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Background: In Ethiopia, milk production and handling practices often lack proper hygiene measures, leading to the potential contamination of milk and milk products with Staphylococcus aureus (S. aureus), including methicillin-resistant strains, posing significant public health concerns. This study aimed to investigate the occurrence, antimicrobial susceptibility profiles and presence of resistance genes in S. aureus strains isolated from milk and milk products. Methods: A cross-sectional study was conducted in the Arsi highlands, Oromia, Ethiopia from March 2022 to February 2023. A total of 503 milk and milk product samples were collected, comprising 259 raw milk, 219 cottage cheese, and 25 traditional yogurt samples. S. aureus isolation and coagulase-positive staphylococci enumeration were performed using Baird-Parker agar supplemented with tellurite and egg yolk. S. aureus was further characterized based on colony morphology, Gram stain, mannitol fermentation, catalase test, and coagulase test. Phenotypic antimicrobial resistance was assessed using the Kirby–Bauer disc diffusion method, while the polymerase chain reaction (PCR) was employed for confirming the presence of S. aureus and detecting antimicrobial resistance genes. Results: S. aureus was detected in 24.9% of the milk and milk products, with the highest occurrence in raw milk (40.9%), followed by yogurt (20%), and cottage cheese (6.4%). The geometric mean for coagulase-positive staphylococci counts in raw milk, yogurt, and cottage cheese was 4.6, 3.8, and 3.2 log10 CFU/mL, respectively. Antimicrobial resistance analysis revealed high levels of resistance to ampicillin (89.7%) and penicillin G (87.2%), with 71.8% of the isolates demonstrating multidrug resistance. Of the 16 S. aureus isolates analyzed using PCR, all were found to carry the nuc gene, with the mecA and blaZ genes detected in 50% of these isolates each. Conclusion: This study revealed the widespread distribution of S. aureus in milk and milk products in the Arsi highlands of Ethiopia. The isolates displayed high resistance to ampicillin and penicillin, with a concerning level of multidrug resistance. The detection of the mecA and blaZ genes in selected isolates is of particular concern, highlighting a potential public health hazard and posing a challenge to effective antimicrobial treatment. These findings highlight the urgent need to enhance hygiene standards in milk and milk product handling and promote the rational use of antimicrobial drugs. Provision of adequate training for all individuals involved in the dairy sector can help minimize contamination. These measures are crucial in addressing the threats posed by S. aureus, including methicillin-resistant strains, and ensuring the safety of milk and its products for consumers. [ABSTRACT FROM AUTHOR]

Escherichia coli is a major foodborne pathogen worldwide. This study was conducted to assess the prevalence, risk factors, and antimicrobial susceptibility of E. coli and E. coli O157 in milk and milk products and hygienic practices in West Shoa, Oromia, Ethiopia. Five hundred fifty-six milk samples comprising 421 udder milk, 57 bulk tank milk, and 78 milk products were investigated. Moreover, a questionnaire was administered to 145 participants to assess hygienic practices. A standard microbiological procedure was used to detect E. coli and E. coli O157. The Kirby Bauer disc diffusion method was used to test the antimicrobial susceptibility of the isolates. Petri film plates were used to enumerate the coliform in raw bulk tank milk. Farm and animal-level E coli prevalence were estimated and association with risk factors was assessed. Escherichia coli was detected in 33.8% (95% confidence interval (CI) 29.9–37.9%) of the samples, of which only one isolate (0.2%) was E. coli O157. Escherichia coli contamination was higher in bulk tank samples (47.4%; 95% CI 34.0–61.0%) than in udder milk (34.7%; CI 30.1–39.4%), cottage cheese (27.0%; 95% CI 14.6–43.9%), and yoghurt 10.5% (95% CI 2.9–24.8%). For the animal-level E. coli contamination, only the study area was identified as a risk factor. Risk factors such as types of milk containers, udder washing practices, hygiene, and management systems were associated with both farm-level and milk products E. coli contamination. Most (59.0%) of the farmers practice udder washing only before milking and the remaining did not practice udder washing at all. The mean coliform count in raw bulk tank milk was higher than the international standard (4.09 log10 CFU/ml). All the 42 E. coli isolates tested were multidrug resistant. The occurrence of E. coli is high, while that of E. coli O157 is too low. The milk-handling practices are poor in the study areas. The high prevalence of E. coli, as well as the high coliform count and higher multi-drug resistance may pose risk to public health and food safety. Therefore, proper hygienic practices throughout the milk chain as well as rational drug use are advised. [ABSTRACT FROM AUTHOR]

Escherichia coli is a major foodborne pathogen worldwide. This study was conducted to assess the prevalence, risk factors, and antimicrobial susceptibility of E. coli and E. coli O157 in milk and milk products and hygienic practices in West Shoa, Oromia, Ethiopia. Five hundred fifty-six milk samples comprising 421 udder milk, 57 bulk tank milk, and 78 milk products were investigated. Moreover, a questionnaire was administered to 145 participants to assess hygienic practices. A standard microbiological procedure was used to detect E. coli and E. coli O157. The Kirby Bauer disc diffusion method was used to test the antimicrobial susceptibility of the isolates. Petri film plates were used to enumerate the coliform in raw bulk tank milk. Farm and animal-level E coli prevalence were estimated and association with risk factors was assessed. Escherichia coli was detected in 33.8% (95% confidence interval (CI) 29.9–37.9%) of the samples, of which only one isolate (0.2%) was E. coli O157. Escherichia coli contamination was higher in bulk tank samples (47.4%; 95% CI 34.0–61.0%) than in udder milk (34.7%; CI 30.1–39.4%), cottage cheese (27.0%; 95% CI 14.6–43.9%), and yoghurt 10.5% (95% CI 2.9–24.8%). For the animal-level E. coli contamination, only the study area was identified as a risk factor. Risk factors such as types of milk containers, udder washing practices, hygiene, and management systems were associated with both farm-level and milk products E. coli contamination. Most (59.0%) of the farmers practice udder washing only before milking and the remaining did not practice udder washing at all. The mean coliform count in raw bulk tank milk was higher than the international standard (4.09 log10 CFU/ml). All the 42 E. coli isolates tested were multidrug resistant. The occurrence of E. coli is high, while that of E. coli O157 is too low. The milk-handling practices are poor in the study areas. The high prevalence of E. coli, as well as the high coliform count and higher multi-drug resistance may pose risk to public health and food safety. Therefore, proper hygienic practices throughout the milk chain as well as rational drug use are advised. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus is a contagious pathogen that can cause various diseases in both humans and animals. Antimicrobial-resistant S. aureus is becoming an extremely important global health problem. A cross-sectional study was conducted from December 2019 to May 2020 to assess the occurrence of S. aureus and its antimicrobial susceptibility profiles in milk and traditionally processed dairy products in selected subcities of Addis Ababa. A total of 255 dairy product samples (175 raw milk and 80 traditionally processed dairy products) were collected from farms and retail markets. Samples were cultured for S. aureus according to standard microbiology techniques, and the Kirby–Bauer disk diffusion method was used to assess antimicrobial susceptibility of isolates to a panel of 12 antimicrobials. Susceptibility to methicillin was determined based on the sensitivity of isolates to cefoxitin, and resistant isolates were investigated for the presence of mecA and mecC genes using PCR. Staphylococcus aureus was isolated from 43 (24.6%) of milk, 7 (17.5%) of yogurt, and 2 (5%) of cottage cheese. A significantly higher rate of contamination with S. aureus was recorded among milk samples compared to yogurt and cottage cheese (p = 0.019). Out of 52 S. aureus isolates investigated for susceptibility to 12 antimicrobials, 49 (94.2%) of the isolates were resistant to ampicillin and 42 (80.8%) to amoxicillin+clavulanic acid. Twenty (38.5%) of the isolates were methicillin-resistant S. aureus (MRSA) based on susceptibility to cefoxitin. However, only one of these isolates (5%) was positive for mecA gene, and none of them were positive for the mecC gene. There was no significant difference (p > 0.05) in the rate of occurrence of MRSA among isolates from different sources. In conclusion, this study demonstrated a significant level of contamination of milk and dairy products with S. aureus and most isolates were multidrug resistant. The occurrence of MRSA in raw milk and dairy products signifies a serious public health threat as the practice of consuming raw dairy products in the study area is widespread. The lack of agreement between phenotypic and genotypic detection of MRSA suggests the need for further study to identify the genetic basis for the observed resistance phenotype. [ABSTRACT FROM AUTHOR]

There are limited diversified dairy products manufactured in dairy industries, and an increased demand for diversified dairy products in Ethiopia. To this end, there is un-met demand for nutrient rich dairy diversified products. This research was conducted with the aim to perform product development and quality assessment of yogurt with some cereals and legumes with the implication for diversification of nutrient dense yoghurt products in order to explore market potential. Yoghurt enriched with cereals and legumes was investigated for nutritional, microbial, texture and viscosity analyses as well as sensory quality attributes. Yogurts were processed through inoculation of milk with Lactobacillus bulgaricus and Streptococcus thermophiles. Finger millet yogurt was significantly better in protein and minerals composition. Furthermore, fat and ash values were high in finger millet yogurt: 3.47 and 2.36 g 10²g-1; respectively. Common bean (Redwolaita variety) yoghurt had abundant concertation of calcium next to finger millet-yoghurt. The aerobic plate count (2.3x10² cfu ml-1), coliform (<1x10¹ cfu ml-1), yeasts and mold (<1x10¹ cfu ml-1) of yoghurt comply with the microbiological standard requirements. Pathogenic bacteria such as Salmonella, E. coli, S.aureus, Shigella spp and B.cereus were absent in all the yogurt samples. The processed yogurt products possessed complementary effect of nutrient enhancement which is driven from cereals and legumes. The product has very good acceptability by panelists and revealed excellent nutritional composition. The processing technology also provided high nutrient dense, acceptable in quality and microbiologically safe products. The results from the proximate, physico-chemical, microbiological, and texture and viscosity analyses indicate that yogurt with cereals and pulses possess good nutritional composition. The processing technology provided microbiologically non-hazardous end products, and the results from the sensory evaluation of revealed that value added products can be a potential dairy product that fit to the lifestyle of consumers and get accepted. These findings further suggest investors currently involved in the dairy sector can produce products that fit into consumers' lifestyle by pioneering technology transfer of this research output in order to capture the un-met consumer demand for safe, nutritious, affordable and proprietary nutrient dense yogurt production. [ABSTRACT FROM AUTHOR]

Cross-sectional research aimed to identify Staphylococcus aureus from milk, yoghurt, and cheese collected from selected towns in the west Showa zone was conducted from May 2020 to March 2021. The isolates were identified based on colony characterisation, Gram stain, and coagulase tests, and matrix assisted laser desorption/ionisation time-of-flight biotyper. The drug susceptibility test was conducted using the disk diffusion method. The presence of mecA , blaZ , and nuc genes was assessed by polymerase chain reaction. The data were analysed using SPSS Ver.20. The result revealed that S. aureus was identified in 20.3%, 14.9%, and 4.8% of milk, cheese, and yoghurt samples, respectively. The rate was significantly higher in milk (OR = 5.04), and in cheese (OR = 1.46) than in yoghurt (p < 0.05). All 24 tested isolates were resistant to penicillin, tetracycle, and oxytetracycline. The nuc gene was found in all 24 tested isolates but no mecA and blaZ genes were tested. [ABSTRACT FROM AUTHOR]

Aflatoxin M1 (AFM1) or milk toxin is a hydroxilated metabolite of aflatoxin B1 from a contaminated feed. This study investigated the occurrence of AFM1 in milk and milk products collected from Bishoftu town (one of the major milk producing place in Ethiopia). Milk (n = 108), cheese (82), yogurt (93) and butter (82) samples were collected both from industrial and local producers. From the 365 samples analyzed, 361 samples were positive for AFM1. Maximum value was in cottage cheese with a concentration of 5.580 ± 0.08 μg/kg and minimum was in butter of zero (Not detected) value. Comparing the mean level of AFM1 between the four dairy products; milk > cottage cheese > butter > yogurt. Considering the average daily intake of AFM1 obtained in this study and the current average milk consumption rate (19 L/year) in Ethiopian consumers, only adults are in the safe zone with TDI (Tolerable Daily Intake) of AFM1 (0.0002 μg/kg of body weight). But infants and young children might be more exposed to the toxin due to their higher consumption of milk and milk products in their diet. • 365 milk & milk products (cottage cheese, yogurt and butter) were tested for AFM1. • 361 samples were positive for AFM1 with cottage cheese with the maximum AFM1. • 244 of the samples were above the acceptable limit of 0.5 μg/kg. • AFM1 mean is in the order of milk > cottage cheese > butter > yogurt. • Only adults are in the safe zone to AFM1 exposure with the current concentration. [ABSTRACT FROM AUTHOR]