title: Short communication: Streptococcus canis is able to establish a persistent udder infection in a dairy herd.
abstract: Bovine mastitis caused by Streptococcus canis is relatively rare. Consequently, many epidemiologic aspects of the infection, including factors that mediate crossing of host species barriers by the pathogen, infectiousness of the microorganism to the mammary gland, and the course of the disease within a herd, are still not elucidated. Therefore, the aim of the present study was to describe results of a 15-mo observation of subclinical Strep. canis mastitis on a dairy farm housing 76 lactating Holstein-Friesian cows. Upon 3 visits to the farm during a period between April 2013 and June 2014, Strep. canis was cultured from milk samples of 17 (22.4% of the herd), 7 (9.6%), and 8 (11.3%) cows, respectively. The isolates obtained were characterized phenotypically by means of the API Strep identification kit (bioMérieux, Marcy l'Etoile, France), as well as genetically by using random amplified polymorphic DNA and macrorestriction analysis of the chromosomal DNA by pulsed-field gel electrophoresis. All strains displayed the same biochemical features, and the molecular methods revealed that the isolates belonged to a single clone or were very closely related. Results of the study indicate that Strep. canis is capable of causing intramammary infections of long duration, behaving in a contagious manner. Because a persistently infected cow may serve as the source of Strep. canis infection for other animals, effective control of this type of udder infection within a herd may require similar measures to those adopted in Streptococcus agalactiae eradication programs.
authors.affiliation: Wroclaw University of Environmental and Life Sciences, Faculty of Veterinary Medicine, 50-375 Wrocław, Poland; Department of Pathology, St. Norwida 31, 50-375 Wrocław, Poland. Electronic address: jaroslaw.krol@up.wroc.pl.
authors.forename: Jarosław
authors.initials: J
authors.lastname: Król
authors.affiliation: Wroclaw University of Environmental and Life Sciences, Faculty of Veterinary Medicine, 50-375 Wrocław, Poland; Department of Reproduction and Clinic of Farm Animals, Pl. Grunwaldzki 49, 50-366 Wrocław, Poland.
authors.forename: Jan
authors.initials: J
authors.lastname: Twardoń
authors.affiliation: Wroclaw University of Environmental and Life Sciences, Faculty of Veterinary Medicine, 50-375 Wrocław, Poland; Department of Reproduction and Clinic of Farm Animals, Pl. Grunwaldzki 49, 50-366 Wrocław, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Mrowiec
authors.affiliation: Wroclaw University of Environmental and Life Sciences, Faculty of Veterinary Medicine, 50-375 Wrocław, Poland; Department of Food Hygiene and Consumer Health Protection, St. Norwida 31, 50-375 Wrocław, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Podkowik
authors.affiliation: Wroclaw University of Environmental and Life Sciences, Faculty of Veterinary Medicine, 50-375 Wrocław, Poland; Department of Reproduction and Clinic of Farm Animals, Pl. Grunwaldzki 49, 50-366 Wrocław, Poland.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Dejneka
authors.affiliation: Warsaw University of Life Sciences, St. Nowoursynowska 166, 02-787 Warsaw, Poland.
authors.forename: Bogdan
authors.initials: B
authors.lastname: Dębski
authors.affiliation: Military University of Technology, St. Gen. Kaliskiego 2, 00-908 Warsaw, Poland.
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Nowicki
authors.affiliation: Wroclaw University of Environmental and Life Sciences, Faculty of Veterinary Medicine, 50-375 Wrocław, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Zalewski
mesh_terms: D000818:Animals; D002417:Cattle; D004269:DNA, Bacterial / Q000032:analysis; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005602:France; D007774:Lactation; D008321:Mammary Glands, Animal; D008414:Mastitis, Bovine / Q000382:microbiology* / Q000517:prevention & control; D008892:Milk; D013290:Streptococcal Infections / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D013291:Streptococcus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial
keywords: Streptococcus canis; cattle; mastitis; pulsed-field gel electrophoresis; random amplified polymorphic DNA