title: Causative organisms of post-traumatic endophthalmitis: a 20-year retrospective study.
abstract: BACKGROUND
  A wide range of organisms that enter the eye following ocular trauma can cause endophthalmitis. This study was to investigate the spectrum of pathogens and antibiotic susceptibility of bacterial isolates from a large cohort of post-traumatic endophthalmitis cases.
  
  
  METHODS
  A retrospective study of 912 post-traumatic endophthalmitis patients treated at a tertiary eye-care center in China was performed. The associations between risk factors and the most common isolated organisms were investigated by Chi square Test. The percent susceptibilities for the first 10 years (1990-1999) and the second 10 years (2000-2009) were compared by Chi square test. p < 0.05 was considered statistically significant.
  
  
  RESULTS
  Three-hundred-forty-seven (38.1%) cases of endophthalmitis were culture-positive, and 11 (3.2%) showed mixed infections (Gram-negative bacilli and fungi), yielding a total of 358 microbial pathogens. Culture proven organisms included 150 (41.9%) Gram-positive cocci, 104 (29.1%) Gram-negative bacilli, 44 (12.3%) Gram-positive bacilli, and 60 (16.8%) fungi. The coagulase-negative staphylococcal (CNS) species S. epidermidis (21.8%) and S. saprophyticus (12.0%) were the predominant pathogens, followed by Bacillus subtilis (8.7%), Pseudomonas aeruginosa (7.8%), and Escherichia coli (6.4%). Delayed repair over 24 h (p < 0.001) and metallic injury (p < 0.01) were significantly associated with positive culture of CNS. The most frequent fungal species were Aspergillus (26/60), followed by yeast-like fungi (18/60). P. aeruginosa was relatively sensitive to ciprofloxacin (83.3%), cefoperazone (75%), tobramycin (75%), cefuroxime (75%), and ceftazidime (75%) during the second decade. Multi-drug resistance was observed in the predominant Gram-negative bacteria.
  
  
  CONCLUSIONS
  We identified a broad spectrum of microbes causing post-traumatic endophthalmitis, with Gram-positive cocci the most frequently identified causative organism, followed by Bacillus species, fungi, and mixed infections. CNS infection was statistically associated with delayed repair and metallic injury. Variation in antibiotic susceptibility was observed among isolated bacteria and between different periods. Ciprofloxacin and ceftazidime in the first and second decades of the study, respectively, showed the highest activity against bacterial post-traumatic endophthalmitis. For infections caused by P. aeruginosa, a combination therapy of ciprofloxacin, tobramycin, and one of the cephalosporins might provide optimal coverage according to data from the second decade.
authors.forename: Chongde
authors.initials: C
authors.lastname: Long
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 South Xianlie Road, Guangzhou, Guangdong 510060, China. bingqianliu@gmail.com.
authors.forename: Bingqian
authors.initials: B
authors.lastname: Liu
authors.forename: Chaochao
authors.initials: C
authors.lastname: Xu
authors.forename: Yuan
authors.initials: Y
authors.lastname: Jing
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Yuan
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Lin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D002681:China; D009877:Endophthalmitis / Q000382:microbiology*; D015818:Eye Infections, Bacterial / Q000382:microbiology*; D015821:Eye Infections, Fungal / Q000382:microbiology*; D015807:Eye Injuries, Penetrating / Q000150:complications*; D005260:Female; D005658:Fungi / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents