SUMMARYA comparative study of many strains of Pseudom,onas pseudomallei and Bacillus mallei has shown that these two species are very similar with respect to their nutritional and biochemical properties, thus confirming earlier claims of a relationship between them, based on such criteria as pathological and serological properties. P. pseudomallei is in all respects a typical and nutritionally highly versatile member of the genus Pseudomonas. In view of this fact we propose that B. mallei should also be placed in the genus Pseudomonas, even though it is a permanently non-motile bacterium. The ecology and possible evolutionary relationships between the two species are discussed in the light of the present findings.

Sugarbeet (Beta vulgaris) seeds which had undergone an advancement treatment germinated more quickly and showed greater germination in a standard test at 9°C than seeds which had been steeped in water. Both treatments included the fungicide, thiram (tetramethyl thiuram disulphide). Advanced seeds also emerged more quickly and showed higher establishment in the field. The levels of extractable high molecular weight (HMW) RNA and DNA from advanced, thiram-steeped and untreated seeds were compared. Advanced seeds contained significantly (P > 0.05) more HMW RNA and DNA than thiram-steeped or untreated seeds. Extractable DNA levels were higher from thiram-steeped seeds than untreated seeds but not significantly so. Cell-cycle studies on advanced seeds demonstrated an increase from 2% to 24% of root-tip nuclei with DNA contents of 4C and above. This indicates that DNA replication occurred during the advancement treatment. There was no evidence of cell division occurring, indicating that: (1) advanced seeds were arrested post-S-phase and (2) the period following DNA synthesis in sugarbeet seeds is desiccation tolerant.

illthough recent studies have demonstrated the mutational character of dissociation (1) and the selective role of metabolites on population changes in synthetic broth cultures of brucellae( 2.3) information on population changes in infected animals is fragmentary. Most investigations on the establishment of colonial variants in animal tissues have been with animals inoculated with variants isolated from stock cultures either alone or in combination with smooth (S) brucellae(4-7). These experiments demonstrated a selective advantage of the S type over variants manifested in all host species but to a lesser extent in those which have a relatively high order of natural resistance to infection with brucellae (8). The ability of mutants with decreased pathogenicity to persist in normally resistant hosts is paralleled by the ability of relatively apathogenic mutants of a variety of pathogens to establish themselves in immunized and carrier hosts( 9.10). Controlled observations of the establishment of variant organisms in tissues of animals inoculated with S brucellae alone have not been made. although Huddleson ( 1 1 ) has described the isolation of smooth-intermediate (SI) , rough ( R ) and mucoid (31) types of BruceZZa abortus from fetuses aborted by naturally infected cows. SI types were also isolated from the milk of naturally infected cows. Buddle and Boyes (12) investigated the properties of a nonsmooth organism isolated from cases of genital infection of sheep in Xew Zealand and suggest that it is a stabilized mutant or variety of Br. meZitensis. Braun et a L ( 7 ) recovered intermediate (I) types from guinea pigs inoculated with S and 31 organisms. The observations reported here were made to determine the fate of colonial variants arising during the course of experimental infections initiated with S cultures of Br. abortus ___ ~~~ * Published with -4pproval of the Director of the Wis. Agric. Exper. Station. Paper Xo. NS-170.and BI. suis in guinea pigs.S trep tompc in resist ant cultures of Br. abortus, strain 2308. and Br. suis, strain B, were used. Groups of 28 male guinea pigs each were inoculated intraperitoneally with lo3 cells of Br. suis or 3.5 ?I lo6 cells of Br. abortus. Replicate platings of heavy suspensions from which inocula were prepared were examined by the methods of Henry (4) and White and Wilson ( 13 ) : only S colonies were observed. Two animals from each group were sacrificed at intervals from 2 to 24 weeks after inoculation. The following organs were macerated and cultured on 2-1 agar(4) and 2-1 agar containing 500 pg streptomycin/ml : different lymph nodes, liver, spleen: testes, kidneys, and femoral bone marrow. Abscesses which developed were cultured separately. The colonial morphology of all isolates was determined by direct observation, the crystal violet and the acriflavine spot tests. Questionable colonies were picked and streaked on fresh plates for further examination. Observations were made of the colonial morphology of brucellae isolated from bovine material. Tissues and fluids f...

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A lipoid of low molecular weight, isolated from the supernatant fluid of cultures of Pseudomonas pseudomallei, killed mice, but not rabbits, in doses comparable to those of the homologous lipopolysaccharide and also lysed sheep erythrocytes. In rabbits this lipoid failed to elicit primary dermal lesions, to prepare the skin for the local Schwartzman reaction, or to induce antibody formation.