Penati Martina, Musa Laura, Filippone Pavesi Laura, Guaraglia Alessandro, Ulloa Fernando, Moroni Paolo, Piccinini Renata, Addis Maria Filippa
Department of Veterinary Medicine and Animal Sciences, University of Milan, 26900 Lodi, Italy.
Department of Humanities and Social Sciences, University of Sassari, 07100 Sassari, Italy.
Antibiotics (Basel). 2024 Mar 5;13(3):241. doi: 10.3390/antibiotics13030241.
This study investigated the presence, distribution, and antimicrobial resistance profiles of extended-spectrum beta-lactamase (ESBL)-producing in a dairy herd located in Northern Italy. The feces of clinically healthy calves, their mothers, and the cows treated for mastitis, as well as water, environmental samples, and waste milk were collected and subjected to bacteriological culture on CHROMagar ESBL plates. A questionnaire was administered to identify risk factors. The isolates were identified as by MALDI-TOF MS and subjected to the double-disk synergy test (DDST) and minimal inhibitory concentration (MIC) assay. As a result, ESBL was isolated from the feces of 28 of 37 (75.67%) calves, the feces of 2 of 3 (66.67%) treated cows, 8 of 14 (57.15%) environmental samples, and waste milk. All ESBL isolates showed multiple resistances and were categorized as multidrug-resistant (MDR). Several risk factors for ESBL selection and diffusion were identified, including lack of routine cleaning of calf feeding and housing equipment, administration of waste milk to male calves, and blanket dry cow therapy. In conclusion, this study highlighted the presence of MDR, ESBL in the feces of most dairy calves, and their association with different sample sources. Accordingly, adding to the prudent use of antibiotics, the adoption of adequate farm hygiene and biosecurity measures might also help prevent the spread and transmission of ESBL within the herd.
本研究调查了意大利北部一个奶牛场中产超广谱β-内酰胺酶（ESBL）细菌的存在情况、分布及抗菌药物耐药谱。采集了临床健康犊牛、其母亲以及接受乳腺炎治疗的奶牛的粪便，还有水、环境样本和废乳，并在CHROMagar ESBL平板上进行细菌培养。发放问卷以确定风险因素。通过基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）鉴定分离株，并进行双纸片协同试验（DDST）和最低抑菌浓度（MIC）测定。结果，从37头犊牛中的28头（75.67%）粪便、3头接受治疗奶牛中的2头（66.67%）粪便、14份环境样本中的8份（57.15%）以及废乳中分离出了ESBL。所有ESBL分离株均表现出多重耐药性，被归类为多重耐药（MDR）。确定了几个ESBL选择和传播的风险因素，包括犊牛饲养和圈舍设备缺乏常规清洁、给雄性犊牛投喂废乳以及普遍的干奶牛治疗。总之，本研究突出了大多数奶牛犊粪便中存在多重耐药的ESBL及其与不同样本来源的关联。因此，除了谨慎使用抗生素外，采取适当的农场卫生和生物安全措施可能也有助于防止ESBL在牛群中的传播。
