The use of rapid antigen testing and matrix-assisted laser desorption/ionization-time of flight mass spectrometry in the diagnosis of group a beta-hemolytic streptococci in throat swab samples


Deniz R., Aktaş E., BARIŞ A., BAYRAKTAR B.

Turkish Journal of Medical Sciences, cilt.48, sa.5, ss.939-944, 2018 (SCI-Expanded, Scopus, TRDizin)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 48 Sayı: 5
  • Basım Tarihi: 2018
  • Doi Numarası: 10.3906/sag-1712-101
  • Dergi Adı: Turkish Journal of Medical Sciences
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, TR DİZİN (ULAKBİM)
  • Sayfa Sayıları: ss.939-944
  • Anahtar Kelimeler: MALDI-TOF MS, rapid antigen test, Streptococcus pyogenes, tonsillopharyngitis
  • Sağlık Bilimleri Üniversitesi Adresli: Evet

Özet

Background/aim: We aimed to evaluate the efficacy of a rapid antigen test in detecting group A beta-hemolytic streptococci (GAS) in throat samples in comparison with the culture method and to compare the efficiency of matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) and traditional methods in identifying GAS in cultures. Materials and methods: A total of 3668 throat samples from patients with a prediagnosis of tonsillopharyngitis were assessed by the QuickVue+Strep A antigen test and culture. For GAS identification from cultures, bacitracin sensitivity, PYR, and latex agglutination tests and MALDI-TOF MS were used. Results: A total of 567 (15.5%) and 536 (14.6%) of the samples were positive for GAS culture and rapid antigen testing, respectively. The sensitivity and specificity of the rapid antigen test compared to culture was 89.07% and 99%, respectively, while positive and negative predictive values were 94.22% and 98.02%. Traditional methods were in full concordance with MALDI-TOF-MS for all 567 isolates. In all densities of growth in culture, the time to diagnosis with MALDI-TOF MS was significantly lower than with traditional identification tests. Conclusion: This study shows that both the rapid antigen testing of samples and bacterial identification with MALDI-TOF MS contribute much to the rapid diagnosis of GAS tonsillopharyngitis.