Category Archives: Antibiotics

Antibacterial Chemical Disrupts Hormone Activities

Antibacterial Chemical Disrupts Hormone Activities:

A new UC Davis study shows that a common antibacterial chemical added to bath soaps can alter hormonal activity in rats and in human cells in the laboratory — and does so by a previously unreported mechanism.

The findings come as an increasing number of studies — of both lab animals and humans — are revealing that some synthetic chemicals in household products can cause health problems by interfering with normal hormone action. Called endocrine disruptors, or endocrine disrupting substances (EDS), such chemicals have been linked in animal studies to a variety of problems, including cancer, reproductive failure and developmental anomalies.

The researchers found two key effects: In human cells in the laboratory, triclocarban increased gene expression that is normally regulated by testosterone. And when male rats were fed triclocarban, testosterone-dependent organs such as the prostate gland grew abnormally large. Also, the authors said their discovery that triclocarban increased hormone effects was new. All previous studies of endocrine disruptors had found that they generally act by blocking or decreasing hormone effects.

In their disclosure statement, the authors report that six of them have taken steps to patent their findings through the University of California.

Research paper Triclocarban enhances testosterone action: A new type of endocrine disruptor?.

People Have More Bacterial Cells than Human Cells

Humans Carry More Bacterial Cells than Human Ones

All the bacteria living inside you would fill a half-gallon jug; there are 10 times more bacterial cells in your body than human cells
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The infestation begins at birth: Babies ingest mouthfuls of bacteria during birthing and pick up plenty more from their mother’s skin and milk—during breast-feeding, the mammary glands become colonized with bacteria. “Our interaction with our mother is the biggest burst of microbes that we get,”
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there are estimated to be more than 500 species living at any one time in an adult intestine, the majority belong to two phyla, the Firmicutes (which include Streptococcus, Clostridium and Staphylococcus), and the Bacteroidetes (which include Flavobacterium).
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probiotics – dietary supplements containing potentially beneficial microbes – have been shown to boost immunity. Not only do gut bacteria “help protect against other disease-causing bacteria that might come from your food and water,” Huffnagle says, “they truly represent another arm of the immune system.”
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But the bacterial body has made another contribution to our humanity – genes. Soon after the Human Genome Project published its preliminary results in 2001, a group of scientists announced that a handful of human genes – the consensus today is around 40 – appear to be bacterial in origin.

How cool is science? Very, I think 🙂

Fighting Tuberculosis

Signaling an End to TB by Kathleen M. Wong

Once routinely treated with cheap antibiotics, TB is poised to make a terrifying comeback. More and more, doctors in developing nations are finding patients infected with strains of TB invulnerable to all but a handful of extremely expensive, exotic drugs. Worldwide, TB already infects one in every three people and sickens one in ten. Without new methods to stop the spread of drug-resistant strains, the cost of treating this ancient human pathogen could bankrupt even the most prosperous economies.
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TB could, in theory, develop resistance to this new class of drugs, too. But Alber thinks he can skew the odds to favor humans. Identifying a drug capable of knocking out several TB enzymes at once could make it next to impossible for the bacterium to evolve resistance on multiple fronts.

Though TB is a daunting foe, Alber remains confident about the prospects of beating the disease. “As a bacterium, it should be easier to treat than HIV or malaria. Those kinds of diseases-caused by viruses and protozoans-we generally don’t know how to cure,” Alber says. “From a scientific perspective, TB is a simpler problem.”

Good luck, it may be easier but it still isn’t easy. Related: Tuberculosis Risk – ‘Virtually untreatable’ TB – Extensively Drug-resistant Tuberculosis (XDR TB) – TB Pandemic Threat

Disrupting Bacteria Communication

Princeton scientists break cholera’s lines of communication

A team of Princeton scientists has discovered a key mechanism in how bacteria communicate with each other, a pivotal breakthrough that could lead to treatments for cholera and other bacterial diseases.

The mechanism is a chemical that cholera bacteria use for transmitting messages to each other, known as CAI-1, and has been isolated in the lab of molecular biologist Bonnie Bassler. Her team has shown that the chemical also can be used to disrupt the communication that exists among the bacteria, potentially halting the disease’s progress. The discovery could lead to an entirely new class of antibiotics.
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Higgins isolated the CAI-1 chemical, which occurs naturally in cholera. Then, Megan Pomianek, a graduate student in the laboratory of Martin Semmelhack, a professor of chemistry at Princeton, determined how to make the molecule in the laboratory. Higgins used this chemical essentially to control cholera’s behavior in lab tests.

The team found that when CAI-1 is absent, cholera bacteria act as pathogens. But when the bacteria detect enough of this chemical, they stop making biofilms and releasing toxins, perceiving that it is time to leave the body instead. “Our findings demonstrate that if you supply CAI-1 to cholera, you can flip their switches to stop the attack,” Higgins said.

Chemist Helen Blackwell of the University of Wisconsin-Madison praised the study, calling it a breakthrough for quorum sensing research, and possibly for medical science.

MRSA Blows Up Defender Cells

Superbug succeeds by blowing up defender cells, scientists learn

While only 14 percent of serious MRSA infections are the community associated kind, they have drawn attention in recent months with a spate of reports in schools, including the death of a 17-year-old Virginia high school student. Both hospital-associated and community-associated MRSA contained genes for the peptides. But their production was much higher in the CA-MRSA, the researchers said.
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The compounds first cause inflammation, drawing the immune cells to the site of the infection, and then destroy those cells. The research was conducted in mice and with human blood in laboratory tests. Within five minutes of exposure to the peptides from CA-MRSA, human neutrophils showed flattening and signs of damage to their membrane, researchers said. After 60 minutes, many cells had disintegrated completely.

“This elegant work helps reveal the complex strategy that S. aureus has developed to evade our normal immune defenses,” Dr. Anthony S. Fauci, NIAID director, said in a statement. “Understanding what makes the infections caused by these new strains so severe and developing new drugs to treat them are urgent public health priorities.”

Killing Germs May Be Hazardous to Your Health

Caution: Killing Germs May Be Hazardous to Your Health

Relman is a leader in rethinking our relationship to bacteria, which for most of the last century was dominated by the paradigm of Total Warfare. “It’s awful the way we treat our microbes,” he says, not intending a joke; “people still think the only good microbe is a dead one.” We try to kill them off with antibiotics and hand sanitizers. But bacteria never surrender; if there were one salmonella left in the world, doubling every 30 minutes, it would take less than a week to give everyone alive diarrhea. In the early years of antibiotics, doctors dreamed of eliminating infectious disease. Instead, a new paper in The Journal of the American Medical Association reports on the prevalence of Methicillinresistant Staphylococcus aureus (MRSA), which was responsible for almost 19,000 deaths in the United States in 2005—about twice as many as previously thought, and more than AIDS. Elizabeth Bancroft, a leading epidemiologist, called this finding “astounding.”

As antibiotics lose their effectiveness, researchers are returning to an idea that dates back to Pasteur, that the body’s natural microbial flora aren’t just an incidental fact of our biology, but crucial components of our health, intimate companions on an evolutionary journey that began millions of years ago.

Blocking Bacteria From Passing Genes to Other Bacteria

Scientists are working on many fronts to keep deadly bacteria in check

Bacteria that cause cholera and bubonic plague turn from harmless to deadly with the flip of a genetic switch. Jam the switch and you might prevent infection, said Vladimir Svetlov, a microbiology research associate at Ohio State University and one of a group of scientists who defined the structure of a protein that appears to be the key. The discovery is one of many this year to identify structures and chemicals crucial to disease. All of this work could lead to new medicines.

At the same time, germs we once fought off with antibiotics are fighting back, forcing governments and health organizations worldwide to spend billions of dollars to find new remedies.
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Redinbo is part of a team that recently discovered that two osteoporosis drugs block a key site on E. coli bacteria, preventing it from passing antibiotic resistance genes to other E. coli.

By their nature, bacteria exchange pieces of their DNA with neighboring bacteria, leading to new forms that are virulent or resistant — or both. “This is not minor evolution,” said Irina Artsimovitch, associate professor of microbiology at Ohio State. “This is a huge genome exchange.”

Very cool stuff. Related: Antibiotic resistance: How do antibiotics kill bacteria? – Disrupting the Replication of Bacteria – Antibiotics Too Often Prescribed for Sinus Woes – Attacking Bacterial Walls

Antibacterial Soaps are Bad

Consumer Antibacterial Soaps: Effective or Just Risky? by Allison E. Aiello, Elaine L. Larson, and Stuart B. Levy

Methods. The PubMed database was searched for English-language articles, using relevant keyword combinations for articles published between 1980 and 2006. Twenty-seven studies were eventually identified as being relevant to the review.

Results. Soaps containing triclosan within the range of concentrations commonly used in the community setting (0.1%ndash0.45% wt/vol) were no more effective than plain soap at preventing infectious illness symptoms and reducing bacterial levels on the hands. Several laboratory studies demonstrated evidence of triclosan-adapted cross-resistance to antibiotics among different species of bacteria.

Conclusions. The lack of an additional health benefit associated with the use of triclosan-containing consumer soaps over regular soap, coupled with laboratory data demonstrating a potential risk of selecting for drug resistance, warrants further evaluation by governmental regulators regarding antibacterial product claims and advertising. Further studies of this issue are encouraged.

The article is not open access unfortunately but this summary was actually pretty good. Via Antibacterial soap: Just Risky

Raised Without Antibiotics

Tyson is going to start selling chicken Raised Without Antibiotics. The overuse of antibiotics is a huge problem and the overuse in the raising of livestock is a huge problem.

“While we have great confidence in the quality of our traditional chicken, we’re also committed to providing mainstream consumers with the kind of products they want,” said Richard L. Bond, president and CEO of Tyson Foods. “According to our research, 91% of consumers agree it’s important to have fresh chicken produced and labeled ‘raised without antibiotics’,” Bond said.

Tyson started selling 100% All Naturalâ„¢, Raised Without Antibiotics chicken this week. The product is being distributed nationwide in newly-designed packaging highlighting that the chicken is raised without antibiotics and contains no artificial ingredients.

While it is nice they will start selling a portion of chicken raised without using antibiotics and endangering the health of the community by helping evolve super-resistant bugs this is really a pretty small step I would guess. The risk is not even mainly to the person eating the food pumped full of antibiotics it is to everyone when drug resistant bacteria are evolved through the overuse of antibiotics. Also, 100% All Natural is trademarked? Give me a break.

Nationwide Survey Reveals Most Americans are Unaware They Consume Beef and Poultry Raised on Antibiotics (2003)

“Antibiotic medicines are losing effectiveness on humans due to their increased use in animal feed,” said Margaret Mellon, Ph.D, JD, director of the food and environment program for the Union of Concerned Scientists. “Animals raised in natural environments rarely require the use of antibiotics. Americans who choose meat produced this way are making conscious decisions to ensure that antibiotics will still be working when they or their family need them.” The Union of Concerned Scientists estimates that 70 percent of all antibiotics in the United States are now fed to animals raised for human consumption in order to hasten the animals’ growth or prevent illness amid crowded, unsanitary conditions on factory farms.

Abuse of Antibiotics at Factory Farms Threatens the Effectiveness of Drugs Used to Treat Disease in Humans:

According to the Center for Disease Control, more than one-third of the salmonella poisoning cases in 1997 were found to be resistant to five antibiotics. Drug resistance in campylobacter bacteria, the most commonly known cause of bacterial food-borne illness in the United States, increased from zero in 1991 to 14 percent in 1998.
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The European Union, on the recommendation of the World Health Organization, has banned the use of antibiotics to promote the growth of livestock animals when those drugs are also used to treat people. The Center for Disease Control has agreed with this position, but the U.S. government has failed to reduce the threat that ineffective antibiotics pose to human health. (Lieberman, et.al., 1999)

To reduce serious health threats, the Food and Drug Administration should ban the use of antibiotics to promote livestock growth when those antibiotics are used to treat humans.

Tracking the Ecosystem Within Us

Gut Check: Tracking the Ecosystem Within Us

For more than 100 years, scientists have known that humans carry a rich ecosystem within their intestines. An astonishing number and variety of microbes, including as many as 400 species of bacteria, help humans digest food, mitigate disease, regulate fat storage, and even promote the formation of blood vessels. By applying sophisticated genetic analysis to samples of a year’s worth baby poop, Howard Hughes Medical Institute researchers have now developed a detailed picture of how these bacteria come and go in the intestinal tract during a child’s first year of life.
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Before birth, the human intestinal tract is sterile, but babies immediately begin to acquire the microbial denizens of the gut from their environment — the birth canal, mothers’ breast, and even the touch of a sibling or parent. Within days, a thriving microbial community is established and by adulthood, the human body typically has as many as ten times more microbial cells than human cells.
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The results, said Palmer, were striking: the group found that the intestinal microbial communities varied widely from baby to baby – both in terms of which microbes were present and in how that composition changed over time. That finding, she said, is important because it helps broaden the definition of healthy microbial colonization in a baby.

Another intriguing observation, Palmer noted, was a tendency for sudden shifts in the composition of the infants’ intestinal microbial communities over time as different species of bacteria ebbed and flowed.

I find this area and this study fascinating. I’m not exactly sure why this study and the incredibly significant positive bacteria for human life news doesn’t get more notice. Oh well I guess there are not cool pictures of robots or scary stories of potential threats to those reading which makes the news less interesting to some. Still I find this stuff amazing: Energy Efficiency of Digestion – Beneficial Bacteria – Skin Bacteria – Hacking Your Body’s Bacteria for Better Health – Where Bacteria Get Their Genes