Aims: This study was carried out to investigate the occurrence of potentially pathogenic species of Vibrio in French marine and estuarine environments. Methods and Results: Samples of coastal waters and mussels collected between July and September 1999 were analysed by culture, using selective media including thiosulphate-citratebile salts-sucrose and modified cellobiose-polymixin B-colistin agar. Presumptive Vibrio colonies were isolated and identified using selected biochemical tests. Specific primers based on flanking sequences of the cytolysin, vvhA gene, pR72H DNA fragment and 16S-23S rRNA intergenic spacer region (ISR) were used in a polymerase chain reaction (PCR) to confirm the identification of Vibrio vulnificus, V. parahaemolyticus and V. cholerae, respectively. In this study, V. alginolyticus (99 of 189) was the predominant species, followed by V. parahaemolyticus (41 of 189), V. vulnificus (20 of 189) and non-O1/non-O139 V. cholerae (three of 189). All 20 V. vulnificus isolates showed PCR amplification of the vvhA gene, 16 of which had been isolated from estuarine water. The PCR amplification of the pR72H DNA fragment in 41 V. parahaemolyticus isolates generated two unique amplicons of 387 and 320 bp. The latter, present in 24AE4% of these isolates, had not previously been found in V. parahaemolyticus strains examined to date. Amplification of the trh gene in two of the isolates suggested these to be virulent strains. Three strains identified as V. cholerae by amplification of the 16S-23S rRNA ISR were confirmed to be non-cholera (non-O1/non-O139) strains. Conclusions:The results of this study demonstrated the presence of pathogenic Vibrio species in French coastal waters. Furthermore, the PCR approach proved useful for the rapid and reliable confirmation of species identification. Significance and Impact of the Study: These findings indicate the potential sanitary risk associated with the presence of pathogenic Vibrio spp. in cultivated mussels and in the aquatic environment. The PCR can be used to detect pathogenic vibrios directly in environmental samples.

Staphylococcal skin colonization is a common feature of atopic dermatitis (AD) in adults. Little is known about prevalence and persistence of staphylococci in children. Forty-one AD children (mean age, 70 months) and 41 age-matched controls were studied. S. aureus was isolated from 38 AD patients (93%; 32% of controls, P less than .001) and 37% of AD patients (5% of controls, P less than .001) harbored toxigenic (enterotoxins, toxic shock syndrome toxin) S. aureus strains. No individual biotype prevailed. On follow-up (mean interval, 9 months), 70% of S. aureus strains were reisolated. Nasal and cutaneous S. aureus strains were identical in 73% of AD patients (7% of controls, P less than .001), reflecting increased self-contamination. Identical staphylococcal strains in AD children and their mothers were observed in 38% (S. aureus) and 16% (coagulase-negative strains; P less than .001). The prevalence of staphylococcal colonization in AD children is comparable to that in adults. High rates of self-contamination, transmission to contacts, and prevalence of toxigenic strains in AD children may have clinical and epidemiologic implications.

Synthetic antigens that mimic the terminal hexasaccharide epitope of the O-specific polysaccharide of Vibrio cholerae O1, serotype Ogawa, were conjugated to bovine serum albumin (BSA). Conjugates with carbohydrate-to-carrier molar ratios of 15.5:1, 9.2:1, and 4.6:1 were tested for immunogenicity and efficacy in mice. The role of preimmunity to BSA and the use of adjuvant in the generation of the serologic response to the O-specific polysaccharide and protection against virulent V. cholerae was examined. Preimmunity to BSA did not affect the anti-Ogawa titers but seemed to enhance the protective capacity of antiserum. All 3 conjugates were immunogenic, but adjuvant was effective at inducing higher and earlier antibody responses. In tertiary serum samples, a correlation was found between vibriocidal activity and protection. The protective capacity of antiserum was evident in serum from mice immunized with all conjugates, but it was highest in the groups that received the conjugate with the lowest level of substitution. Further studies are required to increase understanding of the reason for differential protection.

The adherence of Staphylococcus aureus to human endothelial cells (EC) is probably an important step in the pathogenesis of systemic staphylococcal infections. We examined the influence of type 5 capsular polysaccharide (CP5) production, the global regulator agr, and the bacterial growth phase on S. aureus adherence to EC. Whereas S. aureus Newman showed maximal adherence to EC in the logarithmic phase of growth, an isogenic agr mutant showed maximal adherence in the stationary growth phase. S. aureus adherence to EC and CP5 expression were negatively correlated: a mutation in the agr locus diminished CP5 production and led to increased adherence. Likewise, induction of CP5 expression by addition of NaCl to the growth medium resulted in reduced staphylococcal adherence to EC. S. aureus Newman cells that adhered to EC did not express CP5. A Newman cap5O mutant was acapsular and showed significantly greater adherence to EC than the parental strain did (P < 0.005). Complementation of the cap5O mutation in trans restored CP5 expression and reduced EC adherence to a level similar to that of the parental strain. The enhanced adherence shown by the cap5O mutant was similar in magnitude to that of the agr mutant or the cap5O agr double mutant. Cells of the cap5O mutant and cap5O agr double mutant harvested from stationary-phase cultures adhered significantly better than did cells harvested in the exponential growth phase. These data are consistent with the postexponential and agr-independent expression by S. aureus of at least one putative EC adhesin, whose binding domain may be masked by CP5.Staphylococcus aureus is responsible for a broad range of human diseases, including foreign body infections, bacteremia, abscesses, and wound infections (41). The ability of S. aureus to adhere to extracellular matrix proteins is thought to be essential for colonization and the establishment of infections (17, 41, 52). The interaction of S. aureus with endothelial cells (EC) may play a major role in the pathogenesis of endovascular infections, including endocarditis and metastatic infections (26,41).S. aureus can express several cell wall-associated adhesins specific for recognizing matrix proteins; these adhesins are referred to as MSCRAMMs (microbial surface components recognizing adhesive matrix molecules) (52). MSCRAMMs with specific binding activity toward fibronectin (31, 62), fibrinogen (45, 47), and collagen (53) have been cloned and biochemically characterized. Whether MSCRAMMs are also responsible for the adherence of S. aureus to host cells is still unclear. A role for fibronectin-binding proteins in staphylococcal adherence to bovine epithelial cells (13) and mammary gland cells (36) was recently described; however, other factors were also postulated to mediate epithelial cell adherence (13).The expression of most cell wall adhesins and extracellular virulence determinants in S. aureus is coordinately regulated during the growth cycle (57). Some of the growth cycle-dependent expression patterns can be attributed to the ...

A method is described for typing Staphylococcus aureus capsular polysaccharides that is based on direct bacterial cell agglutination and immunoprecipitation of cell extracts with monospecific antisera. Encapsulated strains were identified by their inagglutinability with teichoic acid antisera. The typing sera reacted specifically with extracts of eight prototype strains.