0296 (P = 0.025), indicating a linkage disequilibrium which disappeared when the analysis was repeated with each RT treated as an individual (P > 0.05), suggesting a possible epidemic population structure in which occasional clones emerge and spread. Considering each bacterial population according to its geographic origin, a random association among the alleles (linkage equilibrium) within the Italian B. cenocepacia IIIB population was found either when all isolates or each RT treated as an individual were considered (P > 0.05); conversely,
BTSA1 purchase the Mexican B. cenocepacia IIIB population showed linkage disequilibrium at both levels (Table 3). Linkage disequilibrium was also observed within the Italian
BCC6 population when all 53 isolates were considered ( ; P = 0.0002); conversely, when the analysis was restricted to RTs taken as units, linkage equilibrium was found ( ; P > 0.05). Within the Mexican BCC6 Cilengitide maize rhizosphere population, linkage equilibrium was found either when all isolates or RTs taken as units were considered (P > 0.05). Discussion In this study, 96 isolates belonging to the species B. cenocepacia IIIB and the BCC6 group, recovered from maize rhizosphere in Italy and Mexico, were characterized by using MLRT, in order to investigate the genetic diversity and relationships of bacteria associated with maize cultivated in geographically distant locations. Despite the clear relationship found between the geographic origin of isolates and grouping, identical RTs and closely related isolates were observed in geographically distant regions (Mexico and Italy). Two main complexes were identified following eBURST analysis, namely RT-4 for B. cenocepacia IIIB and RT-104 for BCC6. These two main clonal complexes included RTs shared by both Italian and Mexican maize rhizospheres, suggesting some mixing of the genotypes between the two continental regions and KPT-8602 price excluding the possibility of any kind of geographic subspeciation in the formation of these two complexes. At the genus and species level, Acetophenone many prokaryotes have a cosmopolitan distribution
in their respective habitats and the same genotypes have often been identified in similar habitats in different geographic areas . The wide geographic distribution and substantial capability of Burkholderia spp. to colonize diverse host plants was observed in distantly separated environments [21, 24], as well as genetic identity between BCC isolates of clinical and environmental origins recovered from different countries has been proved . Grouping isolates by eBURST analysis is useful to better evaluate the RTs distribution in natural population where highly similar RTs are found, i.e. to elucidate the meaning of the presence of closely related strains in geographically separated maize rhizospheres in respect to niche specificity and adaptation.