Olsen John Elmerdahl, Svensmark Birgitta, Agerskov Lene, Albrechtsen Maja, Olsen Rikke Heidemann
Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark.
LVK Veterinary Cattle Practice, Hobro, Denmark.
Vet Microbiol. 2025 Aug;307:110575. doi: 10.1016/j.vetmic.2025.110575. Epub 2025 Jun 6.
Diarrhoea in calves is one of the most common disease manifestations, particularly within the first weeks of life. In the present study, 392 diarrhetic faecal samples from calves 0-28 days old were obtained from Danish dairy farms through routine veterinary diagnostics. Bovine pathogens (Clostridium perfringens type A, B and C, Salmonella enterica serovar Dublin, coronavirus, rotavirus, Cryptosporidium parvum, Coccidia (Eimeria) and Escherichia coli F5) were detected and quantified by qPCR (Enterit4calves assay). In addition, samples were cultured to semi-quantify the level of E. coli. Samples were primarily obtained from calves within the first two weeks (∼90 % of the samples), reflecting this critical period for diarrhoea development. Overall, C. perfringens type A, rotavirus and C. parvum were the most prevalent pathogens, detected in 28-39 % of the samples, while coronavirus and E. coli F5 were found in less than five percent of the samples. The remaining pathogens were not detected by qPCR in any of the samples. Culturing demonstrated moderate to massive growth of E. coli in 75 % of the samples, independent of the age of the sampled calves. For all qPCR detected pathogens, except for coronavirus and E. coli F5, dual-infection with the presence of two pathogenic agents in the sample, was the most common infection type. In samples with more than one pathogen, the quantity of each pathogen according to Ct-value was not significantly different from quantity of the same pathogen in samples where it was the only pathogen. The importance of the high prevalence of non-F5 E. coli needs to be further clarified, in particular for the types of E. coli found in moderate to massive growth in fecal samples negative for all qPCR included pathogens.
犊牛腹泻是最常见的疾病表现之一，尤其是在出生后的头几周内。在本研究中，通过常规兽医诊断从丹麦奶牛场获取了392份0至28日龄腹泻犊牛的粪便样本。通过qPCR（Enterit4calves检测法）检测并定量牛病原体（A型、B型和C型产气荚膜梭菌、都柏林沙门氏菌、冠状病毒、轮状病毒、微小隐孢子虫、球虫（艾美耳属）和大肠杆菌F5）。此外，对样本进行培养以半定量大肠杆菌的水平。样本主要取自前两周内的犊牛（约占样本的90%），这反映了腹泻发展的关键时期。总体而言，A型产气荚膜梭菌、轮状病毒和微小隐孢子虫是最常见的病原体，在28%至39%的样本中被检测到，而冠状病毒和大肠杆菌F5在不到5%的样本中被发现。其余病原体在任何样本中均未通过qPCR检测到。培养结果显示，75%的样本中大肠杆菌呈中度至大量生长，与所采犊牛的年龄无关。对于所有qPCR检测到的病原体，除冠状病毒和大肠杆菌F5外，样本中存在两种病原体的双重感染是最常见的感染类型。在含有多种病原体的样本中，根据Ct值，每种病原体的数量与该病原体单独存在于样本中的数量无显著差异。非F5大肠杆菌高流行率的重要性需要进一步阐明，特别是对于在所有qPCR检测的病原体均为阴性的粪便样本中呈中度至大量生长的大肠杆菌类型。
