Department of Infectious Diseases and Preventive Medicine, Faculty of Veterinary Medicine, University of Life Sciences "King Mihai I" from Timişoara, Timişoara, Romania.
Department of Reproduction, Faculty of Veterinary Medicine, University of Life Sciences "King Mihai I" from Timişoara, Timişoara, Romania.
Vet Res Commun. 2024 Nov 22;49(1):30. doi: 10.1007/s11259-024-10579-7.
The present study investigates the prevalence and etiology of subclinical mastitis in Țurcana sheep flocks located in south-western Romania. Milchtest and California Mastitis Test (CMT), were used for the detection of subclinical mastitis. A number of 360 milk samples across three lactation phases were analyzed. Subclinical mastitis was identified in 146 (40.6%) of sheep milk samples. Only milk samples (n = 146) collected from sheep diagnosed with subclinical mastitis were considered for microbiological analyses. Thus, Staphylococcus aureus (129/146; 88.4%) was identified as the predominant pathogen followed by Streptococcus spp. (14/146; 9.6%) Enterococcus spp. (7/146; 4.8%), Pseudomonas aeruginosa (6/146; 4.1%) and Klebsiella pneumoniae (5/146; 3.4%). Antimicrobial susceptibility of isolated strains of Staphylococcus aureus, Streptococcus spp. and Enterococcus spp. was also tested. The results showed varying resistance patterns depending on the farm and microorganism. In heard A the highest resistance of Staphylococcus aureus was identified to polymyxin B (79.7%) followed by novobiocin (73.4%) and tetracycline (45.3%); Streptococcus spp. to streptomycin (100%), novobiocin (100%), tetracycline (100%) and Enterococcus spp. to tylosin (100%), streptomycin (75.0%) and tetracycline (75.0%). In herd B, Staphylococcus aureus showed high resistance rates to polymyxin B (86.3%), novobiocin (74.5%) and cloxacillin (39.2%); Streptococcus spp. strains to streptomycin (100%), novobiocin (100%), tetracycline (100%) and Enterococcus spp. to gentamicin (100%), streptomycin (66.7%) and erythromycin (66.7%). The obtained preliminary results indicate a potential risk that future treatments of sheep mastitis may not be effective, and demonstrated that raw unpasteurized milk can harbor antimicrobial resistance pathogens posing a threat to public health. However, further investigations involving molecular research on resistance genes are required to draw comprehensive conclusions.
本研究调查了罗马尼亚西南部图尔恰纳绵羊群中隐性乳腺炎的流行情况和病因。使用乳样加州乳房炎试验（CMT）检测隐性乳腺炎。分析了三个泌乳阶段的 360 个乳样。在 146 个（40.6%）绵羊乳样中发现了隐性乳腺炎。仅对诊断为隐性乳腺炎的绵羊的乳样（n=146）进行微生物分析。因此，金黄色葡萄球菌（129/146；88.4%）被确定为主要病原体，其次是链球菌属（14/146；9.6%）肠球菌属（7/146；4.8%）、铜绿假单胞菌（6/146；4.1%）和肺炎克雷伯菌（5/146；3.4%）。还测试了分离的金黄色葡萄球菌、链球菌属和肠球菌属菌株的抗菌药物敏感性。结果表明，根据农场和微生物的不同，存在不同的耐药模式。在 herd A 中，金黄色葡萄球菌对多粘菌素 B（79.7%）的耐药性最高，其次是新生霉素（73.4%）和四环素（45.3%）；链球菌属对链霉素（100%）、新生霉素（100%）、四环素（100%）和肠球菌属对泰乐菌素（100%）、链霉素（75.0%）和四环素（75.0%）。在 herd B 中，金黄色葡萄球菌对多粘菌素 B（86.3%）、新生霉素（74.5%）和氯唑西林（39.2%）的耐药率较高；链球菌属对链霉素（100%）、新生霉素（100%）、四环素（100%）和肠球菌属对庆大霉素（100%）、链霉素（66.7%）和红霉素（66.7%）。初步结果表明，未来治疗绵羊乳腺炎可能无效的风险，并且表明未经巴氏消毒的生牛奶可能携带对抗生素有耐药性的病原体，对公众健康构成威胁。然而，需要进一步进行涉及耐药基因的分子研究，以得出全面的结论。
