Researchers have identified five enzymes that are essential to the survival of a parasitic worm that infects livestock worldwide and is a great threat to global food security. Two of these proteins are already being studied as potential drug targets against other pathogens.
The team sequenced the genome of Haemonchus contortus, or the barber pole worm, a well-studied parasitic worm that resides in the gut of sheep and other livestock globally. This genome could provide a comprehensive understanding of how treatments against parasitic worms work and point to further new treatments and vaccines. Their work was published in Genome Biology.
Univ. of British Columbia researchers have apprehended tiny, elusive parasites that have plagued oysters from British Columbia to California. First reported in 1960, Denman Island disease is caused by Mikrocytos mackini, a parasite that infects mainly Pacific oysters, and leads to unsightly green lesions and death.
“M. mackini has eluded capture for more than 50 years because it lives inside the oyster’s cells and has proved impossible to grow and study in a lab,” says Patrick Keeling a professor in UBC’s Department of Botany who led the microbial investigative team.
Simple Math May Solve Mystery of Parasite Energetics
Feeling faint from the flu? Is your cold causing you to collapse? Your infection is the most likely cause, and, according to a new study by UC Santa Barbara research scientist Ryan Hechinger, it may be possible to know just how much energy your bugs are taking from you. His findings are published in a recent issue of The American Naturalist.
"When we get sick –– particularly with infectious agents –– we often talk about having our ‘energy drained,’ or of ‘having low energy,’" says Hechinger, an associate research biologist at UCSB’s Marine Science Institute and Department of Ecology, Evolution and Marine Biology. "This common language highlights that energy may provide a useful currency to investigate how infectious agents, or parasites, impact their hosts."
Parasites are ubiquitous. They feed on virtually every animal and even on each other. Yet, for all the parasites’ collective contributions to biomass and biodiversity, conventional food webs don’t account for the presence of these tiny and numerous consumers. A recent study featuring work by several UC Santa Barbara scientists focuses on the impact parasites have on food webs, with findings that are expected to alter our picture of who-eats-who. A paper on the work appears in the latest edition of PLoS Biology.
"If you are not including parasites in food webs, you aren’t getting the whole picture," says Kevin Lafferty, a marine ecologist with the U.S. Geological Survey, and adjunct professor in the UCSB Department of Ecology, Evolution and Marine Biology (EEMB). "They are consumers like predators, but they are less visible and easy to forget."
Fish with parasites attached to their heads have a stronger preference for left or right when facing a T-intersection, giving them an edge when it comes to escaping predators, research from The Australian National Univ. (ANU) has revealed.
A preference for one side is called lateralization. Many human behaviors, such as being left-or right-handed when writing, are lateralized due to the body’s asymmetries and different wiring in the brain’s hemispheres.
Melbourne scientists have made the surprise discovery that malaria parasites can “talk” to each other – a social behavior to ensure the parasite’s survival and improve its chances of being transmitted to other humans.
The finding could provide a niche for developing anti-malarial drugs and vaccines that prevent or treat the disease by cutting these communication networks.
Infection Renders Mosquitoes Immune to Malaria Parasites
Scientists funded by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, have established an inheritable bacterial infection in malaria-transmitting Anopheles mosquitoes that renders them immune to malaria parasites. Specifically, the scientists infected the mosquitoes with Wolbachia, a bacterium common among insects that previously has been shown to prevent malaria-inducing Plasmodium parasites from developing in Anopheles mosquitoes. Before now, researchers had been unable to create mosquitoes with a stable Wolbachia infection that passed consistently from mother to offspring.
On the list of undesirable medical conditions, a parasitic worm infection surely ranks fairly high. Although modern pharmaceuticals have made them less of a threat in some areas, these organisms are still a major cause of disease and disability throughout much of the developing world.
But parasites are not all bad, according to new research by a team of scientists now at the Univ. of Georgia, the Harvard School of Public Health, the Université François Rabelais in Tours, France, and the Central South Univ., Changsha, Hunan, China. A study published recently in Nature Medicine demonstrates that once inside a host, many parasitic worms secrete a sugar-based anti-inflammatory molecule that might actually help treat metabolic disorders associated with obesity.
A parasite thought to be harmless and found in many people may actually be causing subtle changes in the brain, leading to suicide attempts. New research appearing in the Journal of Clinical Psychiatry adds to the growing work linking an infection caused by the Toxoplasma gondii parasite to suicide attempts. Michigan State Univ.’s Lena Brundin was one of the lead researchers on the team.
About 10-20 percent of people in the United States have Toxoplasma gondii, or T. gondii, in their bodies, but in most it was thought to lie dormant, says Brundin, an associate professor of experimental psychiatry in MSU’s College of Human Medicine. In fact, it appears the parasite can cause inflammation over time, which produces harmful metabolites that can damage brain cells.
A long forgotten foe is beginning to reemerge on pastures and meadows around the world, and farmers are finding that they have no way to combat it. Parasitic worms infecting cows, sheep, goats and horses are becoming resistant to the drugs used to kill them. If changes are not made in how the few remaining drugs that still work are used, there may be no way left to fight the growing threat, according to Ray Kaplan, a Univ. of Georgia professor in the department of infectious diseases.
Kaplan has studied drug-resistant parasites for years and his findings, recently published in the journal Veterinary Parasitology, warn that the continued overuse of deworming drugs has the potential to create parasites that cannot be killed.
Researchers at the Univ. of Sheffield have discovered a parasitic mite has caused the Deformed Wing Virus to proliferate in honey bee colonies. This association is now thought to contribute to the worldwide spread and probable death of millions of honey bee colonies. The current monetary value of honey bees as commercial pollinators in the United States alone is estimated at about $15-$20 billion annually.
The research conducted in Hawaii by researchers from the Univ. of Sheffield, the Marine Biological Association, the Food and Environment Research Agency and the Univ. of Hawaii, and reported in the journal Science, showed how the Varroa mite caused Deformed Wing Virus (DWV) – a known viral pathogen – to increase its frequency among honey bee colonies from 10 percent to 100 percent.
Research by a collaborative group of scientists from UC San Diego School of Medicine, UC San Francisco and Wake Forest School of Medicine has led to identification of an existing drug that is effective against Entamoeba histolytica. The parasite causes amebic dysentery and liver abscesses and results in the death of more than 70,000 people worldwide each year.
Using a high-throughput screen for drugs developed by the research team, they discovered that auranofin — a drug approved by the US Food and Drug Administration 25 years ago for rheumatoid arthritis — is very effective in targeting an enzyme that protects amebae from oxygen attack (thus enhancing sensitivity of the amebae to reactive oxygen-mediated killing).
A chemically altered osteoporosis drug may be useful in fighting malaria, researchers report in a new study. Unlike similar compounds tested against many other parasitic protozoa, the drug readily crosses into the red blood cells of malaria-infected mice and kills the malaria parasite. The drug works at very low concentrations with no observed toxicity to the mouse. The study appears in the Proceedings of the National Academy of Sciences.
Fruit flies infected with a blood-borne parasite consume alcohol to self-medicate, a behavior that greatly increases their survival rate. “We believe our results are the first to show that alcohol consumption can have a protective effect against infectious disease, and in particular against blood-borne parasites,” says Todd Schlenke, an evolutionary geneticist at Emory Univ. who led the research.
New research from the Univ. of Melbourne shows how the malaria parasite (Plasmodium falciparum) changes into a banana shape before sexual reproduction, a finding that could provide targets for vaccine or drug development and may explain how the parasite evades the human immune system. The work was conducted by an Australian research team led by Matthew Dixon and PhD student Megan Dearnley from the Department of Biochemistry and Molecular Biology, Bio21 Institute at the Univ. of Melbourne, and is published in the Journal of Cell Science.