Evaluation of a PCR based approach to study the relatedness among Shigella sonnei strains

ABSTRACT

Infections caused by Shigella re a major cause of diarrheal disease in the developing and developed countries. The present study was conducted to apply and evaluate arbitrarily primed PCR [AP-PCR] for investigation of genetic relatedness among the strains of Shigella sonnei isolated from cases of acute diarrhea in Tehran. Totally, 60 S. sonnei strains isolated from children hospitalized due to enteritis at five hospitals in Tehran during 2003 and two sporadic isolates recovered in 1984 were investigated. Molecular typing was performed by AP-PCR. Depending on the number and size of amplified DNA bands, the strains were clustered into AP-PCR profiles. All strains of S. sonnei were typeable with this approach. AP-PCR generated nine indistinguishable bands ranged from 0.35 to 2.5 kbp in all studied strains. Only a single AP-PCR pattern was observed among the S. sonnei strains recovered in 2003. Two sporadic isolates recovered in 1984 showed different AP-PCR patterns compared to recent clinical isolates. Results suggest that a very homogeneous AP-PCR cluster types might be responsible for shigellosis caused by S. sonnei in Tehran in 2003. Further molecular analysis conducted on a larger selection of isolates could confirm our findings: