The bacterium Micavibrio aeruginosavorus (yellow), leeching
on a Pseudomonas aeruginosa bacterium (purple).
What’s the news: If bacteria had blood, the predatory microbe Micavibrio aeruginosavorus would essentially be a vampire: it subsists by hunting down other bugs, attaching to them, and sucking their life out. For the first time, researchers have sequenced the genome of this strange microorganism, which was first identified decades ago in sewage water. The sequence will help better understand the unique bacterium, which has potential to be used as a “living antibiotic” due to its ability to attack drug-resistant biofilms and its apparent fondness for dining on pathogens.
Scientists have generally thought that superbugs are weaker than normal bacteria in drug-free environments because they expend more resources to maintain resistances, as seen by their slower cell-division rates. But researchers have now reported in the journal PLoS Genetics that some antibiotic-resistant superbugs can out-perform their normal cousins even when there are no drugs present. The results suggest that fighting these resilient bacteria will take more than just curbing antibiotic use.
What’s the News: Gonorrhea, known in earlier days as the clap, has generally been considered the training wheels of STDs: a young sailor on his first tour of duty would feel a slight burning while urination, get a big shot of penicillin in the infirmary, learn the error of his ways, and start carrying a condom in his wallet.
But after years of warning that drug resistance in STDs was on the way, scientists have now found a strain of the bacterium that stands up to the usual antibiotic treatments, sparking fears that the days of easily banished gonorrhea are over.
What’s the News: Adding sugar to certain antibiotics can boost their bacteria-battling ability, according to a study published today in Nature. In particular, sugar helps the drugs wipe out persisters, bacteria that evade antibiotics by essentially going dormant only to flare up again once the danger has passed. This technique could lead to the development of inexpensive, more effective treatments for bacterial infections.
What’s the News: Going undercover can require some sacrifices–burning off your fingerprints, for instance, a la Gattaca. It’s the same story with bacteria: they can slip below antibiotics’ radar without any mutations, but only using an elaborate system of self-sabotage. A new study reveals the workings of this biochemical disguise.
Image: Wikimedia Commons
New sea creatures, humongous stars, and cockroach antibiotics: Those are just a few reader favorites from this year in science. As 2010 comes to a close, we bring you a dozen of the most popular 80beats posts of the year.
For more great stories from the year in science, check out DISCOVER’s Top 100 Stories of the Year.
Cockroaches take advantage of our messy hospitality, skulking around in the cracks and holes of our houses and devouring the scraps we leave behind. Soon, though, maybe we’ll be the ones taking advantage of their fondness for filth.
The brains of these insects carry some serious antibiotics—strong enough to slaughter bacteria that have evolved resistance to the hospital antibiotics we use. The researchers presented their work at the Society for General Microbiology meeting this week in England, and say that while the finding is terrific, it’s no surprise given the roaches’ living circumstances:
“Some of these insects live in the filthiest places ever known to man,” says Naveed Khan, coauthor of the new study. “These insects crawl on dead tissue, in sewage, in drainage areas. We thought, ‘How do they cope with all the bacteria and parasites?’” [Science News]
Beer: Some people think it’s proof that God loves us and wants us to be happy. Others value it as a great source of antibiotics—of course, those people lived nearly 1,700 years ago.
For much of the last three decades, anthropologist George Armelagos has been trying to explain how mummies that date from an ancient kingdom in Nubia—the area south of Egypt that’s located in present-day Sudan—got so much of the antibiotic tetracycline in their bones. Since scientists didn’t synthesize antibiotics like that one until the 20th century (and these bones date back to between 350 to 550 A.D.), finding a buildup in ancient bones screams out “contamination.”
Armelagos and his colleagues longed to prove that it wasn’t, and in a study out in American Journal of Physical Anthropology, the team argues that the find is no fluke. Nubians got antibiotics into their systems by drinking beer, and lots of it, and from an early age.
How? Thanks to the help of a kind of bacteria called Streptomyces.
The antibiotics-resistant superbug that emerged in South Asia appears to have claimed its first life. According to doctors who treated a man in Belgium, he went to a hospital in Pakistan after a car accident, and there he picked up the bacterial infection. While the man died back in June, his doctors announced today that he carried the superbug.
This new health scare intensified this week after researchers published a study in The Lancet Infectious Diseases characterizing “a new antibiotic resistance mechanism” in the U.K., India, and Pakistan. How bad is this “mechanism?”
The problem isn’t a particular kind of bacteria. It’s a gene that encodes an enyzme called New Delhi metallo-lactamase-1 (NDM-1). Bacteria that carry it aren’t bothered by traditional antibiotics, or even the drugs known as carbapenems deployed against antibiotic-resistant microbes.
The NDM-1 gene is a special worry because it is found in plasmids — DNA structures that can easily be copied and then transferred promiscuously among different types of bacteria. These include Escherichia coli, the commonest cause of urinary tract infections, and Klebsiella pneumoniae, which causes lung and wound infections and is generated mainly in hospitals [AFP].
It’s no worse than what we had before: