Coagulase-negative staphylococci as an evolving mastitis causing organism in cows: A review

Abstract

The present review attempts to address the emergence of a fast-growing mastitis causing pathogen – coagulase-negative staphylococci (CNS) – and its multi-facet roles in dairy farms. CNS is divided into numerous species, but only a few succeed in bovine mastitis. The two predominant CNS species causing mastitis are Staphylococcus chromogenes and Staphylococcus simulans. These two mostly known CNS affects dairy cows at varied parities and at different lactation stages. CNS have been judged to be the most common bovine mastitis isolate in several countries of the world. However, CNS may not likely be as pathogenic as the other primary mastitis pathogens such as Staphylococcus aureus and its infection mostly remains subclinical. Conversely, CNS is capable of triggering persistent infections among dairy herds, resulting in reduced milk quality and high milk somatic cell count (SCC). One negative impact of CNS infection in dairy herds is that it can destroy cow udder tissue, hereby leading to a drop in milk production of dairy cows. CNS mastitis has a high cure rate when treated with anti-biotics as their infection in cows are not known to be a therapeutic problem. Judging from several literatures, it cannot be said whether CNS species act as an ecological or contagious pathogens. Regulator procedures, including pre- and post-milking teat disinfection, may reduce contagious mastitis pathogens of CNS infections in the dairy herd. Phenotypic methods for identification of CNS are not adequately dependable, and molecular techniques of identification may be better substitute for identification. Dairy farmers may benefit greatly from more empirical research on the epidemiology of CNS mastitis and more reliable methods for species identification.

Genome-Wide DNA Methylation and Transcriptome Integration Associates DNA Methylation Changes with Bovine Subclinical Mastitis Caused by Staphylococcus chromogenes

“…Mastitis is caused by a plethora of pathogens, including Staphylococcus chromogenes (SC). Staphylococcus chromogenes is one of the most predominant species of coagulase-negative staphylococci (CNS) and is considered an emerging mastitis pathogen of dairy cows in many countries [ 1 , 2 ]. It is also the most predominant CNS on Canadian dairy farms [ 3 , 4 , 5 ].…”

Exploring the distinct immunological reactions of bovine neutrophils towards major and minor pathogens responsible for mastitis

“…Certain NASM strains (e.g. S. chromogenes ) have demonstrated the ability to suppress major mastitis-causing bacteria through the secretion of antimicrobial peptides, specifically bacteriocin [ 7 , 44 ]. Bacterial activation prompts neutrophils to release antimicrobial peptides for mastitis-causing bacteria elimination.…”

“…They have been isolated from various cows’ anatomical sites and the dairy environment [ 2 , 4 , 5 ]. Although previously considered insignificant pathogens, NASM, for example, S. chromogenes, S. epidermidis , S. simulans , S. xylosus , S. haemolyticus , and Mammaliicoccus fleurettii , may pose a severe threat to the health of bovine udders [ 2 , 3 , 6 , 7 ]. NASM can potentially cause persistent IMIs [ 8–10 ], resulting in increased somatic cell count (SCC) and reduced milk production [ 6 , 7 , 10 ]; however, the impact of NASM on udder health is still a topic of discussion.…”

“…Although previously considered insignificant pathogens, NASM, for example, S. chromogenes, S. epidermidis , S. simulans , S. xylosus , S. haemolyticus , and Mammaliicoccus fleurettii , may pose a severe threat to the health of bovine udders [ 2 , 3 , 6 , 7 ]. NASM can potentially cause persistent IMIs [ 8–10 ], resulting in increased somatic cell count (SCC) and reduced milk production [ 6 , 7 , 10 ]; however, the impact of NASM on udder health is still a topic of discussion. The presence of NASM has played a role in the suppression of other Staphylococci, including the biofilm dispersion and regulation of quorum sensing [ 5 , 11 ].…”

An Interconnection between Elevated SCC Levels in Milk around the First Artificial Insemination and Pregnancy Rate in Dairy Cows

“…In our study, the cows recorded with less than 150,000 cells/ml milk before and after FAI were designed uninfected (category 1 control). This cut-off point is important because IMI with skin flora opportunists as CNS, have been found that induce light SCC levels in the milk of affected cows [4] [16] [17].…”