Characterization of Francisella tularensis Strains, Comparing Their Carbon Source Utilization

• Published in: Zoonoses and public health Vol. 57; no. 6; pp. 417 - 422
• Main Authors: Gyuranecz, M, Erdélyi, K, Fodor, L, Jánosi, K, Szépe, B, Füleki, M, Szőke, I, Dénes, B, Makrai, L
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.09.2010; Blackwell Publishing Ltd
• Subjects: animal diseases; Animals; Bacteria; Biochemical characteristics; Biolog; Carbon - metabolism; carbon source; carbon sources; Cercopithecus aethiops; disease diagnosis; DNA Fingerprinting; Erythrocebus; Erythrocebus patas; Francisella tularensis; Francisella tularensis - classification; Francisella tularensis - genetics; Francisella tularensis - isolation & purification; Francisella tularensis - metabolism; Francisella tularensis subsp. holarctica; Genetics; glycerol; Hares - microbiology; Hungary; isolation; Lepus; Lepus europaeus; molecular sequence data; monkeys; Monkeys & apes; nucleotide sequences; polymerase chain reaction; Polymerase Chain Reaction - veterinary; Rabbits; RNA, Ribosomal, 16S - genetics; sequence analysis; Sequence Analysis, DNA; seroprevalence; Species Specificity; strains; Tularemia; Tularemia - diagnosis; Tularemia - microbiology; Tularemia - veterinary; Virulence - genetics; zoonosis; Hungary
• ISSN: 1863-1959; 1863-2378
• DOI: 10.1111/j.1863-2378.2009.01238.x

Thirteen Francisella tularensis strains were isolated from 22 seropositive brown hares (Lepus europaeus) originating from different parts of Hungary, and further two from a patas monkey (Erythrocebus patas) and vervet monkey (Chlorocebus aethiops). The isolates were identified as F. tularensis ssp. holarctica on the basis of culture, morphological and biochemical characteristics. The identification was verified by polymerase chain reaction and the sequencing of the partial 16S rRNA gene. Utilization of carbon sources of the 15 F. tularensis strains was characterized with the Biolog system. The system was able to identify the strains already after 4 h of incubation, not only after the standard 24 h. After the analysis and comparison of the metabolic profiles of our strains with the Biolog database, it was concluded that not all carbon sources indicated in the database were utilized by our isolates. The Biolog software fails to distinguish the highly virulent F. tularensis ssp. tularensis and the moderately virulent F. tularensis ssp. holarctica but the Biolog microplates can be manually read to differentiate the two subspecies based on glycerol source utilization. As all the studied strains were unable to use glycerol, they could be identified as F. tularensis ssp. holarctica. The dendrogram based on the metabolic relationship of the strains shows that the isolates are very similar to each other, which correlates with the conservative genetic character of F. tularensis ssp. holarctica.