Cholera pathogen Vibrio cholerae can grow in freshwater: epidemiological and immunological consequences
The majority of bacterial species under the Vibrio genus are common flora in brackish waters and estuaries. The causative agent of dysenteric disease cholera, Vibrio cholerae, wasn’t thought to be any different. The disease has always been associated with ingestion of contaminated water and sea food. However, researchers at the Swiss Federal Institute for Aquatic Science and Technology (EAWAG) showed that V. cholerae not only grows but actually thrives in freshwater.
The study focused on the V. cholerae O1 Ogawa El Tor strain, one of the serotypes responsible for the recently reported outbreaks in India. Study results show that the bacterium is actually euryhaline and can grow in a wide range of salinities ranging from brackish to lake waters. A determinant factor for its growth in freshwater is the amount of apparent assimilable organic carbon (AOCapp). V. cholerae produces a toxin that causes the characteristic diarrheal symptoms of the disease.
In another European study, Belgian researchers looked more in detail into the transport mechanisms of the B-protomer subunit of the cholera toxin. According to Vanden Broeck and colleagues (2007), the B-subunit “displays the capacity to fortify immune responses to certain antigens, to act as a carrier and to be competent in inducing immunological tolerance.”These findings have some consequences on the epidemiology and preventive strategies of cholera.
The first study highlights the risks of contamination not only in coastal waters but in inland areas and lakes while the second study indicates a potential use for the cholera toxin in vaccine development.
Air Pollution and CVD Risks: The Beijing Olympics Challenge
As the 2008 Olympic games approach, more and more countries are getting concerned about the consequences of Beijing’s air quality on the health of their athletes. And rightly so. Results of recent studies indicate that the magnitude of the effects of fine particulate pollution on the general population may be actually larger than previously thought.
In the February issue of NEJM (vol. 356. pp. 447-458), Miller et al. presented the results of a large, prospective cohort study (N=65,893) in postmenopausal American women exposed to particles with diameters smaller than 2.5 µm (PM2.5). The median follow-up period was 6 years. They report that with each increase of 10 µg PM2.5 per cubic meter of air, there is a 24% increase in the risk of a cardiovascular event and a 76% increase in the risk of death from cardiovascular disease. What is also alarming is that these risks increase with increasing BMI.
A more recent report from a German prospective study by Hoffman et al. (Circulation, vol. 116:489-496) linked traffic-generated fine particles to coronary artery calcification – within just a period of 5 years. Although this study is relatively smaller (N=4494), study subjects included both sexes with a wider age range of 45 to 74 years.
The US Environmental Protection Agency set health standards on air pollution way back in 1997 but only managed to finalize its Clean Air Fine Particle Implementation Rules this year. China and Beijing promise to achieve more than that in less than a year. Can they deliver?
Photo credit: http://www.terradaily.com/news/pollution-05zr.html
Biotechnology and Health Meetings: Spain is the place to go this autumn
Spain is the venue of two major European conferences in autumn. The first one is the 13th European Congress on Biotechnology to be held in Barcelona on 16 to 19 September. This will be followed by the European Conference on Synthetic Biology (ECSB) in Costa Brava on 24 to 29 November.
The Biotech Conference’s main theme this year is Symbiosis (Science, Industry and Society). In additi
on, other themes on Health & Medicine, Functional Genomics & Systems Biology, & Green Biotechnology will also be addressed. The conference always draws big names in the field of biotechnology. Among this year’s plenary speakers are Prof. Svante Päävo, head of the Department of Evolutionary Genetics of the prestigious Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and Prof. Donald Hilvert, director of the Hilvert Lab of the Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland. Under Health & Medicine, sessions on targeted medicines, nanobiotechnology, and gene delivery systems will especially be relevant for medical researchers.
The scope of ECSB is narrower since it deals with the relatively new, cutting-edge field of synthetic biology. This year’s theme is on Design, Programming and Optimisation of Biological Systems. However, the potential application of synthetic biology in our society is enormous “with its effects being felt across a range of activities such as the provision of healthcare, environmental protection and remediation to the construction of smarter more ubiquitous bio-integrated computing systems…” Topics on genomics, natural and directed evolution, and cell cycles & circuits promise to be especially interesting.
Both conferences are supported by the European Science Foundation, the European Federation of Biotechnology and several industry sponsors consisting of global movers in the field of biotechnology and pharmaceuticals.
Photo credit: http://www.esf.org/conferences/07241