Researchers in Australia are developing diversionary tactics to fool disease-causing bacteria in the gut. Many bacteria, including those responsible for major gut infections, such as cholera, produce toxins that damage human tissues when they bind to complex sugar receptors displayed on the surface of cells in the host’s intestine.

At the Society for General Microbiology’s meeting at Heriot-Watt University, Edinburgh, today (8 September), Professor James Paton and colleagues from the University of Adelaide explained how they had added molecular mimics of these host cell receptors onto the surface of harmless bacteria capable of surviving in the human gut. If given during an infection caused by a toxin-producing bacterium, these “receptor-mimic probiotics” will bind the toxins in the gut very strongly, thereby preventing the toxins from interacting with receptors on host intestinal cells and causing disease.

Effective vaccines are not yet available for many diarrhoeal diseases; and trying to control or treat these diseases with antibiotics can lead to the development of drug-resistance. One advantage of this approach to treatment is 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 more strongly than previous technologies in which synthetic receptors were displayed on inert silica particles. They are also more cost effective, as the bacteria can be grown cheaply in large-scale fermenters.

“We initially developed this technology to prevent disease caused by strains of E. coli bacteria that produce Shiga toxin. These include the infamous E. coli O157 strain, which causes outbreaks of severe bloody diarrhoea and the potentially fatal haemolytic uraemic syndrome. Our prototype receptor mimic probiotic provided 100% protection against otherwise fatal E. coli disease in an animal model.” said Professor Paton, “We have also developed similar receptor mimic probiotics that are capable of preventing cholera and travellers’ diarrhoea. As well as being able to treat disease, these probiotics could be given to vulnerable populations following natural disasters to help prevent outbreaks of diseases like cholera”.

Source:
Dianne Stilwell

Society for General Microbiology Continue reading →

Mozambique’s National Council for the Fight Against AIDS (CNCS) on Tuesday launched a project that aims to improve the media’s coverage of the country’s HIV/AIDS epidemic,… Xinhua/People’s Daily reports. The World Bank is funding the 18-month project with a $1.6 million grant. The project will train journalists, with a focus on the country’s television and radio stations. Mozambican Prime Minister Luisa Diogo, chair of CNCS, said the media “are crucial to changing people’s behavior and to transforming their attitudes,” adding that it is important that the media sustain HIV/AIDS coverage after the project ends (Xinhua/People’s Daily, 9/14).

National Council for the Fight Against AIDS

“Reprinted with permission from kaisernetwork. You can view the entire Kaiser Daily Health Policy Report, search the archives, or sign up for email delivery at kaisernetwork/dailyreports/healthpolicy. The Kaiser Daily Health Policy Report is published for kaisernetwork, a free service of The Henry J. Kaiser Family Foundation . © 2005 Advisory Board Company and Kaiser Family Foundation. All rights reserved. Continue reading →

As the World Health
Organization (WHO) prepares to announce a dramatic decrease in global AIDS
cases from an estimated high of 39 million people worldwide down to 33
million in a report to be released Wednesday, AIDS Healthcare Foundation
(AHF) questioned whether this newly revised number of people thought to be
living with HIV/AIDS worldwide-now six million fewer-is any more reliable
or accurate than the previous number, and called for greater transparency
among the global bodies such as the World Health Organization that monitor
and track the disease, noting that all these numbers, be they higher or
lower, are guesswork at best.

“Because the vast majority of people who are infected with HIV don’t
know it, there is actually no way to know if this new WHO figure of 33.2
million is any more reliable than the previous estimation of 39 million.
There is certainly no basis for believing that half as many people were
infected this year than last, as is also being reported – especially not
when you can consider that most of the millions of people infected with the
virus are unaware of their positive status and are unknowingly transmitting
the virus to others. These figures are rough numbers based upon
extrapolations gleaned from unreliable data since so few people are being
tested. Let’s stop guessing and make routing testing worldwide a priority,
“said Michael Weinstein, President of AIDS Healthcare Foundation. “There is
certainly reason for skepticism when the numbers shift around so wildly.
Add to that the fact that this latest drop is in part being attributed to a
recent slashing of infection rates in India from nearly 6 million to 3
million-almost too severe a drop to be believed-and it is clear that
greater transparency is needed. Such radical drops in the WHO’s numbers
unfortunately discredits not only the old numbers but the new.”

According to today’s Associated Press, “AIDS Cases Drop, But Mostly Due
to Revised Data,” (Maria Cheng, 11/20/07): “Much of the drop is due to
revised numbers from India – which earlier this year slashed its numbers in
half, from about 6 million cases to about 3 million – and to new data from
several countries in sub-Saharan Africa. Previous AIDS numbers were largely
based on the numbers of infected pregnant women at clinics, as well as
projecting the AIDS rates of certain high-risk groups like drug users to
the entire population at risk. Officials said those numbers were flawed,
and are now incorporating more data like national household surveys. U.N.
officials could not rule out future downward corrections. WHO and UNAIDS
experts reported 2.5 million newly infected people in 2007. Just a few
years ago, that figure was about 5 million

“There has also been no overnight success or significant increase in
safer-sex practices or stepped up availability of condoms around the globe,
further eroding our belief in these newly revised WHO statistics,” added
Weinstein.

About AHF

AIDS Healthcare Foundation (AHF) is the US’ largest non-profit HIV/AIDS
healthcare, research, prevention and education provider. AHF currently
provides medical care and/or services to more than 61,000 individuals in 18
countries worldwide in the US, Africa, Latin America/Caribbean and Asia.
Additional information is available at aidshealth

AIDS Healthcare Foundation
aidshealth Continue reading →

Flu season is upon us and while getting the nasty bug is bad news, the good news is it’s now possible to treat the severe form of the virus more effectively, according to a Ryerson University researcher. Though Canada is not expecting a pandemic flu season this winter Health Canada reports that about 4,000 to 8,000 Canadians die each year from flu-related pneumonia.

Catherine Beauchemin is a professor in the Department of Physics and lead author of the study Neuraminidase inhibitors for treatment of human and avian strain influenza: A comparative modeling study. The study focuses on the treatment of severe influenza-not the kind that produces pesky symptoms such as cough, fever, chills, muscle ache and fatigue, but the kind that leads to acute respiratory illness and possible hospitalization and death.

Traditional flu treatment protocols recommend that neuraminidase inhibitors (NAIs) -drugs that prevent the virus from being released from the cell that produced it-be administered within two days of infection and continued for only five days. Beauchemin, however, found that for the severe form of the virus, treatment with Tamiflu (the most frequently prescribed NAI) can still be effective even when treatment is started as late as six to eight days after infection. The study also found that Tamiflu treatment should be continued beyond five days to prevent the infection from reactivating.

“For severe flu, such as bird flu, people keep getting worse after the two-day mark, and typically show up at the hospital six to eight days after they feel the first symptoms. If they are still very sick at that point this means the virus is still very much at work,” Beauchemin says. “We show that NAI treatment after the two-day mark in these cases is still a valid treatment option. That is, if you’re still producing the flu virus, the treatment will still work.”

The study, which was co-authored by Ryerson postdoctoral fellow Hana Dobrovolny and others, is based on the results of a mathematical model the group created to simulate real flu infections in a patient. The model was used to reproduce data from patients in Vietnam who became infected with bird flu. The model tracked how the flu interacted with two types of cells: those preferred by the virus and easy to infect, and those harder to infect. The latter included cells that are protected by the body’s immune reaction to the virus as well as those cells located in the harder-to-reach lower respiratory tract. While these cells are more resistant to regular flu they can still get infected by more severe flu, such as bird flu. The study explored what happened to an infection when the researchers changed how hard it was to infect the second cell type, and how much virus it went on to produce.

The investigation revealed that in the case of severe infections Tamiflu can be beneficial to patients several days after the initial 48-hour infection window; as long as the drug is taken before the infection’s peak, the medication will substantially shorten the infection’s duration.

The study’s mathematical model is the first of its kind to reproduce both an uncomplicated infection, and a long-lasting, serious virus similar to the bird flu or some of the severe types of swine flu. Now, instead of relying solely on clinical trials-which place limitations on drug-dosage experimentation to protect patients’ health- the mathematical model provides flu researchers with another, more flexible, option for testing the effectiveness of various drug-treatment protocols.

“Severe influenza causes pandemics, so it’s important that we create models for these worst-case scenarios and prepare strategies to deal with them,” Beauchemin says. In the future, findings from Beauchemin’s study may help reduce the flu virus’ impact and improve our use of flu-fighting drugs.

Scheduled to be published in the January 2011 edition of the Journal of Theoretical Biology (currently available ahead of print on the journal’s website), Beauchemin’s “Neuraminidase inhibitors for treatment of human and avian strain influenza: A comparative study” and its sister study titled “Exploring cell tropism as a possible contributor to influenza infection severity” published in the November 2010 edition of PLoS ONE, were funded by the Natural Sciences and Engineering Research Council of Canada and by F. Hoffmann-La Roche, Ltd.

Source:

Ryerson University

View drug information on Tamiflu capsule. Continue reading →

Genetically engineered mice may hold the key to helping scientists from Queensland University of Technology and Harvard hasten the development of a vaccine to protect adolescent girls against the most common sexually transmitted disease, Chlamydia.

Dr Michael Starnbach from Harvard Medical School is in Australia to work with QUT on a joint research project using a “mouse model” to study how the immune system responds to infections such as Chlamydia.”Ultimately the idea is to understand enough about how Chlamydia interacts with cells and how the immune system responds to those infected cells, to be able to understand which components of the immune system need to be stimulated to fight the Chlamydia infection,” Dr Starnbach said.

“At Harvard we have been working on the basic biology of how the immune fighter cells known as T-cells respond to infection.

“When a person is infected with Chlamydia, the organism enters into the outermost cells of the genital tract and stays there and replicates within those cells.

“Once they’re hidden within the cells, only the T-cells can recognise that the cells are infected.

“T-cells are able to recognise cells that are infected and destroy those cells, ultimately eliminating the organism from the body.”

Dr Starnbach said the mouse model being developed by QUT and Harvard would see mice genetically engineered with T-cells that were specifically directed to protect against the mouse strain of Chlamydia.

“In doing this we will be able to learn things about what is involved in protecting mice against Chlamydia infection and then mimic those responses with vaccines,” he said.

Professor Peter Timms along with Professor Ken Beagley, from QUT’s Institute of Health and Biomedical Innovation, are heading a QUT research team working with Dr Starnbach.

“QUT has already identified certain proteins that may be able to be incorporated into vaccines to protect against Chlamydia infection,” Professor Timms said.

“We’ve been testing these proteins and, by working with Harvard, we hope to build on this research.”

Professor Timms said, with rates of Chlamydia infection in some Australian communities as high as 12 per cent of the female population, there was a “real need” to develop a vaccine.

“Chlamydia is the most common sexually transmitted disease in the world and results in infertility in women and long-term chronic pelvic pain,” he said.

“There are antibiotics to treat Chlamydia, but there’s no vaccine to prevent it. In many cases women don’t know they are infected because there are not really any physical signs or symptoms, so by and large they don’t get treatment.”

The project has been supported by a grant from the Harvard Club of Australia Foundation in a program aimed at increasing links between Australian and Harvard-based scientists and building important research collaborations.

Dr Starnbach was one of this year’s four successful applicants for the prestigious Australia-Harvard Fellowships and won it ahead of a highly competitive field. He will be in Australia from 9 October to 12 November 2007.

uq.edu.au Continue reading →

Human Rights Watch at the XVI International AIDS Conference, to be held Aug. 13 through Aug. 18 in Toronto, plans to advocate for “concrete action” by government officials in tackling the main causes of the spread of HIV, including the inequality of women and discrimination against men who have sex with men, commercial sex workers and injection drug users, the group said at a news conference in Toronto on Monday, the Toronto Star reports. Some countries that previously had made progress in fighting their HIV/AIDS epidemics have regressed because of human rights breaches, the group said (Daly, Toronto Star, 7/18). HRW will call on conference delegates, especially officials from the United Nations and the World Health Organization, to set sensible targets for fighting the pandemic and to stop human rights violations against HIV-positive people, according to the CP/Globe and Mail. “Twenty-five years into the epidemic, people living with HIV or AIDS are still feared and stigmatized,” Joe Amon, HRW’s director of HIV/AIDS, said in a statement. He added, “We can’t defeat AIDS unless we end outrageous abuses against activists, outreach workers, people living with AIDS and those most vulnerable to infection.” Amon cited examples of policies that are increasing the spread of HIV, such as Ukraine’s policy to shut down or restrict needle-exchange and methadone programs for IDUs (Ubelacker, CP/Globe and Mail, 7/18). HRW also cited evangelicals as hindrances to tackling the pandemic because of their efforts to curb condom use in Uganda. The group also cited as an obstacle the displacement last year of 700,000 people in Zimbabwe, which interrupted treatment for thousands of HIV-positive people. HIV-positive people and HIV/AIDS advocates around the world also have been subject to murder, assault and arrest, Amon said (Toronto Star, 7/18).

“Reprinted with permission from kaisernetwork. You can view the entire Kaiser Daily Health Policy Report, search the archives, or sign up for email delivery at kaisernetwork/dailyreports/healthpolicy. The Kaiser Daily Health Policy Report is published for kaisernetwork, a free service of The Henry J. Kaiser Family Foundation . © 2005 Advisory Board Company and Kaiser Family Foundation. All rights reserved. Continue reading →

By combining four proteins of Staphylococcus aureus that individually generated the strongest immune response in mice, scientists have created a vaccine that significantly protects the animals from diverse strains of the bacterium that cause disease in humans. A report describing the University of Chicago study, funded by the National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health, appears online this week in the Proceedings of the National Academy of Sciences.

“This finding represents a promising step toward identifying potential components to combine into a vaccine designed for people at high risk of invasive S. aureus infection,” notes Anthony S. Fauci, M.D., NIAID director.

S. aureus, the most common agent of hospital-acquired infection, is the leading cause of bloodstream, lower respiratory tract and skin infections. These infections can result in a variety of illnesses, including endocarditis (inflammation of the heart), toxic-shock syndrome and food poisoning.

Research in S. aureus has taken on new urgency: In the past few decades, the bacterium has developed resistance to traditional antibiotics, thus allowing infections to spread throughout the body of the infected individual despite treatment. More recently, healthy people with no apparent risk factors have been infected by novel and extremely virulent strains of S. aureus acquired from community rather than hospital sources.

Olaf Schneewind, M.D., Ph.D., led the University of Chicago research group. Using available genome sequencing and analysis of antigenic proteins from diverse S. aureus strains, the researchers tested 19 surface proteins to see if they triggered an immune response in mice. The group then identified four individual proteins–IsdA, IsdB, SdrD and SdrE–that provided the strongest immune response, combined them into a vaccine and tested the combination vaccine in mice.

“When we challenged the immunized mice by exposing them to a human strain of S. aureus, the combination vaccine provided complete protection, whereas the control group developed bacterial abscesses,” says Dr. Schneewind. For comparative purposes, the researchers also tested all four proteins as individual vaccines. These vaccines provided either no protection or modest protection, says Dr. Schneewind.

The researchers then tested the combination vaccine in mice again, this time challenging groups of 10 vaccinated mice for seven days using five different S. aureus strains that infect humans. The vaccine offered significant protection against all strains examined.

Dr. Schneewind and his colleagues are now exploring the relationship between antibodies that fight S. aureus infection and surface proteins of the bacterium that facilitate the spread of the infection.

###

NIAID is a component of the National Institutes of Health. NIAID supports basic and applied research to prevent, diagnose and treat infectious diseases such as HIV/AIDS and other sexually transmitted infections, influenza, tuberculosis, malaria and illness from potential agents of bioterrorism. NIAID also supports research on basic immunology, transplantation and immune-related disorders, including autoimmune diseases, asthma and allergies.

The National Institutes of Health (NIH)–The Nation’s Medical Research Agency–includes 27 Institutes and Centers and is a component of the U. S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical and translational medical research, and it investigates the causes, treatments and cures for both common and rare diseases. For more information about NIH and its programs, visit nih/.

Reference: Y Stranger-Jones et al. Vaccine assembly from surface proteins of Staphylococcus aureus. Proceedings of the National Academy of Sciences DOI:10.1073/PNAS.0606863103 (2006).

News releases, fact sheets and other NIAID-related materials are available on the NIAID Web site at niaid.nih/.

Contact: Ken Pekoc

NIH/National Institute of Allergy and Infectious Diseases Continue reading →

A cost-effectiveness analysis of Insite, Canada’s only supervised safe injection site in Vancouver, concludes that it results in $14 million in savings and health gains of 920 life-years over 10 years. The study, published in CMAJ, estimated the number of HIV and Hepatitis C cases that could be prevented with decreased needle sharing, safer injection practices and more referrals to addiction services.

“Vancouver’s supervised injection site is associated with improved health and cost savings, even under conservative estimates of efficacy,” conclude Dr. Ahmed Bayoumi of St. Michael’s Hospital and the University of Toronto, and Gregory Zaric from The Ivey School of Business, University of Western Ontario.

In a related commentary, Dr. Don Des Jarlais of Beth Israel Medical Centre in New York and coauthors question some of the assumptions underlying the analysis and suggest comparisons with programs in New York City. They also point out that almost all effective interventions to reduce HIV infection in Canada will be cost-saving, given that treatment for a single case of HIV infection is estimated at $150,000 (Canadian). Thus, Insite is almost certainly cost-saving to Canadian society.

About CMAJ

CMAJ is the leading health sciences journal in Canada. CMAJ is a general medical journal publishing original research and review articles, commentaries and editorials, practice updates, an arts and ideas section and health news. Published continuously since 1911, new issues are uploaded on cmaj every second Monday at 4:30 p.m. EST/EDT. cmaj contains the complete editorial contents of CMAJ, supplemented by a variety of interactive features and additional content.

CMAJ is an open- and free-access journal – there are no author or page charges and access is provided free on the web (HighWire Press), cmaj without registration. cmaj has about 1 million requests and 250,000 page views per month. The Journal is part of the PubMed Central collection of journals pubmedcentral.nih at the National Library of Medicine thus providing a guarantee of permanent archiving and open access. PubMed Central is now processing back issues of CMAJ to 1911.

CMAJ’s impact factor – a measure of the scientific importance of articles published – has more than tripled since 1997 and is now 7.1.

The Journal receives about 2000 manuscripts a year (including letters to the editor and news articles). CMAJ’s acceptance rate for unsolicited research and review articles is about 12%.

CMAJ Continue reading →

The Papua New Guinea Defence Force will store and distribute 43 million condoms throughout the country in an effort to prevent the spread of HIV, ABC Online reports. ABC Online reports that the National AIDS Council does not have the resources to distribute large amounts of condoms, which in the past has resulted in the expiration of some condoms. The Defence Force will provide storage space in the capital of Port Moresby and transport condoms throughout the country. Commodore Peter Llau said the distribution effort is a worthwhile cause, adding, “We don’t normally deal with civil donor agencies, but this is one of those rare occasions when we’ve responded.” ABC Online reports that an estimated 2% of the country’s population is HIV-positive (Fox, ABC Online, 3/30).

In related news, Member of Parliament Jamie Maxtone-Graham recently said that the country has become complacent in its efforts to control the spread of HIV/AIDS, the Papua New Guinea Post-Courier reports. He said that people should change their attitudes toward the disease as rates of HIV/AIDS in rural areas are increasing rapidly. Maxtone-Graham said that there is no room for complacency, adding that an increasing number of children will be orphaned by the disease. Maxtone-Graham said that as chair of the Special Parliamentary Committee on HIV/AIDS, he will call on other members of parliament to speak out about the disease in their communities (Gerawa, Papua New Guinea Post-Courier, 3/31).

Reprinted with kind permission from kaisernetwork. You can view the entire Kaiser Daily Health Policy Report, search the archives, or sign up for email delivery at kaisernetwork/dailyreports/healthpolicy. The Kaiser Daily Health Policy Report is published for kaisernetwork, a free service of The Henry J. Kaiser Family Foundation.

© 2009 Advisory Board Company and Kaiser Family Foundation. All rights reserved. Continue reading →

Commercial sex workers in Costa Rica will have the opportunity to learn about HIV prevention methods from other sex workers through a new program implemented by a local nongovernmental organization and funded by the World Bank, the EFE/Market Watch reports. Officials with the NGO — called the “La Sala” Association for the Improvement of Quality of Life of Sexual Workers — will train 22 sex workers to deliver messages about prevention, including condom use, and information about the sex workers’ rights. Project coordinator Maria Diaz said the goal of the program is to “empower sexual workers in the matter of prevention.”

The program is expected to have a multiplier effect in the commercial sex work industry and raise awareness among customers, brothel owners and workers. “This part will be difficult,” Diaz said, adding, “What we want is for the (brothel) managers to understand the advantages of having their locales free of HIV and for them to promote them as places where they apply preventive practices.” The program will begin in San Jose and expand to Limon and Puntarenas. The World Bank donated $50,000 to the program (EFE/Market Watch, 1/25).

Reprinted with kind permission from kaisernetwork. You can view the entire Kaiser Daily Health Policy Report, search the archives, or sign up for email delivery at kaisernetwork/dailyreports/healthpolicy. The Kaiser Daily Health Policy Report is published for kaisernetwork, a free service of The Henry J. Kaiser Family Foundation.

© 2009 Advisory Board Company and Kaiser Family Foundation. All rights reserved. Continue reading →