| Shiga-Kruse | Flexner | Strong | “Y” | |
| Mannite | Blue | Red | Red | Red |
| Maltose | Blue | Red | Blue | Blue |
| Saccharose | Blue | Blue | Red | Blue |
The following table gives the more important cultural characteristics of the intestinal bacilli which might be confused with the various strains of dysentery bacilli.
Key for column headings:
A - Motility
B - Milk coagulation
C - Glucose
D - Maltose
E - Lactose
F - Mannite
G - Saccharose
H - Glucose neutral red bouillon
I - Butt
J - Slant
K - Indol
| Litmus Milk | Russel’s Medium | ||||||||||||
| A | B | 1st day | 3d day | C | D | E | F | G | H | I | J | K | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| B. faecalis alkaligines | + | - | Alk | Alk | O | O | O | O | O | O | O | O | - |
| B. typhosus | + | - | A | A | A | A | O | A | O | O | A | Alk | - |
| B. dysenteriae (Shiga-Kruse) | - | - | A | Alk | A | O | O | O | O | O | A | Alk | - |
| B. dysenteriae (Flexner-Strong) | - | - | A | Alk | A | A | O | A | O | O | A | Alk | - |
| B. dysenteriae “Y” | - | - | A | Alk | A | O | O | A | O | O | A | Alk | + |
| B. Morgan No. 1 | + | - | O | O | A G | O | O | O | O | G | .. | .. | + |
| B. paratyphosus A | + | - | A | A | A G | A G | O | A G | O | G | A G | Alk | - |
| B. paratyphosus B | + | - | A | Alk | A G | A G | O | A G | O | G Fl | A G | Alk | - |
| B. enteriditis (Gaertner.) | + | - | A | Alk | A G | A G | O | A G | O | G Fl | A G | Alk | - |
| B. coli | + | + | A | A | A G | A G | A G | A G | O | G Fl | A G | A | + |
| B. lactis aerogenes | - | + | A | A | A G | A G | A G | A G | A G | G Fl | A G | A | - |
| B. cloacae | + | + | O | A | A G | A G | A G | A G | A G | G Fl | A G | Alk | + |
| B. proteus vulgaris | + | .. | O | Alk | A G | A G | O | O | A G | G | A G | Alk | - |
Of the above tabulated nonspore bearing, Gram-negative, intestinal bacilli only B. lactis aerogenes shows capsules and only B. cloacae and B. proteus vulgaris liquefy gelatin. In the table + = positive, - = negative, O = no change, A = acid, Alk = alkaline, G = Gas and Fl = fluorescence in neutral red bouillon.
Epidemiology.—There is probably no disease, with the possible exception of cholera, where those attending a patient are so liable to have their hands contaminated with infectious material.
The terrible frequency of the stools and the tendency of the mucilaginous mucoid mass to become smeared over the buttocks and clothing of the patient make it onerous for an attendant to carry out methods of personal protection. In a family, where the mother may have to care for a sick child, and prepare food for the other children and herself, the opportunities for the spread of the infection in the family are great. In military barracks, as well as in other institutions where large numbers make use of the same water-closet accommodations, the chances of contamination of the seat by a patient responding to the frequent and imperious demands for evacuation are most probable, with subsequent transference of the infectious material to others. Bacillary dysentery is peculiarly an institutional disease and tends to spread in jails, orphan asylums and the like. A carrier is a particular source of danger in such an institution.
Not only is there the danger from a patient ill with bacillary dysentery but as well that from the convalescent or chronic carrier. Such carriers are particular sources of danger where they take part in the preparation of food for others. It is now thought that the striking prevalence of the disease in insane asylums is associated with the difficulty of making such patients observe the proper care of their hands as well as their persons.