BACTERIAL-GROWTH IN HUMAN VITREOUS-HUMOR

The aim of this study was to investigate the capacity of human vitreou s to support bacterial growth and to show differences in the growth ki netics of gram-positive and gram-negative bacteria. Vitreous gel of 70 keratoplasty donor eyes was sampled under sterile conditions, screene d microscopically for cellular components and tested for sterility and levels of antibiotic drugs by bio-assay. The samples were inoculated with clinical isolates of Pseudomonas aeruginosa, Klebsiella pneumonia e, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus vi ridans and Streptococcus pyogenes. As control each strain was added bo th to 0.9 % sodium chloride solution and to Mueller-Hinton broth. In o rder to determine bacterial growth the number of colony forming units was determined 4, 6, 24, 48 and 72 hr after inoculation by viable coun t. Vitreous gel did not support bacterial growth; the tested strains c ould not be recovered after 48 hr. Similar results could be obtained w ith sodium chloride; whereas in Mueller Hinton broth the strains showe d normal pattern of growth. it seems that vitreous humor has inherent antibacterial capacity in vitro, although the responsible factors rema in unknown. (C) 1997 Academic Press Limited.