Author/Editor		Glinšek Biškup, Urška; Kogoj, Rok; Korva, Miša; Knap, Nataša; Cerar Kišek, Tjaša; Knapič, Tea; Petrovec, Miroslav; Avšič-Županc, Tatjana
Title		Characterization of tularemia cases in Slovenia with multiple-locus variable-number tandem repeat analysis
Type		članek
Publication year		2021
Volume		str. str.
ISSN		1530-3667 - Vector borne and zoonotic diseases (Larchmont, N.Y.)
Language		eng
Abstract		Francisella tularensisis the etiologic agent of tularemia, a bacterial zoonotic disease. The genome ofF. tularensisshows a recent evolutionary change, especially in reservoirs. Variable number of tandem repeats(VNTR) is described as a high-speed molecular clock and can thus be used as a high-resolution typing system.The main objective of our study was to investigate the molecular diversity ofF. tularensisstrains and revealpossible sources of infection. Using real-time PCR targeting the ISFtu2 region, we successfully amplifiedtargeted DNA in 13/31 Slovenian patients with a clinical diagnosis of tularemia, and with PCR targeting thefopAgene, we obtained 11/13 PCR products. Sequencing revealed that all samples were identified asF. tularensissubsp.holarctica. We successfully obtained oneF. tularensisisolate from a lymph node aspirateby culture on chocolate agar. Our isolate was clustered into major clade B12 (subclade B43). We optimizedVNTR typing to be used directly on clinical samples. Multiple-locus VNTR analysis ( MLVA) revealed fiveunique MLVA types; 45.5% samples had the same MLVA type, another 27.3% shared a different MLVA type,and each of the remaining had a unique MLVA type. Most samples differed at only two VNTR markers (Ft-M03 and Ft-M06). Additionally, we investigated samples from small mammals (n=532) andIxodes ricinusticks (n=232) captured in the same geographical area in which patients with tularemia were found. NoF. tularensisDNA was detected in samples of small mammals orI. ricinusticks. The diversity of MLVA typesin Slovenia was high, despite the small region, but most of the samples from the same region shared the sameMLVA type. Our results suggest that MLVA is a useful tool for quick molecular characterization ofF. tularensisdirectly from patient samples, especially when investigating geographically localized outbreaks.
Keywords		tularemija klinični primeri Slovenija tularemia clinical cases Slovenia