(7) Wash in water.
(8) Apply Löffler's methylene-blue solution one-half minute.
(9) Rinse in water, dry between filter-papers, and examine with the one-twelfth objective.
When the bacilli are scarce, the following method may be tried. It is applicable also to other fluids. If the fluid is not albuminous, add a little egg-albumen. Coagulate the albumen by gentle heat and centrifugalize. The bacilli will be carried down with the albumen. Separate the albumen, mix with artificial gastric juice (for preparation of which see test for pepsin, [p. 222]), and set in an incubator or warm place until digested. Finally, centrifugalize and stain as described above. The bacilli do not stain so well as in the ordinary methods.
A careful search of many smears may be necessary to find the bacilli. They usually lie in clusters (see Plate V). Failure to find them in suspicious cases should be followed by inoculation of guinea-pigs; this is the court of last appeal, and must also be sometimes resorted to in order to exclude the smegma bacillus.
In gonorrhoea gonococci are sometimes found in the sediment, but more commonly in the "gonorrheal threads," or "floaters." In themselves, these threads are by no means diagnostic of gonorrhea. Detection of the gonococcus is described later ([p. 264]).
| PLATE V |
| Tubercle bacilli in urinary sediment; X800 (Ogden). |
7. Animal parasites are rare in the urine. Hooklets and scolices of Tænia echinococcus (Fig. 55) and embryos of Filaria sanguinis hominis have been met. In Africa the ova, and even adults, of Distoma hæmatobium are common, accompanying "Egyptian hematuria."
| FIG. 55.—1, Scolex of tænia echinococcus, showing crown of hooklets; 2, scolex and detached hooklets (obj. one-sixth) (Boston). |