Time-kill profiles of Enterococcus to antibiotics used for intravitreal therapy

• Published in: Ophthalmic surgery and lasers Vol. 29; no. 4; pp. 295 - 299
• Main Authors: KOWALSKI, R. P, KARENCHAK, L. M, WARREN, B. B, ELLER, A. W
• Format: Journal Article
• Language: English
• Published: Thorofare, NJ Slack 01.04.1998; SLACK INCORPORATED
• Subjects: Anti-Bacterial Agents; Antibacterial agents; Antibiotics. Antiinfectious agents. Antiparasitic agents; Biological and medical sciences; Colony Count, Microbial; Drug Therapy, Combination - pharmacology; Endophthalmitis - drug therapy; Endophthalmitis - microbiology; Enterococcus faecalis - drug effects; Enterococcus faecalis - growth & development; Enterococcus faecalis - isolation & purification; Enterococcus faecium - drug effects; Enterococcus faecium - growth & development; Enterococcus faecium - isolation & purification; Humans; Medical sciences; Microbial Sensitivity Tests; Pharmacology. Drug treatments; Vitreous Body - drug effects; Enterococcus faecalis; Human; Intravitreous administration; Bactericidal test; Uvea disease; Infection; Streptococcaceae; Eye disease; Antibiotic; Chemotherapy; Treatment; Bacteriosis; Bacteria; Micrococcales; Antibacterial agent; Endophtalmitis
• ISSN: 1082-3069; 2325-8160; 2325-8179

To determine and then compare the time-kill profiles of Enterococcus to antibiotics used for intravitreal therapy. The time-kill profiles of four endophthalmitis isolates of Enterococcus faecalis, one vancomycin-resistant E. faecalis isolate, and three vancomycin-resistant isolates of E. faecium were determined against vancomycin, amikacin, cefazolin, gentamicin, ampicillin, ciprofloxacin, ceftazidime, clindamycin, and the combinations of vancomycin and amikacin, vancomycin and ceftazidime, vancomycin and gentamicin, vancomycin and ampicillin, cefazolin and gentamicin, and ampicillin and gentamicin. No single antibiotic or combination was bactericidal (defined as 99.9% kill) to all isolates of Enterococcus. Gentamicin was bactericidal to all E. faecalis isolates. None of the tested antibiotics were bactericidal to vancomycin-resistant E. faecium. The time-kill profiles demonstrated that vancomycin and ceftazidime did not produce a 99.9% kill for E. faecalis in this small study. Gentamicin combined with either cefazolin or ampicillin had somewhat better bactericidal activity and should be considered as an alternative therapy. Novel therapy may be necessary to treat endophthalmitis because of vancomycin-resistant Enterococcus, depending on the susceptibility patterns of the individual isolate and the response to initial therapy.