Coliform mastitis

Abstract

-Gram-negative bacteria that commonly cause bovine mastitis are classified as environmental pathogens. The point sources of coliform bacteria that cause infections include bedding materials, soil, manure and other organic matter in the environment of cows. Rates of coliform mastitis increase during climatic periods that maximize populations in the environment. The portal of entry into the mammary gland for Gram-negative bacteria is the teat canal. Once in the gland, bacteria must utilize available substrates in the mammary secretion to replicate and evade host defenses. Rates of coliform mastitis are greater during the transitional phases of the nonlactating period than during lactation. The ability to infect the non-lactating gland is directly related to the ability of bacteria to acquire iron from the mammary secretion. The primary host defense against coliform mastitis during lactation is the elimination of bacteria by neutrophils migrating into the gland in response to inflammation. Damage to the host is mediated by the release of endotoxin. The severity and duration of clinical signs associated with coliform mastitis are reduced by the use of core-antigen bacterins.

Relationship between total bacteria counts and somatic cell counts from mammary quarters infected by mastitis pathogens

“…Among the causative pathogens of subclinical cases, such as S. aureus, S. agalactiae, CNS and other streptococci (HARMON, 1994), SCC values for S. agalactiae were higher than other mastitis pathogens in both studies. The highest SCC identified among mastitis pathogens found by DJABRI et al (2002) was caused by Escherichia coli, but this pathogen usually promotes clinical mastitis due to virulence factors and consequently pathophysiological processes (HARMON, 1994;HOGAN & SMITH, 2003). The SCC geometric mean for S. aureus (587,000 cells mL -1 ) was twice as high as that found in the meta-analysis study (333,000 cells mL -1 ).…”

Molecular Epidemiology of TwoKlebsiella pneumoniaeMastitis Outbreaks on a Dairy Farm in New York State

“…Klebsiella pneumoniae is an opportunistic, environmental organism that can cause intramammary infections in dairy cows (15,32). The environment can contain a large variety of K. pneumoniae strains with pathogenic potential (26,30), and mastitis cases within a dairy herd are usually caused by many different strains (3,(23)(24)(25).…”

“…Often, recommendations for mastitis control are implemented by dairy farmers only temporarily, until the acute problem subsides and the perceived need for implementation of control measures diminishes (33,35). The incidence of Klebsiella mastitis increases under hot and humid weather conditions (15). According to the herd manager of the farm, environmental hygiene was maintained throughout the summer.…”

“…CM due to Klebsiella infection results in high milk losses and mortality of the affected cows (13). Antimicrobial therapy and vaccination have limited effects against Klebsiella CM (15,27). Hence, prevention of infections through the reduction of exposure of cows to Klebsiella has been the cornerstone of Klebsiella mastitis control on dairy farms.…”

The production and characterization of anti-bovine CD14 monoclonal antibodies

“…Bovine coliform mastitis is an inflammation of the mammary gland caused by Gram-negative bacteria, where Escherichia coli is the most common pathogen [10,19]. About 40-50% of all clinical cases of mastitis are caused by coliform bacteria [27].…”