Paraagglutination

Paraagglutination, the formation of agglutinins in relation to a microbe that is not the cause of a given disease but exists in symbiosis with the causative microbe. The phenomenon of P. was first described by Kuhn and Woithe in dysentery. They investigated 19 cases of dysentery, and in one patient's stool, three microbes were isolated: the Flexner dysentery bacillus, the colon bacillus, and a Gram-positive coccus (resp. coccobacillus), and all these bacteria were agglutinated by specific dysentery serum: the colon bacillus up to a dilution of 1:20,000, i.e., higher than the dysentery bacillus, and the coccobacillus up to a dilution of 1:3,000. Kuhn and Woithe immunized rabbits with the isolated strains, and the serum obtained with the Flexner strain agglutinated the Flexner dysentery bacillus up to a dilution of 1:6,000, and the colon bacillus and coccus up to a dilution of 1:3,000; the serum obtained with the colon bacillus agglutinated its own strain up to 1:20,000, and the Flexner bacillus up to 1:1,000 and the coccus up to 1:3,000; the serum obtained from immunization with the coccus agglutinated its own strain and the colon bacillus up to 1:6,000 and the dysentery bacillus up to 1:600. The phenomenon of P. was subsequently studied by a number of researchers (Kummebeling, Breinl, Gaentgens, Busson, Giesczykiewicz, Zil'ber and others.). P. must be differentiated from both group and accompanying agglutination (heterological). The distinction from the first presents no particular difficulties (in group agglutination, the matter concerns the agglutination of microbes that are related in a biological sense, in P. the parastrain is sometimes agglutinated in higher dilutions than the main strain). It is more difficult to distinguish P. from accompanying agglutination (Nebenagglutination). Thus, the agglutination of Proteus X₁₉ by some researchers is considered P. (Otto, Zil'ber), while others tend to see it as accompanying agglutination, based on the fact that the X₁₉ culture firmly retains its agglutinability in relation to typhus serum; in contrast, the serological properties of paraagglutinating strains do not possess particular stability and change over time. Zil'ber gives a specific scheme to guide in judging whether a particular strain belongs to paraagglutinating ones. This scheme is as follows: 1. Paraagglutinating strains become so as a result of coexistence with other microbes, and in most cases, the microbes with which parastrains coexist are causative agents of various infections. 2. Paraagglutinating strains of the same species of microbe are not homogeneous in serological and antigenic relations. 3. The ability to paraagglutinate is preserved in different parastrains for varying periods—from several days to several years, but in most cases not for long. 4. The ability of a microbe to become a paraagglutinating strain is individual, since from the same material, along with paraagglutinating ones, ordinary microbes of the same species can be isolated. 5. The ability to paraagglutinate can be acquired by both bacteria belonging to the same group as the microbe in relation to which the phenomenon of P. occurs, and microbes that are biologically distant from it. In the first case, to determine whether it is a matter of group agglutination or P., it is necessary to consider the origin of the strain; if it was isolated from material in which it was mixed with the causative microbe, then it is possible to assume the presence of P. in this case. Some researchers are skeptical about the very existence of the phenomenon of P. Breinl, for example, proposes to completely abandon this term. The cause of P. some researchers see in the fact that in the patient's body, foreign microbes produce new, additional receptors identical to the receptors of the infectious agent, while according to others, the phenomenon of P. is connected with the fact that foreign bacteria adsorb the antigen of the disease-causing microbe. There is also an opinion according to which the metabolic products of the disease-causing microbe change the metabolism of the microbe coexisting with it and make it capable of producing the same products that caused its change.