title: The role of 'atypical' Brucella in amphibians: are we facing novel emerging pathogens?
abstract: OBJECTIVE
  To discuss together the novel cases of Brucella infections in frogs with the results of published reports to extend our current knowledge on 'atypical' brucellae isolated from amphibians and to discuss the challenges we face on this extraordinary emerging group of pathogens.
  
  
  RESULTS
  Since our first description, an additional 14 isolates from four different frog species were collected. Novel isolates and a subset of Brucella isolates previously cultured from African bullfrogs were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), Fourier transform-infrared (FT-IR) spectroscopy and broth microdilution susceptibility testing. MALDI-TOF MS worked very efficiently for an accurate bacterial identification to the genus level. Within the cluster analysis, 'atypical' brucellae grouped distant from Brucella melitensis and were even more separated by FT-IR spectroscopy with respect to their geographical origin. Minimum inhibitory concentrations of 14 antimicrobial substances are provided as baseline data on antimicrobial susceptibility.
  
  
  CONCLUSIONS
  The case history of Brucella infections in amphibians reveals a variety of pathologies ranging from localized manifestations to systemic infections. Some isolates seem to be capable of causing high mortality in zoological exhibitions putting higher demands on the management of endangered frog species. There is considerable risk in overlooking and misidentifying 'atypical' Brucella in routine diagnostics.
  
  
  CONCLUSIONS
  Brucella have only recently been described in cold-blooded vertebrates. Their presence in frog species native to Africa, America and Australia indicates a more common occurrence in amphibians than previously thought. This study provides an extensive overview of amphibian brucellae by highlighting the main features of their clinical significance, diagnosis and zoonotic potential.
authors.affiliation: Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Mühldorfer
authors.affiliation: Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Wibbelt
authors.affiliation: Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany.
authors.forename: C A
authors.initials: CA
authors.lastname: Szentiks
authors.affiliation: Clinic for Birds, Reptiles, Amphibians and Fish, Justus Liebig University Giessen, Giessen, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Fischer
authors.affiliation: Bundeswehr Institute of Microbiology, German Center for Infection Research (DZIF), Munich, Germany.
authors.forename: H C
authors.initials: HC
authors.lastname: Scholz
authors.affiliation: Hessian State Laboratory (LHL), Giessen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Zschöck
authors.affiliation: Hessian State Laboratory (LHL), Giessen, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Eisenberg
mesh_terms: D000663:Amphibians; D000818:Animals; D001315:Australia; D002002:Brucella / Q000145:classification* / Q000187:drug effects / Q000302:isolation & purification* / Q000502:physiology; D002006:Brucellosis / Q000453:epidemiology / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D016000:Cluster Analysis; D006801:Humans; D008826:Microbial Sensitivity Tests; D010802:Phylogeny; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D017550:Spectroscopy, Fourier Transform Infrared; D015047:Zoonoses
keywords: 
  Brucella
  ; MALDI-TOF MS; animal health; bacteria; frog; infectious disease; zoonosis