Tag Archives: sponge

Kitchen Sponge.

Phages in kitchen sponges could help us wipe antibiotic resistant bacteria clean off

New student research from the New York Institute of Technology (NYIT) could help us stem the tide of antibiotic-resistant infections — using your kitchen sponge.

Kitchen Sponge.

The savior we didn’t want, but the one we need.
Image credits Hans Braxmeier.

Research at the NYIT has zoomed in on bacteriophages — viruses that infect bacteria — living in our kitchen sponges. These biological particles, often shorthanded as ‘phages’, may prove useful in fighting antibiotic-resistant bacteria, the team reports.

Spongy science

“Our study illustrates the value in searching any microbial environment that could harbor potentially useful phages,” said Brianna Weiss, a Life Sciences student at New York Institute of Technology.

Kitchen sponges aren’t exactly the cleanest items in your house. In fact, it’s exposed to all kinds of different microbes every day and is pretty much crawling with a microbiome of bacteria. And where there are bacteria, there are also bacteriophages, viruses that target, infect, and multiply on the back of bacteria.

Students in a research class at NYIT isolated bacteria from their own used kitchen sponges and then used them as bait to see which phages could attack them. Two of the students successfully baited phage strains that could infect these bacteria. The team then decided to ‘swap’ these two phage strains and check whether they could cross-infect the bacteria isolated by the other student — and it turned out they could. The phage strains successfully infected and then killed bacteria recovered from the other sponge.

“This led us to wonder if the bacteria strains were coincidentally the same, even though they came from two different sponges,” said Weiss.

To get to the bottom of things, the team isolated and compared the DNA of these bacterial strains. They report that both belong to the Enterobacteriaceae family, a vast grouping of rod-shaped bacteria that are commonly found in feces. Some members of the Enterobacteriaceae family have been recorded to cause infections in hospital settings. Although related, the researchers do add that lab analysis revealed chemical variations between the two strains.

“These differences are important in understanding the range of bacteria that a phage can infect, which is also key to determining its ability to treat specific antibiotic-resistant infections,” said Weiss.

“Continuing our work, we hope to isolate and characterize more phages that can infect bacteria from a variety of microbial ecosystems, where some of these phages might be used to treat antibiotic-resistant bacterial infections.”

The project fits into a larger drive to develop non-chemical avenues of fighting bacteria. Such measures are meant, on the one hand, to reduce the incidence and spread of antibiotic resistance in bacterial strains by limiting exposure to such drugs. On the other hand, they aim to give us a functioning defense against strains that have already acquired partial or (much worse) complete immunity to our antibiotics. Some of these ideas that we’ve looked at in the past include laying down antibacterialspike pits‘, shredding them with polymers and nanomaterials, using (Komodo) dragon blood, and straight-up causing some bacterial civil war.

Still, the World Health Organization is concerned that, despite drug-resistant bacteria being “one of the biggest challenges mankind has to face in the near, as well as distant future,” and despite these strains claiming hundreds of thousands of lives every year, the world is simply not prepared to deal with the threat. “Only 34 out of 133 questioned countries have even a basic plan to combat the misuse of antibiotics fuelling drug resistance,” Andrei reported at the time.

Hopefully, research such as the one we’re discussing today will mature before our antibiotics become powerless in the face of bacteria. We’re simply over-relying on antibiotics, a study published last May explained, and methods such as the use of phages could help us break the pattern before it is too late.

The findings have been presented at ASM Microbe, the annual meeting of the American Society for Microbiology.


Kitchen sponges are hotspots for bacteria. Sanitizing methods like microwaving don’t seem to work


Microbes love wet environments. They also enjoy food — any kind of nutrients will do since they’re not picky at all. This makes kitchen sponges, which stay wet for most of the time and are packed with leftover scraps, excellent breeding grounds for bacteria. This can turn into a serious health hazard seeing how sponges are supposed to clean the dishes and cutlery that we use to eat. Some studies have suggested that households can reduce the risk of hazardous bacterial infections by sanitizing kitchen sponges.

Some studies have suggested that households can reduce the risk of hazardous bacterial infections by sanitizing kitchen sponges. A new study suggests that these methods aren’t really effective — not even microwaving. Instead, households should turn to cheap sponges that they should replace weekly.

Few places, if any, in our home have more bacterial density then the kitchen sponge

German researchers at the Furtwangen University studied 14 used kitchen sponges separated into top and bottom parts. In total, across all household sponges, the scientists found these yielded 362 operational taxonomic units (OTUs), which are pragmatic proxies for bacterial ‘species’.

After sequencing the cultured bacteria, the researchers ended up with 220,000 raw DNA sequences representing  9 phyla, 17 classes, 35 orders, 73 families, and 118 genera of microbes, as reported by Ars Technica. The most prominent bacteria belonged to the Moraxellaceae family. These are typically found on the human skin and previous studies identified them on virtually every kitchen surface that people typically clean using sponges, from fridges to stoves. These are also the same ‘stinky’ bacteria that make dirty laundry smell bad.

Other notable bacterial species were those belonging to the Proteobacteria, Bacteroidetes, and Actinobacteria phyla. Some of these have been previously identified with moderate diseases.

(A) Kitchen sponges, due to their porous nature (evident under the binocular (B) and water- soaking capacity, represent ideal incubators for microorganisms. Scale bar (B): 1 mm. Credit: Scientifi Reports.

(A) Kitchen sponges, due to their porous nature (evident under the binocular (B) and water- soaking capacity, represent ideal incubators for microorganisms. Scale bar (B): 1 mm. Credit: Scientifi Reports.

In terms of raw numbers, kitchen sponges are teeming with bacteria. The team led by Markus Egert found bacterial densities as high as  5.4 x 1010 or 54 billion-bacterial cells per cubic centimeter of uncleaned kitchen sponge.

“Kitchen sponges are likely to collect, incubate and spread bacteria from and back onto kitchen surfaces, from where they might eventually find their way into the human body, e.g. via the human hands or contaminated food. In addition, direct contact of a sponge with food and/or the human hands might transfer bacteria in and onto the human body, where they might cause infections, depending on their pathogenic potential and the environmental conditions,” the authors wrote in a paper published in Scientific Reports.

Previously, researchers found sanitation through boiling or microwave treatment can significantly reduce the bacterial load of kitchen sponges. Naturally, people regarded the news as a reasonable hygiene measure, which we also covered in detail in the past. Egert argues, however, that these lab studies do not accurately reflect real use. The few sponges that he and colleagues collected from sponge owners who microwaved or hot-soaped them “did not contain fewer bacteria than uncleaned ones.”

Moreover, the bacterial species from the ‘sanitized’ sponges contained more bacteria related to diseases. That may be due to the fact the surviving bacteria are stronger and once they recolonized the sponge, the whole population was more resistant.

“This effect resembles the effect of an antibiotic therapy on the gut microbiota and might promote the establishment of higher shares of RG2-related species in the kitchen sponges. Although further analyses, including controlled sanitation experiments, are needed to substantiate these findings, our data allow careful speculation that a prolonged application of sanitation measures of kitchen sponges is not advisable,” the authors noted.

The paper highlights the fact that used kitchen sponges contain more bacteria than previously thought. It also shows that the “long term perspective, sponge sanitation methods appear not sufficient to effectively reduce the bacterial load in kitchen sponges.” What Egert and colleagues advise instead is to regularly replace kitchen sponges, preferably weekly.

Comb jellie, the phylum Ctenophora, may have been the first creatures on Earth. Credit: Wikimedia Commons.

Comb Jellies may have been the first animals ever

Since 2008, scientists have debated which of the two came first: the sponge (Porifera) or the comb jelly (Ctenophora). A new thorough genetic analysis suggests the latter was Earth’s first animal out of which all other creatures evolved.

Editor’s note: while very similar, comb jellies technically aren’t jellyfish (subphylum Ctenophora vs phylum Medusozoa). The term ‘jellyfish‘ in this article refers to comb jellies. Thanks to Wastrel Way for pointing it out.

Comb jellie, the phylum Ctenophora, may have been the first creatures on Earth. Credit: Wikimedia Commons.

Comb jelly, the phylum Ctenophora, may have been the first creatures on Earth. Credit: Wikimedia Commons.

For more than a century, biologists generally agreed that the first creature to evolve on this planet was a sponge because it’s such a simple creature. The sponge doesn’t have circulatory, nervous, or digestive systems, and only needs water to flow through its pores to survive. After DNA was discovered, and much later when modern genetic sequencing tools appeared, the status of the sponge as the first animal in the world seemed even more cemented. One previous genetic analysis, for instance, showed most genes involved in complex processes are present in sponges. 

The sponge, however, isn’t the only ancient animal at the bottom of all modern creature’s lineage. In 2008, a family-tree study pointed out that the comb jellies came before the sponge, and ever since scientists have been locked in a debate. A recent study which attempted to resolve the early diversification of animal lineages used a massive 1,719-gene dataset with dense taxonomic sampling and found evidence supporting the idea that sponges represent the sister group to all other animals.

While impressive, Antonis Rokas, a biology professor at Vanderbilt University, cautions that such ‘big data’ analyses can still pose phylogenomic contradictions.

“This has worked extremely well in 95 percent of the cases, but it has led to apparently irreconcilable differences in the remaining 5 percent,” Rokas said in a statement.

In a new paper published in Nature Ecology & EvolutionRokas and colleagues employed a new approach to settle 18 controversial phylogenetic relationships, among them the ‘sponge vs comb jellyfish’ debate. In total, the study included seven relationships from animals, five from plants, and six from fungi in order to figure out why so many studies have come up with such conflicting results. To get to the bottom of things, the researchers painstakingly compared the individual genes of the leading contenders in each relationship. That’s hundreds of thousands of genes.

“In these analyses, we only use genes that are shared across all organisms,” Rokas said. “The trick is to examine the gene sequences from different organisms to figure out who they identify as their closest relatives. When you look at a particular gene in an organism—let’s call it A—we ask if it is most closely related to its counterpart in organism B? Or to its counterpart in organism C? And by how much?”

By determining which genes weighed more for a particular hypothesis, like ‘comb jelly came first’, and by labeling the resulting differences as a ‘phylogenetic signal’, the team determined that the comb jelly has significantly more genes which support its ‘first to diverge’ status than the sponge.

Besides jellyfish vs sponges, the researchers also addressed other phylogenetic conflicts like whether crocodiles are more related to birds or turtles. Using the same method, the researchers found 74 percent of the shared genes indicate that crocodiles and birds form sister lineages while turtles are just close cousins.

As to why previous efforts turned out to be so controversial, Rokas suggests the statistical methods used by evolutionary biologists are influenced by ‘strongly opinionated genes’. Only a handful of such genes, which have a strong phylogenetic signal for one of the specific hypotheses, pop up in studies, but these are enough to skew results. For instance, in the case of another controversy surrounding flowering plants and modern birds, the researchers found that removing a single opinionated gene flipped the results from one candidate to another. In this particular case, the team published an inconclusive result either because the available data is inadequate or because the diversification occurred too rapidly to resolve.

“We believe that our approach can help resolve many of these long-standing controversies and raise the game of phylogenetic reconstruction to a new level,” Rokas said.

Of course, that’s not to say this is the final word on the matter. As outlined earlier, it was only in March that a comprehensive genetic analysis gave credence to sponges as the ‘first to diverge’ in favor of the jellyfish. It’s likely that the two will switch roles multiple times before biologists reach a satisfying method. It’s amazing, however, that out of the millions of species that lived on Earth we’re able to single out only two main candidates. That, in itself, is a testimony to how powerful science is.

Ed Barry, Argonne researcher, wrings an Oleo Sponge after a test #sciencecanbemessy. Credit: Mark Lopez/Argonne National Laboratory

Revolutionary material can absorb 90 times its weight in spilled oil. It can be squeezed like a sponge and then reused

A novel material could become the go-to solution for managing scary oil spills that can wreak havoc on the local ecosystem. Thanks to carefully tailored structure, the sponge-like material simply loves to soak in hydrocarbons being capable of absorbing 90 times its weight in crude oil.

Ed Barry, Argonne researcher, wrings an Oleo Sponge after a test #sciencecanbemessy. Credit: Mark Lopez/Argonne National Laboratory

Ed Barry, Argonne researcher, wrings an Oleo Sponge after a test #sciencecanbemessy. Credit: Mark Lopez/Argonne National Laboratory

Although there’s a downward trend in numbers of large oil spills, i.e. greater than 700 tonnes, these are still a major cause of environmental concern. BP’s 2010 spill in the Gulf of Mexico, for instance, spewed  2.5 million gallons of oil a day for months killing hundreds of birds and marine life, as well as the lives 11 crew members. The long-term effects on the Gulf’s fragile ecosystem, however, remain largely unknown — what’s certain is the area is devastated for years.

Cleaning an oil spill is never a pretty or easy job and two oil spills are alike due to variations in oil types, locations, and weather conditions involved. Typically, engineers would first start with containment using booms to confine the spill and skimmer equipment to collect the oil it from the water surface. Large quantities of dispersants are also dumped on the spill to break up the oil and speed its natural biodegradation. Additionally, there are commercially available sorbents specifically designed to absorb oil. These can be effective, depending on the situation, but their main drawback is that they have to be discarded immediately after use, just like you would throw away a paper towel soaked with last night’s mess from the kitchen.

Seth Darling and colleagues at the Argonne National Laboratory in Illinois wanted to make a sorbent that can be used more like a sponge than a paper towel. It consists of polyurethane foam coated with silane molecules which have a chemical affinity of liquid hydrocarbons. The foam, which is commonly found in everything from home insulation to cushions, is littered with ‘nooks and crannies’ where oil molecules can latch on to.

The challenge was to find just the right mix of silane since too little chemical interaction didn’t make the material absorbent and too much kept the oil trapped inside the foam.

They eventually reached a satisfying equilibrium and lab tests suggest the material, called the Oleo Sponge, can be soaked and have its contents squeezed multiple times without any noticeable loss in capacity.

To make sure, though, that these sponge can handle oil spills effectively, Darling and colleagues performed a large-scale test in a giant seawater tank in New Jersey called Ohmsett. The researchers submerged six-square-meter square pads made from Oleo Sponge into the pool, right behind a pipe that was spewing crude oil for the test. After the pads were well soaked, these were sent through a wringer to remove the oil. The process was repeated several times over a couple of days.

“The material is extremely sturdy. We’ve run dozens to hundreds of tests, wringing it out each time, and we have yet to see it break down at all,” Darling said.

All of the tests turned out very promising but the ultimate test is still the high seas. It’s not clear yet if Oleo Sponge can perform well under the high pressure of the deep sea. However, Oleo Sponge is definitely one of those innovative materials that look poised to make a lasting impact.




largest sea sponge

A minivan-sized sea sponge was found by NOAA — the biggest ever

During a deep-sea expedition at  Papahānaumokuākea Marine National Monument, NOAA researchers found a gargantuan 12 foot by 7 foot sponge. It’s the largest any human has come across.


Credit: NOAA Office of Exploration and Research/Hohonu Moana 2015

“The largest portion of our planet lies in deep waters, the vast majority of which has never been explored,” said Papahānaumokuākea research specialist Daniel Wagner, Ph.D, science lead for the expedition with NOAA’s Office of National Marine Sanctuaries. “Finding such an enormous and presumably old sponge emphasizes how much can be learned from studying deep and pristine environments such as those found in the remote Papahānaumokuākea Marine National Monument.”

The natural sea sponge is one of the world’s simplest multi-cellular living organisms, but it’s quite successful considering there are over 5,000 species identified by scientists. These grow in all shapes, sizes, colours and textures.

largest sea sponge

Credit: NOAA Office of Exploration and Research/Hohonu Moana 2015

The smallest species of sea sponge is less than 1 inch long, with the average size of the largest sea sponge being 3 to 6 feet in size.  The previous largest sponge was a  Monoraphus sponge that grew to be over 10 feet wide. Right now, the NOAA researchers aren’t sure what to call the car-sized sponge they found 7,000 feet under the waters off Hawaii.

“It looked like a folded blanket,” Dr Christopher Kelly, a research scientist with NOAA and co-lead for the expedition, told Pacific Beat.

“It looks as though somebody took a blanket and draped it over a chair… so that’s what we called it until we got a better name for it, the folded blanket sponge,” he said.

Sponges grow very slowly, so this specimen is likely very old. Researchers guess it could be anything between a couple centuries and thousands of years old.

“Based on a microscopic examination of spicules, that specimen was identified as belonging to the hexactinellid family Rossellidae and subfamily Lanuginellinae. Aside from these two specimens, we encountered no individuals of this non reef-building species as part of the expedition, during which we conducted a total of 18 ROV dives to depths ranging from 1096 to 4829 m. The finding of such an enormous and presumably old sponge inside the Papahānaumokuākea Marine National Monument underscores the need to protect this area using the highest conservation measures available,” the researchers wrote in the paper published in Marine Biodiversity.

Why you should microwave your sponges, according to science

The best way to keep your sponges clean is to microwave them. We’ll show you why you should do this, and how to do it.

Why microwave sponges

A 2006 study found that kitchen sponges, scrubbing pads, and syringes were easily cleaned of 99 to 100% of all bacteria through simple microwave radiation for only a couple of minutes.

“Basically, what we found is that we could knock out most bacteria in two minutes,” said researcher Gabriel Bitton, professor of environmental engineering at the University of Florida. “People often put their sponges and scrubbers in the dishwasher, but if they really want to decontaminate them and not just clean them, they should use the microwave.”

Kitchen sponges are often in contact with greasy organic matter, and they can get dirty really easily. You’d think that the detergent and cleaning products actually kill the germs, but they really don’t. The odds are kitchen sponges are actually full of germs. In fact, Prof. Charles P. Gerba, a microbiologist, agrees. He writes that sponges are some of the best places in the kitchen for germs, providing a damp and nurturing environment for many different bacteria.

Now, there’s no reason to panic because that’s not the most dangerous thing in the world, but if you want to ensure the cleanliness of your sponges – you should microwave them. According to the study’s results, the total bacterial count was “reduced by more that 99 percent within 1 to 2 minutes, and the sum of coliform and E. coli were totally inactivated after 30 seconds of microwave radiation.” A few more resistant spores lasted up to 4 minutes, and after 10 minutes, there were simply no surviving bacteria in the sponge.

How to microwave your sponge

Odds are, first few times you’ll be doing this you’ll feel silly, but you really shouldn’t.

The process itself is simple and fast, but there are a few basic precautions you should take:

[panel style=”panel-success” title=”Basic precautions” footer=””]- Make sure there’s nothing metallic in your sponge! This can completely ruin the microwave
– Insert the sponge wet, not dry. If it’s dry, it can melt or even catch fire.
– Two minutes kills 99.9% of all bacteria, 10 minutes is overkill and you risk melting the sponge.
– Let the sponge cool off a bit after microwaving it.[/panel]

Other than that, the process is pretty straightforward – you just microwave the sponge. There’s no rule for how often you should do this, but Bitton (the author of the study) says that once a day should be OK.


Kitchen sponges can get dirty and nasty.

There are other alternatives to ensure the cleanliness of your sponges. You could boil them, but that’s neither time nor energy efficient. You can also try to soak them in bleach or vinegar, which is also extremely effective at killing germs, but you need to constantly buy bleach or vinegar. All in all, microwaving is the easiest, fastest and cheapest way to keep your sponges clean.

If you don’t want to do either of the above, you can at least try to clean your sponge after washing the dishes. Then, make sure you dry it and squeeze out as much moisture as possible, and leave it on the sink, not in the sink.

Also, no matter what to do, sponges have to be changed regularly. Otherwise, no matter how hard you try to clean them, they’ll simply get dirty again and lose their qualities.

Simple invention could save many lives – sponge filled syringe receives FDA approval

The average grown man has about 5 liters of blood – and you need most of it to survive. That’s why injured people fall victim not to the wound per se, but to the bleeding caused by it. If we could somehow find a way to stop the bleeding in a timely fashion, then many lives could be saved – and that’s exactly what this invention does.


Image via U.S. Army.

The product is called XStat, developed by a company called RevMedx. XStat is a clear syringe-like container that applies 12-millimeter-wide sponges directly into an open wound. The mechanic process is extremely simple: the sponges absorb blood, they swell up and cling to the wound, ensuring that they stay in place. Enough pressure is applied that the bleeding is temporarily stopped, giving enough time for the patient to reach a medical facility, where surgery can be safely conducted; the entire process takes about 20 seconds. XStat plugs gunshot and shrapnel wounds faster and more effectively than the standard battlefield first aid – let alone what paramedics use. It’ the kind of invention which makes you wonder why no one has thought about it before – it’s so simple yet so effective!

Usually, it takes a pretty long time before the FDA gives its approval for any new product, but thankfully, they moved pretty fast with this one – probably  because it could be so useful in the military.

Up to 3 syringes may be applied to stabilize the bleeding, each containing 92 pill-shaped sponges which measure 9.8 millimeters in diameter and up to 5 millimeters in height and can absorb 3 milliliters of blood – in total, they can absorb almost 0.3 liters of blood. Furthermore, to ensure that no sponge is left behind after the surgery, they all have harmless X-ray markers, which means that a simple X-ray scan can easily detect them following the surgery.

“This will be an important new treatment option for our nation’s military to treat injured soldiers who may not be in close proximity to a medical facility,” FDA’s Christy Foreman says in a news release.
Of course, this needn’t be applied only in the military. A few of these syringes could easily be added to the paramedics’ kit, enabling them to stabilize bleeding patients before transporting them to the ER – which I hope is what will happen.
Via PopSci.