Rok Kostanjsek

• prof. dr.
• Professor (Full) at University of Ljubljana

The present study reports on and discusses new records for the Slovenian spider fauna, namely: Asthenargus bracianus, Clubiona leucaspis, Euryopis laeta, Lasaeola prona, Lathys stigmatisata, Meioneta innotabilis, Oecobius maculatus, Porrhomma microphthalmum, Trichoncus saxicola and Zodarion pusio. According to their areas of distribution and confir...

Aureobasidium melanogenum is a black yeast-like fungus that occurs frequently both in nature and in domestic environments. It is becoming increasingly important as an opportunistic pathogen. Nevertheless, its effect on human cells has not yet been studied. In this study, we investigated the effect of A. melanogenum cells and extracellular vesicles...

Acanthocephalans are obligatory endoparasites that often alter the phenotype of their invertebrate intermediate host to facilitate trophic transmission to their final vertebrate host. Acanthocephalus anguillae , a widespread parasite of European freshwater fishes and isopod Asellus aquaticus , was recently discovered also in Postojna-Planina Cave S...

Slovensko društvo za mikroskopijo (https://sdm.mikroskopsko-drustvo.si/) že od leta 2015 redno organizira znanstveno-strokovna srečanja z naslovom 'Slovensko posvetovanje mikroskopistov'. Tako je 16. in 17. maja 2024 na Rogli potekalo že 5. slovensko posvetovanje mikroskopistov, povzetki vseh prispevkov so dostopni na strani: https://www.mikroskops...

Essential oils are promising antimicrobial agents against various bacteria. The aim of the study was to examine anti-Acinetobacter baumannii activity of nine essential oils and to elucidate essential oil mechanisms of action against this. In total, 8 out of 9 examined different essential oils exhibited activity against multidrug-resistant (MDR) A....

Francisella is a highly infectious gram-negative bacterium that causes tularemia in humans and animals. It can survive and multiply in a variety of cells, including macrophages, dendritic cells, amoebae, and arthropod-derived cells. However, the intracellular life cycle of a bacterium varies depending on the cell type. Shortly after the infection o...

Haematological investigation is an important component of stress and immune response assessment and holds great potential for evaluating amphibian welfare. The olm (Proteus anguinus) is a neotenic, cave-dwelling salamander endemic to the Dinaric Karst and classified as a vulnerable species by the IUCN. The aim of the present study was to gain basic...

High‐density genotyping methods have revolutionized the field of population and conservation genetics in the past decade. To exploit the technological and analytical advances in the field, access to high‐quality genetic material is a key component. However, access to such samples in endangered and rare animals is often challenging or even impossibl...

Ants from the Formica rufa group, also known as red wood ants, build large mound nests and play an important role in their environment, especially in forests. Their nests harbour a species rich and abundant myrmecophilous fauna, including a few European spider species. Myrmecophilous spiders in 40 nests of red wood ants from 25 sites were searched...

The present study discusses and reports on 29 spider species new to Slovenian fauna, specifically: Larinioides patagiatus, Cyrtarachne ixoides, Pritha nana, Marinarozelotes adriaticus, Micaria micans, Scotophaeus blackwalli, Zelotes similis, Agyneta orites, Donacochara speciosa, Lasiargus hirsutus, Trichoncus sordidus, Walckenaeria vigilax, Alopeco...

Filamentous bacteriophages belonging to the order Tubulavirales, family Inoviridae, significantly affect the properties of Gram-negative bacteria, but filamentous phages of many important pathogens have not been described so far. The aim of this study was to examine A. baumannii filamentous phages for the first time and to determine their effect on...

Despite the established concept of the human mammary gland (MG) as a habitat with its own microbiota, the exact mechanism of MG colonization is still elusive and a well-characterized in vitro model would reinforce studies of the MG microbiota development. We aimed to establish and characterize an in vitro cell model for studying MAmmary Gland mIcro...

The article presents the history of the journal Natura Sloveniae over the 25 years, from 1999–2023, of its publication. The main aim of the journal is highlighted, as well as a brief analysis of the number of contributions and authors, the taxonomic groups covered in the articles, including an overview of the citation success of the articles publis...

During the 2021 European Food Safety Authority coordinated harmonized monitoring of antimicrobial resistance in Campylobacter species in Slovenia, five Campylobacter -like strains were cultured from caeca of a total of 104 domestic pigs that could not be identified using the standard-prescribed biochemical tests or MALDI-TOF MS. The isolates were o...

The investigation of the microbial community change in the biofilm, growing on the walls of a containment tank of TRIGA nuclear reactor revealed a thriving community in an oligotrophic and heavy-metal-laden environment, periodically exposed to high pulses of ionizing radiation (IR). We observed a vertical IR resistance/tolerance stratification of m...

Subchondroplasty is a new minimally invasive surgical technique developed to treat bone marrow lesions (BML) and early osteoarthritis (OA). During the procedure, engineered calcium phosphate compound (CPC) is injected. It is claimed by the manufacturer that during the healing process, the CPC is replaced with new bone. The purpose of this study was...

The self-binding of bacterial cells, or autoaggregation, is, together with surface colonization, one of the first steps in the formation of a mature biofilm. In this work, the autoaggregation of B. subtilis in dilute bacterial suspensions was studied. The dynamics of cell lysis, eDNA release, and bacterial autoaggregate assembly were determined and...

Bacillus thuringiensis serovar israelensis is the most widely used biopesticide against insects, including vectors of animal and human diseases. Among several extrachromosomal elements, this endospore-forming entomopathogen harbors two bacteriophages: a linear DNA replicon named GIL01 that does not integrate into the chromosome during lysogeny and...

Seven Helicobacter -like isolates were cultured from caecal contents of 100 domestic pigs ( Sus scrofa domesticus ) sampled as part of the EFSA-coordinated harmonized monitoring of antimicrobial resistance in Campylobacter sp. in 2015. The bacteria were isolated using the standard ISO 10272 procedure for the isolation of thermotolerant Campylobacte...

Extracellular vesicles (EVs) are increasingly recognized as an important mechanism for cell–cell interactions. Their role in fungi is still poorly understood and they have been isolated from only a handful of species. Here, we isolated and characterized EVs from Aureobasidium pullulans, a biotechnologically important black yeast-like fungus that is...

The olm ( Proteus anguinus ), an endemic amphibian of the Dinarides’ underground waters (Europe), is one of the world’s most widely known subterranean species. Although various aspects of olm biology have been extensively studied, the data on their behavior in the wild remain scarce mostly due to inaccessibility of their natural habitat. Yet, olms...

Encapsulation of a selected DNA molecule in a cell has important implications for bionanotechnology. Non-viral proteins that can be used as nucleic acid containers include proteinaceous subcellular bacterial microcompartments (MCPs) that self-assemble into a selectively permeable protein shell containing an enzymatic core. Here, we adapted a propan...

Proteus anguinus is a neotenic cave salamander, endemic to the Dinaric Karst and a symbol of world natural heritage. It is classified as “vulnerable” by the International Union for Conservation of Nature (IUCN) and is one of the EU priority species in need of strict protection. Due to inaccessibility of their natural underground habitat, scientific...

Heavily pigmented glacier ice algae Ancylonema nordenskiöldii and Ancylonema alaskanum (Zygnematophyceae, Streptophyta) reduce the bare ice albedo of the Greenland Ice Sheet, amplifying melt from the largest cryospheric contributor to eustatic sea-level rise. Little information is available about glacier ice algae interactions with other microbial...

The phylum Chlamydiae consists of obligate intracellular bacteria including major human pathogens and diverse environmental representatives. Here we investigated the Rhabdochlamydiaceae, which is predicted to be the largest and most diverse chlamydial family, with the few described members known to infect arthropod hosts. Using published 16 S rRNA...

Cave animals are biological models of fast evolutionary change induced by transition to extreme subterranean environments. But their concealed lifestyle makes it inherently difficult to study life-history changes. Therefore, currently very little is known on the reproduction of cave species, and even less is known on general patterns and potentiall...

Background:Lightless caves can harbour a wide range of living organisms. Cave animals have evolved a set of morphological, physiological, and behavioural adaptations known as troglomorphisms, enabling their survival in the perpetual darkness, narrow temperature and humidity ranges, and nutrient scarcity of the subterranean environment. In this stud...

In this study, we link pellicle development at the water–air interface with the vertical distribution and viability of the individual B. subtilis PS-216 cells throughout the water column. Real-time interfacial rheology and time-lapse confocal laser scanning microscopy were combined to correlate mechanical properties with morphological changes (aggr...

The phylum Chlamydiae consists of obligate intracellular bacteria including major human pathogens and diverse environmental representatives. Here we investigated the Rhabdochlamydiaceae, which is predicted to be the largest and most diverse chlamydial family, with the few described members known to infect arthropod hosts. Using published 16S rRNA g...

With only 43 described stygobionts and only two isopod species the obligate groundwater fauna of Iran, a vast country with over 10% of limestone surface, is inadequately known. Here, we report the discovery of Asellus ismailsezarii sp. nov. from Zagros mountains, the first eyeless and depigmented asellid isopod from Iran. The new species is morphol...

Two different morphologies of ferroelectric bismuth titanate (Bi4Ti3O12) nanoparticles, i.e., nanoplatelets and nanowires, were synthesized by changing the concentration of NaOH during a hydrothermal treatment of precipitated Ti4+ and Bi3+ ions. The nanoparticles' crystal structures were characterized using atomic-resolution imaging with a CS-probe...

The applications of bacterial sonolysis in industrial settings are plagued by the lack of the knowledge of the exact mechanism of action of sonication on bacterial cells, variable effectiveness of cavitation on bacteria, and inconsistent data of its efficiency. In this study we have systematically changed material properties of E. coli cells to pro...

Zaradi stalne interakcije organizmov z okoljem so le ti tekom evolucije razvili zmožnost prepoznavanja in razlikovanja med lastnimi in tujimi molekulami in oblikovanja ustreznega odziva na tujke, kar je temeljna funkcija imunskega sistema. Enakonožci Porcellio scaber so predstavniki kopenskih rakov, podobno kot tudi druge skupine rakov pa imajo raz...

In parasite-host interactions host species may differ in their ability to fight parasitic infections, while other ecological interactions, including competition, may differentially alter their physiological state, making them even more susceptible to parasites. In this study, we analyze the haemogregarine blood parasites infecting two competing liz...

Deciphering the genetic code of organisms with unusual phenotypes can help answer fundamental biological questions and provide insight into mechanisms relevant to human biomedical research. The cave salamander Proteus anguinus (Urodela: Proteidae), also known as the olm, is an example of a species with unique morphological and physiological adaptat...

Ostreolysin A6 (OlyA6) is a protein produced by the oyster mushroom (Pleurotus ostreatus). It binds to membrane sphingomyelin/cholesterol domains, and together with its protein partner, pleurotolysin B (PlyB), it forms 13-meric transmembrane pore complexes. Further, OlyA6 binds 1000 times more strongly to the insect-specific membrane sphingolipid,...

Bacillus subtilis is a soil bacterium that is competent for natural transformation. Genetically distinct B. subtilis swarms form a boundary upon encounter, resulting in killing of one of the strains. This process is mediated by a fast-evolving kin discrimination (KD) system consisting of cellular attack and defence mechanisms. Here, we show that th...

The surface structures and mucus layers that form an interface between the epithelial layer of organisms and their external environment were studied in the bloom-forming moon jellyfish (Aurelia solida, Scyphozoa) from the northern Adriatic. The surface of the polyps revealed epithelial ciliated cells and numerous nematocysts, both non-discharged an...

Aegerolysins are proteins produced by bacteria, fungi, plants and protozoa. The most studied fungal aegerolysins share a common property of interacting with membranes enriched with cholesterol in combination with either sphingomyelin or ceramide phosphorylethanolamine (CPE), major sphingolipids in the cell membranes of vertebrates and invertebrates...

jats:title>Abstract Emerging infections add to existing threats to the survival of amphibians worldwide. The olm ( Proteus anguinus ) is a vulnerable, troglobiont urodele species with a small European range and restricted to underground karstic systems. Population declines to emerging threats like the chytrid fungus Batrachochytrium salamandrivoran...

Virusi v vodnih okoljih so bili v zadnjem desetletju intenzivno preučevani, vendar pa virusi v jamskih vodah ostajajo slabo opisani. Cilj raziskave je bila karakterizacija viroma vode vzorčene v različnih jamah, v katerih živijo tudi predstavniki vrste Proteus anguinus oziroma človeške ribice. Predstavniki dvoživk, ki živijo v tako občutljivih vodn...

The terrestrial crustacean Porcellio scaber (Crustacea: Isopoda) is an established invertebrate model in environmental research. Preceding research using isopods did not widely use immune markers. In order to advance their use in research, knowledge of the reference values in control animals as well as variations during infections is of importance....

Aquatic viruses have been extensively studied over the past decade, yet aspects of virus communities in cave waters remain poorly described. Our goal was to characterize viromes of cave water sampled in oligotrophic environments where Proteus anguinus, also known as olm or European cave salamander is present. Due to their dependence on, in many cas...

The neurotropic and extremophilic black yeast Exophiala dermatitidis (Herpotrichellaceae) inhabits diverse indoor environments, in particular bathrooms, steam baths, and dishwashers. Here, we show that the selected strain, EXF-10123, is polymorphic, can grow at 37°C, is able to assimilate aromatic hydrocarbons (toluene, mineral oil, n-hexadecane),...

(1) Background: Mechanisms of cellular and molecular adaptation of fungi to salinity have been commonly drawn from halotolerant strains and few studies in basidiomycete fungi. These studies have been conducted in settings where cells are subjected to stress, either hypo- or hyperosmotic, which can be a confounding factor in describing physiological...

Cacopsylla picta (Förster, 1848) (Hemiptera: Pysllidae) is the main vector of apple proliferation, a phytoplasma-caused disease. It represents one of the most severe problems in apple orchards, and therefore, there is a mandatory requirement to chemically treat against this pest in the European Union. Sexual communication using substrate-borne vibr...

Despite established concept of mammary gland (MG) as microbial habitat with its own microbiota, the exact mechanism of MG colonisation is still elusive. The objective of this study was to thoroughly characterise in vitro cell culture model for study of MG microbial colonisation (MAGIC model). For the MAGIC model, we used immortalized cell line MCF...

Acanthocephalus balkanicus Batchvarov et Combes, 1974 was incompletely described from the northern crested newt, Trit-urus cristatus (Laurenti) (Amphibia: Salamandridae), a possible synonym of the Balkan crested newt, Triturus ivanbureschi Arntzen et Wielstra, from a pond in village of Pesnopoy, southern Bulgaria. We provide a full description of a...

B. subtilis is a soil dwelling bacterium with a diverse social life that includes quorum sensing-regulated interactions. These interactions result in bacterial equivalent of sex, and subsequently have a profound influence on bacterial evolution. Sexual isolation in B. subtilis predicts for more frequent uptake of DNA isolated from closely related m...

We provide a list of 171 spider species from 27 families recently recorded in Slovenia. Among them are first records of Nigma flavescens, Walckenaria alticeps, Pelecopsis parallela, Erigone autumnalis and Micaria subopaca for Slovenia and a second record of Zodarion rubidum, a species just recently added to the Slovenian spider fauna.

Vitellogenin (Vtg) is a precursor protein of egg yolk proteins in oviparous and ovoviviparous vertebrates. Except in a case of exposure to estrogenic endocrine disruptors, Vtg is a female-specific protein and could be used as a molecular marker for sex identification. This would be especially useful in the case of the endangered European cave salam...

Sixteen spider species, new to the Slovenian fauna, have been recorded: Aphantaulax trifasciata, Araneus triguttatus, Arctosa cinerea, Cnephalocotes obscurus, Helophora insignis, Heriaeus hirtus, Nomisia exornata, Nurscia albomaculata, Pardosa agricola, Pardosa prativaga, Pardosa proxima, Philodromus longipalpis, Runcinia grammica, Theridula gonyga...

The Olm or proteus (Proteus anguinus) is the only vertebrate in Europe fully adapted to cave life, in Slovenia protected since 1951. The Tular Cave Laboratory is specialized on research and conservation of proteus, with long-term isolated ex situ captive breeding since 1960. The laboratory also manages a sanctuary for injured proteus (e.g., animals...

The European cave salamander Proteus anguinus is a charismatic amphibian endemic to the concealed and inaccessible subterranean waters of the Dinaric Karst. Despite its exceptional conservation importance not much is known about its ecology and interactions with the groundwater microbiome. The cutaneous microbiota of amphibians is an important driv...

Nanocomposites with a high and uniform loading of magnetic nanoparticles are very desirable for various applications. In this study, a simple and scalable route for preparing nanocomposites with a high and uniform loading of magnetic nanoparticles is presented. The magnetic iron-oxide nanoparticles were functionalized with a methacrylate-based mono...

Proteus anguinus is a neotenic cave amphibian endemic to the Dinaric Karst and represents a symbol of Slovenian natural heritage. It is classified as 'Vulnerable' by the International Union for Conservation of Nature (IUCN) and is one of the EU priority species in need of strict protection. Due to inaccessibility of its natural underground habitat,...

Nanocomposites with a high, uniform loading of magnetic nanoparticles are very desirable for applications such as electromagnetic shielding and cancer treatment based on magnetically induced hyperthermia. In this study, a simple and scalable route for preparing nanocomposites with a high, uniform loading of magnetic nanoparticles is presented. The...

Additional experimental information.

It is generally accepted that planktonic bacteria in dilute suspensions are not mechanically coupled and do not show correlated motion. The mechanical coupling of cells is a trait that develops upon transition into a biofilm, a microbial community of self-aggregated bacterial cells. Here we employ optical tweezers to show that bacteria in dilute su...

Parasites are important drivers for shaping populations; they can significantly affect clutch size, hatching success, and individual’s survival, among others. In ecologically similar host species shared parasites may shape the interspecific interaction. Our goal is to investigate the role of parasites in shaping populations of two lizard species: I...

As other amphibians kept in artificial or semi-natural environments, the specimens of troglomorphic Proteus anguinus are susceptible to opportunistic microbial infections, due to the suppressed defensive mechanisms of the host exposed to stress or suboptimal living conditions. Despite absence of published data on infection of Proteus in captivity,...

In Central Europe, reports of human envenomation by Cheiracanthium punctorium, commonly known as the yellow sac spider, are sporadic, despite the fact that this species is widespread in Europe. However, in recent years, C. punctorium has been repeatedly described globally in medical and toxicological literature. Its venom was found to possess insec...

The soil is a heterogeneous habitat with layers that differ in many aspects and soil animals' morphological adaptations relate to specific microhabitat. We compared cuticle surface structures and ultrastructure of Balloniscus glaber (endogeic) and Atlantoscia floridana (epigeic) using microscopy techniques to understand how morphological characteri...

Terrestrial isopods from the group Trichoniscidae accumulate calcium in specialized organs, known as the calcium bodies. These consist of two pairs of epithelial sacs located alongside the digestive system. These organs contain various forms of calcium and constantly present bacteria. To elucidate their origin and role, we analyzed the bacteria of...

Bordetella bronchiseptica is a well-known etiological agent of kennel cough in dogs and cats and one of the two causative agents of atrophic rhinitis, a serious swine disease. The aim of the study was to isolate B. bronchiseptica bacteriophages from environmental samples for the first time. A total of 29 phages from 65 water samples were isolated u...

Extended abstract: Apple proliferation (AP) is a phytoplasma-caused disease widespread in many European regions, and represents a serious problem in Italian apple orchards. The etiological agent 'Candidatus Phytoplasma mali' causes symptoms that suggest profound disorders in the normal balance of plant hormones or growth regulators in infected plan...

A 3-month-old dog originating from a Slovenian animal shelter presented with acute bloody, soft, foamy and malodorous diarrhoea. The clinical examination, haematology and serum biochemistry were unremarkable. Ultrasonography of the abdomen showed prominent mesenteric lymph nodes and the presence of echogenic content within the small intestine. Ligh...

Being the most numerous, diverse and ubiquitous group of animals, the arthropods have established a wide array of interactions with bacteria. Despite their considerable potential in agriculture, health‐care and pest control, exploration of these associations is limited to a few well studied associations (Bourtzis & Miller 2003), while comprehensive...

Hadesia is a charismatic and scientifically important genus of cave beetles. It is a classical representative of the subterranean fauna of the Dinaric Karst and the model upon which the ultra-specialized ecomorphological form of semi-aquatic, hygropetricolous filter feeders became known. We describe a new species, Hadesia zetae sp.n., from southwes...

In this paper we review the research on aquatic and terrestrial isopods during the last four decades at the Chair of Zoology, Department of Biology, Biotech- nical Faculty, University of Ljubljana. Isopods have attracted substantial attention from our research team in the followingareas: functional morphology and developmental biology, host-microbi...

Abstract. The study reports on first records of two spider species for Slovenian fauna, Zodarion rubidum and Prinerigone vagans from the Bela krajina region in southeastern Slovenia. Regarding their presence in the neighbouring countries and distribution in Europe, both species could be considered as expected. The finding of Z. rubidum during night...