Endocarditis due to group D streptococci

Moellering, Robert C.; Watson, Barbara K.; Kunz, Lawrence J.

doi:10.1016/0002-9343(74)90448-3

Cited by 137 publications

(20 citation statements)

References 21 publications

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“…bactericidal activities of ,-lactam antibiotics (21,29). However, many investigators have used maximum concentrations of penicillin that were not much higher than the MIC for the particular strain under study; e.g., 4x the MIC was not bactericidal (23).…”

Section: Resultsmentioning

confidence: 99%

Correlation of penicillin-induced lysis of Enterococcus faecium with saturation of essential penicillin-binding proteins and release of lipoteichoic acid

Al-Obeid

Gutmann

Williamson

1990

Antimicrob Agents Chemother

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Clinical isolates of Enterococcusfaecium that had a range of susceptibilities to penicillin were found to differ significantly in their responses to the antibiotic. In the penicillin-susceptible group (MIC, <4 ,ug/ml), the cessation of growth (bacteriostasis) at 1Ox the MIC of penicillin appeared to correlate with the inhibition of penicillin-binding protein (PBP) 5*, whereas the onset of lysis (bactericidal effect) at higher antibiotic concentrations (10OX the MIC) was concomitant with the inhibition of the lower-affinity PBP 5. In contrast, in the resistant (MIC, -8 ,ug/ml) group (in which most of the strains did not contain PBP 5*), the degree of saturation of PBP 5 seemed to determine the physiological response to the antibiotic: low levels of saturation caused growth inhibition, whereas almost complete saturation correlated with lysis. The penicillin-induced cell lysis of both penicillin-susceptible and -resistant strains was attributed, at least in part, to the extensive loss of acylated lipoteichoic acid into the growth medium.

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Section: Resultsmentioning

confidence: 99%

Correlation of penicillin-induced lysis of Enterococcus faecium with saturation of essential penicillin-binding proteins and release of lipoteichoic acid

Al-Obeid

Gutmann

Williamson

1990

Antimicrob Agents Chemother

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“…Entero cocci had been recognized previously as causative agents of subacute bacterial en docarditis [19]. Originally, cases of entero coccal endocarditis had been treated with the classical combination of penicillin G plus streptomycin [13,14].…”

Section: Introductionmentioning

confidence: 99%

<i>Streptococcus faecalis</i>: in vitro Susceptibility to Antimicrobial Drugs, Single and Combined, with and without Defibrinated Human Blood

Traub

Spohr

Bauer³

1986

Chemotherapy

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Ampicillin, fusidic acid, gentamicin, imipenem, mezlocillin, ofloxacin, penicillin G, piperacillin, and vancomycin were examined for inhibitory and bactericidal activity in various broth media against 7 clinical isolates of Streptococcus faecalis. On a weight-for-weight basis, ampicillin, imipenem, mezlocillin, and ofloxacin proved to be more efficacious. All enterococcal isolates were resistant against gentamicin; fusidic acid and vancomycin lacked bactericidal activity. The combinations of either ampicillin, imipenem, mezlocillin, ofloxacin, piperacillin, or vancomycin with a subinhibitory concentration (4 μg/ml) of gentamicin, with or without added 65% (v/v) fresh defibrinated human blood, respectively, yielded additive effects against all enterococcal isolates. The addition of fresh human blood failed to enhance the antienterococcal activity of 4 μg/ml of gentamicin; in contrast, addition of 65% (v/v) fresh or heat-inactivated (56°C, 30 min) normal rabbit, bovine, and human sera augmented the activity of gentamicin, an effect that was ablated through the addition of either 0.005 M DTT or 0.01 M MgCl₂ + 0.01 M EGTA + 0.01 M CaCl₂, supplements known to antagonize human serum β-lysin, but not lysozyme activity.

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“…The minimal inhibitory concentrations (MICs) of beta-lactam antibiotics for these organisms are substantially higher than for other streptococci (18,29). In addition, even at antibiotic concentrations in excess of the MIC, enterococci demonstrate tolerance to the usual killing effect of all cell wall-active agents (16).…”

mentioning

confidence: 99%

Resistance to antibiotic synergism in Streptococcus faecalis: further studies with amikacin and with a new amikacin derivative, 4'-deoxy, 6'-N-methylamikacin

Calderwood¹,

Wennersten²,

Moellering³

1981

Antimicrob Agents Chemother

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Streptococcus faecalis strains may resist penicillin-aminoglycoside synergy by the production of plasmid-mediated aminoglycoside-modifying enzymes. One of these enzymes, aminoglycoside 3'-phosphotransferase, has been shown to have a broad range of substrate specificity, including amikacin. We have studied a derivative of amikacin, 4'-deoxy, 6'-N-methylamikacin (BB-K311), against 11 clinical blood isolates of S. faecalis. Minimal inhibitory concentrations of BB-K311 were quite similar to those of amikacin, ranging from 125 to 1,000 micrograms/ml. In assays for antibiotic synergy, penicillin and amikacin produced enhanced killing compared with the penicillin alone only against those three strains which lacked the phosphotransferase enzyme. The other eight enzyme-positive strains actually demonstrated significant antagonism between penicillin against all 11 strains, regardless of enzyme production. Analysis of substrate profiles with crude preparations of the aminoglycoside 3'-phosphotransferase enzyme confirmed that BB-K311 was a very poor substrate for modification, as expected from the synergy studies. Use of other aminoglycoside analogs confirmed the 3'-OH site of modification. These findings suggest that removing the 4'-OH group in amikacin effectively blocks 3'-phosphorylation by S. faecalis enzyme.

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Endocarditis due to group D streptococci

Cited by 137 publications

References 21 publications

Correlation of penicillin-induced lysis of Enterococcus faecium with saturation of essential penicillin-binding proteins and release of lipoteichoic acid

Correlation of penicillin-induced lysis of Enterococcus faecium with saturation of essential penicillin-binding proteins and release of lipoteichoic acid

<i>Streptococcus faecalis</i>: in vitro Susceptibility to Antimicrobial Drugs, Single and Combined, with and without Defibrinated Human Blood

Resistance to antibiotic synergism in Streptococcus faecalis: further studies with amikacin and with a new amikacin derivative, 4'-deoxy, 6'-N-methylamikacin

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