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:6/2/2016)... Perimeter Surveillance & Detection Systems, ... Infrastructure, Support & Other Service  The latest ... comprehensive analysis of the global Border Security market ... of $17.98 billion in 2016. Now: In ... in software and hardware technologies for advanced video surveillance. ...
(Date:5/12/2016)... 12, 2016 , a brand ... overview results from the Q1 wave of its quarterly ... was consumers, receptivity to a program where they would ... health insurance company. "We were surprised to ... Michael LaColla , CEO of Troubadour Research, "primarily ...
(Date:4/26/2016)... and LONDON , April ... part of EdgeVerve Systems, a product subsidiary of ... today announced a partnership to integrate the Onegini ...      (Logo: ) ... their customers enhanced security to access and transact ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... ... June 23, 2016 , ... ... and Mold) microbial test has received AOAC Research Institute approval 061601. , “This ... introduced last year,” stated Bob Salter, Vice President of Regulatory and Industrial Affairs. ...
(Date:6/23/2016)...   EpiBiome , a precision microbiome engineering company, ... financing from Silicon Valley Bank (SVB). The financing will ... its drug development efforts, as well as purchase additional ... has been an incredible strategic partner to us – ... would provide," said Dr. Aeron Tynes Hammack , ...
(Date:6/23/2016)... ... June 23, 2016 , ... In a new case report published ... how a patient who developed lymphedema after being treated for breast cancer benefitted from ... the paradigm for dealing with this debilitating, frequent side effect of cancer treatment. ...
(Date:6/23/2016)... 2016 Andrew D ... Published recently in ... from touchONCOLOGY, Andrew D Zelenetz , discusses ... care is placing an increasing burden on healthcare ... therapies. With the patents on many biologics expiring, ...
Breaking Biology Technology: