Virulence factors and pathogenicity of Vibrio vulnificus strains isolated from seafood

Abstract

M . L . G A RC IA M OR EN O AN D M . LA ND G RA F. 1998. The virulence factors of Vibrio vulnificusare not yet well understood. So far, many hydrolytic enzymes have been implicated in the pathogenesis of this micro-organism. The present research was carried out in order to study the presence of some of these enzymes in 133 V. vulnificus strains isolated from 45 seafood samples. The results showed that 100% of these strains were positive for the production of lecithinase and lipase (Tween-80), 99·2% for caseinolytic protease, 96·9% for DNase, 65·4% for mucinase and 46·6% for elastase. None of the strains was positive for the production of collagenase and 96% were haemolytic against sheep blood cells. In relation to colony morphology on brain heart infusion (BHI) agar and nutrient agar, 59·4% of strains showed opaque morphology on BHI agar and 57·9% on nutrient agar, 10·5% presented translucent morphology on both agars and 30·1 and 31·6% of strains showed a mixture of opaque and translucent morphology on BHI agar and nutrient agar, respectively. None of the translucent colonies was virulent to mice. Therefore, opacity was a useful marker for potential virulence. Of 45 food samples contaminated with V. vulnificus, 29 (64·4%) presented strains lethal to adult mice.

Genotype Is Correlated with but Does Not Predict Virulence of Vibrio vulnificus Biotype 1 in Subcutaneously Inoculated, Iron Dextran-Treated Mice

“…Furthermore, many people experi- (1,15,43,(52)(53)(54)58). Therefore, there has been a significant amount of work devoted to identifying phenotypic and genotypic markers that could predict the virulence potential of different V. vulnificus strains, and certain genotypes are found significantly more frequently in clinical or environmental strains than would be predicted by chance.…”

Vibrio vulnificus: An Environmental and Clinical Burden

“…Prompt treatment with appropriate antibiotics is essential for optimal patient outcomes, particularly in more severe manifestations such as systemic septicaemia and wound infections (Krovacek et al, 1994; Moreno and Landgraf, 1998). Regardless of the route of infection, V. vulnificus infection responds positively to antibiotics and it has been clearly demonstrated that the greater the delay in the initiation of treatment, the higher the fatality rate (Rodrigues et al, 1992; Amaro et al, 1994; Krovacek et al, 1994; Moreno and Landgraf, 1998).…”

Extracellular hydrolytic enzyme screening of culturable heterotrophic bacteria from deep-sea sediments of the Southern Okinawa Trough

“…The bacterial extracellular amylases, acidic (pH 5.0) and neutral (pH 7.0) proteases, lipases and chitinases were screened using 2216 marine agar plates supplemented with 0.5% (w/v) soluble starch (Sangon, China) (Sánchez-Porro et al 2003), 2% (w/v) sterile skim milk (Oxoid, UK) (Zhang and Austin 2000), 1% (v/v) Tween 80 (polyoxyethylene sorbitan mono-oleate) (Sigma, USA) and 1% (w/v) arabic gum powder (Sigma, USA) (Moreno and Landgraf 1998), and 1% (w/v) arabic gum powder and 13-14% (wet weight) colloidal chitin prepared by the method of Gómez Ramírez et al (2004) and Rojas-Avelizapa et al (1999), respectively. The extracellular alkaline proteases were screened by LB agar plates adjusted to pH 10.0 and 3% NaCl salinity.…”