Monday, February 20, 2012

Increasing Number of Antibiotic Resistant Diseases

Britain is facing a "massive" rise in antibiotic-resistant blood poisoning caused by the bacterium E.coli – bringing closer the spectre of diseases that are impossible to treat.

Experts say the growth of antibiotic resistance now poses as great a threat to global health as the emergence of new diseases such as Aids and pandemic flu.
Other diseases are increasingly becoming drug resistant as well, such as gonorrhea (see also here), and tuberculosis. This article notes:
Dr. Trevor Van Schooneveld, an assistant professor of infectious disease at UNMC, said American scientists began seeing highly resistant bacteria strains in large quantities in the 1990s. But Alexander Fleming, who discovered penicillin, warned some 65 years ago that bacteria would become resistant to antibiotics, Van Schooneveld said.

Antibiotics still work well against some illnesses, such as strep throat. But bacteria that cause gonorrhea, skin infections such as MRSA and some urinary tract infections are growing tougher to defeat with antibiotics.

Creighton’s Wilson said drug-resistant bacteria are of even greater concern because there aren’t many new antibiotics being created now.
In addition to the article previously cited, this article also discusses the issues with drug-resistant TB:
On the heels of the news of totally drug-resistant (TDR) TB being identified in India — and disavowed, unfortunately, by the Indian government — the World Health Organization has released an update on the background situation of drug-resistant TB around the world.

The news is not good. Drug-resistant TB is at the highest rates ever recorded.
* * *
By agreed-up international definitions, MDR (multi-drug resistant) TB is unaffected by the first-line drugs, and XDR (extensively drug-resistant) TB is not susceptible to any of the first-line drugs and some of the second-line ones also. In addition, doctors who have seen TDR cases (which was originally dubbed XXDR for “extremely” drug-resistant) say those strains are resistant to every drug they have available locally — but the WHO has objected to that terminology, pointing out that “everything available locally” is not necessarily the same thing as “every drug available anywhere.”

This new WHO report is primarily concerned with MDR and XDR. It says that MDR-TB has now been identified in 80 countries; XDR TB has been found in 77. The meat of the report, though, is in these numbers; overall:
19.8 percent of MDR patients were previously treated for TB.
3.4 percent were never treated for TB before.
9.4 percent of all resistant cases are XDR.

Here’s what is going on there. MDR in a previously treated patient represents a failure of treatment: They did not take their drugs, were not able to get drugs, or got counterfeit drugs; their TB strain was not knocked out, but persisted and strengthened. But MDR in a first-time patient represents transmission of MDR-TB from someone who developed it. Those patients never get a chance to try the easier drugs. And XDR in any patient, whether newly acquired or bred via poor treatment, is an emergency.

Within the report, some of the numbers are staggering. The proportion of previously treated cases that become MDR is 51 percent in Belarus, 60 percent in Lithuania, 65 percent in Moldova. In China, 26 percent of previously treated TB cases are now MDR. In Estonia, 19 percent of all MDR cases are now XDR. Meanwhile, India and Russia, two of the biggest contributors to resistant TB because of their size and the state of their healthcare systems, report resistant cases only on a local level, not nationally. And most of Africa lacks the infrastructure to measure resistant TB at all.
There is some hope, however. As this article reports:
A Chilean avocado may contain the secret to fighting aggressive, antibiotic-resistant infections in hospitals all over the world.

A natural substance found in the Chilean rainforest fruit blocks yellow staphylococci bacteria's ability to reject antibiotics.

These specific bacteria are the most common cause of infection in wounds from an operation.

They develop a resistance particularly quickly - strains that do not respond to treatment have already been found in the USA and Greece.

PhD student Jes Gitz Holler, from the University of Copenhagen, worked with the Mapuche people in Chile to make the discovery.

He said: 'I have discovered a natural substance in a Chilean avocado plant that is active in combination treatment with traditional antibiotics.

'Resistant bacteria have an efflux pump in their bacterial membrane that efficiently pumps out antibiotics as soon as they have gained access.

'I have identified a natural substance that inhibits the pumping action, so that the bacteria's defence mechanisms are broken down and the antibiotic treatment allowed to work,' explains Jes Gitz Holler.

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