杏吧原创

HOSPITAL superbugs thrive on sweat, say Danish researchers. They have found
that some antibiotics 鈥渓eak鈥� out of the body in sweat, and believe that bacteria
on patients鈥� skin become resistant through unrelenting exposure to the seeping
drugs. Simple physical contact would then be enough to pass on the bugs.

Niels H酶iby and his colleagues at the University of Copenhagen suggest that
doctors might have to limit the use of the most leaky antibiotics. These include
two widely used beta-lactam antibiotics called cephalosporins.

H酶iby and five other volunteers took five common antibiotics in turn. He then
measured how much came out in sweat samples from the armpit and forearm. Sweat
from all six people contained ceftazidime and ceftriaxone. Both are
鈥渢hird-generation鈥� cephalosporins, widely used for treating chest and urinary
tract infections.

H酶iby says that we all sweat continuously, although most of the time sweat
evaporates without our noticing. So populations of bacteria on the skin would be
reduced to those that survive exposure to the drug. 鈥淚 think the risk is highest
in the armpit and the perineum around the anus, as this is where you sweat most.
We know that these are areas where we see resistant Staphylococcus
bacteria,鈥� he says.

Antibiotic resistance coincided with the advent of leaky antibiotics, says
H iby. 鈥淲e鈥檝e found a mechanism which explains why we鈥檝e seen the development of
multiresistant staphylococci in the 1980s and 1990s,鈥� he says. 鈥淭hat鈥檚 when
these third-generation cephalosporins were introduced.鈥� H酶iby says the only
solution might be to use these drugs much more sparingly in future. 鈥淲hen we
know which antibiotics disturb the flora of the skin, we can choose antibiotics
that don鈥檛,鈥� he says.

In previous experiments on himself with ciprofloxacin, a broad-spectrum
fluoroquinolone antibiotic used to treat urinary tract infections, H酶iby showed
that bacteria on the skin developed resistance only three days after he
completed a week-long course of treatment. H酶iby says he鈥檚 now tested 25
antibiotics, and plans to test the theory further in patients who receive the
drugs as part of their treatment.

鈥淚t鈥檚 an important observation, no doubt about that,鈥� says Alan Johnson, an
antibiotic resistance expert at Britain鈥檚 Public Health Laboratory Service in
Colindale, London. He agrees that the phenomenon could be an important
unforeseen factor in the spread of hospital infections. But he warns against
hastily withdrawing the drugs, some of which are vital for intravenous treatment
of serious diseases.