Factors associated with genotype clustering of Mycobacterium tuberculosis isolates in an ethnically diverse region of southern California, United States

► We evaluate genotypes of Mycobacterium tuberculosis isolates in a multinational community in US. ► Cluster analyses show isolates represent diverse mix of globally prevalent lineages. ► Almost half of TB cases are likely due to direct transmission. ► Clonal complexes indicate TB is being transmitted in insular community networks.