Application Potential of Trichoderma in the Degradation of Phenolic Acid-Modified Chitosan.

The aim of the study was to determine the potential use of fungi of the genus Trichoderma for the degradation of phenolic acid-modified chitosan in compost. At the same time, the enzymatic activity in the compost was checked after the application of a preparation containing a suspension of the fungi Trichoderma (spores concentration 105/mL). The Trichoderma strains were characterized by high lipase and aminopeptidase activity, chitinase, and ß-1,3-glucanases. T. atroviride TN1 and T. citrinoviride TN3 metabolized the modified chitosan films best. Biodegradation of modified chitosan films by native microorganisms in the compost was significantly less effective than after the application of a formulation composed of Trichoderma TN1 and TN3. Bioaugmentation with a Trichoderma preparation had a significant effect on the activity of all enzymes in the compost. The highest oxygen consumption in the presence of chitosan with tannic acid film was found after the application of the consortium of these strains (861 mg O2/kg after 21 days of incubation). Similarly, chitosan with gallic acid and chitosan with ferulic acid were found after the application of the consortium of these strains (849 mgO2/kg and 725 mg O2/kg after 21 days of incubation). The use of the Trichoderma consortium significantly increased the chitinase activity. The application of Trichoderma also offers many possibilities in sustainable agriculture. Trichoderma can not only degrade chitosan films, but also protect plants against fungal pathogens by synthesizing chitinases and ß-1,3 glucanases with antifungal properties.

Detection, characterization, and antimicrobial susceptibility of Yersinia enterocolitica in different types of wastewater in the Czech Republic.

AIMS: The purpose of the study was to evaluate the occurrence of Yersinia enterocolitica in different types of wastewater and to characterize the isolates by biotyping, serotyping, and antimicrobial susceptibility testing. In addition, cultivation protocols were evaluated. METHODS AND RESULTS: The occurrence of Y. enterocolitica was determined in treated and untreated municipal wastewater, as well as in hospital, slaughterhouse, and cowshed wastewater. Y. enterocolitica was detected in 84.1% of the wastewater samples, while the main sources were untreated municipal and slaughterhouse wastewater. In contrast, the lowest incidence was found in hospital wastewater. An exclusive occurrence of biotype 1A (98.3%) was detected. Pathogenic bio-serotypes 4/O:3 and 3/O:3 were isolated only from slaughterhouse wastewater. The highest resistance rates were observed for ampicillin (92.5%) and amoxicillin-clavulanic acid (36.8%). CONCLUSIONS: Y. enterocolitica was commonly detected in wastewater, although the prevalence varied depending on the origin of the wastewater. No single cultivation protocol was able to recover Y. enterocolitica isolates from such a complex matrix as wastewater. SIGNIFICANCE AND IMPACT OF THE STUDY: Our study provided data that can contribute to the evaluation of wastewater as a source of Y. enterocolitica and to understanding the threat of wastewater isolates to human health.

Antibiotic resistance of Pseudomonas aeruginosa isolated from hospital wastewater in the Czech Republic.

Resistant bacteria may leave the hospital environment through wastewater. The opportunistic pathogen Pseudomonas aeruginosa, due to its intrinsic resistance to many antibiotics and its ability to easily acquire antibiotic resistance determinants, poses a significant threat to public health. The aim of this study was to evaluate the antibiotic resistance profiles of cultivated P. aeruginosa in untreated hospital effluents in the Czech Republic. Fifty-nine P. aeruginosa strains isolated from six hospital wastewaters were tested for antimicrobial susceptibility through the disc diffusion method against seven antimicrobial agents. Resistance was found in all antibiotics tested. The highest resistance values were observed for ciprofloxacin (30.5%), gentamicin (28.8%), and meropenem (27.2%). The P. aeruginosa isolates also exhibited resistance to ceftazidime (11.5%), amikacin (11.5%), piperacillin-tazobactam (11.5%), and aztreonam (8.5%). Seventeen strains of P. aeruginosa (28.8%) were classified as multidrug-resistant (MDR). The results of this study revealed that antibiotic-resistant strains are commonly present in hospital wastewater and are resistant to clinically relevant antipseudomonal drugs. In the absence of an appropriate treatment process for hospital wastewater, resistant bacteria are released directly into public sewer networks, where they can serve as potential vectors for the spread of antibiotic resistance.

The Effect of Antibiotics on Planktonic Cells and Biofilm Formation Ability of Collected Arcobacter-like Strains and Strains Isolated within the Czech Republic.

The purpose of this study was to test the in vitro effects of ampicillin, ciprofloxacin, clindamycin, erythromycin, gentamicin, and tetracycline on planktonic cells of Arcobacter-like microorganisms and on their biofilm formation ability. The minimum inhibitory concentrations (MICs) were determined by the microdilution method. Further, biofilm formation ability in the presence of various concentrations of antibiotics was evaluated by a modified Christensen method. Most of the 60 strains exhibited high susceptibility to gentamicin (98.3%), ciprofloxacin (95.0%), and erythromycin (100.0%). High level of resistance was observed to clindamycin and tetracycline with MIC50 and MIC90 in range of 4-32 mg/L and 32-128 mg/L, respectively. Combined resistance to both clindamycin and tetracycline was found in 38.3% of tested strains. In general, higher biofilm formation was observed especially at lower concentrations of antibiotics (0.13-2 mg/L). However, a significant decrease in biofilm formation ability of Pseudarcobacter defluvii LMG 25694 was exhibited with ampicillin and clindamycin at concentrations above 32 or 8 mg/L, respectively. Biofilm formation represents a potential danger of infection and also a risk to human health, in particular due to antimicrobial-resistant strains and the ability to form a biofilm structure at a concentration that is approximately the MIC determined for planktonic cells.

Chemical Composition of Natural Hydrolates and Their Antimicrobial Activity on Arcobacter-Like Cells in Comparison with Other Microorganisms.

Hydrolates obtained via the hydrodistillation and steam distillation of Lavandulaangustifolia Mill., Syzygiumaromaticum L., Foeniculumvulgare Mill., and Laurusnobilis L. were analyzed by gas chromatography with flame ionization detector (GC-FID) and gas chromatography coupled to mass spectrometry (GC-MS). Additionally, the hydrolates were evaluated for antimicrobial activity (disk-diffusion and microdilution method), influence on biofilm formation (Christensen method) and cytotoxicity of concentrated hydrolates against human cell lines (A549) by xCELLigence system. Using chemical analysis, 48, 9, 13 and 33 different components were detected in lavender, clove, fennel and laurel hydrolates, respectively. Lavender hydrolate contained the largest proportion of 1,8-cineol, linalool furanoxide, and linalool. The main components of laurel hydrolate were 1,8-cineol, 4-terpineol and α-terpineol. Fenchone and estragole were the most abundant in fennel hydrolate, and eugenol and eugenyl acetate in clove hydrolate. Concentrated hydrolates showed significant antimicrobial activity. Clove hydrolate was among the most antimicrobially active agents, most preferably against C. albicans, with an inhibition zone up to 23.5 mm. Moreover, concentrated hydrolates did not show any cytotoxic effect again8 st human A549 cells. In the presence of the non-concentrated hydrolates, significantly reduced biofilm formation was observed; however, with concentrated clove hydrolate, there was an increase in biofilm formation, e.g., of A. thereius, A. lanthieri, and A. butzleri. Research shows new findings about hydrolates that may be important in natural medicine or for preservation purposes.

Susceptibility to 18 drugs and multidrug resistance of Arcobacter isolates from different sources within the Czech Republic.

OBJECTIVES: Arcobacter spp. are considered to be potential foodborne pathogens, and consumption of contaminated food containing these bacteria could endanger human and animal health. Arcobacter butzleri and Arcobacter cryaerophilus are the species most frequently isolated from food of animal origin and from other samples. The aim of this study was to evaluate the susceptibility of arcobacters isolated in the Czech Republic. No information about antibiotic susceptibility and multidrug resistance of arcobacters isolated in the Czech Republic is available in the literature before now. METHODS: The antimicrobial resistance of A. butzleri (n=80) and A. cryaerophilus (n=20) isolated from meat of animal origin, water sources and clinical samples was examined by the disk diffusion method. RESULTS: Arcobacters were resistant to one or more antimicrobial agents in 99% (99/100) of tested isolates. Most of the Arcobacter isolates were resistant to ß-lactam antibiotics, i.e. ampicillin (81.0%), amoxicillin/clavulanic acid (28.0%), cefalotin (73.0%) and aztreonam (93.0%). Arcobacters were also frequently resistant to lincosamides, i.e. clindamycin (98.0%). Of the aminoglycosides, amikacin, gentamicin and tobramycin were evaluated to be the most effective antibiotics among those tested against arcobacters. CONCLUSIONS: These results demonstrate substantial resistance in Arcobacter isolates to 18 antimicrobial agents commonly used in medical and veterinary medicine. Multidrug resistance was found in 93.8% (75/80) of A. butzleri isolates and 70.0% (14/20) of A. cryaerophilus isolates.

Synthesis, structural characterization, docking, lipophilicity and cytotoxicity of 1-[(1R)-1-(6-fluoro-1,3-benzothiazol-2-yl)ethyl]-3-alkyl carbamates, novel acetylcholinesterase and butyrylcholinesterase pseudo-irreversible inhibitors.

In the current study, sixteen novel derivatives of (R)-1-(6-fluorobenzo[d]thiazol-2-yl)ethanamine were synthesized as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors. Chemical structures together with purity of the synthesized compounds were substantiated by IR, (1)H, (13)C, (19)F NMR, high resolution mass spectrometry and elemental analysis. The optical activities were confirmed by optical rotation measurements. The synthesized compounds were evaluated for their AChE and BChE inhibitory activities. In addition, the cytotoxicity of the most active compounds was investigated against human cell lines employing XTT tetrazolium salt reduction assay and xCELLigence system allowing a label-free assessment of the cells proliferation. Our results demonstrated that the inhibitory mechanism was confirmed to be pseudo-irreversible, in line with previous studies on carbamates. Compounds indicated as 3b, 3d, 3l and 3n showed the best AChE inhibitory activity of all the evaluated compounds and were up to tenfold more potent than standard drug rivastigmine. The binding mode was determined using state-of-the-art covalent docking and scoring methodology. The obtained data clearly demonstrated that 3b, 3d, 3l and 3n benzothiazole carbamates possess high inhibitory activity against AChE and BChE and concurrently negligible cytotoxicity. In conclusion, our results indicate, that these derivatives could be promising in an effective therapeutic intervention for Alzheimer's disease.

Persistence of Arcobacter butzleri CCUG 30484 on plastic, stainless steel and glass surfaces / Persistência de Arcobacter butzleri CCUG 30404 em superfícies de plástico, aço inox e vidro

The persistence of A. butzleri CCUG 30484 on various surfaces under 32 percent and 64 percent relative humidity suspended in physiological saline or nutrient broth to simulate relatively clean or soiled conditions was studied using various isolation techniques. Our study revealed that A. butzleri CCUG 30484 cells were able to survive for a considerable period of time, even after the droplet of suspending medium has been visibly dried. An extended survival on polypropylene coupons at both humidity levels was observed, particularly at soiled conditions.

Estudou-se a persistência de Arcobacter butzleri CCUG 30404 em várias superfícies de contato com alimentos a 32 por cento e 64 por cento de umidade relativa, suspenso em salina fisiológica e caldo nutriente para simular condições limpas e sujas. Nosso estudo indicou que A. butzleri CCUG 30404 foi capaz de sobreviver por longo tempo, mesmo após a secagem da gota. Observou-se que a sobrevivência for mais prolongada nos cupons de polipropileno, especialmente em condições sujas.

Antimicrobial effect of oxidized cellulose salts.

Antimicrobial properties of oxidized cellulose and its salts in linters (-L) and microsphere (-M) form (OKCEL H-L, OKCEL Zn-M, OKCEL ZnNa-L, OKCEL ZnNa-M and OKCEL Ag-L) were tested by a dilution method against a spectrum of microbial strains: Escherichia coli, Pseudomonas aeruginosa, Staphylococcus epidermidis, Bacillus licheniformis, Aspergillus niger, Penicillium chrysogenum, Rhizopus oryzae, Scopulariopsis brevicaulis, Candida albicans and Candida tropicalis. OKCEL Ag-L exhibited antimicrobial activity in the range 0.1-3.5% w/v against all the bacteria and fungi involved in this study. Strong inhibition by OKCEL ZnNa-M was observed for Staphylococcus epidermidis, Bacillus licheniformis, Rhizopus oryzae, Candida albicans and Candida tropicalis in the range 0.5-2.0% w/v. Antimicrobial effects of oxidized cellulose and its salts in textile form were investigated by a diffusion and dilution method against the spectrum of above-cited microbial strains extended by Clostridium perfringens. Generally, OKCEL Ag-T, OKCEL Zn-T and OKCEL H-T showed high antimicrobial activity against populations of Pseudomonas aeruginosa, Bacillus licheniformis and Staphylococcus epidermidis. OKCEL Zn-T was the only sample suppressing the growth of species.

Inhibition of Arcobacter butzleri, Arcobacter cryaerophilus, and Arcobacter skirrowii by plant oil aromatics.

The inhibitory effect of some plant oil aromatics against three strains of Arcobacter butzleri, two strains of Arcobacter cryaerophilus, and one strain of Arcobacter skirrowii was evaluated. When MICs were determined using the broth macrodilution method, cinnamaldehyde was most inhibitory followed by thymol, carvacrol, caffeic acid, tannic acid, and eugenol (P < 0.001). Sublethal concentrations of the three most potent plant oil aromatics also were examined. Overall, cinnamaldehyde was the most bacteriostatic against all arcobacters tested except A. butzleri when these strains were exposed to the MIC25 of this aromatic aldehyde. The bacteriostatic activities of thymol and carvacrol were concentration and species dependent.

Quantitative analysis of expression level of BCL2 and BAX genes in Hep-2 and HL-60 cells after treatment with etoposide.

Apoptotic cell death is a highly regulated process, which plays a crucial role in many biological events. The aim of the present research was to investigate the expression of the apoptosis related genes BCL2 and BAX in Hep-2 and HL60 cells. Apoptosis was induced in these cell lines during treatment with etoposide. The expression levels of BCL2 and BAX genes were measured after 6 h and 12 h of treatment by quantitative real-time RT-PCR. In Hep-2 cells the expression level of BCL2 significantly increased both 6 h and 12 h of treatment, whereas expression level of BAX didn't change. In HL-60 cells the expression level of BCL2 decreased after 6 h of treatment and expression of BAX increased both 6 h and 12 h of treatment with etoposide. Those findings show distinct reactions of Hep-2 and HL-60 cells to etoposide treatment and different upregulation or downregulation of apoptosis-related genes BCL2 and BAX.

Persistence of Arcobacter butzleri CCUG 30484 on plastic, stainless steel and glass surfaces.

The persistence of A. butzleri CCUG 30484 on various surfaces under 32% and 64% relative humidity suspended in physiological saline or nutrient broth to simulate relatively clean or soiled conditions was studied using various isolation techniques. Our study revealed that A. butzleri CCUG 30484 cells were able to survive for a considerable period of time, even after the droplet of suspending medium has been visibly dried. An extended survival on polypropylene coupons at both humidity levels was observed, particularly at soiled conditions.

Inhibitory effects of some spice and herb extracts against Arcobacter butzleri, A. cryaerophilus, and A. skirrowii.

Seventeen spice and medicinal plant extracts (methanol and chloroform) were assayed for their antimicrobial activity against Arcobacter butzleri, A. cryaerophilus, and A. skirrowii. In general, all of the tested extracts were able, to a different extent, to inhibit the growth of the selected Arcobacter species. Cinnamon, bearberry, chamomile, sage and rosemary extracts showed strong antimicrobial activity toward arcobacter strains tested. Overall, the methanol extracts showed better activity than the chloroform extracts (P < 0.05); however, enhanced antibacterial activity of chloroform extracts of cinnamon and rosemary has been observed in comparison with their methanol counterparts. The inhibitory dose of the most active extracts (the diameter of zone of inhibition > or = 20 mm) was determined using the disc-diffusion method as well.