Redescription of Diastolaimus grossus (Truskova & Eroshenko, 1977) Andrássy, 1984 (Rhabditida, Chambersiellidae) from Europe and comments on its phylogenetic position.

Two populations of the species Diastolaimus grossus have been obtained from bark of trees in Bosnia and Herzegovina and the Czech Republic. The species is described and characterized in detail using morphological techniques (light and electron scanning microscopy) and morphometrical (Gower General Similarity coefficient of morphological characters) and molecular analyses, including phylogenetic analysis of all related and already sequenced species of the family Chambersiellidae. Morphological and molecular analyses, based on 18S and 28S ribosomal DNA sequences, show that the family Chambersiellidae is polyphyletic, being the subfamily Chambersiellinae related with Cephalobomorpha and Tylenchomorpha, and the subfamily Macrolaiminae is located into Panagrolaimomorpha. The genus Diastolaimus, previously belonging to Macrolaiminae, is transferred to Chambersiellinae. Diastolaimus mexicanus is proposed as a junior synonym of D. grossus.

Do foodborne polyethylene microparticles affect the health of rainbow trout (Oncorhynchus mykiss)?

Due to the fact that plastic pollution is a global environmental problem of modern age, studies on the impact of these synthetic materials on aquatic, and especially fish organisms, are an important part of the ecosystem and human nutrition. In our study, the toxicity of pristine polyethylene (PE) microparticles (approx. 50 µm) on rainbow trout (Oncorhynchus mykiss) was tested in three different dietary concentrations - 0.5%, 2% and 5%. After six weeks of exposure, various health indices were evaluated. Electron microscopy of the intestine revealed the disintegration of PE particles to <5 µm in size, and thus we concluded that microplastics are able to reach tissues. The haematological profile revealed changes in total red blood cells count and haematocrit (5% PE) which could be associated with spleen congestion observed histologically. The marker of lipid peroxidation was increased in gills suggesting the disruption of balance in antioxidant enzymes capacity and histopathological imaging revealed inflammation in higher PE concentrations. In addition, ammonia was decreased and calcium elevated in biochemical profile, confirming the gill damage. Electron microscopy of the gills showed lesions of lamellae and visible rings around the mucinous cell opening indicating their higher activity. Another injured was the liver tissue, as confirmed by hepatodystrophies and increased expression of pro-inflammatory genes in 2% PE. Impaired innate immunity was confirmed by an increased presence of mucinous cells and a decrease in leukocytes. Kidney damage manifested itself by higher expression of pro-inflammatory cytokines and histopathology. The damage in gills, liver and kidney together correlated with the increased antioxidant capacity of plasma. In conclusion, PE microparticles are able to affect health indices of O. mykiss. The potential problem for aquatic ecosystems and even human consumption should be considered.

Investigation of Dissolution Behavior HPMC/Eudragit®/Magnesium Aluminometasilicate Oral Matrices Based on NMR Solid-State Spectroscopy and Dynamic Characteristics of Gel Layer.

Burst drug release is often considered a negative phenomenon resulting in unexpected toxicity or tissue irritation. Optimal release of a highly soluble active pharmaceutical ingredient (API) from hypromellose (HPMC) matrices is technologically impossible; therefore, a combination of polymers is required for burst effect reduction. Promising variant could be seen in combination of HPMC and insoluble Eudragits® as water dispersions. These can be applied only on API/insoluble filler mixture as over-wetting prevention. The main hurdle is a limited water absorption capacity (WAC) of filler. Therefore, the object of this study was to investigate the dissolution behavior of levetiracetam from HPMC/Eudragit®NE matrices using magnesium aluminometasilicate (Neusilin® US2) as filler with excellent WAC. Part of this study was also to assess influence of thermal treatment on quality parameters of matrices. The use of Neusilin® allowed the application of Eudragit® dispersion to API/Neusilin® mixture in one step during high-shear wet granulation. HPMC was added extragranularly. Obtained matrices were investigated for qualitative characteristics, NMR solid-state spectroscopy (ssNMR), gel layer dynamic parameters, SEM, and principal component analysis (PCA). Decrease in burst effect (max. of 33.6%) and dissolution rate, increase in fitting to zero-order kinetics, and paradoxical reduction in gel layer thickness were observed with rising Eudragit® NE concentration. The explanation was done by ssNMR, which clearly showed a significant reduction of the API particle size (150-500 nm) in granules as effect of surfactant present in dispersion in dependence on Eudragit®NE amount. This change in API particle size resulted in a significantly larger interface between these two entities. Based on ANOVA and PCA, thermal treatment was not revealed as a useful procedure for this system.

Biological Effects of Drug-Free Alginate Beads Cross-Linked by Copper Ions Prepared Using External Ionotropic Gelation.

External ionotropic gelation offers a unique possibility to entrap multivalent ions in a polymer structure. The aim of this experimental study was to prepare new drug-free sodium alginate (ALG) particles cross-linked by Cu2+ ions and to investigate their technological parameters (particle size, sphericity, surface topology, swelling capacity, copper content, release of Cu2+ ions, mucoadhesivity) and biological activity (cytotoxicity and efficiency against the most common vaginal pathogens-Herpes simplex, Escherichia coli, Candida albicans) with respect to potential vaginal administration. Beads prepared from NaALG dispersions (3 or 4%) were cross-linked by Cu2+ ions (0.5 or 1.0 M CuCl2) using external ionotropic gelation. Prepared mucoadhesive beads with particle size over 1000 µm exhibited sufficient sphericity (all ˃0.89) and copper content (214.8-249.07 g/kg), which increased with concentration of polymer and hardening solution. Dissolution behaviour was characterized by extended burst effect, followed by 2 h of copper release. The efficiency of all samples against the most common vaginal pathogens was observed at cytotoxic Cu2+ concentrations. Anti-HSV activity was demonstrated at a Cu2+ concentration of 546 mg/L. Antibacterial activity of beads (expressed as minimum inhibition concentration, MIC) was influenced mainly by the rate of Cu2+ release which was controlled by the extent of swelling capacity. Lower MIC values were found for E. coli in comparison with C. albicans. Sample ALG-3_1.0 exhibited the fastest copper release and was proved to be the most effective against both bacteria. This could be a result of its lower polymer concentration in combination with smaller particle size and thus larger surface area.

Pseudogymnoascus destructans: evidence of virulent skin invasion for bats under natural conditions, Europe.

While Pseudogymnoascus destructans has been responsible for mass bat mortalities from white-nose syndrome (WNS) in North America, its virulence in Europe has been questioned. To shed the light on the issue of host-pathogen interaction between European bats and P. destructans, we examined seventeen bats emerging from the fungus-positive underground hibernacula in the Czech Republic during early spring 2013. Dual wing-membrane biopsies were taken from Barbastella barbastellus (1), Myotis daubentonii (1), Myotis emarginatus (1), Myotis myotis (11), Myotis nattereri (1) and Plecotus auritus (2) for standard histopathology and transmission electron microscopy. Non-lethal collection of suspected WNS lesions was guided by trans-illumination of the wing membranes with ultraviolet light. All bats selected for the present study were PCR-positive for P. destructans and showed microscopic findings consistent with the histopathological criteria for WNS diagnosis. Ultramicroscopy revealed oedema of the connective tissue and derangement of the fibroblasts and elastic fibres associated with skin invasion by P. destructans. Extensive fungal infection induced a marked inflammatory infiltration by neutrophils at the interface between the damaged part of the wing membrane replaced by the fungus and membrane tissue not yet invaded by the pathogen. There was no sign of keratinolytic activity in the stratum corneum. Here, we show that lesions pathognomonic for WNS are common in European bats and may also include overwhelming full-thickness fungal growth through the wing membrane equal in severity to reports from North America. Inter-continental differences in the outcome of WNS in bats in terms of morbidity/mortality may therefore not be due to differences in the pathogen itself.

Microscopy, culture, and quantitative real-time PCR examination confirm internalization of mycobacteria in plants.

The environment is a reservoir of nontuberculous mycobacteria and is considered a source of infection for animals and humans. Mycobacteria can persist in different types of environments for a relatively long time. We have studied their possible internalization into plant tissue through intact, as well as damaged, root systems of different types of plants grown in vitro and under field conditions. The substrate into which plants were seeded was previously contaminated with different strains of Mycobacterium avium (10(8) to 10(10) cells/g of soil) and feces from animals with paratuberculosis. We detected M. avium subsp. avium, hominissuis, and paratuberculosis in the stems and leaves of the plants by both culture and real-time quantitative PCR. The presence of mycobacteria in the plant tissues was confirmed by microscopy. The concentration of mycobacteria found inside plant tissue was several orders of magnitude lower (up to 10(4) cells/g of tissue) than the initial concentration of mycobacteria present in the culture medium or substrate. These findings led us to the hypothesis that plants may play a role in the spread and transmission of mycobacteria to other organisms in the environment.

Investigation of ornamental fish entering the EU for the presence of ranaviruses.

A survey was performed on ornamental fish imported into the EU to detect viral agents belonging to the genus Ranavirus. The objective was to gain knowledge of the potential for these systemic iridoviruses to gain entry into the EU via international trade in ornamental fish. A total of 208 pooled samples, representing 753 individual fish, were tested. The samples included 13 orders and 37 families, originating from different countries and continents. Tissues from fish that died during or just after transport were collected and examined by standard virological techniques in epithelioma papulosum cyprini cells, by transmission electron microscopy and by PCR for the detection of the major capsid protein and DNA polymerase gene sequences of ranaviruses. Virus was isolated from nine fish species but ranavirus was not identified in those samples. The results suggest that ranaviruses are not highly prevalent in ornamental fish imported into the EU.

Herpesvirus-associated papillomatosis in a green lizard.

Papillomatous skin lesions from a green lizard (Lacerta viridis) were examined histologically, using electron microscopy and DNA was isolated from the lesions for herpes-viral DNA detection. Histology confirmed the lesions to be squamous epithelial papillomas. Using electron microscopy, no virus particles were detected. The specific sequence of herpesviral DNA-directed DNA polymerase (EC 2.7.7.7) was amplified using degenerate primers in a nested format. The 235-base-pair (bp) sequence was sequenced and compared with previously published DNA-directed DNA polymerase sequences from various reptile herpesviruses. The sequence from the green lizard showed significant similarity with sequence of fibropapilloma-associated turtle herpesviruses from sea turtles.

Heavy contamination of operating room air by Penicillium species: identification of the source and attempts at decontamination.

Increased rates of nosocomial infection caused by filamentous fungi in immunocompromised patients prompted microbiologic surveillance of the central air handling systems in our hospital. During a 4-year period, Penicillium species were isolated from 47 patients, including two with surgical wound infections caused by Penicillium. Counts of Penicillium in operating room air were much higher (195 colony-forming units [CFU]/m3) than in 95% filtered corridor air (14.6 CFU/m3; p less than 0.01). Ventilation ducts and terminal units lined with fiberglass in the operating room air handling system were heavily contaminated by Penicillium; the fiberglass was also contaminated with Aspergillus species. Corrective measures included filter replacement and decontamination of the ventilation system with aerosolized chlorine solution. Although operating room air remained free of filamentous fungi during the next 7 months, contamination eventually recurred and required repeated decontamination. We believe that certification guidelines are highly desirable for hospital ventilation systems, especially if the system serves immunocompromised patients.

Effect of frequent guidewire changes on triple-lumen catheter sepsis.

Frequent guidewire changes of single-lumen (SLC) and triple-lumen (TLC) catheters have been proposed to decrease catheter sepsis. We placed TLC in 126 patients needing total parenteral nutrition (TPN) and multiple venous access, prospectively randomizing them to two groups: group I received a guidewire change every 3 days, and group II received guidewire changes for mechanical or septic complications only. Tips were cultured at each line change and tips and blood for each septic episode. Catheter sepsis was defined by the criteria of the Association for Practitioners in Infection Control (APIC). There were 67 positive cultures in 52 patients, but most produced very few colonies or grew the same organisms in other infection sites. Forty-seven% of all cultures grew Staphylococci, and 23% grew Candida. APIC-defined catheter sepsis was detected in 12.7% of group I and 15.9% of group II. Although we observed no statistically significant difference in the two techniques, if we assume that a 20% difference in the incidence of catheter-induced sepsis would be important to detect, the probability of failing to detect such a difference is 0.24 with an 0.05 level of significance (two-sided). Prophylactic guidewire changes did not alter the incidence of catheter sepsis in patients with TLC who required TPN. The high rate of sepsis and Candida infection may be due to the critical illness of the immunocompromised population studied.