Sensitivity of the standardized pseudorabies virus neutralization test varies with the test strain used.

The effect of altering the strain of the test virus used in the standardized pseudorabies virus neutralization (VN) test on the sensitivity of the assay was evaluated. Comparative VN tests were performed using 4 different strains: the avirulent Bartha parental, the avirulent recombinant Bartha gIIIKa, the moderately virulent Shope (currently used for the VN test at the National Veterinary Services Laboratory, Ames, IA), and the highly virulent P2208 (Funkhauser). A radioimmunoassay and a Western immunoblotting technique were employed to verify the presence of anti-pseudorabies virus (PrV) antibodies in sera. Statistical analysis indicated that replacement of the Shope strain by the Bartha gIIIKa or the P2208 strain resulted in VN titers that were 4.23- and 2.00-fold higher, respectively. Despite these differences, specificity with regard to PrV diagnosis was unaltered. This apparent enhancement of the sensitivity of the PrV VN test would be beneficial for the serologic identification of PrV-infected animals during an eradication effort.     

Value of the antiglobulin test and indirect immunofluorescence test in the serological diagnosis of bovine brucellosis]

In investigations of 5881 sera from brucella infected herds and 8635 sera from negative herds the antiglobulin test (AgT) because of its high susceptibility was shown to be a valuable method in early diagnosis of brucellosis and clearing of non-specific LA-reactions. However, all infected animals are not detected with the AgT. Therefore it is not adaptable to use in selection controlling, also in combination with other methods. In the final steps of the eradication measures against bovine brucellosis the AgT offers a very valuable serological complementary method. The indirect fluorescence test has no diagnostical advantages in comparison with the AgT and is not recommended for practical brucellosis serology.     

Serological investigation of Corynebacterium pseudotuberculosis infection in sheep--correlation between the hemolysis inhibition test and the ELISA test

Corynebacterium pseudotuberculosis causes caseous lymphadenitis in sheep and goats. The animals may be infected without showing clinical symptoms. Several serotests have therefore been employed to detect infected animals. Shen et al (1982) performed an enzyme linked immunosorbent assay (ELISA) to detect antibodies against the organism using cell wall antigens. Maki et al (1985) found that the toxin of the bacterium was a better antigen for assessing infection in the ELISA test. They reported that the antitoxin ELISA appeared to be as sensitive as the antihemolysin inhibition test (Zaki 1968).     

Hyaluronidase test in the diagnosis of staphylococci

Using the Streptococcus equi decapsulation test, 879 strains of S. aureus, 212 strains of S. intermedius and 214 coagulase-negative staphylococci were examined for hyaluronidase production; six of the coagulase-negative staphylococci belonged to S. hyicus subsp. hyicus. Positive hyaluronidase production was recorded in all strains of S. aureus and in the strains of S. hyicus subsp. hyicus. No hyaluronidase was produced by 208 coagulase-negative staphylococci and the strains of S. intermedius. The decapsulation test is recommended as a reliable method of the differentiation of S. aureus and S. intermedius.     

Evaluation of the dermatophyte test medium RapidVet-D

The performance of the dermatophyte test medium (DTM) RapidVet-D was assessed using hair samples collected from experimentally infected guinea pigs. Three dermatophyte species were included in the study: Microsporum canis , Trichophyton mentagrophytes and Trichophyton equinum . DTM substrates were inoculated with infected hairs and scales, incubated at 18, 21, 24, 27 or 37 °C and examined daily for 15 days. The rapidity of colour change was clearly related to the incubation temperature and to the number of infected hairs deposited on the reactive substrates. With the optimum incubation temperature 27 °C, a systematic colour change could be observed only a few days post-inoculation: 3 days with M. canis infected hairs, 4 days with T. equinum and 5 days with T. mentagrophytes .