A large number of viruses have been described in many different reptiles. These viruses include arboviruses that primarily infect mammals or birds as well as viruses that are specific for reptiles. Interest in arboviruses infecting reptiles has mainly focused on the role reptiles may play in the epidemiology of these viruses, especially over winter. Interest in reptile specific viruses has concentrated on both their importance for reptile medicine as well as virus taxonomy and evolution. The impact of many viral infections on reptile health is not known. Koch’s postulates have only been fulfilled for a limited number of reptilian viruses. As diagnostic testing becomes more sensitive, multiple infections with various viruses and other infectious agents are also being detected. In most cases the interactions between these different agents are not known. This review provides an update on viruses described in reptiles, the animal species in which they have been detected, and what is known about their taxonomic positions.

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The Iridoviridae is a family of large, icosahedral viruses with double-stranded DNA genomes ranging in size from 103 to 220 kbp. Members of the subfamily Alphairidovirinae infect ectothermic vertebrates (bony fish, amphibians and reptiles), whereas members of the subfamily Betairidovirinae mainly infect insects and crustaceans. Infections can be either covert or patent, and in vertebrates they can lead to high levels of mortality among commercially and ecologically important fish and amphibians. This is a summary of the current International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Iridoviridae, which is available at www.ictv.global/report/iridoviridae.

Herpesviruses are well-known infectious agents with remarkably wide host ranges. Starting in 1975 (33), several reports have documented the presence of herpesvirus-like particles in land tortoises and freshwater and marine turtles (5, 7-9, 11, 15, 17, 19-23, 27-29, 30, 38). Recent investigations have revealed an association between the presence of herpesvirus and an upper respiratory tract disease in Mediterranean tortoises [spur-thighed tortoise (Testudo graeca) and Hermann's tortoise (T. hermanni)] (5,8,9,17,20,23,(27)(28)(29)30).In tortoises with herpesvirus infection, clinical signs range from a mild conjunctivitis to a severe stomatitis-glossitis and pharyngitis. Diphtheritic plaques can be observed on the dorsal surface of the tongue and on the hard palate of infected tortoises. Frequently, a clear serous to a mucopurulent nasal discharge is present. Signs of central nervous system disease have also been reported in Mediterranean tortoises with herpesvirus infection (17).Eosinophilic intranuclear inclusions, often seen in multiple tissues, are particularly prominent in tortoises with pharyngitis and glossitis. As seen with transmission electron microscopy, inclusions consist of numerous viral particles. The morphology and morphogenesis have been used to categorize the virus as herpesvirus.A diagnosis of herpesvirus infection is often made based solely upon light or electron microscopy findings. Antemortem diagnosis can be made using biopsy specimens of oral lesions. A serum neutralization (SN) test has been developed but is limited in its application since it is only available in a few research laboratories in Europe (10). In addition, time is a limiting factor with the SN test. Ten to 14 days are required to obtain the final reading and a laborious procedure is required. An easier and faster but equally reliable serodiagnostic test is needed. In this report, we describe the development of an enzyme-linked immunosorbent assay (ELISA) that can be used to monitor the exposure to herpesvirus of free-range, private, and zoo collections of tortoises. MATERIALS AND METHODSViruses. Herpesvirus isolates HV1976 and HV4295/7R/95 were used as antigens in the ELISAs and immunoblotting. HV1976 was isolated from a captive Hermann's tortoise from the United States (Washington), while HV4295/7R/95 was isolated from a captive Hermann's tortoise in Germany during a herpesvirus outbreak in a private collection (27).Antigen preparation for ELISA. The herpesvirus isolates were grown in terrapene heart cell monolayers (TH-1; ATCC-CCL 50 Sub-line B1; American Type Culture Collection, Rockville, Md.) in T-150 plastic flasks with ventilated caps (Corning, Rochester, N.Y.) for use as ELISA antigens. The TH-1 cells were grown in Dulbecco's modified Eagle's medium F12 (Gibco BRL, Grand Island, N.Y.) with 5% fetal bovine serum (Sigma, St. Louis, Mo.), gentamicin (60 mg/liter) (Sigma), penicillin G (120,000 U/liter), streptomycin (120,000 U/liter), and amphotericin B (300 g/liter) (ABAM; Sigma). Infected cell monolayers were scraped a...

A virus was isolated from tissues of 2 diseased Hermann's tortoises (Testudo hermanni) and preliminarily characterized as an iridovirus. This conclusion was based on the presence of inclusion bodies in the cytoplasm of infected cells, sensitivity to chloroform, inhibition of virus replication by 5-iodo-2'-desoxyuridine and the size and icosahedral morphology of viral particles. The virus was able to replicate in several reptilian, avian and mammalian cell lines at 28 degrees C, but not at 37 degrees C. Restriction enzyme analysis showed resistance of the ral DNA to digestion with HpaII due to methylation of the internal cytosine at CCGG sequences. Part of the genomic region encoding the major capsid protein was amplified by PCR and subjected to sequence analysis. Comparative analysis of the obtained nucleotide sequence revealed that the isolate is closely related to frog virus 3, the type species of the genus Ranavirus.

Various studies were done during a spontaneous outbreak of stomatitis-rhinitis-complex (mouth rot) in a collection of Mediterranean land tortoises (21 Teftudo bermanni, Hermann's tortoises, and three Tesfudo Rruecu, spur-thighed tortoises) in southern Germany. These studies were intended to help diagnose the causative agent, establish a possible diagnostic method in vivo and provide information on the efficacy of aciclovir and ganciclovir against chelonian herpesviruses. Thirteen 7: hemunni and no T gruecu died within a period of 6 weeks following the introduction of one apparently healthy Tgruecu. Two of the dead Testudo bermunni were submitted for post-mortem examination. In addition, blood samples from 11 of the 12 tortoises still surviving at the beginning of this study were cultured for virus content and for the presence of neutralizing antibodes to chelonian herpesviruses and swabs from conjunctiva, pharynx and cloaca were cultured for the presence of viruses. Herpesviruses were isolated from tissues of the two dead Testudo bermunni (tongue, intestine, trachea, lung, spleen, heart and brain). Peripheral leukocytes from one of 11 blood samples were positive for herpesvirus isolation, indicating viremia in at least one animal. Nine of 11 pharyngeal swabs but none of the conjunctival and cloacal swabs yielded herpesviruses. Circulating neutralizing antibodies were present in two of two tested 7: graeca, but absent in all of the nine samples from 7: hernzanni. Aciclovir and ganciclovir were effective when tested in vitm against one of the herpesvirus isolates.

Ranaviruses in amphibians and fish are considered emerging pathogens and several isolates have been extensively characterized in different studies. Ranaviruses have also been detected in reptiles with increasing frequency, but the role of reptilian hosts is still unclear and only limited sequence data has been provided. In this study, we characterized a number of ranaviruses detected in wild and captive animals in Europe based on sequence data from six genomic regions (major capsid protein (MCP), DNA polymerase (DNApol), ribonucleoside diphosphate reductase alpha and beta subunit-like proteins (RNR-α and -β), viral homolog of the alpha subunit of eukaryotic initiation factor 2, eIF-2α (vIF-2α) genes and microsatellite region). A total of ten different isolates from reptiles (tortoises, lizards, and a snake) and four ranaviruses from amphibians (anurans, urodeles) were included in the study. Furthermore, the complete genome sequences of three reptilian isolates were determined and a new PCR for rapid classification of the different variants of the genomic arrangement was developed. All ranaviruses showed slight variations on the partial nucleotide sequences from the different genomic regions (92.6–100%). Some very similar isolates could be distinguished by the size of the band from the microsatellite region. Three of the lizard isolates had a truncated vIF-2α gene; the other ranaviruses had full-length genes. In the phylogenetic analyses of concatenated sequences from different genes (3223 nt/10287 aa), the reptilian ranaviruses were often more closely related to amphibian ranaviruses than to each other, and most clustered together with previously detected ranaviruses from the same geographic region of origin. Comparative analyses show that among the closely related amphibian-like ranaviruses (ALRVs) described to date, three recently split and independently evolving distinct genetic groups can be distinguished. These findings underline the wide host range of ranaviruses and the emergence of pathogen pollution via animal trade of ectothermic vertebrates.

Ranaviruses infect fish, amphibians, and reptiles. The present study was conducted to compare the persistence of amphibian and reptilian ranaviruses in a pond habitat. The 4 viruses used in this study included 2 amphibian ranaviruses, Frog virus 3 (FV3, the type species of the genus Ranavirus) and an isolate from a frog, and 2 ranaviruses of reptilian origin (from a tortoise and from a gecko). A sandwich germ-carrier technique was used to study the persistence of these viruses in sterile and unsterile pond water (PW) and soil obtained from the bank of a pond. For each virus, virus-loaded carriers were placed in each of the 3 substrates, incubated at 4 and 20°C, and titrated at regular intervals. Serial data were analyzed using a linear regression model to calculate T-90 values (time required for 90% reduction in the virus titer). Resistance of the viruses to drying was also studied. All 4 viruses were resistant to drying. At 20°C, T-90 values of the viruses were 22 to 31 d in sterile PW and 22 to 34 d in unsterile PW. Inactivation of all 4 viruses in soil at this temperature appeared to be non-linear. T-90 values at 4°C were 102 to 182 d in sterile PW, 58 to 72 d in unsterile PW, and 30 to 48 d in soil. Viral persistence was highest in the sterile PW, followed by the unsterile PW, and was lowest in soil. There were no significant differences in the survival times between the amphibian and reptilian viruses. The results of the present study suggest that ranaviruses can survive for long periods of time in pond habitats at low temperatures. KEY WORDS: Ranaviruses · Pond water · Persistence · Soil Resale or republication not permitted without written consent of the publisherDis Aquat Org 98: [177][178][179][180][181][182][183][184] 2012 transmitted to healthy salamanders after putting them in the water where infected salamanders were previously kept, even after passing the water through 0.45 µm pore size filters. In one transmission study, it has been observed that salamanders acquired infection after water-bath exposure to ATVcontaminated water and also transferred the infection to other healthy individuals (Brunner et al. 2007). The exposure of Rana sylvatica tadpoles to sediments collected from a pond where a ranavirus die-off had occurred resulted in the development of infection in the exposed individuals (Harp & Petranka 2006). Similarly, experimentally inoculated moist sediments also transmitted ATV infection and caused mortality in larval salamanders (Brunner et al. 2007). These studies indicate that in a small pond habitat, contaminated water and soil can be a potential source of virus transmission to susceptible animals.There is scarcity of data on the environmental persistence of iridoviruses infecting reptiles and amphibians. One report shows that the infectivity of ATV-contaminated water was lost after a 2 wk incubation at 25°C (Jancovich et al. 1997). Langdon (1989) observed that a fish ranavirus, closely related to amphibian ranaviruses, can survive for 97 d in water at 15°C. A comparison ...