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The problem is getting worse while there are few new drugs in the pipeline, studies indicate
The emergence of bacteria that have resistance to antibiotics has remained to present a key public health issue, according to scientists getting together last October at one of the biggest infectious diseases conferences in the world.
Foremost among the issues are antibiotic-resistant gram-negative bacteria as well as bacteria that seem to be attacking people who are younger and otherwise healthier. The disturbing trend is even made more complicated by another troubling fact: a scarcity of new antibiotics in the market, the experts added.
Dr. Brad Spellberg, a member of the Infectious Diseases Society of America's (IDSA) Antimicrobial Availability Task Force, said that the development of antibiotic drugs is fading, and that we are coming to and end in terms of drugs. "We have organisms that are already resistant to every antibiotic we can throw at them," said Spellberg, who’s also an assistant professor of medicine at UCLA. "What will be increasingly seen in the coming decade is a dramatic decline in the availability of new antibiotics, which are desperately needed," he said.
Spellberg spoke during a telephone meeting from the IDSA yearly conference in Philadelphia.
Resistance to antibiotics, even to the latest drugs, has emerged to be such a concern with vicious gram-negative bacteria that clinical practitioners have found it necessary to reach back into the armory, bringing back to life polymyxin, a drug that had not been in use in 2 decades.
However, analytical studies of lab samples at a certain New York hospital indicated that pathogens are now also developing resistance to that drug.
According to Dr. Jason Kessler, lead author of a study describing the findings, which were scheduled to be presented at the conference, said that even though the incidence of gram-negative bacteria with resistance to polymyxin is presently at a quite low level of 6 percent, they observed more than relatively short two-year timeframe that the prevalence of resistance to that agent increased by about 50 percent.
"In addition, amongst all of the isolates we evaluated," Kessler, a clinical fellow in the division of infectious diseases at Columbia University in New York City, further said that over 30 percent were found to be resistant to five or more classes of antibiotics, "meaning that most of those isolates or most of those bacteria probably could only be treated with polymyxin, suggesting the prevalence of very highly drug-resistant gram-negative infection is on the rise in our facility."
Other infectious diseases are attacking younger people and those going home from hospitals into their respective communities and returning to hospitals.
For example, Clostridium difficile, a common cause of hospital infection, is currently targeting people who have not been in the hospital. The median age of these patients acquiring this infection outside of the hospital is 53 years, compared with 70 years for those in hospitals, according to study lead author Dr. Ghinwa Dumyati, an associate professor of medicine at the University of Rochester School of Medicine and Dentistry.
Dumvati said that it is not exactly obvious where these cases occurring in the community come from, but despite the fact that although in good shape, many of the people were on antibiotics, an indication that the medications remain "an important factor in the development of C. difficile in the community."
On a similar note, another study reported that methicillin-resistant Staphylococcus aureus (MRSA) is producing severe illness in younger, healthy people, although the infectious diseases do not lead to either death or long stays in the hospitals. According to study author Dr. Fernanda Lessa, of the U.S. Centers for Disease Control and Prevention, the fact that the people afflicted were younger and healthier may have led to the reduction in the risk of death.
Another study found that MRSA infections seen in emergency rooms have risen by 211percent between 2000 and 2008. Moreover, the incidence of infections caused by Acinetobacter baumannii, a multi-drug-resistant, gram-negative bacterial species, is also increasing, generally in the hospitals, according to the research team from Henry Ford Hospital in Detroit.
On the more optimistic standpoint, a meta-analysis of studies that looked at extremely drug-resistant tuberculosis discovered that more modern formulations of a group of antibiotic drugs called fluoroquinolones, seemingly did help people suffering from this bacterial infection.
But Dr. Neil Fishman, chair of the IDSA Antimicrobial Resistance Work Group, said that these findings have a certain degree of irony in it. "Fluoroquinolones have been implicated in causing a lot of problems with resistance and, to some extent, fluoroquinolones are the schoolyard bully of resistance," said Fishman, who is also the director of the Antimicrobial Management Program for the University of Pennsylvania Health System. He added that proper "stewardship," or careful use of antibiotic drugs would help curtail this trend.
At the teleconference, scientists also conveyed their hope that the attention being given to H1N1 (swine) flu virus at present could serve as a "wedge" issue, to further underscore the problem regarding antibiotics. At the moment, however, H1N1 is casting a shadow on the resistance issue, even though a lot of people yielding to H1N1 wind up being infected with disease-causing bacterial species as well.
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