Navigation Links
1 species, 2 outcomes: Team seeks source of body louse pathology

CHAMPAIGN, Ill. A new study seeks to determine how one parasitic species can give rise to two drastically different outcomes in its host: The human body louse (Pediculus humanus) can transmit dangerous bacterial infections to humans, while the human head louse (also Pediculus humanus) does not.

A report of the new study appears in the journal Insect Molecular Biology.

"Body louse-transmitted diseases include trench fever, relapsing fever and epidemic typhus," said University of Illinois entomology professor Barry Pittendrigh, who led the research. In a previous study, Pittendrigh and his colleagues compared the sequences of all protein-coding genes in head and body lice and determined that the two belonged to the same species despite the fact that body lice are bigger than head lice, cling to clothing instead of hair, and can transmit disease.

Since the early 2000s, Pittendrigh has worked with John M. Clark, a professor of environmental toxicology and chemistry at the University of Massachusetts, on the molecular biology and genomics of lice. Clark was a collaborator on the 2012 study, and the two have had "a long-term goal of trying to solve this question of why body lice transmit bacterial diseases and head lice don't," Pittendrigh said.

In the new study, Clark's group infected head and body lice with Bartonella quintana, the bacterium that causes trench fever. Pittendrigh's laboratory then looked at gene expression in each to see how the insects responded to the infection.

"Our experiments suggest that the head louse immune system is fairly effective in fighting off the bacteria that cause trench fever," Pittendrigh said. "However, the body lice don't seem to have as good an immune response."

The researchers discovered that several immune genes were regulated differently in head and body lice after infection with the bacteria, and the infection progressed further in body lice over time.

"By eight days post-infection, head lice had killed or contained the invading B. quintana, whereas the bacteria were still proliferating and spreading in body lice," the researchers reported.

The team cannot yet say why head and body louse immune responses differ from one another, but Pittendrigh hypothesizes that the body louse has a reason to be more tolerant of bacterial infection.

"Head and body lice have beneficial bacteria living inside them," he said. "These bacteria make vitamins that the lice need to grow and survive. Body lice tend to grow larger than head lice. It may be that a suppressed immune system allows body lice to grow more of the bacteria that make the vitamins they need, and they grow larger."

The body louse's dampened immune response would allow other invading bacteria, such as those that cause disease in humans, to also survive in its gut, he said.

"So body lice may grow bigger, but they also are more likely to get sick with the trench fever bacteria and pass the disease to humans," Pittendrigh said.

The study team also includes researchers from Purdue University, Seoul National University, the University of California at San Francisco, the University of Massachusetts and the University of Illinois department of animal biology.


Contact: Diana Yates, Life Sci Editor, U. of I. News Bureau
University of Illinois at Urbana-Champaign

Related biology news :

1. Head and body lice appear to be the same species, genetic study finds
2. Divide the Antarctic to protect native species, propose experts
3. Sri Lankan snake study reveals new species, rich biodiversity in island country
4. Plan to delist gray wolf endangers other threatened species, researchers find
5. Trial seeks improved lung-cancer screening by combining imaging and biomarkers
6. Sandia seeks commercial partners for revolutionary SpinDx medical diagnostic tool
7. Global genome effort seeks genetic roots of disease
8. Tom Bowman seeks to engage 30 million small businesses in climate response
9. Biomass research collaboration seeks to improve biofuel efficiency, bio-products quality
10. BRAIN initiative seeks tools to understand human thought, behavior, consciousness
11. Current water resources in Europe and Africa
Post Your Comments:
Related Image:
1 species, 2 outcomes: Team seeks source of body louse pathology
(Date:11/9/2015)... , Nov. 09, 2015 ... addition of the "Global Law Enforcement ... offering. --> ) has ... Law Enforcement Biometrics Market 2015-2019" report ... and Markets ( ) has announced ...
(Date:11/2/2015)... Nov. 2, 2015  SRI International has been awarded ... preclinical development services to the National Cancer Institute (NCI) ... provide scientific expertise, modern testing and support facilities, and ... pharmacology and toxicology studies to evaluate potential cancer prevention ... The PREVENT Cancer Drug Development Program is an NCI-supported ...
(Date:10/29/2015)... Va. , Oct. 29, 2015 Daon, ... today that it has released a new version of ... customers in North America have ... IdentityX v4.0 also includes a FIDO UAF certified ... are already preparing to activate FIDO features. These customers ...
Breaking Biology News(10 mins):
(Date:11/30/2015)... 30, 2015  Northwest Biotherapeutics (NASDAQ: NWBO ) ... immune therapies for solid tumor cancers, announced today that ... director, and the Company welcomes Neil Woodford,s ... recent anonymous internet report on NW Bio.  The Company,s ... Linda Powers stated, "We agree with Mr. Woodford ...
(Date:11/27/2015)... (PRWEB) , ... November 27, 2015 , ... ... Program that includes over 2,000 technical presentations offered in symposia, oral sessions, ... and applied spectroscopy, covers a wide range of applications such as, but not ...
(Date:11/25/2015)... , Nov. 25, 2015  PharmAthene, Inc. (NYSE MKT: ... adopted a stockholder rights plan (Rights Plan) in an ... loss carryforwards (NOLs) under Section 382 of the Internal ... --> PharmAthene,s use of its NOLs could be ... as defined in Section 382 of the Code. In ...
(Date:11/25/2015)... QUEBEC CITY , Nov. 25, 2015 /PRNewswire/ ... "Company"), affirms that its business and prospects remain ... , Zoptrex™ (zoptarelin doxorubicin) recently received DSMB ... program to completion following review of the final ... met Phase 2 Primary Endpoint in men with ...
Breaking Biology Technology: