Antibiotic-resistant strains
Antibiotic-resistant strains
Overprescription of antibiotics and inappropriate use of broad-spectrum antibiotics have led to resistance, says Gregory Moran, MD, assistant professor of medicine at UCLA School of Medicine in Sylmar, CA. "E. coli resistance to quinolones was shown to correlate with the frequency of quinolone use in an institution. Antibiotic resistance is more prevalent in countries with OTC [over-the-counter] antibiotics," he reports.
Avoid contributing to antibiotic resistance by educating patients about the risks of antibiotics, and improving vaccination rates, Moran advises. "Broad-spectrum antibiotics should be avoided unless the organism is known to be resistant to first-line drugs, treatment failed with first-line drugs, or there is an allergy to first line agents," he adds.
"We have been able to keep up with antibiotic resistance by developing new classes of antibiotics, but it appears that we are running out of new classes of antibiotics, and the bugs may be winning," notes Moran.
Here are several infectious agents that are becoming antibiotic-resistant:
Methicillin-Resistant Staphylococcus aureus (MRSA): "There has been a large increase in resistance in recent years, especially in large teaching hospitals. Most MRSA strains are resistant to several antibiotics," says Moran. "Recurrence is common with any regimen, but combination regimens are most effective. Vancomycin is the drug of choice for serious MRSA infection, but it should only be used for infections, not for colonization."
Streptococcus pneumoniae: This was formerly sensitive to most penicillins and cephalosporins, but is now showing multiply resistant patterns to common antibiotics, including trimethoprim-sulfa, penicillin, and cephalosporins, notes Katherine L. Heilpern, MD, FACEP, interim residency director and assistant professor of the department of emergency medicine at Emory University School of Medicine in Atlanta, GA. "Help remind MDs to consider DRSP’ (drug-resistant S. pneumoniae) when they are considering their antibiotic choices," she says.
Drug resistant strains are no more or less virulent, stresses Moran. "They are only more difficult to treat. Vaccination is now more than ever for prevention," he says. "Resistant clones have now spread globally."
Escherichia coli. This is the number one pathogen of urinary tract infections and is demonstrating increasing resistance to trimethoprim-sulfa, Heilpern says. "We now recommend use of quinolones or other agents as first line for upper tract UTI (pyelonephritis). For cystitis, trimethoprim-sulfa is still okay in most parts of the country," she explains.
Vancomycin-resistant Enterococcus (VRE). "VRE is not a very virulent organism, but is well suited to surviving under antibiotic pressure," says Moran. "Risk factors include GI perforation, seriously ill or debilitated patients, prolonged hospitalization, and broad-spectrum antibiotics."
The first vancomycin-resistant strains were isolated in 1988, and have spread rapidly since then, notes Moran. "Reducing VRE can be accomplished by rapid identification and infection control measures, reduced routine use of broad-spectrum cephalosporins, increasing use of enterococcal-active agents, and reduced use of vancomycin," he says. (See material on the pros and cons of vancomycin inserted with this issue.)
Subscribe Now for Access
You have reached your article limit for the month. We hope you found our articles both enjoyable and insightful. For information on new subscriptions, product trials, alternative billing arrangements or group and site discounts please call 800-688-2421. We look forward to having you as a long-term member of the Relias Media community.