Novel Species of Brucella Causing Human Brucellosis, French Guiana

Abstract

Human brucellosis is a zoonoses caused by bacteria of the genus Brucella. Infection results in subacute or chronic debilitating disease with nonspecific clinical manifestations and is often associated with consuming unpasteurized dairy products. We report 2 cases of brucellosis in male patients who were hospitalized in distinct towns of French Guiana, an overseas territory of France located on the northeastern shore of South America. Both men were citizens of Brazil working as clandestine goldminers in the deep Amazonian rainforest. Characterization of the 2 bacterial isolates revealed that they represent a potential new species of Brucella. Medical practitioners working in contact with wildlife in this region of the world should be aware of the existence of these pathogens and the potential for human infection.

Keywords: Brucella; French Guiana; bacteria; brucellosis; zoonoses.

Figure 1

Locations of main towns and care facilities in French Guiana.

Figure 2

PCR typing of newly discovered Brucella isolates obtained from 2 patients in French Guiana, 2020. Genomic DNA from bacterial isolates BRSO-2020-213 and BRSO-2021-230 (numbers in bold) were used as a template for Bruce-Ladder (5) (A) or Suis-Ladder (6) (B) multiplex PCR. The profiles obtained after agarose gel electrophoresis were compared with the profile of type strains 16M (Brucella melitensis), 2308 (B. abortus), 1330 (B. suis bv1), Thomsen (B. suis bv2), 686 (B. suis bv3), 40 (B. suis bv4), 513 (B. suis bv5), RM6/66 (B. canis), Rev1 (B. melitensis vaccine strain), F8/08–60 (B. papionis), CCM 4915 (B. microti), or 5K33 (B. neotomae). Molecular-weight size markers in bp are shown at left. bv, biovar; Ø, negative control.

Figure 3

Phylogenetic placement of Brucella isolates BRSO-2020-213 and BRSO-2021-230 from 2 patients diagnosed with brucellosis in French Guiana, 2020. A genome-based tree was constructed by using a selection of reference Brucella genomes (Appendix Table) on the PATRIC platform (BRC NIAID Bioinformatics Resource Centers, https://www.bv-brc.org). The number of compared genes was fixed at 1,000, and all other parameters were set by default. Scale bar indicates number of substitutions per site.

Figure 4

Phylogenetic placement of Brucella isolates BRSO-2020-213 and BRSO-2021-230 from 2 patients diagnosed with brucellosis in French Guiana, 2020, using alignments of Brucella genes. Sequences of the genes recA, 16S rRNA, and omp2b were aligned using the web tool Phylogeny (17) using the default parameters (“One Click” mode). Scale bar indicates number of substitutions per site.