Using a Virus to Fight Bacteria

Dennis Thompson wrote . . . . . . . . .

Viruses and bacteria are the culprits behind the infectious diseases that plague humans. Researchers recently turned one against the other, using viruses to wipe out a potentially life-threatening bacterium in a 15-year-old girl with cystic fibrosis.

This old-time approach to battling bacterial infections might be worth another look in these days of antibiotic-resistant bacteria, a new paper argues.

Genetically engineered bacteriophages — viruses that infect and kill bacteria — successfully cleared up a severe antibiotic-resistant bacterial infection in the critically ill teenager, researchers said in a new study.

“This is the first use of ‘phages’ to treat this kind of infection with this kind of bacterium, and it’s the first time that anyone’s used ‘phages’ that have been genetically engineered to be more effective,” said study co-author Graham Hatfull. He’s a professor of biotechnology at the University of Pittsburgh.

The idea of using bacteriophages to battle human disease has been around for about a century. But it fell out of favor in the 1940s with the discovery of penicillin and other antibiotics, according to the BioTherapeutics Education & Research Foundation.

The notion of bacteriophage therapy is getting a second look now that some dangerous bacteria are developing resistance to widely used antibiotics.

In this case, a cocktail of three phages wiped out an infection of Mycobacterium abscessus that had plagued the young girl for eight years, then flared up after she underwent a double lung transplant as a result of cystic fibrosis.

“Mycobacterium abscessus — a bacterium that is one of the most daunting to treat — is in desperate need of effective therapies,” said Dr. Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security in Baltimore.

“That this patient had a very positive response to intravenous phage therapies is an important milestone and hopefully will lead to more use of phages for this specific infection and for others,” said Adalja, who was not involved in the study.

“The antibiotic pipeline is rapidly running dry and the use of bacteriophages is increasingly proving to be one important solution to the looming infectious disease crisis the world faces,” he added.

The lung transplant occurred without any immediate problems, but afterward the patient was put on immunosuppressive drugs to help the body adapt to the new lungs, researchers said.

That gave the long-standing bacterial infection a chance to become widespread, despite treatment with multiple intravenous antibiotics.

The girl’s surgical wound site became infected, the liver became inflamed, and sores erupted on more than 20 locations on her legs, arms and buttocks, researchers said.

“The patient was not responding to antibiotics,” Hatfull said. “Our expertise is in the study of the bacteriophages, so we sought to try to find phages in our collection which would infect and kill this particular bacterial strain.”

Researchers wound up identifying three different phages that might effectively kill off the bacteria. They genetically improved the viruses to make them better able to tackle the infection.

They administered the phages intravenously and topically to the infected skin lesions. Within six months, the surgical wound and skin lesions healed, with no adverse effects, researchers said.

Bacteriophage therapy holds huge promise because it only attacks the specific bacteria it considers the enemy, Hatfull said.

“That specificity is in marked contrast to antibiotics, which often just blast away any of the bacteria in your body,” Hatfull said.

But that specificity is a drawback as well.

“They’re often so specific that even though they may infect and be useful for the strain that infects one patient, they may not attack very similar bacteria that infect other patients,” Hatfull said. “That’s really the conundrum with the use of the phages more broadly.”

Genetic research into phages and how they choose their targets could help open up bacteriophage therapy as an alternative to antibiotics, Hatfull said.

“If we could understand that at a basic research level, perhaps then we would be able to extend what appears to be a good outcome for one patient into a treatment that would be more broadly useful for more patients,” Hatfull said.

The study results appear online in the journal Nature Medicine.

Source: HealthDay


Read also at npr:

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“Bugs” in the Gut Might Predict Dementia in the Brain

The makeup of bacteria and other microbes in the gut may have a direct association with dementia risk, according to preliminary research to be presented in Honolulu at the American Stroke Association’s International Stroke Conference 2019, a world premier meeting for researchers and clinicians dedicated to the science and treatment of cerebrovascular disease.

Researchers studying the population of bacteria and microbes in the intestines, known as gut microbiota, have found these “bugs” impact risks for diseases of the heart and more. Japanese researchers studied 128 (dementia and non-dementia) patients’ fecal samples and found differences in the components of gut microbiota in patients with the memory disorder suggesting that what’s in the gut influences dementia risk much like other risk factors.

The analysis revealed that fecal concentrations of ammonia, indole, skatole and phenol were higher in dementia patients compared to those without dementia. But levels of Bacteroides – organisms that normally live in the intestines and can be beneficial – were lower in dementia patients.

“Although this is an observational study and we assessed a small number of the patients, the odds ratio is certainly high suggesting that gut bacteria may be a target for the prevention of dementia,” said Naoki Saji, M.D., Ph.D., study author and vice director of the Center for Comprehensive Care and Research on Memory Disorders, National Center for Geriatrics and Gerontology in Japan.

Source: American Heart Association


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Poo Found on Every McDonald’s Touchscreen Tested in UK

Adam Smith wrote . . . . . . . . .

Traces of faeces have been found on every single McDonald’s touchscreen swabbed in an investigation by metro.co.uk.

Samples were taken from the new machines that have been rolled out at restaurants across the country – every one of them had coliforms.

Senior lecturer in microbiology at London Metropolitan University Dr Paul Matewele said: ‘We were all surprised how much gut and faecal bacteria there was on the touchscreen machines. These cause the kind of infections that people pick up in hospitals.

‘For instance Enterococcus faecalis is part of the flora of gastrointestinal tracts of healthy humans and other mammals. It is notorious in hospitals for causing hospital acquired infections.’ Unsuspecting diners choose their food on the touchscreens then head to the server to pick up their burgers more often than not without washing their hands.

A screen at one branch was found to have staphylococcus, a bacteria that can cause blood poisoning and toxic shock syndrome.

Dr Matewele said: ‘Seeing Staphylococcus on these machines is worrying because it is so contagious. ‘It starts around people’s noses, if they touch their nose with their fingers and then transfer it to the touchscreen someone else will get it, and if they have an open cut which it gets into, then it can be dangerous.

‘There is a lot of worries at the moment that staphylococcus is becoming resistant to antibiotics. However, it is still really dangerous in places like Africa where it can cause toxic shock.’ Metro.co.uk’s study with the university’s school of human sciences involved swabs taken from eight McDonald’s restaurants. Six in London and two in Birmingham.

Listeria bacteria was found in Oxford Street and Holloway Road branches. It can cause listeriosis which can lead to miscarriages and stillbirths in pregnant women. Dr Matewele said: ‘Listeria is another rare bacterium we were shocked to find on touchscreen machines as again this can be very contagious and a problem for those with a weak immune system.’

Three quarters of the screens swabbed showed traces of the bacteria proteus.

Dr Matewele said: ‘Proteus can be found in human and animal faeces. It is also widely distributed in soil. It can cause urinary tract infections and is also one of the hospital acquired infections where it may responsible for septicaemia.

‘Klebsiella is also from the gut and mouth, they are associated with urinary tract infections, septicemia and diarrhoea. Some species can infect the respiratory tract resulting in pneumonia.’

Source: Metro

We All Carry a Personal Cloud of Germs, Chemicals

Amy Norton wrote . . . . . . . . .

You might feel squeaky clean after that morning shower, but you carry an invisible cloud of bacteria, viruses, fungi and chemicals every day.

That’s one of the lessons from the first study to take a deep dive into the human “exposome” — the collection of microbes, plant particles and chemicals that accompanies people as they move through the world.

In fact, if your personal exposome was visible to the naked eye, the researchers said, you’d look like the “Peanuts” character Pig-Pen.

In the study, a small group of volunteers wore monitors with a special filter that trapped particles from the air around them as they went about their normal day.

When researchers did a genetic analysis of those samples, they found that each person carried a diverse cloud of bacteria, viruses, fungi, plant particles, chemicals and even “microscopic animals.”

But the exact makeup of that exposome varied substantially from person to person — even though they lived in a fairly narrow geographic region (the San Francisco Bay area).

“This is a very interesting study,” said Dr. Aaron Glatt, chief of medicine at South Nassau Communities Hospital, in Oceanside, N.Y.

It’s no secret that humans live in a world chock-full of invisible organisms and chemicals, said Glatt, who is also a spokesperson for the Infectious Diseases Society of America.

But this study offers a detailed look at individual exposomes, he said. And that could be a first step toward understanding the ways in which various environmental exposures affect human health, Glatt suggested.

“That’s what we believe,” agreed senior researcher Michael Snyder, chair of genetics at Stanford University School of Medicine, in California.

“Health is totally dependent on genes and environment,” Snyder said. But it’s clear that genes explain only a portion of a person’s vulnerability to various diseases, he added.

There is still a huge amount to be learned about the effects of environmental exposures, Snyder said.

As an initial step, his team gathered detailed information from 14 people who wore matchbook-sized monitors on their arms for anywhere from a week to a month. Snyder, himself, wore the device for two years.

The devices contained filters that captured particulate matter from the surrounding air. Those samples were brought back to the lab for genetic analyses and chemical “profiling.”

In general, Snyder’s team found, people’s exposomes were diverse in the types of micro-organisms and chemicals they contained — although the chemical DEET, an insect repellent, was ubiquitous.

“It was everywhere, which kind of surprised me,” Snyder said.

Otherwise, the makeup of the exposome seemed to depend on factors like weather, travel, pets and household chemicals, for instance.

Snyder said his own home exposures turned out to be “very fungal, rather than bacterial.”

He connects that to the use of “green” paint in his house. The paint lacks a substance called pyridine, which seems to keep fungus levels down. Snyder also discovered he was exposed to eucalyptus in the early spring — which, he said, offers some clues to the culprit behind his seasonal allergies.

Several known carcinogens turned up in most of the chemical samples, according to the researchers. However, they only know the chemicals were present — and not the amount of exposure.

If the idea of carrying around a cloud of bacteria, fungi and chemicals makes you cringe, Glatt made this point: Many of those exposures would be harmless or even beneficial.

It’s known, for instance, that while some bacteria make people sick, many are “good” and necessary for human health.

Snyder agreed. For the most part, no one knows yet which components of the exposome are “good” and which are not, he said. And that may vary from one person to another, he added.

Complicating matters, a person’s exposome is not static. It is “dynamic,” Snyder said, and constantly shifting over a lifetime.

That will make it challenging to study the ways in which the exposome affects human health, Snyder said. “But I also think it can be done,” he added.

He said his team plans to study larger groups of people in more-diverse environments. They also want to simplify the technology used in the study so that one day, people might be able to use the devices themselves, to track their own exposures.

The findings were published online in Cell.

Source: HealthDay

Norway’s Food Safety Authority Warns Not to Eat Raw Oyster from Southern Nordic Fjords

Lefteris Karagiannopoulos wrote . . . . . . . .

The southern Nordic fjords are heating up as Europe boils, and bacteria there are flourishing, infecting swimmers and seafood, including oysters that can take months until they are safe to eat again, Norway’s food safety authority said.

The warm waters in southern Norway and Sweden have accelerated the reproduction of the vibrio bacteria, a species that can cause vibriosis, an illness with symptoms as simple as diarrhea and stomachache but which can also be fatal.

The water in Norway’s southern fjords reached 24 degrees Celsius, about 4C higher than average for the season, and the bacteria in the local sea ecosystem have been traced in much larger quantities than usual.

They have already infected the wounds of several swimmers in the Oslo fjord, where people have arrived in droves to beat the heat, but they can also infect people eating raw seafood, the food safety authority said.

“Eating raw oysters is common for Norwegians. People go to cabins during the summer, dive for oysters and eat them… It can take months for raw oysters to be safe again as the water needs to cool,” the authority’s seafood safety head Lise Rokkone told Reuters.

The fjords are rich with trout and salmon at certain times of year, but eating raw fish should also be avoided, said Rokkone, days after the authority issued an oyster consumption warning.

The extreme heatwave that hit the Nordics this summer has also affected cattle feed, she said, forcing many farmers to either seek feed from Northern Norway or import.

Infected oysters are not however the only heat-related inconvenience Norwegians have to face this summer.

As well as an outdoor barbecue ban barring everyone from heading outside to cook, the number of snake bite incidents has doubled from last year as more people spend time in the forest, while drivers have to be careful in tunnels, where reindeer have taken to sheltering from the heat.

Last week, the Norwegian church even asked believers to light candles and pray for a change in the weather.

Source: Reuters