title: Emerging role of Raoultella ornithinolytica in human infections: a series of cases and review of the literature.
abstract: BACKGROUND
  Raoultella ornithinolytica is known to inhabit aquatic environments. The clinical features and outcomes of human infections caused by R. ornithinolytica have been reported for only a limited number of cases.
  
  
  METHODS
  A retrospective study of cases of infection caused by R. ornithinolytica managed at four university hospital centres during the period before and after the introduction of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was performed. The aim was to describe the clinical and microbiological characteristics, treatments, and outcomes.
  
  
  RESULTS
  Among 187 R. ornithinolytica isolates identified for which clinical information was available, 71 were considered colonizers and 116 were pathogenic. A total of 112 cases of R. ornithinolytica infection were identified. Urinary tract infections, gastrointestinal infections, wound and skin infections, and bacteraemia were observed in 36%, 14%, 13%, and 5% of cases, respectively. Associated infections that have been poorly reported, such as respiratory infections, i.e. pneumonia and pleural effusion, were observed in 24% of cases. Additional diseases reported here for the first time included osteomyelitis, meningitis, cerebral abscess, mediastinitis, pericarditis, conjunctivitis, and otitis. The proportion of R. ornithinolytica isolates resistant to antibiotics was found to be relatively high: 4% of isolates were resistant to ceftriaxone, 6% to quinolones, and 13% to co-trimoxazole. The mortality rate related to infection was 5%.
  
  
  CONCLUSIONS
  R. ornithinolytica is an underreported, emerging hospital-acquired infection and is particularly associated with invasive procedures. R. ornithinolytica should never be considered simply a saprophytic bacterium that occasionally contaminates bronchial lavage or other deep respiratory samples or surgical sites. Physicians should be aware of the high rates of antimicrobial resistance of R. ornithinolytica isolates so that immediate broad-spectrum antibiotic treatment can be established before accurate microbiological results are obtained.
authors.affiliation: Centre de Référence des Infections Ostéo-Articulaires (CRIOAC) Interrégional Sud Méditerranée, Service des Maladies Infectieuses, Hôpital de la Conception, 147 boulevard Baille, 13005 Marseille, France; Aix-Marseille Université, Faculté de Médecine, Marseille, France. Electronic address: sengpiseth@yahoo.fr.
authors.forename: Piseth
authors.initials: P
authors.lastname: Seng
authors.affiliation: Centre de Référence des Infections Ostéo-Articulaires (CRIOAC) Interrégional Sud Méditerranée, Service des Maladies Infectieuses, Hôpital de la Conception, 147 boulevard Baille, 13005 Marseille, France.
authors.forename: Boushab Mohamed
authors.initials: BM
authors.lastname: Boushab
authors.affiliation: Service d'Informatique Médicale, Hôpital de la Conception, Marseille, France.
authors.forename: Fanny
authors.initials: F
authors.lastname: Romain
authors.affiliation: Aix-Marseille Université, Faculté de Médecine, Marseille, France.
authors.forename: Frédérique
authors.initials: F
authors.lastname: Gouriet
authors.affiliation: Département d'Anesthésie-réanimation et Soins Intensif, Hôpital de la Timone, Marseille, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Bruder
authors.affiliation: Service d'Anesthésie et de Réanimation, Hôpital Nord, Marseille, France.
authors.forename: Claude
authors.initials: C
authors.lastname: Martin
authors.affiliation: Département de Cardiologie, Hôpital Nord, Marseille, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Paganelli
authors.affiliation: Département de Médecine Interne, Hôpital de la Conception, Marseille, France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Bernit
authors.affiliation: Département de Chirurgie Digestive et Transplantation Hépatique, Hôpital de la Conception, Marseille, France.
authors.forename: Yves Patrice
authors.initials: YP
authors.lastname: Le Treut
authors.affiliation: Département de Chirurgie Thoracique, Transplantation Pulmonaire et Maladies Respiratoires, Hôpital Nord, Marseille, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Thomas
authors.affiliation: Réanimation Médicale Détresses Respiratoires - Infections Sévères, Hôpital Nord, Marseille, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Papazian
authors.affiliation: Aix-Marseille Université, Faculté de Médecine, Marseille, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
authors.affiliation: Centre de Référence des Infections Ostéo-Articulaires (CRIOAC) Interrégional Sud Méditerranée, Service des Maladies Infectieuses, Hôpital de la Conception, 147 boulevard Baille, 13005 Marseille, France; Aix-Marseille Université, Faculté de Médecine, Marseille, France.
authors.forename: Andreas
authors.initials: A
authors.lastname: Stein
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016470:Bacteremia / Q000382:microbiology; D003428:Cross Infection / Q000382:microbiology; D024881:Drug Resistance, Bacterial; D004755:Enterobacteriaceae / Q000187:drug effects / Q000302:isolation & purification*; D004756:Enterobacteriaceae Infections / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D012189:Retrospective Studies
chemical_list: D000900:Anti-Bacterial Agents
keywords: Bacteria; Human; Infection; Klebsiella ornithinolytica; Raoultella ornithinolytica