scholarly journals Evidence for insect transmission of rabbit haemorrhagic disease virus

2002 ◽  
Vol 129 (3) ◽  
pp. 655-663 ◽  
Author(s):  
K. A. McCOLL ◽  
J. C. MERCHANT ◽  
J. HARDY ◽  
B. D. COOKE ◽  
A. ROBINSON ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Infectious Virus ◽  
Fold Increase ◽  
Field Trials ◽  
Rabbit Haemorrhagic Disease Virus ◽  
Chain Reaction ◽  
Rabbit Haemorrhagic Disease ◽  
Insect Populations ◽  
Polymerase Chain ◽  
Haemorrhagic Disease

The spread of rabbit haemorrhagic disease (RHD) virus from quarantine on Wardang Island to mainland Australia in 1995 suggested that insects could be potential vectors. Field observations and laboratory experiments were conducted to address aspects of this hypothesis. Firstly, the variation in insect populations on the island during the field trials was examined. There was approximately a 1000-fold increase in the number of bushflies, Musca vetustissima, shortly before the spread of the virus. Secondly, M. vetustissima were tested in the laboratory as potential vectors of RHD virus, and it was demonstrated that disease could be transmitted between rabbits by flies. Finally, 13 of 16 insect samples, collected from Wardang Island and from several sites on the mainland following the spread of virus off the island, were positive for the presence of RHD virus by a specific polymerase chain reaction (PCR). Only one sample contained sufficient infectious virus to kill a susceptible rabbit. These data, combined with previously published information on fly biology, suggested that flies, particularly bushflies, may be involved in the transmission of RHD virus. Other possible routes of spread were not assessed in this study.

Detection of RNA of rabbit haemorrhagic disease virus from New Zealand wild rabbits

2002 ◽  
Vol 29 (6) ◽  
pp. 683 ◽  
Author(s):  
Tao Zheng ◽  
Anna M. Napier ◽  
John P. Parkes ◽  
Joseph S. O'Keefe ◽  
Paul H. Atkinson
Keyword(s):  
New Zealand ◽  
Disease Virus ◽  
Rabbit Haemorrhagic Disease Virus ◽  
Rt Pcr ◽  
Specific Primers ◽  
Tissue Samples ◽  
Wild Isolate ◽  
Rabbit Haemorrhagic Disease ◽  
Polymerase Chain ◽  
Haemorrhagic Disease

Rabbit numbers have returned to high levels in some areas of New Zealand following the initial spread of rabbit haemorrhagic disease virus (RHDV). We undertook to determine whether possible infection with an RHDV-related virus was interfering with the initiation of new outbreaks of rabbit haemorrhagic disease (RHD). RHDV RNA was detected by polymerase chain reaction with reverse transcription (RT-PCR) using RHDV-specific primers from tissue samples of wild rabbits that had been shot in the field. RHDV RNA was detected in 11 of 19 rabbits from an area of Otago where the rabbit population had greatly expanded and in 2 of 8 rabbits from the West Coast where outbreaks of RHD had not been previously reported. Among the 13 rabbits positive for RHDV RNA, 10 had detectable antibodies against RHDV. The nucleotide sequences of the isolates — a segment of the RHDV capsid gene — shared about 99% identity with that of the Czech strain V351 and that of a 1997 New Zealand wild isolate, but shared only about 84% identity with that of a European benign rabbit calicivirus. These results provide evidence for persistent infection of RHDV in rabbits.

scholarly journals The emergence of rabbit haemorrhagic disease virus: will a non-pathogenic strain protect the UK?

2001 ◽  
Vol 356 (1411) ◽  
pp. 1087-1095 ◽  
Author(s):  
P.J. White ◽  
R.A. Norman ◽  
R.C. Trout ◽  
E.A. Gould ◽  
P.J. Hudson
Keyword(s):  
Disease Virus ◽  
Pathogenic Strain ◽  
Rabbit Haemorrhagic Disease Virus ◽  
Rabbit Haemorrhagic Disease ◽  
Seroprevalence Data ◽  
Age Structured ◽  
Reproductive Rates ◽  
The Uk ◽  
Haemorrhagic Disease ◽  
Age Structured Model

Rabbit haemorrhagic disease virus emerged in China in 1984, and has killed hundreds of millions of wild rabbits in Australia and Europe. In the UK there appears to be an endemic non–pathogenic strain, with high levels of seroprevalence being recorded, in the absence of associated mortality. Using a seasonal, age–structured model we examine the hypothesis that differences in rabbit population demography differentially affect the basic reproductive rates ( R 0 ) of the pathogenic and non–pathogenic strains, leading to each dominating in some populations and not others. The strain with the higher R 0 excluded the other, with the dynamics depending upon the ratio of the two R 0 values. When the non–pathogenic strain dominated, the pathogenic strain caused only transient mortality, although this could be significant when the two R 0 values were similar. When the pathogenic strain dominated, repeated epidemics led to host eradication. Seroprevalence data suggest that the non–pathogenic strain may be protecting some, but not all UK populations, with half being ‘at risk’ from invasion by the pathogenic strain and a fifth prone to significant transient mortality. We identify key questions for empirical research to test this prediction.

Distribution of Rabbit Haemorrhagic Disease Virus RNA in Experimentally Infected Rabbits

2001 ◽  
Vol 124 (2-3) ◽  
pp. 134-141 ◽  
Author(s):  
T. Kimura ◽  
I. Mitsui ◽  
Y. Okada ◽  
T. Furuya ◽  
K. Ochiai ◽  
...  
Keyword(s):  
Disease Virus ◽  
Rabbit Haemorrhagic Disease Virus ◽  
Virus Rna ◽  
Rabbit Haemorrhagic Disease ◽  
Haemorrhagic Disease

Persistence of Hepatitis A Virus in Oysters†

2003 ◽  
Vol 66 (2) ◽  
pp. 331-334 ◽  
Author(s):  
DAVID H. KINGSLEY ◽  
GARY P. RICHARDS
Keyword(s):  
Polymerase Chain Reaction ◽  
Crassostrea Virginica ◽  
Reverse Transcription ◽  
Hepatitis A ◽  
Infectious Virus ◽  
Hepatitis A Virus ◽  
Complete Removal ◽  
Chain Reaction ◽  
Daily Feeding ◽  
Polymerase Chain

We investigated the ability of hepatitis A virus (HAV) to persist for up to 6 weeks in Eastern oysters (Crassostrea virginica). Viral RNA was detected by reverse transcription–polymerase chain reaction 6 weeks after 16 h of exposure to 90,000 PFU (180 PFU/ml of seawater) of HAV. Assaying for infectious virus in oysters that received a daily feeding of phytoplankton recovered 3,800, 650, and 500 PFU of HAV 1, 2, and 3 weeks after contamination with 90,000 PFU of HAV, respectively. However, no infectious HAV was isolated from oysters 4, 5, or 6 weeks after contamination. These results support the position that shellfish depuration is insufficient for the complete removal of infectious viruses. Extended relay times (in excess of 4 weeks) may be required to produce virologically safe shellfish.

scholarly journals Molecular epidemiology of Rabbit haemorrhagic disease virus

2002 ◽  
Vol 83 (10) ◽  
pp. 2461-2467 ◽  
Author(s):  
S. R. Moss ◽  
S. L. Turner ◽  
R. C. Trout ◽  
P. J. White ◽  
P. J. Hudson ◽  
...  
Keyword(s):  
Disease Virus ◽  
Nucleotide Sequencing ◽  
Molecular Evidence ◽  
Rabbit Haemorrhagic Disease Virus ◽  
Rabbit Haemorrhagic Disease ◽  
Molecular Phylogenetic ◽  
Virulent Virus ◽  
Rabbit Bone ◽  
European Rabbits ◽  
Haemorrhagic Disease

Millions of domestic and wild European rabbits (Oryctolagus cuniculus) have died in Europe, Asia, Australia and New Zealand during the past 17 years following infection by Rabbit haemorrhagic disease virus (RHDV). This highly contagious and deadly disease was first identified in China in 1984. Epidemics of RHDV then radiated across Europe until the virus apparently appeared in Britain in 1992. However, this concept of radiation of a new and virulent virus from China is not entirely consistent with serological and molecular evidence. This study shows, using RT–PCR and nucleotide sequencing of RNA obtained from the serum of healthy rabbits stored at 4 °C for nearly 50 years, that, contrary to previous opinions, RHDV circulated as an apparently avirulent virus throughout Britain more than 50 years ago and more than 30 years before the disease itself was identified. Based on molecular phylogenetic analysis of British and European RHDV sequences, it is concluded that RHDV has almost certainly circulated harmlessly in Britain and Europe for centuries rather than decades. Moreover, analysis of partial capsid sequences did not reveal significant differences between RHDV isolates that came from either healthy rabbits or animals that had died with typical haemorrhagic disease. The high stability of RHDV RNA is also demonstrated by showing that it can be amplified and sequenced from rabbit bone marrow samples collected at least 7 weeks after the animal has died.

scholarly journals Potentially a new subtype of the cytoplasmic male sterility S- type in maize

Genetika ◽  
2013 ◽  
Vol 45 (1) ◽  
pp. 145-151
Author(s):  
Jelena Vancetovic ◽  
Dragana Ignjatovic-Micic ◽  
Ana Nikolic ◽  
Sofija Bozinovic ◽  
Ksenija Markovic ◽  
...  
Keyword(s):  
Cytoplasmic Male Sterility ◽  
Male Sterility ◽  
Multiplex Polymerase Chain Reaction ◽  
Laboratory Experiments ◽  
Gene Bank ◽  
Chain Reaction ◽  
Additional Band ◽  
Two Samples ◽  
Polymerase Chain ◽  
Maize Research Institute

In gene-bank maize collection of Maize Research Institute Zemun Polje (MRI) two samples with untypical mtDNA profile for cytoplasmic male sterility (cms) were identified. These two samples showed typical multiplex polymerase chain reaction (PCR) band for cms-S, but also an additional band of unknown nature. It is assumed that the additional band is the result of a rearrangement of the two mitochondrial episomes characteristic for the cms-S in maize or a duplication of the part of cms-S mitochondrial genome. Additional field and laboratory experiments are necessary in the further lightening of this phenomenon.

Sign in / Sign up

Export Citation Format

Share Document