The conditions which favour the vitality, growth and multiplication of the typhoid bacillus are the following: the soil should be pervious; it should be permeated with a sufficiency of decaying - preferably animal - organic matters; it should possess a certain amount of moisture, and be subject to a certain temperature.
Of the lower animals, mice, rats, guinea-pigs, rabbits, squirrels and monkeys are susceptible to the bacillus; horses, cattle, sheep, goats, pigs, dogs and cats are more or less resistant, but cats and dogs have been known to die of plague (Oporto, Daman, Cutch and Poona).
About 1880 Pasteur first showed that Bacillus anthracis cultivated in chicken broth, with plenty of oxygen and at a temperature of 42-43° C., lost its virulence after a few " generations," and ceased to kill even the mouse; Toussaint and Chauveau confirmed, and others have extended the observations.
- A plate-culture colony of a in more complex multispecies of Bacillus - Proteus (Hauser) cellular organisms. To - on the fifth day.
Only a single pathogenic species can withstand the short boiling to which milk is ordinarily treated in domestic management, and this is the anthrax bacillus containing spores.
Given the bacillus, the questions arise, How is it disseminated?
By growing this bacillus in broth a toxin is formed which remains in solution and can be separated from the bacilli themselves by filtration.
By 1876 the anthrax bacillus had been obtained in pure culture by Koch, and some other pathogenic bacteria had been observed in the tissues, but it was in the decade 1880-1890 that the most important discoveries were made in this field.
Of the dry antiseptics iodoform is constantly used in septic or tuberculous wounds, and it appears to have an inhibitory action on Bacillus tuberculosis.
Glucose also undergoes fermentation into lactic acid in the presence of the lactic acid bacillus, and into butyric acid if the action of the preceding ferment be continued, or by other bacilli.
By the discovery of the bacillus of tubercle, the physician has been enabled to piece together a long and varied list of maladies under several names, such as scrofula and lupus, many of them long suspected to be tuberculous, but now known to belong to the series.
It may be diminished or its increase prevented by a diet from which red meat and meat extracts are excluded, by the use of the lactic acid bacillus, by the administration of laxatives and cholagogues to regulate the bowels, and by the use of iodides and nitrites.
This disease is due to the presence of large numbers of Bacillus solanacearum in the tubes through which water is conveyed to the leaves from the roots.
All these terms, including the usual one of bacteria, are unsatisfactory; for " bacterium," " bacillus " and " micrococcus " have narrow technical meanings, and the other terms are too vague to be scientific. The most satisfactory designation is that proposed by Nageli in 1857, namely " schizomycetes," and it is by this term that they are usually known among botanists; the less exact term, however, is also used and is retained in this article since the science is commonly known as " bacteriology."
Resemblances also exist between the endospores and the spore-formations in the Saccharomycetes, and if Bacillus inflatus, B.
Bacillus, little rod or stick.
He proceeded in the main on the assumption that the forms of bacteria as met with and described by him are practically constant, at any rate within limits which are not wide: observing that a minute spherical micrococcus or a rod-like bacillus regularly produced similar micrococci and bacilli respectively, he based his classification on what may be considered the constancy of forms which he called species and genera.
- Bacillus subtilis.
- Stages in the development of spores of Bacillus ramosus (Fraenkel), in the order and at the times given, in a hanging drop culture, under a very high power.
P. r; Sturgis, " A Soil Bacillus of the type of de Bary's B.
They were confirmed, but met with little acceptance in the scientific world, which was preoccupied with the claims of a subsequently discredited Bacillus malariae.
In 1880, two years before Koch discovered the bacillus of tubercle, C. L.
In the laboratory absolute soil dryness is as distinctly antagonistic to the vitality of the diphtheria bacillus as soil dampness is favourable.
Robertson has shown that the typhoid bacillus can grow very easily in certain soils, can persist in soils through the winter months, and when the soil is artificially fed, as may be done by a leaky drain or by access of filthy water from the surface, the microorganism will take on a fresh growth in the warm season.
The lactic acid bacillus, always present in unboiled milk (to which the souring of milk is due), is easily destroyed by heat; but the bacillus mesentericus, often found in it, forms spores, which are not destroyed by ordinary boiling, and germinate when the milk is kept at a moderately warm temperature, producing a brisk fermentation whereby a large volume of gas is liberated.
Fitz (Ber., 1878, 11, p. 52) found that the butyric fermentation of starch is aided by the direct addition of Bacillus subtilis.
The melancholy incident illustrates several points of interest: (1) the correctness of the bacterial theory of causation, and the identity of the bacillus pestis as the cause; (2) the infectious character of the pneumonic type of disease; (3) its high fatality; (4) the difficulty of diagnosis.
The report also considers it proved that the bacillus pestis multiplies in the stomach of a flea and may remain a considerable time within its host.
Klein also prepares a new prophylactic from the dried organs of a guinea-pig, and one of the most interesting experiments is that of Strong (Archiv far Schiff sand tropische Hygiene, April, 1906), who uses for producing immunity in man a living virulent culture of the bacillus pestis.
This disease depends upon the presence of a bacillus which grows rapidly at the back of the throat and in the airpassages specially of children, causing the formation of a membrane which, by plugging the windpipe, causes suffocation and death.
Bacillus subtilis, Cohn, and Spirillum undula, Ehrenb.
- The various phases of germination of spores of Bacillus ramosus (Fraenkel), as actually observed in hanging drops under very high powers.
Only three or four times as long as broad (Bacterium), or longer (Bacillus); the biscuitshaped ones are Bacteria in the early stages of division.
- Bacillus e nthracis.
- Curve of growth of a filament of Bacillus ramosus (Fraenkel), constructed from data such as in fig.
Those of Bacillus subtilis measure o.
A, Bacillus anthracis.
(2) By far the majority of the described species (over woo) fall into the three genera - Micro- coccus (about 400), Bacillus (about 200) and Bactridium (about 150), so that only a quarter or so of the forms are selected out by the other genera.
- Stages in the formation of a colony of a variety of Bacillus (Proteus) vulgaris (Hauser), observed in a hanging drop. At I I A.M.
A definite bacillus to which the peculiarly fine flavour of certain butters is due, is said to be largely employed in pure cultures in American dairies, and in Denmark certain butters are said to keep fresh much longer owing to the use of pure cultures and the treatment employed to suppress the forms which cause rancidity.
In the last decade of the 19th century the chief discoveries were of the bacillus of influenza (1892), of the bacillus of plague (1894) and of the bacillus of dysentery (1898).
Before the discovery of the bacillus of tubercle, scrofula and tuberculosis were regarded as two distinct diseases, and it was supposed that the scrofulous constitution could be distinguished from the tubercular.
Quite irrespective of the nature of the anatomical lesion, the finding of the diphtheria bacillus on the part affected and the inoculability of this upon a suitable fresh soil are the sole means by which the diagnosis can be made certain.
The path by which the bacillus enters the body varies.
The bacillus is non-resistant and easily killed by heat and germicide substances, particularly acids.
The bacillus has been demonstrated in the bodies of fleas, flies, bugs and ants.
The supposed constancy of forms in Cohn's species and genera received a shock when Lankester in 1873 pointed out that his Bacterium rubescens (since named Beggiatoa roseo-persicina, Zopf) passes through conditions which would have been described by most observers influenced by the current doctrine as so many separate " species " or even " genera," - that in fact forms known as Bacterium, Hicrococcus, Bacillus, Leptothrix, &c., occur as phases in one life-history.
Bacillus typhi, Gaffky.
In other words, animals vaccinated with the cultivated bacillus showed immunity from disease when reinoculated with the deadly wild form.
The questions as to the causes and nature of the changes in the bacillus and in the host, as to the extent of immunity enjoyed by the latter, &c., are of the greatest interest and importance.
Sporogenous rodlets cylindric, not altered in shape: - Bacillus (Cohn), non-motile; Bactrinium (Fischer), motile, with one polar flagellum (monotrichous); Bactrillum (Fischer), motile, with a terminal tuft of cilia (lophotrichous); Bactridium (Fischer), motile, with cilia all over the surface (peritrichous) .
- A plate-culture of a bacillus which had been exposed for a period of four hours behind a zinc stencil-plate, in which the letters C and B were cut.
Bacillus chauvaei ferments cane-sugar solutions in such a way that normal butyric acid, inactive lactic acid, carbon dioxide, and FIG.
These are found to contain large numbers of a bacterium termed Bacillus radicicola or Pseudomonas radicicola.