Burkholderia pseudomallei (B. pseudomallei)

Burkholderia pseudomallei is a Gram-negative, motile, aerobic rod-shaped bacterium endemic to tropical soils, where it thrives as a saprophyte in the rhizosphere.[1][3] It causes melioidosis, a severe infection transmitted via cutaneous, inhalation, or ingestion routes from contaminated environments, manifesting as pneumonia, abscesses (skin, bone, parotid, CNS), sepsis, or latent disease with reactivation years later.[1][7][9] Key virulence mechanisms include phagosomal escape via type III secretion system (T3SS-Bsa), actin-based motility (BimA protein) for cell-to-cell spread, multinucleated giant cell formation (T6SS-5), and immune evasion by capsule polysaccharides.[1][5] The bacterium exhibits intrinsic resistance to multiple antibiotics due to efflux pumps and low membrane permeability, complicating treatment which requires extended ceftazidime or carbapenem therapy followed by oral eradication.[1][2][3] Preclinical candidates like flucytosine and burkfloxacin show promise against intracellular spread, while host-targeted COX-2 inhibitors enhance macrophage killing.[2][4] As a Tier-1 Select Agent, it poses biothreat risks, driving research into novel antimicrobials targeting bacterial enzymes like D-alanine-D-alanine ligase.[2][6][12]

Other names

BpWhitmore's bacillus (historical name for the melioidosis agent)

Beta-lactams/glycopeptides target peptidoglycan biosynthesis (e.g., ceftazidime; BpDdl as potential target) Flucytosine acts as prodrug converted to 5-FU/FUMP, inhibiting intracellular growth (selectivity via bacterial CodA) Burkfloxacin inhibits intracellular replication and cell-cell spread (fluoroquinolone accumulation in host cells) Efflux pump inhibition counters intrinsic resistance to aminoglycosides, fluoroquinolones, macrolides