Dynamics of bovine intramammary infections due to coagulase-negative staphylococci on four farms

Abstract

The objectives of this study were to compare the impact of different coagulase-negative species (CNS) on udder health measured in terms of individual quarter milk somatic cell count (SCC) and duration of intramammary infection, and to get some insight into most likely routes of infection for different CNS species. This longitudinal observational study was performed on four farms that were sampled at 4-week intervals for a total of 12 visits each. Quarters infected with CNS were followed through time with milk samples being submitted for bacteriological culture and SCC determination. PCR amplification of the internal transcribed spacer region and sequencing of the sodA and rpoB genes were used for species allocation. Pulsed-field gel electrophoresis (PFGE) was performed to assess strain identity. The percentage of quarters affected per farm varied between 6 and 35%, with the most frequently isolated CNS species being Staphylococcus epidermidis, followed by Staph. simulans, Staph. chromogenes and Staph. haemolyticus. It was possible to follow 111 intramammary infections due to CNS through time. Duration of infection had a mean of 188 d and was not significantly different between CNS species. Geometric mean quarter SCC overall was 132 000 cells/ml and was also not significantly different between CNS species. Despite the possibility of a different epidemiology of infection, the impact in terms of udder health seems to be similar for different CNS species.

Species distribution and in vitro antimicrobial susceptibility of coagulase-negative staphylococci isolated from bovine mastitic milk

“…The most common CoNS species in our data, S. simulans , S. epidermidis , S. chromogenes , and S. haemolyticus, belong to the CoNS species reported most frequently in numerous studies on bovine intramammary infection (IMI) or mastitis. Staphylococcus chromogenes has been isolated most commonly in almost all studies [ 11 – 13 , 25 – 29 ]. It is much more common in primiparous than multiparous cows [ 11 , 28 , 30 ], with peak occurrence around the first calving [ 4 ].…”

“…It is much more common in primiparous than multiparous cows [ 11 , 28 , 30 ], with peak occurrence around the first calving [ 4 ]. Staphylococcus chromogenes seems to be present in all herds [ 26 – 29 ] and has been frequently isolated not only from milk but also from bovine teat skin and orifice and from other body sites of heifers and cows [ 20 , 31 ]. Staphylococcus simulans and S. epidermidis are common causes of IMI in some herds but not found or only occasionally found in some other herds [ 26 , 27 , 29 , 30 , 32 ].…”

“…Staphylococcus chromogenes seems to be present in all herds [ 26 – 29 ] and has been frequently isolated not only from milk but also from bovine teat skin and orifice and from other body sites of heifers and cows [ 20 , 31 ]. Staphylococcus simulans and S. epidermidis are common causes of IMI in some herds but not found or only occasionally found in some other herds [ 26 , 27 , 29 , 30 , 32 ]. Both S. epidermidis and S. simulans are reported to be more common in IMIs of multiparous than primiparous cows [ 11 , 28 , 30 ].…”

“…Staphylococcus xylosus is commonly reported in Dutch and Belgian studies [ 13 , 26 , 27 ] but is rare in Finland, Norway and Sweden [ 6 , 11 , 28 ]. Staphylococcus haemolyticus is a fairly common finding in many studies [ 11 , 13 , 26 – 29 ]. The reasons for variable proportions of CoNS species isolated from dairy cattle in different countries and individual herds are not fully elucidated but are likely related to different environmental conditions and herd management [ 10 , 31 ].…”

Comparative genome analysis of 24 bovine-associatedStaphylococcusisolates with special focus on the putative virulence genes

“…Several studies isolated it from teat skin and apex and other parts of heifers and cows ( De Vliegher et al, 2003 ; Taponen, Björkroth & Pyörälä, 2008 ). It seems to be present in all herds ( Piessens et al, 2011 ; Supré et al, 2011 ; Mørk et al, 2012 ; Bexiga et al, 2014 ) and is much more common in primiparous than multiparous cows ( Taponen et al, 2006 ; Thorberg et al, 2009 ; Mørk et al, 2012 ).…”