Solunum Yolu Örneklerinde Streptococcus ID pneumoniae’nin Saptanmasında Optokin Duyarlılığı, Safrada Erime ve psaA Polimeraz Zincir Reaksiyonu Yöntemlerinin Yeri

Streptococcus pneumoniae; pnömoni, bakteriyemi ve menenjit gibi hayatı tehdit eden ciddi infeksiyonların yanısıra otit, sinüzit gibi sık rastlanan infeksiyonlara da yol açan önemli bir patojendir. S.pneumoniae’nin hızlı ve doğru tanısı, infekte hastaların uygun tedavi görmesinde son derece önemlidir. Çalışmamızda rutin tanıda kullandığımız fenotipik testlerin özgüllük ve duyarlılığının, altın standart yöntem olarak kullandığımız psaA PCR ile karşılaştırılması amaçlanmıştır. Klinik örneklerden izole edilen 90 adet alfa hemolitik streptokok suşu optokin duyarlılığı ve safrada erime-damlatma testlerine göre; S.pneumoniae olduğu bilinen (optokine duyarlı ve safrada erime-damlatma testi pozitif) 30 suş (Grup 1), S.pneumoniae olmayan (optokine dirençli ve safrada erime-damlatma testi negatif) 50 suş (Grup 2) ve S.pneumoniae şüpheli (optokine dirençli ama safrada erime-damlatma testi pozitif) 10 suş (Grup 3) olmak üzere 3 gruba ayrılmıştır. Tüm izolatlara psaA PCR ve safrada erime-tüp testi uygulanmış; Grup 1 deki suşlar pozitif, Grup 2 ve 3’teki suşlar ise negatif olarak bulunmuştur. Grup 3’teki 10 suşa API 20 Strep testi yapılmış ve viridans grup streptokok olarak tanımlanmıştır. Bu bulgulara göre safrada erime-tüp testinin; damlatma testine göre daha özgül, psaA PCR yöntemiyle ise benzer özgüllüğe sahip olduğu görülmüştür.

The Role of Optochin Sensitivity, Bile Solubility and psaA Polymerase Chain Reaction Methods in the Diagnosis of Streptococcus pneumoniae in Respiratory Tract Samples

Streptococcus pneumoniae; in addition to serious life-threatening infections such as pneumonia, bacteremia and meningitis, is also an important pathogen which causes common infections such as otitis and sinusitis. The rapid and accurate diagnosis of S.pneumoniae is extremely important for the appropriate treatment of infected patients. In our study, we aimed to compare the specificity and sensitivity of the phenotypic tests used in routine diagnosis with the psaA PCR we used as the gold standard method. 90 strains isolated from the clinical specimens were grouped according to their optochin sensitivity and bile solubility: 30 S.pneumoniae strains (optochin sensitive and bile solubility-drip test positive) (Group 1), 50 non-pneumococcus strains (optochin resistant and bile solubility-drip test negative) (Group 2) and 10 S.pneumoniae suspicious strains (optochin resistant but bile solubility-drip test positive) (Group 3) psaA PCR and bile solubility-tube test were applied to all isolates; the strains in Group 1 were positive and the strains in Groups 2 and 3 were negative. The 10 strains in Group 3 were determined as viridans group streptococci in API 20 Strep test. According to these findings, bile solubility-tube test was found to be more specific than the drip test and similar to psaA PCR method.

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  • 1. Carvalho MGS, Steigenralt AG, Thompson T, et al. Confirmation of nontypeable Streptococcus pneumoniae-like organisms isolated from outbreaks of epidemic conjunctivitis as Streptococcus pneumoniae. J Clin Microbiol. 2003;41(9):4415-17. https://doi.org/10.1128/JCM.41.9.4415-4417.2003
  • 2. El Aila NA, Emler S, Kaijalainen T, et al. The development of a 16S rRNA gene based PCR fort he identification of Streptococcus pneumoniae and comparison with four other species specific PCR assays. BMC Infect Dis. 2010;10:104. https://doi.org/10.1186/1471-2334-10-104
  • 3. Harimurti K, Saldi SR, Dewiasty E, et al. Nasopharyngeal carriage of Streptococcus pneumoniae in adults infected with human immunodeficiency virus in Jakarta, Indonesia. J Infect Public Health. 2016;9 (5):633-8. https://doi.org/10.1016/j.jiph.2016.01.004
  • 4. Ing J, Mason EO, Kaplan SL, et al. Characterization of nontypeable and atypical Streptococcus pneumoniae pediatric isolates from 1994 to 2010. J Clin Microbiol. 2012;50(4):1326-30. https://doi.org/10.1128/JCM.05182-11
  • 5. Kaijalainen T, Rintamaki S, Herva E, et al. Evaluation of gene-technological and conventional methods in the identification of Streptococcus pneumoniae. J Microbiological Methods. 2002;51(1):111-8. https://doi.org/10.1016/S0167-7012(02)00061-1
  • 6. Kellogg JA, Bankert DA, Elder CJ, et al. ldentification of Streptococcus pneumoniae revisited. J Clin Microbiol. 2001;39(9):3373-5. https://doi.org/10.1128/JCM.39.9.3373-3375.2001
  • 7. Levinson W. ÇE: Şener B, Esen B. Tıbbi Mikrobiyoloji ve İmmünoloji. 14. Baskı, s.123, LANGE, Güneş Tıp Kitabevleri (2018).
  • 8. Martin-Galiano AJ, Balsalobre L, Fenoll A et al. Genetic characterization of optochin-susceptible viridans group streptococci. Antimicrob Agents Chemother. 2003;47(10):3187-94. https://doi.org/10.1128/AAC.47.10.3187-3194.2003
  • 9. Messmer TO, Sampson JS, Stinson A, et al. Comparison of four polymerase chain reaction assays for specifity in the identification of Streptococcus pneumoniae. Diagn Microbiol lnfect Dis. 2004;49(4):249-54. https://doi.org/10.1016/j.diagmicrobio.2004.04.013
  • 10. Miernyk KM, DeByle CK, Rudolph KM. Evaluation of two matrices for long-term, ambient storage of bacterial DNA. Biopreserv Biobank. 2017;15(6):529-34. Epub 2017 Nov 13. https://doi.org/10.1089/bio.2017.0040
  • 11. Morrison KE, Lake D, Crook J, et al. Confirmation of psaA in all 90 serotypes of Streptococcus pneumoniae by PCR and potential of this assay for identification and diagnosis. J Clin Microbiol. 2000;38(1):434-7.
  • 12. Pikis A, Campos JM, Rodriguez WJ, et al. Optochin resistance in Streptococcus pneumoniae: mecha nism, significance, and clinical implications. J lnfect Dis. 2001;184(5):582-90. https://doi.org/10.1086/322803
  • 13. Sanz JC, Ríos E, Rodríguez-Avial I, et al. Identification of Streptococcus pneumoniae lytA, plyA and psaA genes in pleural fluid by multiplex real-time PCR. Enferm Infect Microbiol Clin. 2018;36(7):428-30. https://doi.org/10.1016/j.eimc.2017.07.007
  • 14. Scott JAG, Marston EL, Hall AJ, et al. Diagnosis of pneumococcal pneumonia by psaA PCR analysis of lung aspirates from adult patients in Kenya. J Clin Microbiol. 2003;41(6):2554-9. https://doi.org/10.1128/JCM.41.6.2554-2559.2003
  • 15. Topçu AW, Söyletir G, Doğanay M. Enfeksiyon hastalıkları ve mikrobiyolojisi-etkenlere göre enfeksiyonlar, 4.Baskı, s.1794, Nobel Tıp Kitabevleri (2017).
  • 16. Tsar HY, Hsueh PR, Teng LJ, et al. Bacteremic pneumonia caused by a single clone of Streptococcus pneumoniae with different optochin susceptibilities. J Clin Microbiol. 2000;38(1):458-9.
  • 17. Veerasamy J, Jayarajan J. Atypical pneumococcal isolate from blood. Int J Appl Basic Med Res. 2018;8(1):61-3. https://doi.org/10.4103/ijabmr.IJABMR_459_16
  • 18. Verhelst R, Kaijalainen T, De Baere T, et al. Comparison of five genotypic techniques for identification of optochin-resistant pneumococcus-like isolates. J Clin Microbiol. 2003;41(8):3521-5. https://doi.org/10.1128/JCM.41.8.3521-3525.2003
  • 19. Whatmore AM, Efstratiou A, Pickerill AP, et al. Genetic relationships between clinical isolates of Streptococcus pneumoniae, Streptococcus oralis, and Streptococcus mitis: characterization of “Atypical” pneumococci and organisms allied to S.mitis harboring S.pneumoniae virulence factorencoding genes. Infect lmmun. 2000;68(3):1374-82. https://doi.org/10.1128/IAI.68.3.1374-1382.2000
  • 20. Winn W, Allen S, Janda W, et al. Koneman’s Color Atlas and Textbook of Diagnostic Microbiology. Gram-Positive Cocci Part II: Streptococci, Enterococci, and the ‘Streptococcus-Like’ Bacteria, 6.baskı, s.672- 764, Lippincott Williams Wilkins, Philadelphia (2006).