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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
6
|
| pubmed:dateCreated |
1990-1-23
|
| pubmed:abstractText |
Amiloride combined with subinhibitory concentrations of tobramycin is synergistic against Pseudomonas cepacia in vitro. It is known that amiloride blocks transmembrane sodium (Na+) flux in eukaryotic cells, but the mechanism of action in bacteria is unknown. Amiloride-mediated Na+ gradient changes might affect transcellular tobramycin transport, resulting in synergy between these two drugs. To examine this hypothesis, we studied the effect of extracellular [Na+] on amiloride-tobramycin synergy with a reference strain of P. cepacia. Control growth in Mueller-Hinton broth (MHB) alone, MHB supplemented with 200 mmol/L NaCl, and MHB dialyzed against a Na+-free solution was determined by absorbance at 650 nm over 3 hours. Inhibition in the presence of amiloride, tobramycin, or a combination was expressed as percentage of control growth. Growth in the presence of tobramycin alone was significantly higher in MHB + NaCl than in MHB or dialyzed MHB (81% +/- 5%; vs 57% +/- 5%; 35% +/- 4%; mean +/- SEM, respectively, p = 0.003). Growth in the presence of amiloride alone was not significantly different in the three media (84% +/- 4%; 80% +/- 3%; 80% +/- 1%; respectively, p = 0.746). Percent control growth was significantly lower when the two drugs were combined, but results were not statistically different among the three media (3.5% +/- 3%; 0.2% +/- 0.8%; 4% +/- 1%; respectively, p = 0.604). We conclude that growth inhibition of P. cepacia in the presence of tobramycin is antagonized by increasing extracellular [Na+]. This antagonistic effect of [Na+] is reversed by amiloride. Changes in [Na+] do not appear to directly affect amiloride-tobramycin synergy in P. cepacia.
|
| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
AIM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Dec
|
| pubmed:issn |
0022-2143
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
114
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
724-7
|
| pubmed:dateRevised |
2007-11-14
|
| pubmed:meshHeading | |
| pubmed:year |
1989
|
| pubmed:articleTitle |
The effect of sodium on amiloride-tobramycin synergy in Pseudomonas cepacia.
|
| pubmed:affiliation |
Department of Pediatrics, Children's Medical Center, Dayton, OH 45404.
|
| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
|