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:4/5/2017)... -- The Allen Institute for Cell Science today announces the ... and dynamic digital window into the human cell. The ... of deep learning to create predictive models of cell ... growing suite of powerful tools. The Allen Cell Explorer ... available resources created and shared by the Allen Institute ...
(Date:4/5/2017)... -- KEY FINDINGS The global market for ... of 25.76% during the forecast period of 2017-2025. The ... the growth of the stem cell market. ... INSIGHTS The global stem cell market is segmented on ... stem cell market of the product is segmented into ...
(Date:4/3/2017)... 3, 2017  Data captured by IsoCode, ... detected a statistically significant association between the ... treatment and objective response of cancer patients ... predict whether cancer patients will respond to ... well as to improve both pre-infusion potency testing ...
Breaking Biology News(10 mins):
(Date:10/9/2017)... (PRWEB) , ... October 09, 2017 , ... ... a four-tiered line of medical marijuana products targeting the needs of consumers who ... packaging of Kindred takes place in Phoenix, Arizona. , As operators of two ...
(Date:10/7/2017)... (PRWEB) , ... October 06, ... ... years’ experience providing advanced instruments and applications consulting for microscopy and surface ... expertise in application consulting, Nanoscience Analytical offers a broad range of contract ...
(Date:10/7/2017)... WALTHAM, Mass. , Oct. 6, 2017 /PRNewswire/ ... pioneering work of three scientists, Jacques Dubochet, ... whose breakthrough developments in cryo-electron microscopy ... this technology within the structural biology community. The ... Scientific. Scientists can now routinely produce highly resolved, ...
(Date:10/6/2017)... D.C. (PRWEB) , ... October 06, 2017 , ... ... will host a lunch discussion and webinar on INSIGhT, the first-ever adaptive clinical ... Principal Investigator, Dana-Farber Cancer Institute. The event is free and open to the ...
Breaking Biology Technology:
Cached News: