Prevalence and cross-immunity of Eimeria species on Korean chicken farms.
Epidemiology of Eimeria species in poultry flocks is important to increase the effectiveness of vaccinations and prophylactic strategies on chicken farms. In this study, fecal samples from 356 chicken farms were collected randomly and examined for the prevalence of Eimeria species. Through microscopic examination, it was determined that 78.7% of the tested farms were positive in Eimeria-infection. Seven Eimeria species were detected in all the positive farms by PCR amplification of the internal transcribed spacer 1 (ITS-1) region with species-specific primers. E. acervulina and E. tenella were the most prevalent, followed by E. brunetti and E. praecox (87.5, 62.5, 59.3, and 37.5% of the farms, respectively). Each of E. maxima, E. mitis, and E. necatrix was identified in 31.3% of the farms. Individual positive fecal samples contained multiple Eimeria species (mean=3.4). Since E. maxima is known to generate antigenic variants, cross-immunity was investigated for four isolates of E. maxima from the poultry farms in different regions of Korea. The extent of cross-protection varied from 54.3 to 100% against the heterologous isolates. The results obtained from this large-scale survey will be a useful reference for controlling coccidiosis in the poultry industry.
Lee
Byung H
BH
College of Veterinary Medicine & Research Institute of Life Science, Gyeongsang National University, Jinju, Korea.
Kim
Woo H
WH
Jeong
Jipseol
J
Yoo
Jeongmi
J
Kwon
Yong-Kuk
YK
Jung
Byeong Y
BY
Kwon
Jun H
JH
Lillehoj
Hyun S
HS
Min
Wongi
W
D000818:Animals; D002645:Chickens / Q000276:immunology; D003048:Coccidiosis / Q000453:epidemiology / Q000276:immunology / Q000662:veterinary*; D017931:DNA Primers; D016054:DNA, Protozoan / Q000235:genetics / Q000302:isolation & purification; D004539:Eimeria / Q000235:genetics / Q000276:immunology*; D005243:Feces / Q000469:parasitology; D005260:Female; D007723:Korea / Q000453:epidemiology; D008297:Male; D033661:Oocysts / Q000469:parasitology; D016133:Polymerase Chain Reaction; D011201:Poultry Diseases / Q000453:epidemiology / Q000276:immunology / Q000469:parasitology*; D016052:Protozoan Vaccines / Q000627:therapeutic use*
D017931:DNA Primers; D016054:DNA, Protozoan; D016052:Protozoan Vaccines