Telmo Vidor

Herpes bovino tipo 1 (BHV 1): I. Sorologia de rebanhos com problemas reprodutivos

Serum antibodies against BHV-1 were studied, by the serum neutralization test, in cattle from Southem Brazil. Samples were collected from 2341 cattie from 112 farms that had reprodution problems. Positive results were obtained in 747 (31.9) cattie from 80 (71.31%) farms, given evidence of the expressivo virus dissemination in cattie from this region.

Green propolis phenolic compounds act as vaccine adjuvants, improving humoral and cellular responses in mice inoculated with inactivated vaccines

Adjuvants play an important role in vaccine formulations by increasing their immunogenicity. In this study, the phenolic compound-rich J fraction (JFR) of a Brazilian green propolis methanolic extract stimulated cellular and humoral immune responses when co-administered with an inactivated vaccine against swine herpesvirus type 1 (SuHV-1). When compared to control vaccines that used aluminium hydroxide as an adjuvant, the use of 10 mg/dose of JFR significantly increased (p < 0.05) neutralizing antibody titres against SuHV-1, as well as the percentage of protected animals following SuHV-1 challenge (p < 0.01). Furthermore, addition of phenolic compounds potentiated the performance of the control vaccine, leading to increased cellular and humoral immune responses and enhanced protection of animals after SuHV-1 challenge (p < 0.05). Prenylated compounds such as Artepillin C that are found in large quantities in JFR are likely to be the substances that are responsible for the adjuvant activity.

Cloning and expression of a truncated form of envelope glycoprotein D of Bovine herpesvirus type 5 in methylotrophic yeast Pichia pastoris.

Meningoencephalitis caused by Bovine herpesvirus type 5 (BoHV-5) is responsible for heavy economic losses in the cattle industry. As in other Alphaherpesviruses, the envelope glycoprotein IV (gD), which mediates penetration into host cells, is one of the major candidate antigens for a recombinant vaccine, since it induces a strong and persistent immune response. The DNA coding for a truncated form of BoHV-5 gD (tgD) has been cloned into the Pichia pastoris expression vector pPICZalphaB to allow protein secretion into the medium. After induction with methanol, a approximately 55kDa protein was obtained. Enzyme deglycosylation with Endo H showed a smaller size band in SDS-PGAE, with approximately 50kDa, suggesting that tgD has N-linked oligosaccharides and that it is not hyperglycosylated. The approximately 55kDa protein was recognized by several polyclonal antibodies, including polyclonal antibody anti-tgD and polyclonal antibodies of different animal species immunized with BoHV-5 and BoHV-1. This is the first report of BoHV-5 gD expression in yeast. It was shown that the recombinant truncated form of BoHV-5 gD has antigenic and immunogenic properties similar to the native BoHV-5 gD. Expression of tgD as a secreted protein allows simple and inexpensive purification methods that can be used for further studies to evaluate its immunogenicity in cattle.

Imunogenicidade do herpesvírus bovino tipo 5 (BHV-5) em vacinas inativadas de diferentes formulações

Four inactivated vaccines formulated with a bovine herpesvirus tipe 5 (BHV-5) strain isolated from an outbreak of bovine meningoencephalitis in Rio Grande do Sul, Brazil, were administred in forty cattle as to evaluate its immunogenicity. The vaccines A and B used mineral oil and vaccines C and D used aluminum hydroxide (Al2(OH)3) as adjuvant. The titer of the viral suspension used in all vaccines was 107.50 TCID50 / 25 ml. Immunostin®, a Mycobacterium derived immunostimulant, was added to vaccines B and D. After receiving three doses of vaccines, at 30 days intervals, only the animals of the groups A (90%) and B (100%) developed significant antibody titers. The responses to these vaccines were adjusted to linear regression, showing that the antiboby titers increased progressively with the number of immunizations. The use of Immunostin® enhanced the immunogenicity of the vaccine with aluminum hidroxide but was ineffective when associated with oil adjuvants. It was concluded that inactivated BHV-5 vaccines prepared with high titer viral suspensions and oil adjuvants induce adequate levels of antibodies in a high proportion of the vaccinees after the third dose.

Peste suína clássica: ação térmica da amostra chinesa Porto Alegre (CPA) em coelhos

Rectal temperatures of normal rabbits inoculated with different dilutions of a vaccine prepared with Chinese-Porto Alegre (CPA) strain of classical swine fever virus, were evaluated under 3 different environmental temperatures. Temperatures of normal un-vaccinated rabbits increased significantly when environmental temperature increased (P<0.001). At environmental temperatures of 12.82 ± 1.29°C, 20.65 ± 1.79°C, and 28.24 ± 2.09°C me mean rectal temperatures were 39.53°C, 39.65°C and 39.92°C, respectively. Temperatures of me vaccinated rabbits also increased significantly when environmental temperature increased (P<0.001), but did not vary with different vaccine dilutions. At environmental temperatures of 12.82 ± 1.29°C, 20.65 ±1.79°C and 28.24 ± 2.09°C, the mean higher rectal temperature were 41.17°C, 41.24°C and 41.47°C, respectively. Within a 95% confidence interval was determined that, under the 3 environmental temperatures, the rectal temperatures equal to 40.60°C, 40.67°C and 40.90°C or higher, indicated a thermal reaction to the vaccine. In vaccinated rabbits, the mean thermic rise was of 1.59°C and there were no significant differences at different environmental temperatures or virus dilutions. Within a 95% confidence interval was determined that a rise of 1.06°C or higher indicated a specific reaction to the vaccine. The rise in temperature started 24 hours after the inoculation. This time was delayed when virus dilutions decreased (P<0.001), but did not vary with different environmental temperatures. The sensitivity and specificity of the thermic reaction was evaluated by the challenge test. By regression analysis was concluded that a temperature of 40.6°C, associated with a rise in at least 1.06°C, could be considered a specific reaction of the rabbits to the CPA strain.

DOENÇA DE AUJESZKY: PROTEÇÃO CONFERIDA POR TRÊS VACINAS INATIVADAS

SUMMARY The efficacy of three different formulations of vaccines against Aujeszkys disease was tested. Vacine I was formulated with antigen in oil, simple emulsion; vaccine II in oil, with a coadjuvam of cell immunity; vaccine III with the antigen plus DEAE-dextran (DEAE-d) as the adjuvant. Efficacy tests were conducted in 48 piglets, Landrace and Large White, divided in four groups of 12 animais. Each vaccine was applied in one group and another served as the control group. The piglets received two doses of 1ml of the vaccines, intramuscular, with 15 days interval. Twenty-one days after the second shot, the piglets were challenged with crescent doses of the virus, log 10/ml (6.25, 7.25. 8.25 for the vaccinated and 4.25, 5.25, 6.25 for the controls) and four animais per dilution. The three vaccines conferred protection against the different concentrations of virus utilized: vaccine I protected 96.1%; vaccine II 90.9% and vaccine III protected 83.3%. The differences were statistically analyzed and not significant (p<0.05). The animais in the control group presented the clinical symptons of Aujeszkys disease although they had the smallest dose in the challenge test. There were also four tests conducted with rabbits and none of the vaccines conferred protection to them.