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Comparison of Hungarianground red paprika volatiles of known origin (identical to cultivated varietiesgrown in Kalocsa, Hungary) and provenance has been performed following simultaneous distillation-extraction sample preparation. After polar phase capillary gas-chromatography, mass spectrometric identification of as many compounds as possible was carried out to precisely describe the aroma profile of the cultivars. For conceptualizing the results a data evaluation and interpretation method has been elaborated considering the component ratios that are much more characteristic of the cultivars than the absolute amounts themselves. Relative intensity interpretation of the peak areas (y-axis) and Programmed Temperature Retention Index (x-axis) measurement resulted in aromagrams individually characteristic of the cultivated varieties. In an identification experiment the cultivars have been recognized successfully by the graphic visualization of the results called aroma-spectra (by analogy to mass spectrometry) method.

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European Journal of Microbiology and Immunology
Authors:
Isabel Stephany-Brassesco
,
Stefan Bereswill
,
Markus M. Heimesaat
, and
Matthias F. Melzig

Antibiotic resistance of Streptococcus pneumoniae has risen to worrying levels in the past few decades worldwide, and subsequently, effective treatment of respiratory tract infections has become even more challenging. While the need to develop new strategies to combat bacterial infections is urgent, novel antibiotic compounds are no longer a priority of the pharmaceutical industry. However, resistance-modifying agents can alleviate the spread of antibiotic resistance and render existing antibiotics effective again. In the present study, we aimed to determine the combinatory antimicrobial effects of the commercial herbal product Cefabronchin® and antibiotic compounds, such as amoxicillin and clarithromycin, on 6 clinical isolates of S. pneumoniae. Therefore, the minimal inhibitory concentration (MIC) of each agent before and after adding Cefabronchin® at different concentrations was determined by applying the checkerboard method. Sub-inhibitory concentrations of the added Cefabronchin® were found to reduce the MIC down to between 3.4% and 29.2% of the amoxicillin MIC and down to between 10.4% and 45.8% of the clarithromycin MIC in all 6 strains. In conclusion, this study provides evidence for the improved antimicrobial effects of commonly used antibiotics in combination with Cefabronchin® in order to combat infections with antibiotic-resistant S. pneumoniae strains.

Open access
Acta Microbiologica et Immunologica Hungarica
Authors:
Lei Shi
,
Tanja Stachon
,
Lorenz Latta
,
Mohamed Ibrahem Elhawy
,
Gubesh Gunaratnam
,
Erika Orosz
,
Albrecht F. Kiderlen
,
Berthold Seitz
,
Markus Bischoff
, and
Nóra Szentmáry

We aimed to compare LDH release assay, trypan blue and fluorescent stainings, and non-nutrient Escherichia coli plate assay in determining treatment efficacy of antiamoebic agents against Acanthamoeba castellanii trophozoites/cysts, in vitro. 1BU trophozoites/cysts were challenged with 0.02% polyhexamethylene biguanid (PHMB), 0.1% propamidine isethionate (PD), and 0.0065% miltefosine (MF). Efficacies of the drugs were determined by LDH release and trypan blue assays, by Hoechst 33343, calcein-AM, and ethidium homodimer-1 fluorescent dyes, and by a non-nutrient agar E. coli plate assay. All three antiamoebic agents induced a significant LDH release from trophozoites, compared to controls (p < 0.0001). Fluorescent-dye staining in untreated 1BU trophozoites/cysts was negligible, but using antiamoebic agents, there was 59.3%–100% trypan blue, 100% Hoechst 33342, 0%–75.3% calcein-AM, and 100% ethidium homodimer-1 positivity. On E. coli plates, in controls and MF-treated 1BU trophozoites/cysts, new trophozoites appeared within 24 h, encystment occurred after 5 weeks. In PHMB- and PD-treated 1BU throphozoites/cysts, irregularly shaped, smaller trophozoites appeared after 72 h, which failed to form new cysts within 5 weeks. None of the enzymatic- and dye-based viability assays tested here generated survival rates for trophozoites/cysts that were comparable with those yielded with the non-nutrient agar E. coli plate assay, suggesting that the culture-based assay is the best method to study the treatment efficacy of drugs against Acanthamoeba.

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