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Acta Biologica Hungarica
Authors:
Ágnes Gallé
,
Zalán Czékus
,
Krisztina Bela
,
Edit Horváth
,
Jolán Csiszár
, and
Péter Poór

Although the participation of glutathione transferases (GSTs) in light-dependent pathways and the circadian changes in the whole detoxification system have been studied, there are fewer results regarding the exact daily fluctuation of GSTs. In the present study, it was demonstrated that light up-regulated, while dark period decreased the plant GST activity and the expression of the selected tau group GST genes in tomato. These findings provide additional information on our current knowledge on the circadian rhythm of GSTs in plants and could help in further defining detoxification processes.

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Arsenic affects large populations and attacks, among others, the nervous system. Waterborne or occupational exposure causes electrophysiological alterations and motor disturbances in humans, and analogous effects were found in animals. Certain phytochemicals may be protective against As-caused damages. In the present study it was investigated whether the flavonoid rutin, applied via the drinking water (2 g/L), ameliorates the effects of arsenic given by gavage (10 mg/kg b.w., in form of NaAsO2) on open field motility, evoked cortical and peripheral electrophysiological activity, and body weight gain in adult male Wistar rats. Body weight gain was significantly reduced from the 4th week of the 6 weeks arsenic treatment and this effect was largely abolished by rutin in the combination treatment group. Rats treated by arsenic alone showed decreased open field motility; latency of the cortical evoked potentials increased and peripheral nerve conduction velocity decreased. These functional alterations were also counteracted by co-administration of rutin, and both the antioxidant and the chelating activity of rutin might have contributed to the ameliorative effect. These results are apparently novel and support the potential role of natural agents in preserving human health in a contaminated environment.

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Acta Biologica Hungarica
Authors:
Edit Horváth
,
Krisztina Bela
,
Csaba Papdi
,
Ágnes Gallé
,
László Szabados
,
Irma Tari
, and
Jolán Csiszár

Arabidopsis thaliana contains 54 soluble glutathione transferases (GSTs, EC 2.5.1.18), which are thought to play major roles in oxidative stress responses, but little is known about the function of individual isoenzymes. The role of AtGST phi 9 (GSTF9) in the salt- and salicylic acid response was investigated using 2-week-old Atgstf9 and wild type (Wt) plants. Atgstf9 mutants accumulated more ascorbic acid (AsA) and glutathione (GSH) and had decreased glutathione peroxidase (GPOX) activity under control conditions. Treatment of 2-week-old seedlings with 10−7 M salicylic acid (SA) for 48 h resulted in elevated H2O2 level and enhanced GST activity in Atgstf9 plants, 10−5 M SA treatment enhanced the malondialdehyde and dehydroascorbate contents compared to Wt. 50 and 150 mM NaCl increased the GST activity, AsA and GSH accumulation in Atgstf9 seedlings more pronounced than in Wt plants. We found that the Atgstf9 mutants had altered redox homeostasis under control and stress conditions, in which elevated AsA and GSH levels and modified GST and GPOX activities may play significant role. The half-cell potential values calculated from the concentration of GSH and GSSG indicate that this GST isoenzyme has an important role in the salt stress response.

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European Journal of Microbiology and Immunology
Authors:
Péter Pallós
,
Márió Gajdács
,
Edit Urbán
,
Yvett Szabados
,
Klaudia Szalai
,
Lívia Hevesi
,
Anna Horváth
,
Anna Kuklis
,
Devina Morjaria
,
Wajiha Iffat
,
Helal F. Hetta
,
Nicola Piredda
, and
Matthew Gavino Donadu

Abstract

The clinical role of Acinetobacter baumannii has been highlighted in numerous infectious syndromes with a high mortality rate, due to the high prevalence of multidrug-resistant (MDR) isolates. The treatment and eradication of this pathogen is hindered by biofilm-formation, providing protection from noxious environmental factors and antimicrobials. The aim of this study was to assess the antibiotic susceptibility, antiseptic susceptibility and biofilm-forming capacity using phenotypic methods in environmental A. baumannii isolates. One hundred and fourteen (n = 114) isolates were collected, originating from various environmental sources and geographical regions. Antimicrobial susceptibility testing was carried out using the disk diffusion method, while antiseptic susceptibility was performed using the agar dilution method. Determination of biofilm-forming capacity was carried out using a microtiter-plate based method. Resistance in environmental A. baumannii isolates were highest for ciprofloxacin (64.03%, n = 73), levofloxacin (62.18%, n = 71) and trimethoprim-sulfamethoxazole (61.40%, n = 70), while lowest for colistin (1.75%, n = 2). Efflux pump overexpression was seen in 48.25% of isolates (n = 55), 49.12% (n = 56) were classified as MDR. 6.14% (n = 7), 9.65% (n = 11), 24.65% (n = 28) and 59.65% (n = 68) of isolates were non-biofilm producers, weak, medium, and strong biofilm producers, respectively. No significant differences were observed between non-MDR vs. MDR isolates regarding their distribution of biofilm-producers (P = 0.655). The MIC ranges for the tested antiseptics were as follows: benzalkonium chloride 16–128 μg mL−1, chlorhexidine digluconate 4–128 μg mL−1, formaldehyde 64–256 μg mL−1 and triclosan 2–16 μg mL−1, respectively. The conscientious use of antiseptics, together with periodic surveillance, is essential to curb the spread of these bacteria, and to maintain current infection prevention capabilities.

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