TY - JOUR
T1 - Synergism at clinically attainable concentrations of aminoglycoside and β-lactam antibiotics
AU - Hooton, T. M.
AU - Blair, A. D.
AU - Turck, M.
AU - Counts, G. W.
PY - 1984
Y1 - 1984
N2 - We evaluated the in vitro synergistic activity at clinically attainable concentrations of combinations of aminoglycoside and β-lactam antibiotics against 30 gentamicin-resistant clinical isolates of gram-negative bacilli. All 56 pairs of 4 aminoglycosides and 14 β-lactams were evaluated. Combinations with amikacin demonstrated inhibitory synergistic activity in 29% of the assays, as compared with 22% for netilmicin (P = 0.018), 17% for gentamicin (P < 0.001), and 13% for tobramycin (P < 0.001). Among the β-lactams, combinations with cefoperazone, ceftriaxone, or cefpiramide (SM-1652) demonstrated inhibitory synergistic activity most often (39, 38, and 35% of the assays, respectively) and with ceforanide, cefsulodin, and imipenem least often (≤8% each). The most active combination was amikacin and ceftriaxone, with which 67% of the assays demonstrated inhibitory synergism. Isolates with high-level resistance to either antibiotic in a combination were unlikely to be inhibited synergistically by the combination. Further, combinations generally demonstrated little synergistic activity against isolates highly susceptible to β-lactams.
AB - We evaluated the in vitro synergistic activity at clinically attainable concentrations of combinations of aminoglycoside and β-lactam antibiotics against 30 gentamicin-resistant clinical isolates of gram-negative bacilli. All 56 pairs of 4 aminoglycosides and 14 β-lactams were evaluated. Combinations with amikacin demonstrated inhibitory synergistic activity in 29% of the assays, as compared with 22% for netilmicin (P = 0.018), 17% for gentamicin (P < 0.001), and 13% for tobramycin (P < 0.001). Among the β-lactams, combinations with cefoperazone, ceftriaxone, or cefpiramide (SM-1652) demonstrated inhibitory synergistic activity most often (39, 38, and 35% of the assays, respectively) and with ceforanide, cefsulodin, and imipenem least often (≤8% each). The most active combination was amikacin and ceftriaxone, with which 67% of the assays demonstrated inhibitory synergism. Isolates with high-level resistance to either antibiotic in a combination were unlikely to be inhibited synergistically by the combination. Further, combinations generally demonstrated little synergistic activity against isolates highly susceptible to β-lactams.
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U2 - 10.1128/AAC.26.4.535
DO - 10.1128/AAC.26.4.535
M3 - Article
C2 - 6517544
AN - SCOPUS:0021130382
VL - 26
SP - 535
EP - 538
JO - Antimicrobial Agents and Chemotherapy
JF - Antimicrobial Agents and Chemotherapy
SN - 0066-4804
IS - 4
ER -