SPIRILLUM

(Lat.), n. n. Spi2r(sperVi3l'lum(lu4m). Dim. of spira, a coil. A coiled bacillus; a distinct genus of Schizomycetes in some cla ifications. Some authors include in S. only the spirally twisted threads in which the coils are rigid and few in number, 'giving the name Spirochcete to those in which the coils are numerous and not rigid, [a, 35.] Cf. VIBRIO. Cheese s. See S. tyrogenum. S. a my life rum. A species living in the syrup of beetroot sugar and giving rise to brisk fermentation. [A, 396 (a, 21).] S. attenuatum. A species of varying length, having three convolutions; found in sea-water. [A, 396 (a. 21).] S. cholerw:isiat ii-ii-. Fr., bacille-viryule chplerigene. Ger., Kommabacillus. The comma bacillus (see Plate iii, Fig. 16); a species regarded as the causal agent of Asiatic cholera on account of its constant presence in that disease and its absence in other diseases and in health. It is found in the dejecta and intestinal contents, and, according to Nicati and Rietsch, sometimes in the bile-ducts and gall-bladder, but it never occurs in the other organs or in the blood. It has been observed in small numbers on several occasions in the vomit of cholera, but Flugge suggests that in these cases the vomited matter may have been the intestinal contents which had pa ed into the stomach. The bacilli are usually minute, and curved like a comma, though at times (as almost always in drop cultivations) they form by the continuous adhesion of the individual bacilli long screw-like filaments. These fragments, or individual bacilli, which vary in length from 0'8 to 2 ft (averaging about T5 ft) and have a thickne of from J to i their length, are in their youngest state slightly curved or straight, and when more fully developed distinctly curved, sometimes showing a full half-circle. They are usually very active, shooting forward or turning round their axis. The longer spirilla have a slower and more oscillating motion. Under various conditions, as on moist linen or moist earth, they multiply very rapidly. Spore-formation has never been observed with certainty. The s. liquefies gelatin slowly, both in punctures and on plates. In punctures it forms a thin tube, funnel-shaped toward the surface of the gelatin, where it has a diameter after 48 hours of about i ctm. The funnel contains liquid the level of which is often lower than the surface of the gelatin. It is not till after from 4 to 6 days that the liquefaction has extended to the margin of the gla at the surface of the gelatin. On the plates it forms after 24 hours at 22 C. very minute white points which appear under a low power of the microscope as small, round, whitish-yellow discs which are so refracting that the surface of the plates seem as if sprinkled with bits of gla . These discs, which have an irregular, wavy, not sharply defined margin, become gradually larger, and retain their color, except that the central point becomes somewhat darker. They form, on liquefying the gelatin, funnels containing fluid, the colonies lying at the bottom of the funnels. After 48 hours1 growth at 22 C. these funnels measure hardly 1 mm. in diameter at the surface. On the surface of agar-agar the bacillus forms a grayish-yellow, gelatinous, folded coating without liquefying the substratum. Unlike the S. Finkler-Prior, it does not grow at all on potatoes at ordinary temperatures, and at higher temperatures forms only a slight, brownish mucous coating. The organisms develop in large numbers in blood-serum, neutralized meat infusion, and milk, the milk not being sensibly altered in character. According to Flugge, in none of the cultivations is there any development of putrefactive gases or foul odor. Buchner a erts, however, that a foul smell was observable in his cultivations of the bacilli in meat infusions. As the bacilli are sensitive to acids, the nutrient jelly, meat infusions, etc.. must be slightly alkaline or accurately neutralized. Though the bacilli develop best when in contact with the oxygen of the air, they grow even where that gas is absent, if other conditions are favorable. No growth occurs below a temperature of '16 C., and at 1? C. only a slight growth (Koch). The gelatin cultivations are usually made between 22 C. and 25 C.; between 30 C. and 40 C. the gelatin is completely liquefied. The bacilli are more sensitive to drying than almost any other bacteria, dying in from 2 to 3 hours at the ordinary temperature if spread out in the air on a cover gla . Hence infection through the air is impo ible, unle perhaps in the exceptional cases where bubbles, detached by agitation from infective fluids, might be carried for short distances by currents of air. The presence of saprophytic bacteria, especially when in exce or when the conditions as regards nutrition, temperature, etc., are unfavorable to the comma bacilli, leads rapidly to the death of the latter. According to Koch, if added to sewage, they can not be found after 24 hours, and in impure water they are said to die in 6 or 7 days except when in vfry large numbers. They will live even at 10 C.: boiling the fluid containing them, or exposing them for half an hour to a temperature of 60 C., causes their destruction. Alcohol, iron sulphate, hydrochloric acid, and quinine check their development; mercury bichloride and carbolic acid are most effectual in killing them. Natural infection of animals is unknown, and experiments made on them by the usual methods have shown no certain pathogenic action. Rietsch, Koch, and other experiA, ape; A", at; A3, ah; A4, all; Ch, chin; Cli', loch (Scottish); [s. 520]