TWiV 313: With viruses like these, who needs enemas?

On episode #313 of the science show This Week in Virology, Vincent, Alan, and Rich discuss how norovirus, an enteric virus, can replace the functions of the gut microbiome.

You can find TWiV #313 at www.microbe.tv/twiv.

TWiV 312: She sells B cells

On episode #312 of the science show This Week in Virology, the TWiVbolans discuss the finding that human noroviruses, major causes of gastroenteritis, can for the first time be propagated in B cell cultures, with the help of enteric bacteria.

You can find TWiV #312 at www.microbe.tv/twiv.

TWiV 285: Hokies go viral

On episode #285 of the science show This Week in Virology, Vincent meets up with XJ Meng and Sarah McDonald at Virginia Tech to talk about their work on viruses of swine and rotaviruses.

You can find TWiV #285 at www.microbe.tv/twiv.

TWiV 243: Live from ASV at Penn State

On this episode of the science show This Week in Virology, which was recorded before a large enthusiastic audience at the annual meeting of the American Society for Virology, Vincent, Rich, and Kathy speak with Rebecca and Christiane about their work on metapneumoviruses and noroviruses.

You can find TWiV #243 at www.microbe.tv/twiv.

TWiV 174: Dog runs and mooing miRs

On episode #174 of the podcast This Week in Virology, Vincent, Alan, and Rich consider whether pet dogs might transmit human noroviruses, and an RNA virus microRNA that might be involved in oncogenesis.

You can find TWiV #174 at www.microbe.tv/twiv.

TWiV 143: Live at ASV in Minneapolis

asv minneapolisHosts: Vincent Racaniello, Rich Condit, Julie Overbaugh, and Stacey Schultz-Cherry

Vincent, Rich, Julie and Stacey recorded TWiV at the 30th Annual Meeting of the American Society for Virology in Minneapolis, where they discussed the role of neutralizing antibodies in protection against HIV-1 infection, and astroviruses, agents of gastroenteritis.

Click the arrow above to play, or right-click to download TWiV 143 (48 MB .mp3, 66 minutes).

Subscribe to TWiV (free) in iTunes , at the Zune Marketplace, by the RSS feed, by email, or listen on your mobile device with the Microbeworld app.

Links for this episode:

Weekly Science Picks

Rich – Iter – building a fusion reactor
Vincent – American girls sweep at Google science fair (NY Times)

Listener Pick of the Week

JingBees by Rudolph Steiner

Send your virology questions and comments (email or mp3 file) to twiv@microbe.tv, or call them in to 908-312-0760. You can also post articles that you would like us to discuss at microbeworld.org and tag them with twiv.

Happy as a clam? Maybe not.

oystersThis article was written for extra credit by a student in my recently concluded virology course.

by Adriana Lopez

The expression “Happy as a Clam” comes with new meaning as hepatitis A virus has been detected in clams, mussels, and oysters in markets for human consumption. As bivalve shellfish are excellent bio-accumulators of contaminants and chemicals, it is no surprise that they also harbor waterborne viruses such as hepatitis A in areas with poor sanitation. Since hepatitis A virus is spread via the fecal-oral route, food-borne outbreaks due to ingestion of shellfish harvested from polluted waters have not been uncommon.

Despite development of an effective vaccine against hepatitis A virus, it continues to be a serious disease worldwide. In developing countries, access to healthcare and vaccination may not be available and many remain susceptible to infection. Eating raw or undercooked shellfish may pose a serious food safety threat to those unvaccinated in the event the mollusks are infected. Though many people have inapparent infections at a young age and acquire immune memory to hepatitis A, infections in adults can be quite severe and have led to death in some instances. While hepatitis A vaccination has been routinely administered to children in developed countries, anti-vaccine sentiments and public complacency have led to decreased childhood vaccination of hepatitis A. Though herd immunity* will likely protect susceptible individuals in developed nations at present, potential for outbreaks in the future is greatly increased if people continue to refuse vaccination and shellfish suspect to contamination are imported/shipped to market. As such, the U.S. Department of Agriculture (USDA) is considering different approaches to ensure the safety of human health in shellfish consumption.

One of the most promising techniques being studied by the USDA in regard to hepatitis A contaminated shellfish is known as high pressure processing (HPP). This commercial technology is already used for processing of several products in the food industry and demonstrates potential for inactivation of hepatitis A virus in shellfish. In laboratory tests, HPP treatment of 60,000 pounds per square inch of pressure for five minutes exhibited inactivation of 99.9% of hepatitis A in oysters subjected to the pathogen. Since human hepatitis A virus strains are unable to replicate in the tissues of contaminated shellfish, virions damaged or inactivated by HPP processing are unable to replicate and repair themselves to restore infectivity. However, since shellfish osmoregulate – meaning the osmotic pressure of the organism’s body fluids are kept the same as the surrounding water – different pressures may need to be applied to inactivate virus for shellfish found at various depths as mutants may have been selected for pressure sensitivity. While there are some concerns for how this technique may affect the texture and taste of the shellfish, HPP is a promising technique for treatment of shellfish potentially infected with hepatitis A virus.

*herd immunity: the concept that if you immunize ‘enough people,’ (a complicated variable that differs according to the virus, social issues/beliefs, population, and environment) virus spread stops when the probability of infection drops below a critical threshold. Not everyone needs to be immunized to protect the population.

 Kingsley, D. (2004). Inactivation of selected picornaviruses by high hydrostatic pressure Virus Research, 102 (2), 221-224 DOI: 10.1016/j.virusres.2004.01.030
 Terio, V., Tantillo, G., Martella, V., Pinto, P., Buonavoglia, C., & Kingsley, D. (2010). High Pressure Inactivation of HAV Within Mussels Food and Environmental Virology, 2 (2), 83-88 DOI: 10.1007/s12560-010-9032-7
 Kingsley, D., Calci, K., Holliman, S., Dancho, B., & Flick, G. (2009). High Pressure Inactivation of HAV Within Oysters: Comparison of Shucked Oysters with Whole-In-Shell Meats Food and Environmental Virology, 1 (3-4), 137-140 DOI: 10.1007/s12560-009-9018-5

TWiM 8: Live in NOLA

This Week in Microbiology #8Hosts: Vincent Racaniello, Michael Schmidt, Stan Maloy, Andreas Baümler, Nicole Dubilier, and Paul Rainey.

Vincent, Michael, and Stanley recorded episode #8 of the podcast This Week in Microbiology live at the 2011 ASM General Meeting in New Orleans, with guests Andreas Baümler, Nicole Dubilier, and Paul Rainey. They spoke about how pathogens benefit from disease, symbioses between chemosynthetic bacteria and marine invertebrates, and repetitive sequences in bacteria.

Click the arrow above to play, or right click to download TWiM #8 (60 MB, .mp3, 87 minutes).

Subscribe to TWiM (free) on iTunesZune Marketplace, via RSS feed, by email or listen on your mobile device with the Microbeworld app.

Links for this episode:

 

Send your microbiology questions and comments (email or mp3 file) to twim@microbe.tv, or call them in to 908-312-0760. You can also post articles that you would like us to discuss at microbeworld.org and tag them with twim.

TWiV 134: Meet Ralph, your cruise director

norovirusHosts: Vincent Racaniello, Rich Condit, Dickson DespommierAlan Dove, and Stephanie Karst

Vincent, Rich, Alan, and Dickson review noroviruses with Stephanie Karst, PhD.

Click the arrow above to play, or right-click to download TWiV #134 (68 MB .mp3, 94 minutes).

Subscribe to TWiV (free) in iTunes , at the Zune Marketplace, by the RSS feed, by email, or listen on your mobile device with the Microbeworld app.

Links for this episode:

Weekly Science Picks

Stephanie – Effectors of the type I interferon response (Nature)
Dickson – Receptor for Ebola virus (PNAS)
Rich
A History of Vaccines
Alan – The Worst Journey in the World by Apsley Cherry-Garrard
Vincent – ASM Live 2011 webcast

Listener Pick of the Week

Sophie  – TED talk app for iPad and iPhone

Send your virology questions and comments (email or mp3 file) to twiv@microbe.tv, or call them in to 908-312-0760. You can also post articles that you would like us to discuss at microbeworld.org and tag them with twiv.

TWiM 4: Cantaloupes and Salmonella gastroenteritis

cantaloupe recallHosts: Vincent Racaniello, Margaret McFall-Ngai, Cliff Mintz, and Michael Schmidt.

On episode #4 of the podcast This Week in Microbiology, Vincent, Cliff, Margaret, and Michael review foodborne bacterial illness in the context of outbreaks associated with cantaloupes and Lebanon bologna.

Click the arrow above to play, or right click to download TWiM #4 (51 MB .mp3, 75 minutes).

Subscribe to TWiM (free) on iTunesZune Marketplace, via RSS feed, by email or listen on your mobile device with the Microbeworld app.

Links for this episode:

Send your microbiology questions and comments (email or mp3 file) to twim@microbe.tv, or call them in to 908-312-0760. You can also post articles that you would like us to discuss at microbeworld.org and tag them with twim.