Category: Antibiotics (page 3 of 6)

more on the antibiotic resistance crisis

bacteriaThe New York Times editoriaizes on the CDC study that found 23,000 people a year die each year due to infections from drug resistant bacteria:

The new report, for the first time, puts 17 drug-resistant bacteria and a dangerous fungus into three categories based on how big a threat they pose. Three were deemed “urgent threats,” including a bacterium, known as CRE, that is resistant to most drugs and kills a high percentage of people who become infected with it. Though it is rare, causing 600 deaths a year, it has been identified in health facilities in 44 states. Further spread of the germ or transfer of its resistance genes to other germs could lead to a “nightmare scenario,” the agency said. Twelve drug-resistant strains, including such common germs as salmonella, tuberculosis and MRSA, were classified as “serious threats.”

Scientific American also covers a paper published in JAMA Internal Medicine that links pig manure fertilizer to MRSA (methicillin-resistant staphylococcus aureus infections in humans. From Scientific American:

The team analyzed cases of two different types of MRSA — community-associated MRSA (CA-MRSA), which affected 1,539 patients, and health-care-associated MRSA (HA-MRSA), which affected 1,335 patients. (The two categories refer to where patients acquire the infection as well as the bacteria’s genetic lineages, but the distinction has grown fuzzier as more patients bring MRSA in and out of the hospital.) Then the researchers examined whether infected people lived near pig farms or agricultural land where pig manure was spread. They found that people who had the highest exposure to manure — calculated on the basis of how close they lived to farms, how large the farms were and how much manure was used — were 38% more likely to get CA-MRSA and 30% more likely to get HA-MRSA.

Expect to hear about this more and more.

23,000 people a year die from superbugs

Staph aureus

Drug resistan staph aureus

That’s the result of the latest study from the CDC which you can read here. At least 2 million people annually are infected by resistant bacteria. Popular Science has more on the results of the study and on resistant bacteria in general.

fungal sex

penicillium

Penicillium chrysogenum bacteria

Penicillium bacteria were thought to reproduce asexually. A new study shows that a certain strain of the bacteria still has the genes required to carry out sexual reproduction and that these genes are linked to the production of penicillin. From SciAm:

Paul Dyer, a fungal biologist at the University of Nottingham in England, suspected that P. chrysogenum would reproduce sexually if given the right encouragement. A complete sequencing of the fungi’s genome revealed that P. chyrosogenum still carried the genes needed for mating. “That told us that there was perhaps sexual compatibility there,” he says. So Dyer and researchers at several other European institutions tried to find the ideal conditions that would encourage P.chrysogenum to have sex.

First, Dyer and his colleagues paired strains with compatible mating genes (P. chyrosogenum has two different sexes) and grew them with different food and light conditions. The winning combination was an oatmeal-base supplemented with a vitamin called biotin. After five weeks in the dark, the fungi produced special structures called cleistothecia and ascospores, which only occur after sexualreproduction. Genetic analysis confirmed that genes had been sexually recombined. “We’ve now revealed its secret sexual side,” Dyer says.

Furthermore, the researchers discovered that the genes that regulate the fungi’s sexual ability also control the amount of penicillin it produces; the fungi that are having sex make more penicillin. The team published their findings online in January in Proceedings of the National Academy of Sciences. “I’ve believed for a long time that these guys were having sex but they were just doing it in secret,” says Joan W. Bennett, a professor of plant biology and pathology at Rutgers University, who was not involved in the work.

Researchers are hoping that this leads to more efficient penicillin production or maybe even the discovery of new antibiotics.

//groutaissou.net/4/4535925