The use of Preserved Bacterial Suspensions for the Agglutination Test: With especial reference to the Enteric Fevers and Typhus Fevers

Abstract

1. In B. typhosus, B. paratyphosus A and B, and B. enteritidis Gärtner, low concentrations of phenol and formaldehyde produce a definite inhibition of the 0 agglutination, while the H agglutination is unaltered—a fact already established many years ago in the case of B. proteus X 19.2. Alcohol, even in high concentrations, has no such inhibitory effect.3. Therefore, suspensions preserved in the usual way with phenol or formalin are not adequate reagents for the qualitative serum analysis in enteric fevers or for the usual diagnosis test in typhus fever.4. Phenol and formalin suspensions are responsible for negative results of the Widal test in cases of enteric fevers which show only the 0 immune body in the serum; such cases form a considerable percentage of the total especially in typhoid fever.5. As a routine measure in the diagnosis of enteric fevers, it is suggested that two preserved suspensions of each organism be used:(1) an alcoholic suspension (like that of Bien and Sonntag in typhus fever) as a reagent for the 0 agglutinin, and(2) the usual phenol or formalin suspension as a reagent for the H agglutinin.6. The nature of the described phenomenon of inhibition is not, as yet, entirely clear.