scholarly journals Emergence of Reassortment between a New and Reported Types of Betanodavirus in Shellfish

Pathogens ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1232
Author(s):  
Young Chul Kim ◽  
Joon Gyu Min ◽  
Kwang Il Kim ◽  
Hyun Do Jeong
Keyword(s):  
The Body ◽  
Nervous Necrosis Virus ◽  
Rt Pcr ◽  
Necrosis Virus ◽  
Viral Particles ◽  
First Results ◽  
High Sequence Homology ◽  
Polymerase Chain ◽  
Epinephelus Septemfasciatus ◽  
Reference Strains

Recently, three types of betanodavirus including red spotted grouper nervous necrosis virus (RGNNV), barfin flounder nervous necrosis virus (BFNNV), and Korean shellfish nervous necrosis virus (KSNNV) (proposed as a new fifth type) have been detected in shellfish in the marine environment around Korea. To investigate the presence of reassortment between betanodavirus types, the type based on the RNA2 segment of betanodaviruses carried in 420 domestic shellfish (n = 306) and finfish (n = 35), as well as imported shellfish (n = 79), was compared with the type identified by reverse-transcriptase polymerase chain reaction (RT-PCR) for RNA1 segment. Only five samples carrying reassortant betanodaviruses were found, appearing as RG/KSNNV (n = 2), KS/RGNNV (n = 1), and SJ/RGNNV (n = 2) types. From these samples, we successfully isolated two reassortant strains from Korean and Chinese shellfish in E-11 cells and called them KG1-reKS/RG and CM1-reRG/KS, respectively. In the full genome sequences, each RNA segment of the reassortant strains exhibited the same gene length and high sequence homology (≥98%) with the reference strains corresponding to the type of each segment. Both these reassortant strains induced high mortality to sevenband grouper (Epinephelus septemfasciatus) larvae with high viral concentrations in the body (109 viral particles/mg) and severe vacuolation in the retina and brain. These are the first results showing the involvement of the KSNNV type in the reassortment of RNA segments in the reported types of betanodavirus, which could represent a new potential risk in fish.

scholarly journals Detection of Bluetongue Virus Serogroup by Polymerase Chain Reaction

1992 ◽  
Vol 4 (4) ◽  
pp. 400-405 ◽  
Author(s):  
Geoffrey Y. Akita ◽  
Jarasvech Chinsangaram ◽  
Bennie I. Osburn ◽  
Marius Ianconescu ◽  
Rozalia Kaufman
Keyword(s):  
Polymerase Chain Reaction ◽  
Bluetongue Virus ◽  
Wide Spectrum ◽  
Genome Segment ◽  
Clinical Samples ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Field Isolates ◽  
Viral Particles ◽  
Polymerase Chain

To facilitate detection of active bluetongue virus (BTV) infection, a polymerase chain reaction (PCR) protocol was developed. The BTV reverse transcriptase PCR (RT-PCR) is a 1-tube reaction and involves chemical denaturation of the double-stranded viral RNA target, a complementary DNA (cDNA) synthesis step, and PCR amplification of the cDNA. BTV RT-PCR using primers derived from highly conserved genome segment 10 results in a 251–base pair (bp) product. BTV RNA from all USA prototype serotypes 2, 10, 11, 13, and 17; a wide spectrum of USA BTV field isolates including serotypes 10, 11, 13, and 17; and a spectrum of Israeli field isolates including serotypes 2, 4, 6, 10, and 16 were detected by BTV RT-PCR. With agarose gels, the 251–bp product was detected from as little as 100 fg-1 pg of BTV RNA, which is equivalent to 5 × 103-5 × 104 viral particles or 5 × 102-5 × 103 infectious units. With dot blot hybridization, specific PCR product was detected from as little as 1 fg of BTV RNA, which is equivalent to 50 viral particles, or 5 infectious units. This level of sensitivity is comparable to that of virus isolation. The BTV RT-PCR using primers derived from genome segment 10 can detect a wide spectrum of USA and Israeli BTV serotypes and has potential for detection of infection by the BTV serogroup. Application of this BTV PCR to clinical samples is in progress.

scholarly journals Detection of nervous necrosis virus using RT-PCR combined with tissue culture.

2002 ◽  
Vol 68 (2) ◽  
pp. 197-200
Author(s):  
KEN-ICHI WATANABE ◽  
MAMORU YOSHIMIZU
Keyword(s):  
Tissue Culture ◽  
Nervous Necrosis Virus ◽  
Rt Pcr ◽  
Necrosis Virus

Required dose of fish nervous necrosis virus (NNV) for Poly(I:C) immunization of sevenband grouper Epinephelus septemfasciatus

Aquaculture ◽  
2011 ◽  
Vol 311 (1-4) ◽  
pp. 100-104 ◽  
Author(s):  
Toyohiko Nishizawa ◽  
Ikuo Takami ◽  
Mamoru Yoshimizu ◽  
Myung-Joo Oh
Keyword(s):  
Poly I:C ◽  
Nervous Necrosis Virus ◽  
Necrosis Virus ◽  
Epinephelus Septemfasciatus

scholarly journals Immune Response of Senegalese Sole against Betanodavirus Mutants with Modified Virulence

Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1388
Author(s):  
Juan Gémez-Mata ◽  
Sandra Souto ◽  
Isabel Bandín ◽  
María del Carmen Alonso ◽  
Juan José Borrego ◽  
...  
Keyword(s):  
Immune Response ◽  
Nervous Necrosis Virus ◽  
Senegalese Sole ◽  
Coding Region ◽  
Necrosis Virus ◽  
A Genome ◽  
Positive Sense ◽  
The Complement System ◽  
Reference Strains ◽  
Viral Encephalopathy And Retinopathy

Nervous necrosis virus (NNV), genus Betanodavirus, the etiological agent of the viral encephalopathy and retinopathy (VER), presents a genome with two positive-sense single-stranded RNA segments. Striped jack nervous necrosis virus (SJNNV) and red-spotted grouper nervous necrosis virus (RGNNV), together with reassortants RGNNV/SJNNV, are the betanodaviruses predominantly isolated in Southern Europe. An RGNNV/SJNNV reassortant isolated from Senegalese sole (wt160) causes high mortalities in this fish species. This virus presents differences in the sequence of the 3’ non-coding region (NCR) of both segments compared to RGNNV and SJNNV reference strains. Previously, it has been reported that the reversion of two of these differences (nucleotides 1408 and 1412) in the RNA2 3’NCR to the SJNNV-type (recombinant r1408-1412) resulted in a decrease in sole mortality. In the present study, we have applied an OpenArray® to analyse the involvement of sole immune response in the virulence of several recombinants: the r1408-1412 and two recombinants, developed in the present study, harbouring mutations at positions 3073 and 3093 of RNA1 3’NCR to revert them to RGNNV-type. According to the correlation values and to the number of expressed genes, the infection with the RNA2-mutant provoked the most different immune response compared to the immune response triggered after the infection with the rest of the viruses, and the exclusive and high upregulation of genes related to the complement system. The infection with the RNA1-mutants also provoked a decrease in mortality and their replication was delayed at least 24 h compared to the wt160 replication, which could provoke the lag observed in the immune response. Furthermore, the infection with the RNA1-mutants provoked the exclusive expression of pkr and the downregulation of il17rc.

scholarly journals Detection of enteroviruses in cases of neurological disorders in the State of Pará, Brazil

2001 ◽  
Vol 43 (6) ◽  
pp. 321-324 ◽  
Author(s):  
Maria de Lourdes Contente GOMES ◽  
Helena KOPECKA ◽  
Alexandre da Costa LINHARES
Keyword(s):  
Aseptic Meningitis ◽  
Deficiency Syndrome ◽  
Rt Pcr ◽  
Specific Primers ◽  
Newborn Mice ◽  
Negative Results ◽  
Viral Particles ◽  
Motor Deficiency ◽  
Virology Section ◽  
Polymerase Chain

Eighty-one cerebrospinal fluid (CSF) samples mainly from cases of aseptic meningitis and motor deficiency syndrome were sent to the Virology Section of Evandro Chagas Institute, Belém Pará, in the period of January 1995 to January 1996 in order to isolate viruses. All samples were inoculated onto HEp-2 cell culture and newborn mice, with negative results. The probability of isolating viruses by these methods is reduced because of the low concentration of viral particles in these specimens. In order to obtain more information about the etiology of these cases, a group of 23 samples were selected to be tested by a more sensitive technique than the virus isolation - the reverse transcription polymerase chain reaction (RT-PCR). Specific primers directed to conserved regions in the enterovirus genome were used, considering that this group of viruses is frequently associated with these neurological disorder. The age of the patients ranged from 1 to 55 years and nearly all of them lived in Belém, State of Pará, North of Brazil. Of 15 samples analyzed by RT PCR nine (60%) were positive; of these, 6 (66.6%) had motor deficiency and 3 (33.3%) developed aseptic meningitis. These results show that it is important to investigate enterovirus as cause of these syndromes.

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