title: A Metataxonomic Approach Could Be Considered for Cattle Clinical Mastitis Diagnostics.
abstract: Mastitis is one of the most costly diseases affecting the dairy industry, and identification of the causative microorganism(s) is essential. Here, we report the use of next-generation sequencing of bacterial 16S rRNA genes for clinical mastitis diagnosis. We used 65 paired milk samples, collected from the mastitic and a contralateral healthy quarter of mastitic dairy cattle to evaluate the technique as a potential alternative to bacterial culture or targeted PCR. One large commercial dairy farm was used, with one trained veterinarian collecting the milk samples. The 16S rRNA genes were individually amplified and sequenced using the MiSeq platform. The MiSeq Reporter was used in order to analyze the obtained sequences. Cattle were categorized according to whether or not 1 of the 10 most abundant bacterial genera in the mastitic quarter exhibited an increase in relative abundance between the healthy and mastitic quarters equal to, or exceeding, twofold. We suggest that this increase in relative abundance is indicative of the genus being a causative mastitis pathogen. Well-known mastitis-causing pathogens such asStreptococcus uberisandStaphylococcusspp. were identified in most cattle. We were able to diagnose 53 out of the 65 studied cases and identify potential new mastitis pathogens such asSneathia sanguinegensandListeria innocua, which are difficult to identify by bacterial culture because of their fastidious nature.
authors.affiliation: Department of Livestock Health and Welfare, Institute of Veterinary Science, University of Liverpool , Neston , UK.
authors.forename: Joanne W H
authors.initials: JW
authors.lastname: Oultram
authors.affiliation: Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University , Ithaca, NY , USA.
authors.forename: Erika K
authors.initials: EK
authors.lastname: Ganda
authors.affiliation: Department of Livestock Health and Welfare, Institute of Veterinary Science, University of Liverpool , Neston , UK.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Boulding
authors.affiliation: Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University , Ithaca, NY , USA.
authors.forename: Rodrigo C
authors.initials: RC
authors.lastname: Bicalho
authors.affiliation: Department of Livestock Health and Welfare, Institute of Veterinary Science, University of Liverpool, Neston, UK; Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA; Department of Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Neston, UK.
authors.forename: Georgios
authors.initials: G
authors.lastname: Oikonomou
keywords: cattle; diagnostics; mastitis; metataxonomics; sequencing