Effect of Naturally Occurring Coagulase-Negative Staphylococci Infections on New Infections by Mastitis Pathogens in the Bovine

Abstract

Microbiological data from 1123 uninfected quarters and 216 quarters with preexisting coagulase-negative staphylococci infections were analyzed to determine the influence of infection status on subsequent new infection rate. Overall, prevalence of new infections in uninfected quarters was approximately two times that in quarters already harboring a coagulase-negative Staphylococcus infection. New infections by coagulase-negative staphylococci were greater in uninfected quarters than in quarters with preexisting coagulase-negative staphylococci infections. However, no differences were observed between uninfected and infected quarters in number of new infections by major pathogens (Staphylococcus aureus, streptococci, and coliforms). No differences were observed in uninfected or coagulase-negative Staphylococcus-infected quarters in infections with minor pathogens compared with major pathogens. The influence of individual coagulase-negative Staphylococcus species on new infections was also analyzed. However, numbers of existing infections by Staphylococcus species other than Staphylococcus chromogenes were limited. Therefore, the protective capacity of each coagulase-negative Staphylococcus species was difficult to assess. Overall, a significant restriction of bacterial invasion was observed in quarters with a preexisting infection. These results suggest that quarters harboring a coagulase-negative Staphylococcus infection suppress colonization of the mammary gland by mastitis-causing pathogens.

Prevalence of coagulase-negative staphylococci in bovine mastitis in Zimbabwe

“…For example, a study in USA showed 8.1 % coagulasenegative staphylococci associated with clinical mastitis 12 . The high isolation rate of coagulase-negative staphylococci isolates in pure culture in the present study can be attributed to the fact that the organisms have been shown to exert a protective effect for the udder against superinfection by E. coli, S. agalactiae, or S. aureus 3,8 . The observation that all the coagulasenegative staphylococci isolates were sensitive to erythromycin is consistent with the observation in a study carried out in the USA 12 .…”

Coagulase-negative staphylococci (CNS) as an aetiological factor of mastitis in cows

“…Several years after the publication of these results, Watts and Owens (1989) reported the highest proportion of S. hyicus in subclinical mastitis in cows in the United States. The study conducted at the Kentucky University by Matthews et al in 1991 In the present study, four CNS species isolated from the milk of cows with clinical mastitis included S. xylosus, S. chromogenes, S. haemolyticus and S. sciuri. In clinical mastitis cases, S. xylosus was most commonly isolated while in subclinical mastitis cases -S. chromogenes.…”

Invited review: Effect, persistence, and virulence of coagulase-negative Staphylococcus species associated with ruminant udder health

“…Coagulase-negative staphylococci have not only been reported to have a negative effect on udder health; the possibility that CNS IMI or even teat apex colonization by CNS has a positive effect on udder health is an intriguing idea that has been around for a long time (Rainard and Poutrel, 1988;Matthews et al, 1991), yet still needs further exploration. Indeed, among the most important conclusions of a recent meta-analysis of existing literature by Reyher et al (2012b) is that challenge studies [i.e., experimental studies where the udder is challenged with (a) major pathogen(s)] show strong and significant protective effects of preexisting IMI by minor pathogens.…”