OusB, a broad-specificity ABC-type transporter from Erwinia chrysanthemi, mediates uptake of glycine betaine and choline with a high affinity.

The ability of Erwinia chrysanthemi to cope with environments of elevated osmolality is due in part to the transport and accumulation of osmoprotectants. In this study we have identified a high-affinity glycine betaine and choline transport system in E. chrysanthemi.

Antibacterial activity of glycine betaine analogues: involvement of osmoporters.

Glycine betaine (GB) analogues were obtained using solid phase organic synthesis and assayed for their toxic activity against 15 Gram positive and Gram negative bacteria. Four benzyl derivatives of GB were selected to determine their effect on bacterial growth. Bacteriostatic and lethal effects were observed for compound 1 and compound 2, respectively.

Reduction of adhesion properties of Ruditapes philippinarum hemocytes exposed to Vibrio tapetis.

Vibrio tapetis is the causative agent of brown ring disease (BRD), which affects a species of clam, Ruditapes philippinarum. After incubation with V. tapetis, hemocytes lose filopods and become rounded, indicating cytotoxic activity of the bacterium.

Measurement of Crassostrea gigas hemocyte oxidative metabolism by flow cytometry and the inhibiting capacity of pathogenic vibrios.

A flow cytometric method to measure the production of oxidative metabolism products was adapted for use with Crassostrea gigas hemocytes. The method is based upon the oxidation, by hydrogen peroxide (H2O2), of intracellular 2',7'-dichlorofluorescin (DCFH) to green-fluorescent dichlorofluorescein. Activation of the respiratory burst (RB) was tested using phorbol myristate acetate with no success.

Effect of a mono-specific algal diet on immune functions in two bivalve species--Crassostrea gigas and Ruditapes philippinarum.

The impact of diets upon the fatty acid composition of haemocyte polar lipids and consequently upon immune parameters has been tested in the oyster Crassostrea gigas and the clam Ruditapes philippinarum. Oysters and clams were fed each of three cultured algae: Chaetoceros calcitrans, which is rich in 20:5(n-3) and 20:4(n-6) and poor in 22:6(n-3) fatty acids; T-Iso (Isochrysis sp.), which is rich in 22:6(n-3) and deficient in 20:5(n-3) and 20:4(n-6); and Tetraselmis suecica, which is deficient in 22:6(n-3) and contains only small amounts of 20:5(n-3) and 20:4(n-6).

Characterization of strains of Vibrio splendidus and V. tapetis isolated from corkwing wrasse Symphodus melops suffering vibriosis.

Two vibrio bacteria pathogenic to the corkwing wrasse Symphodus melops were isolated. Vibriosis-inducing strain LP1 was isolated as the dominanting bacterium in kidney samples of dead and moribund wrasse from a population suffering vibriosis and high daily mortality in 1998 on the Norwegian west coast. The other vibriosis-inducing strain, LP2, was isolated from wrasse captured the following year.