Aedes albopictus bionomics data collection by citizen participation on Procida Island,a promising Mediterranean site for the assessment of innovative and community-based integrated pest management methods

In the last decades, the colonization of Mediterranean Europe and of other temperate regions by Aedes albopictus created an unprecedented nuisance problem in highly infested areas and new public health threats due to the vector competence of the species. The Sterile Insect Technique (SIT) and the Incompatible Insect Technique (IIT) are insecticide-free mosquito-control methods, relying on mass release of irradiated/manipulated males, able to complement existing and only partially effective control tools. The validation of these approaches in the field requires appropriate experimental settings, possibly isolated to avoid mosquito immigration from other infested areas, and preliminary ecological and entomological data. We carried out a 4-year study in the island of Procida (Gulf of Naples, Italy) in strict collaboration with local administrators and citizens to estimate the temporal dynamics, spatial distribution, and population size of Ae. albopictus and the dispersal and survival of irradiated males. We applied ovitrap monitoring, geo-spatial analyses, mark-release-recapture technique, and a citizen-science approach. Results allow to predict the seasonal (from April to October, with peaks of 928–9,757 males/ha) and spatial distribution of the species, highlighting the capacity of Ae. albopictus population of Procida to colonize and maintain high frequencies in urban as well as in sylvatic inhabited environments. Irradiated males shown limited ability to disperse (mean daily distance travelled <60m) and daily survival estimates ranging between 0.80 and 0.95. Overall, the ecological characteristics of the island, the acquired knowledge on Ae. albopictus spatial and temporal distribution, the high human and Ae. albopictus densities and the positive attitude of the resident population in being active parts in innovative mosquito control projects provide the ground for evidence-based planning of the interventions and for the assessment of their effectiveness. In addition, the results highlight the value of creating synergies between research groups, local administrators, and citizens for affordable monitoring (and, in the future, control) of mosquito populations.     

Serratia marcescens contains a heterodimeric HU protein like Escherichia coli and Salmonella typhimurium.

Homologs of the dimeric HU protein of Escherichia coli can be found in every prokaryotic organism that has been analyzed. In this work, we demonstrate that Serratia marcescens synthesizes two distinct HU subunits, like E. coli and Salmonella typhimurium, suggesting that the heterodimeric HU protein could be a common feature of enteric bacteria. A phylogenetic analysis of the HU-type proteins (HU and IHF) is presented, and a scheme for the origin of the hup genes and the onset of HU heterodimericity is suggested.     

Magnetic polarity fractions in magnetotactic bacterial populations near the geomagnetic equator

The relative numbers of North-seeking and South-seeking polarity types in natural populations of magnetotactic bacteria were determined at sites on the coast of Brazil. These sites were South of the geomagnetic equator and had upward geomagnetic inclinations of 1-12°. For upward inclinations >6°, South-seeking cells predominated over North-seeking cells by more than a factor of 10. For upward inclinations <6°, the fraction of North-seeking cells in the population increased with decreasing geomagnetic inclination, approaching 0.5 at the geomagnetic equator. We present a simple statistical model of a stochastic process that qualitatively accounts for the dynamics of the two polarity types in a magnetotactic bacterial population as a function of the geomagnetic field inclination.     

Sister-chromatid exchange rates in XX and XY cells of ten chimeric Callithrix jacchus individuals.

In order to ascertain whether or not sister-chromatid exchange (SCE) differs in relation to sex, SCE rates in XX and XY cells from 10 specimens of marmoset (Callithrix jacchus) were examined. The choice of this primate is particularly suitable for three reasons: most individuals have a chimeric constitution, the X chromosome is quite large and the Y chromosome is particularly small. Therefore, the influence of possible differences in their exposure to the external environment can be eliminated. The results obtained did not reveal any significant difference between SCE rates in male and female cells in any of the examined individuals.     

A Pyrosequencing assay for rapid recognition of SNPs in Mycobacterium tuberculosis embB306 region

Ethambutol (EMB) is in use worldwide as a first-line anti-tuberculosis drug and substitutions in codon 306 of the embB gene are the most common mutations found in EMB resistant Mycobacterium tuberculosis (MTB) strains. Pyrosequencing is a real time sequencing method able to rapidly detect mutations in a large number of samples. Using this technique we analyzed, in parallel with conventional sequencing, a 24 bp region of the embB gene of 28 MTB clinical isolates. Pyrosequencing efficiently identified all embB306 mutations, detecting three different single-base substitutions leading to 2 amino acid changes (Met to Val or Ile). Mutated embB alleles were detected in 2 multidrug-resistant (MDR) EMB-susceptible strains. Overall, our results demonstrated that the Pyrosequencing method efficiently recognizes mutations in embB in a very short time and represents a valid molecular method to detect mutations in the MTB embB306 region.     

Probing the cruzain S2 recognition subsite: a kinetic and binding energy calculation study

Cysteine proteases are relevant to several aspects of the parasite life cycle and the parasite-host relationship. Moreover, they appear as promising targets for antiparasite chemotherapy. Here, a quantitative investigation on the catalytic properties of cruzain, the papain-like cysteine protease from epimastigotes of Trypanosoma cruzi, is reported. The results indicate that kinetics for the cruzain catalyzed hydrolysis of N-alpha-benzyloxycarbonyl-l-arginyl-l-alanine-(7-amino-4-methylcoumarin), N-alpha-benzyloxycarbonyl-l-phenylalanyl-l-alanine-(7-amino-4-methylcoumarin), and N-alpha-benzyloxycarbonyl-l-tyrosyl-l-alanine-(7-amino-4-methylcoumarin) can be consistently fitted to the minimum three-step mechanism of cysteine proteases involving the acyl.enzyme intermediate E.P; the deacylation step is rate-limiting in enzyme catalysis. Remarkably, these substrates show identical catalytic parameters. This reflects the ability of the cruzain Glu205 residue, located at the bottom of the S(2) subsite, to neutralize the substrate/inhibitor polar P(2) residues (e.g., Arg or Tyr) and to be solvent-exposed when substrate/inhibitor nonpolar P(2) residues (e.g., Phe) fit the S(2) subsite. More complex catalytic mechanisms are also discussed. Binding free-energy calculation provides a quantitative framework for the interpretation of these results; in particular, direct evidence for the compensatory effect between Coulomb interaction(s) and solvation effect(s) is reported. These results appear of general significance for a deeper understanding of (macro)molecular recognition and for the rational design of novel inhibitors of parasitic cysteine proteases.     

Structure-affinity relationship studies on arylpiperazine derivatives related to quipazine as serotonin transporter ligands. Molecular basis of the selectivity SERT/5HT3 receptor

A series of quipazine derivatives, previously synthesized to probe the 5-HT(3) receptor, was evaluated for its potential interaction with serotonin transporter (SERT). Some of them show nanomolar affinity for the rodent SERT comparable to or slightly higher than quipazine or N-methylquipazine. Subsequently a candidate was selected on the basis of its SERT affinity and submitted to a molecular manipulation of the basic moiety. The structure-affinity relationships obtained provided information on the role of the fused benzene ring of quipazine in the interaction with the SERT binding site and on the stereoelectronic requirements for the interaction of both the heteroaromatic component and the basic moiety. Moreover, the comparison of the structure-affinity relationships obtained in the present work with those concerning the interaction of these heteroarylpiperazine derivatives with 5-HT3 receptor suggested some molecular determinants of the selectivity SERT/5HT3 receptor.     

Interpreting long-term changes in benthic community structure: a new protocol

Documentation of long-term change in benthic ecosystems is important for assessing and managing the effects of such change on: 1) secondary production, particularly leading to commercially important food webs, 2) pollutant transfer within the food web, 3) the ability of the new assemblage to metabolically burn-off labile detritus that might otherwise accumulate, contributing to long-term hypoxia, and 4) recyling of nutrients from the seafloor back to primary producers.Organism-sediment relationships which accompany benthic disturbances have predictable features. Although participating species may vary regionally or seasonally, their life-history attributes and functional relationships to the associated sediment appear to be universal. Pioneering seres are near-surface dwelling, productive, and are readily available to demersal predators. However, these taxa may be potential pollutant vectors. Dense tube mats may promote the deposition and retention of high BOD organic matter. Late successional stage seres are represented by deeply bioturbating head-down deposit feeders. The deep cryptic infaunal habitat of these species may make them less important as prey for epifaunal predators. Sediments populated by these equilibrium assemblages are characteristically low in labile organic matter, sedimentary sulphides, and oxygen demand. Nutrients (N, P, Si) are returned to primary producers by biogenic irrigation of sediment pore water.Mapping of successional mosaics is important for documenting major long-term change in benthic community structure and associated biogenic processes. Our mapping tool consists of a vessel-deployed sediment-profile camera; organism-sediment relationships can be imaged in situ with this instrument. Such a mapping protocol is not intended to replace traditional sampling. Rather, the successional maps are used to efficiently detect change in a system, design a cost-efficient sampling grid for obtaining geochemical and biological ground-truth samples, and to construct hypotheses about how the change might answer the four outlined management questions.