Survival of Shigella dysenteriae Type 1 on Fomites

Abstract

Studies have shown that various objects, such as utensils, toys,a nd clothes, can serve as vehicles for transmission of Shigella spp. Shigellae can become viable but non-culturable (VBNC)when exposed to various environmental conditions as shown in earlier studies. The present study was carried out to detect VBNC Shigella dysenteriae type 1 on various fomites by direct viable counting, polymerase chain reaction (PCR), and fluorescent antibody methods.S.dysenteriae type 1 was inoculated onto cloth, wood, plastic, aluminum, and glass objects. Results showed that 1.5-4.0 hours after inoculation, S.dysenteriae type 1 became non-culturable, and after five days,non-culturable but viable S. dysenteriae type 1 could be detected by both PCR and fluorescent antibody techniques. Fomites can be considered an important potential route of transmission of VBNC S.dysenteriae type 1 and a significant factor in the epidemiology of shigellosis.