Journalsynthesis Domino

7/29/2019 Journalsynthesis Domino

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SYNTHESIS

JOURNAL 1: Anwar Huq. Simple Sari Filtration is Sustainable andContinues to Protect Villagers from Cholera in Matlab, Bangladesh.

mBio, 2010; DOI: 10.1128/mBio.00034-10

Sari Cloth a Simple Sustainable Protector from Cholera

A five-year follow up study in Bangladesh finds that women are literallywearing the answer to better health for themselves, their families and eventheir neighbors. Using the simple sari to filter household water protects notonly the household from cholera, but reduces the incidence of disease inneighboring households that do not filter.

"A simple method for filtering pond and river water to reduce the incidence ofcholera, field tested in Matlab, Bangladesh, proved effective in reducing theincidence of cholera by 48 percent. This follow-up study conducted 5 yearslater showed that 31 percent of the village women continued to filter water fortheir households, with both an expected and an unexpected benefit," saysRita Colwell of the University of Maryland, College Park, a researcher on thestudy.

In 2003, Colwell and her colleagues reported the results of a field study thatdemonstrated by simply teaching village women responsible for collectingwater to filter the water through folded cotton sari cloth, they could reduce the

incidence of cholera in that group by nearly half. Though the results werepromising at the time of the research, there was concern that the practice ofsari water filtration would not be sustained in later years.

Five years later they conducted the follow-up study to determine whether sariwater filtration continued to be practiced by the same population ofparticipants and, if it were, whether there would continue to be a beneficialeffect of reduced incidence of cholera.

Over 7,000 village women collecting water daily for their households inBangladesh were selected from the same population used in the previous

study. Survey data showed that 31 percent continued to filter their water, ofwhich 60 percent used a sari. Additionally, they found that of the control group(the one that did not receive any education or training in the first study) 26percent of households now filter their water.

"This is a clear indication of both compliance with instructions and thesustainability of the method, but it also shows the need for continuingeducation in the appropriate use and benefits of simple filtration," saysColwell.

The researchers also looked at the incidence of cholera in households during

the 5-year follow-up period. While not statistically significant, they found theincidence of hospitalizations for cholera during that period reduced by 25


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percent.

"With the lower rate of filtration in this follow-up study, it is not surprising thatthe observed reduction in disease rate was not as high as the 48 percentobserved in the original trial, suggesting that active reinforcement would have

been effective in ensuring higher protection," says Colwell.

They also found an indirect benefit. Households that did not filter their waterbut were located in neighborhoods where water filtration was regularlypracticed by others also had a lower incidence of cholera.

"Results of the study showed that the practice of filtration not only wasaccepted and sustained by the villagers but also benefited those who filteredtheir water, as well as neighbors not filtering water for household use, inreducing the incidence of cholera," says Colwell.

JOURNAL 2:Lowden et al. Structure of Vibrio cholerae ToxT reveals amechanism for fatty acid regulation of virulence genes. Proceedings ofthe National Academy of Sciences, 2010; DOI: 10.1073/pnas.0915021107

How Cholera Bacteria Becomes Infectious

In a study, Dartmouth researchers describe the structure of a protein calledToxT that controls the virulent nature ofVibrio cholerae, the bacteria thatcauses cholera. Buried within ToxT, the researchers were surprised to find afatty acid that appears to inhibit ToxT, which prevents the bacteria fromcausing cholera. Cholera, which causes acute diarrhea, can be lifethreatening, and, according to the World Health Organization, cholera remainsa serious threat to global health.

Doctors have known that bile, found in the intestine, inhibits the expression ofthe virulence genes in V. cholerae, but until now, the mechanism behind thiswas not completely understood. This study provides a direct link between theenvironment of the gut and the regulation of virulence genes, and it alsoidentifies the regulatory molecule.

"Finding a fatty acid in the structure was quite a surprise," says F. Jon Kull,

associate professor of chemistry at Dartmouth and senior author on thepaper. Kull is also a 1988 graduate of Dartmouth. "The exciting thing aboutthis finding is that we might be able to use a small, natural molecule to treatand/or prevent cholera. We will also use the structure of the fatty acid as aframework to try and design a small molecule inhibitor of ToxT."

Kull's co-authors on the paper are Michael Lowden and Maria Pellegrini withthe Department of Chemistry at Dartmouth; Michael Chiorazzo, a summerundergraduate research fellow; and Karen Skorupski and Ronald Taylor withthe Department of Microbiology and Immunology at Dartmouth MedicalSchool.

The researchers used X-ray crystallography to determine the structure of


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ToxT. The process involves taking DNA from V. cholerae and using non-pathogenic E. coli bacteria to produce large amounts of the target protein, inthis case, ToxT. Once protein has been purified, it is concentrated andcrystallized. Then the crystal, which is an ordered array of protein molecules,is subjected to a powerful X-ray beam. The pattern of diffracted X-rays is

collected on a detector and then analyzed using mathematical algorithms,eventually revealing the atomic structure of the protein.

Co-author Taylor also notes that "The results of the study are exciting fromthe points of view of both the mechanistic aspect of the complex regulation ofV. cholerae virulence gene expression and the potential medical impact as wenow move forward to apply this new knowledge to influence this mechanismto control infection in humans."

JOURNAL 3: Society for General Microbiology (2009, September 8).

Designing Probiotics That Ambush Gut Pathogens

Researchers in Australia are developing diversionary tactics to fool disease-causing bacteria in the gut. Many bacteria, including those responsible formajor gut infections, such as cholera, produce toxins that damage humantissues when they bind to complex sugar receptors displayed on the surfaceof cells in the host's intestine.

At the Society for General Microbiology's meeting at Heriot-Watt University,Edinburgh, Professor James Paton and colleagues from the University ofAdelaide explained how they had added molecular mimics of these host cellreceptors onto the surface of harmless bacteria capable of surviving in thehuman gut. If given during an infection caused by a toxin-producingbacterium, these "receptor-mimic probiotics" will bind the toxins in the gut verystrongly, thereby preventing the toxins from interacting with receptors on hostintestinal cells and causing disease.

Effective vaccines are not yet available for many diarrhoeal diseases; andtrying to control or treat these diseases with antibiotics can lead to thedevelopment of drug-resistance. One advantage of this approach to treatmentis that the pathogenic bacteria are unlikely to develop a resistance to it, as

that would destroy the basic mechanism by which they cause disease.

A further advantage is that the receptor-mimic bacteria bind toxins morestrongly than previous technologies in which synthetic receptors weredisplayed on inert silica particles. They are also more cost effective, as thebacteria can be grown cheaply in large-scale fermenters.

"We initially developed this technology to prevent disease caused by strainsof E. coli bacteria that produce Shiga toxin. These include the infamous E. coliO157 strain, which causes outbreaks of severe bloody diarrhoea and thepotentially fatal haemolytic uraemic syndrome. Our prototype receptor mimic

probiotic provided 100% protection against otherwise fatal E. coli disease inan animal model." said Professor Paton, "We have also developed similar


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receptor mimic probiotics that are capable of preventing cholera andtravellers' diarrhoea. As well as being able to treat disease, these probioticscould be given to vulnerable populations following natural disasters to helpprevent outbreaks of diseases like cholera".

JOURNAL 3: University of Central Florida (2010, January 27).

New Vaccine Could Be Lethal Weapon Against Malaria, Cholera

A University of Central Florida biomedical researcher has developed a low-cost dual vaccine against malaria and cholera.Although it wasnt approve bythe FDA that the drug can prevent a person from malaria. There is only onevaccine for malaria and that alone is very expensive that it cannot afford byother people. The drug that they did worked well and it provided an affordableway to get vaccines to people who needed it the most and can least afford it.

In his experiment he made use of rodents to test his drug.


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REACTION

Cholera is a disease that is needed to be taken seriously. As Ivelearned in school, the cholera bacterium is usually found in water or foodsources that have been contaminated by feces (poop) from a person infectedwith cholera. Usually the victims are those people who live near a pond/riverorthose that have poor hygiene and who doesnt prepare their food well. Aswe all know the cure for this disease is not just merely having a goodsanitation but also the need for a vaccine. Ive research about someprevention from this disease and one of which is the Sari Cloth, it is used tofilter ponds etc. And the other one in which a researcher made a vaccine thatis affordable and accessible to those people who cant afford them and whomare far from civilization. It is really great to know that there are people who findways in preventing this disease. I just hope that someday a drug will be made

not just prevent people from having the disease but also kill the disease sothat people will not go through what others have gone through with thisdisease.

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