E. Coli

Another Outbreak of TB Linked to Contaminated Bone Grafts

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Urgent need to improve donor screening and product testing, CDC says

A photo of bone allograft material held in tweezers over a beaker.

Contaminated bone allograft material from a single manufacturer led to five diagnosed cases of tuberculosis (TB) and two deaths so far, according to CDC data.

In July, clinicians in two different states rapidly diagnosed and reported two cases of TB in patients who previously underwent spinal surgical procedures that used bone allografts, Jonathan Wortham, MD, from the CDC in Atlanta, and colleagues wrote in the Morbidity and Mortality Weekly Report (MMWR)opens in a new tab or window.

Both clinicians alerted the CDC because the cases looked similar to an outbreak in 2021opens in a new tab or window, involving the same manufacturer. The manufacturer issued a voluntary recallopens in a new tab or window on July 13, 2023. The 2021 outbreak involved 113 patients in 18 states who received contaminated bone allografts.

The bone allografts in this most recent outbreak were from a single deceased donor and were used in 36 recipients. Whole genome sequencing in infected recipients and positive cultures from unused product confirmed that the bone allograft material was the source of the bacteria.

As of December 20, 2023, five recipients had tested positive for TB. An additional 10 had signs or symptoms consistent with TB and 79% had positive interferon-gamma release assay results.

Eight hospitals and five dental offices in seven states received the bone allograft product in question, but the product was rapidly removed from further distribution, the authors wrote, preventing as many as 53 additional procedures with the TB-contaminated material.

The CDC also informed the affected healthcare facilities to quarantine any unused product and implement TB prevention and control measures with affected patients. Patients who received the material were started on multidrug treatment for TB.

The donors from both the 2021 and 2023 outbreaks had evidence of sepsis, which should have made them ineligible for tissue donation, Wortham and investigators commented in the study. The donor from this year’s outbreak also had pneumonia and radiographic changes consistent with a TB diagnosis. Neither donor was tested for TB.

“This second outbreak of bone allograft-related TB in recent years underscores the urgent need to implement improved donor screening and culture-based testing to prevent tissue-derived Mycobacterium tuberculosis transmission,” the authors wrote. Frozen live-cell tissue allografts have expiration dates of months to years after manufacturing, allowing for ample time for both culture-based testing and additional scrutiny of donor medical records, they noted.

The manufacturer involved in both outbreaks did test for M. tuberculosis using nucleic acid amplification before distribution, but this method did not detect the organism, possibly due to low levels of the bacteria. Although nucleic acid amplification tests give more rapid results than culture-based testing, they are less sensitive. Culture-based testing, however, can also yield false-negative results and can take as long as 2 months. In this instance, liquid cultures did not grow M. tuberculosis until 40 days after inoculation, although cultures will usually deliver a positive result in 14 to 21 days, the authors said.

Engineered E. coli Blocks Intestinal Inflammation

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Researchers at Massachusetts General Hospital (MGH) have engineered a strain of the probiotic Escherichia coli (E. coli), Nissle 1917, to secrete proteins of therapeutic value into its surroundings. The engineered strain has the potential to treat intestinal-based diseases.

Their findings are published in Cell Host & Microbe in an article titled, “Engineered Escherichia coli for the in situ secretion of therapeutic nanobodies in the gut.”

“Drug platforms that enable the directed delivery of therapeutics to sites of diseases to maximize efficacy and limit off-target effects are needed,” wrote the researchers. “Here, we report the development of PROT3EcT, a suite of commensal E. coli engineered to secrete proteins directly into their surroundings.

“Many pathogenic relatives of E. coli directly transport bacterial proteins across their outer envelope into human cells using a syringe-like machine,” said senior author Cammie F. Lesser, MD, PhD, a physician-scientist in the infectious disease division at MGH, associate professor of medicine at Harvard Medical School, and d’Arbeloff MGH research scholar.

Lesser’s lab at MGH has been studying these complex protein secretion systems for more than two decades with the ultimate goal of reengineering them as drug delivery systems.

The lab introduced a version of this secretion system into beneficial E. coli and modified it to secrete proteins into its surroundings. They also engineered a variety of proteins of therapeutic value to be recognized as secreted proteins of this machine. The resulting programmable platform is referred to as PROT3EcT for probiotic type III secretion E. coli.

As proof of the potential therapeutic value of PROT3EcT, Lesser and her colleagues tested the engineered E. coli in a mouse model of inflammatory bowel disease.

PROT3EcT was engineered to secrete nanobodies that bind to and inhibit tumor necrosis factor (TNF) alpha, a pro-inflammatory cytokine, and was as effective in blocking the development of inflammation in the intestines of mice as an injected monoclonal antibody that targets the same cytokine.

“Patients administered these drugs systemically are at risk for developing life-threatening infections as well as lymphoma,” said Lesser. “By using engineered bacteria, it should be possible to deliver these anti-inflammatory antibodies and limit immunosuppression directly to where inflammation is present.”

Lesser and her colleagues are now working on engineering bacterial strains that will secrete therapeutic proteins in response to specific conditions, such as when inflammation begins developing in the gut.

Smartphone sensor can detect dirty water contains any E. coli

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Science: smartphone sensor can detect dirty water contains any E. coli

The quality of the tap water is a key factor for the public health, and innovative gadgets can keep water safe, says the Danish scientists. In Nordic countries, the refreshing glass of tap water brings no pathogenic bacteria but the new smartphone sensor can detect dirty water contains any E. coli.

E.coli in a tap water can pose a public health risk, but existing methods to detect E.coli are slow and often expensive. Thanks to the new technologies, a small biosensor operated from the smartphone can inform us about the containing bad bacteria in a tap water.

Technically, bacteria E. coli is a normal flora of the mammal intestinal track but in tap water, it can also indicate the presence of other pathogens such as other bacteria, viruses, and parasites. To stay healthy, best avoid these bacteria, say the scientists. Rapid monitoring to detect these pathogens early is essential to protect public health, and smartphone sensor can be extremely useful.

A nano detective on your smartphone and how it works

The World Health Organization (WHO) consider drinking water to be safe and clean when it contains absolutely no bacteria—not a single bacterium in 100 millilitres of water.

To check the water, add the tiny magnetic particles, which are designed to seek out and bind E. coli, then just insert a sensor strip in the water sample. This is another magnet that attracts the DNA-magnetic particles, bound to the E. coli. The strip is then inserted into a device that takes an electrochemical measurement and thereby detects any E. coli in the sample.

The Dangers of Raw Milk: Unpasteurized Milk Can Pose a Serious Health Risk

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Milk and milk products provide a wealth of nutrition benefits. But raw milk can harbor dangerous microorganisms that can pose serious health risks to you and your family. According to an analysis by the Centers for Disease Control and Prevention (CDC), between 1993 and 2006 more than 1500 people in the United States became sick from drinking raw milk or eating cheese made from raw milk. In addition, CDC reported that unpasteurized milk is 150 times more likely to cause foodborne illness and results in 13 times more hospitalizations than illnesses involving pasteurized dairy products.

cows and a glass of milk

Raw milk is milk from cows, sheep, or goats that has not been pasteurized to kill harmful bacteria. This raw, unpasteurized milk can carry dangerous bacteria such as Salmonella, E. coli, and Listeria, which are responsible for causing numerous foodborne illnesses.

These harmful bacteria can seriously affect the health of anyone who drinks raw milk, or eats foods made from raw milk. However, the bacteria in raw milk can be especially dangerous to people with weakened immune systems, older adults, pregnant women, and children. In fact, the CDC analysis found that foodborne illness from raw milk especially affected children and teenagers.

“Pasteurized Milk” Explained

Pasteurization is a process that kills harmful bacteria by heating milk to a specific temperature for a set period of time. First developed by Louis Pasteur in 1864, pasteurization kills harmful organisms responsible for such diseases as listeriosis, typhoid fever, tuberculosis, diphtheria, and brucellosis.

Research shows no meaningful difference in the nutritional values of pasteurized and unpasteurized milk. Pasteurized milk contains low levels of the type of nonpathogenic bacteria that can cause food spoilage, so storing your pasteurized milk in the refrigerator is still important.

Raw Milk & Pasteurization: Debunking Milk Myths

While pasteurization has helped provide safe, nutrient-rich milk and cheese for over 120 years, some people continue to believe that pasteurization harms milk and that raw milk is a safe healthier alternative.

Here are some common myths and proven facts about milk and pasteurization:

  • Pasteurizing milk DOES NOT cause lactose intolerance and allergic reactions. Both raw milk and pasteurized milk can cause allergic reactions in people sensitive to milk proteins.
  • Raw milk DOES NOT kill dangerous pathogens by itself.
  • Pasteurization DOES NOT reduce milk’s nutritional value.
  • Pasteurization DOES NOT mean that it is safe to leave milk out of the refrigerator for extended time, particularly after it has been opened.
  • Pasteurization DOES kill harmful bacteria.
  • Pasteurization DOES save lives.

Raw Milk and Serious Illness

Symptoms and Advice

Symptoms of foodborne illness include:

  • Vomiting, diarrhea, and abdominal pain
  • Flulike symptoms such as fever, headache, and body ache

While most healthy people will recover from an illness caused by harmful bacteria in raw milk – or in foods made with raw milk – within a short period of time, some can develop symptoms that are chronic, severe, or even life-threatening.

If you or someone you know becomes ill after consuming raw milk or products made from raw milk – or, if you are pregnant and think you could have consumed contaminated raw milk or cheese – see a doctor or healthcare provider immediately.

The Dangers of Listeria and Pregnancy

pregnant womanPregnant women run a serious risk of becoming ill from the bacteria Listeria which can cause miscarriage, fetal death or illness or death of a newborn. If you are pregnant, consuming raw milk – or foods made from raw milk, such as Mexican-style cheese like Queso Blanco or Queso Fresco – can harm your baby even if you don’t feel sick.

Protect Your Family with Wise Food Choices

Most milk and milk products sold commercially in the United States contain pasteurized milk or cream, or the products have been produced in a manner that kills any dangerous bacteria that may be present. But unpasteurized milk and products made from unpasteurized milk are sold and may be harmful to your health. To avoid getting sick from the dangerous bacteria found in raw milk, you should choose your milk and milk products carefully. Consider these guidelines:/p>

Okay to Eat

  • Pasteurized milk or cream
  • Hard cheeses such as cheddar, and extra hard grating cheeses such as Parmesan
  • Soft cheeses, such as Brie, Camembert, blue-veined cheeses,Queso Fresco cheese and Mexican-style soft cheeses such as Queso Fresco, Panela, Asadero, and Queso Blanco made from pasteurized milk
  • Processed cheeses
  • Cream, cottage, and Ricotta cheese made from pasteurized milk
  • Yogurt made from pasteurized milk
  • Pudding made from pasteurized milk
  • Ice cream or frozen yogurt made from pasteurized milk

Unsafe to Eat

  • Unpasteurized milk or cream
  • Soft cheeses, such as Brie and Camembert, and Mexican-style soft cheeses such as Queso Fresco, Panela, Asadero, and Queso Blanco made from unpasteurized milk
  • Yogurt made from unpasteurized milk
  • Pudding made from unpasteurized milk
  • Ice cream or frozen yogurt made from unpasteurized milk

When in Doubt – Ask!

Taking a few moments to make sure milk is pasteurized – or that a product isn’t made from raw milk – can protect you or your loved ones from serious illness.

  • Read the label. Safe milk will have the word “pasteurized” on the label. If the word “pasteurized” does not appear on a product’s label, it may contain raw milk.
  • Don’t hesitate to ask your grocer or store clerk whether milk or cream has been pasteurized, especially milk or milk products sold in refrigerated cases at grocery or health food stores.
  • Don’t buy milk or milk products at farm stands or farmers’ markets unless you can confirm that it has been pasteurized.

Is Your Homemade Ice Cream Safe?

Each year, homemade ice cream causes serious outbreaks of infection from Salmonella. The ingredient responsible? Raw or undercooked eggs. If you choose to make ice cream at home, use a pasteurized egg product, egg substitute, or pasteurized shell eggs in place of the raw eggs in your favorite recipe. There are also numerous egg-free ice cream recipes available.

Source:www.fda.gov

Drug-resistant “nightmare bacteria” are quickly spreading through US hospitals

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Researchers have found evidence that drug-resistant superbugs, which have been labelled “nightmare bacteria”, are spreading faster and more stealthily inside US hospitals than previously thought.

In the US, the bacteria, known as carbapenem-resistant Enterobacteriaceae(CRE), infect roughly 9,300 people per year, and kill around 600. And now researchers think they might spread from person to person asymptomatically – which explains why doctors are often unable to detect it.

“While the typical focus has been on treating sick patients with CRE-related infections, our new findings suggest that CRE is spreading beyond the obvious cases of disease,” said William Hanag  from the Harvard T. H. Chan School of Public Health.

“We need to look harder for this unobserved transmission within our communities and healthcare facilities if we want to stamp it out.”

CRE are a class of drug-resistant bacteria that are even able to withstand carbapenems – last-resort drugs that are administered after all other antibiotics fail.

Enterobacteriaceae are a large-family of bacteria that include bugs such as Salmonella, E. coli, and Shigella –all of which are common causes of food poisoning and stomach bugs.

When they’re not drug-resistant, these bacteria can easily be treated by antibiotics, but antibiotic resistance has increasingly been spread within the family.

The bacteria are known to thrive in hospitals and long-term care facilities, where they evolve and pass genes back and forth over time, eventually becoming deadly CSE superbugs that drugs cannot treat, and earning the researchers’ title of “nightmare bacteria“.

 

An official report last week showed that a US woman has already died from one superbug – an antibiotic resistant strain of pneumonia (not a type of CSE), which was resistant to all available antibiotics in the US.

Now, Hanage and his colleagues have discovered that CSE superbugs, at least, might be spreading at a much faster rate than expected, and are starting to avoid our normal ‘surveillance’ methods by spreading asymptomatically.

“You know the phrase ‘Shutting the stable door after the horse has bolted?’ The horse has not only bolted, the horse has had a lot of ponies, and they’re eating all our carrots,” Hanage told Helen Branswell at Stat News.

To figure out how rapidly CRE was diversifying and spreading, the team analysedover 250 samples from hospitalised patients in three different Boston-based facilities and one in California.

When finished, they found that CRE populations were way more diverse than previously thought, meaning that drug-resistant genes had spread more rapidly and easily between the strains than expected.

The team called it a “riot of diversity“.

Sometimes the species they found didn’t even carry the genes known to supress carbapenems, but  were still able to survive them, suggesting that they’ve found new ways to avoid these antibiotics that we don’t even know about yet.

“There are many different ways in which they can be resistant,” Hanage told Stat News.

To make things worse, the team wasn’t able to see a clear pattern of transmission for these CRE strains – the resistance seemed to be spreading even without any obvious cases of illness or infection.

“The best way to stop CRE making people sick is to prevent transmission in the first place,” Hanage said.

“If it is right that we are missing a lot of transmission, then only focusing on cases of disease is like playing Whack-a-Mole; we can be sure the bacteria will pop up again somewhere else.”

The team hypothesises that these transmissions might be happening from person to person asymptomatically, though they will need to carry out further studies to verify this is the case.

TRUST YOUR GUT: E. COLI MAY HOLD ONE OF THE KEYS TO TREATING PARKINSON’S

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E. coli usually brings to mind food poisoning and beach closures, but researchers recently discovered a protein in E. coli that inhibits the accumulation of potentially toxic amyloids—a hallmark of diseases such as Parkinson’s.

Amyloids are formed by proteins that misfold and group together, and when amyloids assemble at the wrong place or time, they can damage brain tissue and cause cell death, according to Margery Evans, lead author of the University of Michigan study, and Matthew Chapman, principal investigator and associate professor in U-M Molecular, Cellular, and Developmental Biology.

The findings could point to a new therapeutic approach to Parkinson’s disease and a method for targeting amyloids associated with such neurodegenerative diseases.

A key biological problem related to patients with Parkinson’s is that certain proteins accumulate to form harmful amyloid fibers in brain tissues, which is toxic to cells and causes cell death.

While these amyloids are a hallmark of Parkinson’s and other diseases such as Alzheimer’s, not all amyloids are bad. Some cells, those in E. coli included, assemble helpful amyloids used for cell function.

E. coli make amyloid curli on the cell surface, where it’s protective, rather than toxic. The curli anchor the bacteria to kitchen counters and intestinal walls, where they can cause infections and make us sick. These helpful amyloids that E. coli produce do not form on the inside of the cell where they would be toxic.

“It means that something in E. coli very specifically inhibits the assembly of the amyloid inside the cell. Therefore, amyloid formation only occurs outside the cell where it does not cause toxicity,” said Evans, a doctoral student in molecular, cellular, and developmental biology.

Evans and the U-M team went on a biochemical hunt to understand how E. coli prevented amyloids from forming inside cells and uncovered a protein called CsgC that is a very specific, effective inhibitor of E. coli amyloid formation.

U-M researchers have been collaborating with scientists from Umeå University in Sweden and Imperial College in London, and in the current study found that the CsgC protein also inhibits amyloid formation of the kind associated with Parkinson’s.

Another implication of the research is that the curli could be a target for attacking biofilms, a kind of goo created by bacteria, which acts as a shield to thwart antibiotics and antiseptics. These bacteria can cause chronic infections, but treating these infections using molecules that block curli formation may degrade the biofilm and leave the bacteria more vulnerable to drug therapy.

The study, “The bacterial curli system possesses a potent and selective inhibitor of amyloid formation,” is scheduled to appear Jan. 22 in the online edition of Molecular Cell.

Researchers Trick E. Coli Into Making Propane .

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Considering the costs of building new infrastructure and adapting to unfamiliar power sources, we aren’t likely to stop using fossil fuels anytime soon. What’s the next best solution? Make existing fuels greener and renewable.

That’s the idea behind new work from scientists at Imperial College London and the University of Turku in Finland, who aim to eventually coax photosynthetic bacteria to turn sunlight into propane gas. The technology has a long way to go before it’s commercially viable. But as a first step, the team has managed to trick E. coli, a bacteria found in our digestive system, into creating small amounts of engine-ready propane.

Traditionally, propane is created as a by-product of natural gas and petroleum processing. It’s removed from natural gas to make transport along pressurized pipelines safer, and oil refineries produce it when they break down petroleum into either gasoline or heating oil.

In a three-step process, the scientists used enzymes to first free up fatty acids in E. coli that are normally used in the creation of cell membranes. One of these, butyric acid, was then converted with another enzyme into butyraldehyde—a derivative of butane. Finally, the team transformed the butyraldehyde into propane. Stimulating the converting enzyme with electrons enhances the process, the team found.

Recently described in the journal Nature Communications, the project is in its early stages. But Patrik R. Jones, one of the paper’s authors, says the method is simpler than similar attempts at creating fuel with living organisms. Yeast or bacteria play a role in producing ethanol from sugar or corn, and engineered photosynthetic bacteria create diesel from crops as well. Ethanol is now commonly added to gasoline in the United States, thanks mostly to government subsidies and incentives. But bacteria-derived biodiesel hasn’t yet seen widespread use, due largely to continued issues with costs and efficiency.

“In the case of [photosynthetic] biodiesel, there are many steps in the process, and each of these steps has a penalty in terms of efficiency,” says Jones. “If we could cut down the number of steps, at least theoretically, we could then have a more efficient process.”

The focus on propane as opposed to other fuels also simplifies the process, because propane separates from the organisms’ cells easily due to its compact chemical structure. Ethanol, which can be created from corn, sugar and other crops, needs to be physically separated from water in a process that is energy intensive. Current methods for harvesting diesel fuel from algae involve breaking open their cells and, in doing so, killing the organisms that are making the fuel. With propane, the fuel can be separated without destroying E. coli.

Propane is simple to collect as a gas, and yet easier to safely store than hydrogen, which is very dangerous as a gas, especially when mixed with air. It was also chosen, Jones says, because it’s easy to liquefy for transportation, and it’s compatible with the existing infrastructure. Propane is mostly associated with outdoor grills in the United States, but it’s also used to power forklifts and boat motors. Cars can even be converted to run on propane; the process is fairly common in the United Kingdom, where gas prices are much higher than in the United States.

The team is using E. coli at this stage because it’s simple to work with, Jones says. But eventually, the researchers hope to transplant the process from E. coli into photosynthetic bacteria so that sunlight provides the energy to power the cells, rather than the diet of nutrients that E. coli requires. This will again cut down the number of steps in the process, but there’s a lot of work left to be done before the scientists get to that point.

“Only theoretically perfect or near-theoretically perfect systems will ever have a chance of being commercialized,” says Jones. “That’s why it’s important to try and reach [a process] that works as well as possible.” At the moment, Jones estimates they’ll have to produce 1,000 to 5,000 times more fuel from their process before industry will show an interest. And from that point, more engineering and refinement would have to take place before it could be commercially viable as an alternative to existing fossil fuels.

“Some issues lie in the enzymes we use,” says Jones. “So there will need to be some search for alternative enzymes, or improvement of the enzymes we have, and these will be big projects on their own.”

It’s clear that we won’t be driving cars or grilling burgers using propane produced by bacteria and the sun anytime soon. But in an Imperial College London article, Jones said that he hopes the process will become commercially viable in the next 5 to 10 years.

Even if that estimate is generous, solar-powered propane production may be ready in time to help speed up the switch from dirty fuels to more environmentally friendly alternatives.