Molecular Diagnosis of Streptococcus Pyogene by Detection Virulence Factors Genes from Clinical Isolates

Abstract

Background: The purpose of current study Isolation and identification of Streptococcus pyogene from patient, culturing bacteria, diagnosis Strept. pyogene infection by different methods and molecular detection by virulence factors genes SpeA, SpeC and speK and comparison between different type of methods to detection for Streptococcus pyogene. Methods: The clinical samples were taken during the period from October 2021 to end February 2022 for 141 patients suffering from acute tonsillitis, pharyngitis, otitis media, acute fever, and UTI patients. from both sexes the ages between 5 -60 years old. 102 samples showed bacterial growth in culture, and No growth was seen in other 39 samples from ENT unit in Marjan Teaching Hospital and Al- Sadiq Hospital in Hilla city, Babylon province, and Al- Hussiany Hospital Kerbala province. Results: The results shown differences in Sensitivity, Specificity and Accuracy between different detection methods, the standard method was molecular and when comparison with other methods shown Sensitivity 100%, Specificity 80.0 % Accuracy 81.8 % in vitik2 methods and Sensitivity 100%, Specificity 0.0 % Accuracy 9.1 % in direct detection methods. Molecular Detection of virulence genes was done through utilizing Specific PCR primers. SpeC found that was observed in 3 of 9 (33.33%) samples from patient’s throat swab of S. pyogenes detection by vitek 2 system. that contain this gene with the long length in (270bp), and SpeA gene of S. pyogenes it was found 3 isolates from 9 identifications in Vitek2 (33.33%) patient’s samples from throat of S. pyogenes has gene with the long length in (102bp). accuracy (100%) of diagnosis arised from 33.33%, 9 Specimen from throat with Spec gene and 33.33%, 9 Specimen from throat with SpeA gene and increase to the 100% when utilizing duplex RT PCR to detect the same bacterium. Conclusion: There is different methods for detection Strept. pyogene, the best one with high accuracy and specificity molecular method then Vitek2 methods and Direct detection method had very low accuracy and specificity.