Toxic Products in Infected Pork

Abstract

Recent investigations have disproved the theory that living pathogenic organisms must be present in food in order to cause that train of symptoms usually associated with food poisoning. The work of Ecker and his associates, 1 Branham 2 and Geiger 3 clearly indicates that organisms of the paratyphoid group are capable of producing a heat resistant toxin in culture media. Dack, Jordan and Wood 4 have demonstrated that the killed bodies of paratyphoid bacilli are not toxic when ingested. The report of Pryer 5 shows that meat from which no organism of known pathogenicity could be isolated was toxic for human beings. Organisms other than those of the paratyphoid group such as B. proteus have been suspected of causing food poisoning.

We have also found B. proteus predominating in some raw sausages which after apparent sufficient cooking caused intestinal disturbance. It seemed of interest to us to investigate the nature of a toxin, if any, produced on meat and fish by B. proteus, B. paratyphosus B. and Staphylococcus albus. At first fresh meat was inoculated with our test organisms but was found to be so grossly contaminated that no conclusions were possible, Our results in these experiments were obtained from meat which was inoculated after autoclaving at 15 pounds for 15 minutes.

After inoculation the meat was kept at room temperature for periods of from 3 to 19 days, after which it was ground in a mortar and extracted with either alcohol or water. Water extracts were heated to 70° for 30 minutes. Alcoholic or ether extracts were evaporated to dryness in vacuo and resuspended in salt solution. Toxicity was determined by the intraperitoneal injection into young rats or white mice.