title: Zoonotic necrotizing myositis caused by Streptococcus equi subsp. zooepidemicus in a farmer.
abstract: Streptococcus equi subsp. zooepidemicus is a beta-hemolytic group C streptococcus mainly causing infections in domesticated animals. Here we describe the first case of zoonotic necrotizing myositis caused by this bacterium.
  
  
  
  The patient was a 73-year-old, previously healthy farmer with two asymptomatic Shetland ponies in his stable. After close contact with the ponies while feeding them, he rapidly developed erythema of his left thigh and sepsis with multiple organ failure. The clinical course was severe and complicated, requiring repetitive surgical excision of necrotic muscle, treatment with vasopressors, mechanical ventilation and continuous venovenous hemofiltration, along with adjunctive hyperbaric oxygen therapy. The patient was discharged from hospital at day 30, without obvious sequelae. The streptococcal isolate was identified as Streptococcus equi by MALDI-ToF MS, and was later assigned subspecies identification as S. equi subsp. zooepidemicus. Multilocus sequence typing identified the strain as a novel sequence type (ST 364), closely related to types previously identified in horses and cattle. A focused proteomic analysis revealed that the ST 364 expressed putative virulence factors similar to that of Streptococcus pyogenes, including homologues of the M protein, streptodornases, interleukin 8-protease and proteins involved in the biosynthesis of streptolysin S.
  
  
  
  This case illustrates the zoonotic potential of S. equi subsp. zooepidemicus and the importance of early clinical recognition, rapid and radical surgical therapy, appropriate antibiotics and adequate supportive measures when necrotizing soft tissue infection is suspected. The expression of Streptococcus pyogenes-like putative virulence determinants in ST 364 might partially explain the fulminant clinical picture.
authors.affiliation: Department of Medicine, Haraldsplass Deaconess Hospital, Bergen, Norway. brki@haraldsplass.no.
authors.forename: Bård Reiakvam
authors.initials: BR
authors.lastname: Kittang
authors.affiliation: The Gade Research Group for Infection and Immunity, Department of Clinical Science, University of Bergen, Bergen, Norway.
authors.forename: Veronika Kuchařová
authors.initials: VK
authors.lastname: Pettersen
authors.affiliation: The Gade Research Group for Infection and Immunity, Department of Clinical Science, University of Bergen, Bergen, Norway.|Department of Medicine, Haukeland University Hospital, Bergen, Norway.
authors.forename: Oddvar
authors.initials: O
authors.lastname: Oppegaard
authors.affiliation: The Gade Research Group for Infection and Immunity, Department of Clinical Science, University of Bergen, Bergen, Norway.|Department of Microbiology, Haukeland University Hospital, Bergen, Norway.
authors.forename: Dag Harald
authors.initials: DH
authors.lastname: Skutlaberg
authors.affiliation: Department of Orthopaedic Surgery, Haukeland University Hospital, Bergen, Norway.
authors.forename: Håvard
authors.initials: H
authors.lastname: Dale
authors.affiliation: The Gade Research Group for Infection and Immunity, Department of Clinical Science, University of Bergen, Bergen, Norway.|Department of Microbiology, Haukeland University Hospital, Bergen, Norway.
authors.forename: Harald G
authors.initials: HG
authors.lastname: Wiker
authors.affiliation: The Gade Research Group for Infection and Immunity, Department of Clinical Science, University of Bergen, Bergen, Norway.|Department of Medicine, Haukeland University Hospital, Bergen, Norway.
authors.forename: Steinar
authors.initials: S
authors.lastname: Skrede
mesh_terms: D000368:Aged; D000822:Animal Husbandry; D000818:Animals; D003882:Dermatomyositis / Q000276:immunology / Q000382:microbiology* / Q000628:therapy; D000067565:Farmers; D019115:Fasciitis, Necrotizing / Q000382:microbiology* / Q000628:therapy; D006440:Hemofiltration; D006734:Horse Diseases / Q000276:immunology / Q000382:microbiology*; D006736:Horses; D006801:Humans; D006931:Hyperbaric Oxygenation; D008297:Male; D058885:Multilocus Sequence Typing; D009102:Multiple Organ Failure / Q000382:microbiology* / Q000628:therapy; D013290:Streptococcal Infections / Q000382:microbiology* / Q000628:therapy / Q000662:veterinary; D018502:Streptococcus equi / Q000276:immunology / Q000472:pathogenicity*; D016896:Treatment Outcome; D014662:Vasoconstrictor Agents / Q000627:therapeutic use; D015047:Zoonoses
chemical_list: D014662:Vasoconstrictor Agents
keywords: Case report; Necrotizing myositis; Streptococcus equi subsp. zooepidemicus; Zoonosis