Genomic pattern analysis of Burkholderia mallei field isolates by pulsed-field gel electrophoresis (PFGE) discriminatory typing

Background and Objectives: Glanders is a serious zoonotic disease caused by Burkholderia mallei. Prevention, control, and treatment strategies of glanders are prerequisites for microbial source tracking. The present study was aimed to analyze the genomic pattern of B. mallei Iranian field isolates by pulsed-field gel electrophoresis (PFGE) typing. Materials and Methods: B. mallei isolates were aerobically cultured in nutrient broth/agar supplemented with glycerol 4% for 48 h at 37°C. API 20NE identification system was used for the biochemical characterization. Genomic DNA of bacterial isolates was extracted using OIE-recommended protocol. Molecular identification of bacterial isolates was done based on amplification of BimA and IS407-flip genes. PFGE was applied to prepare the genomic pattern of B. mallei isolates. The guinea pig was used as a suitable model for studying the histopathological characterization of B. mallei. Results: In both enzymatic digestion patterns by using Af1II and VspI, we found three different clonal types; І) PFGE type of B. mallei Razi 325 strain, ІІ) PFGE type of Tiger, Kordan, and Oshnavieh strains, and ІІІ) PFGE type of Semirom strain. B. mallei Razi 325 was categorized as unrelated strain which was belonged to the different cluster differing more than four bands. Conclusion: PFGE showed more discriminatory power and considerable reproducibility for molecular typing of B. mallei strains in our study. It is standardized the approaches for outbreak detection, pathogen phylogeny, molecular epidemiology, and population studies