Impact of Long-Term Manure and Sewage Sludge Application to Soil as Organic Fertilizer on the Incidence of Pathogenic Microorganisms and Antibiotic Resistance Genes

The reuse of stabilized (under thermophilic conditions) sewage sludge and manure on agricultural soils is a common practice. The aim of this study was to evaluate the risks associated with their repeated applications on the spread of pathogenic bacteria and antibiotic resistance genes (ARGs) that encode resistance to tetracycline (tetA and tetW), sulphonamide (sul1 and sul2), erythromycin (ermB), vancomycin (vanA) and integron genetic element (intI1). The trial fields has been regularly fertilized every 3rd year since 1996 with manure (MF; 330 kg N/ha) and sewage sludge (SF; 330 kg N/ha and SF3; 990 kg N/ha). Unfertilized soil (CF) served as a control. Samples were collected at different time points: (i) right before fertilization (which was also 3 years after the last fertilization), (ii) 5 months after fertilization, and (iii) 11 months after fertilization. The relative abundance of amplicon sequence variants (ASVs) assigned to potentially pathogenic bacteria was low (0.3% and 0.25% in sludge and manure, respectively), and no association with the application of these fertilizers was found. On the other hand, our data indicate that an increased relative abundance of the ARGs sul1 and tetW was significantly associated with these fertilizer applications, and sul1 was increased in all treatments regardless of the time. It is suggested that sul1 should be monitored in organically fertilized soils to prevent its spread and possible further accumulation in crops

Factors Influencing the Fungal Diversity on Audio–Visual Materials

The biodeterioration of audio–visual materials is a huge problem, as it can cause incalculable losses. To preserve these cultural heritage objects for future generations, it is necessary to determine the main agents of biodeterioration. This study focuses on identifying fungi, both from the air and smears from photographs and cinematographic films that differ in the type of carrier and binder, using high-throughput sequencing approaches. The alpha diversity measures of communities present on all types of carriers were compared, and a significant difference between cellulose acetate and baryta paper was observed. Next, the locality, type of carrier, and audio–visual material seem to affect the structure of fungal communities. Additionally, a link between the occurrence of the most abundant classes and species on audio–visual materials and air contamination in the archives was proven. In both cases, the most abundant classes were Agariomycetes, Dothideomycetes, and Eurotiomycetes, and approximately half of the 50 most abundant species detected on the audio–visual materials and in the air were identical

Bacterial Diversity on Historical Audio-Visual Materials and in the Atmosphere of Czech Depositories

ABSTRACT Microbial contamination in cultural heritage storage facilities is undoubtedly still a huge problem and leads to the biodeterioration of historical objects and thus the loss of information for future generations. Most studies focus on fungi that colonize materials, which are the primary agents of biodeterioration. However, bacteria also play crucial roles in this process. Therefore, this study focuses on identifying bacteria that colonize audio-visual materials and those present in the air in the archives of the Czech Republic. For our purposes, the Illumina MiSeq amplicon sequencing method was used. Using this method, 18 bacterial genera with an abundance of higher than 1% were identified on audio-visual materials and in the air. We also evaluated some factors that were assumed to possibly influence the composition of bacterial communities on audio-visual materials, of which locality was shown to be significant. Locality also explained most of the variability in bacterial community structure. Furthermore, an association between genera colonizing materials and genera present in the air was demonstrated, and indicator genera were evaluated for each locality. IMPORTANCE The existing literature on microbial contamination of audio-visual materials has predominantly used culture-based methods to evaluate contamination and has overlooked the potential impact of environmental factors and material composition on microbial communities. Furthermore, previous studies have mainly focused on contamination by microscopic fungi, neglecting other potentially harmful microorganisms. To address these gaps in knowledge, our study is the first to provide a comprehensive analysis of bacterial communities present on historical audio-visual materials. Our statistical analyses demonstrate the critical importance of including air analysis in such studies, as airborne microorganisms can significantly contribute to the contamination of these materials. The insights gained from this study are not only valuable in developing effective preventive measures to mitigate contamination but also valuable in identifying targeted disinfection methods for specific types of microorganisms. Overall, our findings highlight the need for a more holistic approach to understanding microbial contamination in cultural heritage materials

Bakterialni degradace chlorbenzoovych kyselin

This PhD. thesis describes the isolation, characterization and identification of bacterial isolates that are capable of chlorobenzoate (CB) degradation. Chlorobenzoates are intermediates of polychlorinated biphenyls (PCB) biodegradation metabolic pathway in nature. Due to the low range of substrate specificity of formerly isolated strains (A7, A8, A18 and A19), new bacterial strains were obtained from PCB polluted area within the industrial plant Colorlak, Ltd. (Uherske Hradiste, Czech Republic). Four of them (UH133, UH222, UH1411 and UH1613) were found to be Gram-negative and the only one was characterized as a Gram-positive strain (UH82). Newly isolated strains together with the strains A7, A8, A18 and A19 that have been previously classified according to their biochemical properties as the strains of the genus Pseudomonas, were precisely genotypically characterized. In spite of 16S rDNA analysis the strains A7, A8, A18 and A19 were reclassified into the genus Alcaligenes. Gram-negative strains UH133, UH222, UH1411 and UH1613 were taxonomically identified as the genus Pandoraea. Gram-positive isolate UH82 was classified as being the strain of the genus Arthrobacter. For the precise characterization of biodegradation capabilities of Alcaligenes and Pandoraea strains, localisation of the genes responsible for chlorobenzoate degradation was performed. These genes are in the case of the strains belonging into the genus Alcaligenes localised on plasmid. The size of the plasmids was determined by agarose gel electrophoresis to be around 80 kbp. During the cultivation of these strains on nutrient rich medium, the plasmids were cured. This was accompanied by the loss of their biodegradation ability. On the other hand, at the strains belonging into the genus Pandoraea no plasmid was detected and also no mutant strains without the ability to degrade chlorobenzoates were found. The stability of this capability at Pandoraea strains leads into the conclusion that the genes are localized on the chromosome. Consequently, newly isolated strains of the genus Pandoraea were characterized in terms of their three enzymes of degradation pathway for chlorobenzoates - ortho-chlorobenzoate dioxygenase, chlorocatechol 1,2-dioxygenase and chloromuconate cycloisomerase. Phylogenetic comparison performed by Southern hybridization with two DNA probes (reductase, alpha-subunit) of the multienzyme complex of OHBD of Pseudomonas aeruginosa JB2 and DNA isolated from newly isolated strains showed high level of homology. Multienzyme complex OHBD of Pandoraea strains is thus similar to the reference strain JB2. Its similarity to Alcaligenes strains A7, A8, A18 and A19 has already been described. On the contrary, the genes for chlorocatechol 1,2-dioxygenase and chloromuconate cycloisomerase show closer similarity to the genes of chlorobenzenes degraders Pseudomonas chlororaphis RW71 and Pseudomonas sp. P51 and 3-chlorobenzoate degrader Ralstonia eutropha NH9, since their similarity to Pseudomonas aeruginosa JB2 genes was only 72%Available from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi

Microbial Communities in Soils and Endosphere of Solanum tuberosum L. and their Response to Long-Term Fertilization

An understanding of how fertilization influences endophytes is crucial for sustainable agriculture, since the manipulation of the plant microbiome could affect plant fitness and productivity. This study was focused on the response of microbial communities in the soil and tubers to the regular application of manure (MF; 330 kg N/ha), sewage sludge (SF; 330 and SF3x; 990 kg N/ha), and chemical fertilizer (NPK; 330-90-300 kg N-P-K/ha). Unfertilized soil was used as a control (CF), and the experiment was set up at two distinct sites. All fertilization treatments significantly altered the prokaryotic and fungal communities in soil, whereas the influence of fertilization on the community of endophytes differed for each site. At the site with cambisol, prokaryotic and fungal endophytes were significantly shifted by MF and SF3 treatments. At the site with chernozem, neither the prokaryotic nor fungal endophytic communities were significantly associated with fertilization treatments. Fertilization significantly increased the relative abundance of the plant-beneficial bacteria Stenotrophomonas, Sphingomonas and the arbuscular mycorrhizal fungi. In tubers, the relative abundance of Fusarium was lower in MF-treated soil compared to CF. Although fertilization treatments clearly influenced the soil and endophytic community structure, we did not find any indication of human pathogens being transmitted into tubers via organic fertilizers

Benefits of Polyamide Nanofibrous Materials: Antibacterial Activity and Retention Ability for <em>Staphylococcus Aureus</em>

Although nanomaterials are used in many fields, little is known about the fundamental interactions between nanomaterials and microorganisms. To test antimicrobial properties and retention ability, 13 electrospun polyamide (PA) nanomaterials with different morphology and functionalization with various concentrations of AgNO3 and chlorhexidine (CHX) were analyzed. Staphylococcus aureus CCM 4516 was used to verify the designed nanomaterials’ inhibition and permeability assays. All functionalized PAs suppressed bacterial growth, and the most effective antimicrobial nanomaterial was evaluated to be PA 12% with 4.0 wt% CHX (inhibition zones: 2.9 ± 0.2 mm; log10 suppression: 8.9 ± 0.0; inhibitory rate: 100.0%). Furthermore, the long-term stability of all functionalized PAs was tested. These nanomaterials can be stored at least nine months after their preparation without losing their antibacterial effect. A filtration apparatus was constructed for testing the retention of PAs. All of the PAs effectively retained the filtered bacteria with log10 removal of 3.3–6.8 and a retention rate of 96.7–100.0%. Surface density significantly influenced the retention efficiency of PAs (p ≤ 0.01), while the effect of fiber diameter was not confirmed (p ≥ 0.05). Due to their stability, retention, and antimicrobial properties, they can serve as a model for medical or filtration applications

Study of Cytotoxic Effects of Benzonitrile Pesticides

The benzonitrile herbicides bromoxynil, chloroxynil, dichlobenil, and ioxynil have been used actively worldwide to control weeds in agriculture since 1970s. Even though dichlobenil is prohibited in EU since 2008, studies addressing the fate of benzonitrile herbicides in the environment show that some metabolites of these herbicides are very persistent. We tested the cytotoxic effects of benzonitrile herbicides and their microbial metabolites using two human cell lines, Hep G2 and HEK293T, representing liver and kidneys as potential target organs in humans. The cell viability and proliferation were determined by MTT test and RTCA DP Analyzer system, respectively. The latter allows real-time monitoring of the effect of added substances. As the cytotoxic compounds could compromise cell membrane integrity, the lactate dehydrogenase test was performed as well. We observed high toxic effects of bromoxynil, chloroxynil, and ioxynil on both tested cell lines. In contrast, we determined only low inhibition of cell growth in presence of dichlobenil and microbial metabolites originating from the tested herbicides

Surface-PASylation of ferritin to form stealth nanovehicles enhances in vivo therapeutic performance of encapsulated ellipticine

Surface functionalisations substantially influence the performance of drug delivery vehicles by improving their biocompatibility, selectivity and circulation in bloodstream. Herein, we present the study of in vitro and in vivo behaviour of a highly potent cytostatic alkaloid ellipticine (Elli) encapsulated in internal cavity of ferritin (FRT)-based nanocarrier (hereinafter referred to as FRTElli). In addition, FRTElli surface was functionalised with three different molecular coatings: two types of protective PAS peptides (10- or 20-residues lengths) with sequences comprising amino acids proline (P), alanine (A) and serine (S) (to form PAS-10-FRTElli or PAS-20-FRTElli, respectively), or polyethylene glycol (PEG-FRTElli). All three surface modifications of FRT disposed sufficient encapsulation efficiency of Elli with no premature cumulative release of cargo. Noteworthy, all tested surface modifications displayed beneficial effects on the in vitro biocompatibility. PAS-10-FRTElli exhibited markedly reduced uptake by macrophages compared to PAS-20-FRTElli, PEG-FRTElli or unmodified FRTElli. The exceptional properties of PAS-10-FRTElli were validated by an array of in vitro analyses including formation of protein corona, uptake efficiency or screenings of selectivity of cytotoxicity. In murine preclinical model bearing triple-negative breast cancer (MDA-MB-231) xenograft, compared to free Elli or FRTElli, PAS-10-FRTElli displayed enhanced accumulation of Elli within tumour tissue, while hampering the uptake of Elli into off-target tissues. Noteworthy, PAS-10-FRTElli led to decreased in vivo complement (C3) activation and protein corona formation. Taken together, presented in vivo results indicate that PAS-10-FRTElli represents a promising stealth platform for translation into clinical settings.info:eu-repo/semantics/publishedVersio