Ventriculitis due to Staphylococcus lugdunensis: two case reports

Staphylococcus lugdunensis is an unusually virulent coagulase-negative staphylococcus that has rarely been implicated in central nervous system infections

Application of HPLC to meropenem determination on plasma samples of patients with infections treated after coronary artery bypass graft surgery

W przeprowadzonych badaniach oceniano skuteczność dawkowania meropenemu stosowanego leczniczo w terapii zakażeń po przebytym zabiegu pomostowania aortalno-wieńcowego na podstawie analizy stężeń antybiotyku w próbkach osocza krwi pacjentów oznaczonych metodą HPLC. Celem pracy było wyznaczenie wartości parametrów farmakokinetycznych meropenemu w osoczu krwi pacjentów po wielokrotnym podaniu antybiotyku dożylnie, a ponadto ocena wartości stężeń meropenemu w odniesieniu do MIC patogénnych bakterii. Materiał biologiczny pobierano do badań w 2; 4; 5 i 6 dobie antybiotykoterapii. Proces izolacji meropenemu z próbek osocza krwi prowadzono techniką ekstrakcji do fazy stałej. Warunki analizy chromatograficznej antybiotyku uwzględniały zastosowanie kolumny LiChrisopher 100 RP-18 (5 µm, 250mm x 4mm);fazy ruchomej o składzie buforfosforanowy pH 7,0/acetonitryl (92:8); detektora DAD, długość fali 296 nm. Stężenie maksymałne meropenemu w stanie stacjonarnym (Cssmax) w 2 dobie antybiotykoterapii 0,25 h po podaniu kolejnej dawki leku wynosiło 17,58 µg/ml. W próbkach osocza krwi pobranych pod koniec przedziału dawkowania (8h) w kolejnych dobach terapii nie stwierdzono obecności leku. Tylko u jednego pacjenta stężenie minimalne w stanie stacjonarnym (Cssmax) wynosiło 0,87-0,89 µg/ml i przekraczało MIC Staphylococcus aureus, Enterobacter, Escherichia coli і Serratia. Należy rozważyć skrócenie częstości dawkowania antybiotyku celem zabezpieczenia terapeutycznych wartości stężeń.In performed study the effectiveness of meropenem administration was estimated after therapeutic using in infections treatment after coronary artery bypass graft surgery on the base of antibiotic concentrations determined by HPLC method in the plasma samples of patients. The aim of the present study was to determine pharmacokinetic parameters of meropenem in patients 'plasma samples after multiple intravenous antibiotic administration and the estimation of meropenem concentrations to MIC of bacterial patogens. The biological material to our study was taken in 2; 4; 5 and 6 day of the antibiotic therapy. The solid phase extraction was used to the isolation of meropenem from the plasma samles. Applied chromatographic conditions of antibiotic included the column LiChrisopher 100 RP-18 (5 µm, 250mm x 4mm); the mobile phase comprised phpsphate buffer pH 7,0/acetonitrile (92:8); DAD with detection at 296 nm. The maximal meropenem concentration in the steady state (Cssmax) in 2 day of treatment 0,25 h after administration of the next dose of antibiotic was 17,58 µg/ml. In the plasma samples which were taken in the end of the dosage regimen (8h) in subsequent days the antibiotic was not fund. Only in one patient the minimal concentration in the steady state (Cssmax) was 0,87-0,89 µg/ml and exceeded MIC for Staphylococcus aureus, Enterobacter, Escherichia coli і Serratia. The shorter frequency of drug administration has to be consider to assure the therapeutic range of antibiotic concentrations

Determination of the lipophilicity of quinolinesulfonamides by reversed-phase HPLC and theoretical calculations

<p>Reversed-phase high-performance liquid chromatography analyses were used for the determination of the retention factor (log <i>k</i>) of a set of quinolinesulfonamides. The analyses utilized a mixture of acetonitrile/water as the mobile phase. The log <i>k</i> values were linearly dependent on the concentration of acetonitrile and extrapolated to 100% water and gave the lipophilicity parameter log <i>k</i>_w. The parameter log <i>P</i>_HPLC was determined from log <i>k</i>_w values using the calibration curve obtained for five standards. The log <i>P</i>_HPLC parameters are discussed in terms of structure–lipophilicity relationships. Furthermore, the theoretical lipophilic parameters (log <i>P</i>_calc) for all compounds were calculated using chemical programs (e.g., Advanced Chemistry Development (ACD/ logP), miLogP, AlogP, ClogP, and Pallas). The determined log <i>P</i>_HPLC and calculated log <i>P</i>_calc values were compared by linear regression analysis.</p