Occurrence of Wolbachia in central European weevils: correlations with host systematics,ecology, and biology

We studied the occurrence of Wolbachia in relation to the systematics, ecology, and biology of 40 weevil species from central Europe. Identification of Wolbachia supergroups and phylogeny was performed on the basis of 16S rDNA, ftsZ, wsp, and hcpA sequences. Sixteen species (40%) were infected by Wolbachia. Six of these possess only supergroup A (15% of all studied species, 37.5% of the infected species), and four harbored only supergroup B (10 and 25%, respectively). Six species were infected by both supergroups A and B or their genomes harbored parts of these two supergroups (15 and 37.5%, respectively). No differences between Wolbachia supergroup frequencies were detected. There was almost no correlation between Wolbachia phylogeny and host systematics and phylogeny at the level of subfamily and tribe, because the representatives of both supergroups were detected in all the studied multi‐species tribes. Wolbachia strains were probably inherited from a common ancestor only in the case of the genus Strophosoma, where two of three analyzed species possessed bacteria which are genetically very close in all the studied genes. There was also only limited congruence between phylogenies obtained from the four studied genes. These results suggest horizontal transmission of Wolbachia strains between species and recombination events between different strains. A significant correlation was detected between infected and uninfected species in relation to mobility (flying species were 2× more frequently infected than non‐flying species), foraging (polyphagous species were 2.5× less frequently infected than mono‐ or oligophagous species), and reproductive mode (parthenogenetic weevils were infected nearly 2× as often as bisexuals). No differences were detected between mesophilous and xerothermophilous species, nor between those inhabiting open areas vs. arboreal species. However, these results might have been influenced by common ancestry among the studied weevils. Because weevils include many plant pests of economic importance, it is possible to use these data in developing alternative, biology‐based strategies for controlling them.     

Screening concepts,characterization and structural analysis of microbial-derived bioactive lipopeptides: a review

Lipopeptide biosurfactants are surface active biomolecules that are produced by a variety of microorganisms. Microbial lipopeptides have gained the interest of microbiologists, chemists and biochemists for their high biodiversity as well as efficient action, low toxicity and good biodegradability in comparison to synthetic counterparts. In this report, we review methods for the production, isolation and screening, purification and structural characterization of microbial lipopeptides. Several techniques are currently available for each step, and we describe the most commonly utilized and recently developed techniques in this review. Investigations on lipopeptide biosurfactants in natural products require efficient isolation techniques for the characterization and evaluation of chemical and biological properties. A combination of chromatographic and spectroscopic techniques offer opportunities for a better characterization of lipopeptide structures, which in turn can lead to the application of lipopeptides in food, pharmaceutical, cosmetics, agricultural and bioremediation industries.     

Molecular diagnosis of cystic echinococcosis in humans from central Poland

The identity of the causative agent of cystic echinococcosis (CE) in humans from central Poland receiving treatment between 2000 and 2010 was determined. A total of 47 samples obtained after hepatectomy were examined and protoscoleces were identified in wet preparations in 27 cases. Using DNA extracted from the samples, two mitochondrial regions (nad1 and cox1 genes) were amplified and the nad1 fragment was sequenced. This PCR analysis confirmed the presence of Echinococcus species in 30 cases and nad1 sequence alignments showed identity with the G7 (pig) strain, Echinococcus canadensis. These data demonstrate that the pig strain of this parasite is the most frequent causative agent of human cystic echinococcosis in central Poland.     

Structural Model of the Bilitranslocase Transmembrane Domain Supported by NMR and FRET Data

We present a 3D model of the four transmembrane (TM) helical regions of bilitranslocase (BTL), a structurally uncharacterized protein that transports organic anions across the cell membrane. The model was computed by considering helix-helix interactions as primary constraints, using Monte Carlo simulations. The interactions between the TM2 and TM3 segments have been confirmed by Förster resonance energy transfer (FRET) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy, increasing our confidence in the model. Several insights into the BTL transport mechanism were obtained by analyzing the model. For example, the observed cis-trans Leu-Pro peptide bond isomerization in the TM3 fragment may indicate a key conformational change during anion transport by BTL. Our structural model of BTL may facilitate further studies, including drug discovery.     

Shoot anatomy and secretory structures in Hypericum species (Hypericaceae)

The anatomy and ultrastructure of internodes, leaves and petals were compared in Hypericum elegans, H. inodorum, H. olympicum, H. forrestii and two genotypes of H. perforatum. Internode anatomy was variable between species with respect to the structure of the cortical and pith parenchyma, including the presence of secretory reservoirs. Also, the secondary growth was more extensive in shrubs, i.e. H. inodorum and H. forrestii. In leaves, phloem secretory reservoirs were formed in all species, mesophyll secretory reservoirs were absent only in H. elegans and internal nodules were present only in H. elegans and H. perforatum. The petals differed between species in the mesophyll structure and the occurrence and location of secretory structures. The phloem secretory reservoirs lacked sheaths, whereas these were distinct in the mesophyll reservoirs. Other ultrastructural traits of the reservoirs were similar in all the species studied, with the exception of the leucoplast ultrastructure. In internal nodules, the inner cells vs. sheath cells differed in the number of vesicles and other membranous structures and plastid ultrastructure. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 163 , 70–86.     

Inhibitory Effect of Eugenol and trans-Anethole Alone and in Combination with Antifungal Medicines on Candida albicans Clinical Isolates

One of the most common pathogens among yeasts is Candida albicans, which presents a serious health threat. The study aimed to check the antifungal properties of trans-anethole and eugenol with selected antifungal medicines (AMs) against C. albicans clinical isolates. The checkerboard method was used to tests of interactions between these compounds. Achieved results indicated that eugenol showed synergistic and additive activities with miconazole and econazole against investigated clinical isolates, respectively. Moreover, the combination – trans-anethole – miconazole also showed an additive effect against two clinical isolate. We tried to relate the results to changes in C. albicans cell sheaths under the influence of essential oils compounds (EOCs) performing the Fourier transform infrared spectra analysis to confirm the presence of particular chemical moieties in C. albicans cells. Nevertheless, no strong relationships was observed between synergistic and additive actions of used EOC-AMs combinations and chemical moieties in C. albicans cells.     

An enemy of your enemy is your friend: Impact of predators on aggregation behavior of gammarids

Predation pressure may affect many aspects of prey behavior, including forming groups and changes in social interactions. We studied the aggregation behavior of competing gammarids Dikerogammarus villosus and Pontogammarus robustoides (Amphipoda, Crustacea) to check whether they modify their preferences for conspecifics or heterospecifics in response to predator (the racer goby Babka gymnotrachelus) kairomones in the presence or absence of stone shelters (alternative protection source). Both species exhibited preferences toward shelters occupied by conspecifics over empty shelters and conspecifics apart from shelters, suggesting that their aggregation depends not only on habitat heterogeneity, but also on their social interactions. Moreover, gammarids in the presence of shelters (safer conditions) preferred conspecifics over heterospecifics, but predator kairomones made them form aggregations irrespective of species. In the predator presence, P. robustoides increased its aggregation level only in the sheltered conditions, whereas D. villosus exhibited this response only in the absence of shelters, suggesting that this behavior can protect it against predators. Therefore, we tested the antipredator effectiveness of D. villosus aggregations by exposing them to fish predation. Gobies foraged most effectively on immobile single gammarids compared to moving and aggregated individuals. Fish also avoided aggregated prey, confirming the protective character of aggregations. We have demonstrated that the predator presence increases aggregation level of prey gammarids and affects their social behavior by reducing antagonistic interactions and avoidance between competing species. This is likely to affect their distribution and functioning in the wild, where predator pressure is a standard situation.     

Induction and stimulation of in vitro flowering of Pharbitis nil by cytokinin and gibberellin

The influence of BA, GA₃ and IAA applied successively onflower bud formation in shoot apices of Pharbitis nil hasbeen investigated. The shoot apices were isolated from seedlings cultivatedunder non-inductive continuous light and from seedlings exposed to asubinductive (12 h) dark period. BA and GA₃ introducedsuccessively into culture medium replaced the inductive night, causing theflowering of plantlets in completely non-inductive continuous light (optimalconcentration of BA – 10^–7–10^–6mol dm^–3, GA₃ –10^–7–10^–6 moldm^–3) and stimulated this process under thesubthresholdinduction. These hormones applied in reverse sequence (in the first placeGA₃, then BA) did not affect flowering of explants. IAA nullifiedthestimulating effect of BA and GA₃. The influence of phytohormones onflowering may result from the change of growth correlations within the shootapical meristem.