HOME >> BIOLOGY >> NEWS
The results are in: Bacterial parasite strives for balance in host infection

When horror-movie writers run out of ideas, they can always turn to parasites. Imagine the possibilities with flesh-eating bacteria, suicide-inducing hairworms, scalp burrowing botflies--and castrating parasites. Such debilitating effects are an inevitable consequence of infection, but it is in the parasite's interest to avoid killing the host until it can transmit a new crop of pathogens. In the "tradeoff hypothesis" for the evolution of virulence--how quickly a parasite kills its host--host exploitation and parasite reproduction are balanced to maximize the parasite's lifetime transmission success. But lifetime transmission success, an indicator of parasite fitness, has proven difficult to measure, leaving scant direct evidence for an optimal level of virulence. In a new study, Knut Helge Jensen, Dieter Ebert, and colleagues now provide empirical evidence that such a trade-off exists.

The authors worked with water fleas (Daphnia magna) and the castrating bacterium Pasteuria ramosa to investigate the relationship between parasite fitness and virulence. Castrating parasites divert resources from host reproduction toward their own reproductive ends. In the case of P. ramosa, that means generating transmission-stage parasites, or spores. In keeping with the tradeoff hypothesis, the researchers predicted that the parasite should castrate early to optimize the appropriation of host resources, and produce intermediate levels of virulence to keep the host alive long enough to maximize spore production. To determine the relationship between virulence and lifetime production of transmission-stage parasites, the researchers exposed a Daphnia clone to bacterial spores and tracked individual host mortality. Infected Daphnia sustained far more casualties than either unexposed controls or exposed but uninfected individuals, with deaths beginning at 23 days old and ending at 74 days old. (The first control died at 96 days old.) Early host death (high virulence) wa
'"/>

Contact: Natalie Bouaravong
press@plos.org
415-568-3445
Public Library of Science
29-May-2006


Page: 1 2

Related biology news :

1. Cooperative science program yields results
2. Delayed treatment of childhood-onset bipolar disorder results in negative outcome in adults
3. Smelling for first time results from knowing abnormalities in congenital loss of smell
4. BDSI announces positive phase III clinical trial results
5. Scientists meet to review Envisat results after 5 years of operations
6. Environment and exercise may affect research results, UA study shows
7. Preliminary results of largest scan of autism DNA information
8. Human trial results show excellent safety data, from Geovaxs DNA/MVA AIDS vaccines
9. Rodent sperm work together for better results
10. Dramatic results from combo therapy surprises Krabb-disease researchers
11. TIGER workshop highlights project results

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/18/2017)... SUNNYVALE, Calif. , April 18, 2017  Socionext Inc., a ... prototype of a media edge server, the M820, which features the ... face recognition software provided by Tera Probe, Inc., will be showcased ... and at the NAB show at the Las Vegas ... ...
(Date:4/13/2017)... , April 13, 2017 UBM,s Advanced ... will feature emerging and evolving technology through ... Innovation Summits will run alongside the expo portion of ... sessions, panels and demonstrations focused on trending topics within ... advanced design and manufacturing event will take place June ...
(Date:4/11/2017)... , April 11, 2017 Crossmatch®, a ... authentication solutions, today announced that it has been ... Research Projects Activity (IARPA) to develop next-generation Presentation ... "Innovation has been a driving force ... program will allow us to innovate and develop ...
Breaking Biology News(10 mins):
(Date:10/9/2017)... SAN DIEGO , Oct. 9, 2017 /PRNewswire/ ... a biological mechanism by which its ProCell stem ... of critical limb ischemia.  The Company, demonstrated that ... the amount of limbs saved as compared to ... of the molecule HGF resulted in reduction of ...
(Date:10/9/2017)... ... 2017 , ... At its national board meeting in North Carolina, ARCS® ... Departments of Physics and Astronomy, has been selected for membership in ARCS Alumni ... the 2015 Breakthrough Prize in Fundamental physics for the discovery of the accelerating expansion ...
(Date:10/9/2017)... ... October 09, 2017 , ... ... 2017, in the medical journal, Epilepsia, Brain Sentinel’s SPEAC® System which uses ... EEG, in detecting generalized tonic-clonic seizures (GTCS) using surface electromyography (sEMG). The ...
(Date:10/7/2017)... ... October 06, 2017 , ... Phase ... metagenome deconvolution product, featuring the first commercially available Hi-C kit. Researchers can ... Hi-C metagenome deconvolution using their own facilities, supplementing the company’s full-service ProxiMeta ...
Breaking Biology Technology:
Cached News: