Evaluation of the antiserum agar method for the serogroup identification of Neisseria meningitidis

Abstract

The antiserum agar method (ASA), which is based on the formation of immunoprecipitates around bacterial growth on agar containing meningococcal hyperimmune horse serum, was evaluated for serogroup identification of Neisseria meningitidis. Four hundred meningococcal stains were serogrouped by ASA employing horse antisera to serogroups A, B, C, Y, W135, Z, and 29E and compared to serogroup identification by bacterial slide agglutination (BA) employing rabbit antisera. Overall, there was 95% agreement between the two methods. The ASA proved to be more accurate than BA since 15 strains which cross-reacted with Y and W135 rabbit antisera by BA were specifically serogrouped as either Y or W135 by ASA. In addition, 5 out of 75 strains which were ungroupable by BA were serogrouped as either B or 29E by ASA. Repeat serogroup identification of 100 meningococcal strains by ASA provided identical results thus showing the reproducibility of the method. The ASA is advantageous to BA since it is more reliable, utilizes standard antisera which do not have to be absorbed to remove cross-reactions, does not require the preparation of standardized bacterial antigen, and is simple to perform.

Invasive Potential of Nonencapsulated Disease Isolates of Neisseria meningitidis

“…Serogroup determination was done by standard bacterial agglutination test (22) using rabbit antisera against all 13 serogroups (A, B, C, D, H, I, K, L, W135, X, Y, Z, and 29E) (2). Detection of serogroups A, B, C, W135, X, Y, Z. and 29E by PCR was accomplished using primers and PCR conditions described by Borrow and colleagues (in 1997 and 1998), Taha (in 2000), and Bennett et al (in 2004) (3)(4)(5)32).…”

Serological Specificities of Murine Hybridoma Monoclonal Antibodies againstNeisseria meningitidisSerogroups B, C, Y, and W135 and Evaluation of Their Usefulness as Serogrouping Reagents by Indirect Whole-Cell Enzyme-Linked Immunosorbent Assay

“…Rabbit antisera to the capsular polysaccharide antigens of serogroups A, B, C, W135, X, Y, Z, and 29E were produced according to the method described by Ashton et al (2). Albino rabbits were immunized by intravenous injections of a viable suspension of the bacteria adjusted to a cell density equivalent to a turbidity of a McFarland number 3 standard.…”

“…The bacterial agglutination test to determine the serogroup identity of meningococci was done as described by Ashton et al (2).…”

Structural determination of the group K capsular polysaccharide of Neisseriameningitidis: a 2D-NMR analysis

“…The capsular polysaccharide was isolated and partially purified as previously described (14) using an initial Cetavlon precipitation to obtain the crude polysaccharide. Purification of the K polysaccharide was achieved by its application to a column of DEAE-Sephadex A-25 (C1-form, Pharmacia Fine Chemicals) in 0.01 M Tris-HC1 buffer at pH 7.4 and the development of the column with a linear gradient of NaCl to 0.5 M. The plysaccharide was detected by Ouchterlony immunodiffusion using antisera to the K polysaccharide that were prepared by injecting whole group K organisms in rabbits as previously described (15). Using this assay it was shown that the K polysaccharide eluted as a single peak with approximately 0.3 M NaCI.…”