Wide use of antibiotics allows bacteria to flourish

http://www.bendbulletin.com/health/3194317-151/wide-use-of-antibiotics-allows-bacteria-to-flourish

By Jane E. Brody / New York Times News Service
Published May 28, 2015

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C. diff. is a spore-forming, toxin-producing bacterium that can colonize the large intestine and wreak havoc there, causing frequent watery stools and severe dehydration. The spores are resistant to heat, acid and antibiotics; they can be washed away with soap and water but not the alcohol-based hand sanitizers widely used in health facilities. Thus, poor bathroom hygiene can spread the organism.

Dr. Dale Gerding, an infectious diseases specialist at Loyola University Chicago, said in an interview: “C. diff. is found in soil and water, even chlorinated water, and is a low-level contaminant in food. Most of us ingest C. diff. every day.”

In most people, the microorganisms that normally reside in the gut protect against C. diff. infection, he explained. That is, until antibiotics disrupt the healthy balance of microorganisms. Freed of competition, C. diff spores can germinate and reproduce unchecked, and not only in people with compromised immune systems.

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Since the early 2000s, hospitals have reported drastic increases in severe C. diff. infections, Dr. Daniel Leffler and Dr. J. Thomas Lamont of Beth Israel Deaconess Medical Center in Boston reported in the journal. The predominant virulent strain, NAP1, has a mortality rate three times as high as that associated with the less virulent forms most prevalent in decades past.

“The most important risk factor for C. difficile infection remains antibiotic use,” the doctors wrote. “Ampicillin, amoxicillin, cephalosporins, clindamycin and fluoroquinolones are the antibiotics that are most frequently associated with the disease, but almost all antibiotics have been associated with infection.”

Gerding said most antibiotics “are being used inappropriately, for things like upper respiratory infections that are caused by viruses.” Eating yogurt or taking commercially available probiotics while on an antibiotic have not proved protective, he said. But in England, where a program of more judicious use of antibiotics was put into effect, C. diff. infections have declined.

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