ANTIBIOOTEILLE RESISTENTTEJÄ BAKTEEREITA

[Bb]

Lähettäjä: Soijuv Lähetetty: 19.1.2005 8:35

Makrolidien ryhmään kuuluvista antibiooteista (esim. meillä aika yleisesti käytetty azithromysiiin (Zithromax) ja harvemmin käytetty klaritromysiini) on alkanut ilmaantua yhä useammin bakteerien resistenssiä koskevia tutkimustuloksia (esim. hengitysteiden tulehduksia yleisimmin aiheuttavaa steptokokkia vastaan). Seuraavassa artikkelissa (hollantilainen tutkimus) kerrotaan klaritromysiinille resistenttien bakteerien lisääntyvän huomattavasti klaritromysiinihoidon jälkeen:


Macrolide Resistance Emerges and Persists After Clarithromycin Therapy


Reuters Health Information 2004. © 2004 Reuters Ltd.

NEW YORK (Reuters Health) Dec 21 - Macrolide resistance emerges and persists in oropharyngeal flora after treatment with slow-release clarithromycin, according to a report in the November issue of Antimicrobial Agents and Chemotherapy.

Despite reports that macrolide resistance is increasing among Streptococcus pneumoniae (the most common respiratory tract pathogen), the authors explain, few reports have investigated the effect of macrolides on oropharyngeal flora.

Dr. Hans F. Berg from St. Elisabeth Hospital, Tilburg, the Netherlands and colleagues measured the effect of slow-release clarithromycin therapy on the development of resistance in oropharyngeal and nasopharyngeal flora in 296 patients.

After treatment with clarithromycin, the percentage of patients with macrolide-resistant flora increased from about 34% to 70%, the authors report. The percentage with macrolide-resistant flora persisted at least 8 weeks after treatment.

Results were similar when resistance was measured as the percentage of total flora resistant to macrolides, the report indicates. This rose from 3.4% before treatment to 21.1% after clarithromycin, compared with stable levels of 2.3% and 1.1% before and after placebo treatment.

Treatment was associated with a significant increase in the prevalence of resistance genes in both streptococci and staphylococci, the researchers note.

Although oropharyngeal carriage of Haemophilus parainfluenzae did not change significantly with clarithromycin treatment, the results indicate, nasal carriage of Staphylococcus aureus declined significantly (from 35.3% to 4.3%) after treatment with clarithromycin.

"Administration of a daily dose of 500 mg of slow-release clarithromycin for 2 weeks has major effects that are still present 8 weeks later," the authors conclude.

"This study provides indisputable evidence that treatment with clarithromycin results in a major effect on the sensitivity of the oropharyngeal flora to macrolides for at least 8 weeks."

Antimicrob Agents Chemother 2004;48:4183-4188.