The adherence to and invasion of cultured epithelial cells by Vibrio hollisae were examined by quantitative studies and by light, fluorescent, and electron microscopy. Condensed actin was observed around clustered adherent and intracellular bacteria. Bacteria multiplied intracellularly. Inhibitor studies indicated that internalization occurred by an integrated pleiotropic process involving eukaryotic and prokaryotic protein syntheses, microfilaments, microtubules, and receptor-mediated endocytosis.

Vibrio vulnificus, an opportunistic human pathogen, is found as member of the normal microflora of shellfish and other seafoods, many of which are eaten raw. Though usually not harmful,V. vulnificusis responsible for causing fulminating septicemia in immunocompromised individuals. In previous light microscopic studies, we showed data suggesting that isogenic unencapsulated phase variants were more adherent to HeLa cells than were counterpart encapsulated phase variants. In this study, we extended our observations by comparing phase variant capsular morphology stained with Alcian blue (AB) and Ruthenium red (RR), and investigated the dynamics of biofilm formation by these organisms to glass coverslips (CS) using quantitative plate counts and scanning electron microscopy (SEM).To characterize the morphology of capsules expressed by these organisms, we stained cells grown on trypticase soy agar containing 1 % NaCl (TSA/NaCl) with AB and then prepared them for electron microscopy (EM) according to the method described by Hendleyet al.

In 1986, an outbreak of diarrheal disease in Texas was attributed to contaminated iced tea in whichKlebsiella pneumoniaewas the predominant flora. Although the ten strains tested were of different serotypes, they all produced a heat labile enterotoxin. Some of these enterotoxigenic strains (ETKP) also exhibited mannose-resistant hemagglutinins, which were later found to be type 3 MR/K fimbriae. In this study we extended our observations and investigated fimbrial expression, as well as HeLa cell adherence behavior, using negative staining, immunogold labeling, and scanning electron microscopy (SEM).ETKP strains were grown on colonization factor antigen agar overnight at 37° C for expression of fimbriae. The presence of fimbriae and immunogold labeling of the cells was determined as described by Wolfeet al.Antiserum was prepared against purified fimbriae in rabbits and dilutions of primary and secondary antibodies (goat anti-rabbit IgG conjugated with 10 nm gold particles) in phosphate buffered saline, pH 7.2, containing 1 % bovine serum albumin and 0.5% Tween 20 were used to label cells.

Studies of bacterial behavior in many environments have shown that most organisms attach to surfaces, forming communities of microcolonies called biofilms. In contaminated medical devices, biofilms may serve both as reservoirs and as inocula for the initiation of infections. Recently, there has been much concern about the potential of dental units to transmit infections. Because the mechanisms of biofilm formation are ill-defined, we investigated the behavior and formation of a biofilm associated with tubing leading to the water syringe of a dental unit over a period of 1 month.