title: Clinical characteristics and risk factors of pyogenic spondylitis caused by gram-negative bacteria.
abstract: BACKGROUND
  There are limited data describing the clinical characteristics of pyogenic spondylitis caused by Gram-negative bacteria (GNB). The aim of this study was to investigate the predisposing factors and clinical characteristics of pyogenic spondylitis caused by GNB compared to Gram-positive cocci (GPC).
  
  
  METHODS
  We performed a retrospective review of medical records from patients with culture-confirmed pyogenic spondylitis at four tertiary teaching hospitals over an 8-year period.
  
  
  RESULTS
  A total of 344 patients with culture-confirmed pyogenic spondylitis were evaluated. There were 62 patients (18.0%) with pyogenic spondylitis caused by GNB and the most common organism was Escherichia coli (n = 35, 10.2%), followed by Pseudomonas aeruginosa (n = 10, 2.9%). Pyogenic spondylitis caused by GNB was more frequently associated with the female gender (64.5 vs. 35.5%, P <0.01), preexisting or synchronous genitourinary tract infection (32.3 vs. 2.1%, P< 0.01), and intra-abdominal infection (12.9 vs. 0.4%, P< 0.01) compared to patients with GPC. Although pyogenic spondylitis caused by GNB presented with severe sepsis more frequently (24.2 vs. 11.3%, P = 0.01), the mortality rate (6.0 vs. 5.2%) and the proportion of patients with residual disability (6.0 vs. 9.0%), defined as grade 3 or 4 (P = 0.78) 3 months after completion of treatment, were not significantly different compared to GPC patients.
  
  
  CONCLUSIONS
  GNB should be considered as the etiologic organism when infectious spondylitis develops in a patient with preexisting or synchronous genitourinary tract and intra-abdominal infection. In addition, the mortality rate and clinical outcomes are not significantly different between pyogenic spondylitis caused by GNB and GPC.
authors.affiliation: Department of Infectious Diseases, Chonnam National University Medical School, Gwangju, South Korea.
authors.forename: Seung-Ji
authors.initials: SJ
authors.lastname: Kang
authors.affiliation: Department of Infectious Diseases, Chonnam National University Medical School, Gwangju, South Korea.
authors.forename: Hee-Chang
authors.initials: HC
authors.lastname: Jang
authors.affiliation: Department of Infectious Diseases, Chonnam National University Medical School, Gwangju, South Korea.
authors.forename: Sook-In
authors.initials: SI
authors.lastname: Jung
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Pyoeng Gyun
authors.initials: PG
authors.lastname: Choe
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Wan Beom
authors.initials: WB
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Chung-Jong
authors.initials: CJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Kyoung-Ho
authors.initials: KH
authors.lastname: Song
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Eu Suk
authors.initials: ES
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Hong Bin
authors.initials: HB
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Myoung-Don
authors.initials: MD
authors.lastname: Oh
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Nam Joong
authors.initials: NJ
authors.lastname: Kim
authors.affiliation: Department of Infectious Diseases, Chonnam National University Medical School, Gwangju, South Korea.
authors.forename: Kyung-Hwa
authors.initials: KH
authors.lastname: Park
mesh_terms: D000368:Aged; D003428:Cross Infection / Q000209:etiology / Q000382:microbiology / Q000473:pathology; D005260:Female; D006090:Gram-Negative Bacteria / Q000472:pathogenicity*; D016905:Gram-Negative Bacterial Infections / Q000209:etiology* / Q000382:microbiology / Q000473:pathology*; D006095:Gram-Positive Cocci / Q000472:pathogenicity; D006801:Humans; D059413:Intraabdominal Infections / Q000209:etiology / Q000382:microbiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D018805:Sepsis / Q000209:etiology / Q000382:microbiology / Q000473:pathology; D013166:Spondylitis / Q000209:etiology* / Q000382:microbiology / Q000473:pathology*; D062606:Tertiary Care Centers; D016896:Treatment Outcome