Susceptibility of herons (family: Ardeidae) to clade 2.3.2.1 H5N1 subtype high pathogenicity avian influenza virus.

The pathogenicity of the H5 subtype high pathogenicity avian influenza viruses (HPAIVs) in Ardeidae bird species has not been investigated yet, despite the increasing infections reported. Therefore, the present study aimed to examine the susceptibility of the Ardeidae species, which had already been reported to be susceptible to HPAIVs, to a clade 2.3.2.1 H5N1 HPAIV. Juvenile herons (four grey herons, one intermediate egret, two little egrets, and three black-crowned night herons) were intranasally inoculated with 106 50% egg infectious dose of the virus and observed for 10 days. Two of the four grey herons showed lethargy and conjunctivitis; among them, one died at 6 days post-inoculation (dpi). The viruses were transmitted to the other two cohoused naïve grey herons. Some little egrets and black-crowned night herons showing neurological disorders died at 4-5 dpi; these birds mainly shed the virus via the oral route. The viruses predominantly replicated in the brains of birds that died of infection. Seroconversion was observed in most surviving birds, except some black-crowned night herons. These results demonstrate that most Ardeidae species are susceptible to H5 HPAIVs, sometimes with lethal effects. Herons are mostly colonial and often share habitats with Anseriformes, natural hosts of influenza A viruses; therefore, the risks of cluster infection and contribution to viral dissemination should be continuously evaluated. RESEARCH HIGHLIGHTSClade 2.3.2.1 H5N1 HPAIV causes lethal infections in Ardeidae sp.Viruses are transmitted among grey herons.Some herons with HPAIV showed conjunctivitis or neurological symptoms.HPAIV systemically replicated in herons tissues.

Pathogenicity of clade 2.3.2.1 H5N1 highly pathogenic avian influenza virus in American kestrel (Falco sparverius).

Birds of prey, including endangered species, have been infected with H5 highly pathogenic avian influenza viruses (HPAIVs) in several countries. In this present study, we assessed the pathogenicity of the clade 2.3.2.1 H5N1 HPAIV in American kestrels (Falco sparverius) with a view to preventing future outbreaks in raptors. The kestrels were intranasally inoculated with the virus or fed the meat of chicks that had died from viral infection. Kestrels in both groups initially had reduced food intake, showed clinical signs such as depression and neurologic manifestations, and succumbed to the infection within 6 days. The kestrels primarily shed the virus orally from 1 day post-inoculation until death, with an average titre of 104.5-5.7 EID50/ml, which is comparable to the inoculum titre. The viruses replicated in almost all tested tissues; notably, the feather calamuses also contained infectious virions and/or viral genes. Pancreatic lesions were present in several infected birds, as shown in previous cases of HPAIV infection in raptors. These results indicate that kestrels are highly susceptible to infection by clade 2.3.2.1 H5 HPAIVs, which readily occurs through the consumption of infected bird carcasses. Early detection and removal of HPAIV infected carcasses in the field is essential for preventing outbreaks in raptors. RESEARCH HIGHLIGHTS Clade 2.3.2.1 H5 HPAIV caused lethal infection in American kestrels. Kestrels with the HPAIV showed neurologic signs and eye disorders. The HPAIV replicated in systemic tissues of kestrels, and was orally shed. The HPAIV was recovered from feather calamus of kestrels.

The cholesterol, fatty acid and triglyceride synthesis pathways regulated by site 1 protease (S1P) are required for efficient replication of severe fever with thrombocytopenia syndrome virus.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by the SFTS virus (SFTSV), which has a high mortality rate. Currently, no licensed vaccines or therapeutic agents have been approved for use against SFTSV infection. Here, we report that the cholesterol, fatty acid, and triglyceride synthesis pathways regulated by S1P is involved in SFTSV replication, using CHO-K1 cell line (SRD-12B) that is deficient in site 1 protease (S1P) enzymatic activity, PF-429242, a small compound targeting S1P enzymatic activity, and Fenofibrate and Lovastatin, which inhibit triglyceride and cholesterol synthesis, respectively. These results enhance our understanding of the SFTSV replication mechanism and may contribute to the development of novel therapies for SFTSV infection.

A phantom study investigating the relationship between ground-glass opacity visibility and physical detectability index in low-dose chest computed tomography.

In this study, the relationship between ground-glass opacity (GGO) visibility and physical detectability index in low-dose computed tomography (LDCT) for lung cancer screening was investigated. An anthropomorphic chest phantom that included synthetic GGOs with CT numbers of -630 Hounsfield units (HU; high attenuation GGO: HGGO) and -800 HU (low attenuation GGO: LGGO), and three phantoms for physical measurements were employed. The phantoms were scanned using 12 CT systems located in 11 screening centers in Japan. The slice thicknesses and CT dose indices (CTDI(vol)) varied over 1.0-5.0 mm and 0.85-3.30 mGy, respectively, and several reconstruction kernels were used. Physical detectability index values were calculated from measurements of resolution, noise, and slice thickness properties for all image sets. Five radiologists and one thoracic surgeon, blind to one another's observations, evaluated GGO visibility using a five-point scoring system. The physical detectability index correlated reasonably well with the GGO visibility (R² = 0.709, p < 0.01 for 6 mm HGGO and R² = 0.646, p < 0.01 for 10 mm LGGO), and was nearly proportional to the CTDI(vol). Consequently, the CTDI(vol) also correlated reasonably well with the GGO visibility (R² = 0.701, p < 0.01 for 6 mm HGGO and R² = 0.680, p < 0.01 for 10 mm LGGO). As a result, the CTDI(vol) was nearly dominant in the GGO visibility for image sets with different reconstruction kernels and slice thicknesses, used in this study.

Susceptibility of Synanthropic Rodents (Mus musculus, Rattus norvegicus and Rattus rattus) to H5N1 Subtype High Pathogenicity Avian Influenza Viruses.

Synanthropic wild rodents associated with agricultural operations may represent a risk path for transmission of high pathogenicity avian influenza viruses (HPAIVs) from wild birds to poultry birds. However, their susceptibility to HPAIVs remains unclear. In the present study, house mice (Mus musculus), brown rats (Rattus norvegicus), and black rats (Rattus rattus) were experimentally exposed to H5N1 subtype HPAIVs to evaluate their vulnerability to infection. After intranasal inoculation with HA clade 2.2 and 2.3.2.1 H5N1 subtype HPAIVs, wild rodents did not show any clinical signs and survived for 10- and 12-day observation periods. Viruses were isolated from oral swabs for several days after inoculation, while little or no virus was detected in their feces or rectal swabs. In euthanized animals at 3 days post-inoculation, HPAIVs were primarily detected in respiratory tract tissues such as the nasal turbinates, trachea, and lungs. Serum HI antibodies were detected in HA clade 2.2 HPAIV-inoculated rodents. These results strongly suggest that synanthropic wild rodents are susceptible to infection of avian-origin H5N1 subtype HPAIVs and contribute to the virus ecosystem as replication-competent hosts. Detection of infectious viruses in oral swabs indicates that wild rodents exposed to HPAIVs could contaminate food, water, and the environment in poultry houses and play roles in the introduction and spread of HPAIVs in farms.

Alkoxyl- and carbon-centered radicals as primary agents for degrading non-phenolic lignin-substructure model compounds.

Lignin degradation by white-rot fungi proceeds via free radical reaction catalyzed by oxidative enzymes and metabolites. Basidiomycetes called selective white-rot fungi degrade both phenolic and non-phenolic lignin substructures without penetration of extracellular enzymes into the cell wall. Extracellular lipid peroxidation has been proposed as a possible ligninolytic mechanism, and radical species degrading the recalcitrant non-phenolic lignin substructures have been discussed. Reactions between the non-phenolic lignin model compounds and radicals produced from azo compounds in air have previously been analysed, and peroxyl radical (PR) is postulated to be responsible for lignin degradation (Kapich et al., FEBS Lett., 1999, 461, 115-119). However, because the thermolysis of azo compounds in air generates both a carbon-centred radical (CR) and a peroxyl radical (PR), we re-examined the reactivity of the three radicals alkoxyl radical (AR), CR and PR towards non-phenolic monomeric and dimeric lignin model compounds. The dimeric lignin model compound is degraded by CR produced by reaction of 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH), which under N(2) atmosphere cleaves the α-ß bond in 1-(4-ethoxy-3-methoxyphenyl)-2-(2-methoxyphenoxy)-1,3-propanediol to yield 4-ethoxy-3-methoxybenzaldehyde. However, it is not degraded by the PR produced by reaction of Ce(4+)/tert-BuOOH. In addition, it is degraded by AR produced by reaction of Ti(3+)/tert-BuOOH. PR and AR are generated in the presence and absence of veratryl alcohol, respectively. Rapid-flow ESR analysis of the radical species demonstrates that AR but not PR reacts with the lignin model compound. Thus, AR and CR are primary agents for the degradation of non-phenolic lignin substructures.

Molecular epidemiological characterization of poultry red mite, Dermanyssus gallinae, in Japan.

Dermanyssus gallinae, the poultry red mite, is an obligatory blood-sucking ectoparasite. The genetic diversity of D. gallinae has been examined in some countries, but so far not in Asian countries. Here, we sequenced a part of the mitochondrial cytochrome oxidase subunit I (COI) and16S rRNA genes and nuclear internal transcribed spacers (ITS) region in 239 mite samples collected from 40 prefectures throughout Japan. The COI and 16S rRNA nucleotide sequences were classified into 28 and 26 haplotypes, respectively. In phylogenetic trees, the haplotypes clustered into 2 haplogroups corresponding to haplogroups A and B, which were previously reported. Haplogroups A and B were further subdivided into sub-haplogroups AJ1 and AJ2, and BJ1 and BJ2, respectively. In both trees, the sequences of haplotypes in AJ1 and BJ2 were relatively distant from those reported in other countries, while some sequences in AJ2 and BJ1 were identical to those in Europe. In addition, the ITS sequences were classified into two sequences, and both sequences were closely related to the sequences found in European countries. These findings indicate a possibility of international oversea transmission of D. gallinae.

Molecular detection of avian pathogens in poultry red mite (Dermanyssus gallinae) collected in chicken farms.

Poultry red mite (PRM, Dermanyssus gallinae) is a blood-sucking ectoparasite as well as a possible vector of several avian pathogens. In this study, to define the role of PRM in the prevalence of avian infectious agents, we used polymerase chain reaction (PCR) to check for the presence of seven pathogens: Avipox virus (APV), Fowl Adenovirus (FAdV), Marek's disease virus (MDV), Erysipelothrix rhusiopathiae (ER), Salmonella enterica (SE), Mycoplasma synoviae (MS) and Mycoplasma gallisepticum (MG). A total of 159 PRM samples collected between 2004 and 2012 from 142 chicken farms in 38 prefectures in Japan were examined. APV DNA was detected in 22 samples (13.8%), 19 of which were wild-type APV. 16S ribosomal RNA (16S rRNA) of MS was detected in 15 samples (9.4%), and the mgc2 gene of MG was detected in 2 samples (1.3%). Eight of 15 MS 16S rRNA sequences differed from the vaccine sequence, indicating they were wild-type strains, while both of the MG mgc2 gene sequences detected were identical to the vaccine sequences. Of these avian pathogen-positive mite samples, three were positive for both wild-types of APV and MS. On the other hand, the DNAs of ER, SE, FAdV and MDV were not detected in any samples. These findings indicated that PRM can harbor the wild-type pathogens and might play a role as a vector in spreading these diseases in farms.

Pathogenicity of an H5N1 highly pathogenic avian influenza virus isolated in the 2010-2011 winter in Japan to mandarin ducks.

Widespread outbreaks of highly pathogenic avian influenza (HPAI) caused by H5N1 viruses occurred in wild birds in Japan from 2010-2011. Forty out of 63 deceased wild birds belonged to the order Anseriformes, and mandarin duck was one of the dominant species. To estimate the risk of mandarin ducks as a source of virus infection in the environment, we examined the pathogenicity of a causal H5N1 HPAI virus to mandarin ducks. About half of the mandarin ducks died by inoculation with 10(7.0)TCID50 of A/mandarin duck/Miyazaki/22M807-1/2011 (H5N1). Viruses were mainly recovered from the trachea of the ducks sacrificed at three days post inoculation (d.p.i.). Viruses were recovered from the laryngopharyngeal swabs of the observation group until 5 d.p.i. In ducks that died at the late phase of infection, viruses were detected in the systemic organs, such as lung, kidney and colon. Together, these results showed that the H5N1 HPAI viruses, which belonged to clade 2.3.2.1 and are mainly circulating in East Asia, were lethal to mandarin ducks, indicating that mandarin ducks have the potential to disseminate the virus to other bird species. Therefore, wild birds should be kept out of poultry farms to prevent HPAI outbreaks in the future.

The pathogenicity and host immune response associated with H5N1 highly pathogenic avian influenza virus in quail.

Quail, like chickens, are susceptible to H5N1 subtype highly pathogenic avian influenza virus (HPAIV). Both birds experience high mortality, but quail usually survive a few more days than chicken. To understand why, we monitored quail and chickens after inoculation with 10(6) fifty-percent egg infectious doses of HPAIV A/whooper swan/Aomori/1/2008 (H5N1). The clinical course initiated as depression at 48 hr post inoculation (h.p.i.) in quail and at 36 h.p.i. in chicken, and all infected birds died. Mean death time of quail (91 hr) was significantly longer than that of chicken (66 hr). The virus titers of most tissue samples collected before death were not significantly different. At 24 h.p.i., interferon gamma (IFN-γ) mRNA expression in peripheral blood mononuclear cells (PBMC) was up-regulated in the quail but down-regulated in the chicken, although TLR-7 and seven other cytokines showed no significant differences between quail and chicken. The viral load in quail PBMC was significantly lower than that in chickens. These results suggest that the induction of IFN-γ after HPAIV infection in quail is related to lower titer of HPAIV. In conclusion, the different clinical courses observed between quail and chicken infected with H5N1 HPAIV might be caused by different IFN-γ responses against the HPAIV infection.