美国田纳西州奶牛场散装罐牛奶中牛支原体分离株的流行情况及全基因组序列分析
Prevalence and Whole Genome Sequence Analysis of Mycoplasma bovis Isolates From Bulk Tank Milk of Dairy Farms in Tennessee, USA.
作者信息
Gelgie Aga E, Gelalcha Benti D, Christensen Daniel, Freeman Trevor, Beever Jonathan E, Dego Oudessa Kerro
机构信息
Department of Animal Science, University of Tennessee Institute of Agriculture, Knoxville, Tennessee, USA.
Department of Biomedical Science, College of Veterinary Medicine and Agriculture, Addis Ababa University, Bishoftu, Ethiopia.
出版信息
J Vet Intern Med. 2025 Jul-Aug;39(4):e70164. doi: 10.1111/jvim.70164.
BACKGROUND
Mycoplasma bovis mastitis is an important disease of dairy cows that causes substantial economic losses. However, its prevalence in different states in the United States (US), including Tennessee, is not well known. Furthermore, recent studies showed a high prevalence of bovine hemotropic mycoplasmas in US dairy farms.
OBJECTIVES
Determine the prevalence of M. bovis in bulk tank milk (BTM) of dairy farms in Tennessee and evaluate the genetic diversity, virulence factors, and antimicrobial resistance genes of the identified isolates. In addition, the prevalence of Mycoplasma wenyonii and Candidatus Mycoplasma haemobos in the bulk tank milk was determined.
METHODS
Seventy-five BTM samples were collected from 59 dairy farms. Of the 59 farms, 56 are in Tennessee and the remaining 3 farms are in the neighboring states, Georgia (n = 2) and Alabama (n = 1). Milk samples were tested using bacterial culture, PCR, and qPCR. M. bovis isolates were genetically characterized by pangenome analysis.
RESULTS
Of the 56 farms, 3 (5.3%) were positive for M. bovis by bacterial culture and 43 (76.7%) were positive by PCR. Pangenome analysis showed clustering of current isolates with mastitis isolates from the US, Israel, and Europe. Of 75 BTM samples tested by qPCR, 42 (56%) and 51 (68%) were positive for M. wenyonii and C. M. haemobos, respectively.
CONCLUSIONS
M. bovis intramammary infection is prevalent in Tennessee dairy farms.
背景
牛支原体乳腺炎是奶牛的一种重要疾病，会造成重大经济损失。然而，其在美国不同州（包括田纳西州）的流行情况尚不清楚。此外，最近的研究表明美国奶牛场中牛血支原体的流行率很高。
目的
确定田纳西州奶牛场散装罐奶（BTM）中牛支原体的流行率，并评估已鉴定分离株的遗传多样性、毒力因子和抗菌抗性基因。此外，还确定了散装罐奶中温扬氏支原体和嗜血性支原体的流行率。
方法
从59个奶牛场收集了75份BTM样本。在这59个农场中，56个位于田纳西州，其余3个农场位于邻近州，佐治亚州（n = 2）和阿拉巴马州（n = 1）。使用细菌培养、PCR和qPCR对牛奶样本进行检测。通过全基因组分析对牛支原体分离株进行遗传特征分析。
结果
在56个农场中，3个（5.3%）通过细菌培养检测出牛支原体呈阳性，43个（76.7%）通过PCR检测呈阳性。全基因组分析表明，当前分离株与来自美国、以色列和欧洲的乳腺炎分离株聚类。在通过qPCR检测的75份BTM样本中，分别有42份（56%）和51份（68%）温扬氏支原体和嗜血性支原体呈阳性。
结论
牛支原体乳房内感染在田纳西州奶牛场中普遍存在。
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