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1.
J Pain Symptom Manage ; 67(2): 157-166, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37944624

ABSTRACT

CONTEXT: Physical symptoms such as pain and cancer-related fatigue limit physical function and activities of daily living among patients with terminal cancer, which can lead to a decline in quality of life. Therefore, comprehensive functional impairments should be evaluated to determine the progression of the disease and the effectiveness of palliative treatment. OBJECTIVE: To validate the psychometric properties of the Japanese version of the Edmonton Functional Assessment Tool 2 (EFAT2-J). METHODS: We developed a Japanese version of the EFAT-2 in accordance with international guidelines. To verify the reliability and validity of the EFAT2-J, patients were evaluated by a physiotherapist and a nurse separately, and correlations with existing evaluation scales for physical function, physical symptoms, and quality of life were analyzed, respectively. The significance level was set at 5%. RESULTS: Twenty patients participated in the reliability measurement. The average EFAT2-J scores were 7.95 ± 4.12 for physical therapists and 7.20 ± 4.23 for nurses, and the intraclass correlation coefficient was 0.95. The weighted kappa coefficient (κ) for each item was 0.57-1.00. Fifty-five patients participated in the validity measurement. The EFAT2-J showed significant correlations with Eastern Cooperative Oncology Group Performance Status and the Karnofsky Performance Scale, Barthel Index, and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 15-Palliative Care sub-item "physical function." CONCLUSION: These results indicate that the EFAT2-J has robust psychometric properties and is useful for evaluating physical function in patients with terminal cancer, and thus may be an acceptable clinical instrument in research and practice.


Subject(s)
Neoplasms , Quality of Life , Humans , Psychometrics/methods , Reproducibility of Results , Activities of Daily Living , Japan , Neoplasms/diagnosis , Neoplasms/therapy , Surveys and Questionnaires
2.
Parasit Vectors ; 14(1): 494, 2021 Sep 26.
Article in English | MEDLINE | ID: mdl-34565449

ABSTRACT

BACKGROUND: In Hokkaido, northern island of Japan, at least seven cases of falciparum malaria were reported by 1951. A survey conducted at that time was unsuccessful in implicating any mosquito species as the possible vector. Although active anopheline mosquito surveillance continued until the middle of the 1980s, there is very limited information on their current status and distribution in Japan. Therefore, this study is an update on the current status and distribution of anopheline mosquitoes in Hokkaido based on a 15-year entomological surveillance between 2001 and 2015. METHODS: A survey of mosquitoes was conducted at 22 sites in Hokkaido, Japan, from 2001 to 2015. Adult mosquitoes were collected from cowsheds, lakesides, shrubs, and habitats ranging from open grassland to coniferous forest using a Centers for Disease Control and Prevention (CDC) miniature light trap enhanced with dry ice, aspirators, and sweeping nets. Larvae were collected from lakes, ponds, swamps, stagnant and flowing rivers, and paddy fields. All specimens were morphologically identified and subjected to polymerase chain reaction (PCR)-based sequence analysis of the internal transcribed spacer 2 ( ITS2) region of rDNA. Phylogenetic trees were reconstructed using the neighbor-joining method with the Kimura 2-parameter model on MEGA X version 10.2.2. RESULTS: A total of 46 anopheline specimens were used for the phylogenetic analysis. During the survey, a new member of the Anopheles hyrcanus group, An. belenrae, was discovered in eastern Hokkaido in 2004. Anopheles belenrae has since then been consistently found and confirmed to inhabit only this area of Japan. Four members of the An. hyrcanus group, namely An. belenrae, An. engarensis, An. lesteri, and An. sineroides, have been found in Hokkaido. The results also suggest that An. sinensis, formerly a dominant species throughout Japan, has become a rarely found species, at least currently in Hokkaido. CONCLUSION: The updated distribution of anopheline mosquitoes in Hokkaido, Japan, showed considerable differences from that observed in previous surveys conducted from 1969 to 1984. In particular, areas where An. sinensis was previously distributed may have been greatly reduced in Hokkaido. The phylogenetic analysis revealed a novel An. hyrcanus group member identified as An. belenrae, described in South Korea in 2005. It is interesting that An. belenrae was confirmed to inhabit only eastern Hokkaido, Japan.


Subject(s)
Animal Distribution , Anopheles/physiology , Mosquito Vectors/physiology , Animals , Anopheles/classification , Anopheles/genetics , Ecosystem , Female , Japan , Male , Mosquito Vectors/classification , Mosquito Vectors/genetics , Phylogeny
3.
Jpn J Infect Dis ; 70(1): 38-44, 2017 Jan 24.
Article in English | MEDLINE | ID: mdl-27169949

ABSTRACT

There are three main innate immune mechanisms against viruses in mosquitoes. Infection with the flavivirus dengue virus is controlled by RNA interference (RNAi) and the JAK-STAT and Toll signaling pathways. This study showed that another flavivirus, Japanese encephalitis virus (JEV), did not invade the salivary glands of Aedes aegypti and that this may be a result of the innate immune resistance to the virus. Argonaute 2 (Ago2) plays a critical role in the RNAi pathway. To understand the mechanism of JEV resistance, we focused on Ago2 as a possible target of JEV. Here, we show that the expression of MyD88 (a mediator of Toll signaling) and Ago2 mRNAs was induced by JEV in the salivary glands of Ae. aegypti mosquitoes and that Ago2, JAK, and domeless (DOME) mRNAs were induced by JEV in the bodies of Ae. aegypti mosquitoes. Double-stranded (ds) Ago2 RNA enhanced JEV infection, and the virus was detected in salivary glands by immunofluorescence assay. In contrast, MyD88 dsRNA had no effect on JEV infection. These data suggest that Ago2 plays a crucial role in mediating the innate immune response of Ae. aegypti to JEV in a manner similar to that employed by dengue virus.


Subject(s)
Aedes/virology , Argonaute Proteins/metabolism , Encephalitis Virus, Japanese/growth & development , Encephalitis Virus, Japanese/immunology , Aedes/immunology , Animals , Argonaute Proteins/genetics , Female , Gene Expression Profiling , Immunity, Innate , Myeloid Differentiation Factor 88/genetics , Myeloid Differentiation Factor 88/metabolism , RNA Interference , Salivary Glands/pathology , Salivary Glands/virology
4.
J Med Entomol ; 52(2): 222-9, 2015 Mar.
Article in English | MEDLINE | ID: mdl-26336307

ABSTRACT

Superinfection exclusion is generally defined as a phenomenon in which a pre-existing viral infection prevents a secondary viral infection; this has also been observed in infections with mosquito-borne viruses. In this study, we examined the superinfection exclusion of the vertebrate-infecting flaviviruses, Japanese encephalitis virus (JEV) and dengue virus (DENV), by stable and persistent infection with an insect-specific flavivirus, Culex flavivirus (CxFV), in a Culex tritaeniorhynchus Giles cell line (CTR cells). Our experimental system was designed based on the premise that wild Cx. tritaeniorhynchus mosquitoes naturally infected with CxFV are superinfected with JEV by feeding on JEV-infected animals. As a result, we found no evidence of the superinfection exclusion of both JEV and DENV by pre-existing CxFV infection at the cellular level. However, JEV superinfection induced severe cytopathic effects on persistently CxFV-infected CTR cells. These observations imply the possibility that JEV superinfection in CxFV-infected Cx. tritaeniorhynchus mosquitoes has an adverse effect on their fitness.


Subject(s)
Culex/physiology , Flaviviridae Infections/transmission , Flavivirus , Superinfection , Animals , Cell Line , Female
5.
In Vitro Cell Dev Biol Anim ; 51(7): 672-9, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25761724

ABSTRACT

Armigeres subalbatus (Coquillett) is a medically important mosquito and a model species for immunology research. We successfully established two cell lines from the neonate larvae of A. subalbatus using two different media. To our knowledge, this is the first report of an established Armigeres mosquito cell line. The cell lines, designated as Ar-3 and Ar-13, consist of adherent and diploid cells with compact colonies. Both these cell lines grow slowly after passage at a split ratio of 1:5 and a population doubling time of 2.7 and 3.0 d, respectively. Random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) was used to confirm that these lines correspond to the species of origin and are clearly distinct from seven other insect cell lines. Furthermore, reverse-transcription PCR was used to demonstrate that the Ar-3 cell line is susceptible to the Japanese encephalitis virus and two insect flaviviruses associated with Culex and Aedes mosquitoes but relatively insensitive to dengue virus. These data indicate that the newly established cell lines are cellular models of A. subalbatus as well as beneficial tools for the propagation of viruses associated with the Armigeres mosquito.


Subject(s)
Cell Line/virology , Culicidae/cytology , Culicidae/virology , Animals , Culicidae/genetics , Dengue Virus/pathogenicity , Encephalitis Virus, Japanese/pathogenicity , Female , Flavivirus/pathogenicity , Larva/cytology , Primary Cell Culture/methods , Random Amplified Polymorphic DNA Technique , Reverse Transcriptase Polymerase Chain Reaction
6.
J Exp Zool B Mol Dev Evol ; 324(1): 68-76, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25504930

ABSTRACT

The male sex pheromone of the longicorn beetle, Xylotrechus pyrrhoderus pyrrhoderus Bates (Cerambycidae: Tribe Clytini) plays an important role in attracting females. This pheromone is produced by the pheromone gland located in the prothorax. However, the detailed structure and underlying developmental process of this gland are still unknown. We investigated the gland structure by using histological analysis and confirmed that the gland consists of the following parts: gland cell mass, a unique spherical space in the cuticle layer, and ductules connecting the gland cells with the spherical space and conducting canals to the outer opening. The gland structure first appeared male-specific in the late pupal stage, during which the epidermal cells began depositing the exocuticle; the development of the gland was completed after adult emergence. Furthermore, we verified the structural equivalents of the X. p. pyrrhoderus male pheromone gland in 11 species of 2 tribes, Clytini and Anaglyptini. The glands of these insects could be classified into four types on the basis of the absence or presence of the spherical space and the division of the gland cell mass layer. Most noteworthy, all the species with the spherical space and division-type gland were restricted to the Xylotrechus clade, as inferred from the molecular phylogenetic analysis. These results suggest that Clytini and Anaglyptini species share a fundamental process of male pheromone gland development, and that the Japanese Xylotrechus species might have established their current status by developing distinct structural features in the male pheromone gland.


Subject(s)
Coleoptera/anatomy & histology , Coleoptera/growth & development , Exocrine Glands/anatomy & histology , Exocrine Glands/growth & development , Animals , Base Sequence , Coleoptera/classification , Male , Molecular Sequence Data , Phylogeny , Pupa/anatomy & histology , Pupa/growth & development , Sex Attractants
7.
J Chem Ecol ; 40(10): 1146-51, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25301500

ABSTRACT

Males of the cerambycid beetle Xylotrechus pyrrhoderus release a mixture of (S)-2-hydroxy-3-octanone [(S)-1] and (2S,3S)-2,3-octanediol [(2S,3S)-2] as a sex pheromone that attracts conspecific females. The chemical structures of these pheromone components include a common motif and are assumed to be biosynthetically related. Here, we show that deuterated (S)-1, applied on the cuticle of a pronotal pheromone gland, was converted into (2S,3S)-2, that included deuterium atoms, but a reverse conversion did not take place. These results reveal a carbonyl reductase to be active in the pheromone gland, and that the ketol is a biosynthetic precursor of the diol. Males did not produce (R)-1; however, deuterated (R)-1 was converted into (2R,3R)-2, indicating an attack of the enzyme from the opposite side of the hydroxyl group at the 2-position. Furthermore, to understand the substrate specificity of the enzyme, racemates of 2-hydroxy-3-hexanone and 2-hydroxy-3-decanone were synthesized and applied to the gland. Their conversion into the corresponding diols suggests that the enzyme reduces the carbonyl group at the 3-position, regardless of the chain length.


Subject(s)
Coleoptera/physiology , Sex Attractants/metabolism , Vitis/parasitology , Animals , Female , Ketones/analysis , Ketones/metabolism , Male , Octanols/analysis , Octanols/metabolism , Oxidation-Reduction , Sex Attractants/analysis
8.
Arch Virol ; 158(11): 2273-84, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23728735

ABSTRACT

In this study, we isolated and characterized an insect nidovirus from the mosquito Culex tritaeniorhynchus Giles (Diptera: Culicidae) in Vietnam, as an additional member of the new family Mesoniviridae in the order Nidovirales. The virus, designated "Dak Nong virus (DKNV)," shared many characteristics with Cavally virus and Nam Dinh virus, which have also been discovered recently in mosquitoes, and these viruses should be considered members of a single virus species, Alphamesonivirus 1. DKNV grew in cultured mosquito cells but could not replicate in the cultured vertebrate cells tested. N-terminal sequencing of the DKNV structural proteins revealed two posttranslational cleavage sites in the spike glycoprotein precursor. DKNV is assumed to be a new member of the species Alphamesonivirus 1, and the current study provides further understanding of viruses belonging to the new family Mesoniviridae.


Subject(s)
Culex/virology , Insect Viruses/classification , Insect Viruses/isolation & purification , Nidovirales/classification , Nidovirales/isolation & purification , Amino Acid Sequence , Animals , Base Sequence , Cell Line , Chlorocebus aethiops , Cricetinae , Female , Insect Viruses/genetics , Insect Viruses/growth & development , Molecular Sequence Data , Nidovirales/genetics , Nidovirales/growth & development , Phylogeny , Sequence Analysis, DNA , Vero Cells , Vietnam , Viral Proteins/chemistry , Viral Proteins/genetics , Viral Proteins/metabolism
9.
Am J Trop Med Hyg ; 88(4): 681-8, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23358634

ABSTRACT

Japanese encephalitis virus (JEV) infection in mosquitoes was monitored in Vietnam from 2006 to 2008. A total of 15,225 mosquitoes, identified as 26 species in five genera were collected and 12,621 were grouped into 447 pools for examination of JEV infection by assays for cytopathic effects in C6/36 cells and by RT-PCR to detect flavivirus RNA. Three JEV strains were isolated from Culex tritaeniorhynchus Giles collected in northern and southern Vietnam and two JEV strains were isolated from Culex vishnui Theobald collected in the highlands of Vietnam. Genetic and phylogenetic analyses, based on complete E gene nucleotide sequences, revealed that the five JEV strains were classified into the genotype I group and six amino acid differences were found in these five strains. These results indicated that multiple JEV genotype I populations are circulating countrywide in Vietnam, transmitted by bites of their Cx. tritaeniorhynchus and Cx. vishnui.


Subject(s)
Culex/virology , Encephalitis Virus, Japanese/classification , Insect Vectors/virology , Amino Acid Sequence , Animals , Base Sequence , Cell Line , Encephalitis Virus, Japanese/isolation & purification , Encephalitis Virus, Japanese/pathogenicity , Encephalitis, Japanese/virology , Genes, Viral , Genetic Variation , Genotype , Membrane Glycoproteins/analysis , Membrane Glycoproteins/genetics , Phylogeny , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction , Vietnam , Viral Envelope Proteins/analysis , Viral Envelope Proteins/genetics
10.
In Vitro Cell Dev Biol Anim ; 48(6): 369-76, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22706601

ABSTRACT

We established a continuous cell line from the embryo of the mosquito Culex tritaeniorhynchus Giles (Diptera: Culicidae), a known major vector of the Japanese encephalitis virus (family Flaviviridae, genus Flavivirus) in Asia. The cell line, designated NIID-CTR, was serially subcultured in VP-12 medium supplemented with 10 % heat-inactivated fetal bovine serum (FBS). It continued to grow for more than 60 passages over a 750-d period. The NIID-CTR cell line mainly comprised two morphologically distinct types of cells with adhesive properties: spindle-shaped and round cells. Most of the NIID-CTR cells at the 45th passage were diploid (2n = 6). The growth kinetics of the NIID-CTR cells was significantly affected by the FBS concentration in the medium. The population doubling time of the NIID-CTR cells was 20 h in the presence of 10 % FBS and 76 h in its absence. The DNA sequence of the mitochondrial cytochrome oxidase I gene confirmed that the NIID-CTR cell line was derived from C. tritaeniorhynchus. The cells were highly susceptible to Japanese encephalitis and Dengue viruses, thus providing a valuable tool for the study of mosquito-borne flaviviruses.


Subject(s)
Cell Culture Techniques/methods , Cell Line , Culex/cytology , Electron Transport Complex IV/genetics , Animals , Culex/virology , Dengue Virus/pathogenicity , Electron Transport Complex IV/biosynthesis , Encephalitis Virus, Japanese/pathogenicity , Molecular Sequence Data , Primary Cell Culture , Sequence Analysis, DNA
11.
Arch Virol ; 157(5): 975-9, 2012 May.
Article in English | MEDLINE | ID: mdl-22297417

ABSTRACT

Culex flavivirus (CxFV) is an insect-specific flavivirus that has recently been detected in various Culex spp. mosquitoes worldwide. Here, we report the successful construction of a full-length infectious cDNA clone of a Tokyo strain, CxFV-NIID21. The full-length CxFV-NIID21 cDNA was cloned into the low-copy-number plasmid pMW119, which was stably amplified in Escherichia coli. Transfection of a mosquito cell line with in vitro-transcribed RNA from the cDNA clone resulted in the production of recombinant progeny virus with growth properties, cytopathogenicity, and virion morphology similar to the parental virus.


Subject(s)
Culex/virology , DNA, Complementary/genetics , Flavivirus/genetics , RNA, Viral/genetics , Animals , Cell Line , DNA, Complementary/metabolism , Flavivirus/isolation & purification , Flavivirus/physiology , Plasmids/genetics , Plasmids/metabolism , RNA, Viral/metabolism , Species Specificity
12.
J Med Entomol ; 49(1): 175-82, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22308786

ABSTRACT

To investigate the possible spread of West Nile virus (WNV) into Japan, we carried out entomological surveillance for flaviviruses at migratory bird stopover sites in Hokkaido, Japan, during 2003-2006. A total of 3,826 mosquitoes, identified as 15 species in five genera, were collected and 2,465 of these were grouped into 123 pools that were assayed for cytopathic effects on mosquito and mammalian cell cultures and for flavivirus RNA by reverse transcription-polymerase chain reaction using flavivirus universal primer sets for fragments of the NS3 and NS5 genes. Neither WNV nor other mosquito-vertebrate transmitted flaviviruses were detected in mosquitoes collected at any of the sites in Hokkaido, but five Culex flaviviruses and one novel Aedes galloisi flavivirus were identified from Culex pipiens L. s. l. and Aedes galloisi Yamada, respectively. Genetic and phylogenetic analyses based on the partial NS5 nucleotide sequences classified Aedes galloisi flavivirus with the insect flavivirus, but distant from Cell fusing agent, Kamiti river virus, and Culex flaviviruses, showing <74% sequence identities. Polymerase chain reaction-based bloodmeal analysis of 79 females showed that all of the Aedes and Ochlerotatus mosquitoes fed on mammals (deer and humans), whereas, Cx. pipiens s. l. mosquitoes fed on both of avian (ducks and sparrows, 85.7%) and mammalian hosts (dog, 14.3%). We suggest that to date WNV has not become established in Japan.


Subject(s)
Aedes/virology , Animal Migration , Bird Diseases/virology , Culicidae/virology , Flavivirus/classification , Flavivirus/isolation & purification , Animals , Bird Diseases/epidemiology , Birds , Deer/blood , Feeding Behavior , Female , Flavivirus/genetics , Humans , Japan/epidemiology , Phylogeny , Population Surveillance
13.
J Virol ; 85(13): 6185-96, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21507977

ABSTRACT

Among members of the order Mononegavirales, RNA splicing events have been found only in the family Bornaviridae. Here, we report that a new rhabdovirus isolated from the mosquito Culex tritaeniorhynchus replicates in the nuclei of infected cells and requires RNA splicing for viral mRNA maturation. The virus, designated Culex tritaeniorhynchus rhabdovirus (CTRV), shares a similar genome organization with other rhabdoviruses, except for the presence of a putative intron in the coding region for the L protein. Molecular phylogenetic studies indicated that CTRV belongs to the family Rhabdoviridae, but it is yet to be assigned a genus. Electron microscopic analysis revealed that the CTRV virion is extremely elongated, unlike virions of rhabdoviruses, which are generally bullet shaped. Northern hybridization confirmed that a large transcript (approximately 6,500 nucleotides [nt]) from the CTRV L gene was present in the infected cells. Strand-specific reverse transcription-PCR (RT-PCR) analyses identified the intron-exon boundaries and the 76-nt intron sequence, which contains the typical motif for eukaryotic spliceosomal intron-splice donor/acceptor sites (GU-AG), a predicted branch point, and a polypyrimidine tract. In situ hybridization exhibited that viral RNAs are primarily localized in the nucleus of infected cells, indicating that CTRV replicates in the nucleus and is allowed to utilize the host's nuclear splicing machinery. This is the first report of RNA splicing among the members of the family Rhabdoviridae.


Subject(s)
Culex/virology , RNA Splicing , Rhabdoviridae/genetics , Amino Acid Sequence , Animals , Base Sequence , Cell Line , Cell Nucleus/metabolism , Cell Nucleus/virology , Genome, Viral/genetics , Introns , Microscopy, Electron , Molecular Sequence Data , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Viral/genetics , RNA, Viral/metabolism , Rhabdoviridae/classification , Rhabdoviridae/ultrastructure , Sequence Analysis, DNA , Viral Proteins/genetics , Virus Replication
14.
Virus Res ; 155(1): 147-55, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20875466

ABSTRACT

Two infectious agents were isolated from Culex species mosquitoes in Japan and were identified as distinct strains of a new RNA virus by a method for sequence-independent amplification of viral nucleic acids. The virus designated Omono River virus (OMRV) replicated in mosquito cells in which it produced a severe cytopathic effect. Icosahedral virus particles of approximately 40 nm in diameter were detected in the cytoplasm of infected cells. The OMRV genome was observed to consist of a nonsegmented, 7.6-kb double-stranded RNA (dsRNA) and contain two overlapping open reading frames (ORFs), namely ORF1 and ORF2. ORF1 was found to encode a putative dsRNA-binding protein, a major capsid protein, and other putative proteins, which might be generated by co- and/or post-translational processing of the ORF1 polyprotein precursor, and ORF2 was found to encode a putative RNA-dependent RNA polymerase (RdRp), which could be translated as a fusion with the ORF1 product by a -1 ribosomal frameshift. Phylogenetic analysis based on RdRp revealed that OMRV is closely related to penaeid shrimp infectious myonecrosis virus and Drosophila totivirus, which are tentatively assigned to the family Totiviridae. These results indicated that OMRV is a new member of the family of nonsegmented dsRNA viruses infecting arthropod hosts, but not fungal or protozoan hosts.


Subject(s)
Culex/virology , RNA, Double-Stranded/genetics , RNA, Viral/genetics , Totiviridae/genetics , Totiviridae/isolation & purification , Animals , Cell Line , Cluster Analysis , Cytopathogenic Effect, Viral , Cytoplasm/virology , Japan , Microscopy, Electron, Transmission , Molecular Sequence Data , Open Reading Frames , Phylogeny , Sequence Analysis, DNA , Sequence Homology , Totiviridae/classification , Totiviridae/ultrastructure , Viral Proteins/genetics , Virion/ultrastructure
15.
Influenza Res Treat ; 2011: 652652, 2011.
Article in English | MEDLINE | ID: mdl-23074659

ABSTRACT

The 2003-2004 H5N1 highly pathogenic avian influenza (HPAI) outbreaks in Japan were the first such outbreaks in 79 years in Japan. Epidemic outbreaks have been occurring in Southeast Asia, with the most recent in 2010. Knowledge of the transmission route responsible for the HPAI outbreaks in these countries remains elusive. Our studies strongly suggested that field and laboratory studies focusing on mechanical transmission by blow flies should be considered to control H5N1 avian influenza outbreaks, in particular in epidemic areas, where there are high densities of different fly species throughout the year. In this paper, we review these field and laboratory entomological studies and discuss the possibility of blow flies transmitting H5N1 viruses.

16.
Jpn J Infect Dis ; 63(6): 401-4, 2010 Nov.
Article in English | MEDLINE | ID: mdl-21099089

ABSTRACT

A laboratory colony of the mosquito Aedes japonicus japonicus, which has recently invaded the United States and is recognized as a highly competent vector of West Nile virus, was established from larvae collected in Narita, Japan. The mosquitoes were maintained with induced insemination, blood-feeding on humans, and oviposition in water provided from the original collection site during the first few generations, then the colony was transferred to a large cage (40×40×100 cm in height) and adapted to conditions in which specimens were allowed to mate freely. White mice were provided as the blood source, and deionized water was available for oviposition. Approximately 185 eggs, most of which were tolerant to desiccation for at least 1 month, with some surviving for up to 2.5 months, were obtained per female following a single blood-feeding. The rate of successful emergence was nearly 90%, although this rate decreased significantly at high larval densities. The colony has been maintained for 5 years, and developmental profiles of the species have been obtained during that time.


Subject(s)
Aedes/growth & development , Aedes/physiology , Laboratory Animal Science/methods , Aedes/classification , Animals , Behavior, Animal , Feeding Behavior , Female , Humans , Insect Vectors , Japan , Larva/growth & development , Larva/physiology , Male , Mice , Oviposition , Species Specificity
17.
J Med Entomol ; 47(3): 442-50, 2010 May.
Article in English | MEDLINE | ID: mdl-20496592

ABSTRACT

To evaluate the vectorial capacity of mosquitoes for viruses in Japan, the host-feeding habits of the mosquitoes were analyzed by sequencing polymerase chain reaction-amplified fragments of the cytochrome b and 16S ribosomal RNA regions of the mitochondrial DNA of 516 mosquitoes of 15 species from seven genera that were collected from residential areas during 2003-2006. Culex pipiens L. and Aedes albopictus Skuse were the most commonly collected species in urban and suburban residential areas. Anautogenous Culex pipiens pallens Coquillett was distinguished from the autogenous Cx. pipiens form molestus Forskal using a polymerase chain reaction-based identification method. Both Cx. p. pallens and Cx. p. form molestus exhibited similar host-feeding habits, broadly preferring avian (50.0 and 42.5% of avian, respectively) and mammalian (38.6 and 45.0% of avian, respectively) hosts, such as tree sparrows, ducks, and humans. Conversely, Ae. albopictus exhibited a highly mammalophilic and anthropophilic feeding pattern, with 84.2% feeding on mammalian hosts and 68.5% of these on humans. We concluded that in Japan, Cx. pipiens might play a significant role in the avian-to-mammal transmission of viruses, such as West Nile virus, whereas Ae. albopictus might play a role in the human-human transmission of dengue and Chikungunya viruses.


Subject(s)
Aedes/physiology , Culex/physiology , Culicidae/virology , Aedes/genetics , Aedes/virology , Alphavirus Infections/epidemiology , Animals , Birds/parasitology , Chikungunya virus , Culex/genetics , Culex/virology , DNA Primers , Feeding Behavior , Humans , Japan/epidemiology , Polymerase Chain Reaction , Population Density , Seasons , Suburban Population , Urban Population
18.
Biosci Biotechnol Biochem ; 73(10): 2252-6, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19809185

ABSTRACT

Adult males of the grape borer, Xylotrechus pyrrhoderus, secrete (S)-2-hydroxy-3-octanone [(S)-1] and (2S,3S)-2,3-octanediol [(2S,3S)-2] from their nota of prothoraces as sex pheromone components. Their structural similarity suggests that one of them is the biosynthetic precursor of the other component. In order to confirm the biochemical conversion, deuterated derivatives of both components were synthesized by starting from a Wittig reaction between hexanal and an ylide derived from D(5)-iodoethane and ending with enantiomeric resolution by chiral HPLC. The molecular ions of 1 and 2 could scarcely be detected by using a GC-MS analysis, and the labeled compounds showed similar mass spectra to the unlabeled pheromone components. However, several fragment ions, including four deuterium atoms, were observed in the mass spectra of their acetate derivatives, indicating that the conversion could be confirmed by examining a compound with the diagnostic ions after acetylation of the volatiles collected from insects treated with the labeled precursors.


Subject(s)
Coleoptera/chemistry , Deuterium/chemistry , Sex Attractants/chemistry , Sex Attractants/chemical synthesis , Animals , Coleoptera/metabolism , Hydrocarbons, Iodinated/chemistry , Male , Mass Spectrometry , Sex Attractants/biosynthesis , Stereoisomerism
19.
J Med Entomol ; 46(4): 852-5, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19645288

ABSTRACT

In a previous study, the highly pathogenic avian influenza (HPAI) H5N1 viruses were isolated from blow flies collected at the Tamba Town of Kyoto prefecture during the outbreak period in March 2004. In this study, we carried out virus exposure experiments to investigate whether the H5N1 virus would survive in a blow fly, Calliphora nigribarbis. The virus exposure experiments showed that the H5N1 influenza virus was isolated from the crop and intestine of C. nigribarbis for at least 24 h, and the viruses remained viable with titers ranging from 0.5 to 4.63 TCID50. This result suggests that C. nigribarbis could possibly transport the H5N1 virus over a distance of 2 km, which is the distance they can migrate within 24 h.


Subject(s)
Diptera/virology , Influenza A Virus, H5N1 Subtype/physiology , Insect Vectors/virology , Animals , Influenza A Virus, H5N1 Subtype/isolation & purification , Intestines/virology , Time Factors , Virus Replication
20.
Jpn J Infect Dis ; 62(4): 294-7, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19628908

ABSTRACT

A mark-release-recapture study of the dispersal ability of blow flies, Calliphora nigribarbis, was conducted in Ikumo-Naka, Ato Town, Yamaguchi Prefecture, Japan in December 2004. A location where a fatal avian influenza outbreak had occurred 1 year previously was selected for the present study. A total of 3,884 C. nigribarbis were collected, 1,915 of which were marked and released from 4 different collection sites during 2 successive days. The recapture rate of the released C. nigribarbis ranged from 0.014 to 0.029 among the collection sites, and the overall recapture rate was calculated as 0.022. Based on the distance between the released site and the recaptured site, the dispersal rate of C. nigribarbis was estimated as 256 m/h on the 1st day and 179 m/h on the 2nd day of the experiment, and the maximum dispersal rate observed in this study was estimated as 500 m/h. Taking into account the active period of C. nigribarbis on a fine day (7 h/day), the distance traveled by C. nigribarbis within a day was estimated as 1,789 and 1,250 m/day on average for the 1st and 2nd days, respectively, and the maximum distance was 3,500 m/day. These results suggest that C. nigribarbis could play a role in the mechanical dissemination of avian influenza virus and spread of the outbreak in Japan.


Subject(s)
Diptera/physiology , Animals , Disease Vectors , Humans , Influenza, Human/transmission , Japan
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