Coinfection of a Cow with Bovine Leukemia Virus and Mycobacterium Bovis

Abstract

Abstract. Bovine leukosis associated with infection with the delta retrovirus Bovine leukemia virus (BLV) is endemic in many cattle herds in the United States. Infection has been associated with immunosuppression and decreased productivity. Cases of tuberculosis in cows due to infection with Mycobacterium bovis reemerged in Michigan in 1998, and despite intensive eradication attempts, new cases of bovine tuberculosis are sporadically identified. The present report details a coinfection with BLV and M. bovis in a Holstein cow from Michigan that presented as part of a bovine tuberculosis screening program. Peripheral and visceral lymph nodes of this animal were markedly enlarged, homogeneously pale white, and bulged on the cut surface. The submandibular, mesenteric, and caudal mediastinal lymph nodes contained multifocal to coalescing caseogranulomas that ranged from 1 to 5 cm in diameter. Histologically, dense sheets of monomorphic populations of neoplastic lymphocytes obliterated the normal architecture of all lymph nodes. Caseogranulomas were characterized by central pools of amorphous degenerate eosinophilic and occasionally mineralized granular debris surrounded by thick rims of epithelioid macrophages, occasional Langhan's type giant cells, and fibrosis. Polymerase chain reaction assay was positive for BLV. Cultures of affected lymph nodes yielded growth of M. bovis.

Development of a preliminary diagnostic measure for bovine leukosis in dairy cows using peripheral white blood cell and lymphocyte counts

“…With respect to the effect of bovine leukosis on other infectious diseases, there have been reports on an incidence of coinfection with Mycobacterium bovis and BLV in a cow [ 5 ] and of impaired responses to E. coli bacterin in BLV-positive animals [ 4 ], suggesting a possible association between BLV infection and immunosuppression.…”

Drying Drop Technology as a Possible Tool for Detection Leukemia and Tuberculosis in Cattle

“…It is also unsuitable for milk samples (except first colostrums) because of lack of specificity and sensitivity [50]. It is known also that a coinfection with BLV and BTub in a Holstein cow is endemic in many cattle herds [51]. We tested not only serum, but blood and milk from BLV-infected animals, using AGID as a reference test, and got highly significant differences with control group.…”

Intracellular Reactive Oxygen Species Production by Polymorphonuclear Leukocytes in Bovine Leukemia Virus-Infected Dairy Cows

“…For instance, HTLV-infected patients have a pronounced immunodeficiency that is associated with frequent opportunistic infections by various pathogens [4,16,29], a situation that has also been described in BLVinfected animals [20,23,26,28,30]. Indeed, BLV has been used as a model to study HTLV-1 pathogenesis [8,9].…”

“…This phenomenon predisposes the animal to different coinfections or superinfections and increases the severity of the infections [16,29]. In fact, BLV has been associated with the coinfection of some microorganisms [20,23,26,28,30]. Therefore, the increase in the incidence of some infections associated with BLV could be the result of some alteration in the innate immune response of these animals.…”