THE ANTIBIOTIC SUSCEPTIBILITY AND PREVALENCE OF ADHESION GENES IN STREPTOCOCCUS PNEUMONIAE ISOLATES DETECTED IN CARRIER CHILDREN IN TEHRAN

Background and Aim:Pharyngeal carriers are the source and a transitional vector of invasive. Attachment is the first step of the pathogenicity. Strains of Streptococcus as normal flora can cause the diseases in certain circumstances. Adhesin proteins of these bacteria play a fundamental role in attachment and colonization .In the present study, 5genes which encode surface proteins include phtD, pspC, phtE, lytA , rrgA were evaluated in Streptococcus pneumoniae isolates collected from 4 main care centers and Children’s Medical Center of TehranMethods:308 nasopharyngeal swabs specimens were collected from children under 6 years old. Identification of S.pneumoniae isolates was performed using biochemical tests and were confirmed by PCR to have cpsA gene. The excistance of phtD, phtE, pspC, lytA and rrgA genes were studied by PCR amplification assaysResults:From 308 nasopharyngeal swabs, 102 isolates of S.pneumoniae were confirmed after identification tests. Among these isolates, 87 (85.2%), 54 (%52.9), 51 (%50), 43 (%42.1) and 31 (30.3%) were positive for lytA, rrgA, phtE, pspC and phtD genes respectivelyConclusion:Our studies showed that cpsA of S. pneumoniae is one of the major characteristic genetic markers for diagnostic purposes. Among five adhesin genes, lytA was the most frequent gene and the strain have the both combination of rrgA and lytA was predominant pattern. These findings could be very useful for design of further studies about vaccine against S. pneumoniae in our country.

Keywords:

S.pneumoniae , Nasopharynx , Adhesion genes , PCR