• Soil microbes harbor nasty antibiotic resistance genes

    By Wynne Parry, LiveScience 

    Bacteria that live in the soil seem to be swapping antibiotic-resistance genes with other, more dangerous bacteria ? the ones that cause devastating infections in humans, a new study indicates.

    When a team of researchers analyzed bacteria they had grown from soil samples, they found the microbes were harboring seven genes identical to those that enabled harmful bacteria to resist antibiotics. These genes are active against antibiotics within five major drug classes, they write.

    It is highly unlikely these genes evolved independently in the soil microbes and the disease-causing ones, they concluded.

    "The sequences of the resistance genes are identical, but they are in organisms that are very, very different, so we know they have been shared between these organisms," said study researcher Kevin Forsberg, of Washington University School of Medicine, in an audio interview released by the journal Science, where the research appears this week.

    Bacteria, even members of different species, can swap genes. This ability gives the microbes incredible flexibility, Forsberg said. [ Tiny & Nasty: Images of Things That Make Us Sick ]

    "If they don't have a gene or function necessary for survival in a given environment, they might survive and thrive nonetheless by borrowing a gene or genes from their neighbor," he said.

    So far, it's not clear whether the genes are moving from the clinic to the soil or from the soil to the clinic, but Forsberg said he suspects both.

    The team looked at soil form 11 samples from a variety of ecosystems in the United States, such as forest, urban and farmland.

    They focused on soil because it contains a great diversity of microbial inhabitants, including Streptomyces bacteria. The compounds these bacteria produce to fight off other bacteria have provided the majority of naturally produced antibiotics. Antibiotic resistance, the ability of other bugs to fight of these attacks, is also believed to have evolved in the soil.

    And finally, soil is receiving increasing amounts of antibiotics as a result of agriculture.

    "Upwards of 80 percent of the antibiotics by weight are used in animal feed to promote growth, and these antibiotics end up in the surrounding environment, including soil," Forsberg said.

    The overuse of antibiotics as medication can give rise to resistance among disease-causing bacteria, and so can the flood of antibiotics into the environment.

    Bacteria in both settings are acquiring more resistance genes and swapping them because they have a reason — the pressure from more, and new, antibiotics. The gene sharing means humans’ treatment of one group is likely to affect the other, he said.

    Forsberg and his colleagues grew the soil bacteria in media containing antibiotics to select for those with antibiotic-resistance genes. They found not only exact replicas of known resistance genes but also new ones.

    When fed to a laboratory strain of the bacterium Escherichia coli,one unrecognized gene helped the E. coli fight off large doses of an antibiotic used to treat tuberculosis, they found. The antibiotic was cycloserine.

    "The fact we are finding resistance genes that we haven't seen before means there is more resistance out there," Forsberg said.

    While the swapping of resistance genes between soil bacteria and those that cause disease has serious implications for health, there's no way to prevent it.

    "Bacteria developed resistance well before humans existed, and they have been trading genes for even longer," Forsberg said. "What we can do is diminish the problem by giving bacteria less reason to have these antibiotic-resistance genes."

    This means more prudent use of antibiotics, he said.

    The research appears in tomorrow’s (Aug. 31) issue of the journal Science.

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  • Prisoners using antibiotic ointment as hair gel -- why that's worrisome

    By Diane Mapes

    We've all had those fuzzy mornings where we've nearly brushed our teeth with Neosporin, but a new study presented at an annual meeting of epidemiologists has found that prison inmates are purposefully misusing over-the-counter topical antibiotics as grooming aids.

    The study, which asked 822 inmates at two New York State prisons about their use of OTC antibiotics such as Bacitracin (an ingredient found in Neosporin), found that 29 percent of the men and 28 percent of the women had used the ointment for dry skin, 18 percent of men and 15 percent of women had used it as a lip balm, 8 percent of men and 3 percent of women had used it as hair gel and 6 percent of men had slathered the ointment onto their face as a shaving cream.

    "I think one reason they used the antibiotic ointments in these ways is because they didn't know they shouldn't," says Carolyn Herzig, a PhD candidate in the Department of Epidemiology at the Mailman School of Public Health at Columbia University and lead author of the study. "Or it might be that they didn't have easy access to other products."

    Misuse or overuse of antibiotics is worrisome because it can lead to strains of antimicrobial resistant pathogens resulting in the emergence of multi-drug resistant organisms such as MRSA, a strain of staph infection that's now resistant to methicillin, amoxicillin, penicillin, oxacillin, and many other antibiotics.

    These pathogens are already a problem in prisons, and the "misuse of antibiotics in these facilities might exacerbate this issue," Herzig explains.

    "We don't know specifically whether the overuse of topical antibiotics would lead to MRSA -- we don't have the data to demonstrate that -- but in many cases, in general, the overuse and misuse of antibiotics can lead to antibiotic resistance," says Herzig. "That's exactly what the concern is."

    Herzig and her team of researchers tapped prison inmates as they were being admitted to two New York State maximum security prisons -- one men's and one women's. (The researcher declined to reveal the names of the prisons.)

    "The question we asked was, 'Have you used antibiotic ointment in the past six months?'" she says. "They were entering the prison facilities from either jails or prisons or possibly, the community. If they served a sentence longer than six months, then they had used the ointments in other prisons or in county lockup. It's also possible that some of them used the ointments while they were not incarcerated but I would say the majority of them used them while incarcerated."

    Medical personnel do dispense antibiotic ointments to inmates as needed; however, other items -- such as hair gel and shaving cream -- are harder to come by, Robin Campbell, press secretary for the New York City Department of Corrections (which includes Rikers Island and other Borough facilities), said in a statement. 

    "Facility medical personnel dispense antibiotic creams and ointments, like foot gels, to inmates on an as needed basis," he said in an email. "Although inmates may purchase some personal hygiene products, like shampoo, toothpaste and deodorant, from the facility commissary, shaving cream, lip balm and hair gel are prohibited due to security concerns."

    Antibiotic resistance concerns aside -- would a Neosporin-like cream even work as a beauty aid? "I think they probably worked as well as Vaseline," says Herzig. "And I really think if they'd had lotion or Vaseline, that's what they would have used."

    The study's findings were presented this week at the 39th Annual Educational Conference and International Meeting of the Association for Professionals in Infection Control and Epidemiology in San Antonio, Texas. Funded by the National Institute of Allergy and Infectious Diseases, the study was the first of its kind to report on the widespread misuse of topical antibiotics among inmates.

    While Herzig says she's been unable to find any studies on the misuse of over-the-counter antibiotic ointments in everyday life, she is curious about inappropriate use of these products in normal populations.

    "I've spent a lot of time looking at the literature to see if there's a comparable study that shows how people use these ointments in a community, but I haven't seen anything that reports that information," she says. "I suspect it is happening, though."

    Melissa Rowton, a 41-year-old customer service trainer from Seattle, says she's used antibiotic ointments on blemishes before -- although she doesn't do it very often.

    "I've used Neosporin for pimples and have a friend who swears by it," says Rowton. "It makes sense when they are often caused by bacteria. I wash and dry my face thoroughly and dab a small amount on any problem area before bed."

    Herzig says none of the prisoners who answered the open-ended questionnaire indicated they'd used the antibiotic ointments in this way. However, in addition to using the topical antibiotics as hair gel, moisturizer and lip balm, many said they'd used the products in ways that were closer to their intended use.

    "We got many reasons," she says. "Some used them for skin injuries, skin conditions including eczema and acne, fungal infection, or for new tattoos. We're not suggesting people should use antibiotics for all those reasons. But they're more appropriate than using them for lip balm or moisturizer."

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