Distribution of Virulence genes in Streptococcus pneumoniae Isolated from Different Baghdad Hospitals

Abstract

Streptococcus pneumoniae causes serious infections (pneumonia, meningitis and bacteremia) with significant morbidity and mortality rates. The goal of this study is to isolate and identify S. pneumoniae from clinical samples in Baghdad City hospitals in order to explore the presence of three virulence genes (lytA, ply and psaA) in clinical isolates. A total of 120 separate clinical samples were obtained from inpatients and outpatients with upper and lower respiratory tract infections at different hospitals in Baghdad. Twenty-five isolates of S. pneumoniae were identified by using cultural, morphological and biochemical characteristics as well as the diagnosis by VITEK2 system. Clinical samples were including sputum 19 isolates (76%) and urine 6 isolates (24%). The results of collected specimens showed that male's percentage is highest than female's patients, which was out of 25 isolates are 15 (60%) males and 10 (40%) females, The results also showed that it is much more common in elderly people than in younger people. The genomic DNA of bacterial isolates was applied in a polymerase chain reaction (PCR) to amplify certain genes. The PCR results were: Six isolates (24%) show positive results for the presence of lytA gene. Five isolates (20%) showed positive results for the presence of ply gene. Twenty-three isolates (92%) show positive results for the presence of psaA gene. As concluded from the present study, that the results exhibited that the presence of the virulence genes can be considered as a serious issue.