Printer Friendly

Sandfly spit boosts parasite potential.

Sandfly spit boosts parasite potential

Scientists experimenting with the salivary glands of sandflies are finding that a little spit can go a long way when it comes to enhancing parasitic infectivity. Researchers at Harvard Medical School and the Harvard School of Public Health in Boston report that the tropical sandfly, Lutzomyia longipalpis, which transmits through its bite a parasitic disease, has a component in its saliva that boosts the virulence of the parasites it injects into its mammalian victims.

The researchers injected mice with measured doses of the parasite Leishmania major with and without sandfly saliva extracts, and compared the sizes of resulting skin ulcers. They found that injections with saliva resulted in sores that were five to 10 times larger than those induced by parasitic organisms alone, and that the saliva-enhanced lesions had as much as 5,000 times more parasites within a month after innoculation.

Moreover, the effect appears to be very specific; while other insect salivas can cause inflammation and a decrease in platelet aggregation in a bitten host, the researchers report that salivary extracts from insects that transmit other parasitic diseases had no effect on lesion size or the final concentration of Leishmania organisms.

The mechanism by which sandfly saliva exacerbates leishmaniasis is unknown, the scientists say. The active ingredient is apparently quite potent, however, with as little as one-tenth of a salivary gland, or 50 nanograms of protein, sufficient to produce significant effects.
COPYRIGHT 1988 Science Service, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1988, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Publication:Science News
Date:Mar 26, 1988
Previous Article:The water's always greener....
Next Article:Malaria vaccine trials are qualified success.

Related Articles
Parasite vaccine hunt follows new roads.
A parasite with the guts of a burglar.
End of river blindness in sight?
Strike the parasite and spare the host.
Herbicide curbs human parasite's spread.
DNA may reveal a fly's favorite eatery.
Role of the domestic chicken (Gallus gallus) in the epidemiology of urban visceral Leishmaniasis in Brazil. (Perspective).
Parasite pursuit: sand fly coughs up leishmania protozoan's secrets of proliferation.
Cocirculation of 2 genotypes of Toscana virus, Southeastern France.

Terms of use | Copyright © 2016 Farlex, Inc. | Feedback | For webmasters