Geographic distribution of the V1016G knockdown resistance mutation in aedes albopictus. A warning bell for Europe

Background: Colonization of large part of Europe by the Asian tiger mosquito Aedes albopictus is causing autochthonous transmission of chikungunya and dengue exotic arboviruses. While pyrethroids are recommended only to reduce/limit transmission, they are widely implemented to reduce biting nuisance and to control agricultural pests, increasing the risk of insurgence of resistance mechanisms. Worryingly, pyrethroid resistance (with mortality < 70%) was recently reported in Ae. albopictus populations from Italy and Spain and associated with the V1016G point mutation in the voltage-sensitive sodium channel gene conferring knockdown resistance (kdr). Genotyping pyrethroid resistance-associated kdr mutations in field mosquito samples represents a powerful approach to detect early signs of resistance without the need for carrying out phenotypic bioassays which require availability of live mosquitoes, dedicated facilities and appropriate expertise.Methods: Here we report results on the PCR-genotyping of the V1016G mutation in 2530 Ae. albopictus specimens from 69 sampling sites in 19 European countries.Results: The mutation was identified in 12 sites from nine countries (with allele frequencies ranging from 1 to 8%), mostly distributed in two geographical clusters. The western cluster includes Mediterranean coastal sites from Italy, France and Malta as well as single sites from both Spain and Switzerland. The eastern cluster includes sites on both sides of the Black Sea in Bulgaria, Turkey and Georgia as well as one site from Romania. These results are consistent with genomic data showing high connectivity and close genetic relationship among West European populations and a major barrier to gene flow between West European and Balkan populations.Conclusions: The results of this first effort to map kdr mutations in Ae. albopictus on a continental scale show a widespread presence of the V1016G allele in Europe, although at lower frequencies than those previously reported from Italy. This represents a wake-up call for mosquito surveillance programs in Europe to include PCR-genotyping of pyrethroid resistance alleles, as well as phenotypic resistance assessments, in their routine activities

Feasibility, acceptability, and effectiveness of non-pharmaceutical interventions against infectious diseases among crisis-affected populations: a scoping review

BACKGROUND: Colonization of large part of Europe by the Asian tiger mosquito Aedes albopictus is causing autochthonous transmission of chikungunya and dengue exotic arboviruses. While pyrethroids are recommended only to reduce/limit transmission, they are widely implemented to reduce biting nuisance and to control agricultural pests, increasing the risk of insurgence of resistance mechanisms. Worryingly, pyrethroid resistance (with mortality < 70%) was recently reported in Ae. albopictus populations from Italy and Spain and associated with the V1016G point mutation in the voltage-sensitive sodium channel gene conferring knockdown resistance (kdr). Genotyping pyrethroid resistance-associated kdr mutations in field mosquito samples represents a powerful approach to detect early signs of resistance without the need for carrying out phenotypic bioassays which require availability of live mosquitoes, dedicated facilities and appropriate expertise. METHODS: Here we report results on the PCR-genotyping of the V1016G mutation in 2530 Ae. albopictus specimens from 69 sampling sites in 19 European countries. RESULTS: The mutation was identified in 12 sites from nine countries (with allele frequencies ranging from 1 to 8%), mostly distributed in two geographical clusters. The western cluster includes Mediterranean coastal sites from Italy, France and Malta as well as single sites from both Spain and Switzerland. The eastern cluster includes sites on both sides of the Black Sea in Bulgaria, Turkey and Georgia as well as one site from Romania. These results are consistent with genomic data showing high connectivity and close genetic relationship among West European populations and a major barrier to gene flow between West European and Balkan populations. CONCLUSIONS: The results of this first effort to map kdr mutations in Ae. albopictus on a continental scale show a widespread presence of the V1016G allele in Europe, although at lower frequencies than those previously reported from Italy. This represents a wake-up call for mosquito surveillance programs in Europe to include PCR-genotyping of pyrethroid resistance alleles, as well as phenotypic resistance assessments, in their routine activities

Involvement of the nuclear cap-binding protein complex in alternative splicing in Arabidopsis thaliana

The nuclear cap-binding protein complex (CBC) participates in 5′ splice site selection of introns that are proximal to the mRNA cap. However, it is not known whether CBC has a role in alternative splicing. Using an RT–PCR alternative splicing panel, we analysed 435 alternative splicing events in Arabidopsis thaliana genes, encoding mainly transcription factors, splicing factors and stress-related proteins. Splicing profiles were determined in wild type plants, the cbp20 and cbp80(abh1) single mutants and the cbp20/80 double mutant. The alternative splicing events included alternative 5′ and 3′ splice site selection, exon skipping and intron retention. Significant changes in the ratios of alternative splicing isoforms were found in 101 genes. Of these, 41% were common to all three CBC mutants and 15% were observed only in the double mutant. The cbp80(abh1) and cbp20/80 mutants had many more changes in alternative splicing in common than did cbp20 and cbp20/80 suggesting that CBP80 plays a more significant role in alternative splicing than CBP20, probably being a platform for interactions with other splicing factors. Cap-binding proteins and the CBC are therefore directly involved in alternative splicing of some Arabidopsis genes and in most cases influenced alternative splicing of the first intron, particularly at the 5′ splice site

Urine concentrations changes of cysteinyl leukotrienes in non-obese children with obstructive sleep apnea undergoing adenotonsillectomy

Objective: The main objective of the study was to compare preoperative to postoperative levels of urine-Cysteinyl leukotrienes (uCysLT) in children undergoing adenotonsillectomy (AT) for obstructive sleep apnea (OSA) in order to investigate whether exaggerated leukotriene activity is the cause or consequence of OSA. Methods and materials: A prospective study was conducted on non-obese children (4–10 years old) referred for overnight PSG. Children with moderate/severe OSA treated with AT were included. A second PSG study performed 2 months postoperatively to confirm OSA resolution, and those with residual OSA were excluded. Morning urine specimens after both PSG studies were obtained and pre-operative uCysLT levels were compared to postoperative levels. Results: 27 children fulfilled the criteria and underwent a post-operative PSG study with three exclusions for residual OSA (postop-AHI>2), so the study group consisted of 24 children (mean age: 5.7 ± 2.1 years). Mean preoperative and postoperative AHI was 10.96 ± 5.93 and 1.44 ± 0.56 respectively. Mean preop-uCysLT were 21.14 ± 4.65, while after AT they significantly reduced to 12.62 ± 2.67 (P < 0.01). Conclusion: uCysLT levels are significantly reduced after AT in non-obese children with moderate/severe OSA, suggesting that exaggerated leukotriene activity is mainly a consequence of OSA. © 2018 Elsevier B.V

Curcumin derivatives as potential mosquito larvicidal agents against two mosquito vectors, culex pipiens and aedes albopictus

Vector-borne diseases have appeared or re-emerged in many Southern Europe countries making the transmission of infectious diseases by mosquitoes (vectors) one of the greatest worldwide health threats. Larvicides have been used extensively for the control of Aedes (Stegomyia) albopictus (Skuse, 1895) (Diptera: Culicidae) and Culex pipiens Linnaeus, 1758 (Diptera: Culicidae) mosquitoes in urban and semi-urban environments, causing the increasing resistance of mosquitoes to commercial insecticides. In this study, 27 curcuminoids and monocarbonyl curcumin derivatives were synthesised and evaluated as potential larvicidal agents against Cx. pipiens and Ae. albopictus. Most of the compounds were more effective against larvae of both mosquito species. Four of the tested compounds, curcumin, demethoxycurcumin, curcumin-BF2 complex and a monocarbonyl tetramethoxy curcumin derivative exhibited high activity against both species. In Cx. pipiens the recorded LC50 values were 6.0, 9.4, 5.0 and 32.5 ppm, respectively, whereas in Ae. albopictus they exhibited LC50 values of 9.2, 36.0, 5.5 and 23.6 ppm, respectively. No conclusive structure activity relationship was evident from the results and the variety of descriptors values generated in silico provided some insight to this end. © 2021 by the authors. Licensee MDPI, Basel, Switzerland