Abstract
RP 59500 is a new injectable streptogramin composed of two synergistic components (quinupristin and dalfopristin) which are active against erythromycin-susceptible and -resistant gram-positive pathogens. The present experiments compared the therapeutic efficacy of RP 59500 with that of vancomycin against experimental endocarditis due to either of two erythromycin-susceptible or two constitutively erythromycin-resistant isolates of methicillin-resistant Staphylococcus aureus. RP 59500 had low MICs for the four test organisms as well as for 24 additional isolates (the MIC at which 90% of the isolates were inhibited was < 1 mg/liter) which were mostly inducibly (47%) or constitutively (39%) erythromycin resistant. Aortic endocarditis in rats was produced with catheter-induced vegetations. Three-day therapy was initiated 12 h after infection, and the drugs were delivered via a computerized pump, which permitted the mimicking of the drug kinetics produced in human serum by twice-daily intravenous injections of 7 mg of RP 59500 per kg of body weight or 1 g of vancomycin. Both antibiotics reduced vegetation bacterial titers to below detection levels in ca. 70% of animals infected with the erythromycin-susceptible isolates (P < 0.05 compared with titers in controls). Vancomycin was also effective against the constitutively resistant strains, but RP 59500 failed against these isolates. Further experiments proved that RP 59500 failures were related to the very short life span of dalfopristin in serum (< or = 2 h, compared with > or = 6 h for quinupristin), since successful treatment was restored by artificially prolonging the dalfopristin levels for 6 h. Thus, RP 59500 is a promising alternative to vancomycin against methicillin-resistant S. aureus infections, provided that pharmacokinetic parameters are adjusted to afford prolonged levels of both of its constituents in serum. This observation is also relevant to humans, in whom the life span of dalfopristin in serum is also shorter than that of quinupristin.
Full Text
The Full Text of this article is available as a PDF (228.6 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Aldridge K. E., Schiro D. D., Varner L. M. In vitro antistaphylococcal activity and testing of RP 59500, a new streptogramin, by two methods. Antimicrob Agents Chemother. 1992 Apr;36(4):854–855. doi: 10.1128/aac.36.4.854. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Aumercier M., Bouhallab S., Capmau M. L., Le Goffic F. RP 59500: a proposed mechanism for its bactericidal activity. J Antimicrob Chemother. 1992 Jul;30 (Suppl A):9–14. doi: 10.1093/jac/30.suppl_a.9. [DOI] [PubMed] [Google Scholar]
- Brumfitt W., Hamilton-Miller J. M., Shah S. In-vitro activity of RP 59500, a new semisynthetic streptogramin antibiotic, against gram-positive bacteria. J Antimicrob Chemother. 1992 Jul;30 (Suppl A):29–37. doi: 10.1093/jac/30.suppl_a.29. [DOI] [PubMed] [Google Scholar]
- Brumfitt W., Hamilton-Miller J. Methicillin-resistant Staphylococcus aureus. N Engl J Med. 1989 May 4;320(18):1188–1196. doi: 10.1056/NEJM198905043201806. [DOI] [PubMed] [Google Scholar]
- Chambers H. F. Studies of RP 59500 in vitro and in a rabbit model of aortic valve endocarditis caused by methicillin-resistant Staphylococcus aureus. J Antimicrob Chemother. 1992 Jul;30 (Suppl A):117–122. doi: 10.1093/jac/30.suppl_a.117. [DOI] [PubMed] [Google Scholar]
- Entenza J. M., Fluckiger U., Glauser M. P., Moreillon P. Antibiotic treatment of experimental endocarditis due to methicillin-resistant Staphylococcus epidermidis. J Infect Dis. 1994 Jul;170(1):100–109. doi: 10.1093/infdis/170.1.100. [DOI] [PubMed] [Google Scholar]
- Etienne S. D., Montay G., Le Liboux A., Frydman A., Garaud J. J. A phase I, double-blind, placebo-controlled study of the tolerance and pharmacokinetic behaviour of RP 59500. J Antimicrob Chemother. 1992 Jul;30 (Suppl A):123–131. doi: 10.1093/jac/30.suppl_a.123. [DOI] [PubMed] [Google Scholar]
- Fantin B., Leclercq R., Merlé Y., Saint-Julien L., Veyrat C., Duval J., Carbon C. Critical influence of resistance to streptogramin B-type antibiotics on activity of RP 59500 (quinupristin-dalfopristin) in experimental endocarditis due to Staphylococcus aureus. Antimicrob Agents Chemother. 1995 Feb;39(2):400–405. doi: 10.1128/aac.39.2.400. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fantin B., Leclercq R., Ottaviani M., Vallois J. M., Maziere B., Duval J., Pocidalo J. J., Carbon C. In vivo activities and penetration of the two components of the streptogramin RP 59500 in cardiac vegetations of experimental endocarditis. Antimicrob Agents Chemother. 1994 Mar;38(3):432–437. doi: 10.1128/aac.38.3.432. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fass R. J. In vitro activity of RP 59500, a semisynthetic injectable pristinamycin, against staphylococci, streptococci, and enterococci. Antimicrob Agents Chemother. 1991 Mar;35(3):553–559. doi: 10.1128/aac.35.3.553. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fluckiger U., Francioli P., Blaser J., Glauser M. P., Moreillon P. Role of amoxicillin serum levels for successful prophylaxis of experimental endocarditis due to tolerant streptococci. J Infect Dis. 1994 Jun;169(6):1397–1400. doi: 10.1093/infdis/169.6.1397. [DOI] [PubMed] [Google Scholar]
- Franciolli M., Bille J., Glauser M. P., Moreillon P. Beta-lactam resistance mechanisms of methicillin-resistant Staphylococcus aureus. J Infect Dis. 1991 Mar;163(3):514–523. doi: 10.1093/infdis/163.3.514. [DOI] [PubMed] [Google Scholar]
- Frieden T. R., Munsiff S. S., Low D. E., Willey B. M., Williams G., Faur Y., Eisner W., Warren S., Kreiswirth B. Emergence of vancomycin-resistant enterococci in New York City. Lancet. 1993 Jul 10;342(8863):76–79. doi: 10.1016/0140-6736(93)91285-t. [DOI] [PubMed] [Google Scholar]
- Hamilton-Miller J. M. In-vitro activities of 14-, 15- and 16-membered macrolides against gram-positive cocci. J Antimicrob Chemother. 1992 Feb;29(2):141–147. doi: 10.1093/jac/29.2.141. [DOI] [PubMed] [Google Scholar]
- Handwerger S., Raucher B., Altarac D., Monka J., Marchione S., Singh K. V., Murray B. E., Wolff J., Walters B. Nosocomial outbreak due to Enterococcus faecium highly resistant to vancomycin, penicillin, and gentamicin. Clin Infect Dis. 1993 Jun;16(6):750–755. doi: 10.1093/clind/16.6.750. [DOI] [PubMed] [Google Scholar]
- Héraïef E., Glauser M. P., Freedman L. R. Natural history of aortic valve endocarditis in rats. Infect Immun. 1982 Jul;37(1):127–131. doi: 10.1128/iai.37.1.127-131.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Inoue M., Okamoto R., Okubo T., Inoue K., Mitsuhashi S. Comparative in-vitro activity of RP 59500 against clinical bacterial isolates. J Antimicrob Chemother. 1992 Jul;30 (Suppl A):45–51. doi: 10.1093/jac/30.suppl_a.45. [DOI] [PubMed] [Google Scholar]
- Leclercq R., Nantas L., Soussy C. J., Duval J. Activity of RP 59500, a new parenteral semisynthetic streptogramin, against staphylococci with various mechanisms of resistance to macrolide-lincosamide-streptogramin antibiotics. J Antimicrob Chemother. 1992 Jul;30 (Suppl A):67–75. doi: 10.1093/jac/30.suppl_a.67. [DOI] [PubMed] [Google Scholar]
- Neu H. C., Chin N. X., Gu J. W. The in-vitro activity of new streptogramins, RP 59500, RP 57669 and RP 54476, alone and in combination. J Antimicrob Chemother. 1992 Jul;30 (Suppl A):83–94. doi: 10.1093/jac/30.suppl_a.83. [DOI] [PubMed] [Google Scholar]
- Noble W. C., Virani Z., Cree R. G. Co-transfer of vancomycin and other resistance genes from Enterococcus faecalis NCTC 12201 to Staphylococcus aureus. FEMS Microbiol Lett. 1992 Jun 1;72(2):195–198. doi: 10.1016/0378-1097(92)90528-v. [DOI] [PubMed] [Google Scholar]