Both BO2 and BO1T recA sequences are distanced by 8 and 11 unique SNPs, respectively, from the Brucella spp. recA consensus sequence, and share only one common transversion at the 517 nucleotide position. Translation of the recA gene sequences of BO1T, BO2 and the Brucella spp. consensus sequence shows that all base pair
changes were synonymous substitutions having no effect on protein structure or function. The Brucella outer membrane proteins have been studied extensively for their function in virulence, pathogenicity, bacteriophage reception, antigenic factors and antibacterial evasion [42–45]. The genetic variability among the omp genes within the Brucella spp. has proven effective at characterizing Brucella spp. and strain types and is often used for higher resolution molecular typing [4, 32, 43, 45]. PLX3397 The omp2a/2b genetic analysis we report here is very interesting in that BO2 consistently associates with not only BO1T but the atypical B. suis 83-210 strain that was isolated from a rodent in Australia ; and thus Selleck P005091 further investigation may be
warranted into rodents as a possible natural reservoir for these novel Brucella species. Investigation of the nine housekeeping genes by multi locus sequencing analysis demonstrates that BO2 is genetically distinct from BO1T yet exhibits remarkably similar divergence (1.5%) from the classical Brucella sequence types as shown in Figure 4. The relative similarity of the nucleotide
sequences of BO1T and BO2 by MLSA demonstrates uniquely distant sequence types within the currently characterized Brucella spp. and should be considered as a new group of STs within the Brucella genus. They also exhibit distinct allelic profiles by MLVA although all alleles in both the BO1T and BO2 allelic profiles have been observed in other Brucella spp. Furthermore, the phylogenetic analysis shown in Figure 5 demonstrates that these strains form a single separate cluster from the classical RG7420 datasheet Brucella spp. . The molecular and microbiological characteristics presented here provide supporting evidence that strain BO2 is most closely associated with the BO1T strain and should be considered as a novel lineage of B. inopinata sp. Attempting to understand the evolutionary origin of these two strains is somewhat confounded by the interesting and disparate medical histories of the case patients (who both happened to have lived in Portland, Oregon) from whom these strains were isolated and suggests that there are new and emerging Brucella strains capable of causing unusual presentation of human brucellosis. Conclusion Phenotypic and genomic analysis of the unusual Brucella strain (BO2) from a lung biopsy have established it as a lineage of the recently identified novel B. inopinata sp. type strain BO1T, which was isolated from a wound associated with a breast implant.