@inproceedings{916113,
  abstract     = {{Introduction: Bulk milk coli count is one of the parameters of Flemish milk quality control. In surveillance of the coli count subclinical Klebsiella mastitis turns out to be an emerging problem in well-managed Flemish dairy herds. This is in contrast with various outbreak reports with high production losses or lethal outcome in other countries. Bedding materials and faeces are frequently pinpointed as potential sources of mastitic Klebsiella. This study was designed to further elucidate Klebsiella pneumoniae transfer to quarter milk with a molecular typing technique of high discriminating power.
Materials and Methods: A longitudinal study was carried out in 6 Flemish dairy herds from May 2008 until May 2009. In each herd 10 cows were randomly selected (4 cows of first, 3 cows of second and 3 cows of third or higher parity). All cows were housed in free-stalls with sawdust bedded cubicles.
Each month, coliforms were isolated from sawdust stock, sawdust bedding, faeces, and quarter milk. Isolates which tested positive for Klebsiella pneumonia by PCR were further typed to strain level by Pulsed Field Gel Electrophoresis (PFGE). Band patterns were clustered with the BioNumerics version 5.10 software (Applied Maths, Sint-Martens-Latem, Belgium).
Results: Of 73 sawdust stock and 73 sawdust bedding samples 6 and 20 contained K. pneumoniae, respectively. In faeces 121 of 566 samples contained K. pneumoniae while in the 2796 quarter milk samples only two turned out to be positive. In total 108 different K. pneumoniae strains were typed. The six isolates from sawdust stock belonged to six different strains. In sawdust bedding 18 different strains were detected (1 to 5 per herd) and in faeces 92 different strains were observed (1 to 27 per herd). The two isolates from milk were from the same herd (not from the same cow or quarter) but differed in PFGE pattern. However, the same PFGE type of one of these isolates was also present in one sawdust bedding sample of that herd. No similarity was found between strains of sawdust stock and strains of other sources. 
Discussion: Monthly sampling, bacterial isolation and typing of K. pneumoniae strains with a highly discriminating genotypic method as PFGE on cow and environmental level in 60 cows of 6 well managed dairy farms could not reveal a strong transfer pattern of K. pneumoniae towards udder quarters. The low incidence of K. pneumoniae intramammary infection in an environment where K. pneumoniae is highly prevalent, suggests that infection with K. pneumoniae can be facilitated by failure of cow defence mechanisms rather than by K. pneumoniae pathogenicity factors.}},
  author       = {{Verbist, Bert and Piessens, Veerle and Braem, Gorik and De Vliegher, Sarne}},
  booktitle    = {{DMRW, Annual meeting, Book of abstracts}},
  keywords     = {{mastitis,Klebsiella pneumoniae,cattle}},
  language     = {{eng}},
  location     = {{Wageningen, The Netherlands}},
  pages        = {{29--29}},
  publisher    = {{Wageningen University}},
  title        = {{Klebsiella pneumoniae can be highly prevalent in the environment of cows without causing mastitis}},
  year         = {{2009}},
}