Novel Brucella Strain (BO1) Associated with a Prosthetic Breast Implant Infection

Abstract

We report the microbiological, biochemical, and molecular characterization of an unusual Brucella strain (BO1) isolated from a breast implant wound in a 71-year-old woman with clinical symptoms consistent with brucellosis. Initial phenotypic analysis, including biochemical and antimicrobial susceptibility testing, cellular fatty acid analysis, and molecular analysis based on DNA-DNA reassociation and the presence of multiple copies of IS711 element suggested that the isolate was a Brucella-like organism, but species determination using microbiological algorithms was unsuccessful. Furthermore, molecular data based on 16S rRNA gene sequencing and multilocus sequence analysis demonstrated that BO1 was an unusual Brucella strain and not closely related to any currently described Brucella species. However, comparison with equivalent sequences in Ochrobactrum spp. confirms that the isolate is much more closely related to Brucella than to Ochrobactrum spp., and thus the isolate likely represents an atypical and novel strain within the genus Brucella.Brucellosis is primarily a zoonotic disease caused by members of the genus Brucella, which consists of six recognized species based on pathogenicity and host preferences: Brucella abortus (cattle), Brucella canis (dogs), Brucella melitensis (goats or sheep), Brucella suis (swine), Brucella ovis (rams), and Brucella neotomae (desert rats), as well as recently identified strains from marine mammals (5,10,13,26,34). Early studies on genomic DNA hybridization demonstrate a high degree of homology among the brucellae (40) and thus suggest the genus Brucella as one species, Brucella melitensis with several biovars (14), which has been confirmed by a number of molecular approaches, including 16S rRNA gene sequencing (21), multilocus enzyme electrophoresis (19), and whole-genome sequence analyses (15,24,36). However, because of the lack of widespread support the Brucella Taxonomy Subcommittee has recently returned to the traditional classification of the six Brucella nomenspecies with recognized biovars, along with two presumptive Brucella spp. from marine mammals: B. cetaceae and B. pinnipediae (34). Brucellae are intracellular facultative pathogens that infect many organs and soft tissues, including mammary glands, and frequently result in abortion, low milk production, and fetal death in animals (12,45).Most human disease is caused by B. abortus, B. suis, B. melitensis, and B. canis (13,22,35) and is most frequently associated with the consumption of unpasteurized dairy products or direct contact with infected animals or animal products (38,46). Brucellosis is also an occupational hazard of laboratory scientists infected by the inhalation of aerosols in a microbiology laboratory setting (32, 37). In humans, brucellosis is a systemic, febrile illness and can be associated with chronic debilitating infection of major organ systems that may include bone and the kidney, brain, epididymis, liver, ovary, and gallbladder (7,8,18,27). However, association of Brucella with infection of m...

Comparative Phylogenomics and Evolution of the Brucellae Reveal a Path to Virulence

“…There is also a clear separation between the "classical" Brucella species that are united in a core clade and a second group that diverged earlier. This early diverging basal group contains strains from Australian rodents (83/13 and NF2653) and two recent atypical human isolates, BO1 and BO2, where the natural host is unknown (27,28). Of the 193,760 shared SNPs within the overall phylogeny, Brucella species are separated from the two Ochrobactrum species by 158,016 SNPs.…”

Brucella vulpis sp. nov., isolated from mandibular lymph nodes of red foxes (Vulpes vulpes)

“…microti was initially isolated from the common vole, Microtus arvalis (Hubálek et al, 2007;Scholz et al, 2008a), and subsequently isolated from red foxes (Scholz et al, 2009) and directly from soil (Scholz et al, 2008b). Only one strain of B. inopinata has been isolated, recovered from a breast-implant infection of a 71-year-old woman with a clinical picture consistent with brucellosis (De et al, 2008;Scholz et al, 2010). Because of their high metabolic activity, B. microti and B. inopinata are commonly misidentified as Ochrobactrum in commercially available biochemical test systems such as API 20NE (bioMérieux).…”

Novel IS 711 Chromosomal Location Useful for Identification of Marine Mammal Brucella Genotype ST27, Which Is Associated with Zoonotic Infection

“…Brucella microti, first described in 2008, was isolated initially from the common vole but later also from the red fox and from soil (21)(22)(23). The latest species is B. inopinata, which was isolated from a human breast implant infection and represents the most distant Brucella species at the phenotypic and molecular levels relative to the others (10,24). The animal or environmental reservoir of the latter species is not known.…”