title: A mycobacterial coinfection in a dog suspected on blood smear.
abstract: A 4-year-old neutered female crossbred Shepherd was referred for a history of 10 days of anorexia, polyuria, polydipsia, polyadenomegaly, and diarrhea. On physical examination, the dog appeared quiet, responsive, and apyretic, with generalized and severe lymphadenomegaly. Hematologic abnormalities included neutrophilic leukocytosis with left shift, and lymphopenia. Blood smears revealed intracytoplasmic bacilli negatively stained with May-Grünwald-Giemsa in neutrophils and monocytes. Lymph node smears revealed pyogranulomatous adenitis with calcified deposits and many negative-staining rod structures, both within the cytoplasm of neutrophils and macrophages, and free in the background. An acid-fast stain (Ziehl-Neelsen) confirmed the diagnosis of mycobacterial infection. The dog was euthanized for public health and ethical reasons, and the postmortem examination revealed severe and generalized granulomatous and necrotizing lymphadenitis, panniculitis, and hepatitis, and infiltration of epithelioid macrophages in the lungs, colon, and spleen. Numerous acid-fast bacilli, consistent with mycobacterial infection, were observed both in the cytoplasm of epithelioid macrophages and giant cells, and free in the background. Mycobacterium bovis was first confirmed by conventional PCR of organ extracts. Mycobacterium avium was detected in a culture of the same organs. Further PCR amplifications and sequencing revealed a coinfection with 2 different species of mycobacterium, one belonging to the Mycobacterium avium complex and the other to the Mycobacterium tuberculosis complex.
authors: Department of Pathology, Université de Toulouse, INP, ENVT, Toulouse, France.
authors: Claire-Lise
authors: CL
authors: Etienne
authors: Fanny
authors: F
authors: Granat
authors: Catherine
authors: C
authors: Trumel
authors: Isabelle
authors: I
authors: Raymond-Letron
authors: Marie-Noëlle
authors: MN
authors: Lucas
authors: Corine
authors: C
authors: Boucraut-Baralon
authors: Jean-Luc
authors: JL
authors: Pingret
authors: Laurent
authors: L
authors: Magne
authors: Maxence
authors: M
authors: Delverdier
mesh_terms: D000818:Animals; D016470:Bacteremia / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D044963:Biopsy, Fine-Needle / Q000662:veterinary; D060085:Coinfection / Q000662:veterinary; D004283:Dog Diseases / Q000097:blood / Q000175:diagnosis* / Q000382:microbiology; D004285:Dogs; D005260:Female; D008264:Macrophages / Q000382:microbiology; D009000:Monocytes / Q000382:microbiology; D009162:Mycobacterium avium / Q000235:genetics / Q000302:isolation & purification*; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000302:isolation & purification*; D009504:Neutrophils / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000662:veterinary; D017422:Sequence Analysis, DNA / Q000662:veterinary; D014376:Tuberculosis / Q000097:blood / Q000175:diagnosis / Q000662:veterinary*
keywords: Blood smear; Mycobacterium avium complex (MAC); Mycobacterium tuberculosis complex (MTC); PCR; coinfection