Identification of an unusual Brucella strain (BO2) from a lung biopsy in a 52 year-old patient with chronic destructive pneumonia

Rebekah V Tiller,Scott C Bell,Jay E Gee,Amy V Jennison,Chris Coulter,John Bates,Sonali Gribble,Barun K De,David R Lonsway,Alex R Hoffmaster

doi:10.1186/1471-2180-10-23

Abstract

BackgroundBrucellosis is primarily a zoonotic disease caused by Brucella species. There are currently ten Brucella spp. including the recently identified novel B. inopinata sp. isolated from a wound associated with a breast implant infection. In this study we report on the identification of an unusual Brucella-like strain (BO2) isolated from a lung biopsy in a 52-year-old patient in Australia with a clinical history of chronic destructive pneumonia.ResultsStandard biochemical profiles confirmed that the unusual strain was a member of the Brucella genus and the full-length 16S rRNA gene sequence was 100% identical to the recently identified B. inopinata sp. nov. (type strain BO1T). Additional sequence analysis of the recA, omp2a and 2b genes; and multiple locus sequence analysis (MLSA) demonstrated that strain BO2 exhibited significant similarity to the B. inopinata sp. compared to any of the other Brucella or Ochrobactrum species. Genotyping based on multiple-locus variable-number tandem repeat analysis (MLVA) established that the BO2 and BO1Tstrains form a distinct phylogenetic cluster separate from the other Brucella spp.ConclusionBased on these molecular and microbiological characterizations, we propose that the BO2 strain is a novel lineage of the newly described B. inopinata species.

Highlights

Brucellosis is primarily a zoonotic disease caused by Brucella species
Hydrogen sulfide production by the BO2 strain was observed by the development of a dark gray color on lead acetate paper suspended above the heart infusion agar slant
The omp2a/2b genetic analysis we report here is very interesting in that BO2 consistently associates with BO1T but the atypical B. suis 83-210 strain that was isolated from a rodent in Australia [32]; and further investigation may be warranted into rodents as a possible natural reservoir for these novel Brucella species

Summary

Introduction

Brucellosis is primarily a zoonotic disease caused by Brucella species. There are currently ten Brucella spp. including the recently identified novel B. inopinata sp. isolated from a wound associated with a breast implant infection. Brucellosis is primarily a zoonotic disease, caused by members of the genus Brucella, which currently constitutes several species based on pathogenicity, host preferences and phenotypic characteristics: B. abortus (cattle), B. canis (dogs), B. melitensis (goats), B. suis (pigs), B. ovis (rams), B. neotomae (desert rats), B. ceti and B. pinnipedialis (marine mammals), and B. microti (common vole) [1,2,3,4,5,6]. Brucellosis in humans is mostly caused by B. abortus, B. melitensis, B. suis, and sometimes B. canis [14,17,18,19], and is commonly associated with the consumption of unpasteurized dairy products, meat from infected animals and exposure to infected animal tissues or laboratory transmission [1,2,20]. Most pulmonary brucellosis cases were found in farmers handling infected meat or travelers who consumed raw infected animal meat or unpasteurized milk products while visiting countries endemic for brucellosis [26,27]

Methods

Results

Discussion

Conclusion