TY - JOUR
T1 - Risk factors associated with increased bovine leukemia virus proviral load in infected cattle in Japan from 2012 to 2014
AU - Ohno, Ayumu
AU - Takeshima, Shin nosuke
AU - Matsumoto, Yuki
AU - Aida, Yoko
N1 - Funding Information:
This work was supported by a grant from the Program for the Promotion of Basic and Applied Research for Innovations in Bio-oriented Industry, by a grant from Integration Research for Agriculture and Interdisciplinary Fields in Japan, and by the Strategic Improvement project of the national Surveillance and Diagnosis system for Animal (SISDA).
Publisher Copyright:
© 2015 Elsevier B.V..
PY - 2015/12/2
Y1 - 2015/12/2
N2 - Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis, a malignant B cell lymphoma. BLV has spread worldwide and causes serious problems. After infection, the BLV genome is integrated into the host DNA and can be amplified during periods of latency. We previously designed degenerate primers using the Coordination of Common Motifs (CoCoMo) algorithm to establish a new quantitative real-time PCR method (BLV-CoCoMo-qPCR-2) of measuring the proviral load of both known and novel BLV variants. Here, we aimed to examine the correlation between proviral load and risk factors for BLV infection, such as breeding systems, parousity, and colostrum feeding. Blood and serum samples were collected from 83 BLV-positive farms in 22 prefectures of Japan, and the BLV proviral load and anti-BLV antibody levels were measured. BLV was detected in 73.3% (1039/1,417) of cattle by BLV-CoCoMo-qPCR-2 and the provirus was detected in 93 of 1039 antibody-negative samples. The results showed that the proviral load increased with progression of lymphocytosis. Next, the risk factors associated with increasing BLV infection rate were examined along with any association with proviral load. The proviral load was higher in cattle with lymphocytosis than in healthy cattle, and higher in multiparous cows than in nulliparous cows. Finally, proviral loads were higher in contact breeding systems than in non-contact breeding systems. Taken together, these findings may help to formulate a plan for eliminating BLV from contaminated farms. This is the first nationwide study to estimate BLV proviral load in Japanese cattle.
AB - Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis, a malignant B cell lymphoma. BLV has spread worldwide and causes serious problems. After infection, the BLV genome is integrated into the host DNA and can be amplified during periods of latency. We previously designed degenerate primers using the Coordination of Common Motifs (CoCoMo) algorithm to establish a new quantitative real-time PCR method (BLV-CoCoMo-qPCR-2) of measuring the proviral load of both known and novel BLV variants. Here, we aimed to examine the correlation between proviral load and risk factors for BLV infection, such as breeding systems, parousity, and colostrum feeding. Blood and serum samples were collected from 83 BLV-positive farms in 22 prefectures of Japan, and the BLV proviral load and anti-BLV antibody levels were measured. BLV was detected in 73.3% (1039/1,417) of cattle by BLV-CoCoMo-qPCR-2 and the provirus was detected in 93 of 1039 antibody-negative samples. The results showed that the proviral load increased with progression of lymphocytosis. Next, the risk factors associated with increasing BLV infection rate were examined along with any association with proviral load. The proviral load was higher in cattle with lymphocytosis than in healthy cattle, and higher in multiparous cows than in nulliparous cows. Finally, proviral loads were higher in contact breeding systems than in non-contact breeding systems. Taken together, these findings may help to formulate a plan for eliminating BLV from contaminated farms. This is the first nationwide study to estimate BLV proviral load in Japanese cattle.
KW - BLV-CoCoMo-qPCR-2
KW - Bovine leukemia virus
KW - Dairy and beef cattle
KW - Field research
KW - Proviral load
KW - Risk factor
UR - http://www.scopus.com/inward/record.url?scp=84947761290&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84947761290&partnerID=8YFLogxK
U2 - 10.1016/j.virusres.2015.08.020
DO - 10.1016/j.virusres.2015.08.020
M3 - Article
C2 - 26321160
AN - SCOPUS:84947761290
SN - 0168-1702
VL - 210
SP - 283
EP - 290
JO - Virus Research
JF - Virus Research
ER -
