[Characterization of Shigella strains isolated in ankara, Turkey by antimicrobial resistance models, plasmid profile analysis and pulsed-field gel electrophoresis]. / Ankara'da Izole Edilen Shigella Kökenlerinin Antibiyotik Direnç Modelleri, Plazmid Profil Analizi ve Degisken Alanli Jel Elektroforezi ile Incelenmesi.

Shigella is one of the most important causative agents of diarrhea especially in childhood. Since man is the main reservoir of Shigella and human to human transmission is possible, Shigella can easily spread in public and cause outbreaks. In this study, a total of 60 Shigella strains isolated in Ankara, Turkey by years 2001, 2008 and 2009 were investigated by their antimicrobial susceptibility profiles, plasmid profile analysis (PPA) and pulsed-field gel electrophoresis (PFGE). For epidemiological investigation, the results obtained by antibiotic resistance typing (ART) which was the phenotyping method, was compared to the results of the genotyping methods which were PPA and PFGE. Of the isolates 49 (81.6%) were S.sonnei, 10 (16.6%) were S.flexneri and one was (1.6%) S.dysenteriae. Antimicrobial susceptibilities were evaluated by disc diffusion method and the highest resistance rates were found against trimethoprim/sulfamethoxazole (91.6%), followed by tetracycline (68.3%) and ampicillin (26.6%). Resistance against ampicillin, chloramphenicol and amoxycillin/clavulanic acid were found higher in S.flexneri isolates than S.sonnei (p< 0.001). All isolates were found to be susceptible to ciprofloxacin, gentamicin and ceftazidime. S.sonnei demonstrated 12 and S.flexneri demonstrated 4 antibiotic resistance models. All isolates were carrying plasmids with varying sizes and varying numbers between 1 to 7. S.sonnei isolates demonstrated 27 and S.flexneri isolates demonstrated 8 plasmid profiles. S.sonnei isolates were clustered in 4 patterns and S.flexneri were clustered in 5 patterns by PFGE. This method demonstrated obvious clonal similarity among S.sonnei strains isolated in Ankara and discriminative power (DP) was calculated as 0.26. PPA and ART demonstrated higher DP among S.sonnei strains (0.97 and 0.75, respectively). In this study gain or loss of instable genetic mobile elements were thought to be responsible for higher discriminative powers of PPA and ART methods. These typing methods were found to be appropriate for the epidemiological investigation of strains collected in a short time period. PFGE was found to be convenient for the evaluation of clonal relatedness of the strains, however, in such geographical areas where the same clone was in circulation, use of ART and/or PPA together with PFGE would be useful for precise discrimination of Shigella strains.

[Phenotypic and genotypic traits of vancomycin-resistant enterococci in a public hospital: the first vanB-positive Enterococcus faecium isolates]. / Bir Devlet Hastanesinde Vankomisine Dirençli Enterokok Suslarinin Fenotipik ve Genotipik Olarak Degerlendirilmesi: Ilk vanB-Pozitif Enterococcus faecium Izolatlari

Thirty eight vancomycin resistant enterococci (VRE) were isolated in one year surveillance study for hospital infection control programme in a state hospital in Ankara, Turkey. All isolates were identified as Enterococcus faecium by VITEK2 system (bioMerieux, France). Vancomycin and teicoplanin resistant 30 strains were defined as vanA phenotype while vancomycin-resistant teicoplanin-susceptible eight strains were defined as vanB phenotype. vanA genes were found in 30 strains while vanB genes were found in five strains by using PCR method. Those five strains were the first vanB positive E.faecium strains in our country. VRE strains revealed six different band patterns by PFGE, while six isolates could not be classified. All isolates with vanB type resistance were found in the same cluster. Source of vanB positive strains was considered as the hemodialysis unit. When the previous national reports related to vancomycin-resistant enterococci were considered, this was the first report of vanB positive E.faecium isolates in our country. This emphasized that both the diversity of VRE and the isolation rate was increasing. In order to eliminate the spread of VRE, effective surveillance studies should be performed and protective measures should be established promptly.