Tuesday 16 November 2010

The Insanity Virus

Schizophrenia has long been blamed on bad genes or even bad parents. Wrong, says a growing group of psychiatrists. The real culprit, they claim, is a virus that lives entwined in every person's DNA.

Wednesday 27 October 2010

Bacteria To Blame In Asthma Attacks In Children

Doctors have long known that viral infections can bring about asthma attacks and the shortness of breath, coughing, and wheezing associated with them. But while viral infections cannot be treated, scientists at the Danish Paediatric Asthma Centre (DPAC) at the University of Copenhagen and Gentofte Hospital have discovered that treatable bacterial infections can also cause asthma attacks. The discovery could revolutionise treatment.
The study examined 361 children between the ages of four weeks and three years to determine the presence of viral and bacterial infections during severe asthma attacks. The results conclude that the number of attacks was just as high in children with bacterial respiratory infections as in those with viral infections.
Using antibiotics to treat asthma attacks?

"This indicates that bacteria can exacerbate asthma symptoms even if they aren't infected with a virus," Professor Bisgaard says. "The findings open up an entirely new method for treating severe asthma attacks. We can't treat viral infections, but scientists will now look into whether treatment with antibiotics can help children when they have an asthma attack if they are also suffering from a bacterial infection. Being able to use antibiotics to treat asthma attacks in children would be revolutionary.”

The effects of antibiotics in treating asthma attacks will now be examined in large-scale, clinical study by the DPAC.
Source: University of Copenhagen
Friday, October 08, 2010

Friday 1 October 2010

Papillomavirus infection and the link with cancer

Papillomaviridae are small non-encapsulated viruses with a double-stranded DNA circular genome of approximately 8 kbp. Papillomavirus (PV) DNA has been recovered from the skin and lesions of many mammalian species. Moreover, PVs or their genetic material have also been found in birds and turtles. Many PVs seem to cause asymptomatic infections and have been recovered from the healthy skin of many mammals. Negative results in certain mammals could reflect inadequacies in experimental techniques or extinction/sorting events in certain host species. Other PVs induce conspicuous infections of the epithelia and give rise to hyperkeratotic lesions, such as plantar and hand warts in humans caused by HPV1, oral warts in dogs caused by CPV1 and horny warts in the cottontail rabbit caused by SfPV1. Infections by particular human PVs, such as HPV6 and HPV11, cause genital warts and are among the most common sexually transmitted infections.

Infectious agents can account for 20% of the global cancer burden. Several PVs are recognized by the World Health Organization as human carcinogens, as the link between cancer of the cervix and infection by so-called ‘high-risk’ human PVs (e.g. HPV16 or HPV18) is well established. World estimations in 2004 attribute more than 270,000 deaths to cervical cancer, 85% of them in developing countries (http://www.who.int/hpvcentre/en/). Globally, PVs account for more than 30% of all infection-associated cancers in humans, as they are also putatively involved in cancers of the penis, vagina, vulva, anus, perianal region and head and neck. The 2008 Nobel Prize in Physiology and Medicine awarded to Harald zur Hausen “for his discovery of human papilloma viruses causing cervical cancer” acknowledges the importance of this connection (http://nobelprize.org/nobel_prizes/medicine/laureates/2008/). Two vaccines using capsid proteins as immunogens from the most clinically relevant human PVs that cause cervical cancer have been recently licensed and seem to offer at least mid-lasting protection (4–6 years). Certain PV-related malignancies could thus become preventable diseases, but projections for 2030 still foresee more than 470,000 deaths and almost 4 million years of life lost due to cervical cancer in the absence of a widespread application of human PV vaccines (http://www.who.int/healthinfo/global_burden_disease/projections/en/index.html).

From: The clinical importance of understanding the evolution of papillomaviruses. Ignacio G. Bravo, Silvia de Sanjosé and Marc Gottschling. Trends in Microbiology. Volume 18, Issue 10, October 2010, Pages 432-438.

Friday 13 August 2010

NDM-1 Superbug

Recently, alarm has been raised over the spread of drug resistance to carbapenem antibiotics among coliforms (E.coli and Klebsiella), due to production of an enzyme named NDM-1 (or New Delhi Metallo-beta-lactamase).

Carbapenems are a class of beta-lactam antibiotics that have broad spectrum activity and are often reserved for emergency use and 'last resort' treatment. They have a structure that renders them highly resistant to beta-lactamases found in antibiotic resistant bacteria. Resistance to the carbapenems is found throughout India.

Wednesday 7 July 2010

Bags for life could have E. coli

Tests on shoppers’ bags revealed half contained traces of E.coli, a lethal toxin which killed 26 people in Scotland in 1996 in one of the worlds worst food poisoning outbreaks.

Scientists also found many were contaminated with salmonella.

Reusable plastic shopping bags have become increasingly popular in Britain thanks to supermarkets and other retailers giving out millions of free ones to shoppers in the last three years.

It is estimated that there are "hundreds of millions" of bags for life in use in Britain, according to sources within Wrap, the Government's anti-waste watchdog. Because the vast majority of people do not wash their bags after each shopping trip, they could be putting themselves at risk.

The tests were undertaken by the University of Arizona, whose researchers stopped a total of 84 shoppers to check the state of their bags.

The researchers warned the levels of bacteria they found were high enough to cause a wide range of serious health problems and even death.

Children may be in the greatest danger, they added, as they are particularly vulnerable to the effects of organisms such as E.coli.

Many of the bags for life are made from jute or woven polypropylene, helping to reduce the amount of so-called "virgin plastic" used in carrier bags by 40 per cent in just the last three years.

But while they are better for the environment, the new research suggests they could be harmful to health if not cleaned regularly.

Professor Charles Gerba, who led the study said: “Our findings suggest a serious threat to public health, especially from bacteria such as E.coli, which were detected in half of the bags sampled.

“Consumers are alarmingly unaware of these risks and the critical need to sanitise their bags on a weekly basis.”

A poll revealed 97 per cent of shoppers who used eco-friendly bags never washed or bleached them.

E. coli is a species of bacterium found in the intestines of animals and humans. It is passed on through faeces and can survive in the environment.

It is usually transferred to humans by ingesting contaminated water, or contaminated food, such as meat, which has not been cooked properly.

A particularly nasty strain, known as E. coli 0157, can be lethal for children and older people and fewer than 100 of the tiny organisms can cause illness.

Most cases of E. coli in Britain are caused by children coming into contact with animal faeces. Cases are on the increase according to the Health Protection Agency, which said that there were 25,532 reported cases in 2009, a 7 per cent increase compared with 2008.

Ten children last year were admitted to hospital after an outbreak at a petting farm in Surrey.

A spokesman for Wrap said: “Recently there have been concerns in the press that there are health risks from reusing shopping bags in relation to poor hygiene. WRAP recommends that only clean bags in a good state of repair are used and that bags contaminated with food should be cleaned before reusing. Bags that are in poor state of repair should be recycled at carrier bag recycling points.”

Source: telegraph.co.uk By Harry Wallop, Consumer Affairs Editor Published: 6:03PM BST 30 Jun 2010

Friday 2 July 2010

Hazardous morning shower

Daily Bathroom Showers May Deliver Face Full of Pathogens, Says CU-Boulder Study

While daily bathroom showers provide invigorating relief and a good cleansing for millions of Americans, they also can deliver a face full of potentially pathogenic bacteria, according to a surprising new University of Colorado at Boulder study.

The researchers used high-tech instruments and lab methods to analyze roughly 50 showerheads from nine cities in seven states that included New York City, Chicago and Denver. They concluded about 30 percent of the devices harbored significant levels of Mycobacterium avium, a pathogen linked to pulmonary disease that most often infects people with compromised immune systems but which can occasionally infect healthy people, said CU-Boulder Distinguished Professor Norman Pace, lead study author.

It’s not surprising to find pathogens in municipal waters, said Pace. But the CU-Boulder researchers found that some M. avium and related pathogens were clumped together in slimy “biofilms” that clung to the inside of showerheads at more than 100 times the “background” levels of municipal water. “If you are getting a face full of water when you first turn your shower on, that means you are probably getting a particularly high load of Mycobacterium avium, which may not be too healthy,” he said.

The study appeared in the Sept. 14 online edition of the Proceedings of the National Academy of Sciences. Co-authors of the study included CU-Boulder researchers Leah Feazel, Laura Baumgartner, Kristen Peterson and Daniel Frank and University Colorado Denver pediatrics department Associate Professor Kirk Harris. The study is part of a larger effort by Pace and his colleagues to assess the microbiology of indoor environments and was supported by the Alfred P. Sloan Foundation.

Research at National Jewish Hospital in Denver indicates that increases in pulmonary infections in the United States in recent decades from so-called “non-tuberculosis” mycobacteria species like M. avium may be linked to people taking more showers and fewer baths, said Pace. Water spurting from showerheads can distribute pathogen-filled droplets that suspend themselves in the air and can easily be inhaled into the deepest parts of the lungs, he said.

Symptoms of pulmonary disease caused by M. avium can include tiredness, a persistent, dry cough, shortness of breath, weakness and “generally feeling bad,” said Pace. Immune-compromised people like pregnant women, the elderly and those who are fighting off other diseases are more prone to experience such symptoms, said Pace, a professor in the molecular, cellular and developmental biology department.

The CU-Boulder researchers sampled showerheads in homes, apartment buildings and public places in New York, Illinois, Colorado, Tennessee and North Dakota.

Although scientists have tried cell culturing to test for showerhead pathogens, the technique is unable to detect 99.9 percent of bacteria species present in any given environment, said Pace. A molecular genetics technique developed by Pace in the 1990s allowed researchers to swab samples directly from the showerheads, isolate DNA, amplify it using the polymerase chain reaction, or PCR, and determine the sequences of genes present in order to pinpoint particular pathogen types.

“There have been some precedents for concern regarding pathogens and showerheads,” said Pace. “But until this study we did not know just how much concern.”

During the early stages of the study, the CU team tested showerheads from smaller towns and cities, many of which were using well water rather than municipal water. “We were starting to conclude that pathogen levels we detected in the showerheads were pretty boring,” said Feazel, first author on the study. “Then we worked up the New York data and saw a lot of M. avium. It completely reinvigorated the study.”

In addition to the showerhead swabbing technique, Feazel took several individual showerheads, broke them into tiny pieces, coated them with gold, used a fluorescent dye to stain the surfaces and used a scanning electron microscope to look at the surfaces in detail. “Once we started analyzing the big metropolitan data, it suddenly became a huge story to us,” said Feazel, who began working in Pace’s lab as an undergraduate.

In Denver, one showerhead in the study with high loads of the pathogen Mycobacterium gordonae was cleaned with a bleach solution in an attempt to eradicate it, said Pace. Tests on the showerhead several months later showed the bleach treatment ironically caused a three-fold increase in M. gordonae, indicating a general resistance of mycobacteria species to chlorine.

Previous studies by Pace and his group found massive enrichments of M. avium in “soap scum” commonly found on vinyl shower curtains and floating above the water surface of warm therapy pools. A 2006 therapy pool study led by Pace and CU-Boulder Professor Mark Hernandez showed high levels of M. avium in the indoor pool environment were linked to a pneumonia-like pulmonary condition in pool attendants known as “lifeguard lung,” leading the CU team into the showerhead study, said Pace.

Additional studies under way by Pace’s team include analyses of air in New York subways, hospital waiting rooms, office buildings and homeless shelters. Indoor air typically has about 1 million bacteria per cubic meter and municipal tap water has rough 10 million bacteria per cubic meter, said Pace.

So is it dangerous to take showers? “Probably not, if your immune system is not compromised in some way,” said Pace. “But it’s like anything else -- there is a risk associated with it.” Pace said since plastic showerheads appear to “load up” with more pathogen-enriched biofilms, metal showerheads may be a good alternative.

“There are lessons to be learned here in terms of how we handle and monitor water,” said Pace. “Water monitoring in this country is frankly archaic. The tools now exist to monitor it far more accurately and far less expensively that what is routinely being done today.”

In 2001 the National Academy of Sciences awarded Pace the Selman Waxman Award -- considered the nation’s highest award in microbiology -- for pioneering the molecular genetic techniques he now uses to rapidly detect, identify and classify microbe species using nucleic acid technology without the need for lab cultivation. That same year he was awarded a MacArthur Foundation “genius grant” for his work.

A video news release on the showerhead and pathogen study is available at: http://link.brightcove.com/services/player/bcpid1859735479?bctid=40087152001

Contact

Norman Pace, 303-735-1864

Norman.Pace@colorado.edu

Jim Scott, 303-492-3114

Jim.Scott@colorado.edu

Monday 14 June 2010

Legionella Risk in Windscreen Water

Windscreen wiper water may be the cause of 20% of cases of Legionnaires' Disease in England and Wales, the Health Protection Agency says.

Stagnant, warm water is a breeding ground for the Legionella bacterium, which when inhaled causes pneumonia. Yet adding screenwash kills the bacteria and could save lives, the Agency advised. The finding came after researchers spotted that professional drivers are five times more likely to be infected.

Legionnaires' disease is fairly rare. Most cases are sporadic and a source of the infection is not found. The number of cases vary from year to year, but in 2009 there were 345 in England and Wales - although some infections were caught overseas. It mainly affects the over 50s and is generally more common in men. Early symptoms feel similar to flu with muscle aches, tiredness, headaches, dry cough and fever. It is fatal in around 10-15% of patients.

Driving

To work out why people who spend a long time driving were at higher risk of infection, the research team in the south-west branch of the HPA carried out a questionnaire of people infected. They found that those most at risk were those who drove or travelled in a van, those who drove through industrial areas, and those who spent a lot of time in the car or who often had the car window open. In all they found that the biggest risk was associated with not adding screenwash to windscreen wiper water, the European Journal of Epidemiology reports.

In a pilot study carried out by the HPA, traces of Legionella were found in one in five cars that did not have screenwash, but in no cars that did. Dr Isabel Oliver, regional director of the HPA South West, said more research was needed but people may want to check they have screenwash in their cars as they usually contain agents which would stop the growth of bacteria. "It does not spread from person to person but is present in water environments and is breathed in when it gets into the air in fine particles or mist."

Professor Hugh Pennington, an expert in bacteriology, said the advice to add screenwash was very sound - especially as it would also lead to a cleaner windscreen. "This is a bug which lives in the environment and will take advantage of warm water systems that are not cleaned out. "Legionnaires' is rare but it kills people and it's an extremely unpleasant disease. "If you can prevent it with something this simple then it's a no brainer really."

By Emma Wilkinson, Health reporter, BBC News, 13 June 2010

Thursday 20 May 2010

Microbes on and in the human body

A major initiative by the U.S. National Institutes of Health to sequence 900 genomes of microorganisms that live on the surfaces and orifices of the human body has established standardized protocols and methods for such large-scale reference sequencing. By combining previously accumulated data with new data, Nelson et al. present an initial analysis of 178 gbacterial genomes. The sampling so far barely scratches the surface of the microbial diversity found on humans, but the work provides an important baseline for future analyses.
http://www.sciencemag.org/cgi/content/abstract/328/5981/994

Thursday 25 February 2010

LEGIONELLA, SPRINGTIME AND POTTING SOIL

B de Jong ()1, P Zucs1
  1. European Centre for Disease Control and Prevention, Stockholm, Sweden
Citation: de Jong B, Zucs P. Legionella, springtime and potting soils. Euro Surveill. 2010;15(8):pii=19497. Available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19497

Date of submission: 25 February 2010

Legionnaires’ disease has been named after the outbreak in Philadelphia 1976 when a mysterious pneumonia affected a large number of members of the American Legion, a United States military veterans association, which held a gathering at a hotel [1]. Legionella, the bacterium causing the disease was identified several months after this outbreak for the first time. Today we know that there are about 50 different species of Legionella and that not all of them seem to be pathogenic to humans. The vast majority of reported cases are infected with L. pneumophila by inhalation of aerosols (water droplets) containing the bacteria, which is the route of infection for most Legionella cases. This is also described in an article by Joseph and Ricketts in this issue [2]. 

However, in some instances cases are infected by other Legionella species. A second paper in this issue describes a possible association between handling potting soil and infection with L. longbeachae [3]. As pointed out by the Scottish authors, this has long been well known and documented in Australia and New Zealand. In a soil survey performed in 1989 to 1990 in Australia, 33 (73%) of 45 potting soil samples tested positive for Legionella; 26 (79%) of the 33 contained L. longbeachae [4].
On their homepage, the Auckland Regional Public Health Service as well as the other public health services in Australia and New Zealand offers the following advice on how to minimise the risk of contracting legionellosis [5]:
  • Take care when dealing with compost, potting mix and any form of soil or dirt. Read the warning labels on commercially available bags of compost and potting mix.
  • To minimise risk, avoid stirring up dust, avoid inhaling dust, dampen the soil/compost before use, wear a dust mask that fits tightly over nose and mouth.
As the Scottish paper indicates, these recommendations may nowadays also be valid in Europe. Cases of L. longbeachae infections often appear as single cases and it could prove difficult to find a link with a commercial potting soil.
According to Steele et al., potting soils are made from different products [4].  In Australia, they tend to consist of composted waste products such as sawdust and hammer milled bark while in Europe peat moss is a major component. It is indicated that the use of different products emanating from wood could facilitate the occurrence of different Legionella bacteria in potting soil. In some parts of Europe, potting soils have bark soil as a component. However, studies from Switzerland have shown that Legionella spp. could also be present in potting soil containing peat moss [6].
Spring will soon come, and with the milder temperatures and increasing amounts of sunlight, gardeners all over Europe will start planting seeds and growing flowers and vegetables. These activities may involve contact with different potting soils and their dust, possibly giving rise to Legionnaires’ disease. In this light of spring, cases should not only be questioned about their travel history and contact with aerosols but also if they have had any contact with potting soils or done any gardening.  

Clinicians seeing patients with atypical pneumonia should be aware that the Legionella urinary antigen test is only valid for detection of Legionella pneumophila serogroup 1 and therefore other samples should be collected from the patient and submitted to the laboratory in order to be able to identify the causative agent.
In order to be able to estimate how many cases of Legionnaires’ disease in Europe are attributable to potting soil, more clinical samples and samples from incriminated potting soils should be cultured. Besides gaining new insight into the epidemiology of this serious disease, the source of each infection could be traced, thus reducing the risk of subsequent cases occurring.

References

  1. Fraser DW, Tsai TR, Orenstein W, Parkin WE, Beecham HJ, Sharrar RG, et al. Legionnaires’ disease: description of an epidemic of pneumonia. N Engl J Med. 1977;297(22):1189-97.

  2. Joseph CA, Ricketts KD, on behalf of the European Working Group for Legionella Infections. Legionnaires’ disease in Europe 2007–2008. Euro Surveill. 2010;15(8):pii=19493. Available from: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19493

  3. Pravinkumar SJ, Edwards G, Lindsay D, Redmond S, Stirling J, House R, et al. A cluster of Legionnaires’ disease caused by Legionella longbeachae linked to potting compost in Scotland, 2008-2009. Euro Surveill. 2010;15(8):pii=19496. Available from: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19496

  4. Steele TW, Moore CV, Sangster N. Distribution of Legionella longbeachae serogroup 1 and other Legionella in potting soils in Australia. Appl Environ Microbiol. 1990;56(10):2984-8.

  5. Fact Sheet – Legionellosis. New Zealand: Auckland Regional Public Health Service (ARPHS). Available from: www.arphs.govt.nz/notifiable/downloads/legionellosis.pdf

  6. Casati S, Giora-Martinoni A, Gaia V. Commercial potting soils as an alternative infections source of Legionella pneumophila and other Legionella species in Switerland. Clin Microbiol Infect. 2009;15(6):571-5.

Wednesday 6 January 2010

Drug-Resistant Acinetobacter Infection Triples in U.S. Hospitals

Cases of a type of drug-resistant bacteria especially common among Iraqi war veterans have tripled in U.S. hospitals, researchers reported on Wednesday.
They found a 300% increase in cases of Acinetobacter that are resistant to imipenem.
"The findings are troubling because they suggest this bacteria is becoming resistant to nearly everything in our arsenal," said Ramanan Laxminarayan of Resources for the Future, a think-tank examining the issue.
He and his colleagues reported on drug-resistant Acinetobacter in Infection Control and Hospital Epidemiology. Their data came from 300 hospitals around the United States.
"There is a lot of attention on MRSA, but less on infections caused by bacteria like Acinetobacter for which there are fewer drugs in the development pipeline," Laxminarayan said.
Infection Control and Hospital Epidemiology 2009.