Specificity and sensitivity of an indirect fluorescent antibody test to detect antibodies against bovine viral diarrhea virus.

Since being reported in 1979 and 2006, indirect fluorescent antibody (IFA) tests have not been reported to detect bovine viral diarrhea virus (BVDV) antibodies to our knowledge. Thus, we re-evaluated the efficacy and usefulness of IFA tests for BVDV serology. We tested 4 combinations of 2 antibody conjugates (fluorescein isothiocyanate [FITC]-conjugated rabbit IgG anti-bovine IgG; rabbit IgG F(ab')2 fragment anti-bovine IgG [F(ab')2 FITC-IgG]) and 2 washing solutions (PBS; carbonate-bicarbonate-buffered saline [CBBS]) to evaluate the specificity of an IFA test for BVDV. We compared the sensitivity of the optimal combination with virus neutralization (VN) tests and an ELISA, and compared IFA with VN titers against different genotype (subgenotype) strains. For the F(ab')2 FITC-IgG/CBBS combination, only 1 of the 156 (0.6%) 4-fold diluted cattle sera resulted in a nonspecific reaction; other combinations led to a much higher incidence (22.9-37.2%). For the F(ab')2 FITC-IgG/CBBS combination, IFA detection rates were identical (36 of 59) for BVDV1 and BVDV2 genotypes, and IFA titers against them were strongly correlated (r = 0.99). The antibody-detection rates of the IFA tests were almost identical to those of VN tests and the ELISA (κ: 0.96 and 0.89, respectively). The IFA titers against 4 strains (BVDV1a, BVDV1j, BVDV2a, and an unidentified strain) were similar, 1,024 to ≥4,096, although the VN titers were different. Thus, our IFA tests were specific and sensitive, and more useful than VN tests given that the IFA tests could evaluate the immune status of cattle using a representative strain, regardless of genotype (subgenotype).

Effects of a mixture of medetomidine, midazolam and butorphanol on anesthesia and blood biochemistry and the antagonizing action of atipamezole in hamsters.

Syrian golden hamsters (Mesocricetus auratus) are useful laboratory rodents for studying human infectious diseases, metabolic diseases and cancer. In other rodents, such as mice and rats, a mixture of medetomidine, midazolam and butorphanol functions as a useful anesthetic, although it alters some blood biochemical parameters. In this study, we examined the effects of this mixture on anesthesia and blood biochemical parameters, and the action of atipamezole, a medetomidine antagonist, in hamsters. Intramuscular injection of a mixture of medetomidine, midazolam and butorphanol at doses of 0.15, 2.0 and 2.5 mg/kg, respectively, had a short induction time (within 5 min) and produced an anesthetic duration of approximately 100 min in hamsters. We also demonstrated that 0.15 mg/kg of atipamezole, corresponding to the same dose as medetomidine, made hamsters recover quickly from anesthesia. The anesthetic agent markedly altered metabolic parameters, such as plasma glucose and insulin; however, 0.15 mg/kg of atipamezole returned these levels to normal range within approximately 10 min after the injection. The anesthetic also slightly altered mineral levels, such as plasma inorganic phosphorus, calcium and sodium; the latter two were also improved by atipamezole. Our results indicated that the mixture of medetomidine, midazolam, and butorphanol at doses of 0.15, 2.0 and 2.5 mg/kg, respectively, functioned as an effective anesthetic, and atipamezole was useful for antagonizing both anesthesia and biochemical alteration in hamsters.