Antibiotic resistance pattern and visual outcome in experimentally-induced Staphylococcus epidermidis endophthalmitis in a rabbit model

Ophthalmology. 2001 Mar;108(3):470-8. doi: 10.1016/s0161-6420(00)00545-5.

Abstract

Objective: To study whether the clinical outcome of Staphylococcus epidermidis-induced endophthalmitis in rabbits is related to the antibiotic resistance pattern of the infecting strain.

Design: Experimental animal study.

Participants: The right eyes of 36 New Zealand white albino rabbits were inoculated with strains of S. epidermidis that displayed various patterns of antibiotic resistance.

Methods: There were 12 rabbits in each of three study groups: fully antibiotic susceptible (FS), partially antibiotic resistant (PR), and multiresistant (MR). Five days after inoculation, the eyes were enucleated and prepared for histologic studies.

Main outcome measures: Comparisons among the three groups were made based on electroretinographic (ERG) findings, histologic evaluation by a masked observer, and clinical examination.

Results: Electroretinographic findings on all rabbits were made by an unmasked observer. At 30 hours after inoculation, the ERG was diminished to 65% of normal for group FS, compared with a flat ERG waveform for groups PR (P < 0.05) and MR (P < 0.05). The ERG waveform was flat for all three groups at 72 hours after inoculation. Histologic evaluation by use of a histologic score revealed that the degree of inflammation and destruction of the retina was less for group FS (n = 10) compared with groups PR (n = 8) and MR (n = 8). Clinical examination revealed that there was a trend of less ocular inflammation for group FS compared with groups PR and MR.

Conclusions: In a rabbit model of S. epidermidis-induced endophthalmitis, antibiotic-susceptible strains caused less inflammation and destruction of the infected retina than did antibiotic-resistant strains.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology*
  • Drug Resistance, Microbial
  • Electroretinography
  • Endophthalmitis / microbiology*
  • Endophthalmitis / pathology
  • Eye Infections, Bacterial* / microbiology
  • Eye Infections, Bacterial* / pathology
  • Female
  • Microbial Sensitivity Tests
  • Models, Animal
  • Rabbits
  • Retina / physiology
  • Staphylococcal Infections* / microbiology
  • Staphylococcal Infections* / pathology
  • Staphylococcus epidermidis / drug effects
  • Staphylococcus epidermidis / pathogenicity*
  • Virulence
  • Visual Acuity*

Substances

  • Anti-Bacterial Agents