Environment and virulence factors of Vibrio cholerae strains isolated in Argentina

Abstract

Aims: 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. Methods and Results: 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%). Conclusions: We identified two geographic areas in Argentina where V. cholerae was present: freshwaters of the rivers from Tucumán and the Río de la Plata. Significance and Impact of the Study: 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.

Detection of ctx gene positive non-O1/non-O139 V. cholerae in shrimp aquaculture environments

“…Other virulence factors associated with V. cholerae are tcpA, hlyA, zot, ace, rtxA, etc. Fraga et al (2007) reported that V. cholerae isolates from the environment lacked ctxA and tcpA but contained hlyA (98·7%), rtxA (99·0%), toxR (98·7%) and stn-sto (1·9%) The present study did not search for other virulence genes and further studies on the prevalence of these genes in ctx positive non-O1/non-O139 would aid in risk assessment. The sensitivity of V. cholerae-duplex PCR was determined using templates prepared from different V. cholerae cell concentrations.…”

“…PCR methods that target a single gene/sequence, multiple genes within V. cholerae, or two or more pathogens in a single PCR assay have been used by several researchers (Brasher et al 1998;Bacteriological Analytical Manual 2001;Singh et al 2002;Jing et al 2003;Karunasagar et al 2003;Panicker et al 2004a;Fraga et al 2007;Tarr et al 2007;Khuntia et al 2008). Tarr et al (2007) developed a multiplex PCR for V. vulnificus, V. parahaemolyticus, V. mimicus and V. cholerae wherein the intra-specific variation in the conserved housekeeping gene viz., sodB was used as a source of marker for V. cholerae and as the house keeping genes are invariably present in all isolates this PCR method helps in the detection of all V. cholerae isolates irrespective of their toxigenic status.…”

Human Enteric Pathogens in Eight Rivers Used as Rural Household Drinking Water Sources in the Northern Region of South Africa

“…Nontoxic Vibrio spp. is widespread in water environments [49] and V. cholerae has been isolated from surface water [67,68] with the occurrence of V. cholerae in water sources that are linked to faecal pollution [69].…”

DETECTION OF VIRULENCE GENES IN ENVIRONMENTAL STRAINS OF Vibrio cholerae FROM ESTUARIES IN NORTHEASTERN BRAZIL

“…Nevertheless, despite the extensive research done over the past years on the ecology, pathogenicity and epidemiological behavior of the species, many questions remain unanswered 9,32 .…”