Loss of TSS1 in hypervirulent Coxiella burnetii 175, the causative agent of Q fever in French Guiana

Comp Immunol Microbiol Infect Dis. 2015 Aug:41:35-41. doi: 10.1016/j.cimid.2015.04.003. Epub 2015 May 7.

Abstract

In French Guiana, the unique Coxiella burnetii circulating genotype 17 causes 24% of community-acquired pneumonia, the highest prevalence ever described. To explain this unusual virulence, we performed a comparative genomic analysis of strain Cb175, which was isolated from a patient from French Guiana. Cb175 has a greater number of mutations in genes involved in metabolism compared with the Nine Mile I strain. We found a 6105bp fragment missing in Cb175, which corresponds to the Type 1 secretion systems (T1SS) hlyCABD operon region. This deletion was detected by a specific qPCR in the 8 other strains available from this territory an in none of 298C.burnetii strains from other areas and other genotypes (8/8 vs 0/298, Fisher's exact test, p<0.0000001). Loss of genes implicated in secretion systems has been observed in other epidemic bacterial strains. Thus, the virulence of Cb175 may be linked to this genome reduction.

Keywords: Cb175; Coxiella burnetii; Guiana.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Coxiella burnetii / genetics*
  • Coxiella burnetii / isolation & purification
  • Coxiella burnetii / pathogenicity*
  • French Guiana
  • Gene Deletion*
  • Genetic Variation
  • Genome, Bacterial
  • Genotype
  • Humans
  • Mutation
  • Operon
  • Prevalence
  • Q Fever / microbiology*
  • Real-Time Polymerase Chain Reaction
  • Type I Secretion Systems / genetics*
  • Virulence

Substances

  • Type I Secretion Systems