Surveillance of Francisella tularensis in surface water of Kurdistan province, west of Iran

•Isolation of F. tularensis from surface water specifies the disease cycle in the environment and help us to control the disease in the endemic areas.•Isolation of F. tularensis from surface water is associated with a very low success rate and depends on various environmental parameters.•Many considerations should be addressed to improve the chance of isolation of F. tularensis from environmental samples. The etiologic agent of tularemia, Francisella tularensis, is transmitted to humans via ingestion of contaminated water or food, arthropods bite, respiratory aerosols, or direct contact with infected animals body fluids or tissues. In the current study, due to the importance of water in transmitting the disease and the report of the disease in different regions of Iran, surface water of Kurdistan province were evaluated for the presence of F.tularensis. Sampling was carried out in five-counties of Kurdistan province. Sixty-six specimens of surface water were collected. The detection was carried out by targeting ISFtu2 and fopA genes using TaqMan real-time PCR. Moreover, the samples were both cultured and inoculated into NMRI inbreed mice. Spleens of inoculated mice and bacterial isolates were tested by TaqMan real-time PCR. Despite the lack of isolation of F. tularensis, the results of the molecular testing indicate the presence of bacteria in surface water. Molecular positivity of one sample (1.51%) was confirmed using a real-time PCR for both ISFtu2 and fopA genes. Moreover, 4.54% of the samples were positive for ISFtu2. Since the in vitro isolation of bacteria from environmental samples is associated with a very low success rate and depends on various environmental parameters, the use of molecular techniques for monitoring of the bacteria in the contaminated areas is fully recommended.