Environment and virulence factors of Vibrio cholerae strains isolated in Argentina : V. cholerae: environment and virulence

To determine the presence of Vibrio cholerae in different areas of Argentina in three sample types, to determine the composition of planktonic communities in areas at which this pathogen was detected and to characterize the virulence properties and antimicrobial resistance of the recovered environmental isolates.

Water and plankton samples were collected in marine, brackish and freshwater environments. Vibrio cholerae non-O1, non-O139 was isolated in 36.1% of the samples analysed. The micro-organism was detected in freshwater but not in marine or brackish samples. No relationship was found between isolation of V. cholerae and presence of any species of plankton.

All the isolates presented very similar virulence profiles by PCR, lacking ctxA and tcpA El Tor and containing hlyA (98.7%), rtxA (99.0%), toxR (98.7%) and stn-sto (1.9%). Resistance to ampicillin was found in both Tucumán (21%) and Buenos Aires isolates (45%). We identified two geographic areas in Argentina where V. cholerae was present: freshwaters of the rivers from Tucumán and the Río de la Plata.

The identification of V. cholerae strains in the environment, carrying both virulence factors and resistance to antimicrobial agents, highlight the need for a continuous and active surveillance of this pathogen.