Diversity of the Bacterial and Viral Communities in the Tropical Horse Tick, Dermacentor nitens, in Colombia.

Ticks are obligatory hematophagous ectoparasites that transmit pathogens among various vertebrates, including humans. The microbial and viral communities of ticks, including pathogenic microorganisms, are known to be highly diverse. However, the factors driving this diversity are not well understood. The tropical horse tick, Dermacentor nitens, is distributed throughout the Americas and it is recognized as a natural vector of Babesia caballi and Theileria equi, the causal agents of equine piroplasmosis. In this study, we characterized the bacterial and viral communities associated with partially fed Dermacentor nitens females collected using a passive survey on horses from field sites representing three distinct geographical areas in the country of Colombia (Bolivar, Antioquia, and Cordoba). RNA-seq and sequencing of the V3 and V4 hypervariable regions of the 16S rRNA gene were performed using the Illumina-Miseq platform (Illumina, San Diego, CA, USA). A total of 356 operational taxonomic units (OTUs) were identified, in which the presumed endosymbiont, Francisellaceae/Francisella spp., was predominantly found. Nine contigs corresponding to six different viruses were identified in three viral families: Chuviridae, Rhabdoviridae, and Flaviviridae. Differences in the relative abundance of the microbial composition among the geographical regions were found to be independent of the presence of Francisella-like endosymbiont (FLE). The most prevalent bacteria found in each region were Corynebacterium in Bolivar, Staphylococcus in Antioquia, and Pseudomonas in Cordoba. Rickettsia-like endosymbionts, mainly recognized as the etiological agent of rickettsioses in Colombia, were detected in the Cordoba samples. Metatranscriptomics revealed 13 contigs containing FLE genes, suggesting a trend of regional differences. These findings suggest regional distinctions among the ticks and their bacterial compositions.

Integrated vector management program in the framework of the COVID-19 pandemic in Medellin, Colombia / El programa del manejo integrado de vectores en el marco de la pandemia por COVID-19 en Medellín, Colombia

Introduction: The COVID-19 pandemic pressured health care systems to remain alert and active in their vector-borne disease control and prevention programs, leading to changes in vector control strategies in urban areas affected by dengue, Zika and chikungunya. Objective: To describe the adaptations made to the vector control and surveillance program in Medellín during the COVID-19 health emergency. Materials and methods: Once the health emergency started, biosecurity protocols were developed. Entomological surveillance was strengthened from the institutional environment instead of homes. Data was collected in Medellín from 2018 to 2021 during the vector control and surveillance program activities, which included epidemiological and entomovirological surveillance, entomological index survey, ovitrap monitoring, community mobilization, search and elimination of mosquito breading sites, and chemical control. These actions were adapted and/or increased to promote self-care among communities in total and partial confinement, and to develop prevention and control measures. Results: Mosquito monitoring was increased by 40% using ovitraps, entomological virological surveillance showed an increase in 2020 of 34,4% compared to 2019 and virtual media was used to keep and improve contact with the community. Conclusion: The COVID-19 pandemic had a significant impact on arbovirus prevention and control programs. The city of Medellín quickly adapted its entomo-virological surveillance activities, control measures, and the contact with the community during the pandemic, which allow the Integrated Vector Management program to remain active in the city.

Introducción. La pandemia por COVID-19 presionó los sistemas de salud para mantener alerta y activos los programas de control y prevención de las enfermedades transmitidas por vectores, y generó cambios en las estrategias de control vectorial en áreas urbanas afectadas por el dengue, el Zika y el chikunguña. Objetivo. Describir las adaptaciones del programa de vigilancia y control de vectores en Medellín durante la contingencia sanitaria por COVID-19. Materiales y métodos. Iniciada la emergencia sanitaria, se elaboraron protocolos de bioseguridad. Se fortaleció la vigilancia entomológica institucional en lugar de las viviendas. La información se recolectó en Medellín durante los años 2018 a 2021, en las actividades del programa de vigilancia y control de vectores, que incluyen la vigilancia epidemiológica y entomo-virológica, el levantamiento de los índices entomológicos, el monitoreo de ovitrampas, la movilización social y comunitaria, la búsqueda y eliminación de criaderos, y el control químico; estas acciones se adaptarons o incrementaron para favorecer, de una parte, el autocuidado de las comunidades en confinamiento total y parcial, y de desarrollar las acciones de prevención y control. Resultados. Se incrementó en un 40 % la vigilancia del mosquito mediante ovitrampas, la vigilancia entomo-virológica presentó un incremento de 34,4 % en el 2020 respecto al 2019, y se utilizaron herramientas virtuales para mantener y mejorar el contacto con la comunidad. Conclusión. La pandemia por COVID-19 causó gran impacto en los programas de prevención y control de las enfermedades transmitidas por vectores. Medellín adaptó rápidamente las actividades de vigilancia entomo-virológica, las acciones de control y la comunicación con la comunidad durante la pandemia, y esto permitió mantener activo el programa del manejo integrado de vectores en la ciudad.

Diversity of the bacterial and viral communities in the tropical horse tick, Dermacentor nitens in Colombia.

Ticks are obligatory hematophagous ectoparasites that transmit pathogens among various vertebrates, including humans. The composition of the microbial and viral communities in addition to the pathogenic microorganisms is highly diverse in ticks, but the factors driving the diversity are not well understood. The tropical horse tick, Dermacentor nitens , is distributed throughout the Americas and it is recognized as a natural vector of Babesia caballi and Theileria equi , the causal agents of equine piroplasmosis. We characterized the bacterial and viral communities associated with partially-fed D. nitens females collected by a passive survey on horses from field sites representing three distinct geographical areas in Colombia (Bolivar, Antioquia, and Cordoba). RNA-seq and sequencing of the V3 and V4 hypervariable regions of the 16S rRNA gene were performed using the Illumina-Miseq platform. A total of 356 operational taxonomic units (OTUs) were identified, in which the presumed endosymbiotic Francisellaceae/ Francisella spp. was predominantly found. Nine contigs corresponding to six different viruses were identified in three viral families: Chuviridae, Rhabdoviridae, and Flaviviridae. Differences in the relative abundance of the microbial composition among the geographical regions were found to be independent of the presence of Francisella -Like Endosymbiont (FLE). The most prevalent bacteria found on each region were Corynebacterium in Bolivar, Staphylococcus in Antioquia, and Pseudomonas in Cordoba. Rickettsia -like endosymbionts, mainly recognized as the etiological agent of rickettsioses in Colombia were detected in the Cordoba samples. Metatranscriptomics revealed 13 contigs containing FLE genes, suggesting a trend of regional differences. These findings suggest regional distinctions among the ticks and their bacterial compositions.

El programa del manejo integrado de vectores en el marco de la pandemia por COVID-19 en Medellín, Colombia / Integrated vector management program in the framework of the COVID-19 pandemic in Medellin, Colombia

Introducción. La pandemia por COVID-19 presionó los sistemas de salud para mantener alerta y activos los programas de control y prevención de las enfermedades transmitidas por vectores, y generó cambios en las estrategias de control vectorial en áreas urbanas afectadas por el dengue, el Zika y el chikunguña. Objetivo. Describir las adaptaciones del programa de vigilancia y control de vectores en Medellín durante la contingencia sanitaria por COVID-19. Materiales y métodos. Iniciada la emergencia sanitaria, se elaboraron protocolos de bioseguridad. Se fortaleció la vigilancia entomológica institucional en lugar de las viviendas. La información se recolectó en Medellín durante los años 2018 a 2021, en las actividades del programa de vigilancia y control de vectores, que incluyen la vigilancia epidemiológica y entomo-virológica, el levantamiento de los índices entomológicos, el monitoreo de ovitrampas, la movilización social y comunitaria, la búsqueda y eliminación de criaderos, y el control químico; estas acciones se adaptarons o incrementaron para favorecer, de una parte, el autocuidado de las comunidades en confinamiento total y parcial, y de desarrollar las acciones de prevención y control. Resultados. Se incrementó en un 40 % la vigilancia del mosquito mediante ovitrampas, la vigilancia entomo-virológica presentó un incremento de 34,4 % en el 2020 respecto al 2019, y se utilizaron herramientas virtuales para mantener y mejorar el contacto con la comunidad. Conclusión. La pandemia por COVID-19 causó gran impacto en los programas de prevención y control de las enfermedades transmitidas por vectores. Medellín adaptó rápidamente las actividades de vigilancia entomo-virológica, las acciones de control y la comunicación con la comunidad durante la pandemia, y esto permitió mantener activo el programa del manejo integrado de vectores en la ciudad.

Introduction: The COVID-19 pandemic pressured health care systems to remain alert and active in their vector-borne disease control and prevention programs, leading to changes in vector control strategies in urban areas affected by dengue, Zika and chikungunya. Objective: To describe the adaptations made to the vector control and surveillance program in Medellín during the COVID-19 health emergency. Materials and methods: Once the health emergency started, biosecurity protocols were developed. Entomological surveillance was strengthened from the institutional environment instead of homes. Data was collected in Medellín from 2018 to 2021 during the vector control and surveillance program activities, which included epidemiological and entomo- virological surveillance, entomological index survey, ovitrap monitoring, community mobilization, search and elimination of mosquito breading sites, and chemical control. These actions were adapted and/or increased to promote self-care among communities in total and partial confinement, and to develop prevention and control measures. Results: Mosquito monitoring was increased by 40% using ovitraps, entomological- virological surveillance showed an increase in 2020 of 34,4% compared to 2019 and virtual media was used to keep and improve contact with the community. Conclusion: The COVID-19 pandemic had a significant impact on arbovirus prevention and control programs. The city of Medellín quickly adapted its entomo-virological surveillance activities, control measures, and the contact with the community during the pandemic, which allow the Integrated Vector Management program to remain active in the city.

Local-scale virome depiction in Medellín, Colombia, supports significant differences between Aedes aegypti and Aedes albopictus.

Aedes spp. comprise the primary group of mosquitoes that transmit arboviruses such as dengue, Zika, and chikungunya viruses to humans, and thus these insects pose a significant burden on public health worldwide. Advancements in next-generation sequencing and metagenomics have expanded our knowledge on the richness of RNA viruses harbored by arthropods such as Ae. aegypti and Ae. albopictus. Increasing evidence suggests that vector competence can be modified by the microbiome (comprising both bacteriome and virome) of mosquitoes present in endemic zones. Using an RNA-seq-based metataxonomic approach, this study determined the virome structure, Wolbachia presence and mitochondrial diversity of field-caught Ae. aegypti and Ae. albopictus mosquitoes in Medellín, Colombia, a municipality with a high incidence of mosquito-transmitted arboviruses. The two species are sympatric, but their core viromes differed considerably in richness, diversity, and abundance; although the community of viral species identified was large and complex, the viromes were dominated by few virus species. BLAST searches of assembled contigs suggested that at least 17 virus species (16 of which are insect-specific viruses [ISVs]) infect the Ae. aegypti population. Dengue virus 3 was detected in one sample and it was the only pathogenic virus detected. In Ae. albopictus, up to 11 ISVs and one plant virus were detected. Therefore, the virome composition appears to be species-specific. The bacterial endosymbiont Wolbachia was identified in all Ae. albopictus samples and in some Ae. aegypti samples collected after 2017. The presence of Wolbachia sp. in Ae. aegypti was not related to significant changes in the richness, diversity, or abundance of this mosquito's virome, although it was related to an increase in the abundance of Aedes aegypti To virus 2 (Metaviridae). The mitochondrial diversity of these mosquitoes suggested that the Ae. aegypti population underwent a change that started in the second half of 2017, which coincides with the release of Wolbachia-infected mosquitoes in Medellín, indicating that the population of wMel-infected mosquitoes released has introduced new alleles into the wild Ae. aegypti population of Medellín. However, additional studies are required on the dispersal speed and intergenerational stability of wMel in Medellín and nearby areas as well as on the introgression of genetic variants in the native mosquito population.

Blood Meals With Active and Heat-Inactivated Serum Modifies the Gene Expression and Microbiome of Aedes albopictus.

The Asian "tiger mosquito" Aedes albopictus is currently the most widely distributed disease-transmitting mosquito in the world. Its geographical expansion has also allowed the expansion of multiple arboviruses like dengue, Zika, and chikungunya, to higher latitudes. Due to the enormous risk to global public health caused by mosquitoes species vectors of human disease, and the challenges in slowing their expansion, it is necessary to develop new and environmentally friendly vector control strategies. Among these, host-associated microbiome-based strategies have emerged as promising options. In this study, we performed an RNA-seq analysis on dissected abdomens of Ae. albopictus females from Manhattan, KS, United States fed with sugar and human blood containing either normal or heat-inactivated serum, to evaluate the effect of heat inactivation on gene expression, the bacteriome transcripts and the RNA virome of this mosquito species. Our results showed at least 600 genes with modified expression profile when mosquitoes were fed with normal vs. heat-inactivated-containing blood. These genes were mainly involved in immunity, oxidative stress, lipid metabolism, and oogenesis. Also, we observed bacteriome changes with an increase in transcripts of Actinobacteria, Rhodospirillaceae, and Anaplasmataceae at 6 h post-feeding. We also found that feeding with normal blood seems to particularly influence Wolbachia metabolism, demonstrated by a significant increase in transcripts of this bacteria in mosquitoes fed with blood containing normal serum. However, no differences were observed in the virome core of this mosquito population. These results suggest that heat and further inactivation of complement proteins in human serum may have profound effect on mosquito and microbiome metabolism, which could influence interpretation of the pathogen-host interaction findings when using this type of reagents specially when measuring the effect of Wolbachia in vector competence.

Entomovirological Surveillance in Schools: Are They a Source for Arboviral Diseases Transmission?

Surveillance and control activities for virus-transmitting mosquitoes have primarily focused on dwellings. There is little information about viral circulation in heavily trafficked places such as schools. We collected and analyzed data to assess the presence and prevalence of dengue, chikungunya, and Zika viruses in mosquitoes, and measured Aedes indices in schools in Medellín (Colombia) between 2016-2018. In 43.27% of 2632 visits we collected Aedes adults, creating 883 pools analyzed by RT-PCR. 14.27% of pools yielded positive for dengue or Zika (infection rates of 1.75-296.29 for Aedes aegypti). Ae. aegypti was more abundant and had a higher infection rate for all studied diseases. Aedes indices varied over time. There was no association between Aedes abundance and mosquito infection rates, but the latter did correlate with cases of arboviral disease and climate. Results suggest schools are important sources of arbovirus and health agencies should include these sites in surveillance programs; it is essential to know the source for arboviral diseases transmission and the identification of the most population groups exposed to these diseases to research and developing new strategies.

Transcriptome of the Aedes aegypti Mosquito in Response to Human Complement Proteins.

Aedes aegypti is the primary mosquito vector of several human arboviruses, including the dengue virus (DENV). Vector control is the principal intervention to decrease the transmission of these viruses. The characterization of molecules involved in the mosquito physiological responses to blood-feeding may help identify novel targets useful in designing effective control strategies. In this study, we evaluated the in vivo effect of feeding adult female mosquitoes with human red blood cells reconstituted with either heat-inactivated (IB) or normal plasma (NB). The RNA-seq based transcript expression of IB and NB mosquitoes was compared against sugar-fed (SF) mosquitoes. In in vitro experiments, we treated Aag2 cells with a recombinant version of complement proteins (hC3 or hC5a) and compared transcript expression to untreated control cells after 24 h. The transcript expression analysis revealed that human complement proteins modulate approximately 2300 transcripts involved in multiple biological functions, including immunity. We also found 161 upregulated and 168 downregulated transcripts differentially expressed when human complement protein C3 (hC3) and human complement protein C5a (hC5a) treated cells were compared to the control untreated cells. We conclude that active human complement induces significant changes to the transcriptome of Ae. aegypti mosquitoes, which may influence the physiology of these arthropods.

Surveillance of Zika virus in field-caught Aedes aegypti and Aedes albopictus suggests important role of male mosquitoes in viral populations maintenance in Medellín, Colombia.

Due to the rapid spread of Zika virus (ZIKV) infection after its emergence in the Americas in 2015 and its relationship with birth defects, it became declared a Public Health Emergency of International Concern (WHO). The main mechanism by which this virus circulates in nature is horizontal transmission between vectors and humans. However, it has been suggested that vertical transmission (parent to offspring infection) or venereal mosquito-mosquito transmission may have an important role in viral populations maintenance during inter-epidemic periods. In this study we evaluate the presence of ZIKV in males and females of Aedes aegypti and Ae. albopictus in Medellín, Colombia, throughout the post-epidemic period of 2017 and 2018. A total of 7986 mosquitoes Aedes sp. resting within houses were captured and grouped in 2768 pools; 146 of these were RT-PCR positive for ZIKV, of which 38 (26%) were male mosquito pools (36 of Ae. aegypti and 2 of Ae. albopictus). The partial NS5 gene was sequenced in all ZIKV PCR-positive pools to confirm the ZIKV presence throughout spatial and temporal sampling. The results suggest a vector role of ZIKV by Ae. Albopictus; and because it is well known that male mosquitoes are not hematophagous, the high rate detection of ZIKV in male Aedes mosquitoes pools supports the existence of vertical or venereal transmission in Medellín, which can contribute to ZIKV maintenance during low transmission periods. This study provides a better understanding of the population dynamics of ZIKV in an endemic region during an inter-epidemic period and supports alternative transmission pathways as a mechanism to maintain endemism of this arbovirus.

New species and new distributional records of Neotropical Mantispidae (Insecta: Neuroptera).

The Neotropical fauna of Mantispidae is currently composed of 106 species. We provide new distributional records of Mantispidae from Colombia and Panama. Three new species are described, one in Symphrasinae from Colombia, and two in Mantispinae from Colombia and Panama. Haematomantispa nubeculosa (Navás, 1933) and Leptomantispa axillaris (Navás, 1908) are reported from Colombia for the first time, the former being the first record of the genus in the country. New locality records for other species previously known from Colombia are also given. For Panama, we report Anchieta fasciatella (Westwood, 1867) and Trichoscelia iridella (Westwood, 1867) for the first time, the former is herein newly transferred from Plega to Anchieta. Three names Mantispa confluens Navás, 1914, n. syn., Buyda apicata Navás, 1926, n. syn., and Mantispa neotropica Navás, 1933, n. syn., are here synonymized with Buyda phthisica (Gerstaecker, 1885). Updated keys for the genera of Mantispinae, and species of genera Trichoscelia, Buyda, and Climaciella from Colombia are included. With this new information, the known species richness of Mantispidae from Colombia increases from 21 to 26, and from 16 to 19 species in Panama.