Isolation and characterization of simian adenoviruses isolated in association with an outbreak of pneumoenteritis in vervet monkeys (Cercopithecus aethiops)

Detection and Molecular Characterization of Adenoviruses in Captive and Free-Roaming African Green Monkeys (Chlorocebus sabaeus): Evidence for Possible Recombination and Cross-Species Transmission

In the present study, 31 samples (12 fecal, 9 nasal and 10 rectal swabs) from 28/92 (30.43%, 10 captive and 18 free-roaming African green monkeys (AGMs, Chlorocebus sabaeus)) apparently healthy AGMs in the Caribbean Island of St. Kitts tested positive for adenoviruses (AdVs) by DNA-dependent DNA polymerase (pol)-, or hexon-based screening PCR assays. Based on analysis of partial deduced amino acid sequences of Pol- and hexon- of nine AGM AdVs, at least two AdV genetic variants (group-I: seven AdVs with a Simian mastadenovirus-F (SAdV-F)/SAdV-18-like Pol and hexon, and group-II: two AdVs with a SAdV-F/SAdV-18-like Pol and a Human mastadenovirus-F (HAdV-F)/HAdV-40-like hexon) were identified, which was corroborated by analysis of the nearly complete putative Pol, complete hexon, and partial penton base sequences of a representative group-I (strain KNA-08975), and -II (KNA-S6) AdV. SAdV-F-like AdVs were reported for the first time in free-roaming non-human primates (NHPs) and after ~six decades from captive NHPs. Molecular characterization of KNA-S6 (and the other group-II AdV) indicated possible recombination and cross-species transmission events involving SAdV-F-like and HAdV-F-like viruses, corroborating the hypothesis that the evolutionary pathways of HAdVs and SAdVs are intermingled, complicated by recombination and inter-species transmission events, especially between related AdV species, such as HAdV-F and SAdV-F. To our knowledge, this is the first report on detection and molecular characterization of AdVs in AGMs.

Enteric Viruses of Nonhuman Primates

The phylogenetic relationship of nonhuman primates to man implies that many of these animals could serve as surrogates for studies of diseases of man. Many nonhuman primate species are susceptible not only to viruses of human origin but also to nonhuman primate viruses that are counterparts of viruses of man. All monkeys and great apes do not respond similarly to an antigenic stimulus. Some agents are highly pathogenic for one species and completely innocuous for another. For example, poliovirus causes disease and fatalities in great apes, but picornaviruses given orally cause few lesions in most nonhuman primates. Other enteroviruses (coxsackie-, echoviruses) have caused disease in nonhuman primates. It is difficult to separate viruses into distinct categories according to their anatomic affinities. Many viruses not considered to be enteric may be recovered from the intestinal tract. Adenoviruses, both human and nonhuman strains, which are not considered enteric viruses, nonetheless are recovered frequently from the intestinal tract. Adult animals show little evidence of disease, with the possible exception of diarrhea, after adenovirus infection. Newborns, however, may respond with a fatal pneumoenteritis. Adenovirus may be associated with diseases in organs other than the intestines. The reoviruses, which may be recovered from the intestinal tract, also are generally innocuous. Rotaviruses as pathogens in nonhuman primates are presently under study, and it is suspected that rotaviruses of man may produce experimental disease in nonhuman primates. Production of diabetes by several of the enteric viruses has been suggested but not demonstrated conclusively.

Adenoviral Pancreatitis in Rhesus Monkeys: Current Knowledge

Features and pathogenesis of adenoviral pancreatitis in rhesus monkeys were studied with an immunofluorescence staining procedure on tissues from two previously documented cases. Fluorescing adenovirus antigen in epithelial cells of the pancreatic ducts, duodenum, and jejunum suggests that under as yet undefined conditions, a primary adenovirus infection of the gastrointestinal tract ascends to the pancreatic parenchyma via pancreatic ducts.

In a retrospective survey, over 3,000 microslides of pancreas taken at necropsy from several species of nonhuman primates (1,002 animals) were studied to determine the incidence of and species susceptibility to adenoviral pancreatitis. Other than the two documented cases from our files, we found comparable lesions in only one rhesus monkey. Adenoviral pancreatitis seems to be a distinct entity in rhesus monkeys, and it should be considered when pancreatitis is found in this species. Our findings also suggest a possible viral cause for some cases of pancreatitis in man.

Taxonomy proposal for Old World monkey adenoviruses: characterisation of several non-human, non-ape primate adenovirus lineages

A species classification regarding Old World monkey adenoviruses is proposed. We determined the nucleotide sequences of PCR-amplified fragments from the genes of the IVa2, DNA-dependent DNA polymerase, penton base, and hexon proteins from every simian adenovirus (SAdV) serotype that originated from Old World monkeys for which the full genome sequence had not yet been published. We confirmed that the majority of Old Word monkey SAdVs belong to two previously established species. Interestingly, one is the most recently established human AdV species, Human mastadenovirus G, which includes a single human virus, HAdV-52, as well as SAdV-1, -2, -7, -11, -12, and -15. The other approved species, Simian mastadenovirus A includes SAdV-3, -4, -6, -9, -10, -14, and -48. Several SAdVs (SAdV-5, -8, -49, -50) together with baboon AdV-1 and rhesus monkey AdV strains A1139, A1163, A1173, A1258, A1285, A1296, A1312, A1327 and A1335 have been proposed to be classified into an additional species, Simian mastadenovirus B. Another proposed species, Simian mastadenovirus C has been described for SAdV-19, baboon AdV-2/4 and -3. Our study revealed the existence of four additional AdV lineages. The corresponding new candidate species are Simian mastadenovirus D (for SAdV-13), Simian mastadenovirus E (for SAdV-16), Simian mastadenovirus F (for SAdV-17 and -18), and Simian mastadenovirus G (for SAdV-20). Several biological and genomic properties, such as the host origin, haemagglutination profile, number of fibre genes, and G+C content of the genome, strongly support this classification. Three SAdV strains originating from the American Type Culture Collection turned out to be mixtures of at least two virus types, either of the same species (SAdV-12 and -15 types from Human mastadenovirus G) or of two different species (SAdV-5 types from Simian mastadenovirus B and Human mastadenovirus G).

Adenoviruses in fecal samples from asymptomatic rhesus macaques, United States

Isolates contained fiber genes similar to those of adenovirus strains that cause infectious diarrhea in humans.

Adenoviruses can cause infectious diarrheal disease or respiratory infections in humans; 2 recent reports have indicated probable human infection with simian adenoviruses (SAdVs). To assess the possibility of animal-to-human transmission of SAdVs, we tested fecal samples from asymptomatic rhesus macaques housed in 5 primate facilities in the United States and cultured 23 SAdV isolates. Of these, 9 were purified and completely sequenced; 3 SAdV samples from the American Type Culture Collection (SAdV-6, SAdV-18, and SAdV-20) were also completely sequenced. The sequence of SAdV-18 was closely related to that of human adenovirus F across the whole genome, and the new isolates were found to harbor 2 fiber genes similar to those of human adenovirus (HAdV) strains HAdV-40 and HAdV-41, which can cause infectious diarrhea. The high prevalence of adenoviruses in fecal samples from asymptomatic rhesus macaques and the similarity of the isolates to human strains indicates the possibility of animal-to-human transmission of SAdVs.

Novel adenoviruses in wild primates: a high level of genetic diversity and evidence of zoonotic transmissions

Adenoviruses (AdVs) broadly infect vertebrate hosts, including a variety of nonhuman primates (NHPs). In the present study, we identified AdVs in NHPs living in their natural habitats, and through the combination of phylogenetic analyses and information on the habitats and epidemiological settings, we detected possible horizontal transmission events between NHPs and humans. Wild NHPs were analyzed with a pan-primate AdV-specific PCR using a degenerate nested primer set that targets the highly conserved adenovirus DNA polymerase gene. A plethora of novel AdV sequences were identified, representing at least 45 distinct AdVs. From the AdV-positive individuals, 29 nearly complete hexon genes were amplified and, based on phylogenetic analysis, tentatively allocated to all known human AdV species (Human adenovirus A to Human adenovirus G [HAdV-A to -G]) as well as to the only simian AdV species (Simian adenovirus A [SAdV-A]). Interestingly, five of the AdVs detected in great apes grouped into the HAdV-A, HAdV-D, HAdV-F, or SAdV-A clade. Furthermore, we report the first detection of AdVs in New World monkeys, clustering at the base of the primate AdV evolutionary tree. Most notably, six chimpanzee AdVs of species HAdV-A to HAdV-F revealed a remarkably close relationship to human AdVs, possibly indicating recent interspecies transmission events.

Adenoviral hepatitis in a SIV-infected rhesus monkey (Macaca mulatta)

BACKGROUND

A 5-year-old female rhesus monkey infected with simian immunodeficiency virus became clinically suspicious with anorexia, increasing weakness and apathy eighty-five weeks after the tonsillar virus inoculation and was euthanised due to a poor prognosis.

METHODS AND RESULTS

Postmortal examinations revealed a severe multifocal to coalescing necotizing hepatitis with numerous intranuclear basophilic inclusion bodies. Transmission electron microscopy of the liver resulted in the finding of adenovirus like particles arranged in paracrystalline arrays within the nuclei of hepatocytes.

CONCLUSION

The SIV infected rhesus monkey suffered from an adenovirus included necortizing hepatitis, an extremely rare organ manifestation of adenovirus infection in nonhuman primates.

Pancreatitis associated with an adenovirus in a rhesus monkey

A juvenile Rhesus monkey died suddenly while being conditioned for tissue culture studies. A diagnosis of necrotizing pancreatitis associated with adenovirus was made on the basis of the demonstration by electron microscopy of paracrystalline arrays of viral particles and granular and fibrillar inclusions in necrotic pancreatic acinar cells. This is the first description of necrotizing pancreatitis in a nonhuman primate. Adenovirus should be considered in the etiology of pancreatitis in nonhuman primates.

Technique for viral neutralization antibody surveys in primary microcultures

A simplified, microplate tissue culture procedure is described which facilitates neutralization antibody surveys on large numbers of sera. A comparison of the micromethod with that employing standard tube cultures indicates it to be as sensitive and far more economical.