Common Bed Bugs: Non-Viable Hosts for Parasites.

The hemoflagellate parasite is transmitted by triatomine kissing bugs and may co-infect humans together with its Chagas disease-causing congener . Using real-time quantitative polymerase chain reaction (RT-qPCR) and antimicrobial assays, we studied () the temporal and spatial distribution of in common bed bugs, , following oral ingestion and hemocoelic injection of and () the immune responses of bed bugs induced by infections. Irrespective of infection mode, no live were present in the bed bugs' hemolymph, salivary glands, or feces.

Multigenerational expression of antimicrobial peptides in Aedes aegypti exposed to Metarhizium anisopliae: Is trans-generational immune priming involved?

We assessed, for the first time, a multigenerational expression of antimicrobial peptides (AMPs) in Aedes aegypti larvae exposed to the entomopathogenic fungus, Metarhizium anisopliae, and correlated it with a possible involvement in trans-generational immune priming (TGIP). Aedes aegypti larvae were first exposed to blastospores or conidia of M. anisopliae CG 489 for 24 and 48 h, and the relative expression of AMPs were measured using quantitative Real-Time PCR.

A novel prolixicin identified in common bed bugs with activity against both bacteria and parasites.

The hematophagous common bed bug, Cimex lectularius, is not known to transmit human pathogens outside laboratory settings, having evolved various immune defense mechanisms including the expression of antimicrobial peptides (AMPs). We unveil three novel prolixicin AMPs in bed bugs, exhibiting strong homology to the prolixicin of kissing bugs, Rhodnius prolixus, and to diptericin/attacin AMPs. We demonstrate for the first time sex-specific and immune mode-specific upregulation of these prolixicins in immune organs, the midgut and rest of body, following injection and ingestion of Gr+ (Bacillus subtilis) and Gr- (Escherichia coli) bacteria.

Activation of immune pathways in common bed bugs, , in response to bacterial immune challenges - a transcriptomics analysis.

The common bed bug, , is an urban pest of global health significance, severely affecting the physical and mental health of humans. In contrast to most other blood-feeding arthropods, bed bugs are not major vectors of pathogens, but the underlying mechanisms for this phenomenon are largely unexplored. Here, we present the first transcriptomics study of bed bugs in response to immune challenges.

Profiling lipidomic changes in dengue-resistant and dengue-susceptible strains of Colombian Aedes aegypti after dengue virus challenge.

The mosquito Aedes aegypti is the primary vector for all four serotypes of dengue viruses (DENV1-4), which infect millions across the globe each year. Traditional insecticide programs have been transiently effective at minimizing cases; however, insecticide resistance and habitat expansion have caused cases of DENV to surge over the last decade. There is an urgent need to develop novel vector control measures, but these are contingent on a detailed understanding of host-parasite interactions.

A Novel Model of Pathogenesis of Propagules through the Midguts of Larvae.

We assessed the effect of the entomopathogenic fungus against . Conidia of strains CG 489, CG 153, and IBCB 481 were grown in Adamek medium under different conditions to improve blastospore production. Mosquito larvae were exposed to blastospores or conidia of the three fungal strains at 1 × 10 propagules mL.

Beauveria bassiana interacts with gut and hemocytes to manipulate Aedes aegypti immunity.

Background: Mosquito-borne diseases affect millions of people. Chemical insecticides are currently employed against mosquitoes. However, many cases of insecticide resistance have been reported.

Characterization of New Defensin Antimicrobial Peptides and Their Expression in Bed Bugs in Response to Bacterial Ingestion and Injection.

Common bed bugs, , can carry, but do not transmit, pathogens to the vertebrate hosts on which they feed. Some components of the innate immune system of bed bugs, such as antimicrobial peptides (AMPs), eliminate the pathogens. Here, we determined the molecular characteristics, structural properties, and phylogenetic relatedness of two new defensins (CL-defensin1 (XP_024085718.

A fat body transcriptome analysis of the immune responses of Rhodnius prolixus to artificial infections with bacteria.

Background: Rhodnius prolixus is an important vector of Trypanosoma cruzi, the causal agent of Chagas disease in humans. Despite the medical importance of this and other triatomine vectors, the study of their immune responses has been limited to a few molecular pathways and processes. Insect immunity studies were first described for holometabolous insects such as Drosophila melanogaster, and it was assumed that their immune responses were conserved in all insects.

Time- and tissue-specific antimicrobial activity of the common bed bug in response to blood feeding and immune activation by bacterial injection.

Unlike almost all hematophagous insects, common bed bugs, Cimex lectularius, are not known to transmit pathogens to humans. To help unravel the reasons for their lack of vector competence, we studied the time- and tissue-dependent expression of innate immune factors after blood feeding or immune activation through the intrathoracic injection of bacteria. We used minimum inhibitory concentration (MIC) bioassays and the Kirby-Bauer protocol to evaluate antimicrobial peptide (AMP) activity in tissue extracts from the midguts or 'rest of body' (RoB) tissues (containing hemolymph and fat body AMPs) against Gram-positive and Gram-negative bacteria.

Evolutionary history of orangutan plasmodia revealed by phylogenetic analysis of complete mtDNA genomes and new biogeographical divergence dating calibration models.

During the past 15 years, researchers have shown a renewed interest in the study of the Plasmodium parasites that infect orangutans. Most recently, studies examined the phylogenetic relationships and divergence dates of these parasites in orangutans using complete mitochondrial DNA genomes. Questions regarding the dating of these parasites, however, remain.

Transcriptome comparison of dengue-susceptible and -resistant field derived strains of Colombian Aedes aegypti using RNA-sequencing.

Background: Forty percent of the world's population live in areas where they are at risk from dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. Dengue viruses are transmitted primarily by the mosquito Aedes aegypti. In Cali, Colombia, approximately 30% of field collected Ae.

Nectar-dwelling microbes of common tansy are attractive to its mosquito pollinator, Culex pipiens L.

Background: There is widespread interkingdom signalling between insects and microbes. For example, microbes found in floral nectar may modify its nutritional composition and produce odorants that alter the floral odor bouquet which may attract insect pollinators. Mosquitoes consume nectar and can pollinate flowers.

uses the peptidoglycan recognition receptor rpPGRP-LC/LA to detect Gram-negative bacteria and activate the IMD pathway.

Insects rely on an innate immune system to recognize and eliminate pathogens. Key components of this system are highly conserved across all invertebrates. To detect pathogens, insects use Pattern recognition receptors (PRRs) that bind to signature motifs on the surface of pathogens called Pathogen Associated Molecular Patterns (PAMPs).

Antifungal immune responses in mosquitoes (Diptera: Culicidae): A review.

Mosquitoes transmit many parasites and pathogens to humans that cause significant morbidity and mortality. As such, we are constantly looking for new methods to reduce mosquito populations, including the use of effective biological controls. Entomopathogenic fungi are excellent candidate biocontrol agents to control mosquitoes.

Molecular relationships of introduced Aedes japonicus (Diptera: Culicidae) populations in British Columbia, Canada using mitochondrial DNA.

Aedes japonicus japonicus (Theobald) is a relatively recent immigrant to the Pacific Northwest, having been collected in Washington State in 2001 and in British Columbia (BC) since 2014. We applied a molecular barcoding approach to determine the phylogenetic relationship of Ae. j.

The Role of Bacterial Symbionts in Triatomines: An Evolutionary Perspective.

Insects have established mutualistic symbiotic interactions with microorganisms that are beneficial to both host and symbiont. Many insects have exploited these symbioses to diversify and expand their ecological ranges. In the Hemiptera (i.

The Midgut Microbiota of Colombian Populations with Different Levels of Resistance to the Insecticide Lambda-cyhalothrin.

Insecticide resistance in populations is a problem that hinders vector control and dengue prevention programs. In this study, we determined the susceptibility of populations from six Colombian regions to the pyrethroid lambda-cyhalothrin and evaluated the presence of the V1016I mutation in the sodium channel gene, which has been broadly involved in the resistance to this insecticide. The diversity of the gut microbiota of these mosquito populations was also analyzed.

The impact of baculovirus challenge on immunity: The effect of dose and time after infection.

Understanding how hosts respond to pathogen attack is crucial to disease management. The response of a host can be particularly important if hosts have to defend against multiple pathogens which could either benefit from or be suppressed by prior pathogen exposure. Insect defence against viruses is less well understood than responses to other entomopathogens and much of the information available relates to in vitro studies and model systems.

The innate immune system of kissing bugs, vectors of chagas disease.

Kissing bugs have long served as models to study many aspects of insect physiology. They also serve as vectors for the parasite Trypanosoma cruzi that causes Chagas disease in humans. The overall success of insects is due, in part, to their ability to recognize parasites and pathogens as non-self and to eliminate them using their innate immune system.

Rhodnius prolixus: Identification of missing components of the IMD immune signaling pathway and functional characterization of its role in eliminating bacteria.

The innate immune system in insects is regulated by specific signalling pathways. Most immune related pathways were identified and characterized in holometabolous insects such as Drosophila melanogaster, and it was assumed they would be highly conserved in all insects. The hemimetabolous insect, Rhodnius prolixus, has served as a model to study basic insect physiology, but also is a major vector of the human parasite, Trypanosoma cruzi, that causes 10,000 deaths annually.

The Composition of Midgut Bacteria in Aedes aegypti (Diptera: Culicidae) That Are Naturally Susceptible or Refractory to Dengue Viruses.

The composition, abundance, and diversity of midgut bacteria in mosquitoes can influence pathogen transmission. We used 16S rRNA microbiome profiling to survey midgut microbial diversity in pooled samples of laboratory colonized dengue-refractory, Cali-MIB, and dengue-susceptible, Cali-S Aedes aegypti (Linnaeus). The 16S rRNA sequences from the sugar-fed midguts of adult females clustered to 63 amplicon sequence variants (ASVs), primarily from Proteobacteria, Firmicutes, Flavobacteria, and Actinobacteria.