Hints from the Health Department. Leaflet from the archive of the Society of Medical Officers of Health. Credit: Wellcome Collection, London
Report for the year 1925 of the Medical Officer of Health
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disposal arrangements were entirely altered some years ago after representations
by the Company to the Dutch Authorities and no sewage is now discharged where
it can gain access to the mussel beds. A suggestion was made with which the
bacteriologist acting for the Fishmongers' Company agreed, that sufficient care
had not been exercised by the fishermen as to the cleanliness of the bags in which
the mussels were packed; this was to be remedied.
Further examinations by the Fishmongers' Company of consignments going
to the London market gave satisfactory results and there appeared to be no further
cause for anxiety.
The following is the report of the bacteriological examination of the samples submitted from this Borough:— Technique. Short Method. Eyre.
No. of Mussels. | MacConkey's Bile Salt Broth for presumptive B. Coli. | Litmus Milk for presumptive B. Welchii. | Glucose Formation Broth for Streptococci. |
---|---|---|---|
From .2 c.c. of liquor | From 1 c.c. of liquor | From .2 c.c. of liquor | |
1 | Acid | Raft clotting | Streptococci present |
2 | Acid and Gas | — | — |
3 | Acid and Gas | — | — |
4 | Acid and Gas | — | Streptococci present |
5 | Acid and Gas | — | — |
6 | Acid and Gas | — | — |
7 | Acid and Gas | — | — |
8 | Acid and Gas | Raft clotting | Streptococci present |
9 | Acid and Gas | Raft clotting | -- |
10 | Acid and Gas | — | — |
RESULTS: 9 mussels containing B. Coli. 90 per cent. are therefore unclean.
3 out of 3 mussels contain B. Welchii.
3 „ 3 „ „ Streptococci.
Determination of B. Coli Index.
Identification of Coliform Organism.
5.6c.c. of the mussel liquor having already been used the following results obtained
should necessarily be slightly greater.
The liquor and mussels divided up were then made up to 100c.c. with sterile water;
therefore one mussel equals 10c.c. of fluid.
.05c.c. to plated agar incubated at 37°C. for 24 hours=66 colonies=132,000 colonies per
mussel.
.05c.c. to plated Gelatine incubated at 20°C. for 48 hours=2,000 colonies=400,000
colonies per mussel. Of these a large percentage were liquefiers, i.e., organisms causing
decomposition of proteins.