Serological and histological evaluation of species-specific immunocontraceptive vaccine antigens based on zona pellucida 3 in the small Indian mongoose (Herpestes auropunctatus).

The small Indian mongoose (Herpestes auropunctatus) was introduced to Japanese islands and has impacted on the island's biodiversity. Population control has been attempted through capturing but its efficiency has rapidly declined. Therefore, new additional control methods are required. Our focus has been on the immunocontraceptive vaccines, which act in an especially species-specific manner. The amino-acid sequence of the mongoose ovum zona pellucida protein 3 (ZP3) was decoded and two types of synthetic peptides (A and B) were produced. In this study, these peptides were administered to mongooses (each n=3) and the sera were collected to verify immunogenicity using ELISA and IHC. Treated mongoose sera showed an increasing of antibody titer according to immunizations and the antigen-antibody reactions against the endogenous mongoose ZP. In addition, IHC revealed that immune sera absorbed with each peptide showed a marked reduction in reactivity, which indicated the specificity of induced antibodies. These reactions were marked in peptide A treated mongoose sera, and the antibody titer of one of them lasted for at least 21 weeks. These results indicated that peptide A was a potential antigen, inducing autoantibody generation. Moreover, immunized rabbit antibodies recognized mongoose ZP species-specifically. However, the induction of robust immune memory was not observed. Also, the actual sterility effects of peptides remain unknown, it should be verified as a next step. In any case, this study verified synthetic peptides we developed are useful as the antigen candidates for immunocontraception of mongooses.

Safety studies with the oral rabies virus vaccine strain SPBN GASGAS in the small Indian mongoose (Herpestes auropunctatus).

BACKGROUND: Oral vaccination of the small Indian mongoose against rabies has been suggested as a potential tool to eliminate mongoose-mediated rabies on several Caribbean islands. A recently developed oral rabies virus vaccine strain, SPBN GASGAS, has already been shown to be efficacious in this reservoir species. Since, all available oral rabies vaccines are based on replication-competent viruses and vaccine baits are distributed unsupervised in the environment, enhanced safety standards for such vaccine types are required. RESULTS: The results of safety studies, including overdose, repeated doses, dissemination and different routes of administration, in the target species are presented. It was shown that the construct was apathogenic, irrespective of dose and route of administration. Even when it was inoculated directly in the brain, it did not induce rabies infection. Furthermore, the vaccine strain did not spread within the target species after direct oral instillation beyond the site of entry. CONCLUSION: The vaccine strain SPBN GASGAS meets the safety requirements for live rabies virus vaccines in this target species, the small Indian mongoose.

Neutralization of hemorrhagic snake venoms by sera of Trimeresurus flavoviridis (Habu), Herpestes edwardsii (mongoose) and Dinodon semicarinatus (Akamata).

The sera of T. flavoviridis (Habu), H. edwardsii (mongoose) and D. semicarinatus (Akamata, non-venomous snake) were tested for their capacity to neutralize 28 species of hemorrhagic snake venoms in vitro. The sera of these animals neutralized a variety of hemorrhagic venoms, suggesting a common structure for a hemorrhagic factor and a similar mechanism of neutralization for the antihemorrhagic factor in the sera. The serum of T. flavoviridis neutralized the lethal toxicity of the T. flavoviridis venom but could not neutralize those of the other hemorrhagic venoms at all. The sera of H. edwardsii and D. semicarinatus did not inhibit the activity of all hemorrhagic venoms.

Mongoose rabies.

Mongooses are indigenous to Africa and Asia and have been introduced elsewhere. In Cuba, Puerto Rico, Grenada, and South Africa they are the major reservoir and vector of rabies. Elsewhere, sporadic cases of mongoose rabies are reported, but dog rabies can mask their importance. Population density probably determines the importance of the mongoose as a reservoir of rabies. In Grenada during a 4-year period, nearly 30% (and in some areas greater than 50%) of mongooses were found to have rabies serum neutralizing antibodies. The annual proportions of mongooses that were serum antibody-positive and virus-positive, respectively, were inversely related. Natural immunity in mongooses probably lasts for life. In contrast with foxes, in mongooses immunity is an important factor in the epizootiology of rabies. Inoculation of mongooses with Evelyn-Rokitnicki-Abelseth (ERA) vaccine induced a good immunologic response and augurs well for the success of vaccination in the field. The effects of wildlife vaccination on animal populations with high levels of natural immunity need to be investigated before costly campaigns are started.

Oral administration of an attenuated strain of canine adenovirus (type 2) to raccoons, foxes, skunk, and mongoose.

An attenuated strain of canine adenovirus type-2 (CAV-2) was administered orally to 2 foxes (Vulpes fulva), 6 raccoons (Procyon lotor), a skunk (Mephitis mephitis), and a mongoose (Herpestus auropunctatus). Blood was collected weekly from the animals to monitor CAV-2 virus-neutralizing antibody titers. All animals had increases in titers. Sera from 8 foxes, 30 mongooses, 52 raccoons, and 22 skunks trapped in the field had naturally occurring antibody to CAV-2.

Rabies serum neutralizing antibody in mongooses from Grenada.

During a four-year study on Grenada, 4,754 mongooses were examined, of which 100 (2.1%) were rabid. Of 1,675 mongooses tested for rabies serum neutralizing (SN) antibody, 498 (30%) were positive. During these four years (1971-74) the antibody prevalence rate increased from 20.8% to 43.2%, whereas the number of rabid mongooses decreased from 3.5% to 0.6%. Naturally acquired antibody was monitored in 20 captive mongooses for up to 35 months, and it was still circulating in 18 when monitoring ceased. The highest titre recorded was 1:1,400, and the rate of fall was greatest in mongooses with high initial titres. High titres of naturally acquired antibody suggest recent rabies activity. 14 mongooses vaccinated parenterally with 1.0 ml of attenuated ERA vaccine showed substantial increases in antibody titres; most had titres greater than 1:1,000 one month later and maintained a high titre for several months. The highest recorded was 1:34,800. The virus titres of brain material from rabid mongooses ranged from 10(1.8) to 10(4.3) and, in some cases, were only slightly lower than those of salivary gland tissue (range, 10(1) to 10(5.6).

Rabies serum neutralizing antibody in mongooses from Grenada

During a four year study on Grenada, 4,754 mongooses were examined, of which 100 (2.1 percent) were rabid. Of 1,675 mongooses tested for rabies serum neutraslizing (SN) antibody, 498 (30 percent) were positive. During these four years (1971-74) the antibody prevalence rate increased from 20.8 percent to 43.3 percent, whereas the number of rabid mongooses decreased from 3.5 percent to 0.6 percent. Naturally acquired antibody was monitored in 20 captive mongooses for up to 35 months, and it was still circulating in 18 when monitoring ceased. The highest titre recorded was 1:1,400, and the rate of fall was highest in mongooses with high initial titres. High titres of naturally occuring antibody suggest recent rabies activity. 14 mongooses vaccinated parenterally with 1.0 ml of attenuated ERA vaccine showed substantial increases in antibody titres; most had titres greater than 1:1,000 one month later and maintained a high titre for several months. The highest recorded was 1:34,800. The virus titres of brain material from rabid mongooses ranged from 10 to the power 1.8 to 10 to the power 4.3 and, in some cases, were only slightly lower than those of salivary gland tissue (range 10 to the power 1 to 10 to the power 5.6) (Summary)

Differentiating feline T and B lymphocytes by rosette formation.

The number of bone marrow-derived and thymus-dependent lymphocytes in the peripheral blood of felines was assessed. Feline bone marrow-derived lymphocytes were determined by erythrocyte antibody complement (EAC)-rosette formation and membrane immunofluorescence. A good correlation was observed between the cells forming EAC-rosettes (mean of 40.2 +/- 9.7%) and those possessing membrane immunoglobulins (mean of 45.3 +/- 4.1%). Feline thymus-dependent lymphocytes form non-immune (E)-rosettes with rodent erythrocytes (mouse, rat, guinea pig) but not with erythrocytes from humans, monkeys, dogs, mongooses, chickens, rabbits, sheep, and hamsters. An average of 32.3 +/- 992% of the peripheral blood lymphobytes of cats formed rosettes with guinea pig erythrocytes. Antibody blocking, cytotoxicity, and mix-rosette studies demonstrated that guinea pig red blood cells bind specifically to T lymphocytes. Of feline peripheral blood lymphocytes, 41.0 +/- 7.5% showed fluorescent staining with fluorescein-labeled rabbit anti-cat thymus antiserum.