Studies on Meningococcus Infection

Abstract

In the two preceding papers, it has been shown that freshly isolated strains of meningococcus differ not inconsiderably from those strains maintained in the laboratory on artificial media over long periods, and known as stock strains. Amongst the observations which have been recorded is the ability of fresh strains to evoke the production of precipitin-containing sera (1) which will react specifically with the type-specific substances occurring in these same fresh strains (2). This and other related observations pointing to the probability that the meningococcus has an antigenic complex comparable, in its essentials, to that described for other organisms--especially those of the nonencapsulated group (3)--are described in some detail in this and the following paper which deal with the isolation and analysis of some of the antigenic components.That precipitation reactions between soluble extracts of the meningococcus and antimeningococcal sera occur and are of some importance diagnostically is no new observation. As long ago as 1906, Bruclmer and Cristeanu (4) showed that, while extracts in 0.75 per cent NaC1 are but feeble precipitinogens, extracts of meningococci prepared in 0.15 per cent NaOH give good precipitates on the addition of antimeningococcal serum, but not with normal horse serum. They showed, moreover, that the meningococcal extract precipitates with antigonococcal serum and that the same cross-precipitation occurs when an alkaline extract of gonococci is set up with antimeningococcal and antigonococcal sera. Dopter and Koch (5) confirmed these results and introduced the conception of co-precipitins to account for the cross-reactions. They showed that when the antimeningococcal serum is absorbed with whole meningococci both the specific meningococcus precipitins and also the group precipitins, which react with the gonococcus extract, are removed; on the other hand, when the serum is absorbed with whole gonococci, 341on May 12, 2018 jem.rupress.org Downloaded from

Studies on Meningococcus Infection

“…The fact has already been noted (1,2) that the protein precipitable from Type I meningococcus autolysates by dilute acetic acid, the so called nucleoprotein P fraction, carries with it appreciable amounts of S I. This reaction has been utilized as the first step in isolating purified S I.…”

“…It was first observed that when the P fraction was precipitated by acidifying the broth to pH 4,0 with acetic acid in the presence of 1.5 volumes of ethyl alcohol, the S I present was removed almost quantitatively from solution (as shown by the precipitin test with Type I monovalent antimeningococcal serum(). Since the large 1 The precipitin test now used shows slight modifications from the method previously described (I). Tubes of about 3.5 ram.…”

Studies on Meningococcus Infection

“…Only Type I-III and Type II sera were used. Type IV serum was omitted since no strains of this type are being seen at this time and only an old stock strain was available for serum production (2); and Type III serum was not used since additional work has abundantly confirmed the opinion, given elsewhere (3), that there is no significant difference between Types I and III, so called, as they occur today. 0.1 cc.…”

Studies on Meningococcus Infection

“…Zozaya (5) has used what was p r o b a b l y the group-specific polysaccharide, or C substance, of the meningococcus as the precipitating antigen. The isolation from the T y p e I meningococcus of a highly purified, type-specific substance (6,7) (to be referred to hereafter as S I) suggested the possibility of accurate measurement of the precipitin content of T y p e I antimeningococcal sera by the quantitative method developed by Heidelberger and Kendall (8). This has been done and in addition the method has been applied in following the fractionation and purification of such sera.…”