The prevalence of Francisella spp. in different natural surface water samples collected from northwest of Iran

BACKGROUND AND OBJECTIVES: Francisella tularensis has a wide distribution in northern hemisphere of the world. Up to now, there was little information about the Francisella spp. situation in the environmental samples in Iran. In this study we aimed to determine the prevalence of Francisella spp. in the environmental samples in northwest of Iran. MATERIALS AND METHODS: A total of 237 natural water samples from ponds, rivers, lakes, springs and other surface waters from north western provinces of Iran (Kurdistan and Western Azerbaijan) were collected from September to November 2015. All samples were cultured for Francisella and other bacterial species and Real Time TaqMan PCR was performed on the concentrated and DNA extracted samples. For detection of the presence of bacterial DNA in the samples, two different targets in the genome of Francisella, ISFtu2 and fopA were used. RESULTS: Among the tested surface water samples, 40 (17.09%; 95% CI: 12.67–22.33%) and 12 (5.13%; 95%CI: 2.81–8.56%) samples were positive for ISFtu2 and fopA respectively. None of them was positive in culture. CONCLUSION: The prevalence of Francisella spp. in the environmental samples in the west of Iran is high and it is comparable with Turkey, Iran's neighboring country. Use of higher copy number genes or IS like ISFtu2 could improve the detection of this organism in the environmental samples.