indonesia.

Materials and Methods:

A total of 40 samples from city slaughterhouses were used in this study. The tests for microbial contamination used several methods including total plate count (TPC), most probable number of Escherichia coli, detection of Staphylococcus aureus using Mannitol Salt Agar media, Salmonella spp. detection using Bismuth Sulfite Agar media and Triple Sugar Iron Agar media, and detection of the antibiotic residue by screening tests.

Results:

Most of the samples were contaminated with E. coli (32.5% positive samples) and S. aureus (20.0% positive samples). The mean values of TPC and S. aureus contamination were lower than the maximum limit of contamination, which were 41.58 CFU/g and 13.93 CFU/g, respectively, while the mean value of E. coli contamination was 27.03 CFU/g which was higher than the maximum limit. A low frequency of TPC (5% positive samples) and Salmonella spp. contamination (2.5% positive samples) was found in meat samples. Meat samples from two of the surveyed slaughterhouses were tested positive for antibiotic residue and six of the 40 samples (15%) were also tested positive for the antibiotic residue.

Conclusion:

It was concluded that most of the microbial contamination in beef meat from city slaughterhouses was below the maximum limit of contamination and only two slaughterhouses were found antibiotic residues in the meat samples.

Burden of intestinal pathogens and associated factors among asymptomatic food handlers in South Ethiopia: emphasis on salmonellosis

Objective

The study aims to assess the burden of intestinal parasites and Salmonellosis among asymptomatic food handlers at meal serving facilities in Sodo town. Antibiotic resistance was also common and increasing among Salmonella isolates with multidrug resistance as current concern.

Result

Community based cross-sectional study was carried out from 387 food handlers working in meal serving facilities. Food handlers, 159(41%) had one or more intestinal parasites. A. lumbricoides was the most prevalent parasite 30(7.8%), followed by Taenia species 26(6.7%) and Hook worm 23(5.9%). A total number of 35 Salmonella isolates were found of which Sero-group D was the most frequent, 17(48.5%) followed by Sero-group C, 12(34.3%), and B 6(17.1%). Ten (2.5%) isolates were Salmonella typhi. Raw meat eating, hand washing after toilet and after touching dirty materials showed significant association with intestinal pathogens. Salmonella isolates were highly resistant to ampicillin (85.7%), amoxicillin and tetracycline 74.3% each. Multidrug resistance prevalence of 81.8% was identified. Periodic screening of food handlers is important in order to prevent the transmission of intestinal parasites and Salmonellosis. Treatment needs to be based on accurate laboratory detection to mitigate the spread of drug resistant Salmonella strains.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3610-4) contains supplementary material, which is available to authorized users.

Characterization of Salmonella enterica from invasive bloodstream infections and water sources in rural Ghana

Background

Non-typhoidal Salmonella (NTS) cause the majority of bloodstream infections in Ghana, however the mode of transmission and source of invasive NTS in Africa are poorly understood. This study compares NTS from water sources and invasive bloodstream infections in rural Ghana.

Methods

Blood from hospitalised, febrile children and samples from drinking water sources were analysed for Salmonella spp. Strains were serotyped to trace possible epidemiological links between human and water-derived isolates.. Antibiotic susceptibility testing was performed,

Results

In 2720 blood culture samples, 165 (6%) NTS were isolated. S. Typhimurium (70%) was the most common serovar followed by S. Enteritidis (8%) and S. Dublin (8%). Multidrug resistance (MDR) was found in 95 (58%) NTS isolates, including five S. Enteritidis. One S. Typhimurium showed reduced fluroquinolone susceptibility. In 511 water samples, 19 (4%) tested positive for S. enterica with two isolates being resistant to ampicillin and one isolate being resistant to cotrimoxazole. Serovars from water samples were not encountered in any of the clinical specimens.

Conclusion

Water analyses demonstrated that common drinking water sources were contaminated with S. enterica posing a potential risk for transmission. However, a link between S. enterica from water sources and patients could not be established, questioning the ability of water-derived serovars to cause invasive bloodstream infections.

Salmonella serotypes and their antimicrobial susceptibility in apparently healthy dogs in Addis Ababa, Ethiopia

BACKGROUND

The close bond between pet animals and family members poses risk of infection with zoonotic bacterial pathogens such as Salmonella. No data is available on occurrence of Salmonella in dogs in Ethiopia. The aim of this study was therefore to determine the prevalence, serotype distribution and antimicrobial resistance of Salmonella from feces of apparently healthy dogs in Addis Ababa, Ethiopia.

RESULTS

Of the total 360 dogs examined, 42 (11.7%; 95% Confidence limit of 8.5%-15.4%) were positive for Salmonella. Fourteen serotypes were detected and the predominant ones were S. Bronx (n = 7; 16.7%), S. Newport (n = 6; 14.3%), followed by S. Typhimurium, S. Indiana, S. Kentucky, S. Saintpaul and S. Virchow (n = 4; 9.5%) each. Salmonella infection status was significantly associated with history of symptom of diarrhea during the past 60 days (OR = 3.78; CI = 1.76-8.13; p = 0). Highest resistance rates were found for oxytetracycline (59.5%), neomycin (50%), streptomycin (38.1%), cephalothin (33.3%), doxycycline (30.9%), ampicillin (30.9%) and amoxicillin + clavulanic acid (26.2%). Thirty eight (90.5%) of the isolates were resistant or intermediately resistant to at least one of the 16 antimicrobials tested. Resistance to two or more antimicrobials was detected in 30 (71.4%) of the isolates. Resistance to three or more antimicrobials was detected in 19 (45.2%) of the isolates.

CONCLUSION

This study demonstrated high carriage rate of Salmonella serotypes known for causing human salmonellosis and large proportion of them were resistant to antimicrobials used in public and veterinary medicine for management of various bacterial infections, suggesting the possible risk of infection of human population in close contact with these dogs by drug resistant pathogens. Therefore, it is vital to work on raising public awareness on zoonotic canine diseases prevention measures and good hygienic practices.

Isolation, Identification, and Antibiotic Susceptibility Testing of Salmonella from Slaughtered Bovines and Ovines in Addis Ababa Abattoir Enterprise, Ethiopia: A Cross-Sectional Study

Salmonellae are ubiquitous, found in animals, humans, and the environment, a condition which facilitates transmission and cross contamination. Salmonella enterica serotypes exert huge health and economic impacts due to their virulence or carriage of antibiotic resistance traits. To address this significant issues with regard to public health, availability of adequate information on the prevalence and antibiotic resistance patterns of Salmonella, and establishment of adequate measures to control contamination and infection are needed. A cross-sectional study was conducted to assess the level of Salmonella infection in slaughtered bovines and ovines at Addis Ababa abattoir. Samples were collected randomly and processed for identification and antimicrobial susceptibility testing of Salmonella spp. From 280 animals examined, 13 (4.64%) (8 bovines and 5 ovines) were positive, with most samples (12/13, 92%) comprising Salmonella Dublin. Very high level of resistance to some antibiotics used in human medicine was detected. Most isolates were susceptible to gentamycin and amikacin. Nine (69%) of all isolates were resistant to multiple antibiotics. Serotyping revealed 12 of 13 isolates to be of the Dublin serotype with 9,12:g,p:- antigenic formula. This study emphasizes the importance of improving the evisceration practice during slaughtering and restricting the use of antibiotics in farm animals.

Distribution of Salmonella Serovars and Antimicrobial Susceptibility from Poultry and Swine Farms in Central Vietnam

This study was conducted to estimate the prevalence of Salmonella spp. and their antimicrobial susceptibilities on poultry and swine farms, sampled in 2 regions in Central Vietnam. A total of 67 poultry farms and 46 swine farms were sampled in a period of 5 months (from September 2012 to January 2013). Salmonella spp. was prevalent in 46.3% and 71.7% of poultry and swine farms, respectively. Altogether, 99 non-typhoidal Salmonella were isolated and the most common serovars were Salmonella Weltevreden (19%), followed by Salmonella Typhimurium (12%) and Salmonella 4,[5],12:i:- (11%). Overall, 71 of 99 (72%) Salmonella isolates were resistant to at least one of the 14 antimicrobial agents tested. Both in poultry and swine farms, high levels of resistance were observed for ampicillin, chloramphenicol, ciprofloxacin, sulphamethoxazole and tetracycline. The presence of Salmonella isolates from poultry and swine farms which were resistant to different classes of antimicrobials suggests that alternative control measures to antimicrobials should be implemented. Moreover, an effective policy should be promoted to encourage a prudent use of these agents in animal farming in Vietnam.