BALB/c and C57Bl/6 Mice Infected With Virulent Burkholderia Pseudomallei Provide Contrasting Animal Models for the Acute and Chronic Forms of Human Melioidosis

Microb Pathog. 1998 May;24(5):269-75. doi: 10.1006/mpat.1997.0179.

Abstract

Burkholderia pseudomallei is the aetiological agent of melioidosis, a life-threatening bacterial disease occurring in many species of animals, including man. Infection in humans commonly manifests as one of three clinical presentations: acute, subacute or chronic disease. Investigations were undertaken to assess the suitability of BALB/c and C57Bl/6 mice as animal models for the different forms of human melioidosis. The course of infection in BALB/c mice was similar to that which occurs in acute human infection. By contrast, infection of C57Bl/6 mice appeared to mimic chronic human melioidosis. While BALB/c mice suffered a rapidly-progressive bacteraemia which resulted in host death by 96 h, C57Bl/6 mice were able to prevent this, and typically remained asymptomatic for up to 6 weeks. LD50 values of 4 cells and 2.5 x 10(4) cells for BALB/c and C57Bl/6 mice, respectively, reflect these observations. The heightened level of resistance to B. pseudomallei observed in C57Bl/6 mice was suggested to have a genetic basis, when the susceptibilities of first filial and reciprocal backcross generations were examined. Growth kinetics of B. pseudomallei within BALB/c and C57Bl/6 peritoneal exudate cell (PEC) cultures were examined to investigate PEC microbicidal efficiency as a determinant of host susceptibility. C57Bl/6 PEC cultures exhibited greater microbicidal efficiency towards B. pseudomallei when compared to BALB/c cells, indicating that susceptibility may be determined by non-specific, cellular mechanisms. Collectively, these results suggest that the BALB/c and C57Bl/6 strains of mice may provide excellent models for acute and chronic human melioidosis, respectively.

MeSH terms

  • Animals
  • Burkholderia pseudomallei / pathogenicity*
  • Colony Count, Microbial
  • Disease Models, Animal*
  • Female
  • Humans
  • Lethal Dose 50
  • Male
  • Melioidosis / microbiology*
  • Melioidosis / pathology
  • Mice
  • Mice, Inbred BALB C / microbiology*
  • Mice, Inbred C57BL / microbiology*