Microbial quality and associated health risks of raw milk marketed in the Tanga region of Tanzania

Identification and antimicrobial susceptibility profiles of Staphylococcus species isolated from raw cow milk, and swabs in smallholder dairy farms in Meta district, Eastern Ethiopia

BACKGROUND

The safety of milk production in terms of foodborne infections is a worldwide issue, particularly in developing countries where production is often unhygienic. A cross-sectional study was conducted from December 2018 to August 2019 in the Meta District of Eastern Hararghe Zone, Oromia Regional State, Ethiopia. We aim to assess milk hygiene practices among smallholder dairy farmers, estimate the prevalence of Staphylococcus aureus in raw cow milk and swabs, assess associated risk factors, and the antimicrobial susceptibility test of S. aureus isolates. Face-to-face interviews with 30 respondents randomly selected from smallholder dairy farmers were used to assess the potential risk factors for S. aureus contaminations in milk. A total of 177 samples were examined using standard microbiological testing. The disc diffusion technique was also employed to assess the antibiotic susceptibility of the isolates. The data was analyzed using STATA® version 14.0 statistical software.

RESULTS

According to the milk hygiene assessment, 80% of respondents did not wash cow udder before milking, did not use detergent to clean milk containers, and did not keep milk refrigerated before consumption or sale, while 63.3% of milk consumers ingested raw milk. They had never heard of staphylococci foodborne disease. Likewise, the overall prevalence of S. aureus was 12.42% (95%CI: 8.32-18.98). The prevalence of S. aureus in udder milk, equipment swabs, and milkers' hands was 18.8%, 26.7%, and 30%, respectively. The prevalence of S. aureus in milk is significantly associated with age, and mastitis history (p < 0.05). Moreover, old and mastitis positive animals were eight (OR: 8.40; 95%CI: 1.68-41.89) and four (OR: 4.33; 95%CI: 1.37-13.66) times more likely to be infected by S. aureus than adult, and mastitis negative animal. The isolates were resistant to penicillin G (97.4%) and tetracycline (69.2%) whereas susceptible to kanamycin, streptomycin, vancomycin, and cefotaxime, at 84.6%, 71.8%, 64%, and 58.8%, respectively.

CONCLUSION

This study revealed the presence of antimicrobial-resistant patterns of S. aureus on commonly used antibiotics, as well as inadequate milk handling practices in the study area. Thus, awareness should be created on proper milk handling and hygiene as well as appropriate uses of antibiotics should be encouraged.

Graphene-based biosensors in milk analysis: A review of recent developments

Cow's milk, an excellent source of fat, protein, amino acids, vitamins and minerals, is currently one of the most consumed products worldwide. Contaminations originating from diverse sources, such as biological, chemical, and physical, cause dairy product quality problems and thus dairy-related disorders, raising public health issues. For this reason, legal authorities have deemed it necessary to classify certain contaminations in commercial milk and keep them within particular limitations; therefore, it is urgent to develop next-generation detection systems that can accurately identify just the contaminants of concern to human health. This review presents a detailed investigation of biosensors based on graphene and its derivatives, which offer superior sensitivity and selectivity, by classifying the contaminants under the headings biological, chemical, and physical, in cow's milk according to their sources. We reviewed the current status of graphene-based biosensor (GBs) technology for milk or dairy analysis, highlighting its strengths and weaknesses with the help of comparative studies, tables, and charts, and we put forward a novel perspective to handle future challenges.

Brucellae as resilient intracellular pathogens: epidemiology, host-pathogen interaction, recent genomics and proteomics approaches, and future perspectives

Brucellosis is considered one of the most hazardous zoonotic diseases all over the world. It causes formidable economic losses in developed and developing countries. Despite the significant attempts to get rid of Brucella pathogens in many parts of the world, the disease continues to spread widely. Recently, many attempts proved to be effective for the prevention and control of highly contagious bovine brucellosis, which could be followed by others to achieve a prosperous future without rampant Brucella pathogens. In this study, the updated view for worldwide Brucella distribution, possible predisposing factors for emerging Brucella pathogens, immune response and different types of Brucella vaccines, genomics and proteomics approaches incorporated recently in the field of brucellosis, and future perspectives for prevention and control of bovine brucellosis have been discussed comprehensively. So, the current study will be used as a guide for researchers in planning their future work, which will pave the way for a new world without these highly contagious pathogens that have been infecting and threatening the health of humans and terrestrial animals.

Assessing milk products quality, safety, and influencing factors along the dairy value chain in eastern Democratic Republic of the Congo

Dairying is one of the new promising economic sectors in eastern Democratic Republic of Congo (DRC), but still not explored enough to ensure consumers' safety. This study aimed to assess the health risks and nutritional profile of milk products along the value chain in South-Kivu and Tanganyika provinces. A total of 288 milk actors, including 160 producers, 35 collectors and 93 vendors, were concerned for interview and milk samples collection. A total of 302 milk samples (159 raw, 44 pasteurized, 76 fermented and 19 white cheese so-called “Mashanza”) were collected for physicochemical [pH, fat, non-fat dry matter (NFDM), lactose, protein, freezing point, density] and microbiological (total Aerobic Mesophilic Flora, Escherichia coli, Total Coliforms, Fecal Coliforms, Salmonella and Staphylococci) analyses. Results revealed that the physicochemical characteristics of the milk mostly varied according to the type of milk and the regions. The pasteurized milk from Tanganyika presented the best physicochemical parameters [crude protein (CP) = 4.36%, Fat = 4.06%, NFDM = 12%, lactose = 5.4%, density = 1.02 and pH = 6.59] compared to other types of milk. For microbiology, no E. coli was recorded but Salmonella and Staphylococci were found in all the milk types with the values not exceeding 3 × 104 CFU ml−1 and 3 × 103 CFU ml−1, respectively. This implies a long-term consumers' health issue if appropriate measures are not taken by milk actors along the value chain. The microbiological quality was influenced by the ecologies of production axis (representing the production zones) and by handling methods and infrastructures used by the actors involved along the value chain. Factors related to animal husbandry, milking method, milk processing and packaging had no significant effect on the physicochemical parameters under study. These results indicated that health risks for milk consumers are accrued by production practices and handling by milk actors due to shortage of required skills and appropriate equipment along the milk value chain. Observance of hazard analysis critical control point (HACCP) measures is carefully required along the milk value chain nodes to improve the quality of milk produced and sold and thus reduce the risks among consumers in South-Kivu and Tanganyika provinces.

Occurrence and antimicrobial resistance pattern of E. coli O157:H7 isolated from foods of Bovine origin in Dessie and Kombolcha towns, Ethiopia

E. coli are frequently isolated food-borne pathogens from meat, milk, and their products. Moreover, there has been a significant rise in the antimicrobial resistance patterns of E. coli O157:H7 to commonly used antibiotics. A cross-sectional study was conducted from October 2019 to July 2021 to estimate prevalence and identify associated factors of E. coli and E. coli O157:H7 and to determine antibiotic resistance pattern of E. coli O157:H7 from foods of bovine origin in Dessie and Kombolcha towns. A total of 384 samples were collected. Systematic and simple random sampling techniques were employed for sampling carcasses and milking cows, respectively. E. coli and E. coli O157:H7 were detected according to recommended bacteriological protocols. E. coli O157:H7 strains were evaluated for in vitro antimicrobial susceptibility using agar disk diffusion method. Both descriptive and inferential statistical techniques were applied to analyze the data. Overall prevalence rates of E. coli and E. coli O157:H7 were 54.7% and 6.5%, respectively. Highest prevalence rates of E. coli (79.6%) and E. coli O157:H7 (16.7%) were obtained from carcass swabs and milk tank samples, respectively. Unlike E. coli O157:H7, a statistically significant difference in the E. coli prevalence (P<0.05) was observed among the different sample types. Multidrug resistance was observed among all isolates of E. coli O157:H7. All E. coli O157:H7 isolates (100.0%) were susceptible to Ampicillin, Sulfamethoxazole-trimethoprim, and Norfloxacin. On the contrary, all of the isolates (100%) were resistant to Penicillin G, Vancomycin, and Oxacillin. The current study indicated that different foods of bovine origin in the study area were unsafe for human consumption. Hence, good hygienic production methods should be employed to ensure the safety of foods of bovine origin.

Microbiological Quality of Raw Donkey Milk from Serbia and Its Antibacterial Properties at Pre-Cooling Temperature

The aim of this study was to examine the microbiological quality of raw donkey milk of an indigenous Serbian breed as well as the changes in the microbial populations during storage at 4 °C. In addition, antibacterial activity of donkey milk against E. coli, L. monocytogenes and S. aureus at 15 °C as well as the content of the two main antibacterial proteins lysozyme and lactoferrin were investigated. Microbiological examination of 137 individual milk samples collected over a period of 21 months showed good microbiological quality since foodborne pathogens such as Salmonella spp. and L. monocytogenes were not detected in any of the analyzed samples, while the number of E. coli, Enterobacteriaceae, total coliform bacteria, sulfite-reducing Clostridia and aerobic sporogenic bacteria was below the limit of quantification (<1 cfu mL^-1). During the six-days storage at 4 °C, total bacterial counts and the counts of lactic acid bacteria remained at the initial level while pathogenic bacteria were not detected. The strongest antibacterial activity of the tested milk was observed against E. coli, while S. aureus was the least sensitive to milk antibacterial compounds. Although further research is needed to fully elucidate the antibacterial mechanism and synergistic activity of different compounds in donkey milk, the high content lysozyme (2.63 ± 0.03 g L^-1) and lactoferrin (15.48 mg L^-1) observed in tested milk could contribute to its strong antibacterial activity and extension of the storage period during which it can be safely consumed.

Epidemiology and Antimicrobial Susceptibility Pattern of E. coli O157:H7 Along Dairy Milk Supply Chain in Central Ethiopia

Background

Enterohemorrhagic Escherichia coli (O157:H7) is the primary cause of bloody diarrhea or hemorrhagic colitis. The study was carried out with to determine the epidemiology and antimicrobial resistance pattern of E. coli O157:H7 along the dairy supply chains in Akaki Kaliti sub-city of Addis Ababa, Bishoftu and Sululta towns of central Ethiopia.

Methods

A cross-sectional study design with random sampling methods was employed. Thus, a total of 450 raw cow milk (294), milker hand swab (65) and water (91) samples were collected from dairy farms, milk collection centers and Cafeterias and processed according to the standards to isolate and identify E. coli O157:H7. The samples were initially enriched in buffered peptone water, then plated onto Sorbitol MacConkey agar. Consequently, the suspected non-sorbitol fermenting colonies were confirmed as E. coli biochemically and serological test using latex agglutination tests.

Results

Out of the total 450 samples examined, 6.0% were found to be contaminated by E. coli O157:H7. Accordingly, 9.89% of water, 9.23% of milker hand swab and 4.08% of raw milk samples were contaminated by the pathogen. Furthermore, the prevalence of E. coli O157:H7 was 7.79%, 6.21% and 3.97% in Akaki kaliti sub-city, Sululta and Bishoftu towns, respectively. The result of Fisher exact analysis revealed a significant difference observed (p < 0.05) between the occurrence of the pathogen and the source of sample, sources of water used, sampled material and type of containers. The study also revealed that varying level of resistance of E. coli O157:H7 isolates against nine antimicrobial discs tested and 100% (n = 27) of the isolates showed multidrug-resistance comprising from two up to seven antimicrobial drugs.

Conclusion

In conclusion, this study has indicated the occurrence of E. coli O157:H7 and its multiple drug-resistant profiles in milk samples along the dairy supply chains and its risk to public health and food safety. Therefore, proper hygienic practices from dairy farms to fork and rational drug usage are recommended.

Assessment of Milk Quality and Food Safety Challenges in the Complex Nairobi Dairy Value Chain

Food networks present varying food safety concerns because of the complexity of interactions, production, and handling practices. We investigated total bacteria counts (TBCs) and total coliform counts (TCCs) in various nodes of a Nairobi dairy value chain and identified practices that influence food safety. A value chain analysis framework facilitated qualitative data collection through 23 key informant interviews and 20 focus group discussions. Content thematic analysis identified food safety challenges. Cow milk products (N = 290) were collected from farms (N = 63), collection centers (N = 5), shops/kiosks (N = 37), milk bars (N = 17), roadside vendors (N = 14), restaurants (N = 3), milk vending machines (N = 2), mobile traders (N = 2) and a supermarket (N = 1). Mean values of colony-forming units for TBC and TCC were referenced to East African Standards (EAS). Logistic regression analysis assessed differences in milk acceptability based on EAS. The raw milk from farms and collection centers was relatively within acceptable EAS limits in terms of TBC (3.5 × 10⁵ and 1.4 × 10⁶ respectively) but TCC in the milk from farms was 3 times higher than EAS limits (1.5 × 10⁵). Compared to farms, the odds ratio of milk acceptability based on TBC was lower on milk bars (0.02), restaurants (0.02), roadside vendors (0.03), shops/kiosks (0.07), and supermarkets (0.17). For TCC, the odds that milk samples from collection centers, milk bars, restaurants, roadside vendors, and shops/kiosks were acceptable was less than the odds of samples collected from farms (0.18, 0.03, 0.06, 0.02, and 0.12, respectively). Comparison of raw milk across the nodes showed that the odds of milk samples from restaurants, roadside vendors, and shops/kiosks being acceptable were less than the odds of samples collected the farm for TBC (0.03, 0.04, and 0.04, respectively). For TCC, the odds of raw milk from collection centers, restaurants, roadside vendors, milk bars, and shops/kiosks being acceptable were lower than the odds of acceptability for the farm samples (0.18, 0.12, 0.02, 0.04, and 0.05, respectively). Practices with possible influence on milk bacterial quality included muddy cowsheds, unconventional animal feed sources, re-use of spoilt raw milk, milk adulteration, acceptance of low-quality milk for processing, and lack of cold chain. Therefore, milk contamination occurs at various points, and the designing of interventions should focus on every node.

Epidemiological Investigation of Bovine Brucellosis in Indigenous Cattle Herds in Kasulu District of Tanzania

Background: Livestock-wildlife interfaces create unique hotspots of many infectious diseases including brucellosis. Methods: A combination of epidemiological field studies utilizing Participatory Epidemiology tools and cross-sectional studies investigating Abortion Associated Syndrome (AAS) was conducted in livestock wildlife interface areas in Kasulu district, Tanzania from 23 to 28 July 2019. A total of 285 cattle from 27 herds were examined and sampled. Individual animal and herd-level data were collected using a structured questionnaire. Serum samples were screened for anti-Brucella antibodies using the Rose Bengal Plate Test (RBPT). Results: Ranking and proportional piling showed cattle to be the most important animal species kept but also significantly contribute to the livelihood of the livestock keepers. Matrix scoring results showed weak to moderate agreement between informant groups perception on the AAS and risk factors. The overall seroprevalence of anti-Brucella antibodies in individual animal was 30.8% (95% Confidence intervals (CI) = 25.5 - 36.2) and the corresponding herd prevalence was 77.7% (95% CI = 59.2 - 89.4). Fifty-one (37.0%) out of the 138 cows that had history of abortion over the previous 2 years (2018-2019) prior to the study was seropositive on RBPT. Univariate logistic regression analysis showed sex and age of the animals as a potential predictor for individual animal seroprevalence. Conclusions: The results showed that farmer knowledge and perception about diseases including AAS to be moderate and further confirm brucellosis to be prevalent and widely distributed locally. Heightened routine surveillance, further studies, and institution of preventive and control measures particularly among young female stock should be implemented. Creating disease awareness especially amongst livestock keepers and general public who are at high risk of contracting brucellosis is desirable.

Brucellosis: Prevalence with reference to East African community countries - A rapid review

Brucellosis is a zoonotic disease which is endemic to certain regions of the world including Sub-Saharan Africa. The aim of this article is to provide a recent and rapid review on brucellosis prevalence in East African Community (EAC) countries. Literature was obtained using Google Scholar search engine and screened for relevancy and fulfilment of criteria to 1, 17, 4, 4, 30 and 29 articles retained for brucellosis prevalence in Burundi, Kenya, Rwanda, South Sudan, Tanzania and Uganda. Recent literature (published in the last decade 2010 to 2019) was considered for prevalence results in this review. In EAC, livestock had an animal-level prevalence of 0.2% to 43.8%, 0.0% to 20.0% and 0.0% to 13.8% for cattle, goats and sheep respectively. In humans, the prevalence varied mostly between 0.0% and 35.8%. In conclusion, brucellosis is quite prevalent in the region. The reported prevalence calls for plans or more efforts from individual member countries and from EAC, as a region, to control brucellosis.

Human brucellosis epidemiology in the pastoral area of Hulun Buir city, Inner Mongolia autonomous region, China, between 2003 and 2018

Human brucellosis represents a serious public health concern in Hulun Buir and requires a comprehensive epidemiologic analysis to define adapted control measures. The present study describes the case numbers, constituent ratios and incidence rate of human brucellosis. Conventional biotyping, that is abortus, melitensis, ovis and suis (AMOS)-PCR and multi-locus variable-number tandem repeat analysis (MLVA) were used to characterize the Brucella strains. Between 2003 and 2018, a total of 23,897 human brucellosis cases were reported, with an incidence rate of 56.03/100,000, which is 20 times higher than the country's average incidence. This incidence rate increased year after year, culminating in 2005 and decreased between 2011 and 2018. Because Hulun Buir relies on a nomadic livestock rearing system, brucellosis spreads easily among different animal species and humans. In Xin Barag Left Banner and Xin Barag Right Banner, the incidence rates were, respectively, 226.54/100,000 and 199.10/100,000, exceeding those observed in other areas. Most of the cases occurred in the 25- to 45-year-old group, accounting for 65.74% of the cases (15,709/23,897), and among farmers, accounting for 66.71% (15,942/23,897). The male to female incidence ratio was 2.67:1. The higher incidence in younger people and the large gender ratio reflected the unique traditional production and lifestyle of nomads. Most reported cases were observed from April to June, indicating that more than 40% of the cases were related to the delivery of domestic livestock. The biotyping showed that the 44 isolated strains were all B. melitensis, including 12 Brucella melitensis biovar (bv) 1 and 32 B. melitensis bv. 3. The strains displayed a genetic similarity of 80%-100%. Our hypothesis is that human brucellosis outbreak in this region may be originating from a limited source of infection, so further investigation is necessary. The epidemic situation of human brucellosis in Hulun Buir is extremely serious, strengthened surveillance and control in animals' brucellosis should be priority.

A review of microbes and chemical contaminants in dairy products in sub-Saharan Africa

Animal milk types in sub-Saharan Africa (SSA) are processed into varieties of products using different traditional methods and are widely consumed by households to support nutritional intake and diet. Dairy products contain several microorganisms, their metabolites, and other chemical compounds, some with health benefits and many others considered as potential health hazards. Consumption of contaminated milk products could have serious health implications for consumers. To access the safety of milk products across SSA, studies in the region investigating the occurrences of pathogens as well as chemical compounds such as heat stable toxins and veterinary drug residues in animal milk and its products were reviewed. This is done with a holistic view in light of the emerging exposome paradigm for improving food safety and consumer health in the region. Herein, we showed that several published studies in SSA applied conventional and/or less sensitive methods in detecting microbial species and chemical contaminants. This has serious implications in food safety because the correct identity of a microbial species and accurate screening for chemical contaminants is crucial for predicting the potential human health effects that undermine the benefits from consumption of these foods. Furthermore, we highlighted gaps in determining the extent of viral and parasitic contamination of milk products across SSA as well as investigating multiple classes of chemical contaminants. Consequently, robust studies should be conducted in this regard. Also, efforts such as development cooperation projects should be initiated by all stakeholders including scientists, regulatory agencies, and policy makers to improve the dairy product chain in SSA in view of safeguarding consumer health.

Meat Safety in Tanzania's Value Chain: Experiences, Explanations and Expectations in Butcheries and Eateries

Urbanisation is associated with changes in consumption patterns and food production processes. These patterns and processes can increase or decrease the risks of outbreaks of foodborne diseases and are generally accompanied by changes in food safety policies and regulations about food handling. This affects consumers, as well as people economically engaged in the food value chain. This study looks at Tanzania's red meat value chain-which in its totality involves about one third of the population-and focuses on the knowledge, attitudes and reported practices of operators of butcheries and eateries with regards to meat safety in an urban and in a rural environment. We interviewed 64 operators about their experiences with foodborne diseases and their explanations and expectations around meat safety, with a particular emphasis on how they understood their own actions regarding food safety risks vis-à-vis regulations. We found operators of eateries emphasising their own agency in keeping meat safe, whereas operators of butcheries-whose products are more closely inspected-relied more on official inspections. Looking towards meat safety in the future, interviewees in rural areas were, relative to their urban counterparts, more optimistic, which we attribute to rural operators' shorter and relatively unmediated value chains.

Pastoral community practices, microbial quality and associated health risks of raw milk in the milk value chain of Nakasongola District, Uganda

The informal milk value chain in Uganda controls most of the raw marketed milk, albeit of poor quality. A study was conducted to assess the milk handling practices, the bacterial quality and the associated health concerns of raw milk along the informal milk value in Nakasongola District. The cross-sectional study used both qualitative and quantitative methods to obtain information from key players. The qualitative data was categorized and presented into emerging themes. Bacterial contamination of 200 milk samples was determined by morphological and biochemical tests. The antibiotic susceptibility test was done by the disc diffusion method.

Hand milking was carried out mainly by men (92.5%), and most never or rarely practised hand washing (67.5%) during milking. Milk was mainly delivered to mobile milk-collecting centres located under tree shades (50%). The quality of raw milk was affected by poor hygienic, handling and transportation practices. Most participants (75%) were aware of the dangers of drinking raw milk and the requirements to transport milk in metallic cans. Viable bacterial counts above the recommended limit were recorded in 76 samples (38%) that included Staphylococcus aureus (46%), coagulase-negative Staphylococcus (29%), Escherichia coli (12%), Streptococcus agalactiae (8%) and Salmonella spp. (5%). The overall antibiotic resistance was 45% (34/76), which included resistant isolates of S. aureus (17/34), coagulase-negative Staphylococcus (11/22), S. agalactiae (3/6), Salmonella spp. (2/4) and E. coli (2/9).

The raw milk contaminated with antibiotic drug-resistant bacterial pathogens is of public health concern. Thus, measures to improve the quality of milk need to be designed for the pastoral community in Nakasongola district.

Comparisons of brucellosis between human and veterinary medicine

Brucellosis is the world's most widespread zoonosis, but also ranks as one of the seven most neglected diseases, according to the World Health Organization. Additionally, it is recognized as the world's most common laboratory-acquired infection. There are a reported 500,000 incident cases of human brucellosis per year. However, true incidence is estimated to be 5,000,000 to 12,500,000 cases annually. Once diagnosed, focus is directed at treating individual patients with antibiotic regimes, yet overall neglecting the animal reservoir of disease. Countries with the highest incidence of human brucellosis are Syria (1,603.4 cases per 1,000,000 individuals), Mongolia (391.0), and Tajikistan (211.9). Surveillance on animal populations is lacking in many developed and developing countries. According to the World Animal Health Information Database, Mexico had the largest number of reported outbreaks, 5,514 in 2014. Mexico is followed by China (2,138), Greece (1,268), and Brazil (1,142). The majority of these outbreaks is Brucella abortus, the etiologic agent of bovine brucellosis. Brucellosis is an ancient disease that still plagues the world. There are still knowledge gaps and a need for better diagnostics and vaccines to make inroads towards control and eradication.

Antimicrobial Resistance Profile of E. coli Isolated from Raw Cow Milk and Fresh Fruit Juice in Mekelle, Tigray, Ethiopia

Aim

Foodborne illnesses represent a public health problem in developed and developing countries. They cause great suffering and are transmitted directly or indirectly between animals and humans and circulate in the global environment. E. coli are among them, causing a major public health problem. The aim of this study was therefore to study the antimicrobial resistance profile of E. coli from raw cow milk and fruit juice.

Materials and Methods

A cross-sectional study was conducted from October 2016 to June 2017 on 258 samples collected from milk shops (n = 86), dairy farms (n = 86), and fruit juice (n = 86) in different subcities of Mekelle. Bacteriological procedures were used for isolation of E. coli in the collected samples and for identification of the antimicrobial resistance profile.

Result

The overall mean viable bacterial count and standard deviation of samples from milk shop, fruit juice, and dairy milk were found to be 8.86 ± 10⁷, 7.2 ± 10⁷, and 8.65 ± 10⁷ CFU/ml and 33.87 ± 10⁶, 6.68 ± 10⁶, and 22.0 ± 10⁶, respectively. Of the samples tested, 39 from milk shops (45.35%), 20 from fruit juice (23.26%), and 24 from dairy farms (27.91%) were found to be positive for E. coli. The isolated E. coli were highly resistant to ampicillin (70%), sulfamethoxazole-trimethoprim (60%), clindamycin (80%), erythromycin (60%), chloramphenicol (50%), and kanamycin (50%) and were found to be susceptible to some antibiotics like gentamicin (100%), norfloxacin (100%), tetracycline (60%), polymyxin B (90%), and ciprofloxacin (90%).

Conclusion

The current study supports the finding that raw milk and fruit juice can be regarded as critical source of pathogenic E. coli. This supports the need for strict monitoring and the implementation of effective hygienic and biosecurity measures in the whole food chain of these products as well as a prudent use of antimicrobials.

Consumer profile and problems associated with uninspected raw milk consumption in western Paraná

ABSTRACT: The objectives of this study were to analyze consumer profile; to identify the main reasons for raw milk consumption; and to analyze in laboratory samples of uninspected raw milk from five towns in the western region of the state of Paraná, Brazil. The types of milk most frequently consumed were: 42.3% ultra-high temperature (UHT), 38.3% pasteurized milk, 17.6% uninspected raw milk, and 1.7% powered milk. The frequencies of households that preferred uninspected raw milk were, according to the town, 32.7% in Iporã, 29.2% in Marechal Cândido Rondon, 18.9% in Assis Chateaubriand, 17.6% in Palotina, and 10% in Toledo. Flavor was the main reason for uninspected raw milk consumption, and the purchase of this product was more frequent in households whose income was between one to four minimum wages. It was observed that the sales of uninspected milk are more financially advantageous to the producer than sales of inspected milk. All samples analyzed showed lack of compliance with at least one parameter, 60.9% for mesophilic counts, 56.6% for non-fat dry matter, 52.1% for freezing point, 43.5% for acidity, 23.9% for density, 23.9% for the casein macropeptide, 17.4% for fat content, 8.7% were reactors in the milk ring test, and 2.2% were reactors in microbial growth inhibitor test. Fraud by addition of water was observed in 20% of the samples. Uninspected raw milk analyzed in this study involved a low-quality product that is a financial hazard as it may be adulterated, and that poses risk to consumer health.

Perceptions of Factors Affecting Milk Quality and Safety among Large- and Small-Scale Dairy Farmers in Zimbabwe

The study investigated the perceptions of milk producers on milk quality and safety. Randomly selected large-scale farmers (n=158) and small-scale farmers (n=186) were surveyed using semistructured questionnaires. An ordinal logistic regression was used to estimate the probability of farmers considering milk quality and safety important. Large-scale farmers were 3 times more likely to consider that breed affects milk quality compared to their small-scale counterparts. Farmers aged over 30 years were 3 times more likely to indicate that hygiene affected milk quality. The likelihood of milk transportation affecting its quality was 4 times higher in small-scale farmers compared to large-scale producers. Postmilking contamination of milk was perceived to occur during transportation by small-scale farmers, whilst commercial farmers ranked storage as the important source of contamination after milking. Udder diseases were ranked first by large-scale farmers while small-scale farmers ranked milking environment as the major cause of milk spoilage. The likelihood of milk safety being important was two times higher in large farms compared to small-scale farms. Intervention programmes on milk safety should mainly target small-scale dairy farmers since they are less concerned about milk quality and safety.

Prevalence of antibodies to Brucella species in commercial raw bovine milk in Southwestern Uganda

Objectives

The purpose and objective of this research was to explore the prevalence of antibodies against Brucella species in raw milk samples collected in Southwestern Uganda, one of the biggest milk producing regions in the Country. We hypothesized that there is a high level of antibodies in milk samples from this region. This builds more evidence to other studies in the region on the level contamination of raw milk.

Results

A total of 185 raw milk samples, collected from dairy farms and factories in southwestern region, were tested for antibodies to Brucella spp. using the milk ring test (MRT) and indirect Enzyme-Linked Immunosorbent Assay (i-ELISA).We found a prevalence of 26.5% (49/185) by the two methods. This is related to previous reports in the region and adds more evidence on the need for further investigations to confirm the source of these antibodies and their relationship with disease in milk producing animals.

Contamination Levels and Identification of Bacteria in Milk Sampled from Three Regions of Tanzania: Evidence from Literature and Laboratory Analyses

Milk in Tanzania has been reported to be contaminated with large number of bacteria. This is because (1) milk is obtained from animals with unknown health status, (2) good milking and handling practices are to a large extent not observed, and (3) marketing and distribution are done in informal channels. These factors are potential causes of milk-borne diseases and milk quality loss. The aim of this study was to assess nutritional risks in milk as reported in literature over a period of 20 years and through analyses of samples collected during the present study. The issues highlighted in literature were high bacteria and coliform counts exceeding standard levels in East Africa, prevalence of bacteria and drug residues in milk, and adulteration. Based on performed analyses, total bacterial count 1.0 × 10⁷ colony forming units per millilitre (cfu/ml) and total coliform count 1.1 × 10⁷ cfu/ml, also greater than recommended levels, were found. Ten bacteria types were isolated from milk samples (five, Pseudomonas aeruginosa, Listeria monocytogenes, Listeria innocua, Listeria ivanovii, and Klebsiella spp. are reported in Tanzanian for the first time). Two drugs tetracycline and sulphur were detected. Therefore, it is worth noting that integrated research is needed to evaluate the situation and address these challenges.

A review on detection methods used for foodborne pathogens

Foodborne pathogens have been a cause of a large number of diseases worldwide and more so in developing countries. This has a major economic impact. It is important to contain them, and to do so, early detection is very crucial. Detection and diagnostics relied on culture-based methods to begin with and have developed in the recent past parallel to the developments towards immunological methods such as enzyme-linked immunosorbent assays (ELISA) and molecular biology-based methods such as polymerase chain reaction (PCR). The aim has always been to find a rapid, sensitive, specific and cost-effective method. Ranging from culturing of microbes to the futuristic biosensor technology, the methods have had this common goal. This review summarizes the recent trends and brings together methods that have been developed over the years.

The milk delivery chain and presence of Brucella spp. antibodies in bulk milk in Uganda

This study examined the influence of informal milk delivery chains on the risk of human exposure to Brucella spp. through milk consumption in two regions of Uganda (Gulu and Soroti Districts). The work involved describing milk delivery chains, investigating brucellosis awareness amongst milk deliverers and determining the presence of Brucella spp. antibodies in cattle milk on delivery to primary collection points (boiling points and dairies). Milk samples (n = 331) were collected from deliverers at primary collection points and from street vendors at point of sale and analysed using indirect enzyme-linked immunosorbent assay (I-ELISA). A written questionnaire was used to collect data from deliverers (n = 279) on their milk delivery chains and their brucellosis awareness. The most common delivery points in Gulu District were small dairies and in Soroti District boiling points. The presence of Brucella spp. antibodies in milk samples was higher in Soroti (40 %) than in Gulu (11 %) (P < 0.0001). There are possible public health risk consequences of this finding as 42 % of deliverers in Soroti District reported drinking raw milk, compared with 15 % in Gulu District (P < 0.0001). Awareness of brucellosis was low, with 70 % of all milk deliverers reporting not having heard of the disease or the bacterium. Application of quality controls for milk (colour and odour) along the delivery chain varied depending upon supply and demand. This study provides evidence of the diversity of informal milk markets in low-income countries and of the potential public health risks of consuming unpasteurised milk. These results can be useful to those planning interventions to reduce brucellosis.

Microbiological quality and safety assessment of the Rwandan milk and dairy chain

Milk is a valuable and nutritious food product that can partially fulfill the rising food demand of the growing African population. The microbiological status of milk and derived products was assessed throughout the milk and dairy chain in Rwanda by enumeration of the total mesophilic count, coliforms, and Staphylococcus aureus and detection of Salmonella and Listeria monocytogenes. The quality of raw milk was satisfactory for the majority of samples, but 5.2% contained Salmonella. At the processing level, the total mesophilic count and coliform numbers indicated ineffective heat treatment during pasteurization or postpasteurization contamination. Increasing bacterial counts were observed along the retail chain and could be attributed to insufficient temperature control during storage. Milk and dairy products sold in milk shops were of poor and variable microbiological quality in comparison with the pasteurized milk sold in supermarkets. In particular, the microbiological load and pathogen prevalence in cheese were unacceptably high.

Identification and effect decomposition of risk factors for Brucella contamination of raw whole milk in china

BACKGROUND

Lack of clear risk factor identification is the main reason for the persistence of brucellosis infection in the Chinese population, and there has been little assessment of the factors contributing to Brucella contamination of raw whole milk. The purpose of this study was to identify risk factors affecting Brucella contamination of raw milk, and to evaluate effective measures for disease reduction in order to determine preventive strategies.

METHODS AND FINDINGS

A nationwide survey was conducted and samples were obtained from 5211 cows corresponding to 25 sampling locations throughout 15 provinces in China. The prevalence of Brucella in the raw milk samples averaged 1.07% over the 15 Chinese provinces, while the prevalence of positive areas within these regions ranged from 0.23-3.84% among the nine provinces with positive samples. The survey examined factors that supposedly influence Brucella contamination of raw whole milk, such as management style, herd size, abortion rate, hygiene and disease control practices. A binary logistic regression analysis was carried out to determine the association between risk factors for Brucella and contamination of milk samples. Furthermore, a relative effect decomposition study was conducted to determine effective strategies for reducing the risk of Brucella contamination of raw whole milk. Our data indicate that disease prevention and control measures, abortion rate, and animal polyculture are the most important risk factors. Meanwhile, culling after quarantine was identified as an effective protective measure in the current Chinese dairy situation.

CONCLUSIONS

These results indicate that, although there is a low risk of contamination of milk with Brucella nationwide in China, there are individual regions where contamination is a significant problem. Controlling three factors-culling after quarantine, maintaining a low abortion rate, and avoiding mixing groups of cattle and small ruminants-could effectively reduce the risk of Brucella contamination of raw whole milk.