Royal pastel mink respond variously to inoculation with Aleutian disease virus of low virulence

Abstract

Information was sought on the varied responses of royal pastel mink (a non-Aleutian genotype) to Aleutian disease virus of low virulence. Thus, of 20 yearling female pastel mink inoculated subcutaneously with a large amount of the Pullman strain of Aleutian disease virus, only 3 succumbed to the disease. Of the other 17 mink, 3 had neither viremia nor a rise in level of serum gamma globulin during the 24 weeks after inoculation. The other 14 mink were viremic for variable periods during the first 12 weeks. In only five mink was the viremia accompanied by elevated levels of serum gamma globulin, usually from week 8 on. Of the 16 subclinically infected mink that did not succumb to intercurrent disease and otherwise remained healthy, 9 were examined at 19 to 31 months for persisting virus. In only one mink, small amounts were detected in the mesenteric lymph node and spleen nearly 28 months after inoculation. The other seven mink that survived the infection were not protected when challenged 31 months later with a small amount of the highly virulent Utah-1 strain. Even though still poorly understood, these varied responses of the royal pastel mink to infection with Aleutian disease virus of low virulence have important pathogenetic and epidemiological implications.

The relationship between capsid protein (VP2) sequence and pathogenicity of Aleutian mink disease parvovirus (ADV): a possible role for raccoons in the transmission of ADV infections

“…The mink with the transient positive serum PCR had minimal hepatic lesions of subclinical disease typical of pastels infected with this strain of virus. These findings were concordant with previous observations on ADV-Pullman in sapphire and pastel mink (23,(41)(42)(43).…”

“…gene sequences of ADV, other portions of the ADV genome might also influence pathogenicity. For example, ADV-Pullman is pathogenic only for non-Aleutian mink (23,42,43), although its VP2 sequence is extremely similar to those of ADV-Utah and ADV-ZK8 (Fig. 2).…”

“…However, the specific virus strain as well as the age and genotype of the mink strongly influence whether this classical picture occurs after infection (23,40,42,43).…”

“…A number of different isolates of ADV have been compared in adult mink (23,38,(40)(41)(42)(43). Highly pathogenic isolates, such as ADV-Utah, the Canadian ADV-Ontario, and the Danish ADV-K, reliably cause classical AD in adult mink of both Aleutian and non-Aleutian genotypes (3,40,42).…”

“…Highly pathogenic isolates, such as ADV-Utah, the Canadian ADV-Ontario, and the Danish ADV-K, reliably cause classical AD in adult mink of both Aleutian and non-Aleutian genotypes (3,40,42). ADV-Pullman, on the other hand, induces severe disease in Aleutian mink, but its pathogenicity is greatly reduced in non-Aleutian animals (23,42,43,64). Furthermore, the cell culture-adapted ADV-G strain has a severely reduced capacity for in vivo replication and is nonpathogenic, although it replicates permissively in cell culture (19,24).…”