72
Negative cultures :--
1. Plate cultures showing no suspicious colonies, in 74 cases;
2. Suspicious colonies which failed to grow characteristically, in 19 cases; 3. Suspicious colonies which were proven negative by agglutination, in 3 cases; 4. Suspicious colonies which were negative by growing at room temperature, in
2 cases making a total of negative cultures of 98.
Positive cultures:
1. Plates showing typical colonies, consisting of Gram-negative diplococci of characteristic morphology, but which failed to grow on subculture. There were usually two or three colonies transplanted. On the basis of previous experience, it was thought proper to include these with the positive cultures. They are as follows :--
Serial No.
Time in Gaol (years).
1 12
Degree of Infection.*
Prison No,
Age (years).
7
5393
20
plus-minus
46
5084
25
2012 and 9 days
1 plus
70
5163
30
97
5-167
27
2/12 1.12 and 5 days
plus-minos
plus-minus
182
971
28
5. 12 and 14 days.
plus-minus
2. Plates showing typical colonics, consisting of Gram-negative diplococci of characteristic morphology; producing acid in dextrose and maltose, but not in saccharose medium; showing no growth at room temperature, but a typical growth on subculture (ready emulsification, no pigment, etc.); showing no agglutination in saline or normal horse serum (1:50) controls, but giving no agglutination with type or polyvalent antimeningococcic
serum:
Serial No.
Prison No.
Age (years).
زاد
5094
31
Time in gaol
(years). 2:12 and 7 days
Degree of
infection.
2 plus
75
5633
27
14 days
1 plus
76
5666
30
11 days
2 plus
100
5101
22
2/12 and 7 days
I plus
124
775
34
32
1 plus
:
3. Plates showing colonies having the characters mentioned above (under “2”) but possessing definite agglutination reactions with polyvalent or type serum or both :---
Serial Prison Age
No. No. (years).
Time in gaol (years).
Degree of infection
No. of Agglutination reactions
colonies
tested.
(dilutions of 1:50 and 1:100). †
Type.
poly., 2 plus.
poly., 2 plus.
1 900
53
112.
plus-minus.
1
normal, 2 plus.
normal.
para, negative.
20 5438
21
1/12 and 6 days. plus-minus.
poly., 2 plus.
21 | 5182
1/12 and 29 days.
2 plus.
1
normal, 1:50, 1 plus. para, 2 plus.
normal, 2 plus.
para, negative.
irregular. para.
卡
normal.
* In the above series the term "degree of infection" is used to mean the relative number of colonies of meningococcus noted on the plate cultures. This gives an indication as to the extent of infection of the nasopharynx. Hence 4 plus signifies a pure culture; 3 plus, that the meningococcus is the predominating organism; plus, numerous colonies of meningococci but other organisms predominating; 1 plus, the presence of only a few colonies; and plus-minus, that the meningococcus is present to the extent of only an eccasional colony.
"2 plus" in ficates complete agglutination in a dilution of 1:100; 1 plus indicates incomplete agglutination in the dilution stated.