Genomic Fingerprinting of the Vaccine Strain of Clostridium Tetani by Restriction Fragment Length Polymorphism Technique

Background : Clostridium tetani or Nicolaier’s bacillus is an obligatory anaerobic, Gram-positive, movable with terminal or sub terminal spore. The chromosome of C. tetani contains 2,799,250 bp with a G+C content of 28.6%. The aim of this study was identification and genomic fingerprinting of the vaccine strain of C. tetani.
Materials and Methods : The vaccine strain of C. tetani was provided by Razi Vaccine and Serum Research Institute. The seeds were inoculated into Columbia blood agar and grown for 72 h and transferred to the thioglycolate broth medium for further 36 h culturing. The cultures were incubated at 35ºC in anaerobic conditions. DNA extraction with phenol/ chloroform method was performed. After extraction, the consistency of DNA was assayed. Next, the vaccine strain was digested using pvuII enzyme and incubated at 37ºC for overnight. The digested DNA was gel-electrophoresed by 1% agarose for a short time. Then, the gel was studied with Gel Doc system and transferred to Hybond N+membrane using standard DNA blotting techniques.
Results : The vaccine strain of C. tetani genome was fingerprinted by RFLP technique. Our preliminary results showed no divergence exists in the vaccine strain used for the production tetanus toxoid during the periods of 1990-2011.
Conclusion : Observation suggests that there is lack of significant changes in RFLP genomic fingerprinting profile of the vaccine strain. Therefore, this strain did not lose its efficiency in tetanus vaccine production. RFLP analysis is worthwhile in investigating the nature of the vaccine strain C. tetani.