Characterization of aBrucellasp. Strain as a Marine-Mammal Type despite Isolation from a Patient with Spinal Osteomyelitis in New Zealand

Naturally acquired infection of humans with a marine mammal-associatedBrucella sp. has only been reported once previously in a study describing infections of two patients from Peru. We report the isolation and characterization of a strain ofBrucella from a New Zealand patient that appears most closely related to strains previously identified from marine mammals. The isolate was preliminarily identified asBrucella suis using conventional bacteriological tests in our laboratory. However, the results profile was not an exact match, and the isolate was forwarded to four international reference laboratories for further identification. The reference laboratories identified the isolate as eitherB. suis orB. melitensis by traditional bacteriological methods in three laboratories and by a molecular test in the fourth laboratory. Molecular characterization by PCR, PCR-restriction fragment length polymorphism, and DNA sequencing of thebp26 gene; IS711 ; theomp genesomp25 ,omp31 ,omp2a , andomp2b ; IRS-PCR fragments I, III, and IV; and five housekeeping gene fragments was conducted to resolve the discrepant identification of the isolate. The isolate was identified to be closely related to aBrucella sp. originating from a United States bottlenose dolphin (Tursiops truncatus ) and common seals (Phoca vitulina ).