B. Kiziewicz

Magnetic nanoparticles as a drug delivery system that enhance fungicidal activity of polyene antibiotics

This study was designed to assess the antifungal/anti-biofilm and hemolytic properties of two polyene antibiotics, amphotericin B (AMF) and nystatin (NYS), attached to the surface of magnetic nanoparticles (MNP) against clinical isolates of Candida species and human red blood cells, respectively. The developed nanosystems, MNP@AMF and MNP@NYS, displayed stronger fungicidal activity than unbound AMF or NYS. Synergistic activity was observed with a combination of polyenes and MNPs against all tested Candida strains. Nanosystems were more potent than unbound agents when tested against Candida strains in the presence of pus, and as agents able to prevent Candida biofilm formation. The observed inactivation of catalase Cat1 in Candida cells upon treatment with the nanosystems suggests that disruption of the oxidation-reduction balance is a mechanism leading to inhibition of Candida growth. The significant decrease of polyenes lytic activity against host cells after their attachment to MNPs surface indicates improvement in their biocompatibility.

Some Fungi and Water Molds in Waters of Lake Michigan with Emphasis on Those Associated with the Benthic Amphipod Diporeia spp.

To determine types of fungi in the water and associated with the benthic amphipod Diporeia spp., samples were collected at various depths in Lake Michigan in an area where the Diporeia population was in a severe state of decline. No fungi were found associated with living, freshly-dead, or dried Diporeia cultured separately from Lake Michigan water. When dead Diporeia and other organic substrates (snake skin and hemp seeds) were used to grow fungi in Lake Michigan water, a rich and diverse fungal and water mold community was revealed. A total of 31 species were found, with the most common genera being Achlya, Aphanomyces, Myzocytium, and Pythium. In general, species were homogeneously distributed in the water; that is, few differences were found in species richness between nearshore (10–15 m) and offshore (60–80 m) waters, and between near-surface (1 m) and near-bottom waters (1 m off bottom). Sampling occurred during the unstratified period (April and October) to maximize the number of species collected, which may have contributed to the uniform spatial pattern observed. While conclusions must be placed in context with our methods of detection, we found no evidence that a fungal infestation was associated with Diporeia in this region of the lake.

Zoosporic fungi and fungus-like organisms in the Siemianówka dam reservoir

Abstract: The occurrence of fungi in the Siemianowka dam reservoir and in the river Narew downstream and upstream of the reservoir was investigated, during the spring, summer and autumn months, taking into consideration many physicochemical factors of water. Phytoplankton chlorophyll a content was also determined. Eighty-seven fungal species, including 71 fungus-like organisms (Straminipila) and 16 species of true fungi were identified. Most species were found in the river Narew upstream of the reservoir, the fewest inside it. The latter finding can be correlated with cyanobacterial blooming recurring every year. The greatest number of species developed in the spring months, the smallest in the summer period. The surface layer of the reservoir was poorer in species than its deeper layers. Moreover, 6 rare species were detected, including Aphanodictyon apiculatum which is recorded for Poland for the first time.

Water molds Saprolegnia diclina (FLO) isolated from eggs of Carassius carassius L. in Białystok Rivers, Poland

Investigations of occurrence of Saprolegnia diclina from four limnocrenic springs of rivers within the Bialystok where eggs of Carassius carassius were the bait were done. Identification of isolates was accomplished on the basis of their vegetative, asexual reproduction, generative organs and by studying the sequencing of the internal transcribed spacer of nuclear ribosomal DNA (ITS1+5.8S+ITS2). S. diclina occurred in 29 (60.4%) [10(20.1%) in spring, 4 (8.3%) in summer, 11 (23.0%) in autumn and 4 (8.3%) in winter, 2005] of the 48 examined water samples. The results indicate the sequence comparisons of two ITS nuclear DNA for species identification: S. diclina. The results indicate that the sequence of our isolate correspond to S. diclina. It is very important that this study represents the first isolation (on the basis of molecular features) of S. diclina in fresh waters in Poland.

Fungi and fungus-like organisms growing in selected lotic oxbow lakes and tributaries of the Narew River

Abstract Mycological and hydrochemical research was conducted in two different types of reservoirs connected with the Narew riverbed (three tributaries and three lotic oxbow lakes) in two growing seasons. The obtained results seem to indicate that more favorable conditions for the development of the analyzed microorganisms prevailed in the studied tributaries of the Narew. A total of 36 species of fungi and fungus-like organisms were identified in these tributaries in spring and 35 in autumn, while respectively 32 and 26 species in the lotic oxbow lakes. Six taxa not identified in the oxbow lakes were found only in the tributaries of the river. They were: Alternaria alternata, Allomyces moniliformis, Catenaria anguillulae, Leptomitus lacteus, Rhipidium parthenosporum and Saprolegnia diclina. On the other hand, only two species occurred only in the oxbow lakes (not recorded in tributaries) (i.e. Catenophlyctis variabilis and Rhizophlyctis rosea). The differences observed in the microfungi species composition in the studied ecosystems are associated, among others, with the time of the year and physicochemical properties of the water. Hydrochemical parameters such as temperature, pH, Mg, N-NH3, N-NO3, P-PO4 and suspended solids showed positive correlation, and sulfates, chlorides, Ca, Fe correlated negatively with the number of taxa observed.

Aquatic fungi and straminipilous organisms in lakes of the Augustowska Primeval Forest, Poland

We analyzed species composition of aquatic fungi and straminipilous organisms in six lakes located within the Augustowska Primeval Forest, Poland. Mycological observations conducted in the spring and autumn seasons together with hydrochemical analysis in the 2010–2012 revealed the presence of 44 species (10 aquatic fungi and 34 straminipilous organisms). Among the taxa detected, there were some potential pathogens of economically valuable fish species and spawn, including Achlya americana, Ac. polyandra, Saprolegnia ferax and S. parasitica. Some of the species were crustacean pathogens, such as Lagenidium giganteum, Myzocytium microsporum and M. zoophthorum. There were also some common human pathogens Aspergillus niger and Candida tropicalis. Some species, such as Achlya klebsiana, Ac. prolifera, Nowakowskiella elegans, N. macrospora, Pythium debaryanum, Py. inflatum, Rhizophlyctis rosea and Saprolegnia litoralis were common phytosaprobionts.The largest number of species of fungi and straminipilous organisms was identified in Lake Sajenek (22), the fewest in Lake Białe (12).The quantitative composition and qualitative differentiation of mycobiota were influenced by the content of biogenic compounds and the amount of organic substance. The elevated levels of these parameters (Lake Sajenek) stimulated the growth of fungi and straminipilous organisms, whereas very low concentrations of biogenic compounds and a small amount of organic matter (Lake Białe) had an inhibitory effect.Statistical analysis of the results was conducted to determine the correlations between the number of fungal and straminipilous species and the hydrochemical parameters, i.e. water temperature, the level of nitrogen compounds (nitrate nitrogen, ammonium nitrogen), calcium carbohydrate, magnesium carbohydrate, water oxidizability and the content of dry residue, dissolved substances and suspension.

Fungi and Straminipilous organisms found at bathing sites in the vicinity of Białystok

Introduction. Fungi and straminipilous organisms play a significant role in aquatic ecosystems as a food source for many invertebrates and in the process of mineralization of organic matter. Research on the occurrence of fungi and straminipila at bathing sites has a major sanitary and epidemiological significance since it allows registration of fungi that can be potentially pathogenic to man. The ai m of the present study was to establish species diversity of fungi and straminipila found in four bathing sites in the vicinity of Bialystok, to determine or exclude potential etiological factors of mycotic infections, and to determine the effect of physicochemical parameters of the waters examined on the growth of this group of destruents in the spring and autumn of 2006/2007. Material and methods. The baiting method was used to isolate fungi from water samples collected at the respective bathing sites. Fungi and straminipilous organisms were trapped using amphipod crustacean Gammarus pulex , grass snake skin, onion skin, buckwheat seeds, as well as seeds of clover and cannabis. Results. Forty-two species were identified, with the predominance of saprothrophic fungi, particularly species Aspergillus fumigatus - a potential etiologic agent factor for aspergillosis. Most species were found in the water of the bathing site in Supraśl and Jurowce -26 (RF-63.41%), the fewest in Korycin -16 (RF-39.02%). Conclusion. Species diversity of the fungal and straminipilous organisms at the investigated bathing sites depended on characteristics of a given ecosystem, biotic and abiotic factors.