Tag Archives: Antibiotics

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

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.

‘Virtually untreatable’ TB found

‘Virtually untreatable’ TB found:

TB presently causes about 1.7 million deaths a year worldwide, but researchers are worried about the emergence of strains that are resistant to drugs.

Drug resistance is caused by poor TB control, through taking the wrong types of drugs for the incorrect duration.

Multi-drug resistant TB (MDR TB), which describes strains of TB that are resistant to at least two of the main first-line TB drugs, is already a growing concern.

Globally, the WHO estimates there are about 425,000 cases of MDR TB a year, mostly occurring in the former Soviet Union, China and India.

How do antibiotics kill bacteria?

How do antibiotics kill bacterial cells but not human cells? (pointy haired bosses (phb) at Scientific American broke the link so I removed it – see links in comments below that are not broken by phb behavior)

Most bacteria produce a cell wall that is composed partly of a macromolecule called peptidoglycan, itself made up of amino sugars and short peptides. Human cells do not make or need peptidoglycan. Penicillin, one of the first antibiotics to be used widely, prevents the final cross-linking step, or transpeptidation, in assembly of this macromolecule. The result is a very fragile cell wall that bursts, killing the bacterium.

Read more blog posts on antibiotics and on health care.

Evolution of Antibiotic Resistance

Inhibition of Mutation and Combating the Evolution of Antibiotic Resistance from the Public Library of Science Biology Journal:

The emergence of drug-resistant bacteria poses a serious threat to human health. In the case of several antibiotics, including those of the quinolone and rifamycin classes, bacteria rapidly acquire resistance through mutation of chromosomal genes during therapy. In this work, we show that preventing induction of the SOS response by interfering with the activity of the protease LexA renders pathogenic Escherichia coli unable to evolve resistance in vivo to ciprofloxacin or rifampicin, important quinolone and rifamycin antibiotics. We show in vitro that LexA cleavage is induced during RecBC-mediated repair of ciprofloxacin-mediated DNA damage and that this results in the derepression of the SOS-regulated polymerases Pol II, Pol IV and Pol V, which collaborate to induce resistance-conferring mutations. Our findings indicate that the inhibition of mutation could serve as a novel therapeutic strategy to combat the evolution of antibiotic resistance.

Soil Could Shed Light on Antibiotic Resistance

Soil Could Shed Light on Antibiotic Resistance, Science Friday podcast (7 minutes) from NPR. The podcast is an interview with Gerry Wright, McMaster University, Canada.

“New research points to drug resistance in soil-dwelling bacteria. Scientists say studying bacteria in the soil can help in understanding how the bacteria in humans develop resistance.”

Posts relating to antibiotics
Overuse of anitbiotics articles
Curious Cat McMaster University Alumni Connections