| genome-based detection methods of macrobrachium rosenbergii nodavirus, a pathogen of the giant freshwater prawn, macrobrachium rosenbergii dot-blot, in situ hybridization and rt-pcr. | the availability of specific and rapid detection methods is essential for monitoring the health status of farmed species, particularly in viral diseases as in this case early diagnosis is a critical factor in containing disease outbreaks. three complementary genome-based methods were developed for the detection of macrobrachium rosenbergii nodavirus (mrnv), i.e. dot-blot hybridization, in situ hybridization and reverse transcriptase-polymerase chain reaction (rt-pcr). detection limits were estab ... | 2003 | 14653316 |
| characteristics of the monocistronic genome of extra small virus, a virus-like particle associated with macrobrachium rosenbergii nodavirus: possible candidate for a new species of satellite virus. | white tail disease (wtd) causes a high mortality rate in the freshwater prawn macrobrachium rosenbergii. the pathogenic agent is a small virus, 25 nm in diameter, macrobrachium rosenbergii nodavirus (mrnv), associated with extra small virus (xsv), a virus-like particle,15 nm in diameter. sequencing of the xsv genome showed that it consists of a linear single-stranded rna of 796 nucleotides, encoding a single structural protein, the capsid cp-17. the genome is in sense orientation, ended by a sho ... | 2004 | 14993649 |
| experimental transmission and tissue tropism of macrobrachium rosenbergii nodavirus (mrnv) and its associated extra small virus (xsv). | white tail disease (wtd) was found to be a serious problem in hatcheries and nursery ponds of macrobrachium rosenbergii in india. the causative organisms have been identified as m. rosenbergii nodavirus (mrnv) and its associated extra small virus (xsv). experimentally transmitted to healthy animals, they caused 100% mortality in post-larvae but failed to cause mortality in adult prawns. the rt-pcr assay revealed the presence of both viruses in moribund post-larvae and in gill tissue, head muscle ... | 2004 | 15672874 |
| simultaneous detection of macrobrachium rosenbergii nodavirus and extra small virus by a single tube, one-step multiplex rt-pcr assay. | post-larvae of macrobrachium rosenbergii infected with white tail disease were collected from hatcheries and nursery ponds in india. the causative organisms have been identified as macrobrachium rosenbergii nodavirus (mrnv) and extra small virus (xsv). a one-step multiplex reverse transcriptase-polymerase chain reaction (rt-pcr) has been developed to detect these viruses simultaneously in naturally and experimentally infected prawns. several parameters were assayed in order to optimize the proto ... | 2005 | 15705151 |
| rapid detection of macrobrachium rosenbergii nodavirus (mrnv) and extra small virus (xsv), the pathogenic agents of white tail disease of macrobrachium rosenbergii (de man), by loop-mediated isothermal amplification. | a loop-mediated isothermal amplification (lamp) procedure is described for rapid diagnosis of white tail disease, a viral disease caused by macrobrachium rosenbergii nodavirus (mrnv) and extra small virus (xsv), in the giant freshwater prawn, macrobrachium rosenbergii. this method was more sensitive than conventional rt-pcr for detecting the two viruses. a set of four primers, two outer and two inner, were designed for mrnv detection. an additional pair of loop primers was also used in an accele ... | 2006 | 16677317 |
| artemia as a possible vector for macrobrachium rosenbergii nodavirus (mrnv) and extra small virus transmission (xsv) to macrobrachium rosenbergii post-larvae. | five developmental stages of artemia were exposed to macrobrachium rosenbergii nodavirus (mrnv) and extra small virus (xsv) by immersion and oral routes in order to investigate the possibility of artemia acting as a reservoir or carrier of these viruses. the second objective was to determine if virus-exposed artemia were capable of transmitting the disease to post-larvae (pl) of m. rosenbergii. there was no significant difference in percent mortality between artemia control groups and groups cha ... | 2006 | 16875403 |
| quantitative relationship of two viruses (mrnv and xsv) in white-tail disease of macrobrachium rosenbergii. | macrobrachium rosenbergii nodavirus (mrnv) and extra small virus (xsv) were purified from diseased freshwater prawns m. rosenbergii and used to infect healthy post-larvae (pl) by an immersion method. three groups of prawns were challenged with various combined doses of mrnv and xsv. signs of white-tail disease (wtd) were observed in groups 1 and 2, which had been challenged with combinations containing relatively high proportions of mrnv and low proportions of xsv. by contrast there was little s ... | 2006 | 16921996 |
| in situ hybridization and rt-pcr detection of macrobrachium rosenbergii nodavirus in giant freshwater prawn, macrobrachium rosenbergii (de man), in taiwan. | between january and march 2006, suspected outbreaks of white tail disease were observed in post-larvae and juveniles of macrobrachium rosenbergii in hatcheries and nursery ponds at kaohsiung and pingtung counties in southern taiwan. pathognomonic lesions showed the presence of large oval and/or irregular basophilic, cytoplasmic inclusion bodies in the infected muscles and hepatopancreas. reverse transcriptase polymerase chain reaction (rt-pcr) assay and in situ hybridization (ish) revealed evide ... | 2006 | 17169113 |
| experimental vertical transmission of macrobrachium rosenbergii nodavirus (mrnv) and extra small virus (xsv) from brooders to progeny in macrobrachium rosenbergii and artemia. | white tail disease (wtd) is a serious problem in hatcheries and nursery ponds of macrobrachium rosenbergii in india. experiments were carried out to determine the possibility of vertical transmission of m. rosenbergii nodavirus (mrnv) and extra small virus (xsv) in m. rosenbergii and artemia. prawn broodstock inoculated with mrnv and xsv by oral or immersion challenge survived without any clinical signs of wtd. the brooders spawned 5-7 days after inoculation and the eggs hatched. the survival ra ... | 2007 | 17241402 |
| development of in situ hybridization and rt-pcr assay for the detection of a nodavirus (pvnv) that causes muscle necrosis in penaeus vannamei. | a nodavirus (tentatively named pvnv, penaeus vannamei nodavirus) that causes muscle necrosis in p. vannamei was found in belize in 2004. from 2004 to 2006, shrimp samples collected from belize exhibited clinical signs, white, opaque lesions in the tails and histopathology similar to those of shrimps infected by infectious myonecrosis virus (imnv). histological examination revealed multifocal necrosis and hemocytic fibrosis in the skeletal muscle. in addition, basophilic, cytoplasmic inclusions w ... | 2007 | 17629112 |
| in vitro replication of macrobrachium rosenbergii nodavirus and extra small virus in c6/36 mosquito cell line. | white tail disease (wtd) is a serious problem in hatcheries and nursery ponds of macrobrachium rosenbergii in india and many parts of the world. the pathogenic agents have been identified as m. rosenbergii nodavirus (mrnv) associated with extra small virus (xsv), which is 27nm and 15nm in diameter, respectively. replication of mrnv and xsv was investigated in apparently healthy c6/36 subclone of aedes albopictus cell line. the results revealed that c6/36 cells were susceptible to these viruses. ... | 2007 | 17651820 |
| cloning and sequencing of capsid protein of indian isolate of extra small virus from macrobrachium rosenbergii. | white tail disease (wtd) is found to cause immense economic losses in hatcheries and farms, with mortalities often reaching 100% within 2 or 3 days. the pathogenic agents have been identified as macrobrachium rosenbergii nodavirus (mrnv) associated with extra small virus (xsv), which are 27 and 15 nm in diameter, respectively. experiments were carried out to characterize an indian isolate of xsv capsid protein of 17 kda (cp-17). the gene encoding cp-17 was cloned and its sequence analysed with s ... | 2008 | 17928085 |
| partial susceptibility of the ssn-1 fish cell line to a crustacean virus: a defective replication study. | this study evaluated the possible use of the fish ssn-1 cell line to investigate the development of macrobrachium rosenbergii nodavirus (mrnv). cells were incubated with viral particles and cytopathic effects were observed. de novo synthesis of viral capsid proteins was shown by immuno-fluorescence labelling and a sandwich elisa test. viral genomic replication was demonstrated by rt-pcr using primers specific to rna-1 as well as by quantitative rt-pcr (rt-qpcr). using electron microscopy, only a ... | 2007 | 17958611 |
| macrobrachium rosenbergii nodavirus infection in m. rosenbergii (de man) with white tail disease cultured in taiwan. | white tail disease (wtd) is a serious problem in macrobrachium rosenbergii hatcheries and nursery ponds in asia. the causative agents have been identified as m. rosenbergii nodavirus (mrnv) and its associated extra small virus. this is the first report demonstrating mrnv virus in m. rosenbergii displaying wtd signs in taiwan by reverse transcriptase-polymerase chain reaction (rt-pcr). amplified fragments of 850 and 425 bp for rna-1 and rna-2 of mrnv, respectively, were obtained by rt-pcr. rt-pcr ... | 2008 | 18471097 |
| natural aquatic insect carriers of macrobrachium rosenbergii nodavirus (mrnv) and extra small virus (xsv). | five different species of aquatic insects were collected from nursery ponds containing the freshwater prawn macrobrachium rosenbergii infected with macrobrachium rosenbergii nodavirus (mrnv) and extra small virus (xsv). the insects were screened as potential natural carriers of mrnv and xsv. rt-pcr (reverse transcription polymerase chain reaction) analysis gave positive results for mrnv and xsv in belostoma sp., aesohna sp., cybister sp. and notonecta sp., and negative results for nepa sp. an ae ... | 2008 | 18500030 |
| detection of shrimp infectious myonecrosis virus by reverse transcription loop-mediated isothermal amplification combined with a lateral flow dipstick. | infectious myonecrosis virus (imnv) has caused a slowly progressive disease with cumulative mortalities of up to 70% or more in cultured penaeus (litopenaeus) vannamei in northeast brazil and indonesia. rapid detection of viruses by loop-mediated isothermal amplification (lamp) of genomic material with high specificity and sensitivity can be applied for diagnosis, monitoring and control of diseases in shrimp aquaculture. using an imnv template, successful detection was achieved after a 60-min rt ... | 2009 | 19022295 |
| macrobrachium rosenbergii nodavirus disease (white tail disease) in australia. | the index case of white tail disease (wtd) is presented in adult broodstock prawns macrobrachium rosenbergii from the flinders river in western queensland, australia, in mid-2007. histological examination revealed extensive myonecrosis with massive infiltration of myonuclei and some haemocytes. juveniles from the same broodstock but not from 3 other families displayed white muscle lesions. low-grade chronic mortalities approaching 100% over 1 yr occurred. reverse transcriptase polymerase chain r ... | 2009 | 19750804 |
| clearance of macrobrachium rosenbergii nodavirus (mrnv) and extra small virus (xsv) and immunological changes in experimentally injected macrobrachium rosenbergii. | macrobrachium rosenbergii was experimentally challenged with macrobrachium rosenbergii nodavirus (mrnv) and extra small virus (xsv) to study the clearance of these viruses and consequent changes in various immunological parameters. the healthy animals were injected mrnv and xsv intramuscularly and various organ samples such as gill tissue, head soft tissue, pleopods and intestine were collected at different time intervals of 3, 5, 10, 15, 25, 50, 75 and 100d post-infection (p.i.) to study the vi ... | 2010 | 19963067 |
| application of high resolution melt (hrm) analysis for duplex detection of macrobrachium rosenbergii nodavirus (mrnv) and extra small virus (xsv) in shrimp. | in this work, a probe-free, multiplex rt-pcr was combined with high resolution melt (hrm) analysis for the simultaneous detection of macrobrachium rosenbergii nodavirus (mrnv) and extra small virus (xsv) infection in the freshwater prawn macrobrachium rosenbergii. this first application of hrm multiplex rt-pcr in shrimp reveals a new potential for rapid and sensitive detection of multiple pathogens. in addition, sequence variation in xsv could be observed from the high resolution melt peaks, as ... | 2010 | 20600824 |
| rapid and sensitive detection of macrobrachium rosenbergii nodavirus in giant freshwater prawns by reverse transcription loop-mediated isothermal amplification combined with a lateral flow dipstick. | loop-mediated isothermal amplification (lamp) allows rapid amplification of nucleic acids under isothermal conditions. it can be combined with a chromatographic lateral flow dipstick (lfd) for much more efficient, field-friendly detection of mrnv. in this work, rt-lamp was performed at 65 degrees c for 40 min, followed by 5 min for hybridization with an fitc-labeled dna probe and 5 min for lfd resulted in visualization of dna amplicons trapped at the lfd test line. thus, total assay time, includ ... | 2010 | 20655379 |
| shrimp laminin receptor binds with capsid proteins of two additional shrimp rna viruses yhv and imnv. | laminin receptor (lamr) in shrimp was previously proposed to be a potential receptor protein for taura syndrome virus (tsv) based on yeast two-hybrid assays. since shrimp lamr bound to the vp1 capsid protein of tsv, we were interested to know whether capsid/envelope proteins from other shrimp viruses would also bind to lamr. thus, capsid/envelope encoding genes from 5 additional shrimp viruses were examined. these were penaeus stylirostris densovirus (pstdnv), white spot syndrome virus (wssv), i ... | 2011 | 21414409 |
| virus-like particles of macrobrachium rosenbergii nodavirus produced in bacteria. | macrobrachium rosenbergii nodavirus (mrnv) infects giant freshwater prawns and causes white tail disease (wtd). the coding region of the capsid protein of mrnv was amplified with rt-pcr and cloned into the ptrchis2-topo vector. the recombinant plasmid was introduced into escherichia coli and protein expression was induced with iptg. sds-page showed that the recombinant protein containing the his-tag and myc epitope has a molecular mass of about 46kda and it was detected by the anti-his antibody ... | 2011 | 21536072 |
| ultrastructural and sequence characterization of penaeus vannamei nodavirus (pvnv) from belize. | the penaeus vannamei nodavirus (pvnv), which causes muscle necrosis in penaeus vannamei from belize, was identified in 2005. infected shrimp show clinical signs of white, opaque lesions in the tail muscle. under transmission electron microscopy, the infected cells exhibit increases in various organelles, including mitochondria, golgi stacks, and rough endoplasmic reticulum. cytoplasmic inclusions containing para-crystalline arrays of virions were visualized. the viral particle is spherical in sh ... | 2011 | 21790065 |