Genetic and phenotypic analysis of Vibrio cholerae non-O1, non-O139 isolated from German and Austrian patients

Eur J Clin Microbiol Infect Dis. 2014 May;33(5):767-78. doi: 10.1007/s10096-013-2011-9. Epub 2013 Nov 10.

Abstract

Vibrio cholerae belonging to the non-O1, non-O139 serogroups are present in the coastal waters of Germany and in some German and Austrian lakes. These bacteria can cause gastroenteritis and extraintestinal infections, and are transmitted through contaminated food and water. However, non-O1, non-O139 V. cholerae infections are rare in Germany. We studied 18 strains from German and Austrian patients with diarrhea or local infections for their virulence-associated genotype and phenotype to assess their potential for infectivity in anticipation of possible climatic changes that could enhance the transmission of these pathogens. The strains were examined for the presence of genes encoding cholera toxin and toxin-coregulated pilus (TCP), as well as other virulence-associated factors or markers, including hemolysins, repeats-in-toxin (RTX) toxins, Vibrio seventh pandemic islands VSP-1 and VSP-2, and the type III secretion system (TTSS). Phenotypic assays for hemolysin activity, serum resistance, and biofilm formation were also performed. A dendrogram generated by incorporating the results of these analyses revealed genetic differences of the strains correlating with their clinical origin. Non-O1, non-O139 strains from diarrheal patients possessed the TTSS and/or the multifunctional autoprocessing repeats-in-toxin (MARTX) toxin, which were not found in the strains from ear or wound infections. Routine matrix-assisted laser desorption/ionization (MALDI-TOF) mass spectrometry (MS) analysis of all strains provided reliable identification of the species but failed to differentiate between strains or clusters. The results of this study indicate the need for continued surveillance of V. cholerae non-O1, non-O139 in Germany, in view of the predicted increase in the prevalence of Vibrio spp. due to the rise in surface water temperatures.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Austria / epidemiology
  • Bacterial Typing Techniques
  • Cluster Analysis
  • Diarrhea / epidemiology*
  • Diarrhea / microbiology*
  • Genotype
  • Germany / epidemiology
  • Humans
  • Molecular Typing
  • Phenotype
  • Vibrio Infections / epidemiology*
  • Vibrio Infections / microbiology*
  • Vibrio cholerae / classification*
  • Vibrio cholerae / genetics
  • Vibrio cholerae / isolation & purification*
  • Vibrio cholerae / physiology
  • Virulence Factors / analysis
  • Virulence Factors / genetics

Substances

  • Virulence Factors