Occurrence and virulence properties of Vibrio and Salinivibrio isolates from tropical lagoons of the southern Caribbean Sea.

The Vibrionaceae are Gram-negative bacteria present in marine and estuarine environments worldwide, including several species known as important pathogens to humans and aquatic organisms. The aim of this research was to investigate the occurrence and virulence properties of Vibrio and Salinivibrio isolated from lagoons at Cuare Wildlife Refuge and Margarita Island in the southern Caribbean Sea. Water, plankton and oyster samples were collected during October 2011 and March 2012 and examined by specific PCR and culture methods. Vibrio genus DNA was detected in 95% of samples, while the intergenic spacer region (ISR) of Vibrio cholerae and the genes that code for the thermolabile direct haemolysin (tl) of Vibrio parahaemolyticus and the haemolysin/cytolysin (vvhA) of Vibrio vulnificus were absent or amplified in low proportions (23, 5, and 0%, respectively). Nine isolates from water and plankton were confirmed as Vibrio or Salinivibrio by phenotypic tests, 16S rRNA gene sequencing and phylogenetic analysis. All the isolates presented similar patterns of virulence factors, in which the genes ctxA (encoding for cholera toxin), tl and vvhA were lacking, whereas seven isolates displayed antibiotic resistance against ampicillin and cephalosporins. The 16S rRNA phylogenetic analysis showed the clustering of Vibrio isolates in three main clades: the plankton isolate from Cuare Wildlife Refuge formed a group with V. cholerae and Vibrio mimicus while the Margarita isolates clustered with sequences from the harveyi clade and Salinivibrio. This is the first time that Salinivibrio species are reported in tropical lagoons of the Caribbean Sea with antibiotic resistance.

Prevalence and Distribution of Vibrio spp. in Wild Aquatic Birds of the Southern Caribbean Sea, Venezuela, 2011-12.

Vibrio spp. are associated with waterbirds mainly in temperate latitudes. We evaluated the prevalence and distribution of Vibrio spp. from fecal samples of resident and migratory aquatic birds collected during October 2011 and March 2012 at two coastal sites in the tropical southern Caribbean Sea. We amplified DNA by PCR in 40% of samples, resulting in 47% and 36% estimated prevalence for resident and migratory birds in Cuare Wildlife Refuge, and 33% and 44% in Margarita Island, respectively. We found nontoxigenic Vibrio cholerae in Cuare Wildlife Refuge with a higher prevalence in resident birds (18%). Our PCR results for Vibrio and V. cholerae were not significantly different between sites or bird migratory status. The 16S rRNA phylogenetic analysis sequences from fecal samples from Cuare Wildlife Refuge were highly similar to V. cholerae and Vibrio vulnificus , whereas sequences from Margarita Island samples formed clusters with species related to the Harveyi clade. Our findings indicate that several species of Vibrio are common in aquatic birds along the southern Caribbean Sea and contribute to our understanding of the role of birds as possible reservoirs of potentially pathogenic bacteria.

Inventario y estudio comunitario de los mamiferos del parque nacional canaima, con una lista de las especies registradas para la Guayana venezolana / Communitary study and inventory of mammals in canaima national park, with a list of recorded species for the venezuelan Guiana region

Las comunidades de mamiferos del Parque Nacional Canaima son evaluados en términos de sus composiciones taxonómicos, estructuras trópicas y sensibilidades potenciales. El análisis abarca seis unidades ecológicas: bosques de tierras bajas bosques montañosos, arbustales, sabanas, herbazales subpuyanos y vegetación altotepuyana. Adicionalmente, se actualiza la lista de los mamiferos conocidos en la Guayana Venezolana, la cual incluye 236 especies (75 por ciento de las tazas registradas en el país); de ellas, 62 poseen distribuciones registradas a esta región y seis son endémicas. Dentro del área de influencia del Parque Nacional Canaima se estima existencia de al menos 210 especies, de las cuales 118 cuentan con registros y 92 son de presencia probable. En este parque nacional los bosques bajos y montañosos contienen las comunidades más diversificadas a nivel toxonómico y trópico. En ellas predominan especies de los órdenes Chiroptera, Rodentia, Carnivora y Marsupialia, la mayoría con estrategias alimentarias que incluyen la insectivoría, la frugivoría o la omnivoría. Las sabanas, los herbazales subtepuyanos y la vegetación altotepuyana poseen comunidades más simplificadas. Los órdenes dominantes son Chiroptera, Rodentia, representados principalmente por especies herbívoras, insectívoras u omnívoras. Las máximas sensibilidades fueron estimadas para las comunidades que habitan las cumbres tepuyanas, mientras que las sabanas y los herbazales subtepuyanos muestran los valores mínimos. Se discuten algunos aspectos relacionados con la conservación de los mamiferos de la Guayana Venezolana