Although Campylobacter jejuni is the pathogen responsible for the most common foodborne illness, tracing of the infection source remains challenging due to its highly variable genome. Therefore, one of the aim of the study was to compare three genotyping methods (MLST, PFGE, and mP-BIT) to determine the most effective genotyping tool. C. jejuni strains were divided into 4 clusters based on strain similarity in the cgMLST dendrogram. Subsequently, the dendrograms of the 3 tested methods were compared to determine the accuracy of each method compared to the reference cgMLST method. Moreover, a cost-benefit analysis has showed that MLST had the highest inverse discrimination index (97%) and required less workflow, time, fewer consumables, and low bacterial sample quantity. PFGE was shown to be obsolete both because of its low discriminatory power and the complexity of the procedure. Similarly, mP‐BIT showed low separation results, which was compensated by its high availability. Therefore, our data showed that MLST is the optimal tool for genotyping C. jejuni. Another aim was to compare the antimicrobial resistance to ciprofloxacin, erythromycin, and tetracycline in C. jejuni strains isolated from human, water, air, food, and animal samples by two gene sequence-based prediction methods and to compare them with the actual susceptibility of C. jejuni strains using the disc diffusion method. Both tools, ResFinder and RGI, synchronously predict the antimicrobial susceptibility of C. jejuni and either can be used.
- MeSH
- antibakteriální látky farmakologie MeSH
- bakteriální léková rezistence genetika MeSH
- Campylobacter jejuni * genetika MeSH
- genotyp MeSH
- kampylobakterové infekce * mikrobiologie MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- multilokusová sekvenční typizace MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Autentizace rybích výrobků s využitím analýzy DNA vyžaduje zisk kvalitní DNA bez přítomnosti inhibitorů. V současné době jsou dostupné různé metody pro izolaci nukleových kyselin; pro svou rychlost a nenáročnost extrakčního postupu se staly velmi oblíbenými zejména silikátové centrifugační kolonky. Jejich nevýhodou však může být princip využívající záporný náboj DNA, který může být ovlivněn složením potravin, nebo jejich ucpání v důsledku špatné předúpravy vzorků. Cílem této práce bylo porovnat tři metody izolace DNA využívající různé principy (silikátové centrifugační kolonky, modifikované magnetické kuličky, cetyltrimethylamonium-bromid (CTAB) a chloroformová extrakce) a zhodnotit jejich vhodnost pro izolaci DNA z rybí svaloviny. Posuzovanými kritérii byla výtěžnost, čistota a amplifikovatelnost izolované DNA. Analyzována byla tkáň makrely obecné bez a s přídavkem přídatných látek běžně používaných při výrobě rybích produktů, konkrétně difosforečnanů (E 450) a barviv (E 110 a E 124), a následně byla vybraná metoda aplikována i na komerčně nabízené výrobky z ryb. Jako nejvhodnější se ukázala upravená metoda využívající detergent CTAB.
Authentication of fish products by DNA analysis requires the extraction of high quality DNA without the presence of inhibitors. Many nucleic acid isolation methods are currently available; silicate centrifugal columns have become very popular due to their speed and ease of extraction. However, their disadvantage may be the principle based on DNA charge, which may be affected by food composition, or clogging due to a poor sample pretreatment. The aim of this work was to compare three DNA isolation methods using different principles (silicate centrifugal columns, modified magnetic beads, Cetrimonium bromide and chloroform extraction) and to evaluate their suitability for DNA isolation from fish muscle. The criteria assessed were the recovery, purity and amplifiability of the isolated DNA. Mackerel tissue was analysed without and with the addition of additives commonly used in the manufacture of fish products, namely diphosphates (E 450) and colorants (E 110 and E 124), and the selected method was subsequently applied to commercial fish products. The modified method using the detergent CTAB proved to be the most suitable.
- MeSH
- analýza potravin metody MeSH
- DNA analýza izolace a purifikace MeSH
- lidé MeSH
- polymerázová řetězová reakce MeSH
- potrava z moře (živočišná) analýza MeSH
- potravinářské přísady analýza MeSH
- rybí výrobky * analýza MeSH
- ryby MeSH
- techniky amplifikace nukleových kyselin metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Although Holder pasteurization is the recommended method for processing breast milk, it does affect some of its nutritional and biological properties and is ineffective at inactivating spores. The aim of this study was to find and validate an alternative methodology for processing breast milk to increase its availability for newborn babies and reduce the financial loss associated with discarding milk that has become microbiologically positive. We prepared two series of breast milk samples inoculated with the Bacillus cereus (B. cereus) strain to verify the effectiveness of two high-pressure treatments: (1) 350 MPa/5 min/38 °C in four cycles and (2) cumulative pressure of 350 MPa/20 min/38 °C. We found that the use of pressure in cycles was statistically more effective than cumulative pressure. It reduced the number of spores by three to four orders of magnitude. We verified that the method was reproducible. The routine use of this method could lead to an increased availability of milk for newborn babies, and at the same time, reduce the amount of wasted milk. In addition, high-pressure treatment preserves the nutritional quality of milk.
- Publikační typ
- časopisecké články MeSH
Modern technologies can satisfy human needs only with the use of large quantities of fertilizers and pesticides that are harmful to the environment. For this reason, it is possible to develop new technologies for sustainable agriculture. The process could be carried out by using endophytic microorganisms with a (possible) positive effect on plant vitality. Bacterial endophytes have been reported as plant growth promoters in several kinds of plants under normal and stressful conditions. In this study, isolates of bacterial endophytes from the roots and leaves of Miscanthus giganteus plants were tested for the presence of plant growth-promoting properties and their ability to inhibit pathogens of fungal origin. Selected bacterial isolates were able to solubilize inorganic phosphorus, fix nitrogen, and produce phytohormones, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, and siderophore. Leaf bacterial isolate Pantoea ananat is 50 OL 2 had high production of siderophores (zone ≥ 5 mm), and limited phytohormone production, and was the only one to show ACC deaminase activity. The root bacterial isolate of Pseudomonas libanensis 5 OK 7A showed the best results in phytohormone production (N6-(Δ2-isopentenyl)adenine and indole-3-acetic acid, 11.7 and 12.6 ng·mL-1, respectively). Four fungal cultures-Fusarium sporotrichioides DBM 4330, Sclerotinia sclerotiorum SS-1, Botrytis cinerea DS 90 and Sphaerodes fimicola DS 93-were used to test the antifungal activity of selected bacterial isolates. These fungal cultures represent pathogenic families, especially for crops. All selected root endophyte isolates inhibited the pathogenic growth of all tested fungi with inhibition percentages ranging from 30 to 60%. Antifungal activity was also tested in two forms of immobilization of selected bacterial isolates: one in agar and the other on dextrin-coated cellulose carriers. These results demonstrated that the endophytic Pseudomonas sp. could be used as biofertilizers for crops.
- Publikační typ
- časopisecké články MeSH
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.
- MeSH
- atmosféra MeSH
- Bacteria * genetika MeSH
- houby genetika MeSH
- mikrobiota * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Currently, it is clear that the luxS gene has an impact on the process of biofilm formation in Campylobacter jejuni. However, even within the species, naturally occurring strains of Campylobacter lacking the luxS gene exist, which can form biofilms. In order to better understand the genetic determinants and the role of quorum sensing through the LuxS/AI-2 pathway in biofilm formation, a set of mutant/complemented strains of C. jejuni 81-176 were prepared. Additionally, the impact of the mutagenic strategy used against the luxS gene was investigated. Biofilm formation was affected by both the presence and absence of the luxS gene, and by the mutagenic strategy used. Analysis by CLSM showed that all mutant strains formed significantly less biofilm mass when compared to the wild-type. Interestingly, the deletion mutant (∆luxS) showed a larger decrease in biofilm mass than the substitution (∙luxS) and insertional inactivated ([Formula: see text]luxS) mutants, even though all the mutant strains lost the ability to produce autoinducer-2 molecules. Moreover, the biofilm of the ∆luxS mutant lacked the characteristic microcolonies observed in all other strains. The complementation of all mutant strains resulted in restored ability to produce AI-2, to form a complex biofilm, and to develop microcolonies at the level of the wild-type.
Boswellic acids are biologically active pentacyclic terpenoid compounds derived from Boswellia sp. plants. Extracts containing these acids have a number of positive effects on human health, especially in the treatment of inflammation, arthritis, or asthma. With increasing resistance to common antibiotics, boswellic acid-containing extracts could serve as an alternative or work in synergy with commonly available preparations. This study aims to determine the effect of boswellic acids on suspension cells and biofilms of Staphylococcus epidermidis, Enterococcus faecalis, and Escherichia coli. The antimicrobial and antibiofilm effect found was compared with commonly available antibiotics to control these undesirable microorganisms. The synergistic effect of boswellic acids and common antibiotics on the growth of these microorganisms was also determined. All tested microorganisms showed a positive additive effect of antibiotics and boswellic acid extract. The most significant effect was found in Enterococcus faecalis ATCC 29212 in a combination of 0.2 × MIC80 erythromycin (0.2 mg/L) and 0.8 × MIC80 boswellic acid extract (16 mg/L).
- MeSH
- antibakteriální látky farmakologie MeSH
- biofilmy MeSH
- Boswellia * MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- rostlinné extrakty škodlivé účinky MeSH
- triterpeny * farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- Acanthamoeba fyziologie izolace a purifikace patogenita MeSH
- Campylobacter jejuni * patogenita růst a vývoj MeSH
- interakce hostitele a patogenu MeSH
- kampylobakterové infekce MeSH
- lidé MeSH
- mikrobiální viabilita MeSH
- protozoální infekce MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
