The role of bacterial pathogens in coliform mastitis in sows

Even in modern piglet production, mastitis and lactation failure in sows represent a considerable health problem post partum, affecting in its consequences both the sow and her piglets. Known as a multifactorial syndrome, Mastitis-Metritis-Agalactia (MMA) has been topic of several studies investigating possible influencing factors at farm and sow level in the recent past. However, there is a lack of current investigations on the causative pathogens, especially with advanced laboratory methods and with an adequate control group of healthy animals. Therefore, 1026 milk samples from coliform mastitis (CM)-affected, and 972 samples from healthy sows on six farms were examined bacteriologically in this study. The spectrum of isolated bacteria did not differ significantly between diseased and healthy animals for most species, with Escherichia coli as predominant species with 70.4% positive samples from diseased, and 78.0% positive samples from healthy animals. Furthermore, other Enterobacteriaceae, Staphylococcaceae, Streptococcaceae and Enterococcaceae were isolated both from CM-affected and non-affected animals.The similar bacteria distribution underlines the multifactorial pathogenesis of CM: Only with further adverse--endogen or exogen--factors being present, ubiquitous bacteria from the sow's environment can contribute to the development of clinical signs of infection.