Tetanus carriers in experimental animals.

Abstract

The demonstration that human carriers of tetanus bacilli have antitoxin in their blood has opened up a number of problems, which we are attempting to solve on experimental animals. We had first to determine whether carriers could be produced in these animals and if so whether antitoxin would be formed. The results of this preliminary experiment we will report on here and subsequently we hope to give the results of our further studies.

That we would succeed in establishing tetanus bacilli in the digestive tract of guinea pigs was indicated by our finding that 27 per cent of our stock animals were already carriers and that these animals had antitoxin in their serum. On the other hand, we have failed to find a rabbit that carried these organisms nor have we detected tetanus antitoxin in the serum of a number of rabbits examined.

As we planned to use the animals for other experiments a large number of guinea pigs were selected whose stools were free from tetanus spores and whose serum showed no antitoxin. These animals were starved for a day and were then fed a large number of washed spores and bacilli from month old bouillon cultures which were added to their usual food. After the feeding the animals were placed in metal cages which were sterilized from time to time. In order to prevent, as far as possible, infection from the outside all bedding and, with the exception of green stuffs which were washed, all food was autoclaved before it was placed in the cages.

The results of the stool examinations made on these guinea pigs, approximately four months after the feeding of tetanus cultures, are summarized in Table I.