BimA_Bm positivity in melioidosis and its impact on clinical profile, and outcomes: a retrospective cohort study

Objectives: Melioidosis, caused by Burkholderia pseudomallei presents with diverse clinical features. Neurological involvement, though rare, is a severe complication. The BimA_Bm allele, a variant of the Burkholderia intracellular motility A (BimA) virulence gene, has been linked to neurotropism, but data from India on this association are limited. Methods: We conducted a retrospective cohort study of 138 culture-confirmed melioidosis patients at a tertiary care center in southern India. A polymerase chain reaction assay was used to detect the BimA_Bm allele in archived isolates. Clinical features and 28-day mortality were compared between BimA_Bm -positive and -negative groups. Results: The BimA_Bm allele was detected in 5.8% of isolates. Neurological involvement was significantly more common in BimA_Bm-positive patients (50% [4/8] vs 2.3% [3/130], P < 0.001). No significant differences in comorbidities or 28-day mortality were observed between the two groups. Conclusions: Although uncommon, the BimA_Bm allele is strongly associated with neurological melioidosis in southern India.