Beyene Takele, Hayishe Halefom, Gizaw Fikru, Beyi Ashenafi Feyisa, Abunna Fufa, Mammo Bedaso, Ayana Dinka, Waktole Hika, Abdi Reta Duguma
Department of Biomedical Sciences, College of Veterinary Medicine and Agriculture, Addis Ababa University, Bishoftu, Ethiopia.
Department of Pharmacology and Clinical Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
BMC Res Notes. 2017 Apr 28;10(1):171. doi: 10.1186/s13104-017-2487-y.
Staphylococcus species cause mastitis and wound infection in livestock and food poisoning in humans through ingestion of contaminated foods, including meat and dairy products. They are evolving pathogens in that they readily acquire drug resistance, and multiple drug-resistant (MDR) isolates are increasing in human and veterinary healthcare. Therefore, this study was conducted to evaluate the prevalence of Staphylococci and their drug resistance in dairy farms and abattoir settings of Addis Ababa.
In this cross-sectional study, 193 samples of milk, meat, equipment and humans working in the dairy farms and abattoir were collected (dairy farms = 72 and abattoir sources = 121). Staphylococcus isolation and identification at the species level was done according to ISO-6888-3 using biochemical characteristics. An antimicrobial susceptibility test was conducted for 43 of the isolates using 15 antimicrobial agents commonly used for humans and livestock by the Kirby Bauer disk diffusion method following CLSI guidelines.
Staphylococcus organism were isolated from 92 (47.7%) of the total 193 samples, 50% in the dairy farms and 46.3% in the abattoir. The isolated species were S. aureus (n = 31; 16.1%), S. intermedius (n = 21; 10.9%), S. hyicus (n = 16; 8.3%), and coagulase negative Staphylococcus (CNS) (n = 24; 12.4%). Gentamycin was effective drug as all isolates (n = 43; 100%) were susceptible to it and followed by kanamycin (n = 39; 90.7%). However, the majority of the isolates showed resistance to penicillin-G (95.3%), nalidixic acid (88.4%), cloxacillin (79.1%), vancomycin (65.1%) and cefoxitin (55.8%). Of the 15 S. aureus tested for drug susceptibility, 73.3% of them were phenotypically resistant to vancomycin (VRSA) and all of the 15 isolates showed multi-drug resistance (MDR) to >3 drugs. Also, all of the tested CNS (100%), S. hyicus (100%) and the majority of S. intermedius isolates (88.9%) developed MDR.
Alarmingly, the Staphylococcus isolates circulating in the dairy farms and abattoir in the study area harbor MDR. High level of Staphylococcus species isolation from personnel and equipment besides food (meat and milk) samples in dairy farms and abattoir settings reveals that the hygiene practice in the dairy farm and abattoir is substandard. Prudent drug use and improved hygienic practice is recommended in the dairy farms and abattoir to safeguard the public from the risk of acquiring infections and MDR pathogenic Staphylococcus.
葡萄球菌属可导致家畜患乳腺炎和伤口感染，还可通过摄入包括肉类和奶制品在内的受污染食物引发人类食物中毒。它们是不断进化的病原体，很容易获得耐药性，并且多重耐药（MDR）菌株在人类和兽医医疗保健领域日益增多。因此，本研究旨在评估亚的斯亚贝巴奶牛场和屠宰场环境中葡萄球菌的流行情况及其耐药性。
在这项横断面研究中，收集了193份来自奶牛场和屠宰场的牛奶、肉类、设备以及工作人员的样本（奶牛场样本72份，屠宰场样本121份）。根据ISO - 6888 - 3标准，利用生化特性在种水平上进行葡萄球菌的分离和鉴定。按照CLSI指南，采用Kirby Bauer纸片扩散法，使用15种常用于人和家畜的抗菌药物对43株分离株进行药敏试验。
在总共193份样本中，92份（47.7%）分离出葡萄球菌属细菌，其中奶牛场分离率为50%，屠宰场为46.3%。分离出的菌种有金黄色葡萄球菌（n = 31；16.1%）、中间葡萄球菌（n = 21；10.9%）、猪葡萄球菌（n = 16；8.3%）和凝固酶阴性葡萄球菌（CNS）（n = 24；12.4%）。庆大霉素是有效的药物，所有分离株（n = 43；100%）对其敏感，其次是卡那霉素（n = 39；90.7%）。然而，大多数分离株对青霉素 - G（95.3%）、萘啶酸（88.4%）、氯唑西林（79.1%）、万古霉素（65.1%）和头孢西丁（55.8%）耐药。在检测药敏的15株金黄色葡萄球菌中，73.3%在表型上对万古霉素耐药（VRSA），所有15株分离株对>3种药物表现出多重耐药（MDR）。此外，所有检测的CNS（100%）、猪葡萄球菌（100%）以及大多数中间葡萄球菌分离株（88.9%）都产生了MDR。
令人担忧的是，研究区域奶牛场和屠宰场中传播的葡萄球菌分离株具有MDR。除了食品（肉类和牛奶）样本外，在奶牛场和屠宰场环境中从人员和设备中分离出的葡萄球菌属细菌数量很高，这表明奶牛场和屠宰场的卫生规范不达标。建议在奶牛场和屠宰场谨慎用药并改善卫生规范，以保护公众免受感染和MDR致病性葡萄球菌风险的侵害。
