RESUMO
Background: Antibiotics are among the most widely used drugs in farm animals for therapeutic and prophylactic purposes. However, the antibiotic residues in meat are a serious public health concern due to their harmful effects on consumer health. Besides this problem, there is limited information on the level of the antibiotic residues, including tetracycline residues. Therefore, this study was aimed to determine the tetracycline residues in the kidney and muscle samples of beef cattle in Harar town and Dire Dawa city. Methods: A study was conducted on 500 randomly selected carcass (250 kidney and 250 muscle samples) slaughtered at Dire Dawa and Harar municipal slaughterhouses between December 2018 and December 2019. The samples were collected aseptically and screened for tetracycline residues by thin layer chromatography. Then, presumptive positive samples were analyzed using high-performance liquid chromatography to get a quantitative outcome. Descriptive statistics were used to determine the frequency, mean, or standard deviation to determine the summary values and distribution of the outcomes. Finally, the data was analyzed using SPSS version 21 software. Results: Out of 500 samples, oxytetracycline residues were detected in 84% of the samples. However, tetracycline and doxycycline were not detected in all samples. Among the kidney and muscle samples collected from Dire Dawa and Harar abattoirs, 109 (87.2%) and 101 (80.8%) were positive for oxytetracycline, respectively. Oxytetracycline residue levels in Dire Dawa ranged from 57 to 607 µg/kg for the kidney and 10.14 to 435 µg/kg for muscle samples. Among the samples collected from Harar, the concentration of oxytetracycline residues ranged from 16 to 433 µg/kg and 6 to 435 µg/kg for kidney and muscle samples, respectively, at Harar slaughterhouses. About 22.0% of muscle samples collected from Dire Dawa and 17.8% from Harar town had oxytetracycline residues above maximum residue limits. Conclusions: In general, the study revealed that oxytetracycline residues were prevalent among tetracycline residues analyzed from kidney and muscle samples in the study areas. Thus, there is a risk of consumer exposure to these antibiotic residues that may have human health effects. Therefore, awareness creation and strict regulation is needed by the regulatory authorities for the use of antimicrobial drugs in the livestock industry.
RESUMO
A cross-sectional study was conducted to estimate the prevalence of Staphylococcus aureus in raw milk and swab, to assess the antimicrobial susceptibility profile, milk handling practice, and its associated risk factors in selected dairy farms of Mukaturi and Sululta Town, Oromia Region, Ethiopia. A total of 247 samples collected from dairy farms were examined using standard microbiological techniques. The antimicrobial susceptibility profiles of the isolates were also investigated. The possible risk factors for Staphylococcus aureus contaminations in milk were evaluated through a structured questionnaire. Overall, 16.6% (n= 41) of the samples were positive for S. aureus. The prevalence of S. aureus was 15.3% from udder milk and 25%, 20%, and 10% from milkers' hand, milking bucket, and drying towel swab, respectively. The prevalence of Staphylococcus aureus in milk showed statistically significant variation with respect to age (p≤ 0.001), parity (P≤ 0.001), drainage condition of milking area (P=0.035), study sites (P=0.035), and management system (P=0.035). Majority of the isolates were found resistant to penicillin G (97.6%) and amoxicillin (43.9%). According to this study, 12/28(42.9%) Staphylococcus aureus positive raw milk samples had 104-105cfu/ml S. aureus count, which is above the recommended level for human consumption. 47.1% of milking persons store milk at room temperature temporarily (between 6 and 12 hrs) till transport to collection center with no means of cooling aid. From consumers 25.6% had no health risk associated with raw milk consumption or aware of milk borne disease associated with drinking raw milk. Thus, 60.5% of milk users had habit of raw milk consumption. The study revealed a prevalence of S. aureus, poor milk handling practices, raw milk consumption behavior in study area. Proper handling and hygiene decrease milk contamination by S. aureus and make it safe for human consumption.
RESUMO
A cross-sectional study was conducted from October 2014 to July 2015 to determine the prevalence and populations of E. coli as well as the prevalence and antimicrobial susceptibility of E. coli O157:H7 isolated from raw milk. Biochemical and serological tests methods were used to confirm E. coli and E. coli O157:H7 and isolates were subjected to antimicrobial susceptibility test using the agar disc diffusion method. Out of 380 raw milk samples examined, 129 (33.9%) and 11 (2.9%) were contaminated with E. coli and E. coli O157:H7, respectively. The highest prevalence was recorded in samples obtained from vendors (39.1%, 4.978 ± 0.180 log10/ml) compared with samples from farmers (28.1%, 3.93 ± 0.01 log10/ml) with significant differences (P = 0.02). The frequency of contamination was higher in the samples collected from milk that was stored and transported in plastic containers (39.4%) than in the containers made of stainless steel (23.0%) (P = 0.002). The antimicrobial susceptibility profile showed that E. coli O157:H7 were resistant to tetracycline (81.8%), streptomycin (81.8%), and kanamycin (63.6%). Milk samples were produced and handled under poor hygienic conditions, stored, and transported in inappropriate containers and under temperature abuse conditions leading to high health risk to the consumers. Additional studies would be needed to establish association between the occurrences of E. coli O157:H7 in raw milk and all the risk factors involved in and around Asosa town.
