Risk of Vibrio transmission linked to the consumption of crustaceans in coastal towns of Côte d'Ivoire.

The purpose of this study was to assess the risk of Vibrio spp. transmission from crustaceans to humans in two coastal towns of Côte d'Ivoire. Bacteriologic analysis was performed on 322 crustacean samples obtained from six markets in Abidjan and one in Dabou. Suspected Vibrio colonies were identified by morphological, cultural, biochemical, and molecular tests and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. PCR assays were used to further characterize Vibrio strains. A survey on consumption of crustaceans was conducted among 120 randomly selected households in Abidjan. Overall, Vibrio spp. were isolated from 7.8% of the crustacean samples studied, at levels as high as 6.3 log CFU/g. Of the Vibrio strains identified, 40% were V. alginolyticus, 36% were V. parahaemolyticus, and 24% were nontoxigenic V. cholerae; the latter two species can cause mild to severe forms of seafood-associated gastroenteritis. Among interviewed households, 11.7% reported daily consumption of crustaceans, confirming the high probability of exposure of human population to Vibrio spp., and 7.5% reported symptoms of food poisoning after consumption of crustaceans. The absence of genes encoding major virulence factors in the studied strains, i.e., cholera toxin (ctxA and ctxB) in V. cholerae and thermostable direct hemolysin (tdh) and thermostable direct hemolysin-related hemolysin (trh) in V. parahaemolyticus, does not exclude the possibility of exposure to pathogenic strains. However, human infections are not common because most households (96.7%) boil crustaceans, usually for at least 45 min (85.9% of households) before consumption.

Propionibacterium microaerophilum sp. nov., a microaerophilic bacterium isolated from olive mill wastewater.

A new gram-positive, facultative anaerobic, microaerophilic bacterium, designated strain M5T, was isolated from a decantation reservoir of olive mill wastewater. The cells were rod-shaped, non-motile, non-spore-forming and catalase-negative. Growth occurred at pH ranging from 4.5 to 9.5, with optimum growth at 7.0. The optimum temperature for growth was around 30 degrees C. Although growth occurred under anaerobic and aerobic conditions, the optimum O2 concentration for growth was determined as 5% in the gas phase of the culture. During anaerobic growth, glucose or lactate were mainly fermented to propionate, acetate and CO2. In the presence of O2 (more than 2%), glucose was oxidized completely to CO2. The G+C content of the DNA was 67.7+/-0.6 mol% and 16S rRNA gene analysis revealed that the new isolate belonged to the cluster of 'dairy' propionibacteria, Propionibacterium acidipropionici being its closest phylogenic relative (97.5% similarity). However, the level of DNA relatedness between strain M5T and P. acidipropionici was 56.2%. Consequently, both the phenotypic (range of substrates used) and genotypic characteristics of strain M5T allow it to be assigned as a new species of the genus Propionibacterium, Propionibacterium microaerophilum sp. nov. The type strain is strain M5T (= CNCM I-2360T = DSM 13435T).