Pseudomonas (Burkholderia) pseudomallei in Thailand, 1964-1967: geographic distribution of the organism, attempts to identify cases of active infection, and presence of antibody in representative sera.

The purpose of this study, initiated in 1964 and concluded in 1967, was to define the distribution of Pseudomonas (now Burkholderia) pseudomallei in Thailand, to evaluate its importance as an etiologic agent, and to survey the presence of antibody in people that might indicate prior infection and/or contact with the microorganism.

Inhibitory effect of cytochalasins on the motility of rat epididymal spermatozoa in vitro.

Cytochalasins A, B, C, D and E at a concentration of 5.0 microgram/ml significantly inhibited the motility of spermatozoa collected from the cauda epididymidis of rats when diluted in Hank's solution containing BSA by 21.6-38.1% within a few min incubation. The motility was significantly inhibited (approx. 16.7%) by Cyto. E at a concentration as low as 1.0 microgram/ml within 30 min. This inhibitory effect of Cyto. E was a dose-dependent at the concentrations ranging from 1.0-20.0 microgram/ml. These findings demonstrate that cytochalasins are powerful inhibitors on the motility of rat epididymal spermatozoa.

Inhibitor to the cell-bound haemagglutinin of Vibrio cholerae.

An inhibitor to cell-bound HA was found to be produced at the non-haemagglutinating phase of the culture cycle by a classical vibrio strain which produced a cell-bound HA early and transiently during its growth. The HA-negative filtrate obtained from the late log-culture was found to inhibit the cell-bound HA activity produced by the same vibrio strain. It was also found to be produced early in shaking cultures at 37 degrees C and to mask the activity of early cell-bound HA in whole culture tests. This inhibitor is suggested to be responsible for the failure to obtain HA activity or adhesive vibrio cells grown at 37 degrees C and for the transient expression of cell-bound HA by some V. cholerae strains.

Characterization and distribution of the cell-bound haemagglutinins produced by Vibrio cholerae.

The two biotypes of Vibrio cholerae were found to produce two distinct cell-bound haemagglutinins (HAs). El Tor vibrios, most of their nonmotile mutants and nonpathogenic El Tor strains produced a mannose-sensitive cell-bound HA constitutively under all growth conditions examined. Some classical vibrios, their nonmotile mutants and antigenically rough mutants of classical strains produced a fucose-sensitive cell-bound HA continually. Other classical vibrios produced neither cell-bound HA nor a fucose-sensitive cell-bound HA transiently.