Category: S

Family within the order Pseudomonadales, and consisting of rigid Gram-negative curved or spiral rods, usually motile. Often water¬ borne; some pathogenic to man and animals, including the Spirillum and Vibrio genera.  

Anaerobic, pleomorphic Gram-negative rods with characteristics so close to the Bacteroides genus that they are now commonly included under that heading.  

Classical test for demonstrating beta haemolysis in streptococcal culture. Serum broth cultures are incubated with washed horse or ox cells for 1 hour, haemolysis resulting if streptolysin ‘S’ is present.  

Solid medium dispensed in tubes or bottles which are sloped before the medium sets, giving a thin layer at the top of the container, and thickening progressively down to the base. The surface thus presented is suitable for inoculation by wire loop, swab or similar means.  

Mechanism facilitating the bacteriological examination (especially count of organisms) of air, measured volumes being directed through a slit on to the surface of a revolving agar plate. The machine may include a timing device to allow sampling at predetermined intervals.  

Polysaccharide (occasionally polypeptide) outermost layer of bacteria, covering the cell wall. Capsules are a thickened version of the slime layer. A trichrome is a sheath of slime covering a group of bacteria in linear formation.  

Agglutination tests (often of a preliminary nature) employing neat sera and saline emulsions of bacteria from colonies on solid media.  

Filters of fused ground glass particles, the finest of which retains bacteria.  

Mixture of bromthymol blue, cresol red, and thymol blue in alkali, used in bacteriology (e.g., Kohn’s medium).  

Addition of the inoculum to cooling molten agar or gelatin, which is then shaken, poured into Petri dishes, or left to set in the original tube to provide anaerobic conditions in the deeper portion.