Journal of Mammary Gland Biology and Neoplasia

, Volume 16, Issue 4, pp 373–382

Methicillin Resistant S. aureus in Human and Bovine Mastitis


DOI: 10.1007/s10911-011-9237-x

Cite this article as:
Holmes, M.A. & Zadoks, R.N. J Mammary Gland Biol Neoplasia (2011) 16: 373. doi:10.1007/s10911-011-9237-x


Staphylococcus aureus is a ubiquitous organism that causes a variety of diseases including mastitis in cattle and humans. High-level resistance of S. aureus to β-lactams conferred by a mecA gene encoding a modified penicillin binding protein (PBP2a) was first observed in the early 1960’s. These methicillin resistant S. aureus (MRSA) have been responsible for both hospital acquired infections (HA-MRSA) and, more recently, community acquired MRSA (CA-MRSA). A small number of human MRSA mastitis cases and outbreaks in maternity or neonatal units have been reported which are generally the result of CA-MRSA. The establishment of the sequence type 398 (ST398) in farm animals, primarily pigs, in the early 2000’s has provided a reservoir of infection for humans and dairy cattle, particularly in continental Europe, described as livestock-associated MRSA (LA-MRSA). Prior to the emergence of ST398 there were sporadic reports of MRSA in bovine milk and cases of mastitis, often caused by strains from human associated lineages. Subsequently, there have been several reports describing bovine udder infections caused by ST-398 MRSA. Recently, another group of LA-MRSA strains was discovered in humans and dairy cattle in Europe. This group carries a divergent mecA gene and includes a number of S. aureus lineages (CC130, ST425, and CC1943) that were hitherto thought to be bovine-specific but are now also found as carriage or clinical isolates in humans. The emergence of MRSA in dairy cattle may be associated with contact with other host species, as in the case of ST398, or with the exchange of genetic material between S. aureus and coagulase negative Staphylococcus species, which are the most common species associated with bovine intramammary infections and commonly carry antimicrobial resistance determinants.


Bovine Mastitis MRSA Staphylococcus aureus 



penicillin binding protein


methicillin resistant S. aureus


hospital acquired MRSA


community acquired MRSA


sequence type


livestock associated MRSA


clonal complex


skin and soft tissue infections


staphylococcal cassette chromosome


Panton-Valentin leukocidin


methicillin resistant coagulase negative staphylococci


pulsed-field gel electrophoresis


multi-locus sequence typing


variable number tandem repeat


methicillin susceptible S. aureus


random amplified polymorphic DNA polymerase chain reaction


methicillin resistant S. epidermidis

Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  1. 1.Department of Veterinary MedicineUniversity of CambridgeCambridgeUK
  2. 2.Moredun Research Institute, Bush LoanPenicuikUK
  3. 3.University of Edinburgh Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary CentreRoslinUK

Personalised recommendations