title: Genomic and transcriptomic comparison between Staphylococcus aureus strains associated with high and low within herd prevalence of intra-mammary infection.
abstract: BACKGROUND
  Staphylococcus aureus (Staph. aureus) is one of the major pathogens causing mastitis in dairy ruminants worldwide. The chronic nature of Staph. aureus infection enhances the contagiousness risk and diffusion in herds. In order to identify the factors involved in intra-mammary infection (IMI) and diffusion in dairy cows, we investigated the molecular characteristics of two groups of Staph. aureus strains belonging to ST8 and ST398, differing in clinical properties, through comparison of whole genome and whole transcriptome sequencing.
  
  
  RESULTS
  The two groups of strains, one originated from high IMI prevalence herds and the other from low IMI prevalence herds, present a peculiar set of genes and polymorphisms related to phenotypic features, such as bacterial invasion of mammary epithelial cells and host adaptation. Transcriptomic analysis supports the high propensity of ST8 strain to chronicity of infection and to a higher potential cytotoxicity.
  
  
  CONCLUSIONS
  Our data are consistent with the invasiveness and host adaptation feature for the strains GTB/ST8 associated to high within-herd prevalence of mastitis. Variation in genes coding for surface exposed proteins and those associated to virulence and defence could constitute good targets for further research.
authors.affiliation: Istituto di Biologia e Biotecnologia Agraria, CNR, via Einstein, 26900, Lodi, Italy. e.capra@ibba.cnr.it.
authors.forename: E
authors.initials: E
authors.lastname: Capra
authors.affiliation: Istituto di Biologia e Biotecnologia Agraria, CNR, via Einstein, 26900, Lodi, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Cremonesi
authors.affiliation: Istituto di Tecnologie Biomediche, CNR, Via Fratelli Cervi 93, 20090, Segrate, Milano, Italy.|Istituto Nazionale di Genetica Molecolare "Romeo ed Enrica Invernizzi", Via Francesco Sforza 35, 20122, Milan, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Pietrelli
authors.affiliation: Istituto di Tecnologie Biomediche, CNR, Via Fratelli Cervi 93, 20090, Segrate, Milano, Italy.|Scuola di Dottorato in Medicina Molecolare e Traslazionale, Università di Milano, Segrate, Milan, 20009, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Puccio
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia, Sezione di Lodi, via Einstein, 26900, Lodi, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Luini
authors.affiliation: Istituto di Biologia e Biotecnologia Agraria, CNR, via Einstein, 26900, Lodi, Italy.|Parco Tecnologico Padano, Via Einstein, 26900, Lodi, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Stella
authors.affiliation: Istituto di Biologia e Biotecnologia Agraria, CNR, via Einstein, 26900, Lodi, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Castiglioni
mesh_terms: D000818:Animals; D002417:Cattle; D004269:DNA, Bacterial; D005260:Female; D016680:Genome, Bacterial / Q000235:genetics*; D005838:Genotype; D006801:Humans; D007558:Italy; D008414:Mastitis, Bovine / Q000382:microbiology; D008892:Milk / Q000382:microbiology; D015995:Prevalence; D012329:RNA, Bacterial; D017422:Sequence Analysis, DNA / Q000662:veterinary; D013203:Staphylococcal Infections / Q000382:microbiology / Q000662:veterinary*; D013211:Staphylococcus aureus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D059467:Transcriptome / Q000235:genetics*; D014774:Virulence / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D012329:RNA, Bacterial
keywords: Genome; Mastitis; Next generation sequencing; Staphylococcus aureus; Transcriptome; Virulence