Characteristics of the Turkish isolates of Francisella tularensis.

ABSTRACT

In this study, cultures of patients with tularemia were evaluated, and antimicrobial susceptibilities of two Francisella tularensis strains were tested by disk diffusion and E-test methods. A high-resolution multiple-locus variable-number tandem repeat analysis (MLVA) comprising six variable-number tandem repeat loci was applied to elucidate the genetic relatedness among Turkish and Bulgarian isolates which were isolated in a recent outbreak. The patients were diagnosed in two outbreaks in two cities of Turkey in 2005 and 2006. A total of 16 samples from 12 patients were cultured, and PCR tests were carried out on 15 samples that were positive in five lymph node aspirates and two soft tissue aspirates. F. tularensis was isolated from the lymph nodes of two patients. Aminoglycosides, quinolones, chloramphenicole, tetracyclines, nitrofurantoin, and rifampicin inhibited growth of the isolates. The Turkish isolates appeared to share a common MLVA pattern with one of the four Bulgarian outbreak genotypes.