New TRAP1 and Hsp90 chaperone inhibitors with cationic components: Preliminary studies on mitochondrial targeting.

TRAP1 (Hsp75) is the mitochondrial paralog of the Hsp90 molecular chaperone family. Due to structural similarity among Hsp90 chaperones, a potential strategy to induce apoptosis through mitochondrial TRAP1 ATPase inhibition has been envisaged and a series of compounds has been developed by binding the simple pharmacophoric core of known Hsp90 inhibitors with various appendages bearing a permanent cationic head, or a basic group highly ionizable at physiologic pH. Cationic appendages were selected as vehicles to deliver drugs to mitochondria. Indeed, masses of new derivatives were evidenced to accumulate in the mitochondrial fraction from colon carcinoma cells and a compound in the series, with a guanidine appendage, demonstrated good activity in inhibiting recombinant TRAP1 ATPase and cell growth and in inducing apoptotic cell death in colon carcinoma cells.

Rapid reconstitution of functionally active 6-sulfoLacNAc(+) dendritic cells (slanDCs) of donor origin following allogeneic haematopoietic stem cell transplant.

The role of dendritic cells (DCs) and macrophages in allogeneic haematopoietic stem cell transplant (HSCT) is critical in determining the extent of graft-versus-host response. The goal of this study was to analyse slanDCs, a subset of human proinflammatory DCs, in haematopoietic stem cell (HSC) sources, as well as to evaluate their 1-year kinetics of reconstitution, origin and functional capacities in peripheral blood (PB) and bone marrow (BM) of patients who have undergone HSCT, and their presence in graft-versus-host disease (GVHD) tissue specimens. slanDCs were also compared to myeloid (m)DCs, plasmacytoid (p)DCs and monocytes in HSC sources and in patients' PB and BM throughout reconstitution. slanDCs accounted for all HSC sources. In patients' PB and BM, slanDCs were identified from day +21, showing median frequencies comparable to healthy donors, donor origin and kinetics of recovery similar to mDCs, pDCs, and monocytes. Under cyclosporin treatment, slanDCs displayed a normal pattern of maturation, and maintained an efficient chemotactic activity and capacity of releasing tumour necrosis factor (TNF)-α upon lipopolysaccharide (LPS) stimulation. None the less, they were almost undetectable in GVHD tissue specimens, being present only in intestinal acute GVHD samples. slanDCs reconstitute early, being donor-derived and functionally competent. The absence of slanDCs from most of the GVHD-targeted tissue specimens seems to rule out the direct participation of these cells in the majority of the local reactions characterizing GVHD.

Swarming behaviour in natural populations of Anopheles gambiae and An. coluzzii: review of 4 years survey in rural areas of sympatry, Burkina Faso (West Africa).

The swarming behaviour of natural populations of Anopheles gambiae and An. coluzzii (formerly known as An. gambiae S and M forms, respectively) were investigated through longitudinal surveys conducted between July 2006 and October 2009 in two rural areas of south-western Burkina Faso where these forms are sympatric. In both sites, the majority of swarms were recorded above visual markers localised among houses. In Soumousso, a wooded area of savannah, 108 pairs caught in copula from 205 swarms were sampled; in VK7, a rice growing area, 491 couples from 250 swarms were sampled. If segregated swarms were the norm in both sites, many visual markers were shared by the two forms of An. gambiae. Furthermore, mixed swarms were collected annually in frequencies varying from one site to another, though no mixed inseminations were recorded, corroborating the low hybrid rate previously reported in the field. The occurrence of inter-specific mate-recognition mechanisms, which allow individuals to avoid hybridisation, is discussed.

Assortative mating in mixed swarms of the mosquito Anopheles gambiae s.s. M and S molecular forms, in Burkina Faso, West Africa.

The molecular form composition of Anopheles gambiae Giles s.s. (Diptera: Culicidae) mating swarms and the associated mating pairs (copulae) were investigated during two rainy seasons (July to October, 2005 and July to November, 2006) in the villages of Soumousso and Vallée du Kou (VK7). Although the habitats of these villages differ markedly, sympatric populations of M and S molecular forms of An. gambiae s.s. occur in both places periodically. The main aim was to assess the degree to which these molecular forms mate assortatively. In Soumousso, a wooded savannah habitat, the majority of swarm samples consisted of only S-form males (21/28), although a few M-form males were found in mixed M- and S-form swarms. In VK7, a rice growing area, the majority of swarm samples consisted of only M-form males (38/62), until October and November 2006, when there were nearly as many mixed-form as single-form swarms. Overall, ∼60% of M- and S-form swarms were temporally or spatially segregated; the two forms were effectively prevented from encountering each other. Of the remaining 40% of swarms, however, only about half were single-form and the rest were mixed-form. Of the 33 copulae collected from mixed-form swarms, only four were mixed-form pairs, significantly fewer than expected by random pairing between forms (χ(2) = 10.34, d.f. = 2, P < 0.01). Finally, all specimens of inseminated females were of the same form as the sperm contained within their spermatheca (n = 91), even for the four mixed-form copulae. These findings indicate that assortative mating occurs within mixed-form swarms, mediated most probably by close-range mate recognition cues.

SNP genotyping defines complex gene-flow boundaries among African malaria vector mosquitoes.

Mosquitoes in the Anopheles gambiae complex show rapid ecological and behavioral diversification, traits that promote malaria transmission and complicate vector control efforts. A high-density, genome-wide mosquito SNP-genotyping array allowed mapping of genomic differentiation between populations and species that exhibit varying levels of reproductive isolation. Regions near centromeres or within polymorphic inversions exhibited the greatest genetic divergence, but divergence was also observed elsewhere in the genomes. Signals of natural selection within populations were overrepresented among genomic regions that are differentiated between populations, implying that differentiation is often driven by population-specific selective events. Complex genomic differentiation among speciating vector mosquito populations implies that tools for genome-wide monitoring of population structure will prove useful for the advancement of malaria eradication.

Adjunctive brivaracetam for refractory partial-onset seizures: a randomized, controlled trial.

OBJECTIVE: To explore efficacy and safety/tolerability of adjunctive brivaracetam (BRV), a novel, high-affinity synaptic vesicle protein 2A ligand, which also inhibits neuronal voltage-dependent sodium channels, in patients with refractory partial-onset seizures (POS). METHODS: This was an exploratory, phase IIb, double-blind, randomized, parallel-group, placebo-controlled, dose-ranging study in patients 16-65 years with epilepsy experiencing > or =4 POS during 4-week baseline despite 1-2 concomitant antiepileptic drugs. Patients were randomized (1:1:1:1) to placebo, BRV 5 mg/day (BRV5), BRV 20 mg/day (BRV20), or BRV 50 mg/day (BRV50), administered BID without uptitration during a 7-week treatment period. Primary efficacy endpoint was POS frequency/week during the treatment period relative to placebo. RESULTS: A total of 208 patients constituted the intention-to-treat population; 197 completed the study. Estimated percentage reductions over placebo in POS frequency/week were 9.8% (BRV5; p = 0.240), 14.9% (BRV20; p = 0.062), and 22.1% (BRV50; p = 0.004). Median percent reductions from baseline in POS frequency/week were 21.7% (placebo), 29.9% (BRV5; p = 0.086), 42.6% (BRV20; p = 0.014), and 53.1% (BRV50; p < 0.001); > or =50% responder rates were 16.7% (placebo), 32.0% (BRV5; p = 0.047), 44.2% (BRV20; p = 0.002), and 55.8% (BRV50; p < 0.001); seizure freedom rates (POS) during the 7-week treatment period were 1.9% (placebo), 8.0% (BRV5; p = 0.193), 7.7% (BRV20; p = 0.193), and 7.7% (BRV50; p = 0.201). BRV was well-tolerated. Most adverse events were mild to moderate and occurred with similar incidence in placebo and BRV groups, and discontinuations due to treatment-emergent adverse events were infrequent (placebo 3.7%; BRV 2.6%). CONCLUSIONS: This interventional study provides preliminary Class I evidence that adjunctive BRV was efficacious and well-tolerated in patients aged 16-65 years with POS.

Towards a fuller understanding of mosquito behaviour: use of electrocuting grids to compare the odour-orientated responses of Anopheles arabiensis and An. quadriannulatus in the field.

The epidemiological role of and control options for any mosquito species depend on its degree of 'anthropophily'. However, the behavioural basis of this term is poorly understood. Accordingly, studies in Zimbabwe quantified the effects of natural odours from cattle and humans, and synthetic components of these odours, on the attraction, entry and landing responses of Anopheles arabiensis Giles (Diptera: Culicidae) and Anopheles quadriannulatus Theobald. The numbers of mosquitoes attracted to human or cattle odour were compared using electrocuting nets (E-nets), and entry responses were gauged by the catch from an odour-baited entry trap (OBET) relative to that from an odour-baited E-net. Landing responses were estimated by comparing the catches from E-nets and cloth targets covered with an electrocuting grid. For An. arabiensis, E-nets baited with odour from a single ox or a single man caught similar numbers, and increasing the dose of human odour from one to three men increased the catch four-fold. For An. quadriannulatus, catches from E-nets increased up to six-fold in the progression: man, three men, ox, and man + ox, with catch being correlated with bait mass. Entry responses of An. arabiensis were stronger with human odour (entry response 62%) than with ox odour (6%) or a mixture of cattle and human odours (15%). For An. quadriannulatus, the entry response was low (< 2%) with both cattle and human odour. Anopheles arabiensis did not exhibit a strong entry response to carbon dioxide (CO2) (0.2-2 L/min). The trends observed using OBETs and E-nets also applied to mosquitoes approaching and entering a hut. Catches from an electrocuting target baited with either CO2 or a blend of acetone, 1-octen-3-ol, 4-methylphenol and 3-n-propylphenol - components of natural ox odour - showed that virtually all mosquitoes arriving there alighted on it. The propensity of An. arabiensis to enter human habitation seemed to be mediated by odours other than CO2 alone. Characterizing 'anthropophily' by comparing the numbers of mosquitoes caught by traps baited with different host odours can lead to spurious conclusions; OBETs baited with human odour caught around two to four times more An. arabiensis than cattle-baited OBETs, whereas a human-baited E-net caught less ( approximately 0.7) An. arabiensis than a cattle-baited E-net. Similar caution is warranted for other species of mosquito vectors. A fuller understanding of how to exploit mosquito behaviour for control and surveys requires wider approaches and more use of appropriate tools.

Anopheles funestus (Diptera: Culicidae) in a humid savannah area of western Burkina Faso: bionomics, insecticide resistance status, and role in malaria transmission.

An entomological survey was carried out in three humid savannah sites of western Burkina Faso (Bama, Lena, and Soumousso) to (1) update the taxonomy of the Anopheles funestus Giles group, (2) examine the role of each species in malaria transmission, (3) characterize the insecticide resistance status of this malaria vector, and (4) determine the distribution of An. funestus chromosomal forms in these areas. Polymerase chain reaction identification of the members showed the occurrence of An. leesoni Evans in Lena and An. rivulorum-like in Soumousso in addition to An. funestus s.s. Malaria transmission was ensured mainly by An. funestus s.s. both in Soumousso and Lena and by An. gambiae s.s. Giles in Bama, the rice-growing area. The insecticide resistance status performed only on An. funestus indicated that this mosquito was susceptible to pyrethroids irrespective of the study area, but it was resistant to dieldrin. Furthermore, the occurrence of the two chromosomal forms of An. funestus, namely, Kiribina and Folonzo, seemed to follow ecological setups where Kiribina predominated in the irrigated area and Folonzo was more frequent in classic savannah. This study revealed that the problematic of An. funestus taxonomy was closer to that of An. gambiae requiring more structured studies to understand its genetic ecology.

Development of a novel sticky trap for container-breeding mosquitoes and evaluation of its sampling properties to monitor urban populations of Aedes albopictus.

Collection methods currently used for large-scale sampling of adult Stegomyia mosquitoes (Diptera: Culicidae) present several operational limitations, which constitute major drawbacks to the epidemiological surveillance of arboviruses, the evaluation of the impact of control strategies, and the surveillance of the spreading of allochthonous species into non-endemic regions. Here, we describe a new sticky trap designed to capture adult container-breeding mosquitoes and to monitor their population dynamics. We tested the sampling properties of the sticky trap in Rome, Italy, where Aedes (Stegomyia) albopictus is common. The results of our observations, and the comparison between sticky trap catches and catches made with the standard oviposition trap, are presented. The sticky trap collected significantly larger numbers of Ae. albopictus females than any other Culicidae species representing >90% of the total catches. A maximum of 83 An. albopictus females was collected in a single week. A high correlation (Pearson correlation coefficient r= 0.96) was found between the number of females and the number of eggs collected by the traps. The functional relationship between the number of eggs and the number of adult females was assessed by major axis regression fitted to log(1 +x)-transformed trap counts as y= 0.065 + 1.695x. Trap samples significantly departed from a random distribution; Taylor's power law was fitted to the trap samples to quantify the degree of aggregation in the catches, returning the equations s(2)= 2.401 m(1.325) for the sticky trap and s(2)= 13.068 m(1.441) for the ovitrap, with s(2) and m denoting the weekly catch variance and mean, respectively, indicating that eggs were significantly more aggregated than mosquitoes (P < 0.0001). Taylor's power law parameters were used to estimate the minimum number of sample units necessary to obtain sample estimates with a fixed degree of precision and sensitivity. For the range of densities encountered in our study area during the Ae. albopictus breeding season, the sticky trap was more precise and sensitive than the ovitrap. At low population densities (c. < 0.1 mosquito/trap), however, the ovitrap was more sensitive at detecting the presence of this species. Overall, our results indicate that our new model of sticky trap can be used to sample Ae. albopictus females in urban environments, and, possibly, other container-breeding Stegomyia mosquitoes (e.g. Aedes aegypti). The technical properties of the new trap are discussed with respect to its possible application in monitoring the population dynamics of container-breeding mosquitoes, in studying their bionomics, and in vector surveillance and, possibly, control.

Comparative analysis of epicuticular lipid profiles of sympatric and allopatric field populations of Anopheles gambiae s.s. molecular forms and An. arabiensis from Burkina Faso (West Africa).

We analysed by gas chromatography-mass spectrometry (GC-MS) and Gas Chromatography-Flame Ionization Detector (GC-FID) the epicuticular lipid profiles of field females of the major Afro-tropical malaria vector, Anopheles gambiae. The samples were collected in three villages in Burkina Faso (West Africa), where An. gambiae M and S molecular forms and An. arabiensis live sympatrically. The aim was to compare the cuticular hydrocarbon (CHC) composition of individual field specimens of these three taxa, to highlight possible differences among them. All the samples analysed by GC-MS (55 individuals and eight pools) were characterized by the same 48 CHCs and 10 oxygenated compounds. The 19 most abundant CHCs were quantified in 174 specimens by GC-FID: quantitative intra-taxon differences were found between allopatric populations of both An. arabiensis and S-form. Inter-taxa quantitative differences in the relative abundances of some hydrocarbons between pairs of sympatric taxa were also found, which appear to be mainly linked to local situations, with the possible exception of diMeC(35) between An. arabiensis and S-form. Moreover, MeC(29) shows some degree of differentiation between S- and M-form in all three villages. Possible causes of these differences are discussed.

Blood-feeding behaviour of the malarial mosquito Anopheles arabiensis: implications for vector control.

Feeding behaviour of the malaria vector Anopheles arabiensis Patton (Diptera: Culicidae) was monitored for 12 months (March 2003-February 2004) in the Konso District of southern Ethiopia (5 degrees 15'N, 37 degrees 28'E). More than 45 000 An. arabiensis females were collected by host-baited sampling methods (light-traps, human landing catches, cattle-baited traps) and from resting sites (huts and pit shelters). In the village of Fuchucha, where the ratio of cattle : humans was 0.6 : 1, 51% of outdoor-resting mosquitoes and 66% of those collected indoors had fed on humans, human baits outdoors caught > 2.5 times more mosquitoes than those indoors and the mean catch of mosquitoes from pit shelters was about five times that from huts. Overall, the vast majority of feeding and resting occurred outdoors. In the cattle camps of Konso, where humans slept outdoors close to their cattle, approximately 46% of resting mosquitoes collected outdoors had fed on humans despite the high cattle : human ratio (17 : 1). In both places, relatively high proportions of bloodmeals were mixed cow + human: 22-25% at Fuchucha and 37% in the cattle camps. Anthropophily was also gauged experimentally by comparing the numbers of mosquitoes caught in odour-baited entry traps baited with either human or cattle odour. The human-baited trap caught about five times as many mosquitoes as the cattle-baited one. Notwithstanding the potential pitfalls of using standard sampling devices to analyse mosquito behaviour, the results suggest that the An. arabiensis population is inherently anthropophagic, but this is counterbalanced by exophagic and postprandial exophilic tendencies. Consequently, the population feeds sufficiently on humans to transmit malaria (sporozoite rates: 0.3% for Plasmodium falciparum and 0.5% for P. vivax, by detection of circumsporozoite antigen) but also takes a high proportion of meals from non-human hosts, with 59-91% of resting mosquitoes containing blood from cattle. Hence, classical zooprophylaxis is unlikely to have a significant impact on the malaria vectorial capacity of An. arabiensis in Konso, whereas treating cattle with insecticide might do.

Chromosomal evidence of incipient speciation in the Afrotropical malaria mosquito Anopheles funestus.

The analysis of chromosomal polymorphism of paracentric inversions in anopheline mosquitoes has often been instrumental to the discovery of sibling species complexes and intraspecific genetic heterogeneities associated with incipient speciation processes. To investigate the population structure of Anopheles funestus Giles (Diptera: Culicidae), one of the three most important vectors of human malaria in sub-Saharan Africa, a three-year survey of chromosomal polymorphism was carried out on 4,638 karyotyped females collected indoors and outdoors from two villages of central Burkina Faso. Large and temporally stable departures from Hardy-Weinberg equilibrium due to significant deficits of heterokaryotypes were found irrespective of the place of capture, and of the spatial and temporal units chosen for the analysis. Significant linkage disequilibrium was observed among inversion systems on independently assorting chromosomal arms, indicating the existence of assortative mating phenomena. Results were consistent with the existence of two chromosomal forms characterized by contrasting degrees of inversion polymorphism maintained by limitations to gene flow. This hypothesis was supported by the reestablishment of Hardy-Weinberg and linkage equilibria when individual specimens were assigned to each chromosomal form according to two different algorithms. This pattern of chromosomal variability is suggestive of an incipient speciation process in An. funestus populations from Burkina Faso.

Rangewide population genetic structure of the African malaria vector Anopheles funestus.

Anopheles funestus is a primary vector of malaria in Africa south of the Sahara. We assessed its rangewide population genetic structure based on samples from 11 countries, using 10 physically mapped microsatellite loci, two per autosome arm and the X (N = 548), and 834 bp of the mitochondrial ND5 gene (N = 470). On the basis of microsatellite allele frequencies, we found three subdivisions: eastern (coastal Tanzania, Malawi, Mozambique and Madagascar), western (Burkina Faso, Mali, Nigeria and western Kenya), and central (Gabon, coastal Angola). A. funestus from the southwest of Uganda had affinities to all three subdivisions. Mitochondrial DNA (mtDNA) corroborated this structure, although mtDNA gene trees showed less resolution. The eastern subdivision had significantly lower diversity, similar to the pattern found in the codistributed malaria vector Anopheles gambiae. This suggests that both species have responded to common geographic and/or climatic constraints. The western division showed signatures of population expansion encompassing Kenya west of the Rift Valley through Burkina Faso and Mali. This pattern also bears similarity to A. gambiae, and may reflect a common response to expanding human populations following the development of agriculture. Due to the presumed recent population expansion, the correlation between genetic and geographic distance was weak. Mitochondrial DNA revealed further cryptic subdivision in A. funestus, not detected in the nuclear genome. Mozambique and Madagascar samples contained two mtDNA lineages, designated clade I and clade II, that were separated by two fixed differences and an average of 2% divergence, which implies that they have evolved independently for approximately 1 million years. Clade I was found in all 11 locations, whereas clade II was sampled only on Madagascar and Mozambique. We suggest that the latter clade may represent mtDNA capture by A. funestus, resulting from historical gene flow either among previously isolated and divergent populations or with a related species.

SINE insertion polymorphism on the X chromosome differentiates Anopheles gambiae molecular forms.

Polymorphic SINE insertions can be useful markers for assessing population structure and differentiation. Maque is a family of SINE elements which, based on bioinformatic analysis, was suggested to have been active recently in Anopheles gambiae, the major vector of malaria. Here, we report the development of polymorphic Maque insertions as population genetic markers in A. gambiae, and the use of these markers to better characterize divergence on the X chromosome between A. gambiae M and S molecular forms in populations from Burkina Faso and Mali. Our data are consistent with the recent activity of Maque. Phylogenetic analysis suggests that at least two recently active lineages may have a role in mediating genome evolution. We found differences in element insertion frequency and sequence between the M and S populations analysed. Significant differentiation was observed between these two groups across a 6 Mb region at the proximal (centromeric) end of the X chromosome. Locus-specific F(ST) values ranged from 0.14 to 1.00 in this region, yet were not significantly different from zero in more distal locations on the X chromosome; the trend was consistent in populations from both geographical locales suggesting that differentiation is not due to local adaptation. Strong differentiation between M and S at the proximal end of the X chromosome, but not outside this region, suggests the action of selection counteracting limited gene flow between these taxa and supports their characterization as incipient species.

Molecular differentiation between chromosomally defined incipient species of Anopheles funestus.

Anopheles funestus Giles is one of the most important vectors of malaria in sub-Saharan Africa. The population structure of this mosquito in Burkina Faso, West Africa based on chromosomal inversion data led to the description of two chromosomal forms, Kiribina and Folonzo. Because both forms co-occur in the same locales yet differ significantly, both in the frequency of inverted arrangements on chromosome arms 3R and 2R and in vectorial capacity, they were hypothesized to be emerging species with at least partial barriers to gene flow. This hypothesis would be strengthened by molecular evidence of differentiation between Kiribina and Folonzo at loci outside chromosomal inversions. We surveyed molecular variation in sympatric populations of the two forms using sequences from the mitochondrial ND5 gene and genotypes at sixteen microsatellite loci distributed across the genome. Both classes of marker revealed slight but significant differentiation between the two forms (mtDNA F(ST) = 0.023, P < 0.001; microsatellite F(ST) = 0.004, P < 0.001; R(st) = 0.009, P = 0.002). Locus-by-locus analysis of the microsatellite data showed that significant differentiation was not genome-wide, but could be attributed to five loci on chromosome 3R (F(ST) = 0.010, P < 0.001; R(st) = 0.016, P = 0.002). Importantly, three of these loci are outside of, and in linkage equilibrium with, chromosomal inversions, suggesting that differentiation between chromosomal forms extends beyond the inversions themselves. The slight overall degree of differentiation indicated by both marker classes is likely an underestimate because of recent population expansion inferred for both Folonzo and Kiribina. The molecular evidence from this study is consistent with the hypothesis of incipient speciation between Kiribina and Folonzo.

A microsatellite map of the African human malaria vector Anopheles funestus.

Microsatellite markers and chromosomal inversion polymorphisms are useful genetic markers for determining population structure in Anopheline mosquitoes. In Anopheles funestus (2N = 6), only chromosome arms 2R, 3R, and 3L are known to carry polymorphic inversions. The physical location of microsatellite markers with respect to polymorphic inversions is potentially important information for interpreting population genetic structure, yet none of the available marker sets have been physically mapped in this species. Accordingly, we mapped 32 polymorphic A. funestus microsatellite markers to the polytene chromosomes using fluorescent in situ hybridization (FISH) and identified 16 markers outside of known polymorphic inversions. Here we provide an integrated polytene chromosome map for A. funestus that includes the breakpoints of all known polymorphic inversions as well as the physical locations of microsatellite loci developed to date. Based on this map, we suggest a standard set of 16 polymorphic microsatellite markers that are distributed evenly across the chromosome complement, occur predominantly outside of inversions, and amplify reliably. Adoption of this set by researchers working in different regions of Africa will facilitate metapopulation analyses of this primary malaria vector.

[Aedes albopictus (Diptera: Culicidae) in Rome: experimental study of relevant control strategy parameters]. / Aedes albopictus (Diptera: Culicidae) a Roma: analisi sperimentale di parametri rilevanti in strategie di controllo.

Since 1997, Aedes albopictus has colonised and then rapidly invaded the city of Rome (Italy) and its peripheral areas. Presently, the control of this mosquito in Italy relies mainly on larvicidal treatment of street storm sewer catch basins with the organophosphate temephos. We have therefore obtained baseline data on the susceptibility to temephos of the Roman Ae. albopictus population by laboratory bioassays on F1 fourth-instar larvae following standard WHO protocols. Estimated lethal concentrations were 0.014 mg/l (LC50) and 0.022 mg/l (LC90) indicating a lack of resistance to this compound. The persistence of temephos in sewer catch basins was evaluated by follow-up of catch basins treated with a dose of 1.5 mg of active ingredient. Mosquito larvae were recovered in 10% and 50% of the treated basins at 9 and 18 days posttreatment, respectively. In order to understand the relative contribution of this larval habitat to adult populations, we conducted a survey in the Zoo of Rome to estimate the larval density of mosquitoes breeding in sewer catch basins. A complete census of a 16.5 ha area mapped 243 catch basins, but only 25 (10.3%) contained water; of the latter 8 (32.0%) hosted mosquito larvae. All positive catch basins contained larvae of Culex pipiens, which were associated with Culiseta longiareolata and/or Ae. albopictus in 6 and 3 cases, respectively. A longitudinal survey of one catch basin over 4 months showed that the mean larval density of Ae. albopictus was markedly lower than that of Cx pipiens and Cs. Iongiareolata, ranging between 0 and 1.3 larvae/dip as compared to 0-33.2 and 0-22.7 larvae/dip, respectively. However, adult densities of Ae. albopictus in this area estimated during the same period with 20 ovitraps showed consistently high values (proportion of positive ovitraps around 100%). These preliminary observations suggest that whenever alternative larval biotopes other than sewer catch basins are widely available, they might be more productive and/or preferred substrates to catch basins for Ae. albopictus breeding.

Ovicidal and larvicidal activity against Aedes aegypti and Anopheles gambiae complex mosquitoes of essential oils extracted from three spontaneous plants of Burkina Faso.

Essential oils extracted from dried leaves of three spontaneous plants naturally growing in Burkina Faso, i.e. Cymbopogon proximus, Lippia multiflora and Ocimum canum, exhibited larvicidal activity by the WHO standard protocol against 3rd and 4th instar F1-larvae of field-collected mosquitoes vectors of human disease, namely Aedes aegypti and members of the Anopheles gambiae complex, An. arabiensis and An. gambiae. The median lethal concentration (LC50) for Ae. aegypti and An. gambiae s.l. larvae ranged between 53.5-258.5 ppm and 61.9-301.6 ppm, respectively. The LC90 estimates ranged 74.8-334.8 ppm for Ae. aegypti, and 121.6-582.9 ppm for An. gambiae s.l. Ovicidal activity against eggs of An. gambiae s.l. was also demonstrated. The LC50 values for An. gambiae s.l. eggs ranged between 17.1-188.7 ppm, while LC90 values ranged between 33.5-488 ppm. Lippia multiflora showed the highest activity against An. gambiae s.l. eggs and Ae. aegypti larvae, whereas no difference was found among C. proximus and L. multiflora in their activity against An. gambiae s.l. larvae. Of the three plants, essential oils from O. canum had the lowest activity against both eggs and larvae. Eggs were more susceptible than larvae. Ae. aegypti larvae were more susceptible than larvae of An. gambiae s.l.

Speciation within Anopheles gambiae--the glass is half full.

Restrictions to gene flow among molecular forms of the mosquito Anopheles gambiae sensu stricto reveal an ongoing speciation process affecting the epidemiology of malaria in sub-Saharan Africa.

The bloodsucking arthropod bite as possible cofactor in the transmission of human herpesvirus-8 infection and in the expression of Kaposi's sarcoma disease.

Based on a review of the literature on human herpesvirus-8 (HHV8) and Kaposi's sarcoma (KS) and on the distribution of KS in Italy (Veneto region particularly), we hypothesize that the bite of bloodsucking arthropods is a cofactor in the seroconversion to HHV8 positivity and probably in the pathogenesis of KS. The bloodsucking arthropod releases with saliva powerful antihaemostatics and immunomodulators which may favour the replication and the establishment of the pathogen. Transmission would depend on the close contact of the child with a seropositive mother (or relatives) whose infective saliva is used to relieve itching and scratching at the arthropod bite's sites. During any deregulation of the immune system (e.g. ageing), local immune responses to new insect bites may induce virus activation which could prelude KS insurgence. The pathogen is not directly transmitted by the arthropod which merely prepares the cutaneous microenvironment for the virus. We have therefore introduced a new category of medically important arthropods, "promoter arthropods", besides those already defined as biological or mechanical vectors. Promoter arthropods are species able to induce in the host long-lasting, immediate or delayed-type hypersensitivity responses as well as local immunosuppression due to substances injected with their saliva. The striking variability of ORF-K1 gene of HHV8 could be due to the adaptation of the virus to the specific microenvironments resulting from the immune response to the salivary antigens characteristic of the bloodsucking arthropod species prevalent in each geographical area. It is worth noting that other viruses (especially Hepatitis B Virus) may exploit the same non-sexual transmission route.