Vector-virus interactions in vesicular stomatitis virus transmission by Culicoides sonorensis midges

Doctor of PhilosophyDepartment of EntomologyYoonseong ParkCulicoides biting midges are nuisance pests of livestock and well-known vectors of veterinary arboviruses, such as vesicular stomatitis virus (VSV). Due to the complex virus epidemiology, some of the mechanisms of geographic spread and virus maintenance during interepidemic periods remain unclear. To provide a foundation for the study of Culicoides-VSV interactions, C. sonorensis behavior, fitness related-traits, and patterns of viral infection were examined under various conditions. The research presented in this thesis shows that midges may become infected after ingesting blood meals (BM) containing doses as low as one infectious VSV particle per meal. Moreover, midge preference to feed on warmer BM at their first feeding may be an advantage for virus acquisition. Subsequent transmission can be efficiently achieved independent of the host body temperature without significantly impacting the vectors fitness. Likewise, ingestion of VSV in their first BM allows midges to ingest additional non-infectious meals, producing an infection enhancement and favoring transmission. After blood-feeding, most midges prefer to rest in areas with mild temperature, which maximizes their fitness and vectorial capacity. Investigating why some viruses spread from endemic regions to cause outbreaks in the U.S., results show that small genetic changes found in epidemic VSV lineages that appear to be related to host virulence also favor Culicoides vector competence. Lastly, this research show that female and male midges can venereally transmit VSV at significantly high rates, suggesting VSV maintenance in vector populations. This was the first demonstration of venereal transmission for VSV and for any of the viruses Culicoides midges transmit. This cumulative body of research highlights the epidemiological implications of vector behavior and physiology on VSV infection dynamics and provides fundamental knowledge in VSV transmission and maintenance mechanisms by C. sonorensis during outbreaks in the U.S

Elaboración de la segunda fase del manual de interventoría para la instalación, reemplazo y rehabilitación de infraestructura subterránea mediante el uso de tecnologías sin zanja

El trabajo de grado denominado Elaboración de la segunda fase del manual de interventoría para instalación, reemplazo y rehabilitación de infraestructura subterránea mediante el uso de tecnologías sin zanja señala los aspectos generales de la interventoría y describe las tecnologías sin zanja conocidas como: Auger Boring, Impact Moling y Pipe Ramming y explica detalladamente como se debe hacer la interventoría técnica de estas tecnologías, es decir el marco normativo para cada una de ellas y los criterios de aceptación que deben tenerse en cuenta por parte de la entidad que haga la interventoría. En la monografía también se hace el análisis de casos de estudio donde se hayan aplicado las tecnologías trabajadas y se hace una retroalimentación de estos casos, finalizando asi con unas conclusiones generales de lo que se encontró mientras se elaboraba la tesis.It s the recollection of the general aspects of the auditing process and the description of the trenchless technologies known as Auger Boring, Impact Moling and Pipe Ramming. Explaining how the technical supervision is done, focused on the regulatory framework and the acceptable criteria to be taken into account by the entity making the auditing. Making conclusion based on the analysis of real cases from where the feedback is used to elaborate a guide to follow when applying this technology.Ingeniero (a) CivilPregrad

Serosurvey of human antibodies recognizing Aedes aegypti D7 salivary proteins in Colombia

Citation: Londono-Renteria, B. L., Shakeri, H., Rozo-Lopez, P., Conway, M. J., Duggan, N., Jaberi-Douraki, M., & Colpitts, T. M. (2018). Serosurvey of Human Antibodies Recognizing Aedes aegypti D7 Salivary Proteins in Colombia. Frontiers in Public Health, 6. https://doi.org/10.3389/fpubh.2018.00111Background: Dengue is one of the most geographically significant mosquito-borne viral diseases transmitted by Aedes mosquitoes. During blood feeding, the mosquito deposits salivary proteins that induce antibody responses. These can be related to the intensity of exposure to bites. Some mosquito salivary proteins, such as D7 proteins, are known as potent allergens. The antibody response to D7 proteins can be used as a marker to evaluate the risk of exposure and disease transmission, and provide critical information for understanding the dynamics of vector-host interactions. Methods: The study was conducted at the Los Patios Hospital, Cucuta, Norte de Santander, Colombia. A total of 63 participants were enrolled in the study. Participants were categorized into three disease status groups, age groups, and socioeconomic strata. The level of IgG antibodies against D7 Aedes proteins was determined by ELISA. We used a statistical approach to determine if there is an association between antibody levels and factors such as age, living conditions, and dengue virus infection. Results: We found that IgG antibodies against D7 proteins were higher in non-DENV infected individuals in comparison to DENV-infected participants. Also, age factor showed a significant positive correlation with IgG antibodies against D7 proteins, and the living conditions (socioeconomic stratification), in people ages 20 years or older, are a statistically significant factor in the variability of IgG antibodies against D7 proteins. Conclusions: This pilot study represents the first approximation to elucidate any correlation between the antibody response against mosquito D7 salivary proteins and its correlation with age, living conditions and dengue virus infection in a dengue endemic area

Impacts of Infectious Dose, Feeding Behavior, and Age of Culicoides sonorensis Biting Midges on Infection Dynamics of Vesicular Stomatitis Virus

Culicoides sonorensis biting midges are biological vectors of vesicular stomatitis virus (VSV) in the U.S. Yet, little is known regarding the amount of ingested virus required to infect midges, nor how their feeding behavior or age affects viral replication and vector competence. We determined the minimum infectious dose of VSV-New Jersey for C. sonorensis midges and examined the effects of multiple blood-feeding cycles and age at the time of virus acquisition on infection dynamics. A minimum dose of 3.2 logs of virus/mL of blood resulted in midgut infections, and 5.2 logs/mL resulted in a disseminated infection to salivary glands. For blood-feeding behavior studies, ingestion of one or two non-infectious blood meals (BM) after a VSV infectious blood meal (VSV-BM) resulted in higher whole-body virus titers than midges receiving only the single infectious VSV-BM. Interestingly, this infection enhancement was not seen when a non-infectious BM preceded the infectious VSV-BM. Lastly, increased midge age at the time of infection correlated to increased whole-body virus titers. This research highlights the epidemiological implications of infectious doses, vector feeding behaviors, and vector age on VSV infection dynamics to estimate the risk of transmission by Culicoides midges more precisely

Mosquito species (Diptera, Culicidae) in three ecosystems from the Colombian Andes: identification through DNA barcoding and adult morphology

Colombia, one of the world’s megadiverse countries, has a highly diverse mosquito fauna and a high prevalence of mosquito-borne diseases. In order to provide relevant information about the diversity and taxonomy of mosquito species in Colombia and to test the usefulness of DNA barcodes, mosquito species collected at different elevations in the departments of Antioquia and Caldas were identified combining adult morphology and barcode sequences. A total of 22 mosquito species from eight genera were identified using these combined techniques. We generated 77 barcode sequences with 16 species submitted as new country records for public databases. We examined the usefulness of DNA barcodes to discriminate mosquito species from the Neotropics by compiling 1,292 sequences from a total of 133 species and using the tree-based methods of neighbor-joining and maximum likelihood. Both methodologies provided similar results by resolving 105 species of mosquitoes separated into distinct clusters. This study shows the importance of combining classic morphological methodologies with molecular tools to accurately identify mosquitoes from Colombia

Updated list of the mosquitoes of Colombia (Diptera: Culicidae)

A revised list of the mosquitoes (Diptera: Culicidae) known to occur in Colombia is presented. A total of 324 species from 28 genera of Culicidae are included. The species names are organized in alphabetical order according to the current generic and subgeneric classification, along with their authorship. The list is compiled in order to support mosquito research in Colombia. Our systematic review and literature survey found, by 16 February 2015, 13 records of culicid species previously overlooked by mosquito catalogs for Colombia: Anopheles costai da Fonseca & da Silva Ramos, 1939, An. fluminensis Root, 1927, An. malefactor Dyar & Knab, 1907, An. shannoni Davis, 1931, An. vargasi Galbadón, Cova García & Lopez, 1941, Culex mesodenticulatus Galindo & Mendez, 1961, Haemagogus capricornii Lutz, 1904, Isostomyia espini (Martini, 1914), Johnbelkinia leucopus (Dyar & Knab, 1906), Mansonia indubitans Dyar & Shannon, 1925, Psorophora saeva Dyar & Knab, 1906, Sabethes glaucodaemon (Dyar & Shannon, 1925), and Wyeomyia intonca Dyar & Knab, 1909. Moreover, Wyeomyia (Dendromyia) luteoventralis Theobald, 1901 is recorded for Colombia for the first time. This work provides important insights into mosquito diversity in Colombia, using the current nomenclature and phylogenetic rankings

Effect of Constant Temperatures on Culicoides sonorensis Midge Physiology and Vesicular Stomatitis Virus Infection

Culicoides midges play an important role in vesicular stomatitis virus (VSV) transmission to US livestock. After VSV-blood feeding, blood digestion followed by oviposition occurs while ingested virus particles replicate and disseminate to salivary glands for transmission during subsequent blood-feeding events. Changes to environmental temperature may alter the feeding–oviposition–refeeding cycles, midge survival, VSV infection, and overall vector capacity. However, the heterothermic midge may respond rapidly to environmental changes by adjusting their thermal behavior to resting in areas closer to their physiological range. Here we investigated the effects of four constant environmental temperatures (20, 25, 30, and 35 °C) on C. sonorensis survival, oviposition, and VSV infection, as well as resting thermal preferences after blood-feeding. We found that most midges preferred to rest in areas at 25–30 °C. These two constant temperatures (25 and 30 °C) allowed an intermediate fitness performance, with a 66% survival probability by day 10 and oviposition cycles occurring every 2–3 days. Additionally, VSV infection rates in bodies and heads with salivary glands were higher than in midges held at 20 °C and 35 °C. Our results provide insight into the implications of temperature on VSV–Culicoides interactions and confirm that the range of temperature preferred by midges can benefit both the vector and the arbovirus

Vesicular Stomatitis Virus Transmission: A Comparison of Incriminated Vectors

Vesicular stomatitis (VS) is a viral disease of veterinary importance, enzootic in tropical and subtropical regions of the Americas. In the U.S., VS produces devastating economic losses, particularly in the southwestern states where the outbreaks display an occurrence pattern of 10-year intervals. To date, the mechanisms of the geographic spread and maintenance cycles during epizootics remain unclear. This is due, in part, to the fact that VS epidemiology has a complex of variables to consider, including a broad range of vertebrate hosts, multiple routes of transmission, and an extensive diversity of suspected vector species acting as both mechanical and biological vectors. Infection and viral progression within vector species are highly influenced by virus serotype, as well as environmental factors, including temperature and seasonality; however, the mechanisms of viral transmission, including non-conventional pathways, are yet to be fully studied. Here, we review VS epidemiology and transmission mechanisms, with comparisons of transmission evidence for the four most incriminated hematophagous dipteran taxa: Aedes mosquitoes, Lutzomyia sand flies, Simulium black flies, and Culicoides biting midges

Venereal Transmission of Vesicular Stomatitis Virus by Culicoides sonorensis Midges

Culicoides sonorensis biting midges are well-known agricultural pests and transmission vectors of arboviruses such as vesicular stomatitis virus (VSV). The epidemiology of VSV is complex and encompasses a broad range of vertebrate hosts, multiple routes of transmission, and diverse vector species. In temperate regions, viruses can overwinter in the absence of infected animals through unknown mechanisms, to reoccur the next year. Non-conventional routes for VSV vector transmission may help explain viral maintenance in midge populations during inter-epidemic periods and times of adverse conditions for bite transmission. In this study, we examined whether VSV could be transmitted venereally between male and female midges. Our results showed that VSV-infected females could venereally transmit virus to uninfected naïve males at a rate as high as 76.3% (RT-qPCR), 31.6% (virus isolation) during the third gonotrophic cycle. Additionally, VSV-infected males could venereally transmit virus to uninfected naïve females at a rate as high as 76.6% (RT-qPCR), 49.2% (virus isolation). Immunofluorescent staining of micro-dissected reproductive organs, immunochemical staining of midge histological sections, examination of internal reproductive organ morphology, and observations of mating behaviors were used to determine relevant anatomical sites for virus location and to hypothesize the potential mechanism for VSV transmission in C. sonorensis midges through copulation

Behavioral factors associated with the pathological use of video games in young university students

Jugar videojuegos se ha convertido en una actividad de ocio cada vez más recurrente en la sociedad, y su importante crecimiento dentro de la población joven es un tema que podría ser de preocupación para el cuidado de la salud. Hasta los años más recientes se ha empezado a tener en cuenta la gravedad de los efectos negativos que puede acarrear la adicción a los videojuegos en el bienestar de una persona. El presente trabajo pretende identificar los factores de riesgo y conductas asociadas al uso patológico de videojuegos en estudiantes universitarios. El diseño de investigación empleado fue no experimental transversal y correlacional, donde la muestra de participantes fue de N = 208 que comprendió estudiantes universitarios entre las edades de 17 y 34 años. Se construyó e implementó una escala tipo Likert compuesta por 51 ítems con cinco categorías: Estado de ánimo, Hábitos, Síntomas, Habilidades intrapersonales, y Habilidades Interpersonales. En los resultados se encontró que el género masculino presenta una mayor predisposición a desarrollar conductas adictivas frente al uso de videojuegos en tanto que, sus habilidades intrapersonales se presentan como un factor de riesgo. Asimismo, se encontraron relaciones entre el tipo de institución al cual pertenecían los estudiantes y la calidad de sus habilidades intrapersonales. Y, por otro lado, se pudo establecer una relación entre la edad y la sintomatología de uso patológico.Playing video games has become an increasingly recurrent leisure activity in society, and its significant growth within the young population is an issue that could be of concern for health care. It is only in recent years that the seriousness of the negative effects that video game addiction can have on a person's well-being has begun to be considered. The present study aims to identify the risk factors and behaviours associated with the pathological use of video games in university students. The research design employed was non-experimental, cross-sectional, and correlational, where the sample of participants was N = 208, comprising university students between the ages of 17 and 34 years. A Likert-type scale composed of 51 items with five categories: Mood, Habits, Symptoms, Intrapersonal Skills, and Interpersonal Skills was constructed and implemented. In the results it was found that the male gender presents a greater predisposition to develop addictive behaviours when playing video games, while their intrapersonal skills are presented as a risk factor. Likewise, relationships were found between the type of institution to which the students belonged and the quality of their intrapersonal skills. On the other hand, it was possible to establish a relationship between age and the symptoms of pathological use.Psicólogo (a)Pregrad