Genomic fingerprinting of the vaccine strain of clostridium tetani by restriction fragment length polymorphism technique

Clostridium tetani or Nicolaier's bacillus is an obligatory anaerobic, Gram-positive, movable with terminal or sub terminal spore. The chromosome of C. tetanicontains 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. 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 35[degree]C 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 37[degree]C 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. 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. 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

Genetic structure change in harvard vaccine strain of clostridium tetani for the period of 1990 to 2010 by pulsed-field gel electrophoresis

PFGE facilitates the differential migration of large DNA fragments through agarose gel by constantly changing the direction of the electrical field during electrophoresis. Possibility of high difference between strains and repeatability make PFGE one of the strong molecular methods in study of bacterial strains in epidemiology. To identifying and DNA fingerprinting of vaccine strain of Clostridium tetani by PFGE technique. Also, possibility of genotyping profile changes in frequency of vaccine strain of C. tetani during the period of 1990 to 2011. The vaccine strain of C. tetani was provided by Razi Vaccine and Serum Research Institute in Karaj. The seeds were inoculated into Columbia blood agar and grown for 72 h. The cultures were incubated at 35[degree]C in anaerobic conditions. The PFGE analyses were performed using genomic DNA digested with the restriction enzyme SmaI. The electrophoresis analyses were carried out on a CHEF DR III apparatus [Bio Rad] and band patterns obtained were then analyzed. The PFGE profile obtained from vaccine strain during a period of more than two decades revealed no remarkable genetic changes and mutations. This type of analysis provides detailed data useful for surveillance of vaccine strains and isolates as well as for the selection of certain predominant profiles for further investigation. This study showed no considerable change in chromosomal genome of Harvard, the vaccine strain. It is therefore concluded that the vaccine produced by Razi Institute had evidently no alteration or modification in accordance to PFGE profile analysis during a period of more than two decades

Evaluation of relative potency of human tuberculin skin test in the guinea pigs sensitized with mycobacterium tuberculosis, M. bovis BCG and M. avium

The tuberculin skin test is the most commonly used test for diagnosing tuberculosis [TB] infection. The basis of tuberculin testing is the induction of a delayed hypersensitivity reaction to the intradermal injection of tuberculin. Unfortunately, this test is incapable of distinguishing Mycobacterium tuberculosis infection from Bacille Calmette-Guerin [BCG] vaccination or infection with non-tuberculous mycobacteria. The aim of this study is to evaluate the relative potency of human tuberculin skin test] produced by Razi Vaccine and Serum Research Institute [in the guinea pigs sensitized with M. tuberculosis, M. bovis BCG and M. avium. For skin test, different groups of guinea pigs were sensitized with M. tuberculosis, M. avium and M. bovis BCG. Guinea pigs were injected intradermally with 0.1 ml of 0.4, 2 and 10 micro g/ml of tuberculin. Skin reactions [diameters of erythema, in millimeters] were independently measured 24 h after injection and results were calculated. The results showed that the specificity index of human tuberculin test for guinea pigs sensitized with M. bovis BCG in compare of guinea pigs sensitized with M. tuberculosis was equal and for guinea pigs sensitized with M. avium was not equal. This study demonstrated that human tuberculin test produced by Razi Institute for diagnosis of latent infection to M. tuberculosis has lower specificity for M. bovis in comparison with M. avium