Genotyping of Coxiella burnetii isolates in Iran using Multiple-locus variable-number tandem repeat analysis (MLVA).

INTRODUCTION: Coxiella burnetii is the etiological agent of Q fever, a zoonotic infection recognized in various regions of Iran. Despite its significance, few studies have focused on determining C. burnetii genotypes in Iran. This study aimed to assess the genetic diversity of C. burnetii in Iran using the Multiple-Locus Variable-Number Tandem Repeat Analysis (MLVA) method. METHODS: A total of 26 C. burnetii-positive specimens were selected from a repository of 119 specimens collected from various locations across Iran. These samples were previously identified as C. burnetii using nested PCR and TaqMan real-time PCR techniques. In this study, the MLVA method was utilized for genotyping C. burnetii isolates. RESULTS: Genotyping results from the 26 C. burnetii-positive samples indicated that nearly all loci were informative for genotyping, except two loci (ms23 and ms26). Cluster analysis of the MLVA profiles identified 13 clusters, along with 40 singleton genotypes. Iranian isolates were distributed across a single cluster (Cluster 13), which consisted exclusively of Iranian strains, and 24 unique singleton genotypes, highlighting the genetic diversity of C. burnetii circulating within the region. DISCUSSION AND CONCLUSION: The genotypic characteristics of C. burnetii observed in Iran differed significantly from those found in other global regions, suggesting unique local adaptations of this microorganism. To enhance our understanding of the epidemiology of Q fever in Iran, further large-scale studies are required to evaluate the distribution of C. burnetii genotypes across various geographic areas, host species, and environmental reservoirs.