CC BY-NC-ND 4.0 · J Lab Physicians 2023; 15(02): 276-281
DOI: 10.1055/s-0042-1760667
Original Article

Variable Virulence Genes in Clinical Isolates of Burkholderia pseudomallei: Impact on Disease Severity and Outcome in Melioidosis

Sruthi Raj
1   Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education & Research, Puducherry, India
Sujatha Sistla
1   Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education & Research, Puducherry, India
Deepthy Melepurakkal Sadanandan
2   Department of Biostatistics, Jawaharlal Institute of Postgraduate Medical Education & Research, Puducherry, India
Sreeram Chandra Murthy Peela
1   Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education & Research, Puducherry, India
› Author Affiliations
Funding This study was supported by the Jawaharlal Institute of Postgraduate Medical Education and Research (JIP/RES/INTRAMURAL/PHS1/2018-19) for conducting research.


Objectives To isolate Burkholderia pseudomallei from clinical specimens and study the association of virulence genes with clinical manifestations and outcome in patients with melioidosis.

Materials and MethodsBurkholderia pseudomallei isolates obtained from melioidosis cases diagnosed during 2018 to 2021 were identified using VITEK 2 system and confirmed by polymerase chain reaction (PCR) targeting a Type III secretion system gene cluster. Multiplex PCR was performed to detect the genotypes of lipopolysaccharide (LPS) namely A, B, and B2, and singleplex PCR was performed to detect the presence of the Burkholderia intracellular motility gene (BimA) and filamentous hemagglutinin gene (fhaB3).

Statistical Analysis Chi-square/Fisher's exact tests were performed to study the association between various clinical manifestations and outcome and different virulence genes. The results were expressed as unadjusted odds ratios with 95% confidence intervals.

Results Sixty-seven isolates were available for characterization. BimABm and BimABp were observed among 82 and 18% of the isolates, respectively. Both sepsis and mortality were significantly associated with BimABm . Majority of the isolates had fhaB3 (97%). Most of the isolates showed the presence of LPS A gene (65.7%) followed by LPS B gene (6%), while LPS B2 was not detected. Nineteen isolates could not be assigned to any LPS genotypes.

Conclusion Among the virulence genes studied, only BimABm was significantly associated with sepsis and mortality. More than a quarter (28.3%) of the isolates could not be assigned to any LPS genotypes, hinting at a greater genetic diversity in our isolates.

Ethical Approval

Approval was obtained from Institutional Ethics Committee (IEC) for Human Studies, JIPMER, Puducherry (JIP/IEC/2018/0230).

Supplementary Material

Publication History

Article published online:
18 January 2023

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  • References

  • 1 Gassiep I, Armstrong M, Norton R. Human Melioidosis. Clin Microbiol Rev 2020; 33 (02) e00006-e00019
  • 2 Shaw T, Tellapragada C, Kamath A, Kalwaje Eshwara V, Mukhopadhyay C. Implications of environmental and pathogen-specific determinants on clinical presentations and disease outcome in melioidosis patients. PLoS Negl Trop Dis 2019; 13 (05) e0007312
  • 3 Sarovich DS, Price EP, Webb JR. et al. Variable virulence factors in Burkholderia pseudomallei (melioidosis) associated with human disease. PLoS One 2014; 9 (03) e91682
  • 4 Anuntagool N, Wuthiekanun V, White NJ. et al. Lipopolysaccharide heterogeneity among Burkholderia pseudomallei from different geographic and clinical origins. Am J Trop Med Hyg 2006; 74 (03) 348-352
  • 5 Webb JR, Sarovich DS, Price EP, Ward LM, Mayo M, Currie BJ. Burkholderia pseudomallei lipopolysaccharide genotype does not correlate with severity or outcome in melioidosis: host risk factors remain the critical determinant. Open Forum Infect Dis 2019; 6 (04) ofz091
  • 6 Tellapragada C, Shaw T, D'Souza A, Eshwara VK, Mukhopadhyay C. Improved detection of Burkholderia pseudomallei from non-blood clinical specimens using enrichment culture and PCR: narrowing diagnostic gap in resource-constrained settings. Trop Med Int Health 2017; 22 (07) 866-870
  • 7 MBL3-8.0M. Standard Operating Procedure (SOP) for Isolation of Burkholderia pseudomallei from Clinical Samples Version 1.5. Mahidol Oxford Tropical Medicine Research Unit; 2015. Accessed March 06, 2018, at:
  • 8 Chantratita N, Wuthiekanun V, Boonbumrung K. et al. Biological relevance of colony morphology and phenotypic switching by Burkholderia pseudomallei. J Bacteriol 2007; 189 (03) 807-817
  • 9 Virk HS, Mukhopadhyay C, Wiersinga WJ. Melioidosis: a neglected cause of community-acquired pneumonia. Semin Respir Crit Care Med 2020; 41 (04) 496-508
  • 10 Wiersinga WJ, Virk HS, Torres AG. et al. Melioidosis. Nat Rev Dis Primers 2018; 4: 17107
  • 11 Sun GW, Gan YH. Unraveling type III secretion systems in the highly versatile Burkholderia pseudomallei . Trends Microbiol 2010; 18 (12) 561-568
  • 12 Tuanyok A, Stone JK, Mayo M. et al. The genetic and molecular basis of O-antigenic diversity in Burkholderia pseudomallei lipopolysaccharide. PLoS Negl Trop Dis 2012; 6 (01) e1453
  • 13 Arjcharoen S, Wikraiphat C, Pudla M. et al. Fate of a Burkholderia pseudomallei lipopolysaccharide mutant in the mouse macrophage cell line RAW 264.7: possible role for the O-antigenic polysaccharide moiety of lipopolysaccharide in internalization and intracellular survival. Infect Immun 2007; 75 (09) 4298-4304
  • 14 Norris MH, Schweizer HP, Tuanyok A. Structural diversity of Burkholderia pseudomallei lipopolysaccharides affects innate immune signaling. PLoS Negl Trop Dis 2017; 11 (04) e0005571
  • 15 Webb JR, Win MM, Zin KN. et al. Myanmar Burkholderia pseudomallei strains are genetically diverse and originate from Asia with phylogenetic evidence of reintroductions from neighbouring countries. Sci Rep 2020; 10 (01) 16260
  • 16 Arushothy R, Amran F, Samsuddin N, Ahmad N, Nathan S. Multi locus sequence typing of clinical Burkholderia pseudomallei isolates from Malaysia. PLoS Negl Trop Dis 2020; 14 (12) e0008979
  • 17 Tuanyok A, Leadem BR, Auerbach RK. et al. Genomic islands from five strains of Burkholderia pseudomallei . BMC Genomics 2008; 9: 566