BACKGROUND: Faecal microbiota transplantation (FMT) is a developing therapy for disorders related to gut dysbiosis. Despite its growing application, standardised protocols for FMT filtrate preparation and quality assessment remain undeveloped. The viability of bacteria in the filtrate is crucial for FMT's efficacy and for validating protocol execution. We compared two methods-in vitro cultivation and membrane integrity assessment-for their accuracy, reproducibility and clinical applicability in measuring bacterial viability in frozen FMT stool filtrate. METHODS: Bacterial viability in stool filtrate was evaluated using (i) membrane integrity through fluorescent DNA staining with SYTO9 and propidium iodide, followed by flow cytometry and (ii) culturable bacteria counts (colony-forming units, CFU) under aerobic or anaerobic conditions. RESULTS: Using different types of samples (pure bacterial culture, stool of germ-free and conventionally bred mice, native and heat-treated human stool), we refined the bacterial DNA staining protocol integrated with flow cytometry for assessment of bacterial viability in frozen human stool samples. Both the membrane integrity-based and cultivation-based methods exhibited significant variability in bacterial viability across different FMT filtrates, without correlation. The cultivation-based method showed a mean coefficient of variance of 30.3%, ranging from 7.4% to 60.1%. Conversely, the membrane integrity approach yielded more reproducible results, with a mean coefficient of variance for viable cells of 6.4% ranging from 0.2% to 18.2%. CONCLUSION: Bacterial viability assessment in stool filtrate using the membrane integrity method offers robust and precise data, making it a suitable option for faecal material evaluation in FMT. In contrast, the cultivation-dependent methods produce inconsistent outcomes.

• MeSH
• Bacteria izolace a purifikace   MeSH
• feces * mikrobiologie   MeSH
• fekální transplantace * metody   MeSH
• lidé MeSH
• mikrobiální viabilita * MeSH
• myši MeSH
• průtoková cytometrie * metody   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH

BACKGROUND: Faecal microbiota transplantation (FMT) is an established treatment for Clostridioides difficile infection and is under investigation for other conditions. The availability of suitable donors and the logistics of fresh stool preparation present challenges, making frozen, biobanked stools an attractive alternative. AIMS: This study aimed to evaluate the long-term viability of bacterial populations in faecal samples stored at -80°C for up to 12 months, supporting the feasibility of using frozen grafts for FMT. METHODS: Fifteen faecal samples from nine healthy donors were processed, mixed with cryoprotectants and stored at -80°C. Samples were assessed at baseline and after 3, 6 and 12 months using quantitative culturing methods to determine the concentration of live bacteria. RESULTS: Quantitative analysis showed no significant decrease in bacterial viability over the 12-month period for both aerobic and anaerobic cultures (p = 0.09). At all timepoints, the coefficients of variability in colony-forming unit (CFU) counts were greater between samples (102 ± 21% and 100 ± 13% for aerobic and anaerobic cultures, respectively) than the variability between measurements of the same sample (30 ± 22% and 30 ± 19%). CONCLUSIONS: The study confirmed that faecal microbiota can be preserved with high viability in deep-freeze storage for up to a year, making allogenic FMT from biobanked samples a viable and safer option for patients. However, a multidonor approach may be beneficial to mitigate the risk of viability loss in any single donor sample.

• MeSH
• feces * mikrobiologie   MeSH
• fekální transplantace * metody   MeSH
• kryoprezervace metody   MeSH
• lidé MeSH
• mikrobiální viabilita * MeSH
• zmrazování MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Multidrug resistant (MDR) bacteria are recognized to be one of the most important problems in public health. The outer membrane permeability is a critical intrinsic mechanism of bacterial resistance. In addition, bacteria produce a small number of dormant persister cells causing multidrug tolerance that reduces antimicrobial efficacy. This study aimed to evaluate the inhibitory effects of the combination of aromatic isothiocyanates (ITCs) with membrane-active agents on bacterial persisters and MDR Gram-negative bacteria. Our study demonstrated that membrane-active agents, particularly ethylenediaminetetraacetic acid (EDTA) synergistically enhanced the inhibitory activity of aromatic benzyl ITC and phenethyl ITC against most Gram-negative bacteria strains with fractional inhibitory concentration index values ranging from 0.18 to 0.5 and 0.16 to 0.5, respectively, and contributed to an 8- to 64-fold minimal inhibitory concentration reduction compared with those of aromatic ITCs alone. The EDTA-aromatic ITCs combination effectively reduced the survival rates of tested bacteria and significantly eradicated bacterial persisters (p = 0.033 and 0.037, respectively). The growth kinetics analysis also supported the enhanced inhibitory effect of EDTA-aromatic ITCs combination against tested bacteria. Our results suggested an alternate treatment strategy against Gram-negative bacteria, promoting the entry of aromatic ITCs into bacterial cytoplasm to facilitate bacterial clearance and thus preventing the development of bacterial resistance.

• MeSH
• antibakteriální látky * farmakologie   MeSH
• EDTA * farmakologie   MeSH
• gramnegativní bakterie * účinky léků   MeSH
• isothiokyanatany * farmakologie   MeSH
• mikrobiální testy citlivosti * MeSH
• mikrobiální viabilita účinky léků   MeSH
• mnohočetná bakteriální léková rezistence * účinky léků   MeSH
• permeabilita buněčné membrány účinky léků   MeSH
• synergismus léků MeSH
• vnější bakteriální membrána účinky léků   MeSH
• Publikační typ
• časopisecké články MeSH

Background: Hydatidosis is a deadly parasitic disease that affects both humans and animals. It has received much attention due to widespread health and economic concerns. Materials and Methods: Thirty-three hydatid cysts from the slaughterhouse and butcher shops were analyzed, 17 from the lung and 16 from the liver. The specimens were collected from hydatid fluid and grown on nutritional agar and MacConkey agar using a sterile loop. A Vitek- 2 compact instrument was used to identify bacteria. The viability of the protoscoleces was also determined in these hydatid cysts. Results: The secondary infection rate with bacteria in hepatic and pulmonary hydatid cysts was 24 (72.7%) from a total of thirty-three samples. Several types of bacteria have been isolated from hepatic and pulmonary hydatid cysts. Aeromonas hydrophila had the highest infection rate in hepatic and pulmonary hydatid cysts reaching 20.83% while the lowest infection rate was 4.17% for Leuconostoc mesenteriodes, Lactococcus garvieae, Staphylococcus sciuri, and Staphylococcus hominis, Streptococcus uberis, Pseudomonas stutzer and Vibro vulnificus. Staphylococcus lentus and Lactococcus garvieae had the highest effect on the viability of protoscoleces in liver and lung, reaching 0%, and 13% respectively. Eleven of a total of 13 types of bacteria isolated from hydatid cysts in the liver and lung: were diagnosed for the first time and had not previously been recognized by earlier investigation. The rates of bacterial infection in hepatic and pulmonary hydatid cysts were 76.47% and 68.75%, respectively. Conclusion: The results of our current study indicate that the secondary infection rate with bacteria in hepatic and pulmonary hydatid cysts reached (72.7%), and different types of bacteria in hepatic and pulmonary hydatid cysts have a clear effect on the viability of protoscoleces.

• Klíčová slova
• protoskolex,
• MeSH
• Bacteria izolace a purifikace   klasifikace   patogenita   MeSH
• bakteriální infekce * mikrobiologie   parazitologie   patologie   MeSH
• Echinococcus mikrobiologie   růst a vývoj   MeSH
• echinokokóza mikrobiologie   MeSH
• klinické laboratorní techniky metody   přístrojové vybavení   MeSH
• mikrobiální viabilita MeSH
• ovce * mikrobiologie   parazitologie   MeSH
• statistika jako téma MeSH
• Publikační typ
• klinická studie 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

Mycobacterium avium subsp. paratuberculosis (MAP) is a pathogenic bacterium causing the paratuberculosis, chronic and infectious disease common particularly in wild and domestic ruminants. Currently, culture techniques to detect viable MAP are still used most commonly, although these require a long incubation period. Consequently, a faster molecular method for assessing MAP cell viability based on cell membrane integrity was introduced consisting of sample treatment with the intercalation dye propidium monoazide (PMA) followed by quantitative PCR (qPCR). However, the PMA-qPCR assay is complicated by demanding procedures involving work in a darkroom and on ice. In this study, we therefore optimized a viability assay combining sample treatment with palladium (Pd) compounds as an alternative viability marker to PMA, which does not require such laborious procedures, with subsequent qPCR. The optimized Pd-qPCR conditions consisting of 90 min exposure to 30 μM bis(benzonitrile)dichloropalladium(II) or 30 μM palladium(II)acetate at 5 °C and using ultrapure water as a resuspension medium resulted in differences in quantification cycle (Cq) values between treated live and dead MAP cells of 8.5 and 7.9, respectively, corresponding to approximately 2.5 log units. In addition, Pd-qPCR proved to be superior to PMA-qPCR in distinguishing between live and dead MAP cells. The Pd-qPCR viability assay thus has the potential to replace time-consuming culture methods and demanding PMA-qPCR in the detection and quantification of viable MAP cells with possible application in food, feed, clinical and environmental samples.

• MeSH
• azidy farmakologie   MeSH
• biotest MeSH
• kvantitativní polymerázová řetězová reakce metody   MeSH
• mikrobiální viabilita MeSH
• Mycobacterium avium subsp. paratuberculosis * genetika   MeSH
• palladium farmakologie   MeSH
• paratuberkulóza * mikrobiologie   MeSH
• propidium farmakologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Antigen testing for SARS-CoV-2 (AGT) is generally considered inferior to RT-PCR testing in terms of sensitivity. However, little is known about the infectiousness of RT-PCR positive patients who pass undetected by AGT. In a screening setting for mildly symptomatic or asymptomatic patients with high COVID-19 prevalence (30-40%), 1141 patients were tested using one of five AGTs and RT-PCR. Where the results differed, virus viability in the samples was tested on cell culture (CV-1 cells). The test battery included AGTs by JOYSBIO, Assure Tech, SD Biosensor, VivaChek Biotech and NDFOS. Sensitivities of the ATGs compared to RT-PCR ranged from 42% to 76%. The best test yielded a 76% sensitivity, 97% specificity, 92% positive, and 89% negative predictive values, respectively. However, in the best performing ATG tests, almost 90% of samples with "false negative" AGT results contained no viable virus. Corrected on the virus viability, sensitivities grew to 81-97% and, with one exception, the tests yielded high specificities >96%. Performance characteristics of the best test after adjustment were 96% sensitivity, 97% specificity, 92% positive, and 99% negative predictive values (high prevalence population). We, therefore, believe that virus viability should be considered when assessing the AGT performance. Also, our results indicate that a well-performing antigen test could in a high-prevalence setting serve as an excellent tool for identifying patients shedding viable virus. We also propose that the high proportion of RT-PCR-positive samples containing no viable virus in the group of "false negatives" of the antigen test should be further investigated with the aim of possibly preventing needless isolation of such patients.

• MeSH
• antigeny virové analýza   MeSH
• COVID-19 diagnóza   imunologie   MeSH
• dospělí MeSH
• falešně negativní reakce MeSH
• lidé středního věku MeSH
• lidé MeSH
• mikrobiální viabilita * MeSH
• plošný screening MeSH
• SARS-CoV-2 imunologie   MeSH
• senzitivita a specificita MeSH
• sérologické testy metody   MeSH
• testování na COVID-19 průkazem nukleové kyseliny MeSH
• testování na COVID-19 metody   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Garlic is a well-known example of natural self-defence system consisting of an inactive substrate (alliin) and enzyme (alliinase) which, when combined, produce highly antimicrobial allicin. Increase of alliinase stability and its activity are of paramount importance in various applications relying on its use for in-situ synthesis of allicin or its analogues, e.g., pulmonary drug delivery, treatment of superficial injuries, or urease inhibitors in fertilizers. Here, we discuss the effect of temperature, pH, buffers, salts, and additives, i.e. antioxidants, chelating agents, reducing agents and cosolvents, on the stability and the activity of alliinase extracted from garlic. The effects of the storage temperature and relative humidity on the stability of lyophilized alliinase was demonstrated. A combination of the short half-life, high reactivity and non-specificity to particular proteins are reasons most bacteria cannot deal with allicin's mode of action and develop effective defence mechanism, which could be the key to sustainable drug design addressing serious problems with escalating emergence of multidrug-resistant (MDR) bacterial strains.

• MeSH
• antibakteriální látky farmakologie   MeSH
• Bacteria účinky léků   ultrastruktura   MeSH
• biokatalýza účinky léků   MeSH
• časové faktory MeSH
• česnek enzymologie   MeSH
• chemické jevy * MeSH
• disulfidy chemie   metabolismus   MeSH
• kinetika MeSH
• koncentrace vodíkových iontů MeSH
• kyseliny sulfinové chemie   metabolismus   MeSH
• lyasy štěpící vazby C-S metabolismus   MeSH
• lyofilizace MeSH
• mikrobiální testy citlivosti MeSH
• mikrobiální viabilita účinky léků   MeSH
• pufry MeSH
• stabilita enzymů účinky léků   MeSH
• stereoizomerie MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The plasma-activated gas is capable of decontaminating surfaces of different materials in remote distances. The effect of plasma-activated water vapor on Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli biofilm contamination was investigated on the polypropylene nonwoven textile surface. The robust and technically simple multi-hollow surface dielectric barrier discharge was used as a low-temperature atmospheric plasma source to activate the water-based medium. The germicidal efficiency of short and long-time exposure to plasma-activated water vapor was evaluated by standard microbiological cultivation and fluorescence analysis using a fluorescence multiwell plate reader. The test was repeated in different distances of the contaminated polypropylene nonwoven sample from the surface of the plasma source. The detection of reactive species in plasma-activated gas flow and condensed activated vapor, and thermal and electrical properties of the used plasma source, were measured. The bacterial biofilm decontamination efficiency increased with the exposure time and the plasma source power input. The log reduction of viable biofilm units decreased with the increasing distance from the dielectric surface.

• MeSH
• biofilmy účinky léků   MeSH
• dekontaminace metody   MeSH
• elektřina * MeSH
• Escherichia coli účinky léků   MeSH
• methicilin rezistentní Staphylococcus aureus účinky léků   MeSH
• mikrobiální viabilita MeSH
• plazmové plyny farmakologie   MeSH
• Pseudomonas aeruginosa účinky léků   MeSH
• Staphylococcus epidermidis účinky léků   MeSH
• Publikační typ
• časopisecké články MeSH

Alterations in brain functioning, especially in regions associated with cognition, can result from infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and are predicted to result in various psychiatric diseases. Recent studies have shown that SARS-CoV-2 infection and coronavirus disease 2019 (COVID-19) can directly or indirectly affect the central nervous system (CNS). Therefore, diseases associated with sequelae of COVID-19, or 'long COVID', also include serious long-term mental and cognitive changes, including the condition recently termed 'brain fog'. Hypoxia in the microenvironment of select brain areas may benefit the reproductive capacity of the virus. It is possible that in areas of cerebral hypoxia, neuronal cell energy metabolism may become compromised after integration of the viral genome, resulting in mitochondrial dysfunction. Because of their need for constant high metabolism, cerebral tissues require an immediate and constant supply of oxygen. In hypoxic conditions, neurons with the highest oxygen demand become dysfunctional. The resulting cognitive impairment benefits viral spread, as infected individuals exhibit behaviors that reduce protection against infection. The effects of compromised mitochondrial function may also be an evolutionary advantage for SARS-CoV-2 in terms of host interaction. A high viral load in patients with COVID-19 that involves the CNS results in the compromise of neurons with high-level energy metabolism. Therefore, we propose that selective neuronal mitochondrial targeting in SARS-CoV-2 infection affects cognitive processes to induce 'brain fog' and results in behavioral changes that favor viral propagation. Cognitive changes associated with COVID-19 will have increasing significance for patient diagnosis, prognosis, and long-term care.

• MeSH
• COVID-19 komplikace   metabolismus   patofyziologie   psychologie   přenos   MeSH
• energetický metabolismus MeSH
• kognitivní dysfunkce metabolismus   patofyziologie   psychologie   MeSH
• lidé MeSH
• mikrobiální viabilita MeSH
• mitochondrie metabolismus   MeSH
• mozková hypoxie metabolismus   patofyziologie   psychologie   MeSH
• neurony metabolismus   MeSH
• replikace viru MeSH
• SARS-CoV-2 fyziologie   MeSH
• virová nálož MeSH
• zdravé chování * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• úvodníky MeSH