Table 1.
Bacterial strain panel used in this study.
Figure 1.
Colony morphologies of various B. pseudomallei near-neighbour species on Ashdown’s agar.
Panels: A, Burkholderia ubonensis MSMB700; B, B. ubonensis MSMB704; C, B. ubonensis MSMB1138; D, B. ubonensis MSMB718; E, B. ubonensis MSMB1191; F, B. ubonensis MSMB1165; G, B. ubonensis MSMB1202; H, Pandoraea sp. MSMB824; I, Herbaspirillum seropedicae MSMB1000; J, Burkholderia diffusa MSMB1075; K, Chryseobacterium sp. MSMB1448; L, Cupriavidus metallidurans MSMB1495; M, Burkholderia vietnamiensis MSMB1224; N, Burkholderia multivorans MSMB1271; O, Burkholderia pyrrocinia MSMB1147; P, Delftia sp. MSMB943; Q, Ralstonia mannitolilytica MSMB1253; R, Burkholderia thailandensis MSMB1415; S, Burkholderia cepacia MSMB1456; T, B. cepacia MSMB1011; U, Acidovorax caeni MSMB1260. On this medium, Burkholderia ubonensis demonstrates similar morphological characteristics to its potentially deadly near-neighbour, Burkholderia pseudomallei, including uptake of crystal violet and neutral red, and wrinkling of colonies after ∼72 h growth [13], [24]. Molecular genotyping is therefore necessary for differentiation of B. ubonensis from other bacterial species that grow on Ashdown’s medium. Note the morphological differences among B. ubonensis strains; several morphotypes have also been observed in B. pseudomallei [24].
Figure 2.
Bu550 B. ubonensis-specific real-time PCR.
Bu550 differentiates Burkholderia ubonensis from other soil- and water-borne bacterial species that grow on Ashdown’s agar [13]. Only B. ubonensis (shown in blue) amplifies with this assay. Other species (shown in red) fail to amplify.