New antibiotic cures disease by disarming pathogens, not killing them

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    Oct 04, 2012 2:11 PM GMT
    This couldn't come too soon...

    A new type of antibiotic can effectively treat an antibiotic-resistant infection by disarming instead of killing the bacteria that cause it. Researchers report their findings in the October 2 issue of mBio, the online open-access journal of the American Society for Microbiology.

    "Traditionally, people have tried to find antibiotics that rapidly kill bacteria. But we found a new class of antibiotics which has no ability to kill Acinetobacter that can still protect, not by killing the bug, but by completely preventing it from turning on host inflammation," says Brad Spellberg of the UCLA Medical Center and David Geffen School of Medicine, a researcher on the study.

    New drugs are badly needed for treating infections with the bacterium Acinetobacter baumannii, a pathogen that most often strikes hospital patients and immune- compromised individuals through open wounds, breathing tubes, or catheters. The bacterium can cause potentially lethal bloodstream infections. Strains of A. baumannii have acquired resistance to a wide range of antibiotics, and some are resistant to every FDA-approved antibiotic, making them untreatable.

    Spelling and his colleagues found that in laboratory mice it was possible to mitigate the potentially lethal effects of the bacterium by blocking one of its toxic products rather than killing it.

    "We found that strains that caused the rapidly lethal infections shed lipopolysaccharide [also called LPS or endotoxin] while growing. The more endotoxin shed, the more virulent the strain was," says Spellberg. This pinpointed a new therapy target for the researchers: the endotoxin these bacteria shed in the body.
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    Oct 04, 2012 2:55 PM GMT
    riddler78 saidThis couldn't come too soon...

    Uh, do you know something that we don't know?......(feeling nervous) lol

    Does that mean that the infected person becomes a carrier of the disease? If someone else gets infected with that persons' disease will they inherit the disease as well as the cure?
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    Oct 07, 2012 12:56 PM GMT
    Traditionally, drugs that inhibit the ability of a bacterium to divide were termed "bacteriostatic". They've been around a long time, and are often used in cases where killing a bacteria is harmful to the host (some bacteria release endotoxins upon death, which can be deadly at high concentrations). As a result, we use bacteriostatic drugs to control the number of bacteria, and then allow the host's immune system to clean up the mess (for otherwise healthy individuals).

    A problem arises when the host's immune system is not strong enough to fight off an infection, or when a bacteria is resistant to antibiotics. The first may occur in immune-compromised patients (AIDS for instance), and the other occurs from a form of natural selection that our disinfectant-happy society promotes. I see this new mode of treatment - if it can be called that - being used in specific instances, where "normal" treatments fall short. However, as the encounters with super-bacteria increase, it may become more of a common practice.

    In response to the above comment:

    In theory, if you were to contract a bacterium from an individual receiving a medication that blocked its ability to produce endotoxin and hindered the inflammatory response, you would most likely not be protected from the bacteria. If there was a lingering concentration of "drug" inside the bacterium when you contracted it, the effects of the medication may remain for a short period of time, but eventually you would have to begin taking the medication yourself.

    The only exception that I can think of to this, is if the medication was a type of therapy that altered the bacterium's genome, permanently inhibiting its ability to produce endotoxin (which may kill the bacteria, because endotoxins are part of the LPS, which has other functions). It would have to alter its genome to prevent antigens from arising on its membrane as well...which would be quite the feat.