October 21, 2013

Illinois River Otters Exposed to Chemicals Banned Decades Ago and other wildlife disease news stories


Avian Influenza Virus Detection Using Smell

New research from the Monell Chemical Senses Center and the U.S. Department of Agriculture (USDA) reveals how diseases can modify animal odors in subtle ways. In a recent study published in the public access journal PLOS ONE, scientists examined how infection with avian influenza (AIV) alters fecal odors in mallards.

Using both behavioral and chemical methods, the findings reveal that AIV can be detected based on odor changes in infected birds.

"The fact that a distinctive fecal odor is emitted from infected ducks suggests that avian influenza infection in mallards may be 'advertised' to other members of the population," notes Bruce Kimball, PhD, a research chemist with the USDA National Wildlife Research Center (NWRC) stationed at the Monell Center. "Whether this chemical communication benefits non-infected birds by warning them to stay away from sick ducks or if it benefits the pathogen by increasing the attractiveness of the infected individual to other birds, is unknown."

In the study, laboratory mice were trained to discriminate between feces from AIV-infected and non-infected ducks, indicating a change in odor. Chemical analysis then identified the chemical compounds associated with the odor changes as acetoin and 1-octen-3-ol.

Science Daily
16 Oct 2013

Cited Journal Article
Bruce A. Kimball, Kunio Yamazaki, Dennis Kohler, Richard A. Bowen, Jack P. Muth, Maryanne Opiekun, Gary K. Beauchamp. Avian Influenza Infection Alters Fecal Odor in Mallards. PLoS ONE, 2013; 8 (10): e75411 DOI: 10.1371/journal.pone.0075411

Deadly fungus cripples frog immune systems

The killer fungus ravaging amphibian populations around the world is so deadly because it secretes a chemical that causes its hosts' white blood cells to self-destruct. Once the molecule responsible for this attack is identified, it may be possible to combat the disease by bolstering species' immune systems.

... But this vulnerability is surprising. After all, amphibians spend a lot of their lives in pools of murky water, teeming with all kinds of microorganisms. "Amphibians have really capable immune systems, yet here they are stumbling against this skin pathogen," says Louise Rollins-Smith, an immunologist at Vanderbilt University in Nashville, Tennessee. "Why does this pathogen seem to fail to activate that robust response?"

To find out, Rollins-Smith and her colleagues tested the effect of chytrid fungal cells on white blood cells, or lymphocytes, cultured from frogs. They found that both live and heat-killed chytrids inhibited the production of lymphocytes and made them more likely to self-destruct in a process called apoptosis – the way old or damaged cells are naturally cleared from the body. The loss of these cells leaves the animals unable to eradicate the chytrid infection before it does further damage to their skin cells.

New Scientist
18 Oct 2013
B Holmes

Illinois River Otters Exposed to Chemicals Banned Decades Ago

Researchers report that river otters in Central Illinois are being exposed to polychlorinated biphenyls (PCBs) and pesticides that were banned in the U.S. in the 1970s and '80s. Their analysis appears in the journal Ecotoxicology and Environmental Safety.

The Illinois Department of Natural Resources collected 23 river otters between 2009 and 2011, after the animals were incidentally killed (hit by cars or accidentally caught in traps, for example). The agency passed the carcasses along to researchers at the Illinois Natural History Survey for analysis, and the University of Illinois Veterinary Diagnostic Laboratory conducted autopsies.

As part of this effort, the research team, led by wildlife technical assistant Samantha Carpenter and wildlife veterinary epidemiologist Nohra Mateus-Pinilla, both with the natural history survey, and U. of I. animal sciences professor Jan Novakofski, looked at liver concentrations of 20 organohalogenated compounds once used in agriculture and industry (all but one of which were later banned). Andreas Lehner, of Michigan State University, conducted the toxicological tests.

Science Daily
15 Oct 2013

Cited Journal Article
Samantha K Carpenter, Nohra E. Mateus-Pinilla, Kuldeep Singh, Andreas Lehner, Damian Satterthwaite-Phillips, Robert D. Bluett, Nelda A. Rivera, Jan E. Novakofski. River otters as biomonitors for organochlorine pesticides, PCBs, and PBDEs in Illinois. Ecotoxicology and Environmental Safety, 2013; DOI: 10.1016/j.ecoenv.2013.07.028

Killer virus no longer killing Great Lakes fish

A virus that caused large fish kills in the Great Lakes since 2005 may now be harmless.

Viral hemorrhagic septicemia or VHS has been found in several spots in Lake Michigan and Lake Superior since 2009 and is blamed for large-scale fish die-offs in all of the lower Great Lakes. But now, it appears this virus is benign. VHS can cause the internal organs of fish to rupture, and it was feared that it would wipe out commercial fishing. But Wisconsin Department of Natural Resources Lake Superior Fisheries Supervisor Peter Stevens in Bayfield says even though the virus is still in the lake, they haven’t found any fish kills this year — not one — from VHS.

“It does not seem to be causing massive fish kills or significant impacts to the fisheries resource, so far as we can tell,” he said. “There are a number of theories. We really don’t have an exact answer.”

Stevens says it appears fish have created their own VHS vaccine. “Those fish species will shed a little bit of the virus every year which acts almost like a booster shot to the fish immune system, causing these antibodies to be produced.”

Ironically, money to continue surveying fish for VHS was cut by the federal government this year, so they’re dependent on commercial and recreational anglers. But this year, there have been no reports of fish killed from VHS.

Wisconsin Public Radio
18 Oct 2013
M Simonson

Global Health News Corner
Prion Disease News
Epizootic Hemorrhagic Disease
Huh!? That's Interesting!

No comments: