London's Pulse: Medical Officer of Health reports 1848-1972
View report page
Hints from the Health Department. Leaflet from the archive of the Society of Medical Officers of Health. Credit: Wellcome Collection, London
London County Council 1899
[Report of the Medical Officer of Health for London County Council]
This page requires JavaScript
Continued from previous page...
| Expt. | Description of the samples. 1. | Total number of bacteria in 1 c.c. 2. | Number of spores of bacteria in 1 c.c. 3. | Number of bacteria causing liquefaction of the gelatin in 1 c.c. 4. | Remarks. 5. |
|---|---|---|---|---|---|
| 6 | Thames water, sample taken in mid-stream at Twickenham, opposite Ham house, i.e., about half-way between Glover's island and Eel Pie island. 11 a.m., Nov. 22,1898 (very wet weather). | 3,000 | 18 | No record. | Spores of B. enteritidis sporogenes present in 10 c.c., 5 c.c., 1 c.c., 0.1 c.c. of the water; absent in 0.01 c.c. In a phenol gelatine plate culture containing 0.01 c.c. of the water, one colony indistinguishable from B. coli. Subcultures from this colony gave the following results: Gas in 24 hours in gelatine shake culture incubated at 20° C. Diffuse cloudiness in broth in 24 hours at 37° C. No indol in five days. Slight acidity but no clotting in litmus milk in 48 hours at 37° C. In 96 hours, however, the milk showed a solid clot. In an ordinary gelatine plate culture containing 0.01 c.c. of the water, one colony indistinguishable from B. coli. Subcultures from this colony gave the following results: Gas in 24 hours at 20° C. in gelatine shake culture, diffuse cloudiness in broth in 24 hours at 37° C.; acidity but no clotting in litmus milk culture in 24 hours at 37° C. No indol in broth culture, fourth day, at 37° C. |
V—DESCRIPTION OF SOME OF THE BACTERIA FOUND IN THE CRUDE
SEWAGE AND IN THE EFFLUENTS FROM THE COKE-BEDS.
1. B. Coli Communis.
2. B. Mesentericus.
Sewage Variety E.
Sewage Variety I.
3. Sewage Proteus.
4. B. Frondosus.
5. B. Fusiformis.
6. B. Subtilissimus.
7. B. Subtilis.
Sewage Variety A.
Sewage Variety B.
8. B. Membraneus Patulus.
9. B. Capillareus.
1. Bacillus Coli Communis.
[An aerobic, non-chromogenic, slightly motile, non-liquefying bacillus.]
Source.—The excreta of human beings and many of the lower animals. Very abundant in London crude
sewage; usually more than 100,000 per c.c. of sewage.
Morphology†.—Small bacilli with rounded ends, hardly longer than broad; solitary, often in pairs; rarely
in chains containing more than two segments.
Motility.—Usually only feebly motile.
Spore formation.—No spores are formed.
Flagella.—Dr. M. H. Gordon gives the flagella average as 1 to 3.
Temperature.—Grows best at 37° C., but also very well at the ordinary temperature.
Gelatine plate cultures.—The colonies develop in from 24 to 48 hours at 20° C. The deep colonies are not
characteristic, the surface colonies peculiarly so, appearing as delicate, slightly granular films, of an irregularly
circular shape, which are bluish-white by reflected and of an amber colour by transmitted light; they are
transparent, and sometimes iridescent, especially towards the periphery, but at the centre and over the entire
surface in old cultures an opacity due to a greater thickness of the bacterial growth is observed; later these
surface colonies may become marked by concentric, or radiating, or irregular markings. The surrounding
gelatine frequently acquires a dull, cloudy, faded appearance. The gelatine is not liquefied.
Gelatine "stab" cultures.—The growth on the surface is like a surface colony in a plate culture, but tends
to be more luxuriant, due to the greater thickness of the medium. A white growth extends to the foot of the
stab, and gas fissures frequently appear in the gelatine. The gelatine, as already stated, is not liquefied.
Gelatine "streak" cultures.—The growth is like an elongated surface colony in a gelatine plate culture,
but is, perhaps, more luxuriant. Briefly, a delicate faintly-granular film forms, with transparent and irregular
margins. Down the centre, longitudinally, the growth is more opaque. Sometimes the film shows iridescence,
and in old cultures it may become irregularly thickened. The gelatine, which is net liquefied, becomes often
clouded. The growth, which is bluish-white by reflected light, has a yellowish-amber colour by transmitted
light.
Potato-gelatine plate, "stab" and "streak" cultures.—The growth is somewhat similar in appearance to the
above, but tends to be more circumscribed, is slower, and of a characteristic brown colour.
Phenol (0.05 per cent.) gelatine cultures.—These do not differ from ordinary gelatine cultures except that
growth is delayed.
Gelatine " shake " cultures.*—Numerous gas bubbles are formed, usually in 24 hours, at 20° C.
Agar plate cultures.—The growth is not so characteristic as in gelatine. The superficial colonies have a
moist glistening white appearance.
†¶* See figs. 6, 4, 13 and 5, Plate I. of First Report.
[5]