title: Clinical manifestations and bacteriological features of culture-proven Gram-negative bacterial arthritis.
abstract: OBJECTIVE
  To investigate the clinical manifestations and bacteriological features of culture-proven, Gram-negative bacterial arthritis.
  
  
  METHODS
  This study was conducted at the Chi Mei Medical Center, a 1300-bed teaching hospital located in southern Taiwan. Patients with synovial fluid cultures positive for Gram-negative bacilli (GNB) during the period January 2009 to May 2014 were identified from the hospital's computerized microbiology database.
  
  
  RESULTS
  During the study period, a total of 48 patients with culture-confirmed, GNB septic arthritis were identified. In the majority of patients (n = 33, 68.8%), the knee was the most commonly involved joint. The most common causative pathogen was Pseudomonas spp. (n = 16, 33.3%), followed by Escherichia coli (n = 13, 28.1%). Among the 29 clinical isolates of Enterobacteriaceae, eight (27.6%) were resistant to ceftriaxone and six (20.7%) were resistant to cefpirome. Three E. coli isolates and three Klebsiella pneumoniae isolates were extended-spectrum beta-lactamase producers (n = 6, 20.7%). Among the nonfermenting GNB (NFGNB), 21.1% were resistant to ceftazidime, 21.1% were resistant to ciprofloxacin, 26.3% were resistant to piperacillin-tazobactam, and 15.8% were resistant to imipenem. The overall mortality rate was 10.4%, and the significant risk factors for death were concomitant bacteremia [odds ratio (OR): 14.6, 95% confidence interval (CI): 1.9-115.2, p = 0.011] and liver cirrhosis (OR: 20.0, 95% CI: 2.4-169.9, p = 0.006).
  
  
  CONCLUSIONS
  Approximately 25% of cases of septic arthritis were due to GNB and resistance to commonly used antimicrobial agents was common. Liver cirrhosis and concomitant bacteremia were significant risk factors for death.
authors.affiliation: Department of Trauma, Chi Mei Medical Center, Tainan, Taiwan; Department of Physical Therapy, Shu Zen Junior College of Medicine and Management, Kaohsiung, Taiwan.
authors.forename: Wei-Ting
authors.initials: WT
authors.lastname: Lin
authors.affiliation: Department of Medicine, Chi Mei Medical Center, Tainan, Taiwan; Department of Health and Nutrition, Chia Nan University of Pharmacy and Science, Tainan, Taiwan.
authors.forename: Hung-Jen
authors.initials: HJ
authors.lastname: Tang
authors.affiliation: Department of Intensive Care Medicine, Chi Mei Medical Center, Liouying, Tainan, Taiwan.
authors.forename: Chih-Cheng
authors.initials: CC
authors.lastname: Lai
authors.affiliation: Department of Intensive Care Medicine, Chi Mei Medical Center, Liouying, Tainan, Taiwan; Department of Nursing, Min-Hwei College of Health Care Management, Tainan, Taiwan. Electronic address: ccm870958@yahoo.com.tw.
authors.forename: Chien-Ming
authors.initials: CM
authors.lastname: Chao
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001170:Arthritis, Infectious / Q000453:epidemiology / Q000382:microbiology* / Q000473:pathology*; D024881:Drug Resistance, Bacterial; D005260:Female; D006090:Gram-Negative Bacteria / Q000145:classification / Q000302:isolation & purification*; D016905:Gram-Negative Bacterial Infections / Q000453:epidemiology / Q000382:microbiology* / Q000473:pathology*; D006784:Hospitals, Teaching; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis; D013582:Synovial Fluid / Q000382:microbiology; D013624:Taiwan / Q000453:epidemiology
keywords: Gram-negative bacteria; antibiotic resistance; outcome; septic arthritis