Genetic analysis of clinical and vaccine strains of Bordetella pertussis by Pulsed-Field Gel Electrophoresis (PFGE), Multi Locus Sequence Typing (MLST) and serotyping

Anahita Bahmanjeh¹ Zahra Hosseini Moorderaz² Elham Ghasemi³ Cobra Tofighi⁴ Amir Azizi⁵ Zolfaghar Zolfaghari⁶ Seyed Mohammad Ghorbani Dazmiri⁷

1) Department of Virology Vaccines, Production and Research Unit, Pasteur Institute of Iran, Karaj, Iran
2) Department of Biology, Faculty of Biological Sciences, Yasuj Branch, Islamic Azad University, Yasuj, Iran
3) Department of Biology, Faculty of Sciences, Urmia University, Urmia, Iran
4) Department of Biological Sciences, Danesh Alborz University, Abyek, Qazvin, Iran
5) Department of Biology, Tonekabon Branch, Islamic Azad University, Tonekabon, Iran
6) Department of Biotechnology, Faculty of Biological Sciences, Islamic Azad University-Mashhad Branch(IAUM), Iran
7) Faculty of Biological Sciences, Sari Branch, Islamic Azad University, Sari, Iran

Publication : 2nd International Congress on Science, engineering & New Technologies(secongress.com)
Abstract :
In spite of high vaccination coverage in the Expanded Program of Immunization (EPI), pertussis has not been eradicated yet and the re-emergence of the disease is still reported worldwide. The genetic divergence study of circulating clinical strains of Bordetella pertussis among the population with high vaccination coverage is a useful tool to have an insight in the understanding of genetic patterns of this bacterium and deviation of them from vaccine strains. Different methods are accessible for studying of Bordetella pertussis that can perform appropriate assessment between populations. Strains used in this study were a collection of two pertussis vaccine strains used to create killed pertussis vaccine over years at Razi Vaccine and Serum Research Institute, 10 clinical and 2 reference strains (ATCC9797 and Tohama I) in Multi locus Sequence Typing (MLST), Pulsed-Field Gel Electrophoresis (PFGE), and serotyping. The genetic profiles of vaccine working and master seeds showed no important change(s) in frequencies of fingerprint types investigated in the vaccine strains and had homogeneity in PFGE method where the clinical isolates showed diversity in genetic profile. Serotyping method showed that all of 10 clinical strains expressing Fim 3. In MLST study, seven housekeeping genes including adk, pgm, fum C, tyr B, gly A, pep A and icd were analyzed which showed no changes in the sequence of clinical and vaccine strains with 100% homology. The genes that cause pathogenicity like ptxC, tcfA and fhaB were also evaluated and the results illustrated heterogeneity in the vaccine and circulating strains.
Keywords : Bordetella pertussis Electrophoresis Serotyping Multi locus Sequence Typing