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44
As none of the suspected food was available for examination, the faeces of the
three patients were examined bacteriologically and the blood of Mr. and Mrs. L.
tested serologically by Sir Frederick Andrewes, the City Bacteriologist. A sample
of the proprietary blancmange powder referred to above was also examined.
The following is a copy of Sir Frederick Andrewes's report:—
"HISTORY.
"September 2nd, 1922.—Ox-cheek and beef-skirt bought and stewed together.
"September 3rd.—Ox-cheek eaten by family and given to dog.
"September 4th.—Beef-skirt eaten by family and given to dog.
"September 5th.—MRS. L. seized at mid-day with epigastric pain, followed by vomiting
"and diarrhoea. Temperature 100° F. on two following days. Severe diarrhoea persisted
"for a week or more.
"MR. L. on night of 5th, had pain and nausea, followed by diarrhoea for two days,
"but no vomiting or fever.
"MISS L. had epigastric pain and nausea but no vomiting or diarrhoea.
*THE DOG had diarrhœa.
"On September 7th, I received stools from the three cases. These were examined (a)
"by direct plating on lactose litmus agar, and (b) by inoculation into brilliant green broth of
"3 strengths in each case, the resulting growth being plated next day on lactose litmus agar.
"THE DIRECT PLATING was successful only in the case of Mr. L.—colonies of a
"Salmonella being obtained.
"THE BRILLIANT GREEN METHOD was" readily successful in all three cases"Salmonella
colonies being obtained from all.
"CULTURALLY the bacillus presented the classical character of the Paratyphoid
"B Group. It was mobile, actively reduced neutral red, formed no indol, fermented glucose.
"mannite and vulcite with formation of gas, failed to ferment lactose and saccharose, and
"formed alkali in litmus milk.
"SEROLOGICALLY the bacillus proved to be a B. Aertrycke (the so-called ' Mutton
"type which is the commonest cause of food-poisoning in this country). (In determining
"this fact I made use of methods now in course of publication, based on the fact that in all
"old Salmonella cultures there exist side by side bacilli of highly specific, and of almost
"unspecific character, but mutually convertible on subculture. I have sera of each type,
"in the case of all common food-poisoning bacilli and also a stock of already absorbed sera,
"reacting each with its own type alone).
"IN THE CASES OF MRS. L. AND MISS L., I found, amongst a majority of unspecific
"colonies, one colony yielding the specific agglutinations of B. Aertrycke, in each case, which
"is sufficient to identify the nature of the bacillus. In the case of Mr. L., all of the ten
"colonies tested proved unspecific. I therefore put the strain through daily broth culture
"to allow of mutation and this procedure was successful. The fourth broth sub-culture was
"plated on agar and ten colonies were picked and tested; 6 colonies proved specific Aer"tryckes
and 4 unspecific. The evidence is, therefore, complete in all three cases, that the
" infecting organism was B. Aertrycke.
"TESTS OF THE PATIENTS' SERUM.—Dr. White provided me on September 12,
"7 days from onset, with blood from Mr. and Mrs. L. but not from Miss L., who had gone
"away. The sera were put up against a long series of specific and unspecific emulsions
"of food poisoning and other bacilli, and yielded unspecific results corresponding to the
"unspecific nature of the bacillus from the stools. The titres for my standard Aertrycke
"emulsion were Mr. L., 1: 440 =92 units; Mrs. L., 1: 250 =52 units. But these were
"also agglutinated unspecific strains of Paratyphoid B, Paratyphoid C, and B. Newport,
"as well as unspecific Aertrycke, though not to quite so high a titre. They failed to agglutinate
"specific strains of any, not even of B. Aertrycke. If I had not known the infecting agent,
"I should have been in doubt to which of these salmonellas infection was due. I should
"add that Mr. L.'s serum (and not Mrs. L.'s) agglutinated B. Typhosus to 1: 150 and specific
"B. Paratyphosus B. to 1: 30, suggesting former T.A.B. inoculation, concerning which I
"am making enquiries.
"SOURCE OF INFECTION.—The ox-cheek, which Dr. White suspects as the cause,
"had all been used up, as had the beef-skirt.
" A sample of pink blancmange powder which had been used, was sent to me on September
"8th. Cultures in brilliant green broth were negative, and two mice fed on it exclusively for
"three days were unharmed.
"(Signed) F. W. ANDREWES."
"St. Bartholomew's Hospital,
"September 16th, 1922."
It is difficult to incriminate any special article of food, principally on account
of the fact that Miss H. escaped attack, although she partook of the meal which
would appear to be the only food consumed in common by the whole household