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Common Skin Bacteria Inhibits Antibiotic-Resistant Bacteria

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Infections with antibiotic-resistant bacteria are a growing global problem. Part of the solution may lie in copying the bacteria's own weapons. The research environment in Tromsø has found a new bacteriocin, in a very common skin bacterium. Bacteriocin inhibits the growth of antibiotic-resistant bacteria that are often the cause of disease and can be difficult to treat.

One million deaths each year

The fact that we have medicines against bacterial infections is something many people take for granted. But increasing resistance among bacteria means that more and more antibiotics do not work. When the bacteria become resistant to the antibiotics we have available, we are left without a treatment option for very common diseases. Over one million people die each year as a result of antibiotic resistance.

The first step in developing new antibiotics is to look for substances that inhibit bacterial growth.

Sami name for an exciting discovery

The research group for child and youth health at UiT The Arctic University of Norway has studied substances that the bacteria themselves produce to inhibit the growth of competitors. These substances are called bacteriocins. Through the work, they have discovered a new bacteriocin, in a very common skin bacterium. Bacteriocin inhibits the growth of antibiotic-resistant bacteria that can be difficult to treat with common antibiotics.

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Subscribe for FREE The finding has recently been presented in Microbiology Spectrum.

The researchers have called the new bacteriocin Romsacin, after the Sami name for Tromsø, Romsa. The hope is that Romsacin can be developed into a new medicine for infections for which there is currently no effective treatment.

Long way to go

At the same time, researcher Runa Wolden at the Department of Clinical Medicine at UiT emphasizes that there is a long way to go before it is known whether Romsacin will be developed and taken into use as a new medicine. Because that's how it is with basic research; you cannot say in advance when someone will make use of the results you produce.

"This discovery is the result of something we have been researching for several years. Developing Romsacin - or other promising substances - into new antibiotics is very expensive and can take 10-20 years", says Wolden, who is part of the The research group for child and youth health.

Effective against bacterial types

Before new antibiotics can be used as medicines, one needs to make sure that they are safe to use. Currently, researchers do not know how the bacteriocin works in humans. A further process will involve comprehensive testing, bureaucracy and marketing.

"This naturally means that there is a long way to go before we can say anything for sure. What we already know, however, is that this is a new bacteriocin, and that it works against some types of bacteria that are resistant to antibiotics. It's exciting", says Wolden.

The new bacteriocin is produced by a bacterium called Staphylococcus haemolyticus. The bacteriocin is not produced by all S. Haemolyticus, but by one of the 174 isolates that the researchers have available in the freezer.

"We couldn't know that before we started the project, and that's one of the things that makes research fun", says Wolden.

She says that ten years ago the researchers collected bacterial samples from healthy people when they wanted to compare S. Haemolyticus in healthy people with those found in patients in hospital.

"Subsequently, we have done many experiments with these bacteria, and this is the result from one of our projects", says Runa Wolden.

Reference: Wolden R, Ovchinnikov KV, Venter HJ, Oftedal TF, Diep DB, Cavanagh JP. The novel bacteriocin romsacin from Staphylococcus haemolyticus inhibits Gram-positive WHO priority pathogens. Microbiol Spectrum. 2023:e00869-23. Doi: 10.1128/spectrum.00869-23

This article has been republished from the following materials. Note: material may have been edited for length and content. For further information, please contact the cited source.

Gram-negative Bacteria Are Drug-resistant Superbugs To Watch Out For

We spoke to Dr. Helene Boucher, director of the Infectious Diseases Fellowship Program at Tufts Medical Center and lead author for the Infectious Diseases Society of America report on gram-negative bacteria. Here are some notes:

CNN: Give us an overview.

Dr. Helene Boucher: The big reason that we wrote report at this time is to make a point and try to get some interest in a big problem that we're facing: infections due to gram-negative organisms. MRSA, which most everyone knows about now, is gram-positive. We know about MRSA, but there has been an increase in infections caused by gram-negative bacteria, and they are resistant to many, or sometimes all, drugs. Another point: There has been a decrease in investment in antibiotics to treat these infections, for which we have limited or no treatment options. There is no antibiotic drug in Phase II or beyond, in patients.

CNN: Where is this cropping up? Mostly in hospitals?

Boucher: We see these infections a lot in hospital settings. Acinetobacter is seen in servicemen, Iraq war vets. Vets often have wound infections. There is difficulty with treating them, deformities that they leave. Some people at risk: ICU patients; very young or old patients; people with a lot of other health problems who are already immunocompromised. Some patients who have had a transplant, a burn or some other thing happen to them. We also worry about infection control problems. We saw this in Brooklyn. A lot of infections spread.

CNN: How does this spread in hospitals? Same way as with MRSA?

Boucher: All infections are thus far in hospitals. Most commonly, it spreads from not washing hands when going between patients. We really emphasize hand hygiene. Sometimes doctors call for private rooms for patients who are infected.

CNN: Do you fear that this will become another MRSA? Or worse?

Boucher: It has borne out in Brooklyn, infection gone from rehab centers to nursing homes to hospitals. Patients move around faster: They go to rehab, go home, go to the dialysis center, etc. That's a lot to worry about, where these bugs tend to be moving. The concern is, this could be as bad as, if not worse than, MRSA. At least with MRSA, we have some drugs to treat it.

CNN: What would it take for this to become more like MRSA, to spread into the community?

Boucher: That's a hard question. It takes a bug being strong enough over time. It takes some change that makes it more transmissible. It takes a breakdown in infection control: not washing hands, not paying attention, etc. This bug gets a little "better" over time. With MRSA, it took football players who took whirlpools in same tub, sharing the same towels. Men having sex with men. If you put people factors and bug factors together, then you see the spread. It depends on how "fit" the bug is, how able it is to grow and replicate when gets resistant to antibiotics.

A lot of people are trying to understand this. Some people -- John Bartlett at Johns Hopkins is one scientist -- have predicted a linear increase over time in these infections. We can predict that in several years, we will get a lot worse off. We can't predict whether or when it would end up being something we see in healthy adults, kids, etc.

One thing we have seen is a number of urinary tract infections in women caused by one of these bad bugs; the key is that the women have never been in the hospital, not gotten antibiotics.

CNN: Why haven't we heard about this much until now?

Boucher: Depends on whom you ask: We infectious disease experts have been talking about it. War victims have gotten some press, but this is not a sexy story. The is not always a community interest, unless there's a famous patient/victim, like the Brazilian model.

CNN: The "double membrane" makes it harder to fight these infections; why? Why are they so tough to fight?

Boucher: There are difficult challenges to developing drugs for gram-negative infections. These infections produce a lot of toxins that make people sick fast. Basically, these gram-negative infections make enzymes that chew up antibiotics. Some make enzymes that chew up penicillin or chew up other antibiotics. So you don't have to get an antibiotic that fights one enzyme but multiple enzymes.

Now, these gram-negatives have become resistant to carbapenems; these are the "smartest" antibiotics. It's not likely we're going to find one drug that overcomes every enzyme; it will be more likely a variety of approaches and drugs.

CNN: Are antibiotic drugs hard to get into a clinical study?

Boucher: It's definitely harder than getting drugs for diabetes or obesity, something you take your whole life. Also, there are regulatory hurdles for people trying to make antibiotics. We're trying to make paths more clear for developing new antibiotics. We hope that encourages investment back in this area.

[The National Institutes of Health] this week signaled interest in sponsoring some studies in this area. The NIH hasn't traditionally been into antibiotic development, so that's promising. Government agencies and industry are banding together to get this done. I see that as good news.

CNN: Is this a big public health problem now or on the horizon?

Boucher: This is a public health problem now. The problem is here and now. Doctors have had people in their hospital succumb to these infections. Maybe there is one, and sometimes no, option for treatment.

CNN: Bottom line?

Boucher: We at IDSA advocate a three-pronged strategy for fighting these gram negative infections:

1) Infection control: prevent people from getting an infection in first place.

2) Prudent use of antibiotics: not overusing antibiotics.

3) Developing new antibiotics: generating interest at NIH, CDC, private industry. Get all key stakeholders more involved with developing effective antibiotics to stem infections.

How Dirty Is That Stethoscope? There Are Bacteria That Can Cause Disease

What's on that stethoscope? (Photo: Getty Images)

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Roxette and D.H.T. Sang, "listen to your heart." But if a stethoscope is used to do so, what bacteria may be calling for you?

Determining the types of bacteria found on stethoscopes was the goal of a study just published in the journal Infection Control and Hospital Epidemiology. The abbreviation for this journal is ICHE, which many readers pronounce "itchy." While this study may not make you feel itchy, it could make you feel a little icky.

That's because DNA testing done by a team from the University of Pennsylvania Perelman School of Medicine found lots o' bacteria on stethoscopes used by doctors, nurses, and respiratory therapists in an intensive care unit (ICU). This wasn't just the fun-loving, "I'm OK, you're OK," Barney-type of bacteria. The researchers detected a number of different bacteria types that could cause bad healthcare-associated infections (HAI), such as Staphylococcus aureus. That's not the kind of bacteria that you want hanging around people in the ICU who are very sick and have weakened immune systems.

Of those tested, the stethoscopes with the most bacteria on average were the twenty carried around by doctors, nurses, and respiratory therapists and repeatedly used on different patients. The twenty disposable single-use stethoscopes in patient rooms had comparatively less bacteria. However both types of used stethoscopes had much more bacteria than the ten clean new stethoscopes that were tested.  

Did cleaning these used stethoscopes with hydrogen peroxide wipes, alcohol swabs, or bleach wipes get rid of the unwanted bacterial groupies? Somewhat, but not down to the bacterial levels of spanking new clean stethoscopes.

Are these results really that surprising? In a word, no. In two words, no, no. This certainly wasn't the first study to show that stethoscopes can be covered with bacteria that can cause disease. Just look at the titles of earlier published studies such as "Predictors of Heavy Stethoscope Contamination Following a Physical Examination" and "What's Growing on General Practitioner's Stethoscope?

Previous studies have shown that white coats, neckties, and smartphones can also be covered in... [+] disease-causing bacteria. (Photo: Getty Images)

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Plus, as previous studies, such as this one published in the American Journal of Infection Control, have demonstrated, doctors and other health professionals frequently forget to clean their stethoscopes or use cleaning techniques that are not every effective. What's new about this "itchy" study is that it used molecular analysis to more extensively profile the diverse gangs of bacteria that can live on stethoscopes. Such gangs included Staphylococcus, Pseudomonas, Acinetobacter, Clostridium, Enterococcus, Stenotrophomonas, and Burkholderia species, all of which could cause disease.

What's the scope of this stethoscope issue? Well, healthcare-associated infections (HAIs) continue to be a big problem, as in around $20 billion in healthcare costs each year big. As the Centers for Disease Control and Prevention (CDC) indicates, somewhere between 5% and 10% of all hospitalized patients in the U.S. End up getting some kind of HAI. Each year in U.S. Hospitals, there are approximately 1.7 million HAIs and 99,000 deaths from HAIs.

It is unclear how many of these HAIs are caused by dirty stethoscopes. It can be difficult to pinpoint a stethoscope as the cause of an HAI, because frankly there are a lot of bacteria-covered things in the hospital. For example, a systematic review previously published in ICHE summarized the results of 72 studies that demonstrated common items in the health care settings, such as white coats, neckties, stethoscopes, and mobile electronic devices, are often contaminated with potentially disease causing germs such as Staphylococcus aureus, including methicillin-resistant S. Aureus, gram-negative rods, and enterococci.

This calls for better and more effective ways to clean stethoscopes and help health professionals to do so. For example, a study published in the American Journal of Infection Control suggested that a stronger chemical, chlorhexidine, be used to clean stethoscopes. Other studies have looked at the use of ultraviolet light. Moreover, health professionals may need more time in between patients to make sure that their equipment is clean. In the meantime, if a doctor, nurse, or health professional is about to use a stethoscope on you, you may want to ask if it has been adequately cleaned first. After all, since that stethoscope may go on your chest, there are things that you may want off your chest.

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