Screening of macrolide resistance locus in Treponema pallidum subsp. pallidum in the Czech Republic
Abstract number: P698
Matejková P., Flasarová M., Zákoucká H., Borek M., Kremenová S., Arenberger P., Woznicová V., Weinstock G.M., Smajs D.
Objectives: Due to alergies to penicillin, macrolide regimens are frequently applied in the treatment of syphilis. Unlike penicillin, macrolide treatment represents a risk of treatment failure due to chromosomally encoded resistance in Treponema pallidum subspecies pallidum. A2058G mutation in the 23S rDNA locus was described to cause erythromycin resistance in syphilis. Molecular detection of syphilis represents the only available test to reveal macrolide resistance in clinical isolates, because T. pallidum can not be cultured in vitro. Our aim was to assess the incidence of this mutation among clinical isolates in the Czech Republic.
Methods: Primary screening of clinical specimen included nested PCR detection of two T. pallidum specific loci (tmpC, polA). In PCR positive samples, 23S rDNA was amplified. Nested PCR protocol to detect 23S rRNA gene was developed and direct Sanger sequencing of PCR products was applied to detect mutations in corresponding part of the 23S rRNA gene.
Results: The set of 28 clinical isolates with detectable genetic material were collected from 22 patients in the Czech Republic in the time period 20052008. 14 patients (63.6%) were infected with macrolide sensitive strains of T. pallidum. Four patients (18.2%) were diagnosed with a strain bearing the A2058G transition and four patients (18.2%) with a strain bearing the A2059G mutation (spiramycin treatment failure was reported in one of these patients). There was a complete concordance of multiple samples collected from the same patient.
Conclusions: Screening of clinical samples revealed a novel mutation at the position 2059 of the T. pallidum 23S rRNA gene. This mutation causes macrolide resistance in several other bacteria.
Our results show that macrolide resistant isolates of T. pallidum bearing A2058G and A2059G mutations are relatively abundant in the Czech Republic, possibly causing macrolide treatment failures in penicillin alergic patients.
This work was supported by the grants from the Internal Grant Agency of the Ministry of Health of the Czech Republic (NR/89674/2006) and from the Grant Agency of the Czech Republic (310/07/0321).
|Session name:||19th European Congress of Clinical Microbiology and Infectious Diseases|
|Location:||Helsinki, Finland, 16 - 19 May 2009|
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