Kashmir Bee Virus: Difference between revisions

From MicrobeWiki, the student-edited microbiology resource
Line 30: Line 30:


==Viral Ecology & Pathology==
==Viral Ecology & Pathology==
<br>
<br>KBV is known to infect many species of bees across a large geographic distribution. Cases of A. melifera infection have been reported worldwide, although cases involved in CCD have only been reported in the US. KBV is also known to infect A. cerana (Asiatic honey bee) in parts of Southeast Asia and India, where the virus is believed to have originated. KBV has also been reported in populations of Bombus spp. (bumble bees) in New Zealand and Vespula germanica (European wasp) in Australia. [5]


==References==
==References==

Revision as of 19:59, 14 September 2008

A Viral Biorealm page on the family Kashmir Bee Virus

Baltimore Classification


Group IV: (+) sense single-stranded RNA viruses

Higher order categories


Order: Picornavirales
Family: Dicistroviridae
Genus: Cripavirus

Description and Significance


Kashmir bee virus (KBV) infects many types of bees including Apis mellifera, the European honey bee [5]. The virus effects both brood and adult bees. Infected adults die within a few days of exposure to the virus but infected larvae may survive and develop into seemingly unaffected adults [2]. While Kashmir bee virus infection alone may not be of much significance, it has been implicated as part of a much larger agricultural issue.

A. mellifera is the species of bee used in the US for crop pollination and commercial honey production. In 2000, an estimated $14.6 of US crops were pollinated by A. mellifera [7]. However, recently, many A. mellifera colonies have been disappearing due to a phenomenon known as Colony Collapse Disorder (CCD) [1]. In the spring of 2007, beekeepers across the US reported loss of up to 80-100% of their bee colonies. Although it is unclear exactly what causes CCD, a group of related bee viruses including KBV have been implicated [7]. It seems as if these viruses interact with parasitic mite infestations and other environmental factors to cause CCD. A better understanding of KBV and other bee viruses could aid in the control and prevention of CCD, rescuing the US from a potential agricultural crisis.

Genome Structure


The KBV genome is composed of (+) sense ssRNA and is 9506 nt in length. The genome contains two open reading frames each coding for a polyprotein. These ORFs are separated by and intergenic region and flanked with short non coding regions. [5]

The 5’ ORF codes the non-structural polyprotein which includes three helicase domains, a 3C-protease domain, and 8 RNA polymerase domains (including and RNA-dependent RNA polymerase). The 3’ ORF codes for the structural polyprotein which contains two picornavirus-like capsid protein domains. [5]

Virion Structure of Kashmir bee virus


The KBV virion consists of a non-enveloped, icosohedral capsid. The capsid is constructed from 3 structural proteins [4]. The capsid appears round and is approximately 30 nm in width [7].

Reproductive Cycle of a ______virus in a Host Cell


Viral Ecology & Pathology


KBV is known to infect many species of bees across a large geographic distribution. Cases of A. melifera infection have been reported worldwide, although cases involved in CCD have only been reported in the US. KBV is also known to infect A. cerana (Asiatic honey bee) in parts of Southeast Asia and India, where the virus is believed to have originated. KBV has also been reported in populations of Bombus spp. (bumble bees) in New Zealand and Vespula germanica (European wasp) in Australia. [5]

References

[1] Arduengo, Michele. “A Stinging Decline: Declining Pollinator Populations.” Promega Corporation <www.promega.com/enotes/features/fe0029.htm>

[2] Berenyi, O., T. Bakonyi, I. Derakhshifar, H. Koglberger, N. Nowotny. “Occurrence of Six Honeybee Viruses in Diseased Australian Apiaries.” Applied and Environmental Microbiology 72.4 (2006): 2412-2420.

[3] Chen, Y.P., J.S. Pettis, A. Collins, M.F. Feldaufer. “Prevalence and Transmission of Honeybee Viruses.” Applied and Environmental Microbiology 72.1 (2006): 606-611.

[4] “Cripavirus.” ICTVdB Descriptions <www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/00.101.0.01.htm>

[5] de Miranda, J.R., M. Drebot, S. Tyler, M. Shen, C.E. Cameron, D.B. Stoltz, S.M. Camazine. “Complete nucleotide sequence of Kashmir bee virus and comparison with acute bee paralysis.” Journal of General Virology 85 (2004): 2263-2270.

[6] “Kashmir bee virus.” NCBI Taxonomy browser <www.ncbi.nlm.nih.gov/Taxonomy/Browser>

[7] Oldroyd, Benjamin P. “Unsolved Mystery: What’s Killing American Honey Bees?” PLoS Biology 5.6 (2007).

[7] Shen, M., L. Cui, N. Ostiguy, D. Cox-Foster. “Intricate transmission routes and interactions between picorna-like viruses (Kashmir bee virus and sacbrood virus) with the honeybee host and the parasitic varroa mite.” Journal of General Virology 86 (2005): 2281-2289.

[8] Slonczewski, J.L., J.W. Foster. “Chapter 6: Virus Structure and Function.” Microbiology: An Evolving Science (2009): 181-217.

Page authored for BIOL 375 Virology, September 2008