Isolation, Identification and Biochemical profile of Streptococcus pyogenes from Sore throat

Abstract

Throat infection includes tonsillitis and pharyngitis may be caused by a wide variety of microbial agents, but the most common bacterial cause is group A β hemolytic Streptococci. However, prescription of antibiotics due to clinical diagnosis only could disturb the microbiota and result in antibiotic resistant. So that, the aim of this study is to investigate the presence of Streptococcus pyogenes as common cause of throat infection.: 591 throat swabs samples from tonsils and auropharynx were obtained from 308 participants most of them were healthy. Throat swabs were cultured followed by isolation of S. pyogenes and other types of bacteria, which were subjected to morphological, microscopic and biochemical analysis include the biochemical tests and sensitivity tests. PCR confirmation was performed for commonly isolated S. pyogenes using spy1258 primer. Among all isolated bacteria (556 isolates), S. pyogenes represented the most common (65%), 13% of them were positive by PCR using spy 1258 primer, while other Streptococci represented 21%. Other bacteria formed 3.7% of all isolated bacteria. Isolation of 12 isolates of Group L streptococci as well as Staphylococcus chromogenes from throat were a remarkable finding in this study. The results also revealed a significant correlation between sore throat caused by Group A Streptococci and extraeosaphageal reflux (laryngeopharyngeal reflux LPR). The low sensitivity of Spy 1258 primer and the variability in S. pyogenes genome sequence necessitate developing new primers according to the environmental and geographical distribution of S. pyogenes isolates