1. Loop-mediated isothermal amplification of specific endoglucanase gene sequence for detection of the bacterial wilt pathogen Ralstonia solanacearumRok Lenarčič, Dany Morisset, Manca Pirc, Pablo Llop, Maja Ravnikar, Tanja Dreo, 2014, original scientific article Abstract: The increased globalization of crops production and processing industries also promotes the side-effects of more rapid and efficient spread of plant pathogens. To prevent the associated economic losses, and particularly those related to bacterial diseases where their management relies on removal of the infected material from production, simple, easy-to-perform, rapid and cost-effective tests are needed. Loop-mediated isothermal amplification (LAMP) assays that target 16S rRNA, fliC and egl genes were compared and evaluated as on-site applications. The assay with the best performance was that targeted to the egl gene, which shows high analytical specificity for diverse strains of the betaproteobacterium Ralstonia solanacearum, including its non-European and non-race 3 biovar 2 strains. The additional melting curve analysis provides confirmation of the test results. According to our extensive assessment, the egl LAMP assay requires minimum sample preparation (a few minutes of boiling) for the identification of pure cultures and ooze from symptomatic material, and it can also be used in a high-throughput format in the laboratory. This provides sensitive and reliable detection of R. solanacearum strains of different phylotypes. Keywords: plant pathogens, bacterial diseases Published in DiRROS: 02.08.2024; Views: 116; Downloads: 65
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2. Assessment of different experimental setups to determineviral filtration efficiency of face masksArijana Filipić, Katja Fric, Maja Ravnikar, Polona Kogovšek, 2022, original scientific article Abstract: Abstract
As a result of the COVID-19 pandemic, many new materials and masks came onto the market. To determine their suitability, several standards specify which properties to test, including bacterial filtration efficiency (BFE), while none describe how to determine viral filtration efficiency (VFE), a property that is particularly important in times of pandemic. Therefore, we focused our research on evaluating the suitability and efficiency of different systems for determining VFE. Here, we evaluated the VFE of 6 mask types (e.g., a surgical mask, a respirator, material for mask production, and cloth masks) with different filtration efficiencies in four experimental setups and compared the results with BFE results. The study included 17 BFE and 22 VFE experiments with 73 and 81 mask samples tested, respectively. We have shown that the masks tested had high VFE (>99% for surgical masks and respirators, ≥98% for material, and 87–97% for cloth masks) and that all experimental setups provided highly reproducible and reliable VFE results (coefficient of variation < 6%). Therefore, the VFE tests described in this study can be integrated into existing standards for mask testing. Keywords: face masks, virus filtration efficiency, bacterial filtration efficiency, EN 14683:2019+AC:2019, air sampler Published in DiRROS: 17.07.2024; Views: 125; Downloads: 85
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3. Subchronic exposure of rats to sublethal dose of microcystin-YR induces DNA damage in multiple organsMetka Filipič, Bojana Žegura, Bojan Sedmak, Irena Horvat-Žnidaršič, Aleksandra Milutinović Živin, Dušan Šuput, 2007, original scientific article Abstract: Background. Microcystins (MCs) are cyclic heptapeptides that are considered tobe liver specific toxins. They are potent tumour promoters and recent studies indicate that they are also genotoxic. In this study we measured DNA damage in lymphocytes, liver, kidney (cortex and medulla), lung, spleen and brain cells of male Fisher F344 rats that were exposed to sublethal dose (every second day 10 Ugžkg b.w.č i.p) of microeysrin-YR (MCYR) for one month. Methods. At the end of exposure the animals were sacrificed, the lymphocytes were isolated from blood taken from jugular vein, liver cells were obtained byperfusion with collagenase A and the cells from other organs were isolated by incubating small tissue pieces with eollagenase A. The DNA damage in isolated cells was measured with the single cells gel electrophoresis (SCGE) also called the comet assay. Results. A significant increase of the % tail DNAin MCYR-exposed animals compared to the nonexposed control ones was observed in brain (2.5 fold), liver (2.1 fold), kidney medulla (1.9 fold), kidney cortex (1.8 fold) and lung (1.7 fold) cells, while the DNA from lymphocytes and spleen cells was not affected. Conclusion. This study demonstrated that subehronic exposure to sublethal doses of MCs can induce systemicgenotoxicity in mammals, and it affects not only the liver but also other vital organs. Keywords: DNA damage, comet assay, cyanobacteria, bacterial toxins, rats, inbred F344 Published in DiRROS: 20.02.2024; Views: 366; Downloads: 84
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4. Effect of sucrose concentration on streptococcus mutans adhesion to dental material surfacesAnamarija Zore, Franc Rojko, Nives Matijaković Mlinarić, Jona Veber, Aleksander Učakar, Roman Štukelj, Andreja Pondelak, Andrijana Sever Škapin, Klemen Bohinc, 2024, original scientific article Abstract: Enamel demineralization, known as dental caries, is instigated by the bacterium Streptococcus mutans, which generates acid during carbohydrate metabolism. Among carbohydrates, sucrose is the most cariogenic and capable of biofilm formation. This study aimed to explore and comprehend Streptococcus mutans’ adherence to two prevalent dental material surfaces, i.e., a cobalt–chromium(Co-Cr) alloy and a resin-based composite, under the influence of various sucrose concentrations. To understand bacterial adhesion, the surfaces were characterized using profilometry, tensiometry, and surface charge measurements. Bacterial adhesion was evaluated using scanning electron microscopy and crystal violet dye methods. Results revealed that the composite surface exhibited greater rough-ness compared with the Co-Cr alloy surface. Both surfaces displayed hydrophilic properties and a negative surface charge. Bacterial adhesion experiments indicated lower bacterial adherence to the Co-Cr alloy than to the composite surface before the addition of sucrose. However, the introduction of sucrose resulted in biofilm development on both surfaces, showcasing a similar increase in bacterial adhesion, with the highest levels being observed at a 5% sucrose concentration in the bacterial suspension. In conclusion, the findings suggest sucrose-rich foods could facilitate bacterial adaptation despite less favorable surface characteristics, thereby promoting biofilm formation. Keywords: bacterial adhesion, streptococcus mutans, dental material surfaces, sucrose concentration Published in DiRROS: 31.01.2024; Views: 399; Downloads: 170
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5. Antibacterial effect of polymethyl methacrylate resin base containing TiO2 nanoparticlesAnamarija Zore, Anže Abram, Aleksander Učakar, Ivo Godina, Franc Rojko, Roman Štukelj, Andrijana Sever Škapin, Rajko Vidrih, Olivera Dolić, Valentina Veselinović, Klemen Bohinc, 2022, original scientific article Abstract: Restorations in dentistry must reproduce the aspect of the patient’s natural teeth and require non-toxicity, biocompatibility, and good mechanical properties in order to last longer. Restorations are permanently in contact with microbes that can adhere to and form biofilms. The purpose of this study was to determine the adhesion extent of Streptococcus mutans to polymethyl methacrylate (PMMA) resin base containing TiO2 nanoparticles. To understand the adhesion of Streptococcus mutans on the modified resin-based surfaces, the following surface properties were measured: the roughness, contact angle, zeta potential and CIE color parameters. Evaluation of tensile stress performance in TiO2 modified PMMA showed that the maximum tensile stress of the modified PMMA resin decreases with an increasing amount of TiO2 nanoparticles. The increasing amount of TiO2 decreases the roughness and causes contact angles in the border between hydrophilic and hydrophobic surfaces. All the studied surfaces are negatively charged and added TiO2 tends to increase the zeta potential. The addition of TiO2 nanoparticles increases the lightness and decreases the intensity of the red and yellow color. The increasing addition of TiO2 nanoparticles into PMMA increases the morphological change of bacterial cells. Keywords: bacterial adhesion, Streptococcus mutans, polymethyl methacrylate resin, TiO2, surface properties Published in DiRROS: 20.12.2023; Views: 357; Downloads: 191
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6. Biophysical properties of foamed and solid polymers used in orthotics and prostheticsKlemen Bohinc, Anže Abram, Anamarija Zore, Roman Štukelj, Ana Lenarčič, Rajko Vidrih, Andrijana Sever Škapin, 2021, original scientific article Abstract: Orthotic and prosthetic materials should have good mechanical and antibacterial properties. Therefore, in our study, we consider four common foamed closed-cells and two solid polymeric materials regarding their mechanical behaviour and tendency for bacterial adhesion. For all materials, the surface roughness, hydrophobicity, zeta potential, tensile properties, hardness and CIE color parameters were measured. We found that foamed polymeric materials have higher roughness, higher hydrophobicity, lower Young's modulus, lower maximum tensile strength and lower hardness than solid materials. Bacterial adhesion test measurements based on observation by scanning electron microscopy show much a lower adhesion extent of S. aureus on solid materials than on foamed materials. The measured biophysical properties could be the key data for users to select the optimal materials. Keywords: surface characterization, bacterial adhesion, foamed materials, prosthetic and orthotic material, surfaces Published in DiRROS: 22.05.2023; Views: 439; Downloads: 316
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7. The effects of topical antibiotics on eradication and acquisition of third-generation cephalosporin and carbapenem-resistant Gram-negative bacteria in ICU patients : ǂa ǂpost hoc analysis from a multicentre cluster-randomized trialNienke L. Plantinga, Bastiaan H. Wittekamp, Christian Brun-Buisson, Marc J. M. Bonten, 2020, original scientific article Abstract: Objectives: The aim was to quantify the effects of selective digestive tract decontamination (SDD) consisting of a mouth paste and gastro-enteral suspension, selective oropharyngeal decontamination with a mouth paste (SOD) and 1-2% chlorhexidine (CHX) mouthwash on eradication and acquisition of carriage of third-generation cephalosporin-resistant Enterobacterales (3GCR-E) and carbapenem-resistant Gram-negative bacteria (CR-GNB) in Intensive Care Unit (ICU) patients. Methods: This was a nested cohort study within a cluster-randomized cross-over trial in six European countries and 13 ICUs with 8665 patients. Eradication and acquisition during ICU stay of 3GCR-E and CRGNB were investigated separately in the rectum and respiratory tract for the three interventions and compared with standard care (SC) using Cox-regression competing events analyses. Results: Adjusted cause specific hazard ratios (CSHR) for eradication of rectal carriage for SDD were 1.76 (95% CI 1.31-2.36) for 3GCR-E and 3.17 (95% CI 1.60-6.29) for CR-GNB compared with SC. For the respiratory tract, adjusted CSHR for eradication of 3GCR-E were 1.47 (0.98-2.20) for SDD and 1.38 (0.92-2.06) for SOD compared with SC, and for eradication of CR-GNB these were 0.77 (0.41-1.45) for SDD and 0.81 (0.44-1.51) for SOD, compared with SC. Adjusted CSHRs for acquisition of rectal carriage during SDD (compared with SC) were 0.51 (0.40-0.64) for 3GCR-E and of 0.56 (0.40-0.78) for CR-GNB. Adjusted CSHRs for acquiring respiratory tract carriage with 3GCR-E compared with SC were 0.38 (0.28-0.50) for SDD and 0.55 (0.42-0.71) for SOD, and for CR-GNB 0.46 (0.33-0.64) during SDD and 0.60 (0.44-0.81) during SOD, respectively. SOD was not associated with eradication or acquisition of 3GCR-E and CR-GNB in the rectum. Conclusions: Among mechanically ventilated ICU patients, SDD was associated with more eradication and less acquisition of 3GCR-E and CR-GNB in the rectum than SC. SDD and SOD were associated with less acquisition of both 3GCR-E and CR-GNB than SC in the respiratory tract. Keywords: intensive care units -- analysis -- epidemiology, bacterial drug resistance, anti-infective agents -- therapeutic use decontamination, beta-lactamases, Gram-negative bacteria, gastrointestinal tract -- microbiology -- drug therapy, cohort studies, colonization, ESBL, digestive tract Published in DiRROS: 27.05.2022; Views: 713; Downloads: 276
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8. Decontamination strategies and bloodstream infections with antibiotic-resistant microorganisms in ventilated patients : a randomized clinical trialBastiaan H. Wittekamp, Nienke L. Plantinga, Ben S. Cooper, Joaquin Lopez-Contreras, Pere Coll, Jordi Mancebo, Matt P. Wise, Matt P. G. Morgan, Pieter Depuydt, Jerina Boelens, Viktorija Tomič, Franc Šifrer, 2018, original scientific article Abstract: Importance: The effects of chlorhexidine (CHX) mouthwash, selective oropharyngeal decontamination (SOD), and selective digestive tract decontamination (SDD) on patient outcomes in ICUs with moderate to high levels of antibiotic resistance are unknown. Objective: To determine associations between CHX 2%, SOD, and SDD and the occurrence of ICU-acquired bloodstream infections with multidrug-resistant gram-negative bacteria (MDRGNB) and 28-day mortality in ICUs with moderate to high levels of antibiotic resistance. Design, setting, and participants: Randomized trial conducted from December 1, 2013, to May 31, 2017, in 13 European ICUs where at least 5% of bloodstream infections are caused by extended-spectrum [beta]-lactamase-producing Enterobacteriaceae. Patients with anticipated mechanical ventilation of more than 24 hours were eligible. The final date of follow-up was September 20, 2017. Interventions: Standard care was daily CHX 2% body washings and a hand hygiene improvement program. Following a baseline period from 6 to 14 months, each ICU was assigned in random order to 3 separate 6-month intervention periods with either CHX 2% mouthwash, SOD (mouthpaste with colistin, tobramycin, and nystatin), or SDD (the same mouthpaste and gastrointestinal suspension with the same antibiotics), all applied 4 times daily. Main outcomes and measures: The occurrence of ICU-acquired bloodstream infection with MDRGNB (primary outcome) and 28-day mortality (secondary outcome) during each intervention period compared with the baseline period. Results: A total of 8665 patients (median age, 64.1 years; 5561 men [64.2%]) were included in the study (2251, 2108, 2224, and 2082 in the baseline, CHX, SOD, and SDD periods, respectively). ICU-acquired bloodstream infection with MDRGNB occurred among 144 patients (154 episodes) in 2.1%, 1.8%, 1.5%, and 1.2% of included patients during the baseline, CHX, SOD, and SDD periods, respectively. Absolute risk reductions were 0.3% (95% CI, -0.6% to 1.1%), 0.6% (95% CI, -0.2% to 1.4%), and 0.8% (95% CI, 0.1% to 1.6%) for CHX, SOD, and SDD, respectively, compared with baseline. Adjusted hazard ratios were 1.13 (95% CI, 0.68-1.88), 0.89 (95% CI, 0.55-1.45), and 0.70 (95% CI, 0.43-1.14) during the CHX, SOD, and SDD periods, respectively, vs baseline. Crude mortality risks on day 28 were 31.9%, 32.9%, 32.4%, and 34.1% during the baseline, CHX, SOD, and SDD periods, respectively. Adjusted odds ratios for 28-day mortality were 1.07 (95% CI, 0.86-1.32), 1.05 (95% CI, 0.85-1.29), and 1.03 (95% CI, 0.80-1.32) for CHX, SOD, and SDD, respectively, vs baseline. Conclusions and relevance: Among patients receiving mechanical ventilation in ICUs with moderate to high antibiotic resistance prevalence, use of CHX mouthwash, SOD, or SDD was not associated with reductions in ICU-acquired bloodstream infections caused by MDRGNB compared with standard care. Keywords: anti-infective agents -- therapeutic use, bacteremia -- prevention and control, chlorhexidine -- therapeutic use, cross infection -- prevention and control, disinfection -- methods, bacterial drug resistance, gastrointestinal tract -- microbiology, Gram-negative bacterial infections -- prevention and control, hospital mortality, intensive care units, mouthwashes -- therapeutic use, oropharynx -- microbiology, artificial respiration, multicenter study, randomized controlled trial Published in DiRROS: 09.11.2020; Views: 1395; Downloads: 490
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9. An EAACI position paper on the investigation of perioperative immediate hypersensitivity reactionsLene Heise Garvey, Didier G. Ebo, Paul Michel Mertes, Pascale Dewachter, Tomaz Garcez, Peter Kopač, Jose Julio Laguna, Anca Chiriac, Ingrid Terreehorst, Susanna Voltolini, K Scherer, 2019, review article Abstract: Perioperative immediate hypersensitivity reactions are rare. Subsequent allergy investigation is complicated by multiple simultaneous drug exposures, the use of drugs with potent effects and the many differential diagnoses to hypersensitivity in the perioperative setting. The approach to the investigation of these complex reactions is not standardized and it is becoming increasingly apparent that collaboration between experts in the field of allergy/immunology/dermatology and anaesthesiology is needed to provide the best possible care for these patients. The EAACI task force behind this position paper has therefore combined the expertise of allergists, immunologists and anaesthesiologists. The aims of this position paper are to provide recommendations for the investigation of immediate type perioperative hypersensitivity reactions and to provide practical information that can assist clinicians in planning and carrying out investigations. Keywords: allergy and immunology -- diagnosis, drug hypersensitivity -- diagnosis, anaphylaxis, anesthesia, anesthetics, opioid analgesics, anti-bacterial agents, anti-inflammatory agents, non-steroidal opioids, antibiotics Published in DiRROS: 16.10.2020; Views: 1721; Downloads: 453
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10. Comparative epidemiology of suspected perioperative hypersensitivity reactionsPaul Michel Mertes, Didier G. Ebo, Tomaz Garcez, Michael Rose, Vito Sabato, Tomonori Takazawa, Peter J. Cooke, Russel C. Clarke, Pascale Dewachter, Lene Heise Garvey, Anne Berit Guttormsen, David L. Hepner, Philip M. Hopkins, David A. Khan, Peter Kopač, Peter R. Platt, Louise C. Savic, 2019, review article Abstract: Suspected perioperative hypersensitivity reactions are rare but contribute significantly to the morbidity and mortality of surgical procedures. Recent publications have highlighted the differences between countries concerning the respective risk of different drugs, and changes in patterns of causal agents and the emergence of new allergens. This review summarises recent information on the epidemiology of perioperative hypersensitivity reactions, with specific consideration of differences between geographic areas for the most frequently involved offending agents. Keywords: anaphylaxis, anti-bacterial agents, blood, chlorhexidine, latex, neuromuscular blocking agents, hypersensitivity, drug hypersensitivity, sugammadex, antibiotics, blood products, perioperative anaphylaxis, perioperative hypersensitivity Published in DiRROS: 16.10.2020; Views: 1612; Downloads: 447
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