Characterization of Vibrio cholerae isolated from the aquatic basins of the State of Pernambuco, Brazil

Abstract

Through a continuous bacteriological monitoring programme carried out by the Health Secretariat of the State of Pernambuco, Brazil, two isolates of Vibrio cholerae O1 El Tor Ogawa were discovered in an endemic area in 2001, during a cholera inactive period, along with six V. cholerae non-O1/non-O139 strains and two Aeromonas veronii biovar sobria strains showing an unusual characteristic of agglutination with O1 antiserum. Between that time and 2005, eight other O1 isolates were found. The virulence genes present in the V. cholerae differed among strains, with only three O1 strains harboring the ctxA gene. The O1 and some non-O1/non-O139 strains displayed identical patterns of amplification of the 16S-23S intergenic spacer region. RAPD of the 10 V. cholerae O1 strains, with the two primers used, revealed heterogeneity. The presence of V. cholerae carrying virulence genes in the aquatic basins examined confirms that they constitute a vibrio reservoir during a cholera inactive period, thus strengthening the argument for a continuous monitoring programme and preventative measures for cholera, mainly in the areas where the supply of drinking water is deficient.

Population and Genetic Study of Vibrio cholerae from the Amazon Environment Confirms that the WASA-1 Prophage Is the Main Marker of the Epidemic Strain that Circulated in the Region

“…In contrast to the environmental O1s from the Amazon, all of these strains were positive for ctxA , zot , and tcp . Significant diversity was found among the CTXφ genes and tcpA in a more recent study of environmental O1 isolates from the aquatic basin of state of Pernambuco [54]. O1 strains with partial sets of CTXφ genes with and without tcpA were identified, similar to what we found among the environmental O1 isolates from the Amazon.…”

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

“…Many cases of diarrhoeal diseases related to non-O1 and non-O139 V. cholerae were reported 2,7,21,26 . In addition, environmental strains of V. cholerae may cause outbreaks in the future 1,29 , possibly triggered by environmental changes, or by lateral or horizontal transference of virulence genes mediated by phages, pathogenicity is lets and/or other mobile genetic elements encoding cholera toxin 20,34 , as previously reported for marine populations of V. cholerae and V. parahaemolyticus 22 .…”

“…20 from four rivers in Pernambuco (northeastern Brazil), strains of non-O1 and non-O139 V. cholerae tested negative for ctxA , zot and ace , and only one strain was positive for tcpA . In contrast, THEOPHILO et al 34 assessed the distribution of virulence markers in Brazilian clinical and environmental strains of non-O1 and non-O139 V. cholerae isolated between 1991 and 2000 and found one of two environmental samples to be positive for ctx , while zot , ace and tcp were detected in clinical and environmental samples.…”

Environmental reservoirs and mechanisms of persistence of Vibrio cholerae

“…Referenced studies here are only a small fraction of the studies published for certain areas and should guide as an example. North – and Middle America: (Colwell et al, 1981; Ogg et al, 1989; Blackwell and Oliver, 2008; Lizárraga-Partida et al, 2009; Hill et al, 2011; Dickinson et al, 2013), South America: (Franco et al, 1997; Lipp et al, 2003; Leal et al, 2008; Martinelli Filho et al, 2010; Sá et al, 2012); Africa: (Taviani et al, 2008); Europe: (Andersson and Ekdahl, 2006; Covazzi Harriague et al, 2008; Kirschner et al, 2008; Vezzulli et al, 2009, Vezzulli et al, 2011; Böer et al, 2013; Cantet et al, 2013; Tall et al, 2013); Middle East: (Bakhshi et al, 2009; Grim et al, 2010; Gurbanov et al, 2011; Rashid et al, 2013); Asia Pacific: (Islam et al, 1994, 2013; Desmarchelier et al, 1995; Miyagi et al, 2003; Alam et al, 2006; Vimala et al, 2010; de Magny et al, 2011; Singh et al, 2012). …”