[Report of the Medical Officer of Health for Port of London] page 30

Port of London 1929

[Report of the Medical Officer of Health for Port of London]

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Table: (3) SAMPLES OF FOOD EXAMINED DURING THE YEAR.

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(3) SAMPLES OF FOOD EXAMINED DURING THE YEAR.

Date. 1929.	Sample.	Analyst's Report.	Action taken.
Jan. 25	Potted Meat	"I have not finished examining the pot of partridge paste you sent yesterday, and I shall not be able to report finally till the beginning of next week, as I am feeding mice on it. Meanwhile you may like to know that I can find nothing amiss with it. There is a little gas in the crevices, and that is all. On opening, I find the meat perfectly sweet, normal to taste and smell, and sterile on aerobic culture on agar plates and in broth. Stained films show no micro-organisms. Two mice fed exclusively on the meat since yesterday are to-day normal, but I must give them till Monday, and the anaerobic cultures must wait till then before I examine them. "It will be interesting if you can find out why the stuff was returned."	Consignment released for examination purposes only.
„ 29		"I can now add to my first report the fact that the material is not absolutely sterile, but contains an anaerobic bacillus (probably as spores). All aerobic cultures—four in number— show no sign of any growth—but both the tubes of chopped meat medium (designed for anaerobic growth) showed yesterday growth of a spore-bearing anaerobe and had a somewhat offensive smell. It would involve a good deal of time and trouble to determine the species, though 1 could doubtless do it if you thought it worth while. But there is one species which it is vital to exclude, and that is B. botulinus. This, I think, I have done. The two mice fed exclusively on the paste for two days have remained in good health, though, in addition, each received on the fourth day a subcutaneous injection of the anaerobic chopped meat broth culture. Yesterday I gave a guinea-pig an injection of 1 c.cm. of this same culture. It is perfectly well to-day. The culture was four days old, and there had been ample time for the formation of toxin. The toxin is so potent, and the dose was so large, that, had it been present, serious results must have ensiled inside 24 hours. There is thus a strong presumption that the anaerobic is not B. botulinus, but I shall watch the animals for another day or two. "Mv reading of the matter is this: A few spores of some anaerobe capable of breaking down protein, escaped destruction in sterilizing the paste. Slight chemical changes have since occurred—hence the gas bubbles in the crevices in the paste, but no change (in the pot sent to me) sufficient to cause smell or unpleasant taste. "Of course, other samples, taken abroad, may have been much worse and led to the rejection of the consignment."
Feb. 11	Black Currant Pulp.	"I opened this tin on February 8th. It was, as you say, blown, but there was not much pressure of gas inside. The contents appeared to me good, and I could detect nothing abnormal in smell or taste. The material was intensely acid. It is difficult to determine the exact p H by colorimetric methods in such deeply-coloured material, but as far as I can determine it is between p H 3 and 4, at which acidity I conceive that few pathogenic organisms could grow. "I found no yeasts and no obvious bacteria in stained films, and cultures have remained sterile (three days), both aerobic and anaerobic. I do not think there could be any objection to the use of this pulp for making jam."	Consignment released.
Aug. 30	Cream	The tin was opened under aseptic conditions. The contents had separated into three elements: almost clear yellow fat, curd-like semi-solid material and a thin milky fluid. Reaction —faintly acid (P_H—6-2). Wet Films: Besides fat globules, the material contains masses of acicular crystals having a radial arrangement, the physical properties of which show that they are either neutral fats or fatty acids. Stained Films (Gram & Ziel Neelsen): No micro-organisms are distinguishable. Cultures were made as follows:— Shake cultures from decimal dilutions in 1. Agar at 37° C. 2. Gelatin at 20° C. In milk (aerobic and anaerobic) at 37° and 20°. In meat broth. In Brilliant Green broth. All these cultures were sterile. Animal Experiment: Three mice were fed on liberal amounts of the material for three days. They have developed no	Consignment-released for manufacturing purposes.