Bat casualties on a road crossing a mosaic landscape

A year-round study was conducted on a 16.6-km road section crossing Kampinos National Park near Warsaw (central Poland). We found 61 road-killed bats belonging to seven species. The most abundant were: Nyctalus noctula, Plecotus auritus, and Barbastella barbastellus. Bats were found between the middle of April and the end of October with peaks in July/August and October. The density of bat casualties differed slightly in various habitats surrounding the road—lower values than expected were found only for windbreaks and bushes. The prediction that low-flying species are killed more frequently was not confirmed—the most abundant N. noctula usually flies at heights over 10 m above the ground. N. noctula, Myotis nattereri, and Pipistrellus nathusii were killed more frequently while Eptesicus serotinus less frequently than could be expected from the frequency with which they were captured in mist-nets on forest lanes.     

Cellobiose dehydrogenase from the ligninolytic basidiomycete Phlebia lindtneri

Cellobiose dehydrogenase (CDH), an extracellular flavocytochrome produced by several wood-degrading fungi, was detected in the culture supernatant of the selective delignifier Phlebia lindtneri maintained on a cellulose-based liquid medium. Cellobiose dehydrogenase was purified to homogeneity by a rapid procedure, using ammonium sulfate precipitation, ion-exchange chromatography, and chromatofocusing. The enzyme was recovered with a 61.2 fold increased specific activity and a yield of 47.5%. As determined by SDS-PAGE, the molecular mass of the purified enzyme was found to be 104.5 kDa and its isoelectric point was 4.0. The carbohydrate content of the purified enzymes was 22%. In this work, the cellobiose dehydrogenase gene cdh1 and its corresponding cDNA from fungi Phlebia lidnteri were isolated, cloned, and characterized. The 2319 bp full-length cDNA of cdh1 encoded a mature CDH protein containing 755 amino acids, which was preceded by a signal peptide of 17 amino acids. The deduced protein sequence of cdh1 shared significant similarity with other known fungal cellobiose dehydrogenase.     

On the Importance of Oxidative Folding in the Evolution of Conotoxins: Cysteine Codon Preservation through Gene Duplication and Adaptation

Conotoxin genes are among the most rapidly evolving genes currently known; however, despite the well-established hypervariability of the intercysteine loops, the cysteines demonstrate significant conservation, with a site-specific codon bias for each cysteine in a family of conotoxins. Herein we present a novel rationale behind the codon-level conservation of the cysteines that comprise the disulfide scaffold. We analyze cysteine codon conservation using an internal reference and phylogenetic tools; our results suggest that the established codon conservation can be explained as the result of selective pressures linked to the production efficiency and folding of conotoxins, driving the conservation of cysteine at the amino-acid level. The preservation of cysteine has resulted in maintenance of the ancestral codon in most of the daughter lineages, despite the hypervariability of adjacent residues. We propose that the selective pressures acting on the venom components of cone snails involve an interplay of biosynthetic efficiency, activity at the target receptor and the importance of that activity to effective prey immobilization. Functional redundancy in the venom can thus serve as a buffer for the energy expenditure of venom production.     

Molecular characteristics of Polish field strains of Marek's disease herpesvirus isolated from vaccinated chickens

Background  

Twenty-nine Marek's disease virus (MDV) strains were isolated during a 3 year period (2007-2010) from vaccinated and infected chicken flocks in Poland. These strains had caused severe clinical symptoms and lesions. In spite of proper vaccination with mono- or bivalent vaccines against Marek's disease (MD), the chickens developed symptoms of MD with paralysis.     

Peptidoglycan hydrolases-potential weapons against Staphylococcus aureus

Bacteria of the genus Staphylococcus are common pathogens responsible for a broad spectrum of human and animal infections and belong to the most important etiological factors causing food poisoning. Because of rapid increase in the prevalence of isolation of staphylococci resistant to many antibiotics, there is an urgent need for the development of new alternative chemotherapeutics. A number of studies have recently demonstrated the strong potential of peptidoglycan hydrolases (PHs) to control and treat infections caused by this group of bacteria. PHs cause rapid lysis and death of bacterial cells. The review concentrates on enzymes hydrolyzing peptidoglycan of staphylococci. Usually, they are characterized by high specificity to only Staphylococcus aureus cell wall components; however, some of them are also able to lyse cells of other staphylococci, e.g., Staphylococcus epidermidis-human pathogen of growing importance and also other groups of bacteria. Some PHs strengthen the bactericidal or bacteriostatic activity of common antibiotics, and as a result, they should be considered as component of combined therapy which could definitely reduced the development of bacterial resistance to both enzymes and antibiotics. The preliminary research revealed that most of these enzymes can be produced using heterologous, especially Escherichia coli expression systems; however, still much effort is required to develop more efficient and large-scale production technologies. This review discusses current state on knowledge with emphasis on the possibilities of application of PHs in the context of therapeutics for infections caused by staphylococci.     

Spectroscopic studies of amphotericin B–Cu<Superscript>2+</Superscript> complexes

The aim of this research is to investigate amphotericin B (AmB)–Cu²⁺ complexes in aqueous solution at different pH values. Electronic absorption, circular dichroism (CD), Raman and FTIR spectroscopies were used in this study. We found that different concentrations of AmB and Cu²⁺ ions in solution leads to formation of complexes with stoichiometry of 2:1 and 1:1. The formation of AmB–Cu²⁺ complexes at physiological pH values is accompanied by changes of the molecular organization of AmB especially disaggregation. These observed effects might be significant from a medical point of view.