Streptomyces cyaneus dermatitis in a dog.
BACKGROUND
A nearly 4-year-old neutered male Australian Terrier was referred for a nodular pyogranulomatous mass of the right axilla. It had been poorly responsive to antibiotic therapy.


METHODS
Based on filamentous Gram-positive organisms identified in earlier biopsy material, infection by an Actinomyces sp. was suspected and the dog showed clinical improvement on a trial of potentiated sulfonamides. Recurrence 5 months later prompted euthanasia, with Streptomyces cyaneus being cultured and confirmed by genetic sequencing of part of the 16 s ribosomal RNA gene.


CONCLUSIONS
Invasive Streptomyces spp. infections are uncommon in humans and animals, and isolations are sometimes considered to be contaminants, but the demonstration of the organism within the lesion in this instance indicates that the isolation of a Streptomyces sp. from veterinary cases should not always be considered as contamination, because this genus is clearly pathogenic.
School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, 6150, Australia. P.Nicholls@murdoch.edu.au.
P K
PK
Nicholls
G
G
Allen
P J
PJ
Irwin
D000818:Animals; D001365:Axilla / Q000382:microbiology* / Q000473:pathology; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D003872:Dermatitis / Q000188:drug therapy / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D004283:Dog Diseases / Q000188:drug therapy / Q000382:microbiology* / Q000473:pathology; D004285:Dogs; D017809:Fatal Outcome; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D006651:Histocytochemistry / Q000662:veterinary; D008297:Male; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012336:RNA, Ribosomal, 16S / Q000737:chemistry / Q000235:genetics; D013302:Streptomyces / Q000235:genetics / Q000254:growth & development*; D013449:Sulfonamides / Q000008:administration & dosage / Q000627:therapeutic use*
D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D013449:Sulfonamides
Streptomyces cyaneus; dogs; pyogranulomatous dermatitis