Free-Living and Plankton-Associated Vibrios: Assessment in Ballast Water, Harbor Areas, and Coastal Ecosystems in Brazil

Abstract

Ballast water (BW) is a major transport vector of exotic aquatic species and pathogenic microorganisms. The wide-ranging spread of toxigenic Vibrio cholerae O1 from harbor areas has been frequently ascribed to discharge of contaminated BW into eutrophic coastal environments, such as during the onset of the seventh cholera pandemic in South America in the early 1990s. To determine the microbiological hazards of BWs transported to Brazilian ports, we evaluated water and plankton samples taken from (i) BW tanks of recently arrived ships, (ii) port areas along the Brazilian coastline from ∼1 to 32°S and (iii) three coastal areas in São Paulo State. Vibrio concentration and toxigenic V. cholerae O1 occurrence were analyzed. Plankton-associated vibrios were more abundant than free-living vibrios in all studied environments. V. cholerae was found in 9.5% of ballast tanks and 24.2% of port samples, both as free-living and attached forms and, apart from the Santos harbor, was absent off São Paulo State. Toxigenic V. cholerae O1 isolates (ctxA+, tcpA+), involved in cholera disease, were found in BW (2%) and harbor (2%) samples. These results confirm that BW is an important carrier of pathogenic organisms, and that monitoring of vibrios and other plankton-attached bacteria is of paramount importance in BW management programs.

Population analysis of Vibrio parahaemolyticus originating from different geographical regions demonstrates a high genetic diversity

“…birds or ships’ ballast waters [43,44,48]. Then the strain (of a distinct ST) would evolve locally into a distinct STs still belonging to the same pST.…”

Failure of the public health testing program for ballast water treatment systems

“…For example, there is strong evidence that ballast water has introduced pandemic strains of both Vibrio cholerae and V. parahaemolyticus into new coastal regions (McCarthy and Khambaty, 1994;Quilici et al, 2005;Cabanillas-Beltran et al, 2006;Nair et al, 2007;Ansede-Bermejo et al, 2010;Rivera et al, 2013), and scientists at the Centers for Disease Control recently warned of the need to treat ballast water to prevent the spread of cholera from Haiti (Cohen et al, 2012). Several researchers (National Research Council, 1992;Epstein et al, 1993;McCarthy and Khambaty, 1994) and the Pan American Health Organization (Anderson, 1991) concluded that the 1991 cholera epidemic in South America, which resulted in over one million cases of cholera and 10,000 deaths (Tauxe et al, 1995), likely arrived from Asia in ballast water, though others have questioned this pathway (Martinez-Urtaza et al, 2008;Lam et al, 2010).…”

“…Ships' ballast water discharges can introduce bacterial pathogens and diseases into novel regions of the world (McCarthy and Khambaty, 1994;Dobbs and Rogerson, 2005;Cohen et al, 2012;Rivera et al, 2013). For example, there is strong evidence that ballast water has introduced pandemic strains of both Vibrio cholerae and V. parahaemolyticus into new coastal regions (McCarthy and Khambaty, 1994;Quilici et al, 2005;Cabanillas-Beltran et al, 2006;Nair et al, 2007;Ansede-Bermejo et al, 2010;Rivera et al, 2013), and scientists at the Centers for Disease Control recently warned of the need to treat ballast water to prevent the spread of cholera from Haiti (Cohen et al, 2012).…”

Live-Attenuated and Inactivated Whole-Cell Bacterial Vaccines

“…Vibrios "re-emerge" after years of seeming absence when a combination of favorable environmental conditions appears right. Attached to plankton that act as hosts for the dormant cholera organism, Vibrios can travel long distances either by hitchhiking with plankton on ocean currents across thousands of kilometers and over periods of months and years, or by means of ballast water of cargo ships crossing the world's oceans (Rivera et al 2012). Alternatively, it has been suggested that Vibrios can also travel through air as hitchhikers attached to the surface of adult nonbiting midges (observed mainly with Chironomus sp.)…”