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Klára Vlčková Jakub Kreisinger Barbora Pafčo Dagmar Čížková Nikki Tagg Adrian B. Hehl David Modrý 《International journal for parasitology》2018,48(7):519-530
Understanding the complex Entamoeba communities in the mammalian intestine has been, to date, complicated by the lack of a suitable approach for molecular detection of multiple variants co-occurring in mixed infections. Here, we report on the application of a high throughput sequencing approach based on partial 18S rDNA using the Illumina MiSeq platform. We describe, to our knowledge, for the first time, the Entamoeba communities in humans, free-ranging western lowland gorillas and central chimpanzees living in the Dja Faunal Reserve in Cameroon. We detected 36 Entamoeba haplotypes belonging to six haplotype clusters, containing haplotypes possessing high and low host specificity. Most of the detected haplotypes belonged to commensal Entamoeba, however, the pathogenic species (Entamoeba histolytica and Entamoeba nuttalli) were also detected. We observed that some Entamoeba haplotypes are shared between humans and other hosts, indicating their zoonotic potential. The findings are important not only for understanding the epidemiology of amoebiasis in humans in rural African localities, but also in the context of wild great ape conservation. 相似文献
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Hana Raschmanová Leona Paulová Barbora Branská Zdeněk Knejzlík Karel Melzoch Karin Kovar 《Folia microbiologica》2018,63(6):773-787
Pharmaceutical grade trypsin is in ever-increasing demand for medical and industrial applications. Improving the efficiency of existing biotechnological manufacturing processes is therefore paramount. When produced biotechnologically, trypsinogen—the inactive precursor of trypsin—is advantageous, since active trypsin would impair cell viability. To study factors affecting cell physiology and the production of trypsinogen in fed-batch cultures, we built a fusion protein of porcine trypsinogen and enhanced green fluorescent protein (EGFP) in Pichia pastoris. The experiments were performed with two different pH values (5.0 and 5.9) and two constant specific growth rates (0.02 and 0.04 1/h), maintained using exponential addition of methanol. All the productivity data presented rely on an active determination of trypsin obtained by proteolysis of the trypsinogen produced. The pH of the medium did not affect cell growth, but significantly influenced specific production of trypsinogen: A 1.7-fold higher concentration of trypsinogen was achieved at pH 5.9 (64 mg/L at 0.02 1/h) compared to pH 5.0. EGFP was primarily used to facilitate detection of intracellular protein over the biosynthetic time course. Using flow cytometry with fluorescence detection, cell disruption was avoided, and protein extraction and purification prior to analysis were unnecessary. However, Western blot and SDS-PAGE showed that cleavage of EGFP-trypsinogen fusion protein occurred, probably caused by Pichia-endogenous proteases. The fluorescence analysis did therefore not accurately represent the actual trypsinogen concentration. However, we gained new experimentally-relevant insights, which can be used to avoid misinterpretation of tracking and quantifying as well as online-monitoring of proteins with the frequently used fluorescent tags. 相似文献
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Naila Ferimazova Kristina Felcmanová Eva Šetlíková Hendrik Küpper Iris Maldener Günther Hauska Barbora Šedivá Ondřej Prášil 《Photosynthesis research》2013,116(1):79-91
Changes of photosynthetic activity in vivo of individual heterocysts and vegetative cells in the diazotrophic cyanobacterium Anabaena sp. strain PCC 7120 during the course of diazotrophic acclimation were determined using fluorescence kinetic microscopy (FKM). Distinct phases of stress and acclimation following nitrogen step-down were observed. The first was a period of perception, in which the cells used their internally stored nitrogen without detectable loss of PS II activity or pigments. In the second, the stress phase of nitrogen limitation, the cell differentiation occurred and an abrupt decline of fluorescence yield was observed. This decline in fluorescence was not paralleled by a corresponding decline in photosynthetic pigment content and PS II activity. Both maximal quantum yield and sustained electron flow were not altered in vegetative cells, only in the forming heterocysts. The third, acclimation phase started first in the differentiating heterocysts with a recovery of PS II photochemical yields $F_{\text{v}} /F_{\text{m}} ,\;F^{\prime}_{\text{v}} /F^{\prime}_{\text{m}}.$ F v / F m , F v ′ / F m ′ . Afterwards, the onset of nitrogenase activity was observed, followed by the restoration of antenna pigments in the vegetative cells, but not in the heterocysts. Surprisingly, mature heterocysts were found to have an intact PS II as judged by photochemical yields, but a strongly reduced PS II-associated antenna as judged by decreased F 0. The possible importance of the functional PS II in heterocysts is discussed. Also, the FKM approach allowed to follow in vivo and evaluate the heterogeneity in photosynthetic performance among individual vegetative cells as well as heterocysts in the course of diazotrophic acclimation. Some cells along the filament (so-called “superbright cells”) were observed to display transiently increased fluorescence yield, which apparently proceeded by apoptosis. 相似文献
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Barbora Servusová Jana Vobicková Pavla Paterová Vladimír Kubíček Jiří Kuneš Martin Doležal Jan Zitko 《Bioorganic & medicinal chemistry letters》2013,23(12):3589-3591
To develop new potential antimycobacterial drugs, a series of pyrazinamide derivatives was designed, synthesized and tested for their ability to inhibit the growth of selected mycobacterial strains (Mycobacterium tuberculosis H37Rv, Mycobacterium kansasii and two strains of Mycobacterium avium). This Letter is focused on binuclear pyrazinamide analogues containing the –CONH–CH2– bridge, namely on N-benzyl-5-chloropyrazine-2-carboxamides with various substituents on the phenyl ring and their comparison with some analogously substituted 5-chloro-N-phenylpyrazine-2-carboxamides. Compounds from the N-benzyl series exerted lower antimycobacterial activity against M. tuberculosis H37Rv then corresponding anilides, however comparable with pyrazinamide (12.5–25 μg/mL). Remarkably, 5-chloro-N-(4-methylbenzyl)pyrazine-2-carboxamide (8, MIC = 3.13 μg/mL) and 5-chloro-N-(2-chlorobenzyl)pyrazine-2-carboxamide (1, MIC = 6.25 μg/mL) were active against M. kansasii, which is naturally unsusceptible to PZA. Basic structure–activity relationships are presented. 相似文献
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Eva Nemcova Michaela Cernochova Filip Ruzicka Barbora Malisova Tomas Freiberger Petr Nemec 《PloS one》2015,10(2)
An increasing trend in non albicans infections and various susceptibility patterns to antifungal agents implies a requirement for the quick and reliable identification of a number of medically important Candida species. Real-time PCR followed by high resolution melting analysis (HRMA) was developed, tested on 25 reference Candida collection strains and validated on an additional 143 clinical isolates in this study. All reference strains and clinical isolates inconclusive when using phenotypic methods and/or HRMA were analysed using ITS2 sequencing. Considering reference and clinical strains together, 23 out of 27 Candida species could be clearly distinguished by HRMA, while the remaining 4 species were grouped in 2 pairs, when applying the mean Tm ± 3 SD values, the shape of the derivative melting curve (dMelt curve) and, in some cases, the normalized and temperature—shifted difference plot against C. krusei. HRMA as a simple, rapid and inexpensive tool was shown to be useful in identifying a wide spectrum of clinically important Candida species. It may complement the current clinical diagnostic approach based on commercially available biochemical kits. 相似文献
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Zbynek Heger Petr Michalek Roman Guran Barbora Havelkova Marketa Kominkova Natalia Cernei Lukas Richtera Miroslava Beklova Vojtech Adam Rene Kizek 《PloS one》2015,10(12)