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No raft clotting was observed in 10 cc. (1 cockle) nor in any dilution up to .00001 cc.
(1/millionth part of cockle).
4. Number of colonics present on plated agar incubated at 37° C. for two days=
approximately 75,000 per cockle.
5. Number of colonies present on plated gelatine incubated at 20° C. for two days=
approximately 6,400 (of which 10 per cent. liquefied the media) per cockle.
The above results must be read in the light of the fact that the cockles were unshelled,
therefore, any liquor present in the shell was not examined. Also the presence of ealt would
inhibit in some degree the growth of organisms.
The presence of B. Coli in half a cockle and in no lesser part and the absence of
B. Welchii in one cockle or part of a cockle points to a good standard of cleanliness.
(Sd.) E. GOODWIN RAWLINSON, M.D., D.P.H.
Winkles.
A sample of winkles was purchased from a fish shop in the Borough. Ten of
the winkles were examined for bacteriological cleanliness and found to be
satisfactory. The following is the report of the examination: —
Ten winkles were cut up with sterile scissors and made up to 100 cc. with sterile water.
Both the body and liquor were used.
10 cc. of the fluid = l winkle, and dilutions were made up to 1/millionth part of a winkle.
1. MacCotikeys' Bile Salt Lactose Broth for presumptive test for B. Coli. Readings were
taken after two days' incubation at 37° C.
10 cc. = l winkle gave acid and gas (Positive).
5 cc. = ½ „ „ „ „ „ (Positive).
1 cc.=l/10 „ „ no reaction (Negative).
2. Glucose Formate Broth for Streptococci.—Microscopical examination after two days'
incubation at 37° C. showed streptococci to be present in 1/1,000 part of a winkle.
3. Litmus Milk for Presumptive B. Welchii.—The fluid and dilutions of the fluid were
heated to 80° C. for ten minutes, inoculated into Litmus Milk and cultured anserobically for
three days at 37° C.
No raft clotting was observed in any instance.
4. Number of colonies present on plated agar incubated at 37° C. for two days = l,780
per winkle.
5. Complete liquefaction occurred on plated gelatine incubated at 20° C. for two days.
Remarks.
The presence of Coliform organisms in only half a winkle and the absence of B. Welehii
in one winkle points to a good standard of cleanliness.
E. GOODWIN RAWLINSON, M.D., D.P.H,