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Query: UMLS:C0014118 (endocarditis)
 15,629 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Netilmicin was compared with gentamicin and streptomycin for in-vitro activity against 30 strains of penicillin-tolerant streptococci including 16 strains of enterococci. Both netilmicin and gentamicin tested alone at 4 mg/l caused 99.9% kill of more than half of the 13 strains of viridans streptococci tested, whereas streptomycin, 4 mg/l, had no bactericidal effect against these strains. Netilmicin, gentamicin and streptomycin tested alone at 8.0 mg/l against 10 strains of Streptococcus faecalis resulted in 99.9% kill of six, one and zero strains respectively. Combinations of penicillin with 2 mg/l of either netilmicin or gentamicin resulted in bactericidal synergy against 12 of 13 strains of viridans streptococci and all 10 strains of S. faecalis after 18 to 24 h incubation. Parallel experiments showed that higher concentration of penicillin were required to obtain 99.9% kill of 10 streptococcal strains when 4 mg/l streptomycin was compared with 2 mg/l of the other aminoglycosides. Killing curves showed similar bactericidal synergy for netilmicin-penicillin and gentamicin-penicillin combinations against most streptococci tested after 24 h incubation but there was sometimes a greater bactericidal effect noted with netilmicin after only 6 h incubation of the broth or after 48 h incubation. The results of this in-vitro study suggest that netilmicin is at least as effective as gentamicin as a bactericidal synergic agent with penicillin against penicillin-tolerant viridans streptococci and S. faecalis strains isolated from patients with endocarditis. Neither gentamicin or netilmicin were effective as bactericidal synergic agents with penicillin against 4 of 6 strains of S. faecium tested.
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PMID:Bactericidal activity of netilmicin compared with gentamicin and streptomycin, alone and in combination with penicillin, against penicillin tolerant viridans streptococci and enterococci. 309 5

The 50% inhibitory concentrations (IC50) of gentamicin and netilmicin were determined for 55 clinical isolates of Streptococcus faecalis, approximately half of which were recovered by culture of blood samples from patients with endocarditis. The IC50 for gentamicin was less than 5 micrograms/ml for 22 strains and less than 40 micrograms/ml for all strains, and for netilmicin the IC50 was less than 5 micrograms/ml for 51 strains and less than 40 micrograms/ml for all strains. Eight out of the 55 strains were found to have IC50 values greater than 10(4) micrograms/ml for streptomycin (3). The bacterial effect of combinations of benzylpenicillin and gentamicin or netilmicin was studied in 19 strains of S. faecalis which represented different levels of resistance to streptomycin. Netilmicin was as effective as gentamicin in combination with benzylpenicillin against all strains.
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PMID:Combined effect of benzylpenicillin and gentamicin/netilmicin on Streptococcus faecalis. 678 58

Using a rabbit model of aortic valve endocarditis, we studied the efficacy of vancomycin alone or in combination with netilmicin and/or rifampin against a methicillin- and gentamicin-resistant strain of Staphylococcus aureus (MGRSA). Antibiotics were given for 6 to 12 days, as follows: vancomycin (15 mg/kg of body weight every 12 h [BID] intravenously), vancomycin plus netilmicin (2.5 mg/kg BID intramuscularly), vancomycin plus rifampin (10 mg/kg BID intramuscularly), and vancomycin plus netilmicin plus rifampin at the same routes, dosages, and schedules mentioned above. Netilmicin was given to two additional groups at a higher dosage (6 mg/kg every 24 h intramuscularly) alone or in combination with vancomycin (15 mg/kg BID intravenously) for 12 days. All regimens resulted in undetectable bacterial counts in a significant proportion of vegetations (except netilmicin alone) or reduced the bacterial counts in the vegetations compared with the counts in the untreated controls (P<0.01 to P<0.001). No resistance to rifampin or netilmicin developed during therapy. It is concluded that in the treatment of experimental aortic valve endocarditis caused by MGRSA (i) vancomycin as monotherapy is as efficacious as the triple combination, (ii) the addition of netilmicin (once daily or BID) to vancomycin does not improve the efficacy of the latter antibiotic, even in the presence of rifampin, and (iii) a 12-day course in more effective than a 6-day one, but not at a statistically significant level.
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PMID:Vancomycin or vancomycin plus netilmicin for methicillin- and gentamicin-resistant Staphylococcus aureus aortic valve experimental endocarditis. 861 84

Several in vitro and in vivo studies as well as clinical trials have demonstrated that once-daily aminoglycoside regimens are as effective as or more effective than multiple daily dosings. However, the most favorable aminoglycoside dosing regimen for treating enterococcal endocarditis remains controversial. The same total dose of netilmicin was administered as once-daily (24-micrograms/ml peaks) and thrice-daily (8 micrograms/ml) regimens in a pharmacodynamic in vitro model simulating exposure of Enterococcus faecalis to human serum kinetics. Netilmicin was administered in combination with continuous infusions of amoxicillin, vancomycin, or penicillin against a bacterial biofilm adhering to glass beads. No significant differences in bacterial killing were found after 24 or 48 h between the once- and thrice-daily regimens. Additional experiments considering animal kinetics (half-life of netilmicin, 20 min) instead of human kinetics (half-life, 2.5 h) in the pharmacodynamic model also revealed similar results. The addition of netilmicin synergistically increased the activity of vancomycin (P < 0.05). In contrast, amoxicillin alone was as effective as the combination with netilmicin. Thus, it could not be established in this model that once-daily dosing of aminoglycosides is contraindicated for treating infections caused by E. faecalis.
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PMID:Once-versus thrice-daily netilmicin combined with amoxicillin, penicillin, or vancomycin against Enterococcus faecalis in a pharmacodynamic in vitro model. 889 Nov 25