Thursday, 08 September 2011 10:18

Sorry lab rats: E. coli is still cooler than you

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E. coli K-12 is a lot like your average lab rat: predictable, well-understood, and tame. However, there’s at least one important difference between a white rat and K-12: the rat can’t mutate and become a voracious, man-eating scourge.
Despite the great strides medicine has made in the past century, diagnosing infectious disease remains a difficult – and often impossible – task. One major barrier in diagnosis is the simple problem of knowing what to look for. Which of the millions of potentially antigenic products that a pathogen makes can actually be found in bodily fluids and used as indicators of infection? After all, not every protein or polysaccharide belonging to a pathogen can make it into a handy sample of urine or blood, so which CAN we use?
Wednesday, 07 September 2016 13:22

Fighting Zika with Functional Fashion

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Function is often thought of as the tradeoff for high fashion, but who says you can’t have both? Fawn Jordan, 2016-2017 DC Fashion Incubator Designer in Residence, is seeking to unite the two to help protect women against potentially Zika-transmitting mosquitoes. Her recent collection combines two major mosquito avoidance methods: skin-covering clothing and mosquito netting.
Gruesome, ghastly, grisly. These are the words that popped into my head when I googled images of diabetic foot ulcers—one of the most common chronic wounds creating a silent and costly epidemic in healthcare.
When Candida albicans encounters stressful conditions, does it curl up and die? No! According to a paper just published in mBio, this crafty pathogen gets to work on its inventory of genes, slashing away until it finds a winning combination that can get it through the tough times. (I’ve written up other mBio papers about Candida here and here. I think I am gaining a grudging respect for this feisty fungus.)
Tuberculosis is no picnic, but taking the required medicines to treat the disease is a long slog: it takes six months, at least, to treat TB. To prevent patients from quitting treatment too soon, many doctors insist on “directly observed therapy”, where patients take their antibiotics under the watchful eye of a medical professional. However, they may also give their patients a weekly 2-day vacation from treatment. Taking a “drug holiday” from TB antibiotics not only offers patients a break from seeing their doctor every day, it can also boost the effectiveness of the drugs and increase patient adherence to…
A search goes faster with a tool to separate the wheat from the chaff. A pan can help you find gold flakes, and a metal detector can help you find a coin at the beach, but what tools can you use when you’re searching for a bacterium that can manufacture biofuels? In a study in mBio this week, researchers applied an old familiar microscopy tool in a new high-throughput method to help identify new strains of hydrocarbon-making microbes.
In the hunt for new organisms, sometimes you just get lucky. The authors of a paper in mBio this week found a virus that offered two discoveries for the price of one: it’s a novel organism that also reveals lessons in evolutionary ecology.
To get around host defenses, Salmonella enterica serovars that specialize in a single type of host are known to shuffle their genomic decks by recombining their chromosomes, rearrangements that result in inversions, translocations, duplications, or deletions of various sizes.
When a successful bacterium begins to outgrow its physical niche, things can get ugly. Colonies Paenibacillus dendritiformis, for instance, turns on its brothers and produces a toxic protein called Slf, which kills cells of encroaching sibling colonies. The bacterium senses when space gets tight, then deploys its toxic protein on nearby colonies so it won’t lose out in the struggle for space and nutrients.
I attended the ASM General Meeting in New Orleans this week and soaked up some science and some amazing New Orleans cuisine. I also loaded up on vendor tchotchkes. While browsing around the vendor booths I managed to acquire no fewer than FOUR bottles of hand sanitizer. After reading the latest in mBio, I'm glad I did.
Could a new test for prions put you back in the blood donors’ chair?
In mBio this week: a novel, hypervirulent strain of Chlamydia trachomatis is actually a combination of two well-known strains – one of them a harmless symbiont.
If you work in microbiology, you know the statistics: as many as 99% of bacterial species have yet to succumb to science’s best efforts to cultivate them. Even many of the bacteria we harbor within our bodies resist growing in culture, and if they can’t be grown in the laboratory we have limited opportunities to figure out what they do for us (or what they do to us). In mBio this week, a new approach to cultivating these reluctant microbes reads the metatranscriptome – the RNA a community of bacteria makes as a blueprint for making their proteins – for…
Without the benefit of sex to help them ensure their genetic legacy, bacteria employ horizontal Untitled-3 gene transfer to move genes from one cell to another. One way to get this done between cells in contact with one another is using integrative and conjugative elements (ICEs), DNA segments that normally reside within the host genome but are excised and form a circle before moving on to a recipient cell. Because they can move genes quickly within a community, ICEs contribute to the spread of genes involved in pathogenesis, symbiosis, metabolism, and antibiotic resistance.
Of the many things that have been said about gonorrhea, here’s one thing no one ever guessed: gonorrhea is a little bit human. A study published in mBio today reveals that the genomes of some strains of Neisseria gonorrhoeae carry a piece of the human long interspersed nuclear element (LINE) L1.
Wednesday, 02 February 2011 15:18

Metabolite bait-and-switch to fight tuberculosis

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There is a public health crisis brewing in medicine: in short, there are too many bad bugs and not Schematic enough drugs. Many pathogens have evolved resistance to our most potent antibiotics, and as of 2009, only fifteen antibacterial agents were under development, most of which are only in the early stages of the process. Think about that: of all the bacterial and fungal diseases out there, some of which have evolved resistance to even our second-line drugs, there are only 15 new drugs in the pipeline to treat them. Tuberculosis is particularly alarming when it comes to antibiotic resistance,…
Can you create an extremophile? The microbes living and thriving at the fringes of the biosphere manage to get by in spite of extreme temperatures, radiation levels, and pressures (did I miss any?) that most other life forms would choke on. But how easy would it be for an organism that prospers in the warm embrace of our digestive tract to make a change in lifestyle and become an extremophile? Pretty easy, as it turns out.
Reduce, reuse, recycle? Candida albicans is a reuser. No, it doesn’t use its old grocery bags over and over – it puts one set of proteins to work in two different jobs.
Salmonella enterica serovar Typhimurium is one of the major pathogens responsible for food poisoning in this country, and it has a thing for hydrogen gas. In mice, when you take away the proteins that allow S. Typhimurium to respire H2, the bacterium loses all virulence and no longer causes the gastrointestinal problems it is so well known for. But why is hydrogen so important?