Typing of Streptococcus Pyogenes Isolates from Patients with Acute Pharyngitis by Random Amplified Polymorphic DNA Fingerprinting Analysis

Abstract

Background: Streptococcus pyogenes is (group a β-hemolytic Streptococcus GAS) is an important gram-positive bacteria causes a wide spectrum of clinical diseases ranging from mild pharyngitis to life-threatening invasive infections. Random amplified polymorphic DNA (RAPD) fingerprinting is a PCR based technique which has been successfully used to appear genetic variation between closely related strains within the same species, it is more reliable technique for the typing of GAS isolates in epidemiological investigation. The current study aims to investigation genetic diversity of Streptococcus pyogenes isolates from acute pharyngitis patients by RAPD-PCR fingerprinting method.

Subject and methods: One hundred and twenty-five pharyngeal swabs were collected during the periods 21/10/2021 to 25/1/2022 from patients with acute pharyngitis. The standard bacteriological methods used for isolation and identification of S. pyogenes. Twenty clinical isolates of S.pyogenes, were genotyped by the RAPD-PCR fingerprinting method achieved by three arbitrary primers OPA13, OPA14 and P14

Results: out of 125 pharyngeal swabs, only 40 swabs give positive culture for S.pyogenes with a percentage of 32%. Amplification of genomic DNAs from the GAS isolates with OPA13 primer showed best results than other primers (OPA14 and P14) resulted 15 polymorphic DNA segment, phylogenetic analysis showed a high degree of genetic diversity, classified GAS isolates into 4 main clusters

Conclusion: The DNA fingerprinting by using RAP-PCR analysis is an effective method for evaluation the genetic diversity of GAS isolates