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1.
Fish Shellfish Immunol ; 88: 161-169, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30802628

RESUMO

Lysozyme is an important defense molecule of the innate immune system and possess high antimicrobial activities. In this study, a full-length c-type lysozyme cDNA (Fplysc) was cloned and characterized from Fenneropenaeus penicillatus. The cDNA contains an open reading frame of 477 bp encoding 158 amino acids, with 53-94% identity with those of other crustaceans. The recombinant Fplysc had antibacterial activities against Gram-positive bacteria (Streptococcus agalactiae and Micrococcus luteus) and Gram-negative bacteria (Vibrio alginolyticus and Escherichia coli), and showed antiviral activity against WSSV and IHHNV. The qRT-PCR analysis showed that Fplysc expression levels were most abundant in hemocytes and less in eyestalk. The expression levels of Fplysc were significantly upregulated in gill, intestine and hemocytes when challenged with WSSV and V. alginolyticus. Fplysc-silencling suppressed Fplysc expression in cephalothoraxes and increased mortality caused by WSSV and V. alginolyticus, and exogenous rFplysc led to a significant decrease of shrimp mortality by injecting rFplysc into Fplysc silenced shrimp, suggesting Fplysc is the important molecule in shrimp antimicrobial and antiviral response. In conclusion, the results provide some insights into the function of Fplysc in shrimp against bacterial and viral infection.


Assuntos
Proteínas de Artrópodes/imunologia , Penaeidae/imunologia , Sequência de Aminoácidos , Animais , Proteínas de Artrópodes/química , Proteínas de Artrópodes/genética , Clonagem Molecular , Densovirinae/fisiologia , Escherichia coli/fisiologia , Hemócitos , Imunidade Inata , Micrococcus luteus/fisiologia , Muramidase/química , Muramidase/genética , Muramidase/metabolismo , Penaeidae/genética , Penaeidae/microbiologia , Penaeidae/virologia , Streptococcus agalactiae/fisiologia , Vibrio alginolyticus/fisiologia , Vírus da Síndrome da Mancha Branca 1/fisiologia
2.
J Fish Dis ; 42(3): 447-454, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30659620

RESUMO

White leg shrimp, Penaeus vannamei, were collected on a monthly basis from grow-out ponds located at Tamil Nadu and Andhra Pradesh states along the east coast of India for screening of viral and other pathogens. Totally 240 shrimp samples randomly collected from 92 farms were screened for white spot syndrome virus (WSSV), infectious hypodermal and haematopoietic necrosis virus (IHHNV), infectious myonecrosis virus (IMNV) and Enterocytozoon hepatopenaei (EHP). The number of shrimp collected from shrimp farms ranged from 6 to 20 based on the body weight of the shrimp. All the shrimp collected from one farm were pooled together for screening for pathogens by PCR assay. Among the samples screened, 28 samples were WSSV-positive, one positive for IHHNV and 30 samples positive for EHP. Among the positive samples, four samples were found to be positive for both WSSV and EHP, which indicated that the shrimp had multiple infections with WSSV and EHP. This is the first report on the occurrence of multiple infections caused by WSSV and EHP. Multiplex PCR (m-PCR) protocol was standardized to detect both pathogens simultaneously in single reaction instead of carrying out separate PCR for both pathogens. Using m-PCR assay, naturally infected shrimp samples collected from field showed two prominent bands of 615 and 510 bp for WSSV and EHP, respectively.


Assuntos
Densovirinae/isolamento & purificação , Enterocytozoon/isolamento & purificação , Penaeidae/microbiologia , Penaeidae/virologia , Vírus da Síndrome da Mancha Branca 1/isolamento & purificação , Animais , Aquicultura , Coinfecção , Infecções por Vírus de DNA , Índia , Microsporidiose , Reação em Cadeia da Polimerase Multiplex/métodos
4.
Anal Chim Acta ; 1040: 105-111, 2018 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-30327099

RESUMO

Molecular diagnosis of genome is one of the major methods for pathogens detection. The commonly used PCR method can realize an exponential amplification of the target gene but is time-consuming. In this work, we proposed a duplex and visual method using rapid PCR combined with molecular beacons to specifically detect two kinds of shrimp pathogens in one reaction tube. We only need to observe the fluorescence change of the reaction tube with naked eye to determine the result. A home-made automatic transfer equipment allows reaction tubes shuttling quickly between two water baths to achieve rapid PCR amplification. A simple device was also designed to present the detection results easily determined with naked eye. This duplex and visual detection method is fast, low-cost and of high specificity. From DNA extraction to results judgment, only 15 min was enough. Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) and Vibrio parahaemolyticus (VP) are two common shrimp pathogens which were chosen as our detection objects. This method may give a possibility to conduct end-point visual duplex detection, which may make a positive influence on the pathogen prevention.


Assuntos
Densovirinae/genética , Penaeidae/genética , Reação em Cadeia da Polimerase , Vibrio parahaemolyticus/genética , Animais , Densovirinae/patogenicidade , Vibrio parahaemolyticus/patogenicidade
5.
J Invertebr Pathol ; 157: 100-103, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30130537

RESUMO

Infectious hypodermal and haematopoietic necrosis virus (IHHNV) infects many crustacean hosts, including cultured penaeid shrimp. In the present study, we aimed to develop a novel sensitive SYBR Green-based real-time PCR method to specifically amplify DNA fragments of IHHNV. Our newly developed real-time PCR method with a 195-bp amplicon specifically detected IHHNV and showed no cross reaction with white spot syndrome virus (WSSV), hepatopancreatic parvovirus (HPV), Enterocytozoon hepatopenaei (EHP), infectious myonecrosis virus (IMNV) and yellow-head virus (YHV). This method could detect as low as one single copy of IHHNV plasmid DNA, more sensitive than other SYBR Green-based real-time PCR methods and less expensive and more convenient than the TaqMan probe-based real-time PCR. Moreover, our data using the newly designed method showed that 80% of IHHNV-fed Procambarus clarkii samples were IHHNV positive. Our findings further confirmed that P. clarkii can be infected by IHHNV.


Assuntos
Astacoidea/virologia , Densovirinae , Infecções por Parvoviridae/veterinária , Reação em Cadeia da Polimerase em Tempo Real/métodos , Animais , DNA Viral
6.
Dis Aquat Organ ; 129(2): 145-158, 2018 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-29972375

RESUMO

Infectious hypodermal and hematopoietic necrosis virus (IHHNV) can cause mass mortalities in western blue shrimp Penaeus stylirostris, runt deformity syndrome in Pacific white shrimp P. vannamei and scalloped abdominal shell deformities in black tiger shrimp P. monodon. In P. monodon, however, PCR-based diagnosis of IHHNV can be complicated by the presence of a chromosome-integrated, non-replicating endogenous viral element (EVE). To facilitate high-throughput screening of P. monodon for IHHNV infection and/or EVE sequences, here we report real-time PCR tests designed to specifically detect IHHNV Lineage I, II and III but not EVE Type A sequences and vice versa. Using 108 dsDNA copies of plasmid (p)DNA controls containing either IHHNV or EVE-Type A sequences, both tests displayed absolute specificity. The IHHNV-q309 PCR reliably detected down to ≤10 copies of pDNA, at which levels a 309F/R PCR amplicon was just detectable, and the presence of an IHHNV-EVE sequence did not significantly impact its sensitivity. The IHHNV-qEVE PCR was similarly sensitive. Testing of batches of P. monodon clinical samples from Vietnam/Malaysia and Australia identified good diagnostic concordance between the IHHNV-q309 and 309F/R PCR tests. As expected for a sequence integrated into host chromosomal DNA, IHHNV-qEVE PCR Ct values were highly uniform among samples from shrimp in which an EVE was present. The highly specific and sensitive IHHNV-q309 and IHHNV-qEVE real-time PCR tests described here should prove useful for selecting broodstock free of IHHNV infection and in maintaining breeding populations of P. monodon specific pathogen free for IHHNV, and if desired, also free of IHHNV-EVE sequences.


Assuntos
DNA Viral/genética , Densovirinae/fisiologia , Penaeidae/virologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Animais , Densovirinae/genética , Genoma Viral , Interações Hospedeiro-Patógeno
7.
Indian J Med Res ; 147(1): 88-96, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29749366

RESUMO

Background & objectives: There are reports about the susceptibility of Aedes mosquitoes to ZIKV from various countries, however, no such information is available from Indian sub-continent, although, high level of group cross-reactivity of ZIKV with other flaviviruses has been reported. During outbreak situations, many cases of Dengue (DEN) and Chikungunya (CHIK) are reported. In such scenario, vector mosquitoes are likely to get co-infection/secondary-infection with one or other virus. The present study was carried out to determine the susceptibility of Indian strain of Aedes aegypti to Zika virus (ZIKV) strain (MR-766) and the effect of co-infection/super-infection with either dengue virus (serotype-2) (DENV) or chikungunya virus (CHIKV) on ZIKV replication. Methods: Ae. aegypti mosquitoes used in this study were reared for many generations since 1980 at laboratory colony maintained at the ICMR-National Institute of Virology, Pune, India. Transmissibility of ZIKV from infected mosquitoes to suckling mice was also studied. Mosquitoes were experimentally infected with ZIKV and super-infected with either DENV or CHIKV via membrane-feeding route and incubated for 14 days at 28±2°C and humidity of 85±5 per cent. Replication of these viruses in mosquitoes was confirmed using real-time reverse transcription-polymerase chain reaction and immunofluorescence assay. Twenty infected mosquitoes were allowed to feed upon four suckling CD1 mice for about 30 min. Transmission of the ZIKV by infected mosquitoes to suckling mice was confirmed by the appearance of clinical signs and the presence of viral RNA in different organs. Results: Concomitant infection of mosquitoes with all the three viruses showed simultaneous propagation of all three viruses, confirmed by real time RT-PCR and IFA. Infection of mosquitoes with CHIKV followed by ZIKV showed positivity in individual head squashes (7%) for both viruses using IFA; only 8.3 per cent showed dual positivity with primary infection of ZIKV followed by DENV; 8.3 per cent dual infection positivity was observed when infected with DENV followed by ZIKV; 5 per cent showed dual infection was observed when infected with ZIKV followed by CHIKV. Ae. aegypti was found to be susceptible to ZIKV strain as ZIKV could be detected from the second post-infection day (PID) in infected mosquitoes. Transmission of ZIKV to mice by the bite of infected Ae. aegypti establishes this species as a potential vector. Interpretation & conclusions: From super-infection experiments, it was concluded that ZIKV might have a relative advantage in replication dynamics over DENV. Vertical transmission was not observed for ZIKV in experimentally infected mosquitoes (n=920 larvae). Further studies are required to understand the possibility of silently circulating ZIKV in India, which remain non-detected because of lack of surveillance.


Assuntos
Febre de Chikungunya/virologia , Coinfecção/virologia , Dengue/virologia , Infecção por Zika virus/virologia , Animais , Febre de Chikungunya/epidemiologia , Febre de Chikungunya/transmissão , Vírus Chikungunya/patogenicidade , Coinfecção/epidemiologia , Coinfecção/transmissão , Dengue/epidemiologia , Dengue/transmissão , Vírus da Dengue/patogenicidade , Densovirinae , Surtos de Doenças , Humanos , Índia/epidemiologia , Larva/virologia , Mosquitos Vetores/virologia , Replicação Viral/genética , Zika virus/patogenicidade , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/transmissão
9.
Artigo em Inglês | MEDLINE | ID: mdl-29164671

RESUMO

Insect innate immunity relies on numerous soluble and membrane-bound receptors, named pattern recognition proteins (PRPs), which enable the insect to recognize pathogen-associated molecular patterns. C-type lectins are among the best-studied PRPs and constitute the most diverse family of animal lectins. Here we have characterized two groups of Spodoptera exigua C-type lectins that differ in their phylogeny, domain architecture, and expression pattern. One group includes C-type lectins with similar characteristics to other lepidopteran lectins, and a second group includes bracoviral-related lectins (bracovirus-like lectins, Se-BLLs) recently acquired by horizontal gene transfer. Subsequently, we have investigated the potential role of some selected lectins in the susceptibility to Junonia coenia densovirus (JcDV). For this purpose, three of the bracoviral-related lectins were expressed, purified, and their effect on the densovirus infection to two different Spodoptera species was assessed. The results showed that Se-BLL3 specifically reduce the mortality of Spodoptera frugiperda larvae caused by JcDV. In contrast, no such effect was observed with S. exigua larvae. In a previous work, we have also shown that Se-BLL2 increased the tolerance of S. exigua larvae to baculovirus infection. Taken together, these results confirm the implication of two different C-type lectins in antiviral response and reflect the biological relevance of the acquisition of bracoviral genes in Spodoptera spp.


Assuntos
Densovirinae/fisiologia , Proteínas de Insetos/genética , Lectinas Tipo C/genética , Spodoptera/genética , Spodoptera/imunologia , Animais , Proteínas de Insetos/metabolismo , Larva/genética , Larva/crescimento & desenvolvimento , Larva/imunologia , Larva/virologia , Lectinas Tipo C/metabolismo , Filogenia , Análise de Sequência de DNA , Especificidade da Espécie , Spodoptera/crescimento & desenvolvimento , Spodoptera/virologia
10.
J Invertebr Pathol ; 145: 31-38, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28315365

RESUMO

Mosquito cell lines (C6/36) were reported in the literature to support the propagation of Penaeus monodon hepandensovirus (PmoHDV). We aim to evaluate the susceptibility and viral propagation of P. merguiensis hepandensovirus (PmeHDV) which is ∼22% different to PmoHDV in Aedes albopictus cell line (C6/36). Cellular changes in the infected cell culture were detected. Vacuole formation was seen in both infected and uninfected cell cultures. The average number of disrupted cellular membranes in the infected cells (presumptive dead cells) was significantly higher than that of uninfected cells at passage two (F=9.749, d.f. 1, 22, p<0.05). Using a proliferation assay, light absorption of infected cells peaked at 2weeks post-infection (O.D.=0.27) but was significantly lower than that of the uninfected groups (O.D.=0.37) (F=6.879, d.f. 1, 94, p<0.05) suggesting hindered cell growth. PCR of the serial passages of the infected cell cultures indicated weak positive results for PmeHDV infection and TaqMan quantitative PCR confirmed that the average number of viral copies declined from 3.8×105 to 5.69×102 copies per µL and the mean of cycle times increased from 19.26 to 27.63. These results are interpreted to mean C6/36 allows the initial stage of PmeHDV replication, but the virus was incapable of using C6/36 for patent replication of its' virions.


Assuntos
Culicidae/virologia , Densovirinae , Animais , Linhagem Celular , Replicação Viral
11.
Fish Shellfish Immunol ; 59: 95-102, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27744059

RESUMO

The widespread overuse of antibiotics in aquaculture has led to the emergence of antibiotic-resistance shrimp pathogens, the negative impact on shrimp gut microbiota, and the presence of antimicrobial residues in aquaculture products, with negative consequences on human health. Alternatively, probiotics have positive effects on immunological responses and productive performance of aquatic animals. In this study, three probiotic bacteria, (Bacillus licheniformis MAt32, B. subtilis MAt43 and B. subtilis subsp. subtilis GAtB1), isolated from the Anadara tuberculosa were included in diets for juvenile shrimp, Litopenaeus vannamei, to evaluate their effects on growth, survival, disease prevalence, and immune-related gene expression. Shrimp naturally infected with WSSV and IHHNV were fed with the basal diet (control, T1) and diets supplemented with four levels of bacilli probiotic mix (1:1:1) at final concentration of (T2) 1 × 106, (T3) 2 × 106, (T4) 4 × 106, and (T5) 6 × 106 CFU g-1 of feed. The specific growth rate of shrimp was significantly higher in T2 than in T1 (control) treatment, and the final growth as well as the survival were similar among treated groups. The prevalence of WSSV and IHHNV infected shrimp was reduced in T2 and T4 treatments, respectively, compared with control. The mRNA expression of proPO gene was higher in treatment T4 than control. The LvToll1 gene was significantly up-regulated in treatments T4 and T5 compared to control. The SOD gene was up-regulated in treatment T5 compared to control. In contrast, the mRNA expression of the Hsp70 gene was down-regulated in treatments T4 and T5 respect to control, and the TGase gene remained unaffected by the level of bacillus probiotic mix. As conclusion, the bacilli probiotic mix (Bacillus spp.) enhanced immune-related gene expression in WSSV and IHHNV naturally infected shrimp. This is the first report of probiotic potential of bacteria isolated from A. tuberculosa on the immune response and viral prevalence in shrimp Litopenaeus vannamei.


Assuntos
Arcidae/microbiologia , Bacillus/imunologia , Imunidade Inata/imunologia , Penaeidae/efeitos dos fármacos , Penaeidae/fisiologia , Probióticos , Ração Animal/análise , Animais , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/metabolismo , Densovirinae/fisiologia , Dieta , Penaeidae/imunologia , Penaeidae/virologia , Probióticos/química , Regulação para Cima , Vírus da Síndrome da Mancha Branca 1/fisiologia
12.
Genet Sel Evol ; 48(1): 64, 2016 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-27605216

RESUMO

BACKGROUND: In shrimp farming, major production losses are caused by viruses. Hepatopancreatic parvovirus (HPV) is one of the viral pathogens that infect banana shrimp (Fenneropenaeus merguiensis). HPV is thought to slow down growth and cause mortality in the juvenile stages of banana shrimp. Genetic improvement through selection of shrimp resistant to viral diseases is one approach to address this issue. This is the first detailed report on an aquaculture species that investigates whether viral titre varies among families and is heritable, and thus whether viral titre per se is a possible candidate trait for selection to produce resistant stock. RESULTS: HPV titre was measured by quantitative polymerase chain reaction of DNA extracted from 1137 offspring (from 48 full-sib families). Estimated heritability of HPV titre, based on the linear animal mixed model, was moderate (h(2) = 0.41). Genetic correlations of HPV with body traits (weight, length and width of body, head and tail) ranged from -0.13 to -0.38. HPV titre was negatively correlated with raw and cooked body colour (-0.33 and -0.43, respectively). CONCLUSIONS: This is the first study based on a large dataset that provides evidence that viral titre may have a genetic component in penaeid shrimp or even in any aquaculture species. The moderate heritability estimated for this trait suggests that resistance to HPV may be achieved by selecting for low HPV titre. With moderate and negative correlations, selection for resistance to HPV should gradually improve body traits and colour of banana shrimp.


Assuntos
Densovirinae/genética , Penaeidae/genética , Penaeidae/virologia , Animais , Aquicultura/métodos , Resistência à Doença/genética , Infecções por Rhabdoviridae/genética , Infecções por Rhabdoviridae/prevenção & controle , Infecções por Rhabdoviridae/virologia , Seleção Artificial
13.
Arch Virol ; 161(11): 3189-201, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27568013

RESUMO

Infectious hypodermal and hematopoietic necrosis virus (IHHNV) is prevalent among farmed shrimp and results in significant reductions in shrimp production. In order to gain a better understanding of the prevalence of IHHNV in the Litopenaeus vannamei shrimp population of Shanghai, China, samples were collected during two cultivation seasons and subjected to diagnostic PCR. The results of this study showed that 167 out of 200 shrimp were positive for IHHNV, indicating a high viral prevalence (83.5 %) in farmed shrimp populations. Our results also indicated that there was a moderate correlation between IHHNV prevalence and water temperature, salinity and pH and only a slight correlation with the concentration of dissolved oxygen (DO). A mathematical model was developed in order to predict the relationship between these four characteristics of water quality and IHHNV prevalence, ultimately resulting in an estimate of the best water quality criteria (IHHNV prevalence = 0) where T = 30 °C pH = 8.0, DO = 18.3 mg/L, and salinity = 1.5 ‰. Additionally, two IHHNV genotypes were identified, the sequencing of which revealed a high similarity to the known IHHNV genotypes based on a comparison of their nucleotide and amino acid sequences. Two types of repetitive sequences were detected at both the 5' and 3' ends of the non-coding regions, which are commonly found in other IHHNV genomic sequences. Phylogenetic analysis indicated that the IHHNV Shanghai genotypes were closely related to strains from Ganyu and Sheyang, but not to strains originating from Fujian, China. This finding suggests that IHHNVs have emerged independently several times in China.


Assuntos
Densovirinae/classificação , Densovirinae/isolamento & purificação , Penaeidae/crescimento & desenvolvimento , Penaeidae/virologia , Animais , Aquicultura , China , Análise por Conglomerados , DNA Viral/química , DNA Viral/genética , Densovirinae/genética , Genoma Viral , Genótipo , Concentração de Íons de Hidrogênio , Modelos Teóricos , Filogenia , Reação em Cadeia da Polimerase , Prevalência , Salinidade , Análise de Sequência de DNA , Homologia de Sequência , Temperatura , Água/química
14.
Ecohealth ; 13(3): 591-596, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27342686

RESUMO

The decapod penstyldensovirus (PstDV1) is a widely spread shrimp pathogen that causes high mortalities in the shrimp Penaeus stylirostris, while in P. vannamei, it has been associated with induction of the runt deformity syndrome. Using shrimp post-larvae (PL, stages PL13-PL21) collected from 16 commercial hatcheries from Mexico, and a sensitive PCR protocol for its detection, a survey of the PstDV1 prevalence in larvae was undertaken. A high overall prevalence of PstDV1 (49.5 %) in shrimp PL from the studied hatcheries was found. This study reveals that PstDV1 occurs persistently in PL populations, which may have significant implications for its dispersal.


Assuntos
Densovirinae/isolamento & purificação , Penaeidae , Animais , México , Reação em Cadeia da Polimerase , Prevalência
15.
Integr Comp Biol ; 56(6): 1131-1143, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27252205

RESUMO

Viral pathogens are of serious concern to the culture of penaeid shrimps worldwide. However, little is known about the molecular response of shrimp to viral infection. Selective breeding has been suggested as an effective long-term strategy to manage viral disease, though more information on gene function is needed to help inform breeding programs. The study of cultured banana shrimp (Fenneropenaeus merguiensis) infected with hepatopancreatic parvo-like virus (HPV) provides a unique opportunity to explore the host response to viral infection independent of challenge testing. To gain insight into the genetic mechanisms underlying resistance to high levels of HPV, we examined hepatopancreas tissue from six full-sib groups of banana shrimp with differing levels of HPV infection for differences in gene expression. A total of 404 differentially expressed genes were identified with 180 being over-expressed and 224 under-expressed among high-HPV full-sib groups. Based on homology analysis, a large proportion of these genes were associated with processes reported to be involved in the immune response of crustaceans, including pattern recognition proteins, antimicrobial peptides, components of the prophenoloxidase system, and antiviral activity. The results indicate shrimp from high-HPV full-sib groups appear to have a lower presence of important immune response elements, yet possess upregulated putative antiviral pathways. Within the differentially expressed genes, over 4000 sequence variants were identified to be exclusive to either the high- or low-HPV full-sib groups. To our knowledge, this is the first report of differential expression analysis using RNA-Seq to explore differences in viral load among high- and low-HPV full-sib groups of cultured shrimp. This research has provided additional insight into our understanding of the mechanisms involved in the response of this shrimp species to a naturally occurring viral pathogen. Sequence variants identified in this study offer an exceptional resource for mining gene-associated markers of HPV resistance.


Assuntos
Penaeidae/genética , Penaeidae/virologia , Transcriptoma , Animais , Densovirinae/fisiologia , Perfilação da Expressão Gênica , Penaeidae/imunologia , Carga Viral
16.
J Fish Dis ; 39(10): 1225-9, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27169386

RESUMO

Infectious hypodermal and haematopoietic necrosis virus (IHHNV) and white spot syndrome virus (WSSV) are two widespread shrimp viruses. The interference of IHHNV on WSSV was the first reported case of viral interference that involved crustacean viruses and has been subsequently confirmed. However, the mechanisms underlying the induction of WSSV resistance through IHHNV infection are practically unknown. In this study, the interference mechanisms between IHHNV and WSSV were studied using a competitive ELISA. The binding of WSSV and IHHNV to cellular membrane of Litopenaeus vannamei was examined. The results suggested that there existed a mutual competition between IHHNV and WSSV for binding to receptors present on cellular membrane of L. vannamei and that the inhibitory effects of WSSV towards IHHNV were more distinct than those of IHHNV towards WSSV.


Assuntos
Membrana Celular/virologia , Densovirinae/fisiologia , Penaeidae/virologia , Vírus da Síndrome da Mancha Branca 1/fisiologia , Animais
17.
Emerg Infect Dis ; 21(10): 1827-9, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26401891

RESUMO

Aedes aegypti and Ae. albopictus mosquitoes, primary vectors of dengue and chikungunya viruses, were recently detected in California, USA. The threat of potential local transmission of these viruses increases as more infected travelers arrive from affected areas. Public health response has included enhanced human and mosquito surveillance, education, and intensive mosquito control.


Assuntos
Densovirinae/patogenicidade , Insetos Vetores/virologia , Controle de Mosquitos/métodos , Saúde Pública/métodos , Animais , California , Febre de Chikungunya/epidemiologia , Dengue/epidemiologia , Humanos
18.
Mar Genomics ; 24 Pt 3: 305-12, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26268797

RESUMO

In 1999, the causative agent of an epizootic in Cherax quadricarinatus was described, and given the provisional name Cherax quadricarinatus parvovirus-like. Sequencing of the 6334 nt genome identified three open-reading frames on the top strand coding NS3 (35.55 kDa), NS1 (67.36 kDa) and NS2 (35.18 kDa) and on the bottom strand a single open reading frame which most likely encodes 4 structural proteins. Motifs characteristic of the Densovirinae were found in the ORFs. Phylogenetic analysis of the amino acids in NS1 places the genome in the genus Ambidensovirus, most closely related to the marine sea star densovirus (75%, E=0.0) and distantly related to Acheta domestica densovirus (44.1%). The virus name is proposed as species Decapod ambidensovirus, variant Cherax quadricarinatus densovirus. This is the first Ambidensovirus to be found in decapod crustaceans and the first of the subfamily Densovirinae to be sequenced from a freshwater crayfish. Cherax quadricarinatus densovirus and sea star densovirus are the first highly related Densovirinae to infect phylogenetically disparate hosts and are thus far, unique among the Densovirinae.


Assuntos
Astacoidea/virologia , Densovirinae/genética , Genoma Viral , Animais , Clonagem Molecular , Densovirinae/isolamento & purificação , Interações Hospedeiro-Patógeno , Filogenia , Reação em Cadeia da Polimerase
19.
J Virol Methods ; 224: 16-9, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26277910

RESUMO

Decapod Penstyldensovirus 1, previously named as infectious hypodermal and hematopoietic necrosis virus (IHHNV), is an economically important pathogen that causes shrimp diseases worldwide. However, a rapid method for cloning full-length IHHNV genome sequences is still lacking, which makes it difficult to study the genomics and molecular epidemiology of IHHNV. Here, a novel and rapid PCR technique was developed to determine the complete genomic sequences of IHHNV. The IHHNV genome was amplified in two overlapping fragments which each yielded a 2kb PCR product covering the first half or the second half of IHHNV genome, respectively. Using this method, six complete genomic sequences of IHHNV, which were collected from different regions of Zhejiang province in China, were cloned and sequenced successfully. The new cloning method will greatly facilitate the study on the genomics and molecular epidemiology of IHHNV.


Assuntos
Clonagem Molecular , Densovirinae/genética , Genoma Viral , Reação em Cadeia da Polimerase/métodos , Animais , China , Análise por Conglomerados , Densovirinae/classificação , Densovirinae/isolamento & purificação , Dados de Sequência Molecular , Penaeidae/virologia , Filogenia , Análise de Sequência de DNA , Homologia de Sequência , Fatores de Tempo
20.
JACC Cardiovasc Imaging ; 8(8): 888-96, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26189118

RESUMO

OBJECTIVES: The purpose of this study was to assess the potential of iterative image reconstruction (IR) of images for radiation dose reduction in coronary computed tomography angiography (CTA). Therefore, IR in combination with 30% tube current reduction was compared with standard scanning with filtered back projection (FBP) reconstruction. BACKGROUND: Lately, new IR techniques with advanced raw data processing have been introduced by different computed tomography vendors, thus allowing for either image noise reduction at unchanged radiation dose levels or radiation dose reductions at comparable image noise levels. METHODS: In this prospective, multicenter, multivendor noninferiority trial, we randomized 400 consecutive patients to 1 of 2 groups: a control group using standard FBP image reconstruction and standard tube current or an interventional group using IR technique and 30% tube current reduction. The primary endpoint was to demonstrate noninferiority in image quality (IQ) in the IR group. IQ was assessed on a 4-point scale (1, nondiagnostic IQ; 4, excellent IQ). Secondary endpoints included total radiation dose estimates and the rate of downstream testing during 30-day follow-up. RESULTS: Median IQ in the IR group was noninferior compared with the conventional FBP group (IR, 3.5 [interquartile range: 3.0 to 4.0]; FBP, 3.4 [interquartile range: 2.8 to 4.0], p for noninferiority <0.016). The radiation exposure was significantly lower in the IR group (median dose-length-product 157 [interquartile range: 114 to 239] mGy·cm vs. 222 [interquartile range: 141 to 319] mGy·cm for IR vs. FBP, respectively, p < 0.0001). The rate of downstream testing did not differ significantly (7.7% vs. 7.9% for IR vs. FBP, respectively, p = 0.94). CONCLUSIONS: Coronary CTA image quality is maintained with the combined use of a 30% reduced tube current and IR algorithms when compared with conventional FBP image reconstruction techniques and standard tube current. (Prospective Randomized Trial On RadiaTion Dose Estimates Of CT AngIOgraphy In PatieNts: NCT01453712).


Assuntos
Angiografia Coronária , Processamento de Imagem Assistida por Computador , Doses de Radiação , Tomografia Computadorizada por Raios X , Algoritmos , Densovirinae , Estudos Prospectivos
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