Streptococcus pneumoniae'da makrolid direnç mekanizmalarının Araştırılması: 2005-2008, Marmara Üniversitesi hastanesi sonuçları
Amaç: Bu çalışmada enfeksiyon etkeni olarak izole edilen Streptococcus pneumoniae izolatlarında, makrolid direncinin fenotipik karakteristiklerinin ve genetik determinantlarının belirlenmesi amaçlanmıştır. Gereç ve Yöntemler: Eritromisin direnci gösteren 50 S. pneumoniae izolatının 14-, 15- üyeli makrolid ve linkozamid duyarlılıkları disk difüzyon ve sıvı mikrodilüsyon yöntemleriyle saptanmıştır. Makrolid direnç fenotiplerini belirlemek üzere eritromisin-klindamisin çift disk testi kullanılmıştır. Makrolid direncinin genetik determinantları, mef(E)/(A), erm(B) ve erm(TR)nin saptanmasında Polimeraz Zincir Reaksiyonu (PZR) yöntemi kullanılmıştır. Bulgular: İzolatlarımızın % 86sı Makrolid-Linkozamid Streptogramin B (MLSB) (%76 cMLSB ve %10 iMLSB), % 14ü M fenotipi göstermiştir. PZR sonuçlarına göre 18 izolatta (% 36) tek başına erm(B); 11 izolatta (% 22) tek başına mef(E)/(A) geni; geri kalan 21 (% 42) izolatta ise her iki gen birlikte saptanmıştır. erm(B) geni taşıyan tüm izolatlar (%78), yüksek düzey makrolid ve linkozamid direnci gösterirken, mef(E)/(A) genini tek başına taşıyan 11 izolatın 7si M, 4ü MLSB fenotipi göstermiştir. M fenotipindeki izolatların makrolid MİKleri ise düşük düzeyde bulunmuştur. Sonuç: Çalışmamızda mef(A)/(E) geninin tek başına ya da erm(B) ile birlikte izolatların %64ü tarafından taşındığının gösterilmesi ayrıca M fenotipine sahip izolatların oranının da oldukça yüksek (%14) bulunması, aktif makrolid pompasının, ribozomal hedef mutasyonuyla birlikte hastanemiz pnömokok izolatlarının makrolid direncinde çok önemli rolü olduğunu ortaya koymaktadır.
Investigation of macrolide resistance mechanisms in streptococcus pneumoniae: Results of Marmara University hospital between 2005-2008
Objective: In this study, we aimed to determine the phenotypic characteristics and genetic determinants of macrolide resistance in the clinical isolates of Streptococcus pneumoniae. Materials and Methods: In 50 erythromycin resistant S. pneumoniae isolates, 14-, 15- membered macrolides and lincosamide susceptibilities were determined by both disk diffusion and broth microdilution methods. The erythromycin-clindamycin double disk method was applied for the detection of macrolide resistance phenotypes. Genetic determinants of macrolide resistance, erm(B), erm(TR) and mef(A)/(E) were investigated by Polymerase Chain Reaction (PCR). Results: The percentages of the isolates presenting Macrolide-Lincosamide-Streptogramin B (MLSB) and M phenotypes were 86% (cMLSB phenotype: 76%; iMLSB phenotype: 10%) and 14%, respectively. According to the PCR results, 18 isolates (36%) had erm(B) gene, 11 isolates (22%) had mef(E)/(A) gene and the remaining 21 (%42) isolates had both erm(B) and mef(A)/(E) genes. All erm(B) positive isolates (78%) presented high level macrolide and lincosamide resistance. Seven out of 11 isolates carrying the mef(A)/(E) gene alone presented M phenotype with low level macrolide MICs. Conclusion: The demonstration of the mef(A)/(E) gene either alone or together with erm(B) in a high proportion of the isolates (64%) in addition to the high rate of M phenotype (14%) signifies that active macrolide efflux together with the ribosomal target mutation has a significant role in the macrolide resistance of our pneumococcal isolates.
___
- 1. Musher, D. M. Streptococcus pneumoniae. In: Mandell GL., Bennett JE., Dolin R., eds. Mandell, Douglass and Bennett' s Principles and Practice of Infectious Diseases. New York: John Wiley & Sons, 2004:2392-2411. doi:10.1086/507699
- 2. Liñares J, Ardanuy C, Pallares R, Fenoll A. Changes in antimicrobial resistance, serotypes and genotypes in Streptococcus pneumoniae over a 30-year period. Clin Microbiol Infect 2010;16(5):402-410. do.:10.1111/j.1469- 0691.2010.03182.x
- 3. Farrell DJ, Couturier C, Hryniewicz W. Distribution and antibacterial susceptibility of macrolide resistance genotypes in Streptococcus pneumoniae: PROTEKT year 5 (20032004). Int J Antimicrob Agents 2008;31:245249. doi:10.1016/j.ijantimicag.2007.10.022
- 4. The European Antimicrobial Resistance Surveillance System (EARSS) Annual Report 2007 [http://www.rivm.nl/earss/result/Monitoring_repor ts/Annual_reports.Jsp]
- 5. The European Antimicrobial Resistance Surveillance System (EARSS) Annual Report 2008 [http://www.rivm.nl/earss/result/Monitoring_repor ts/Annual_reports.Jsp].
- 6. Varaldo PE, Montanari MP, Giovanetti E. Genetic elements responsible for erythromycin resistance in streptococci. Antimicrob Agents Chemother 2009;53(2):343-353. doi: 10.1128/AAC.00781-08
- 7. Leclercq R, Courvalin P. Resistance to macrolides and related antibiotics in Streptococcus pneumoniae. Antimicrob Agents Chemother 2002;46(9): 2727-2734. doi: 10.1128/AAC.46.9.2727-2734.2002
- 8. Camilli R., Del Grosso M., Iannelli F., Pantosti A... New genetic element carrying the erythromycin resistance determinant erm(TR) in Streptococcus pneumoniae: insertion sites and association with other genetic elements. Antimicrob. Agents Chemother 2008;52:619 625. doi: 10.1128/AAC.01081-07
- 9. Sener B, Köseoglu O, Gür D, Bryskier A. Mechanisms of macrolide resistance in clinical pneumococcal isolates in a university hospital, Ankara, Turkey. J Chemother 2005;17(1):31-35.
- 10. Gür D, Mülazımoğlu L, Ünal S. In Vitro susceptibility of respiratory isolates of streptococcus pneumoniae and streptococcus pyogenes to telithromycin and 11 other antimicrobial agents: Turkish results of e BASKETT II surveillance study. Mikrobiyol Bul 2007;41(1):1-9.
- 11. Gülay Z, Özbek ÖA, Biçmen M, Gür D. Macrolide resistance determinants in erythromycin- resistant streptococcus pneumoniae in Turkey. Jpn J Infect Dis 2008;61, 490-493.
- 12. Leclercq R. Mechanisms of resistance to macrolides and lincosamides: Nature of the resistance elements and their clinical implications. Clin Infect Dis 2002; 34: 482492. doi: 10.1086/324626
- 13. Hasdemir U. Çoklu ilaç direncinde bakteri hücre duvarı organizasyonunun ve aktif pompa sistemlerinin rolü. Mikrobiyoloji Bülteni 2007; 41(2): 309-327.
- 14. Lynch III JP, Martinez FJ. Clinical relevance of macrolide-resistant Streptococcus pneumoniae for community-acquired pneumonia. Clin Infect Dis 2002; 34 (Suppl 1): S27-S46. doi: 10.1086/324527
- 15. Daly MM, Doktor S, Flamm R, Shortridge D. Characterization and prevalence of MefA, MefE, and the associated msr(D) gene in Streptococcus pneumoniae clinical isolates. J Clin Microbiol 2004;42(8):3570-3574. doi: 10.1128/JCM.42.8.3570-3574.2004
- 16. Streptococci and related genera. In: Baron EJ, Peterson LR, Finegold SM, eds. Bailey and Scotts Diagnostic Microbiology. 9th ed. St Louis, MO: Mosby, 1994; 333352.
- 17. Clinical and Laboratory Standards Institute. Performance standards for antimicrobial susceptibility testing. Sixteenth informational supplement. M100-S19. Wayne, PA. CLSI; 2009.
- 18. Clinical and Laboratory Standards Institute. Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically: approved Standard, 7th ed. Clinical and Laboratory Standards Institute, Wayne, PA. CLSI; 2006.
- 19. Amezaga MR., Carter PE., Cash P., McKenzie H.. Molecular epidemiology of erythromycin resistance in Streptococcus pneumoniae isolates from blood and noninvasive sites. J Clin Microbiol 2002;40:33133318.
- 20. Seppälä H, Skurnik M, Soini H, Roberts MC, Huovinen P. A novel erythromycin resistance methylase gene (ermTR) in Streptococcus pyogenes. Antimicrob Agents Chemother 1998;42(2):257-262.
- 21. Clancy, J., Petitpas J., Dib-Hajj F., et al. Molecular cloning and functional analysis of a novel macrolide-resistance determinant, mefA, from Streptococcus pyogenes. Mol Microbiol 1996;22:867-879. doi: 10.1046/j. 1365- 2958.1996.01521.x
- 22. Tait-Kamradt, A., Clancy J., Cronan M., et al. mefE is necessary for the erythromycin-resistant M phenotype in Streptococcus pneumoniae. Antimicrob Agents Chemother 1997;41:2251- 2255.
- 23. Reinert RR, Lütticken R, Bryskier A, Al-Lahham A. Macrolide-Resistant Streptococcus pneumoniae and Streptococcus pyogenes in the Pediatric Population in Germany. Antimicrob Agents Chemother 2003;47(2):489-493. do.: 10.1128/AAC.47.2.489-493.2003
- 24. Kataja J, Huovinen P, Seppala H. Erythromycin resistance genes in group A streptococci of different geographical origins. J Clin Microbiol 2000; 46:789-792. doi: 10.1093/jac/46.5.789
- 25. Klaassen CH, Mouton JW. Molecular detection of the macrolide efflux gene: to discriminate or not to discriminate between mef(A) and mef(E). Antimicrob Agents Chemother 2005 Apr;49(4):1271-1278. doi: 10.1128/AAC.49.4.1271-1278.2005