The effect of aminoglycoside antibiotics (amikacin, gentamicin, netilmicin and tobramycin) at sublethal concentrations (sub-MICs) on some properties of Plesiomonas shigelloides strains was evaluated. All agents decreased the bacterial surface hydrophobicity. Amikacin (1/4 of the MIC) and netilmicin (1/4 and 1/8 of the MIC) changed the hydrophobic character of P. shigelloides surface to a hydrophilic one. Treatment of the strains with aminoglycosides decreased also motility, netilmicin being the most effective. No significant changes were found in lipolytic activity of antibiotic-treated strains. In the majority of cases aminoglycosides increased sensitivity of bacteria to hydrogen peroxide. The tested antibiotics did not induce production of short-chained N-acylhomoserine lactones signal molecules. Aminoglycosides at sub-MICs affected important activities of P. shigelloides potentially associated with their virulence in dependence on strain, antibiotic and concentration.

• MeSH
• amikacin farmakologie   MeSH
• antibakteriální látky farmakologie   MeSH
• gentamiciny farmakologie   MeSH
• hydrofobní a hydrofilní interakce MeSH
• mikrobiální testy citlivosti MeSH
• netilmicin farmakologie   MeSH
• oxidační stres MeSH
• Plesiomonas účinky léků   růst a vývoj   metabolismus   MeSH
• polysorbáty metabolismus   MeSH
• povrchově aktivní látky metabolismus   MeSH
• tobramycin farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• amikacin MeSH
• antibakteriální látky MeSH
• gentamiciny MeSH
• netilmicin MeSH
• polysorbáty MeSH
• povrchově aktivní látky MeSH
• tobramycin MeSH

Effect of magnesium, calcium and EDTA on slime production by 15 slime-positive and 13 slime-negative Staphylococcus epidermidis strains isolated from various clinical specimens was determined. The slime production on tryptic soy broth was significantly enhanced after addition of 128 mumol/L Mg2+. Similarly, the addition of Ca2+ caused a significant increase in slime production of all tested strains when concentration of Ca2+ exceeded 64 mumol/L. In contrast, in the presence of EDTA the slime production by all strains was significantly reduced. Hence Ca2+ and Mg2+ increase slime production of S. epidermidis. This finding is important in the context of the pathogenesis of biomedical implant infections caused by S. epidermidis.

• MeSH
• bakteriální adheze MeSH
• biofilmy MeSH
• chelátory farmakologie   MeSH
• EDTA farmakologie   MeSH
• hořčík farmakologie   MeSH
• Staphylococcus epidermidis účinky léků   metabolismus   MeSH
• vápník farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chelátory MeSH
• EDTA MeSH
• hořčík MeSH
• vápník MeSH

The impact of postantibiotic effect (PAE) of carbapenems (imipenem, meropenem) on the metabolism (biosynthesis of macromolecules, respiration), cell-surface hydrophobicity and motility of a clinical isolate of Enterobacter cloacae was examined. The metabolism was evaluated after 16 h and after 1 d of cultivation using 2x and 4x minimum inhibitory concentrations (MIC) of both antibiotics for the induction of PAE. Imipenem at 4 x MIC did not induce PAE. After a 16-h cultivation (in the postantibiotic phase of both carbapenems), inhibition of nucleosynthesis and protein synthesis was found; after a 1-d cultivation, during regrowth stimulation of mainly 14C-leucine incorporation was found. The presence of the exogenous intermediates of citrate cycle, viz. 2-oxoglutarate, increased the respiratory activity of the cells. The cell-surface hydrophobicity (evaluated by three methods--bacterial adhesion to hydrocarbon, nitrocellulose-filter test and salt-aggregation test) decreased after PAE of both carbapenems; meropenem was more effective. Motility (an important virulence factor) was inhibited in the postantibiotic phase of both carbapenems; the 4 x MIC caused a higher inhibition.

• MeSH
• časové faktory MeSH
• Enterobacter cloacae chemie   účinky léků   fyziologie   MeSH
• hydrofobní a hydrofilní interakce MeSH
• imipenem farmakologie   MeSH
• karbapenemy farmakologie   MeSH
• lidé MeSH
• meropenem MeSH
• pohyb účinky léků   MeSH
• thienamyciny farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• imipenem MeSH
• karbapenemy MeSH
• meropenem MeSH
• thienamyciny MeSH