Phagocytic Activity, Oxygen Metabolism and Serum Amyloid a Concentration in Peripheral Blood of Mink with Subclinical Aleutian Virus Infection.

Aleutian disease (AD) is a chronic disease of mink caused by the Aleutian Mink Disease Virus (AMDV) that results in dysfunction of the immune system. The prevalence of asymptomatic AMDV infections suggests a necessity to explore their effects on the cellular mechanisms of non-specific immunity in farmed mink. The study evaluated the phagocytic activity and oxygen metabolism of peripheral blood granulocytes and monocytes in mink with chronic subclinical AMDV infection. Moreover, the intensity of inflammatory processes was assessed based on the serum amyloid A (SAA) concentration. The analyses involved 24 brown mink females aged 12−24 months. The experimental group (group I) consisted of mink with chronic subclinical AMDV infections, and the control group (group II) included healthy animals. The statistical analysis was performed using the Mann-Whitney U rank test. Phagocytic activity of granulocytes and monocytes was carried out using flow cytometry, and SAA concentration was determined with enzyme-linked immunosorbent assay (ELISA). Compared with the control group, there was a significant decrease in the phagocytic activity and oxygen metabolism of granulocytes and monocytes in the AMDV-infected mink (p < 0.05). Additionally, it was found that the mean SAA value was significantly higher in the group infected with AMDV than in the control group (p < 0.05). The obtained data indicate that monitoring the serum SAA levels in mink with asymptomatic inflammation may help assess the health of mink and detect asymptomatic inflammation caused by AMDV infection.

Breeding parameters on a mink farm infected with Aleutian mink disease virus following the use of methisoprinol.

Aleutian mink disease virus is one of the greatest threats to modern mink farming. The disease reduces fecundity and causes high mortality among kits. The aim of this study was to evaluate the effectiveness of methisoprinol in counteracting the effects of Aleutian disease, both by inhibiting replication of the virus and by mitigating the harmful effects of the disease on the fecundity and weight of infected animals. The study included 300 individuals with confirmed infection, divided according to antibody titres into three experimental groups, which received a 20% methisoprinol solution, and three control groups, which did not receive the immunostimulant. In the mink from the experimental groups, the number of copies of the genetic material of the virus in the spleens and lymph nodes was one order of magnitude lower than in the case of the control groups. Mink receiving the supplement also showed higher fecundity (on average 5.83 in the experimental groups and 4.83 in the control groups), and the weight of their offspring before slaughter was over 200 g higher. Given the lack of effective methods for immunoprophylaxis and treatment, methisoprinol supplementation can be an effective means of counteracting the effects of AMDV on persistently infected farms.

Phagocytic Activity and Oxygen Metabolism of Peripheral Blood Granulocytes from Rabbits Experimentally Infected with Trichophyton Mentagrophytes.

INTRODUCTION: Phagocytic activity and oxygen metabolism of peripheral blood granulocytes from rabbits with experimental trichophytosis were assessed by flow cytometry. MATERIAL AND METHODS: Virulent species of T. mentagrophytes var. granulosum (Tm-K) isolated from rabbits with natural trichophytosis was used for experimental infection. The phagocytic activity of granulocytes was measured in whole blood by flow cytometry using the commercial Phagotest kit. Oxidative burst was measured in whole blood by flow cytometry using the commercial Bursttest kit. RESULTS: It was found that rabbits were susceptible to infection with Trichophyton mentagrophytes under experimental conditions. The analysis of the phagocytic activity indices and oxygen metabolism of granulocytes in peripheral blood of infected rabbits showed that changes of the indices were connected with the progression and regression of the disease. A significant decrease in phagocytic activity and oxygen metabolism was observed during development of fungal lesions and it remained similar throughout the progress of the disease. The highest means of the percentage of activated and ingesting phagocytes and a significant increase in the mean fluorescence intensity (representing the number of ingested bacteria) were observed during spontaneous recovery. Therefore, the decrease or increase in the indices of phagocytic activity and oxygen metabolism of granulocytes from rabbits experimentally infected with T. mentagrophytes is somehow related to the progress of infection and suppressive activity of the fungus, whose elimination during recovery caused significant increases in investigated indices of non-specific cellular immunity. CONCLUSION: The results of the present investigation confirm that the mechanism of oxygen-dependent killing is crucial in infections caused by T. mentagrophytes.