Enterococcus in wound infections: virulence and antimicrobial resistance

Enterococci, a complex group of facultative pathogens have become increasingly isolated in various hospital settings. They are considerable frequently cultured from traumatic and surgical wounds. We investigated 57 strains of the species E. faecalis, E. faecium and E. casseliflavus isolated from infected wounds. Their ability to produce virulence factors and their sensitivity to antibiotics were evaluated using phenotypic and genotyping methods. In the phenotype studies, significant portion of the isolates produced biofilm (66.7%) and gelatinase (36.8%). Nearly 30% of the strains expressed hemolytic properties. Only a few produced DNAse (15.8%) and lipase (7.0%). The genes esp, gelE, cylA, cylB, cylM and agg were detected in most of the isolates (38.6-87.7%). All the isolated enterococci were susceptible to vancomycin and were characterized by their low resistance to antibiotics, except aminoglycosides (HLR).     

Effect of climate,topography and habitat on species-richness of breeding birds in Poland

We developed predictive maps of farmland and forest species richness which are based on the “focal species concept” and remote sensing data. We explored environmental preferences of 17 farmland and 33 forest species in Poland, using data from the Pan-European Monitoring Scheme. The largest number of farmland species was noted in the central and eastern parts, while the opposite trend was observed in the case of forest species, where the preferred areas were in the north and south-east. The most important environmental component affecting the bird faunas of farmland and forest was a gradient from arable fields to forest. This relationship is unimodal, which means that on a meso-geographical scale the highest species richness occurred in heterogeneous landscapes where fields are interspersed with forest. Our results also indicate that the geographical gradient in Poland's bird fauna can simply be attributed to the habitat-based distinction: western and central parts are dominated by large agricultural habitats and coniferous forest, while in other areas predominate mixed forests and extensively used farmland. Among the climatic factors, only rainfall influenced the farmland bird species. Its effect is non-linear, but positive, which means that in areas with higher rainfall more species are recorded.Our predictive maps are complementary to research on population trends, and can be an essential tool for effective management and conservation of species populations on a trans-national scale.     

U12-type spliceosomal introns of Insecta

Most of eukaryotic genes are interrupted by introns that need to be removed from pre-mRNAs before they can perform their function. This is done by complex machinery called spliceosome. Many eukaryotes possess two separate spliceosomal systems that process separate sets of introns. The major (U2) spliceosome removes majority of introns, while minute fraction of intron repertoire is processed by the minor (U12) spliceosome. These two populations of introns are called U2-type and U12-type, respectively. The latter fall into two subtypes based on the terminal dinucleotides. The minor spliceosomal system has been lost independently in some lineages, while in some others few U12-type introns persist. We investigated twenty insect genomes in order to better understand the evolutionary dynamics of U12-type introns. Our work confirms dramatic drop of U12-type introns in Diptera, leaving these genomes just with a handful cases. This is mostly the result of intron deletion, but in a number of dipteral cases, minor type introns were switched to a major type, as well. Insect genes that harbor U12-type introns belong to several functional categories among which proteins binding ions and nucleic acids are enriched and these few categories are also overrepresented among these genes that preserved minor type introns in Diptera.     

Bread matters: a national initiative to profile the genetic diversity of Australian wheat

The large and complex genome of wheat makes genetic and genomic analysis in this important species both expensive and resource intensive. The application of next-generation sequencing technologies is particularly resource intensive, with at least 17?Gbp of sequence data required to obtain minimal (1×) coverage of the genome. A similar volume of data would represent almost 40× coverage of the rice genome. Progress can be made through the establishment of consortia to produce shared genomic resources. Australian wheat genome researchers, working with Bioplatforms Australia, have collaborated in a national initiative to establish a genetic diversity dataset representing Australian wheat germplasm based on whole genome next-generation sequencing data. Here, we describe the establishment and validation of this resource which can provide a model for broader international initiatives for the analysis of large and complex genomes.     

One-pot synthesis of new (1,3-thiazolo[5,4-b]pyridin-2-yl)benzenediols and their antiproliferative activities against human cancer cell lines

A one-pot synthesis of new 4-(1,3-thiazolo[5,4-b]pyridin-2-yl)benzene-1,3-diols has been described. The compounds were prepared by the reaction of sulfinylbis[(2,4-dihydroxyphenyl)methanethione] derivatives, with various substituents in the aryl rings, with 2-chloropyridin-3-amines. Their structures were deduced from IR and, (1) H- and (13) C-NMR spectroscopic, mass spectrometric, and elemental analyses. The antiproliferative properties of some of the products against human cancer cell lines were comparable to those of cisplatin. Structure-activity analysis showed that the presence of hydrophobic substituents in both heterocyclic fused and phenyl rings of the compounds improves their biological effects. Further, an additional OH group in the resorcinol moiety reduced the antiproliferative activity.     

Expression of ghrelin receptor (GHSR-1a) in rat epididymal spermatozoa and the effects of its activation

In this study we demonstrated the expression of the ghrelin receptor GHSR-1a in rat spermatids and epididymal spermatozoa, as well as some effects of ghrelin on the spermatozoa in vitro. For the demonstration of GHSR-1a the immunocytochemical, immunofluorescence and Western blotting techniques were applied using three different types of antibodies. The response of spermatozoa to ghrelin was tested in a series of in vitro experiments and their effects were evaluated using confocal microscopy and flow cytometry. GHSR-1a protein was found as expressed in the Golgi and acrosomes of spermatids and acrosome regions or the head cell membrane of epididymal spermatozoa. The GHSR-1a expression in spermatozoa was also confirmed by Western blot. No differences were found in percentage of spermatozoa showing annexin-V binding and expression of active form caspase-3 between control and ghrelin-treated spermatozoa. This result may indicate no pro-apoptotic effects of ghrelin neither at 10^?9 nor 10^?6 mol/L concentration. Ghrelin (10^?6 mol/L) increased free intracellular calcium ion concentration in the rat spermatozoa. Moreover, stimulation with 10^?6 mol/L ghrelin increased, while 10^?4 mol/L ghrelin decreased the number of spermatozoa showing progressive motility. In conclusion, the expression of the GHSR-1a receptor in spermatozoa, as well as ghrelin influences on sperm motility and intracellular calcium ion concentration suggest that such biological effects of ghrelin may be produced under in vivo conditions.     

CYP17 and CYP19 genetic variants are not associated with age at natural menopause in Polish women

The aim of the study was to investigate associations between two common polymorphisms of CYP17 and CYP19, encoding key enzymes of estrogen biosynthesis, and age at menopause in Polish women. One hundred fifty women after menopause (49.5 ± 3.8 years), with no previous history of hormone replacement therapy took part in the study. The genetic control group consisted of 150 newborns from the same population. We investigated an association between the age at menopause and the single nucleotide polymorphism T → C in the 5′ untranslated region (promoter) of the CYP17 gene (c.-34T>C; rs743572 – MspA1) or the number of tetranucleotide repeats [TTTA]_n (rs60271534) including deletion/insertion (D/I) of a 3 bp sequence in intron 4 of the CYP19 gene. CYP17 polymorphism was analyzed by PCR-RFLP and CYP19 by PCR and capillary electrophoresis. In the case of CYP17 polymorphism, 28.7% and 36.7% wild homozygous (TT), 50.7% and 46.0% heterozygous (TC), as well as 20.6% and 17.3% mutated homozygous (CC) types were identified in the subjects and controls, respectively. The frequency of mutated alleles (C) was 46.0% vs. 40.3% (p = 0.19). In the case of CYP19 polymorphism, 34.0% and 32.0% of homozygotes (1_1), 50.7% and 51.3% of heterozygotes (1_2), 15.3% and 16.7% of homozygotes (2_2) were identified in the subjects and controls, respectively. No association between the studied CYP17 or CYP19 polymorphisms and age at menopause was found in Polish women.     

Design, synthesis and evaluation of the inhibitory selectivity of novel trans-resveratrol analogues on human recombinant CYP1A1, CYP1A2 and CYP1B1

A series of trans-stilbene derivatives containing 4'-methylthio substituent were synthesized and evaluated for inhibitory activities on human recombinant cytochrome P450(s): CYP1A1, CYP1A2, and CYP1B1. CYP1A2-related metabolism of stilbene derivatives was estimated by using NADPH oxidation assay. Additionally, for CYP1A2 and CYP1B1 molecular docking analysis was carried out to provide information on enzyme-ligand interactions and putative site of metabolism. 3,4,5-Trimethoxy-4'-methylthio-trans-stilbene, an analogue of DMU-212 (3,4,5,4'-tetramethoxy-trans-stilbene) was an effective inhibitor of all CYP1 enzymes. On the other hand, 2,3,4-trimethoxy-4'-methylthio-trans-stilbene, appeared to be the most selective inhibitor of the isozymes CYP1A1 and CYP1B1, displaying extremely low affinity towards CYP1A2. Molecular modeling suggested that the most probable binding poses of the methylthiostilbene derivatives in CYP1A2 active sites are those with the methylthio substituent directed towards the heme iron. Products of CYP1A2-catalyzed oxidation of 2,4,5-trimethoxy-4'-methylthiostilbene and 3,4,5-trimethoxy-4'-methylthiostilbene were identified as monohydroxylated compounds. Other studied derivatives appeared to be poor substrates of CYP1A2. Structure-activity relationship analysis rendered better understanding of the mechanism of action of xenobiotic-metabolizing enzymes crucial at the early stage of carcinogenesis.