Detection of known and novel adenoviruses in cattle wastes via broad-spectrum primers

Isolation and complete genomic characterization of a Movar 33/63-like Japanese bovine herpesvirus 4 from a calf with respiratory disease

Bovine herpesvirus 4 (BoHV-4) is an indigenous virus in cattle prevalent mainly in North and South American countries and European countries, but the genomic sequences and genetic characteristics of Japanese strains have not been reported. BoHV-4 is suspected, but not proven, to be associated with various diseases. In the present study, we isolated BoHV-4 from a 10-month-old Japanese Black calf with respiratory symptoms in Japan. To identify the genetic characteristics of the isolate named strain SG20, complete genome sequencing was performed using a combination of next-generation and Sanger sequencing technologies. The complete long unique coding region (LUR) of SG20 was found to comprise 108,819 nucleotides with 41.4% GC content and contain at least 78 open reading frames. It shares 83.4 to 99.3% overall nucleotide identity with six BoHV-4 strains available in the database. The deduced amino acid sequence alignment revealed that SG20 contains genotype 1-specific features of BoHV-4, such as amino acid substitutions and insertions within the glycoprotein B region. Phylogenetic analyzes based on the nucleotide sequences of ORF20 indicated that the virus belonged to genotype 1 (Movar 33/63-like group). The strain was also analyzed using the complete LUR and placed in the same clade as a strain recently isolated from China, but it was distinct from American and European BoHV-4 strains of genotype 1. Although further genomic and epidemiologic information is needed, our results help elucidate the molecular epidemiology of BoHV-4 and provide a foundation for future studies.

Ovine adenoviruses infecting sheep and goats in Türkiye: detection and molecular characterization of three different types

Adenoviruses (AdVs) have been detected in a wide variety of animals. To date, eight types of AdVs in sheep and two types in goats have been identified, which belong to two distinct genera, Mastadenovirus and Atadenovirus. Typically, the term pneumo-enteritis is used to describe adenovirus-induced disease in small ruminants, which has been associated with both enteric and respiratory symptoms of varying severity. The aim of this study was to detect and identify AdVs of small ruminants belonging to the genera Mastadenovirus and Atadenovirus. For this purpose, diagnostic samples (47 lung, 27 intestine, and two pooled tissue samples including intestine and lung) from 49 small ruminants (39 sheep and 10 goats) were used. Following the viral DNA extraction, PCR was carried out by using the primers targeting the hexon gene in order to detect both mast- and atadenoviruses. Sequencing the amplified fragments revealed the presence of three types of ovine adenovirus (OAdV): OAdV-3, OAdV-4, and OAdV-8. Specifically, OAdV-3 was detected in two sheep and a goat while OAdV-4 and OAdV-8 were found in only one sheep each. There is still limited data on the interaction between the viruses in different adenovirus genera and the detected disease, as well as the genetic diversity of adenoviruses, especially in small ruminants. In conclusion, the detection of AdVs in lung and intestinal tissues of small ruminants in this study suggests that these viruses may have contributed to the disease and/or predisposed to other agents.

Detection and Molecular Characterization of Animal Adenovirus and Astrovirus from Western Maharashtra, India

Astroviruses (AstV) and adenoviruses (AdV) are associated with diarrhoea in young animals. However, the epidemiology and genetic diversity of AstVs and AdVs in animals is not well studied. Hence, the present study was conducted to detect and characterize AstVs and AdVs in calves, piglets and puppies from Western Maharashtra, India. Out of the processed porcine (48), canine (80), and bovine (65) faecal samples, the porcine AstV (PAstV), bovine AstV (BAstV), canine AstV (CAstV), and porcine AdV (PAdV) were detected in 12.5%, 7.69%, 3.75% and 4.1% of samples, respectively. In the RNA-dependent RNA polymerase region-based phylogenetic analysis, the detected BAstV strains grouped with MAstV-28, MAstV-33, and MAstV-35, CAstV strains belonged to MAstV-5; PAstV strains belonged to MAstV-24, MAstV-26, and MAstV-31. However, in hexon gene-based phylogeny, both the detected PAdV were of genotype 3, exhibiting 91.9-92.5% nucleotide identity with Ivoirian and Chinese strains. The study reports first-time BAstVs from calves and PAdV-3 from piglets in India. The study revealed diversity in the circulation of AstVs in tested animals and AdVs in pigs, and suggested that they alone might be associated with other diarrhoea or in combination with other enteric pathogens, thus highlighting the necessity of extensive epidemiological investigations to develop diagnostic tools and control measures.

High Rates of Detection and Molecular Characterization of Porcine Adenovirus Serotype 5 (Porcine mastadenovirus C) from Diarrheic Pigs

Since the first report on isolation of porcine adenovirus serotype 5 (PAdV-5, species Porcine mastadenovirus C (PAdV-C)) from pigs with respiratory illness in Japan in 1987, PAdV-5 have been detected in a few fecal samples from healthy pigs and in some environmental samples. To date, only a single PAdV-5 strain (isolate HNF-70 from 1987) has been analyzed for the complete genome. We report here high detection rates of PAdV-5 (25.74%, 26/101 fecal samples) in diarrheic pigs at 3 different farms in the Caribbean country of Dominican Republic. After a long gap, the complete deduced amino acid sequences of the DNA-dependent DNA polymerase (pol) and hexon of two PAdV-5 strains (GES7 and Z11) were determined, revealing >99% sequence identities between PAdV-5 strains (HNF-70, GES7 and Z11) detected in different parts of the world and during different time periods (1987, and 2020−2021). By phylogenetic analysis, the putative hexon and pol of HNF-70, GES7 and Z11 exhibited similar clustering patterns, with the PAdV-5 strains forming a tight cluster near ruminant AdVs, distinct from the species PAdV-A and -B. GES7 and Z11 retained the various conserved features present in the putative pol and major late promoter region of HNF-70. Considering the paucity of data on current epidemiological status and genetic diversity of PAdV in porcine populations, our findings warrant similar studies on PAdV-5 and other PAdVs in clinically ill and healthy pigs. To our knowledge, this is the first report on detection and molecular characterization of PAdV-5 (PAdV-C) from diarrheic pigs.

Molecular characterization of a bovine adenovirus type 7 (Bovine Atadenovirus F) strain isolated from a systemically infected calf in Germany

Bovine adenovirus 7 (BAdV-7) is an unclassified member of the genus Atadenovirus with a worldwide distribution and has been reported to induce clinical disease of varying severity in infected cattle, ranging from asymptomatic infections to severe enteric or respiratory disease. In this study, we used next-generation sequencing to obtain the first complete genome sequence of a European strain of BadV-7, from pooled spleen and liver tissue obtained from a deceased newborn Limousin calf. Histopathological analysis and electron microscopy showing systemic lesions in multiple organs with intranuclear amphophilic inclusions observed in endothelial cells in multiple peripheral tissues. Virus isolation was readily achieved from tissue homogenate using bovine esophagus cells (KOP-R), a strategy which should facilitate future in vitro or in vivo BAdV-7 studies. Phylogenetic analysis of available genome sequences of BAdV-7 showed that the newly identified strain groups most closely with a recent BAdV-7 strain, SD18-74, from the USA, confirming that this newly identified strain is a member of the Atadenovirus genus. The fiber gene was found to be highly conserved within BAdV-7 strains but was highly divergent in comparison to Ovine adenovirus 7 (OAdV-7) (39.56% aa sequence identity). Furthermore, we report a variable region of multiple tandem repeats between the coding regions of E4.1 and RH5 genes. In summary, the presented pathological and molecular characterization of this case suggests that further research into the worldwide molecular epidemiology and disease burden of BAdV-7 is warranted.

First Report on Detection and Molecular Characterization of Adenoviruses in the Small Indian Mongoose (Urva auropunctata)

Using a broad-range nested PCR assay targeting the DNA-dependent DNA polymerase (pol) gene, we detected adenoviruses in 17 (20.48%) out of 83 fecal samples from small Indian mongooses (Urva auropunctata) on the Caribbean island of St. Kitts. All 17 PCR amplicons were sequenced for the partial pol gene (~300 bp, hereafter referred to as Mon sequences). Fourteen of the 17 Mon sequences shared maximum homology (98.3-99.6% and 97-98.9% nucleotide (nt) and deduced amino acid (aa) sequence identities, respectively) with that of bovine adenovirus-6 (species Bovine atadenovirus E). Mongoose-associated adenovirus Mon-39 was most closely related (absolute nt and deduced aa identities) to an atadenovirus from a tropical screech owl. Mon-66 shared maximum nt and deduced aa identities of 69% and 71.4% with those of atadenoviruses from a spur-thighed tortoise and a brown anole lizard, respectively. Phylogenetically, Mon-39 and Mon-66 clustered within clades that were predominated by atadenoviruses from reptiles, indicating a reptilian origin of these viruses. Only a single mongoose-associated adenovirus, Mon-34, was related to the genus Mastadenovirus. However, phylogenetically, Mon-34 formed an isolated branch, distinct from other mastadenoviruses. Since the fecal samples were collected from apparently healthy mongooses, we could not determine whether the mongoose-associated adenoviruses infected the host. On the other hand, the phylogenetic clustering patterns of the mongoose-associated atadenoviruses pointed more towards a dietary origin of these viruses. Although the present study was based on partial pol sequences (~90 aa), sequence identities and phylogenetic analysis suggested that Mon-34, Mon-39, and Mon-66 might represent novel adenoviruses. To our knowledge, this is the first report on the detection and molecular characterization of adenoviruses from the mongoose.

Molecular characterization of human adenoviruses associated with respiratory infection in Turkey

Human adenoviruses (HAdVs) are responsible for various clinical diseases. Molecular epidemiological studies of respiratory HAdVs are limited in Turkey. To determine the main genotypes and epidemiological characteristics of HAdVs in patients with respiratory symptoms. HAdV PCR-positive extracts of nasal/nasopharyngeal specimens sent to the Turkish Public Health Institution from various cities of Turkey in 2015-2016 were investigated by seminested PCR. Partial sequence analysis of the hexon gene of HAdVs was performed. SPSSv.24.0 was used. A total of 23/68 (33.82%) HAdV-positive samples were amplified. Mastadenovirus B, C, D, and F were detected and mastadenovirus B (10/23; 43.5%) and C (10/23; 43.5%) were predominant strains. Interestingly, HAdV-F known to have gastrointestinal system tropism was detected in two patients with respiratory symptoms. HAdV-B3 was the most prevalent genotype (9/23; 39.1%). Also, HAdV-B7 is defined as a reemerging pathogen. It is noteworthy that there is a cluster of four HAdV-C strains showing a close paraphyletic relationship with HAdV-2/6 intertypic recombination. To our knowledge, this is the first study showing that HAdV-B7 reemerging pathogen circulating in patients with respiratory infections in our country. It is also necessary to emphasize that HAdV-2/6 recombinant strains were detected in this study for the first time in Turkey.

Prevalence of Bovine Leukemia Virus (BLV) and Bovine Adenovirus (BAdV) genomes among air and surface samples in dairy production

We aimed to assess the occurrence of bovine viruses (bovine leukemia virus-BLV and bovine adenovirus-BAdV) at workplaces in traditional dairies and to evaluate the potential role of airborne and surface contamination in spreading of these viruses derived from raw milk. The total amount of 122 samples-including 37 air (bioaerosol), 40 surface, and 45 milk samples-were checked for the presence of BLV and BAdV genomes using RT-qPCR/qPCR method. The study showed that the viruses were present in 7 air (among them 71.4% were BLV-positive and 28.6% were BAdV-positive), 14 surface (among them 85.7% were BLV-positive and 14.3% were BAdV-positive), and 34 milk (all were BLV-positive only) samples. Statistical analysis revealed that both the air and surfaces in studied occupational environment were more frequently contaminated with BLV than with BAdV (Chi-square test: p = 0.002, Fisher's Exact test: p = 0.002). Kruskal-Wallis tests showed significant differences in BLV genome concentrations in the air (p = 0.045) as well as in BLV and BAdV genome concentrations on surfaces (p = 0.005 and p = 0.040, respectively) between studied processing areas. In units of genome copies (gc) per area, the highest concentrations of BLV and BAdV genomes in the air (9.8 × 10¹ ± 1.14 × 10² gc/m³ and 5.4 × 10¹ ± 9.1 × 10¹ gc/m³, respectively) and on surfaces (9.83 × 10² ± 7.41 × 10² gc/100cm² and 2.30 × 10² ± 3.8 × 10² gc/100cm², respectively) were observed in milk reception area. The air and surfaces of pre-production zones were also significantly more contaminated with BAdV genomes compared to production areas (Mann-Whitney test: p = 0.039 and p = 0.029, respectively). This study showed that dairy workers may be exposed to bovine viruses through the inhalation of bioaerosols and contact with contaminated surfaces. To reduce the probability of virus transmission from the raw milk to humans, efficient surface cleaning procedures degrading viral particles should be introduced and the use of personal protection equipment, especially within pre-production zones, should be required. As the raw milk may be a source of bovine viruses, the development of strategies for both the control and eradication of BLV and BAdV among cattle seems to be also urgently needed.

Characterization of the First Genome of Porcine mastadenovirus B (HNU1 Strain) and Implications on Its Lymphoid and Special Origin

Porcine adenoviruses (PAdVs) are classified into three species, PAdV-A, PAdV-B, and PAdV-C. The genomes of PAdV-A and PAdV-C have been well characterized. However, the genome of PAdV-B has never been completely sequenced, and the epidemiology of PAdV-B remains unclear. In our study, we have identified a novel strain of PAdV-B, named PAdV-B-HNU1, in porcine samples collected in China by viral metagenomic assay and general PCR. The genome of PAdV-B-HNU1 is 31,743 bp in length and highly similar to that of California sea lion adenovirus 1 (C. sea lion AdV-1), which contains typical mastadenoviral structures and some unique regions at the carboxy-terminal end. Especially, PAdV-B-HNU1 harbors a dUTPase coding region not clustering with other mastadenoviruses except for C. sea lion AdV-1 and a fiber coding region homologous with galectin 4 and 9 of animals. However, the variance of GC contents between PAdV-B-HNU1 (55%) and C. sea lion AdV-1 (36%) indicates their differential evolutionary paths. Further epidemiologic study revealed a high positive rate (51.7%) of PAdV-B-HNU1 in porcine lymph samples, but low positive rates of 10.2% and 16.1% in oral swabs and rectal swabs, respectively. In conclusion, this study characterized a novel representative genome of a lymphotropic PAdV-B with unique evolutionary origin, which contributes to the taxonomical and pathogenic studies of PAdVs.

Causative agents and epidemiology of diarrhea in Korean native calves

Calf diarrhea caused by infectious agents is associated with economic losses in the cattle industry. The purpose of this study was to identify the causative agents and epidemiological characteristics of diarrhea in Korean native calves (KNC). In total, 207 diarrheal KNC aged less than 7 months were investigated. Fecal samples collected from the rectum were examined for causative agents using polymerase chain reaction (PCR) or real-time PCR and the number of oocysts were counted. Fourteen causative agents were detected from 164 of the 207 diarrheal KNC. Rotavirus was the most common agent (34.8%), followed by Eimeria spp. (31.7%), Escherichia coli (22.0%), Giardia spp. (14.0%), Clostridium difficile (9.8%), bovine viral diarrhea virus (8.5%), coronavirus (7.9%), Cryptosporidium spp. (7.3%), torovirus (6.7%), parvovirus (5.5%), norovirus (4.9%), kobuvirus (1.8%), adenovirus (1.2%), and Salmonella spp. (0.6%). About 95 (57.9%) of 164 calves were infected with a single causative agent and 42.1% were infected by multiple agents. No significant difference was observed in mortality between calves infected with a single agent and multiple agents. The occurrence of diarrhea caused by rotavirus, Eimeria spp., kobuvirus, and Giardia spp. was significantly different based on onset age, and the prevalence of diarrhea caused by rotavirus or C. difficile was significantly different between seasons. This study help the understanding of KNC diarrhea for the development of an effective strategy for disease prevention and control, especially in Eastern provinces of South Korea.

Adenoviruses across the animal kingdom: a walk in the zoo

Adenoviruses (AdVs) infect representatives of numerous species from almost every major vertebrate class, albeit their incidence shows great variability. AdVs infecting birds, reptiles, and bats are the most common and diverse, whereas only one AdV has been so far isolated both from fish and amphibians. The family Adenoviridae is divided into five genera, each corresponding to an independent evolutionary lineage that supposedly coevolved with its respective vertebrate hosts. Members of genera Mastadenovirus and Aviadenovirus seem to infect exclusively mammals and birds, respectively. The genus Ichtadenovirus includes the single known AdV from fish. The majority of AdVs in the genus Atadenovirus originated from squamate reptiles (lizards and snakes), but also certain mammalian and avian AdVs are classified within this genus. The genus Siadenovirus contains the only AdV isolated from frog, along with numerous avian AdVs. In turtles, members of a sixth AdV lineage have been discovered, pending official recognition as an independent genus. The most likely scenario for AdV evolution includes long-term cospeciation with the hosts, as well as occasional switches between closely or, rarely, more distantly related hosts.

Viruses Associated With Foodborne Infections

Foodborne pathogens cause acute and chronic health outcomes of very different durations, severity and mortality, resulting in high costs and burdens to society. The issues of food safety and food poisoning are being increasingly emphasised, particularly in developed countries. Infection/contamination with many agents i.e., bacterial, parasitic and viral entities can result in foodborne illness. This article will focus mainly on viral agents of infection.

A range of different viruses can cause food poisoning/foodborne infection, and infection can result in a myriad of symptoms, ranging from mild, acute disease to chronic, debilitating disease and even death. Due to the inherent differences between bacteria and viruses, namely the fact that viruses do not replicate in food, while bacteria do, viruses are frequently difficult to detect. This is compounded by the fact that many of the viruses associated with enteric disease do not replicate in cell culture. These factors can lead to a lag between reporting, detection and analysis of foodborne viruses versus bacterial agents. Despite these constraints, it is now evident that there are both well-established and emerging viruses implicated in foodborne infections, and the role of molecular detection and characterisation is becoming increasingly important.

Molecular detection and genotypic characterization of enteric adenoviruses in a hospital wastewater

Hospital wastewater (HWW) represents a major source of the diffusion of many antibiotics and some toxic pathogenic microorganisms in the aquatic environment. Sanitation services play a critical role in controlling transmission of numerous waterborne pathogens, especially enteric human adenoviruses (HAdVs) that can cause acute gastroenteritis. This study intended to evaluate the human adenoviruses (HAdVs) detection rates, to determine the genotype of these viruses and to assess the efficiency of HAdVs removal in hospital pilot wastewater treatment plant (PWWTP) in Tunis City, Tunisia. Therefore, hospital wastewater samples (n = 102) were collected during the study year from the two biological wastewater treatment techniques: natural oxidizing ponds and the rotating biological disks or biodisks. Nested polymerase chain reaction (Nested PCR) was used to evaluate the HAdVs detection rates. The genotype of HAdVs positive samples was achieved by the sequencing of the PCR products. HAdVs were detected in 64% (65/102) of positive wastewater samples. A substantial increase in the frequencies of HAdVs was observed at the exit of the two wastewater treatment techniques studied. The typing of HAdVs species F showed the occurrence of only HAdVs type 41. This data acquired for the first time in Tunisia showed high persistence and survival of HAdVs in the two biological wastewater treatment techniques experienced, and mainly highlighted the poor virological quality of the treated wastewater intended for recycling, agriculture reuse, and discharges into the natural receiving environments. Consequently, tertiary wastewater treatment appeared necessary in this case to decrease the load of enteric viruses flowing in the water environment.

Evolving views on bovine respiratory disease: An appraisal of selected key pathogens - Part 1

Bovine respiratory disease (BRD) is one of the most commonly diagnosed causes of morbidity and mortality in cattle and interactions of factors associated with the animal, the pathogen and the environment are central to its pathogenesis. Emerging knowledge of a role for pathogens traditionally assumed to be minor players in the pathogenesis of BRD reflects an increasingly complex situation that will necessitate regular reappraisal of BRD pathogenesis and control. This review appraises the role of selected key pathogens implicated in BRD pathogenesis to assess how our understanding of their role has evolved in recent years.

Using Patient-Specific Induced Pluripotent Stem Cells and Wild-Type Mice to Develop a Gene Augmentation-Based Strategy to Treat CLN3-Associated Retinal Degeneration

Juvenile neuronal ceroid lipofuscinosis (JNCL) is a childhood neurodegenerative disease with early-onset, severe central vision loss. Affected children develop seizures and CNS degeneration accompanied by severe motor and cognitive deficits. There is no cure for JNCL, and patients usually die during the second or third decade of life. In this study, independent lines of induced pluripotent stem cells (iPSCs) were generated from two patients with molecularly confirmed mutations in CLN3, the gene mutated in JNCL. Clinical-grade adeno-associated adenovirus serotype 2 (AAV2) carrying the full-length coding sequence of human CLN3 was generated in a U.S. Food and Drug Administration-registered cGMP facility. AAV2-CLN3 was efficacious in restoring full-length CLN3 transcript and protein in patient-specific fibroblasts and iPSC-derived retinal neurons. When injected into the subretinal space of wild-type mice, purified AAV2-CLN3 did not show any evidence of retinal toxicity. This study provides proof-of-principle for initiation of a clinical trial using AAV-mediated gene augmentation for the treatment of children with CLN3-associated retinal degeneration.

Clinicopathological features of 11 suspected outbreaks of bovine adenovirus infection and development of a real-time quantitative PCR to detect bovine adenovirus type 10

CASE HISTORY

A retrospective study was conducted to investigate 11 outbreaks of presumptive fatal adenovirus infection diagnosed through two New Zealand diagnostic laboratories during 2014 and 2015. Outbreaks occurred in 6-12-month-old Friesian or Friesian cross cattle during autumn, winter and spring. Individual outbreaks were short in duration, with mortality rates ranging from 3/250 to 20/600 (1.2 to 3.3%).

CLINICAL AND PATHOLOGICAL FINDINGS

Clinical signs included severe diarrhoea, depression, recumbency, and death. Post-mortem examination revealed congestion and oedema of the alimentary tract and fluid to haemorrhagic intestinal contents. Histopathological lesions were characterised by congestion and haemorrhage of the alimentary tract mucosa, oedema of the submucosa, and mild interstitial inflammation in the kidneys. Large basophilic intranuclear inclusion bodies were identified in vascular endothelial cells of the alimentary tract in 11/11 cases and of the kidney in 8/9 cases.

MOLECULAR TESTING

A real-time quantitative PCR (qPCR) assay was designed to detect bovine adenovirus type 10 (BAdV-10) using hexon gene sequences available in GenBank. DNA extracted from a field case and confirmed by sequencing was used as a positive control. The qPCR had a reaction efficiency of 101% (R(2)=0.99) and the limit of detection was <10 DNA copies/reaction. The qPCR detected BAdV-10 in formalin-fixed paraffin-embedded (FFPE) tissue from 10/11 cases. DNA sequencing of PCR products from nine of these cases showed them to be identical to BAdV-10 sequences in GenBank. For the PCR-negative case, the PCR product had a hexon sequence 99% similar to bovine adenovirus Wic isolate Ma20-1, a close relative of BadV-10.

DIAGNOSIS

Bovine adenovirus type 10 was identified in FFPE tissues from cattle with histopathological evidence of adenovirus infection.

CLINICAL RELEVANCE

Bovine adenoviruses, and especially BAdV-10, should be considered in the differential diagnosis for acute enteric disease and death in young cattle. The qPCR detected BAdV-10 from FFPE tissue of cattle with suspected adenoviral infection diagnosed by histopathology. However results should be interpreted in light of clinical and pathological findings due to the possibility of adenovirus shedding by healthy cattle and the presence of pathogenic adenoviruses other than BAdV-10.

Adenovirus in Rural Côte D'Ivoire: High Diversity and Cross-Species Detection

The Taï region in Western Côte d'Ivoire is characterized by extensive overlap of human and animal habitats. This could influence patterns of adenovirus transmission between humans and domestic animals. Fecal samples from humans and various domestic animals were tested for the presence of adenoviruses by PCR. Phylogenetic and species delineation analyses were performed to further characterize the adenoviruses circulating in the region and to identify potential cross-species transmission events. Among domestic animals, adenovirus shedding was frequent (21.6% of domestic mammals and 41.5% of chickens) and the detected strains were highly diverse, several of them representing novel types. Although no evidence for zoonotic transmission of animal adenovirus was obtained, the present study provides concordant evidence in favor of common cross-species transmission of adenoviruses between different animal species and first indications for adenovirus transmission from humans to animals. These findings underline the thus far underestimated importance of reverse zoonotic transmission of viruses and of the role of domestic animals as pathogen reservoirs, "bridge species," or intermediate hosts.

A novel strain of porcine adenovirus detected in urinary bladder urothelial cell culture

Contamination of cell cultures is the most common problem encountered in cell culture laboratories. Besides the secondary cell contaminations often occurring in the cell laboratories, the contaminations originating from donor animal or human tissue are equally as common, but usually harder to recognize and as such require special attention. The present study describes the detection of porcine adenovirus (PAdV), strain PAdV-SVN1 in cultures of normal porcine urothelial (NPU) cells isolated from urinary bladders of domestic pigs. NPU cell cultures were evaluated by light microscopy (LM), polymerase chain reaction (PCR), and additionally assessed by transmission electron microscopy (TEM). Characteristic ultrastructure of virions revealed the infection with adenovirus. The adenoviral contamination was further identified by the sequence analysis, which showed the highest similarity to recently described PAdV strain PAdV-WI. Additionally, the cell ultrastructural analysis confirmed the life-cycle characteristic for adenoviruses. To closely mimic the in vivo situation, the majority of research on in vitro models uses cell cultures isolated from human or animal tissue and their subsequent passages. Since the donor tissue could be a potential source of contamination, the microbiological screening of the excised tissue and harvested cell cultures is highly recommended.

Detection of human adenovirus, rotavirus and enterovirus in water samples collected on dairy farms from Tenente Portela, Northwest of Rio Grande do Sul, Brazil

Viral gastroenteritis and other waterborne diseases are a major concern for health in Brazil. A number of studies were conducted about the presence of viruses on water samples from Brazilian areas. However, the knowledge about the occurrence of viral contamination of drinking water sources in rural settings of the country is insufficient. On the present work, 15 samples from 5 dairy farms located at the municipality of Tenente Portela were collected and analysed for the presence of human adenoviruses (HAdV), as well as human enteroviruses (EV) and rotaviruses (RV). HAdV was present on 66.66% of the water samples, and have been found in all samples from artesian wells and springs, which are used as sources of drinking water for the individuals inhabiting those farms. EV and RV found only in one sample each. The detection rates of HAdV on the water from these dairy farms are alarming and point towards a situation of elevated environmental contamination by fecal microorganisms of human origin and poor basic sanitation conditions.

Development of a quantitative immunocapture real-time PCR assay for detecting structurally intact adenoviral particles in water

Development of rapid, sensitive and specific methods for detection of infectious enteric viruses in water is challenging but crucial for gaining reliable information for risk assessment. An immunocapture real-time PCR (IC-qPCR) was designed to detect jointly the two major viral particle components, i.e. the capsid protein and the viral genome. Targeting both constituents helps circumventing the technical limits of cell culture approaches and the inability of PCR based methods to predict the infectious status. Two waterborne pathogenic virus models, human adenovirus types 2 and 41, were chosen for this study. IC-qPCR showed a detection limit of 10MPNCU/reaction with a dynamic range from 10(2) to 10(6)MPNCU/reaction. Sensitivity was thus 100-fold higher compared to ELISA-based capture employing the same anti-hexon antibodies. After optimisation, application on environmental water samples was validated, and specificity towards the targeted virus types was obtained through the qPCR step. Heat-treated pure samples as well as surface water samples brought evidence that this method achieves detection of encapsidated viral genomes while excluding free viral genome amplification. As a consequence, adenovirus concentrations estimated by IC-qPCR were below those calculated by direct qPCR. The results demonstrate that the IC-qPCR method is a sensitive and rapid tool for detecting, in a single-tube assay, structurally intact and thus potentially infectious viral particles in environmental samples.

Application of enteric viruses for fecal pollution source tracking in environmental waters

Microbial source tracking (MST) tools are used to identify sources of fecal pollution for accurately assessing public health risk and implementing best management practices (BMPs). This review focuses on the potential of enteric viruses for MST applications. Following host infection, enteric viruses replicate and are excreted in high numbers in the hosts' feces and urine. Due to the specificity in host infection, enteric viruses have been considered one of the most accurate library-independent culture-independent MST tools. In an assessment of molecular viral assays based on sensitivity, specificity and the density of the target virus in fecal-impacted samples, human adenovirus and human polyomavirus were found to be the most promising human-specific viral markers. However, more research is needed to identify promising viral markers for livestock because of cross-reactions that were observed among livestock species or the limited number of samples tested for specificity. Other viral indicators of fecal origin, F+ RNA coliphage and pepper mild mottle virus, have also been proposed as potential targets for developing MST markers. Enhancing the utility of enteric viruses for MST applications through next generation sequencing (NGS) and virus concentration technology is discussed in the latter part of this review. The massive sequence databases generated by shotgun and gene-targeted metagenomics enable more efficient and reliable design of MST assays. Finally, recent studies revealed that alternative virus concentration methodologies may be more cost-effective than standard technologies such as 1MDS; however, improvements in the recovery efficiency and consistency are still needed. Overall, developments in metagenomic information combined with efficient concentration methodologies, as well as high host-specificity, make enteric viruses a promising tool in MST applications.

A potentially fatal mix of herpes in zoos

Pathogens often have a limited host range, but some can opportunistically jump to new species. Anthropogenic activities that mix reservoir species with novel, hence susceptible, species can provide opportunities for pathogens to spread beyond their normal host range. Furthermore, rapid evolution can produce new pathogens by mechanisms such as genetic recombination. Zoos unintentionally provide pathogens with a high diversity of species from different continents and habitats assembled within a confined space. Institutions alert to the problem of pathogen spread to unexpected hosts can monitor the emergence of pathogens and take preventative measures. However, asymptomatic infections can result in the causative pathogens remaining undetected in their reservoir host. Furthermore, pathogen spread to unexpected hosts may remain undiagnosed if the outcome of infection is limited, as in the case of compromised fertility, or if more severe outcomes are restricted to less charismatic species that prompt only limited investigation. We illustrate this problem here with a recombinant zebra herpesvirus infecting charismatic species including zoo polar bears over at least four years. The virus may cause fatal encephalitis and infects at least five mammalian orders, apparently without requiring direct contact with infected animals.