Immunization of rhesus macaques with Echinococcus multilocularis recombinant 14-3-3 antigen leads to specific antibody response.

E. multilocularis (Em) is the etiologic agent of alveolar echinococcosis (AE), a severe and potentially fatal disease, primarily affecting the liver of and occurring in aberrant intermediate hosts, e.g., humans and non-human primates. Due to increasing numbers of spontaneous cases of AE in the Old World monkey colonies of the German Primate Center, the question arose as to whether vaccination of non-human primates may represent a useful prophylactic approach. In this pilot study, the recombinant antigen Em14-3-3, which has provided a 97 % protection against E. multilocularis challenge infection in rodent models, was used for the first time to immunize rhesus macaques. In order to increase immunogenicity, the antigen was formulated with different adjuvants including Quil A®, aluminum hydroxide (alum), and muramyl dipeptide (MDP). Also, different vaccination regimens were tested. All vaccinated animals developed antigen-specific antibodies. While Quil A® induced a local adverse reaction, alum proved to be the most potent adjuvant in terms of induced antibody levels, longevity as well as tolerability. In conclusion, our pilot study demonstrated that recombinant Em14-3-3 is safe and immunogenic in rhesus monkeys. As a next step, efficacy of the vaccination remains to be explored.

Necrotizing endometritis and isolation of an alpha-toxin producing strain of Clostridium septicum in a wild sooty mangabey from Côte d'Ivoire.

Few lethal pathogens in wild-living primates have been described, and little is known about infectious diseases of the reproductive tract and their possible impact on health and reproduction. This report describes the pathology and isolation of an alpha-toxin producing strain of Clostridium septicum in a case of necrotizing endometritis in a wild sooty mangabey found dead in a tropical rainforest of West Africa.

Meeting report: Emerging respiratory viral infections and nonhuman primate case reports.

A workshop on Emerging Respiratory Viral Infections and Spontaneous Diseases in nonhuman primates was sponsored by the concurrent Annual Meetings of the American College of Veterinary Pathologists and the American Society for Veterinary Clinical Pathology, held December 1-5, 2012, in Seattle, Washington. The session had platform presentations from Drs Karen Terio, Thijs Kuiken, Guy Boivin, and Robert Palermo that focused on naturally occurring influenza, human respiratory syncytial virus, and metapneumovirus in wild and zoo-housed great apes; the molecular biology and pathology of these viral respiratory diseases in nonhuman primate (NHP) models; and the therapeutic and vaccine approaches to prevention and control of these emerging respiratory viral infections. These formal presentations were followed by presentations of 14 unique case studies of rare or newly observed spontaneous lesions in NHPs (see online files for access to digital whole-slide images corresponding to each case report at http://scanscope.com/ACVP%20Slide%20Seminars/2012/Primate%20Pathology/view.apml). The session was attended by meeting participants that included students, pathology trainees, and experienced pathologists from academia and industry with an interest in respiratory and spontaneous diseases of NHPs.

Invasive aspergillosis in a putty-nosed monkey (Cercopithecus nictitans) with adrenocortical Cushing's syndrome.

BACKGROUND: An 18-year-old captive female putty-nosed-monkey (Cercopithecus nictitans) with a history of long-term infertility and hyperglucocorticism was euthanized because of perforating thoracic trauma induced by group members and subsequent development of neurological signs. METHODS: Complete necropsy and histopathological examination of formalin-fixed tissue samples was carried out. RESULTS: The monkey showed invasive pulmonary and cerebral infection with Aspergillus fumigatus together with adrenocortical neoplasia and signs of Cushing's syndrome, such as alopecia with atrophic skin changes, evidence for diabetes mellitus and marked immunosuppression. CONCLUSIONS: Spontaneous endocrinopathies are rarely described in non-human primates. Here we report the first case of spontaneous adrenocortical hyperglucocorticism predisposing to systemic aspergillosis in a putty-nosed monkey.

Treponema infection associated with genital ulceration in wild baboons.

The authors describe genital alterations and detailed histologic findings in baboons naturally infected with Treponema pallidum. The disease causes moderate to severe genital ulcerations in a population of olive baboons (Papio hamadryas anubis) at Lake Manyara National Park in Tanzania. In a field survey in 2007, 63 individuals of all age classes, both sexes, and different grades of infection were chemically immobilized and sampled. Histology and molecular biological tests were used to detect and identify the organism responsible: a strain similar to T pallidum ssp pertenue, the cause of yaws in humans. Although treponemal infections are not a new phenomenon in nonhuman primates, the infection described here appears to be strictly associated with the anogenital region and results in tissue alterations matching those found in human syphilis infections (caused by T pallidum ssp pallidum), despite the causative pathogen's greater genetic similarity to human yaws-causing strains.

Meeting report: Spontaneous lesions and diseases in wild, captive-bred, and zoo-housed nonhuman primates and in nonhuman primate species used in drug safety studies.

The combination of loss of habitat, human population encroachment, and increased demand of select nonhuman primates for biomedical research has significantly affected populations. There remains a need for knowledge and expertise in understanding background findings as related to the age, source, strain, and disease status of nonhuman primates. In particular, for safety/biomedical studies, a broader understanding and documentation of lesions would help clarify background from drug-related findings. A workshop and a minisymposium on spontaneous lesions and diseases in nonhuman primates were sponsored by the concurrent Annual Meetings of the American College of Veterinary Pathologists and the American Society for Veterinary Clinical Pathology held December 3-4, 2011, in Nashville, Tennessee. The first session had presentations from Drs Lowenstine and Montali, pathologists with extensive experience in wild and zoo populations of nonhuman primates, which was followed by presentations of 20 unique case reports of rare or newly observed spontaneous lesions in nonhuman primates (see online files for access to digital whole-slide images corresponding to each case report at http://www.scanscope.com/ACVP%20Slide%20Seminars/2011/Primate%20Pathology/view.apml). The minisymposium was composed of 5 nonhuman-primate researchers (Drs Bradley, Cline, Sasseville, Miller, Hutto) who concentrated on background and spontaneous lesions in nonhuman primates used in drug safety studies. Cynomolgus and rhesus macaques were emphasized, with some material presented on common marmosets. Congenital, acquired, inflammatory, and neoplastic changes were highlighed with a focus on clinical, macroscopic, and histopathologic findings that could confound the interpretation of drug safety studies.

Systemic herpesvirus infection in an Azara's Night Monkey (Aotus azarae).

BACKGROUND: Intra- and inter-species transmission of Human herpesvirus type 1 were noticed. In the present study, the herpesviral infection of a 1-year-old Azara's Night Monkey (Aotus azarae) was investigated. METHODS: Immunohistochemistry and electron microscopy investigations were done. RESULTS: A fatal systemic herpesviral infection was demonstrated. CONCLUSION: The results reveal the susceptibility of Azara's Night Monkey to the Human herpesvirus type 1. Moreover, humans shedding herpes viral particles during the reactivation phase of the infection directly infect the Azara's Night Monkeys.

Rapid infection of oral mucosal-associated lymphoid tissue with simian immunodeficiency virus.

The early events during infection with an immunodeficiency virus were followed by application of pathogenic simian immunodeficiency virus atraumatically to the tonsils of macaques. Analyses by virologic assays and in situ hybridization revealed that the infection started locally in the tonsils, a mucosal-associated lymphoid organ, and quickly spread to other lymphoid tissues. At day 3, there were few infected cells, but then the number increased rapidly, reaching a high plateau between days 4 and 7. The infection was not detected in the dendritic cell-rich squamous epithelium to which the virus was applied; instead, it was primarily in CD4+ tonsillar T cells, close to the specialized antigen-transporting epithelium of the tonsillar crypts. Transport of the virus and immune-activating stimuli across this epithelium would allow mucosal lymphoid tissue to function in the atraumatic transmission of immunodeficiency viruses.

Outbreak of Streptococcus equi subsp. zooepidemicus infection in a group of rhesus monkeys (Macaca mulatta).

BACKGROUND: A severe upper respiratory tract infection occurred in a breeding group of rhesus monkeys housed together in one of six indoor/outdoor corals of the German Primate Center. The clinical signs of the disease included severe purulent conjunctivitis, rhinitis, pharyngitis, respiratory distress and lethargy. Six of 45 animals died within a few days after developing signs of infection. METHODS AND RESULTS: Histopathologic and microbiologic examinations of the dead animals were consistent with a severe fibrinopurulent bronchopneumonia. Microbiology revealed a Lancefield group C streptococcus identified as Streptococcus equi subsp. zooepidemicus as the causative agent of infection. CONCLUSIONS: The infection was passed on from animal to animal but did not spread to the other five breeding groups nearby. Extensive diagnostic testing failed to reveal the consisting presence of copathogens in individual cases. A visitor with upper respiratory disease was suspected as source of infection.

Mhc class I haplotypes associated with survival time in simian immunodeficiency virus (SIV)-infected rhesus macaques.

In both human immunodeficiency virus-infected humans and simian immunodeficiency virus (SIV)-infected macaques, genes encoded in the major histocompatibility complex (MHC) class I region are important determinants of disease progression. However, compared to the human human lymphocyte antigen complex, the macaque MHC region encodes many more class I genes. Macaques with the same immunodominant class I genes express additional Mhc genes with the potential to influence the disease course. We therefore assessed the association between of the Mhc class I haplotypes, rather than single gene variants, and survival time in SIV-infected rhesus macaques (Macaca mulatta). DNA sequence analysis and Mhc genotyping of 245 pedigreed monkeys identified 17 Mhc class I haplotypes that constitute 10 major genotypes. Among 81 vaccination-naive, SIV-infected macaques, 71 monkeys carried at least one Mhc class I haplotype encoding only MHC antigens that were incapable of inducing an effective anti-SIV cytotoxic T lymphocytes response. Study of these macaques enabled us to relate individual Mhc class I haplotypes to slow, medium and rapid disease progression. In a post hoc analysis, classification according to disease progression was found to explain at least 48% of the observed variation of survival time.

Outbreak of Tuberculosis in a Colony of Rhesus Monkeys (Macaca mulatta) after Possible Indirect Contact with a Human TB Patient.

Simian tuberculosis is one of the most important bacterial diseases of non-human primates. Outbreaks of tuberculosis have been reported in primate colonies almost as long as these animals have been used experimentally or kept in zoological gardens. Significant progress has been made in reducing the incidence of tuberculosis in captive non-human primates, but despite reasonable precautions, outbreaks continue to occur. The most relevant reason is the high incidence of tuberculosis (TB) amongst the human population, in which tuberculosis is regarded as an important re-emerging disease. Furthermore, many non-human primate species originate from countries with a high burden of human TB. Therefore, Mycobacterium tuberculosis remains a significant threat in animals imported from countries with high rates of human infection. We report an outbreak of tuberculosis among a group of rhesus monkeys (Macaca mulatta) living in a closed, long-term colony. The outbreak coincided with reactivation of a TB infection in a co-worker who never had direct access to the animal house or laboratories. Eleven of 26 rhesus monkeys developed classical chronic active tuberculosis with typical caseous granulomata of varying size within different organs. The main organ system involved was the lung, suggesting an aerosol route of infection. Such an outbreak has significant economic consequences due to animal loss, disruption of research and costs related to disease control. Precautionary measures must be improved in order to avoid TB in non-human primate colonies.

Live attenuated SIV vaccines are not effective in a postexposure vaccination model.

Live attenuated simian immunodeficiency virus (SIV) vaccines, like nef deletion mutants, have been the most effective vaccines tested in the SIV/macaque model so far. The efficacy of live attenuated SIV vaccines in therapeutic vaccination and postexposure prophylaxis has not been determined. Inoculation of macaques with a pathogenic challenge virus and an attenuated SIV vaccine at the same time mimics postexposure vaccination, whereby vaccination with the attenuated virus is performed as rapidly as possible after exposure to pathogenic SIV. In the study presented here, four rhesus macaques were coinfected with pathogenic SIV and a nearly 3000-fold excess of a nef deletion mutant of SIV. Four macaques received pathogenic SIV and an approximately 200-fold excess of a nef deletion mutant expressing interleukin 2 (IL-2). The IL-2-expressing SIV had been previously constructed to enhance the immunogenicity of live attenuated SIV vaccines. All coinfected macaques had a high viral load, and some of them developed AIDS-like symptoms and pathological alterations rapidly. In the presence of pathogenic SIV, both live attenuated SIV vaccines did not protect from disease in this postexposure vaccination model.

Cytokine gene transcription in simian immunodeficiency virus and human immunodeficiency virus-associated non-Hodgkin lymphomas.

Infection of rhesus monkeys with SIV leads to AIDS-like symptoms. Similar to human AIDS patients, some monkeys develop B cell non-Hodgkin lymphoma (NHL). We determined transcription of cytokine genes regulating the activation of B and T cells, which play a role in intratumoral immune surveillance. Therefore, we compared the transcription of the cytokine genes encoding IL-2, IL-4, IL-6, IL-10, IFN-gamma, TNF-alpha, and TGF-beta1, and the Epstein-Barr virus-encoded BCRF 1 gene, in cells from five monkey and two human tumor specimens. The immune-suppressive IL-10 and TGF-beta1 genes were predominantly transcribed in all tumor specimens analyzed. Cytokine gene transcription patterns appeared to be similar in human and animal tumor cells. The transcription patterns corresponded to their histological classification as diffuse large-cell lymphoma according to the REAL classification and as immunoblastic or centroblastic tumors according to the Kiel classification. The determination of cytokine gene transcription pattern in the NHL may improve our understanding of pathogenesis and immune surveillance in this heterogeneous group of tumors. Our data show that SIV-associated NHLs of rhesus monkeys are comparable to human HIV-1-associated EBV-positive non-Hodgkin lymphoma.

Immunohistochemical detection of simian immunodeficiency virus (SIV) in rectal mucosa of experimentally infected rhesus macaques (Macaca mulatta).

Experimental simian immunodeficiency virus (SIV) infection is the most appropriate animal model for human HIV infection. Eight male rhesus monkeys (Macaca mulatta) were intravenously or intrarectally infected with SIVmac251/MPBMC to comparatively investigate the distribution and spread of the virus within the rectum during the course of the disease. SIV-positive cells were immunohistochemically detected in rectal biopsies obtained at days 3 and 7 and week 2, 4 and 12 postinfection. SIV-expressing cells were detected for the first time at one week after experimental infection and were present in the lamina propria and lymph follicles. Numbers of positive cells per individual animal varied strongly in time, with a more rapid rise in animals with rapid progression of the disease. Differences were not observed between intravenous and intrarectal infection. Our observations support the significance of the intestinal tract as target organ in initial pathogenesis of SIV infection.

Retinal detachment in horses.

Ten horses with partial or total retinal detachment were investigated using light and electron microscopy (TEM, SEM). Several lesions were observed and compared with normal retinal morphology. Three weeks after the initial retinal detachment, hypertrophy of the pigment epithelium with transformation of the apical microvilli could be observed. The lesions were accompanied by progressive degeneration and atrophy of the sensory retina, starting at the photoreceptor outer segments. Hypertrophy of Müller cells was a concomitant finding. Retinal detachment represents a sequel either to inflammatory processes or trauma.

[Electron microscopic investigation of CD4+ lymphocyte cell line C8166 after infection with simian immunodeficiency virus (SIV)]. / Elektronenmikroskopische Untersuchung an der CD4+ Lymphozytenzellkultur C8166 nach Infektion mit dem Simian-Immunodefiency-Virus (SIV).

The SIV infection of rhesus macaques (Macaca mulatta) is the most appropriate animal model in HIV research. The permanent human T-cell line C8166 is used for in vitro SIV propagation. This paper describes ultrastructural features of the cells after infection with SIVmac. The C8166 cells are ultrastructurally characterized by a heterogenous morphology which is independent of the infection. SIV induced cell syncytia are observed 18 hours after infection. Viral particles and budding occur 48 hours p.i with a peak at the day 8. Viral particles present the typical lentiviral morphology. Using the monoclonal antibody anti SIVp28 and ultra small (0.8 nm) immunogold-silver enhancement technique, we are able to demonstrate SIV antigen immunoelectron microscopically. Therefore, this ultrastructural method is suitable to detect SIV antigen in in vivo experiments with C8166 cells from day 8 p.i. serving as positive control.

Ischiopagus tripus conjoined twins in a western lowland gorilla (Gorilla gorilla).

Conjoined twinning is rare in man and non-human primates. The current report describes a case of ischiopagus tripus conjoined Western Lowland gorilla (Gorilla gorilla) twins. The female twins were joined at the umbilical and pelvic region, involving the liver, xiphoid, umbilicus, body wall and skin. Computed tomography revealed two complete spines. The combined pelvic space was formed by two sacra, each connected with two iliac bones. The twins were only conjoined by a common pubis. Cause of death was attributed to cardiac and circulatory collapse resulting from a large patent foramen ovale (8 mm in diameter) of one twin and neonatal asphyxia.

Oncocytic adrenocortical carcinoma in a putty-nosed monkey (Cercopithecus nictitans) with hyperadrenocorticism.

Oncocytic adrenocortical tumours are rare in man and have never been described in non-human primates. An oncocytic adrenocortical carcinoma was identified in an 18-year-old female putty-nosed monkey (Cercopithecus nictitans) with hyperadrenocorticism and invasive aspergillosis. Microscopically, the tumour consisted of large cells with abundant eosinophilic, granular cytoplasm containing numerous mitochondria as identified by electron microscopy. Tumour cells had large nuclei with occasional intranuclear cytoplasmic pseudoinclusions. Immunohistochemically, tumour cells expressed vimentin, synaptophysin and neuron-specific enolase, while they were negative for cytokeratin, chromogranin-A, melan-A and S100.

Mucocutaneous candidiasis in a mandrill (Mandrillus sphinx).

An adult male mandrill (Mandrillus sphinx) suffered from chronic ulceration of the facial and gluteal skin and the oral and nasal mucosa. The ulcers were resistant to therapy and led to deterioration in the general condition of the animal. Microscopical examination revealed a severe, chronic, multifocal, granulomatous and eosinophilic dermatitis and panniculitis. There was also stomatitis and rhinitis with numerous intralesional fungal elements. These organisms were identified by immunohistochemistry, transmission electron microscopy, polymerase chain reaction and fungal culture as Candida albicans. Species identification was confirmed by MALDI-TOF mass spectrometry. A specific predisposing immunosuppressive factor for the deep chronic mucocutaneous candidiasis was not identified; however, social stress and/or a primary defect in cell-mediated immunity could not be excluded as possible causes for a predisposing immunodeficiency in the animal.

The pathology of experimental poxvirus infection in common marmosets (Callithrix jacchus): further characterization of a new primate model for orthopoxvirus infections.

Zoonotic orthopoxvirus (OPV) can induce severe disease in man and the virus has potential for use in bioterrorism. New vaccines and therapeutics against OPV infections must be tested in animal models. The aim of this study was to characterize the clinical course and pathology of a new OPV isolate, calpox virus, which is infectious in marmosets. Infection experiments were performed with 28 common marmosets (Callithrix jacchus) exposed to different challenge doses of calpox virus by the intravenous, oropharyngeal and intranasal (IN) routes. The median marmoset IN infectious dose corresponded to 8.3 × 10(2)plaque forming units of calpox virus. Infected animals developed reproducible clinical signs and died within 4-15 days post infection. Characteristic pox-like lesions developed in affected organs, particularly in the skin, mucous membranes, lymph nodes, liver and spleen. Calpox virus disease progression and pathological findings in the common marmoset appear to be consistent with lethal OPV infections in man and in other non-human primate (NHP) models. IN inoculation with low virus doses mimics the natural route of the human variola virus infection. Thus, the marmoset model of calpox virus infection can be considered to be relevant to investigation of the mechanisms of OPV pathogenesis and pathology and for the evaluation of new vaccines and antiviral therapies.