NEW YORK (Reuters Health) - In The New England Journal of Medicine this week, clinicians warn that some strains of Treponema pallidum, the bacterium that causes syphilis, have a mutation that makes them resistant to azithromycin.
“This is important because an increasing number of physicians are using azithromycin for treatment of patients with syphilis and for sexual contacts,” Dr. Sheila A. Lukehart, from Harborview Medical Center in Seattle, told Reuters Health.
The recommended treatment for syphilis is penicillin, to which there is currently no evidence of resistance. “However, penicillin injections are painful for the patient,” Dr. Lukehart noted, “and physicians have been looking for an alternative treatment that can be taken by mouth. Azithromycin has looked very hopeful in this regard.”
In their report, Dr. Lukehart and colleagues describe one syphilis patient, “among several cases that have been recognized,” who failed azithromycin. A specimen of T. pallidum from this patient revealed a mutation in the 23S ribosomal RNA genes and in vivo studies confirmed azithromycin resistance in a strain of T. pallidum containing this mutation.
Dr. Lukehart and colleagues subsequently found this azithromycin-resistance mutation in 11% to 88% of T. pallidum samples obtained at four different geographically diverse regions in the US and Ireland.
“These findings suggest that physicians should be very cautious about using azithromycin for treatment of syphilis until they know whether the strains in their geographical region are sensitive or resistant,” Dr. Lukehart told Reuters Health.
Drs. Edward W. Hook III and Rosanna W. Peeling of Birmingham, Alabama agree, writing in an editorial that azithromycin for syphilis “is not recommended unless careful follow-up can be ensured.”
Source: N Engl J Med 2004;351:123-125,154-158. [ Google search on this article ]
MeSH Headings:Biological Phenomena: Biological Phenomena, Cell Phenomena, and Immunity: Biological Sciences: Biology: Drug Resistance, Microbial: Genetics: Genetics, Microbial: Microbiologic Phenomena: Pharmacogenetics: Biological SciencesCopyright © 2002 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.
