title: Septic nonunions of lower limb long bones: don't neglect Propionibacterium acnes!
abstract: We report 3 clinical cases of septic nonunions of lower limb long bones in which the pathogenicity of Propionibacterium acnes was retained after several weeks of poor outcome. The patients had fractures that were treated by internal fixation, without initially suspected infection. The diagnosis of delayed union coincided with the onset of treatment. Support was performed in 2 steps, allowing for the collection of several deep samples that were referred for microbiological analysis. Molecular techniques for microbiological investigation were performed on perioperative samples and were not contributive. The detection of P acnes, which was identified after several days of incubation, prompted us to consider the role of this bacterium. The presence of P acnes is regularly interpreted as contamination of samples during collection or handling in the laboratory. A multidisciplinary decision to make the diagnosis of surgical site infection with P acnes and specific antibiotic treatment for several months led to consolidation in all the patients. The ability of bacteria of the genus Propionibacterium to cause insidious surgical site infections should not be underestimated, and more extensive sample incubation is essential to diagnose such infections.
authors.affiliation: 1Hôpital d'Instruction des Armées Sainte Anne, Toulon, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Gaillard
authors.forename: Marc
authors.initials: M
authors.lastname: Dupond
authors.forename: Patrick
authors.initials: P
authors.lastname: Brisou
authors.forename: Tiphaine
authors.initials: T
authors.lastname: Gaillard
mesh_terms: D000328:Adult; D000658:Amoxicillin / Q000008:administration & dosage*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D005593:Fracture Fixation, Internal / Q000009:adverse effects* / Q000379:methods; D017102:Fracture Healing / Q000187:drug effects; D005599:Fractures, Ununited / Q000209:etiology*; D006801:Humans; D035002:Lower Extremity / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D008875:Middle Aged; D011425:Propionibacterium acnes / Q000302:isolation & purification*; D012293:Rifampin / Q000008:administration & dosage*; D013530:Surgical Wound Infection / Q000188:drug therapy / Q000382:microbiology / Q000503:physiopathology; D013978:Tibial Fractures / Q000601:surgery*; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D000658:Amoxicillin; D012293:Rifampin
keywords: Propionibacterium; Propionibacterium acnes; SSI; bone infection; nonunion; surgical site infection