title: Intramammary infection with coagulase-negative staphylococci at parturition: Species-specific prevalence, risk factors, and effect on udder health.
abstract: Coagulase-negative staphylococci (CNS) are the main cause of bovine intramammary infections (IMI) in many countries. Despite a high prevalence of CNS IMI at parturition, species-specific risk factor studies, relying on accurate identification methods, are lacking. Therefore, this observational study aimed at determining the prevalence and distribution of different CNS species causing IMI in fresh heifers and dairy cows in Flemish dairy herds and identifying associated species- and subgroup-specific risk factors at the herd, cow, and quarter level. The effect on udder health was investigated as well. Staphylococcus chromogenes, S. sciuri, and S. cohnii were the most frequently isolated species. The only CNS species causing IMI in fresh heifers and dairy cows in all herds was Staphylococcus chromogenes, whereas large between-herd differences in distribution were observed for the other species. Quarters from heifers and quarters with an inverted teat end had higher odds of being infected with S. chromogenes, S. simulans, or S. xylosus as well as with S. chromogenes solely. Prepartum teat apex colonization with S. chromogenes increased the likelihood of S. chromogenes IMI in the corresponding quarters at parturition. Quarters with dirty teat apices before calving were more likely to be infected with S. cohnii, S. equorum, S. saprophyticus, or S. sciuri, supporting the environmental nature of these CNS species. Three species (S. chromogenes, S. simulans, and S. xylosus) were associated with a higher quarter somatic cell count at parturition as compared with uninfected quarters.
authors.affiliation: M-team and Mastitis and Milk Quality Research Unit, Department of Reproduction, Obstetrics, Herd Health, Ghent University, 9820 Merelbeke, Belgium. Electronic address: Anneleen.Devisscher@UGent.be.
authors.forename: A
authors.initials: A
authors.lastname: De Visscher
authors.affiliation: M-team and Mastitis and Milk Quality Research Unit, Department of Reproduction, Obstetrics, Herd Health, Ghent University, 9820 Merelbeke, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: Piepers
authors.affiliation: Department of Pathology, Bacteriology, and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium.
authors.forename: F
authors.initials: F
authors.lastname: Haesebrouck
authors.affiliation: M-team and Mastitis and Milk Quality Research Unit, Department of Reproduction, Obstetrics, Herd Health, Ghent University, 9820 Merelbeke, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: De Vliegher
mesh_terms: D000818:Animals; D002417:Cattle; D003030:Coagulase / Q000378:metabolism; D005260:Female; D008321:Mammary Glands, Animal; D008414:Mastitis, Bovine / Q000453:epidemiology* / Q000382:microbiology; D008892:Milk; D015995:Prevalence; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000662:veterinary; D013210:Staphylococcus
chemical_list: D003030:Coagulase
keywords: coagulase-negative staphylococci; dairy cattle; mastitis; risk factor