Preparation of polyclonal antibody in rabbit against Neisseria meningitidis serogroup A and C antigens used in diagnostic kits

Introduction and Objectives: Neisseria meningitidis (or meningococci) is a major cause of disease such as meningitis and meningococcemia and it is one of the leading causes of mortality in children in developed countries. Meningococci is classified to 13 serogroups according to serological specificities of their capsular antigens. Serogroups A, B, C, Y, and W135 are responsible for virtually all cases of the human disease. Bacterial identification early in the course of diseases could lead to selection of appropriate antimicrobial therapy and indicate the need for specific immunization for prevention. The purpose of this study was to produce antiserum against meningococcal antigens for use in different diagnostic kits, like agglutination, Elisa and immunofluorescence (IF). Materials and Methods: New Zealand white rabbits were immunized by intravenous injections of an inactivated suspension of the bacteria adjusted to a cell density equivalent to a turbidity of a McFarland number 3standard. Serum was collected one week after last injection. Results: The bacterial agglutination test was performed and results showed high quality and quantity of antibody. Furthermore, antibody purification steps were done by using precipitation, filtration and ion exchange chromatography methods. The purity was confirmed by SDS-Page electrophoresis and purified antibody could be used in Elisa and IF tests. Conclusion: Agglutination tests has always been very popular due to low cost and feasibility of the method. In addition, high purity antibody can be used in clinical diagnosis and serologic identification based on Elisa and IF, where sensitivity and specificity are important issues.

Keywords:

Neisseria meningitidis , Antiserum , Agglutination , Elisa and immunofluorescence