Staphylococcus aureus is a pathogenic bacterium-contaminating milk and milk products causing food poisoning primarily due to its enterotoxins. The study aimed at estimating the prevalence of S. aureus in milk and milk products, assessing potential risk factors for contamination, and determining the load and the antimicrobial susceptibility profile of the isolates. A cross-sectional study design was employed to collect a total of 486 samples, comprising 383 raw milk, 47 bulk tank milk, 29 curd milk (Ergo), and 28 Ethiopian cottage cheese (Ayib) samples. Enumeration, isolation, and identification of S. aureus were carried out following standard microbiological techniques. Antibiogram was performed using 12 antimicrobials following the KirbyBauer disc diffusion method. Logistic regression analyses were used to assess the association between the occurrence of S. aureus in milk and milk products and potential risk factors. The overall prevalence of S. aureus was 10.69 (52/486) [95 confidence interval (CI):8.0913.79]. The prevalence of S. aureus in raw milk, curd milk, bulk tanks at the farm, bulk tanks at milk collection facilities, and cottage cheese was 8.64, 24.14, 14.73, 23.08, and 14.29, respectively. The rate of isolation of S. aureus was significantly high in curd milk than in other types of samples (P=0.010). The study revealed that teat washing (OR: 4.93, 95 CI: 2.0611.81), use of towel (OR: 12.13, 95 CI: 3.7439.29), and tick infestations (OR: 4.31, 95 CI: 1.2814.44) were risk factors associated with the occurrence of S. aureus in milk. About 48.39 of the milk samples assessed had the S. aureus count higher than 10⁵CFU/ml. The highest rate of resistance was observed to ampicillin (95), amoxicillin (95), oxacillin (87.5), and cefotaxime (80). All isolates are resistant to at least two classes of antimicrobial drugs, while 65.0 of the isolates were found to be multidrug-resistant. The moderate prevalence, high load, and antimicrobial resistance of S. aureus indicate the higher public health risk due to the widespread consumption of raw milk in the area. Good hygienic practices, regular surveillance of antimicrobial resistance, and prudent use of drugs are suggested.

Antimicrobial resistance to commercially available medications has become a global issue, yet there is still the possibility of developing new drugs from medicinal plants. As a result, the aims of the present study were to screen secondary metabolites and to evaluate in vitro antifungal activities of Brucea antidysenterica, Aloe vera, and Justicia schimperiana. After the plants were identified, their leaves were collected, washed, dried under the shade, pulverized, and extracted with methanol (99.8) using the maceration technique. The presence of secondary metabolites in plant extracts was screened using various laboratory protocols. The antifungal activities of the plant extract against reference fungal strains of Candida albicans and Aspergillus niger at concentrations of 200, 100, and 50mg/mL were assessed using the agar-well diffusion method. Ketoconazole (15μg) was used as a positive control, while 5 dimethyl sulfoxide and/or 5 Tween 80 were used as negative controls. All tests were conducted in triplicate. Alkaloids, flavonoids, and phenols were secondary metabolites found in all plant extracts. The extract of leaves of B. antidysenterica and J. schimperiana formed a mean zone of inhibition of 15.5±0.5mm and 15.3±0.58mm, respectively, against Candida albicans at a concentration of 200mg/mL, whereas extracts of A. vera leaves formed a 12.3±0.58mm inhibition zone only against Aspergillus niger at 200mg/mL. In conclusion, the current study found that B. antidysenterica, A. vera, and J. schimperiana had antifungal activity. In addition, all these plants had a variety of secondary metabolites that possibly have antifungal activities. Studies on in vivo investigations and isolation of specific antifungal compounds from these medicinal plants are suggested.

Escherichia coliis a major foodborne pathogen worldwide. This study was conducted to assess the prevalence, risk factors, and antimicrobial susceptibility ofE. coliandE. coliO157 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 detectE. coliandE. coliO157. 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-levelE coliprevalence were estimated and association with risk factors was assessed.Escherichia coliwas detected in 33.8% (95% confidence interval (CI) 29.9–37.9%) of the samples, of which only one isolate (0.2%) wasE. coliO157.Escherichia colicontamination 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-levelE. colicontamination, 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 productsE. colicontamination. 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 42E. coliisolates tested were multidrug resistant. The occurrence ofE. coliis high, while that ofE. coliO157 is too low. The milk-handling practices are poor in the study areas. The high prevalence ofE. 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.

Purpose: Mastitis is one of the major global problems severely affecting the dairy sector. Staphylococcus species are the primary bacteria consistently identified from mastitic milk. This study was aimed to estimate the prevalence of mastitis, isolate Staphylococcus species, determine risk factors, and the antimicrobial susceptibility profile of Staphylococcus species from mastitic Zebu cows in West Shewa Zone, Ethiopia. Materials and Methods: A total of 404 lactating Zebu cows were tested for mastitis. Isolation and identification of Staphylococcus from mastitis positive samples were done by bacteriological culture and biochemical tests. Further identification of coagulase-negative Staphylococcus (CNS) species and antimicrobial susceptibility test of the Staphylococcus aureus and the CNS was done by the Phoenix machine. Descriptive statistics was used to summarize the prevalence of mastitis while the Chi-square test and logistic regression were used to determine the association between the prevalence of mastitis and the risk factors and the magnitude of association, respectively. Results: The present study showed an overall cow and quarter level mastitis prevalence of 30.5% (95% confidence interval [CI]:26.0– 35.2) and 8.3% (95% CI 7.0– 9.8), respectively. The quarter level isolation rate of Staphylococcus species was 38.6% (95% CI: 30.1– 47.6). Five Staphylococcus species namely S. intermedius, S. hyicus, S. aureus, S. lentus, and S. sciuri were identified. The latter two are CNS and were identified for the first time in Ethiopia. Antimicrobial susceptibility testing showed none of the isolates of S. aureus, 100% of S. sciuri, and 87.5% of S. lentus species were multidrug-resistant. The independent predictors of mastitis (p< 0.05) were the age of the cows, stage of lactation, type of housing, the interval of bedding cleaning, and previous history of mastitis. Conclusion: The study showed a high prevalence of mastitis, Staphylococcus species, and multidrug resistant S. lentus, and S. sciuri in Zebu cows.

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 ( ). 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 ( ) and no knowledge ( ) 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.

Background: Although traditional healers in Ethiopia have a long history of using medicinal plants to treat diseases in animals and humans, studies on the antibacterial activities and potential bioactive ingredients of most medicinal plants have been insufficient. Therefore, this study aimed to evaluate the in-vitro antibacterial activities and to screen phytochemical constituents of selected medicinal plants against reference bacterial strains. Methods: The fresh and healthy roots of Echinops amplexicaulis, fruits of Ruta chalepensis, and leaves of Salix subserrata were collected from West Shewa Zone, Ethiopia. Agar well diffusion and agar dilution methods were used to evaluate antibacterial activities and minimum inhibitory concentrations (MIC). All the crude plant extracts were tested against Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli and Pseudomonas aeruginosa at concentrations of 100, 50, and 25 mg/mL in each triplet (3x). MIC of crude extracts ranging from 1.5625 to 12.50 mg/mL was applied to all bacterial strains. The positive control was ciprofloxacin disk (5 μg) and the negative control was 5% dimethyl sulfoxide. The presence of secondary metabolites of each crude extract was screened. The group means comparisons were done using one-way ANOVA and results were presented as mean ± standard deviation. Results: Although all selected plant extracts had shown antibacterial activities, methanol extracts had a greater zone of inhibition against all reference bacterial strains when compared to petroleum ether extracts. The growth of P. aeruginosa was inhibited at a minimum concentration of both methanol and petroleum extracts (1.5625 mg/mL) when compared to the remaining bacterial strains. Phytochemical screening showed that saponins and alkaloids were found in all crude plant extracts, while phytosterol was meager. Conclusion: This study revealed that all tested plants had significant secondary metabolites and antibacterial activities against reference bacterial strains.