Search Results (65)

A duck adenovirus type 3 strain, SD2019, was isolated from sick Muscovy ducks in our laboratory in 2019. To study the biological properties of the virus, an infectious clone of the SD2019 strain was successfully established. The plasmid containing the whole genome of DAdV-3 was digested with Pac I and the linearized DNAs were electortransfected into LMH cells; the cells showed cytopathic effects (CPEs) at 96 h post transfection and the rescued virus (rSD2019) was identified by PCR and indirect immunofluorescence assays (IFAs). The biological characteristics of strain rSD2019 were studied in vitro and in vivo and the results show that rSD2019 grew to similar titers as compared with the wild-type SD2019 strain in LMH cells, as well as showing similar replication and virulence in Muscovy ducks. The establishment of a reliable reverse genetics system for DAdV-3 provides a foundation for future studies of DAdV-3. Full article

México is the world’s leading producer of avocado, with 2,540,715 tons in the last year. Trametes spp. are macromycete fungi that rot wood. In 2022, in the state of Michoacán, México, sporomas of Trametes sp. were found in the trunks of avocado trees (Persea americana var. Hass) of 10 years old and older. The trees showed disease symptoms including yellowing of leaves, widespread defoliation, and wilting. It was observed that 10% of the infected trees were felled after heavy rains. In the place where the fungus settled, abundant cream-colored and cottony mycelium developed, causing “white rot”. The incidence of the disease in the sampled orchards was 60% in the tree population per hectare with 350 trees. The symptomatic trees studied were randomly selected from seven orchards. The collected fungal samples show typical structures corresponding to Trametes sp., including large sporomas, a pileus with a surface of concentric zones of various ocher tones, and a porous hymenium. The samples showed a 99% match with the species Trametes hirsuta. Laboratory bioassays of inoculation in fresh wood segments of avocado formed typical sporomas of the pathogen. Finally, the fungus was recovered and reisolated in vitro in PDA, and its identity was confirmed through the morphological characteristics and molecular tests. To the best of our knowledge, this article reports for the first time that P. americana cv. Hass and Mendez are new hosts for T. hirsuta. Therefore, the environmental and horticultural management conditions that favor the proliferation of T. hirsuta must be investigated. Full article

Fowl adenoviruses (FAdVs) are important emerging pathogens affecting the poultry industry in Egypt as they are the primary etiology of inclusion body hepatitis–hydropericardium syndrome (IBH-HPS) associated with severe economic losses. This study aims to identify the circulating FAdVs from cases of IBH-HPS in 5 Egyptian provinces during the period from October 2020 through September 2022. Out of the 210 examined flocks, liver samples from 66 flocks were positive for FAdVs (31.4%) using conventional polymerase chain reaction targeting loop 1 of the major hexon gene, with varying rates of mortality (1% to 14%). In the positive samples detected during the study, the histopathological examination revealed pathognomonic lesions of FAdVs, including basophilic and eosinophilic intra-nuclear inclusion bodies (INIBs). The percentage of FAdV positivity increased with the flock age; from samples collected at ages 1 to10, 11 to 20, 21 to 30, and >30 days of age, 10% (5/50), 25.6% (11/43), 34.3% (23/67), and 54% (27/50) were found positive for FAdVs, respectively. Notably, the positivity percentages among the flocks reared in cages were higher than for those reared in the deep litter system of housing. The gene sequencing and phylogenetic analysis of 19 strains revealed clustering into FAdV species D serotype 2/11, demonstrating that serotype 2/11 is most prevalent in the targeted Egyptian provinces during the period of the study. Several point mutations in the sequenced region among different strains were reported. These findings underscore the prevalence of FAdV and provide a basis for further research on circulating strains to develop effective control strategies. Full article

Human enteric adenoviruses (HAdV-F40/41) play a crucial role as causative agents of acute gastroenteritis (AGE), particularly affecting children in low-and middle-income countries. This study investigated the prevalence, genetic diversity, and molecular characteristics of HAdV-F40/41 in AGE cases reported in Brazil from 2021 to 2023, a period after the COVID-19 pandemic. A total of 1980 stool samples collected from medically attended AGE patients from nine states were analyzed by TaqMan-based qPCR. Overall, HAdV was detected in 16.6% (n = 328/1980) of cases, with the highest prevalence observed in children under five years of age. The positive HAdV samples were genotyped through partial sequencing of the hexon and/or fiber genes followed by phylogenetic analysis. Enteric HAdVs (HAdV-F40/41) were detected in 3.2% (n = 63/1980) of samples, with HAdV-F41 (44.1%) being the most common genotype. Among the non-enteric types, HAdV-C (29.4%) was the most prevalent, followed by HAdV-B (13.2%), HAdV-A (10.3%), and HAdV-D (2.9%). Phylogenetic analysis of the hexon (HVR1–HVR6) and fiber (Shaft) gene regions identified two major clusters, H-GTC1 and F-GTC2, showing close genetic relationships with global strains. HAdV-F40/41 demonstrated significantly higher viral loads compared to non-enteric HAdVs. These findings highlight the importance of continued surveillance of HAdV-F to better understand its role in AGE cases and support public health strategies, including potential vaccine development. Full article

Fowl adenovirus (FAdV) belongs to the Aviadenovirus genus within the Adenoviridae family. FAdVs are widely distributed and associated with various diseases in poultry, including adenoviral gizzard erosion (AGE), hepatitis-hydropericardium syndrome (HHS), and inclusion body hepatitis (IBH). In this study, we developed a multiplex conventional PCR for simultaneously detecting FAdV-4, -8b, and -11 by targeting the hexon gene. The multiplex PCR was optimized for primer concentrations and thermocycling conditions. The optimal primer concentration combination was set at 0.125 μM for FAdV-4, -8b, and 0.25 μM for FAdV-11. Under these conditions, the limit of detection (LOD) was 10³ copies/μL of plasmid standards for FAdV-4, -8b, and -11. These results demonstrated that the developed multiplex PCR method exhibits high specificity and sensitivity, with no observed cross-reactivity among these serotypes or with other poultry viruses. Therefore, this multiplex PCR will be an effective tool for accurate serotyping of FAdV-4, -8b, and -11, enabling more precise identification and differentiation of these three serotypes. Full article

Adenovirus (AdV) infection has been rarely documented in cats and other felids. Partial sequences of the hexon and fiber genes of a Hungarian feline adenovirus isolate (FeAdV isolate) showed a close relationship to human AdV (HAdV) type C1. Further molecular and biological characterization is reported here. Whole-genome sequencing revealed two silent mutations in the genome of the FeAdV isolate compared to a HAdV-C1 reference strain (at positions 14,096 and 15,082). Competitive antibody binding to the Coxsackie–adenovirus receptor and α_vβ₃ and α_vβ₅ integrin coreceptors inhibited the binding of the FeAdV isolate in different cell lines, but residual infections suggested alternative entry routes. The FeAdV isolate was found to be more sensitive to heat, low pH and detergents, but more resistant to alkaline and free chlorine treatments, as well as to ribavirin, stavudine and cidofovir treatments, than other human AdV types. We observed a suppression of IL-10 and TGF-β1 production during the entire course of viral replication. This immunomodulation may restore intratumoral immunity; thus, the FeAdV isolate could serve as an alternative oncolytic vector. Collectively, our results support that the Hungarian FeAdV isolate is a variant of common HAdV-C1. The cohabitation of cats with humans might result in reverse zoonotic infection. Felids appear to be susceptible to persistent and productive adenovirus infection, but further studies are needed to better understand the clinical and epidemiological implications. Full article

Canine coronavirus (CCoV), canine respiratory coronavirus (CRCoV), canine adenovirus type 2 (CAV-2), and canine norovirus (CNV) are important pathogens for canine viral gastrointestinal and respiratory diseases. Especially, co-infections with these viruses exacerbate the damages of diseases. In this study, four pairs of primers and probes were designed to specifically amplify the conserved regions of the CCoV M gene, CRCoV N gene, CAV-2 hexon gene, and CNV RdRp gene. After optimizing different reaction conditions, a quadruplex RT-qPCR was established for the detection of CCoV, CRCoV, CAV-2, and CNV. The specificity, sensitivity, and repeatability of the established assay were evaluated. Then, the assay was used to test 1688 clinical samples from pet hospitals in Guangxi province of China during 2022–2024 to validate its clinical applicability. In addition, these samples were also assessed using the reported reference RT-qPCR assays, and the agreements between the developed and reference assays were determined. The results indicated that the quadruplex RT-qPCR could specifically test only CCoV, CRCoV, CAV-2, and CNV, without cross-reaction with other canine viruses. The assay had high sensitivity with limits of detection (LODs) of 1.0 × 10² copies/reaction for CCoV, CRCoV, CAV-2, and CNV. The repeatability was excellent, with intra-assay variability of 0.19–1.31% and inter-assay variability of 0.10–0.88%. The positivity rates of CCoV, CRCoV, CAV-2, and CNV using the developed assay were 8.59% (145/1688), 8.65% (146/1688), 2.84% (48/1688), and 1.30% (22/1688), respectively, while the positivity rates using the reference assays were 8.47% (143/1688), 8.53% (144/1688), 2.78% (47/1688), and 1.24% (21/1688), respectively, with agreements of more than 99.53% between two methods. In conclusion, a quadruplex RT-qPCR with high sensitivity, specificity, and repeatability was developed for rapid, and accurate detection of CCoV, CRCoV, CAV-2, and CNV. Full article

Certain species D human adenoviruses (HAdV-D19, -D37, and -D64) are causative agents of epidemic keratoconjunctivitis. HAdV-D37 has previously been shown to bind CD46 (membrane cofactor protein) and sialic acid as adhesion receptors. HAdV-D64 is genetically highly similar to HAdV-D37, with an identical fiber protein sequence, but differs substantially in its penton base and hexon proteins, two other major capsid components, due to genetic recombination. Here, we demonstrate that, like HAdV-D37, HAdV-D64 virions bind directly to CD46 and that CD46 and sialic acid also function as receptors for HAdV-D64 on multiple cell types. Expression of CD46 on CD46-negative cells conferred susceptibility to HAdV-D64 entry. Specifically blocking HAdV-D64 binding to CD46 on the host cell surface strongly inhibits viral entry and gene delivery into multiple cell lines that represent target tissues. We show that CD46 is expressed on human conjunctival epithelial cells and directly binds to the HAdV-D64 virion. Our results suggest that HAdV-D64 may be used to deliver genes to target conjunctival cells and that interrupting HAdV-D64 entry through its interaction with CD46 may prevent or lessen adenovirus-associated ocular disease. Full article

Duck adenovirus Type 3 (DAdV-3) severely affects the health of ducks; however, its pathogenicity in chickens remains unknown. The objectives of this study were to evaluate the pathogenicity and major pathological changes caused by DAdV-3 in chickens. Viral DNA was extracted from the liver of the Muscovy duck, and the fiber-2 and hexon fragments of DAdV-3 were amplified through polymerase chain reaction (PCR). The evolutionary tree revealed that the isolated virus belonged to DAdV-3, and it was named HE-AN-2022. The mortality rate of chicks that received inoculation with DAdV-3 subcutaneously via the neck was 100%, while the mortality rate for eye–nose drop inoculation was correlated with the numbers of infection, with 26.7% of chicks dying as a result of exposure to multiple infections. The main symptoms exhibited prior to death were hepatitis–hydropericardium syndrome (HHS), ulceration of the glandular stomach, and a swollen bursa with petechial hemorrhages. A histopathological examination revealed swelling, necrosis, lymphocyte infiltration, and basophilic inclusion bodies in multiple organs. Meanwhile, the results of quantitative real-time PCR (qPCR) demonstrated that DAdV-3 could affect most of the organs in chickens, with the gizzard, glandular stomach, bursa, spleen, and liver being the most susceptible to infection. The surviving chicks had extremely high antibody levels. After the chickens were infected with DAdV-3 derived from Muscovy ducks, no amino acid mutation was observed in the major mutation regions of the virus, which were ORF19B, ORF66, and ORF67. On the basis of our findings, we concluded that DAdV-3 infection is possible in chickens, and that it causes classic HHS with ulceration of the glandular stomach and a swollen bursa with petechial hemorrhages, leading to high mortality in chickens. The major variation domains did not change in Muscovy ducks or in chickens after infection. This is the first study to report DAdV-3 in chickens, providing a new basis for preventing and controlling this virus. Full article

Human adenovirus (HAdV) F40/41 is an important pathogen in pediatric acute gastroenteritis cases. However, the diversity of study designs and diagnostic methods often leads to misinterpretations of their impact. Our study explored the genetic diversity of HAdV-F40/41 in Brazil using a specific qPCR assay for HAdV species F, combined with a phylogenetic analysis of the partial hexon and fiber genes. Our results demonstrated that HAdV-F41 strains predominated and exhibited higher diversity than HAdV-F40 strains. Based on the hexon gene, Brazilian HAdV-F41 strains were grouped into two genome type clusters (GTC), further divided into subclusters, with most strains clusteringto GTC2. The partial shaft region of the fiber gene exhibited higher conservation among HAdV-F41. The specific qPCR assay for HAdV species F identified HAdV-F in an additional 31.5% (34/108) of previously uncharacterized HAdV-positive samples detected using a non-specific HAdV qPCR assay. Both assays strongly correlated in detecting HAdV-F, and the specific qPCR assay for enteric types can enhance HAdV surveillance, especially when sequencing is not possible. Our study provides novel insights regarding the genetic diversity of HAdV-F species in Brazil. Full article

There are varying data concerning the effect of prior anti-vector immunity on the T-cell response induced by immunisation with an identical vectored vaccine containing a heterologous antigen insert. To determine whether prior exposure to ChAdOx1-SARS-CoV2 immunisation (Vaxzevria^®) impacts magnitudes of antigen-specific T-cell responses elicited by subsequent administration of the same viral vector (encoding HBV antigens, ChAdOx1-HBV), healthy volunteers that had received Vaxzevria^® (n = 15) or the Pfizer or Moderna mRNA COVID-19 vaccine (n = 11) between 10 and 18 weeks prior were recruited to receive a single intramuscular injection of ChAdOx1-HBV. Anti-ChAdOx1-neutralising antibody titers were determined, and vector or insert-specific T-cell responses were measured by a gamma-interferon ELISpot and intracellular cytokine staining (ICS) assay using multiparameter flow cytometry. Participants were followed for three months after the ChAdOx1-HBV injection, which was well-tolerated, and no dropouts occurred. The baseline ChAdOx1 neutralisation titers were higher in the Vaxzevria^® cohort (median of 848) than in the mRNA cohort (median of 25). T-cell responses to HBV antigens, measured by ELISpot, were higher on day 28 in the mRNA group (p = 0.013) but were similar between groups on day 84 (p = 0.441). By ICS, these differences persisted at the last time point. There was no clear correlation between the baseline responses to the adenoviral hexon and the subsequent ELISpot responses. As vaccination within 3 months using the same viral vector backbone affected the insert-specific T-cell responses, a greater interval after prior adenoviral immunisation using heterologous antigens may be warranted in settings in which these cells play critical roles. Full article

Recombination events in human adenovirus (HAdV) have led to some new highly pathogenic or infectious types. It is vital to monitor recombinant HAdVs, especially in children with acute respiratory tract infections (ARIs). In the retrospective study, HAdV positive specimens were collected from pediatric patients with ARIs during 2015 to 2021, then typed by sequence analysis of the penton base, hexon and fiber gene sequence. For those with inconsistent typing results, a modified method with species-specific primer sets of a fiber gene sequence was developed to distinguish co-infections of different types from recombinant HAdV infections. Then, plaque assays combined with meta-genomic next-generation sequencing (mNGS) were used to reveal the HAdV genomic characteristics. There were 466 cases positive for HAdV DNA (2.89%, 466/16,097) and 350 (75.11%, 350/466) successfully typed with the most prevalent types HAdV-B3 (56.57%, 198/350) and HAdV-B7 (32.00%, 112/350), followed by HAdV-C1 (6.00%, 21/350). Among 35 cases (7.51%, 35/466) with inconsistent typing results, nine cases were confirmed as co-infections by different types of HAdVs, and 26 cases as recombinant HAdVs in six genetic patterns primarily clustered to species C (25 cases) in pattern 1–5, or species D (1 case) in pattern 6. The novel recombinant HAdV of species D was identified with multiple recombinant events among HAdV-D53, HAdV-D64, and HAdV-D8, and officially named as HAdV-D115. High-frequency recombination of HAdVs in six genetic recombination patterns were identified among children with ARIs in Beijing. Specifically, there is a novel Adenovirus D human/CHN/S8130/2023/115[P22H8F8] designed as HAdV D115. Full article

Fowl aviadenovirus (FAdV) is a member of the Aviadenovirus genus within the Adenoviridae family. FAdVs are divided into five species based on genomic differences: Fowl aviadenovirus A to Fowl aviadenovirus E (FAdV-A to FAdV-E). They are classified into twelve serotypes (FAdV-1 to FAdV-8a and FAdV-8b to FAdV-11) through cross-neutralization tests. FAdVs are mainly associated with hepatitis hydropericardium syndrome (HHS), adenoviral gizzard erosion (AGE), and inclusion body hepatitis (IBH). The serotypes commonly involved in IBH are FAdV-2, FAdV-11, FAdV-8a, and FAdV-8b. IBH causes significant economic losses in the poultry industry, mainly due to high mortality, reduced productivity, and immunosuppression. This is the first case report on IBH in Chile caused—according to post-mortem findings, molecular analysis, sequencing, and phylogenetic analysis—by FAdV-11. Since the serotype had not previously been reported in Chile, continued monitoring of IBH cases is required to determine the serotype of the circulating FAdVs and adapt preventative vaccination programs. Full article

Fowl adenoviruses (FAdVs, species FAdV-A/-E) are responsible for several clinical syndromes reported with increasing frequency in poultry farms in the last decades. In the present study, a phylodynamic analysis was performed on a group of FAdV-D Hexon sequences with adequate available metadata. The obtained results demonstrated the long-term circulation of this species, at least several decades before the first identification of the disease. After a period of progressive increase, the viral population showed a high-level circulation from approximately the 1960s to the beginning of the new millennium, mirroring the expansion of intensive poultry production and animal trade. At the same time, strain migration occurred mainly from Europe to other continents, although other among-continent connections were estimated. Thereafter, the viral population declined progressively, likely due to the improved control measures, potentially including the development and application of FAdV vaccines. An increase in the viral evolutionary rate featured this phase. A role of vaccine-induced immunity in shaping viral evolution could thus be hypothesized. Accordingly, several sites of the Hexon, especially those targeted by the host response were proven under a significant pervasive or episodic diversifying selection. The present study results demonstrate the role of intensive poultry production and market globalization in the rise of FAdV. The applied control strategies, on the other hand, were effective in limiting viral circulation and shaping its evolution. Full article

Fowl adenovirus-induced hepatitis–pericardial effusion syndrome outbreaks have been increasingly reported in China since 2015, resulting in substantial economic losses to the poultry industry. The genetic diversity of indigenous chicken results in different immune traits, affecting the evolution of these viruses. Although the molecular epidemiology of fowl adenovirus serotype 4 (FAdV-4) has been well studied in commercial broiler and layer chickens, the prevalence and genetic characteristics of FAdV-4 in indigenous chickens remain largely unknown. In this study, samples were collected from six indigenous chicken breeds in Yunnan province, China. FAdV-positive samples were identified in five of the six indigenous chicken populations via PCR and 10 isolates were obtained. All FAdVs belonged to serotype FAdV-4 and species FAdV-C. The hexon, fiber, and penton gene sequence comparison analysis demonstrated that the prevalence of FAdV-4 isolates in these chickens might have originated from other provinces that exported chicks and poultry products to Yunnan province. Moreover, several distinct amino acid mutations were firstly identified in the major structural proteins. Our findings highlighted the need to decrease inter-regional movements of live poultry to protect indigenous chicken genetic resources and that the immune traits of these indigenous chickens might result in new mutations of FAdV-4 strains. Full article