Serum antibody responses of foals to virulence-associated 15- to 17-kilodalton antigens of Rhodococcus equi.
Humoral immune responses in 16 foals to virulence-associated 15- to 17-kDa antigens of Rhodococcus equi were studied during the first fourteen weeks of life on two horse-breeding farms with a persistent incidence of R. equi infection. Serum antibody levels specific for 15- to 17-kDa antigens were measured by enzyme-linked immunosorbent assay and Western immunoblotting. Immunoglobulin G (IgG) antibodies specific to 15- to 17-kDa antigens were detected by all the foals. R. equi was found in the feces of foals during week 1 of life, and the number of fecal R. equi rapidly increased to the highest level. Virulent R. equi were isolated from the feces of the foals at a high frequency and from their environmental soil on the farms. Evidence that serum antibody response to 15- to 17-kDa antigens of virulent R. equi occurred naturally in every foal in correlation with the quantitative changes of fecal R. equi during the first 1 to 3 months of life suggests that intestinal virulent R. equi might be the most important source of antigenic stimulation in foals from contaminated farms.
Department of Animal Hygiene, School of Veterinary Medicine and Animal Sciences, Kitasato University, Aomori, Japan. takai@vmas.kitasato-u.ac.jp
S
S
Tákai
D
D
Hidaka
M
M
Fujii
Y
Y
Shindoh
T
T
Murata
S
S
Nakanishi
Y
Y
Sasaki
S
S
Tsubaki
M
M
Kamada
D000193:Actinomycetales Infections / Q000453:epidemiology / Q000276:immunology / Q000662:veterinary*; D000375:Aging / Q000276:immunology; D000818:Animals; D000831:Animals, Newborn; D000914:Antibodies, Viral / Q000097:blood*; D000917:Antibody Formation; D000956:Antigens, Viral / Q000276:immunology*; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000821:virology; D005260:Female; D006734:Horse Diseases; D006736:Horses; D015994:Incidence; D016929:Rhodococcus equi / Q000276:immunology / Q000472:pathogenicity; D012988:Soil Microbiology; D014774:Virulence
D000914:Antibodies, Viral; D000956:Antigens, Viral