Category Archives: Antibiotics

Superbugs – Deadly Bacteria Take Hold

Superbugs by Jerome Groopman, New Yorker:

“My basic premise,” Wetherbee said, “is that you take a capable microÃ¶rganism like Klebsiella and you put it through the gruelling test of being exposed to a broad spectrum of antibiotics and it will eventually defeat your efforts, as this one did.” Although Tisch Hospital has not had another outbreak, the bacteria appeared soon after at several hospitals in Brooklyn and one in Queens. When I spoke to infectious-disease experts this spring, I was told that the resistant Klebsiella had also appeared at Mt. Sinai Medical Center, in Manhattan, and in hospitals in New Jersey, Pennsylvania, Cleveland, and St. Louis.
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Unlike resistant forms of Klebsiella and other gram-negative bacteria, however, MRSA can be treated. “There are about a dozen new antibiotics coming on the market in the next couple of years,” Moellering noted. “But there are no good drugs coming along for these gram-negatives.” Klebsiella and similarly classified bacteria, including Acinetobacter, Enterobacter, and Pseudomonas, have an extra cellular envelope that MRSA lacks, and that hampers the entry of large molecules like antibiotic drugs. “The Klebsiella that caused particular trouble in New York are spreading out,” Moellering told me. “They have very high mortality rates. They are sort of the doomsday-scenario bugs.”

Great article. Related: Bacteria Survive On All Antibiotic Diet – Bacteria Can Transfer Genes to Other Bacteria – New Yorker on CERN’s Large Hadron Collider – posts on health related topics

Alligator Blood Provides Strong Resistance to Bacteria and Viruses

Gator Blood May Be New Source of Antibiotics

The study authors, from McNeese State University and Louisiana State University, said their research is the first to take an in-depth look at alligator blood’s prospects as an antibiotic source. According to the researchers, alligators can automatically fight germs such as bacteria and viruses without having been exposed to them before launching a defense.

For the study, the researchers extracted proteins known as peptides from white cells in alligator blood. As in humans, white cells are part of the alligator’s immune system. The researchers then exposed various types of bacteria to the protein extracts and watched to see what happened.

In laboratory tests, tiny amounts of these protein extracts killed a so-called “superbug” called methicillin-resistant Staphylococcus aureus, or MRSA. The bacteria has made headlines in recent years because of its killing power in hospitals and its spread among athletes and others outside of hospitals.

The extracts also killed six of eight strains of a fungus known as Candida albicans, which causes a condition known as thrush, and other diseases that can kill people with weakened immune systems.

E. Coli Individuality

Expressing Our Individuality, the Way E. Coli Do by Carl Zimmer

A good counterexample is E. coli, a species of bacteria that lives harmlessly in every person’s gut by the billions. A typical E. coli contains about 4,000 genes (we have about 20,000). Feeding on sugar, the microbe grows till it is ready to split in two. It makes two copies of its genome, almost always managing to produce perfect copies of the original. The single microbe splits in two, and each new E. coli receives one of the identical genomes. These two bacteria are, in other words, clones.
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A colony of genetically identical E. coli is, in fact, a mob of individuals. Under identical conditions, they will behave in different ways. They have fingerprints of their own.
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E. coli appears to follow a universal rule. Other microbes exploit noise, as do flies, worms and humans. Some of the light-sensitive cells in our eyes are tuned to green light, and others to red. The choice is a matter of chance. One protein may randomly switch on the green gene or the red gene, but not both.

In our noses, nerve cells can choose among hundreds of different kinds of odor receptors. Each cell picks only one, and evidence suggests that the choice is controlled by the unpredictable bursts of proteins within each neuron. It’s far more economical to let noise make the decision than to make proteins that can control hundreds of individual odor receptor genes.

Identical genes can also behave differently in our cells because some of our DNA is capped by carbon and hydrogen atoms called methyl groups. Methyl groups can control whether genes make proteins or remain silent. In humans (as well as in other organisms like E. coli), methyl groups sometimes fall off of DNA or become attached to new spots. Pure chance may be responsible for changing some methyl groups; nutrients and toxins may change others.

Clay Versus MRSA Superbug

“Healing clays” hold promise in fight against MRSA superbug infections and disease

Scientists from Arizona State University report that minerals from clay promise could provide inexpensive, highly-effective antimicrobials to fight methicillin-resistant Staphylococcus aureus (MRSA) infections that are moving out of health care settings and into the community.
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Unlike conventional antibiotics routinely administered by injection or pills, the so-called “healing clays” could be applied as rub-on creams or ointments to keep MRSA infections from spreading
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In their latest study, funded by the National Institutes of Health, Williams, Haydel and their colleagues collected more than 20 different clay samples from around the world to investigate their antibacterial activities… The researchers identified at least two clays from the United States that kill or significantly reduce the growth of these bacteria

Also listen to a podcast with the researchers, Lynda Williams and Shelly Haydel, that provides much more detail. The Science Studio podcasts from Arizona State University provides great science podcasts.

Bacteria Survive On All Antibiotic Diet

Bacteria Survive on All-Antibiotic Diet

The scientists wanted to make sure they had a good control—a group of bacteria that didn’t grow at all—so they bathed some of the bacteria in antibiotics. But there was a problem: The bacteria didn’t just survive in the antibiotics, they consumed them. The researchers then gathered soil from 11 sites with varying degrees of exposure to human-made antibiotics (from manure-filled cornfields to an immaculate forest) and found that every site contained bacteria, including relatives of Shigella and the notorious E. coli that could survive solely on antibiotics. And these weren’t just piddling doses—the bacteria could tolerate levels of antibiotics that were up to 100 times higher than would be given to a patient, and 50 times higher than what would qualify a bacterium as resistant.

Bacteria Can Transfer Genes to Other Bacteria

From page 115 of Good Gems, Bad Germs:

Microbiologists of the 1950’s did not appreciate the stunning extent to which bacteria swap genes… In 1959 Japanese hospitals experience outbreaks of multidrug-resistant bacterial dysentery. The shigella bacteria, which caused the outbreaks, were shrugging off four different classes of previously effective antibiotics: sulfonamides, streptomycins, chloramphenicols, and tetracyclines… In fact, the Japanese researches found it quite easy to transfer multidrug resistance from E. coli to shingella and back again simply by mixing resistant and susceptible strains together in a test tube.

Some Bacteria Might Fight Cancer

Cancer and the bacterial connection

today, some scientists think Coley had it right: Germs can teach our bodies how to fight back against tumors. Dr. John Timmerman, a cancer immunotherapy expert at UCLA’s Jonsson Cancer Center, says this revolution has produced “the most exciting sets of compounds in cancer immunolog
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The studies also imply that our cleaner, infection-free lifestyles may be contributing to the rise in certain cancers over the last 50 years, scientists say, because they make the immune system weaker or less mature. Germs cause disease but may also fortify the body, a notion summed up in a 2006 report by a team of Canadian researchers as “whatever does not kill me makes me stronger.”
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Other groups have been experimenting with injections of other types of heat-killed bacteria, including Myobacterium vaccae, a tuberculosis relative. In two studies in January’s European Journal of Cancer, researchers report that these bacteria may help fight certain lung and renal cancers.

The rich interplay of complex systems are often very difficult to grasp simply. I discusses this concept in the post on the excellent book, Parasite Rex.

Fight to curtail antibiotics in animal feed

Consumer advocates have been campaigning for years to curb the use of antibiotics in agriculture, citing studies that show that 70 percent of all U.S. antibiotics are administered in low doses – not to treat disease, but to promote the growth of pigs, sheep, chicken and cattle.
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But as early as 1963, British researchers tied the emergence of drug-resistant strains of salmonella in humans to antibiotics fed to cattle.

Bacteria Race Ahead of Drugs

Bacteria race ahead of drugs

Dr. Jeff Brooks has been director of the UCSF lab for 29 years, and has watched with a mixture of fascination and dread how bacteria once tamed by antibiotics evolve rapidly into forms that practically no drug can treat.
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“We are on the verge of losing control of the situation, particularly in the hospitals,” said Dr. Chip Chambers, chief of infectious disease at San Francisco General Hospital. The reasons for increasing drug resistance are well known:
– Overuse of antibiotics, which speeds the natural evolution of bacteria, promoting new mutant strains resistant to those drugs.
– Careless prescribing of antibiotics that aren’t effective for the malady in question, such as a viral infection.
– Patient demand for antibiotics when they aren’t needed.
– Heavy use of antibiotics in poultry and livestock feed, which can breed resistance to similar drugs for people.
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Terry Hazen, senior scientist at Lawrence Berkeley National Laboratory and director of its ecology program, is not at all surprised by the tenacity of our bacterial foes. “We are talking about 3.5 billion years of evolution,” he said. “They are the dominant life on Earth.”

Bacteria have invaded virtually every ecological niche on the planet. Human explorers of extreme environments such as deep wells and mines are still finding new bacterial species. “As you go deeper into the subsurface, thousands and thousands of feet, you find bacteria that have been isolated for millions of years – and you find multiple antibiotic resistance,” Hazen said.

In his view, when bacteria develop resistance to modern antibiotics, they are merely rolling out old tricks they mastered eons ago in their struggle to live in harsh environments in competition with similarly resilient species.

We have written often about the misuse of anti-biotics. This is a serious problem. And it is sad to see yet another example of well know scientific facts being ignored and by so doing threatening the healthy lives of others. i just finished a great book on bacteria and human health – Good Germs, Bad Germs.

New Drug Targets May Fight Tuberculosis in Novel Way

New Drug Targets May Fight Tuberculosis and Other Bacterial Infections in Novel Way

“We have developed the first inhibitor of a key small molecule from Mycobacterium tuberculosis and Mycobacterium leprae (which causes leprosy) utilized to subvert human host’s defenses and damage and invade human host’s cells during infection,” explains study senior author Dr. Luis Quadri, Associate Professor of Microbiology and Immunology at Weill Cornell.
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“We are moving beyond antimicrobials such as antibiotics, which kill the bacterium directly, to anti-infectives, that may have no effect against the pathogen in the test tube but which do compromise its ability to infect and spread in the host,” he explains. “We believe that the expansion of the drug armamentarium to include such anti-infective drugs could help the fight against multi-drug resistant infection that has become such a challenge today.”
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“I believe that drugs targeting virulence factors are just one component of the paradigm shift in the antimicrobial drug discovery for the 21st century—one that will offer patients more options in the fight against truly global killers,” he says.