Rhodnius prolixus not only has served as a model organism for the study of insect physiology, but also is a major vector of Chagas disease, an illness that affects approximately seven million people worldwide. We sequenced the genome of R. prolixus, generated assembled sequences covering 95% of the genome (∼702 Mb), including 15,456 putative protein-coding genes, and completed comprehensive genomic analyses of this obligate blood-feeding insect. Although immune-deficiency (IMD)-mediated immune responses were observed, R. prolixus putatively lacks key components of the IMD pathway, suggesting a reorganization of the canonical immune signaling network. Although both Toll and IMD effectors controlled intestinal microbiota, neither affected Trypanosoma cruzi, the causal agent of Chagas disease, implying the existence of evasion or tolerance mechanisms. R. prolixus has experienced an extensive loss of selenoprotein genes, with its repertoire reduced to only two proteins, one of which is a selenocysteine-based glutathione peroxidase, the first found in insects. The genome contained actively transcribed, horizontally transferred genes from Wolbachia sp., which showed evidence of codon use evolution toward the insect use pattern. Comparative protein analyses revealed many lineage-specific expansions and putative gene absences in R. prolixus, including tandem expansions of genes related to chemoreception, feeding, and digestion that possibly contributed to the evolution of a blood-feeding lifestyle. The genome assembly and these associated analyses provide critical information on the physiology and evolution of this important vector species and should be instrumental for the development of innovative disease control methods.

Background: Wolbachia, a common insect endosymbiotic bacterium that can influence pathogen transmission and manipulate host reproduction, has historically been considered absent from the Anopheles (An.) genera, but has recently been found in An. gambiae s.l. populations in West Africa.  As there are numerous Anopheles species that have the capacity to transmit malaria, we analysed a range of species across five malaria endemic countries to determine Wolbachia prevalence rates, characterise novel Wolbachia strains and determine any correlation between the presence of Plasmodium, Wolbachia and the competing bacterium Asaia. Methods: Anopheles adult mosquitoes were collected from five malaria-endemic countries: Guinea, Democratic Republic of the Congo (DRC), Ghana, Uganda and Madagascar, between 2013 and 2017.  Molecular analysis was undertaken using quantitative PCR, Sanger sequencing, Wolbachia multilocus sequence typing (MLST) and high-throughput amplicon sequencing of the bacterial 16S rRNA gene.  Results: Novel Wolbachia strains were discovered in five species: An. coluzzii, An. gambiae s.s., An. arabiensis, An. moucheti and An. species A, increasing the number of Anopheles species known to be naturally infected. Variable prevalence rates in different locations were observed and novel strains were phylogenetically diverse, clustering with Wolbachia supergroup B strains.  We also provide evidence for resident strain variants within An. species A. Wolbachia is the dominant member of the microbiome in An. moucheti and An. species A but present at lower densities in An. coluzzii.  Interestingly, no evidence of Wolbachia/Asaia co-infections was seen and Asaia infection densities were shown to be variable and location dependent.  Conclusions: The important discovery of novel Wolbachia strains in Anopheles provides greater insight into the prevalence of resident Wolbachia strains in diverse malaria vectors.  Novel Wolbachia strains (particularly high-density strains) are ideal candidate strains for transinfection to create stable infections in other Anopheles mosquito species, which could be used for population replacement or suppression control strategies.

Insecticide resistance across sub-Saharan Africa may impact the continued effectiveness of malaria vector control. We investigated the association between carbamate and pyrethroid resistance with Anopheles gambiae s.l. parity, Plasmodium falciparum infection, and molecular insecticide resistance mechanisms in Guinea. Pyrethroid resistance was intense, with field populations surviving ten times the insecticidal concentration required to kill susceptible individuals. The L1014F kdr -N1575Y haplotype and I1527T mutation were significantly associated with mosquito survival following permethrin exposure (Prevalence Ratio; PR = 1.92, CI = 1.09–3.37 and PR = 2.80, CI = 1.03–7.64, respectively). Partial restoration of pyrethroid susceptibility following synergist pre-exposure suggests a role for mixed-function oxidases. Carbamate resistance was lower and significantly associated with the G119S Ace-1 mutation. Oocyst rates were 6.8% and 4.2% among resistant and susceptible mosquitoes, respectively; survivors of bendiocarb exposure were significantly more likely to be infected. Pyrethroid resistant mosquitoes had significantly lower parity rates than their susceptible counterparts (PR = 1.15, CI = 1.10–1.21). Our findings emphasize the need for additional studies directly assessing the influence of insecticide resistance on mosquito fitness.

A survey of triatomine insects found that 41.5% were infected with the causative agent of Chagas disease.

To our knowledge, this is the first report of T. cruzi transmission associated with heart transplantation. Clinicians and public health authorities should be aware that manifestations of Chagas disease can occur after transplantation, requiring rapid evaluation, diagnosis, and treatment.

Polymerase chain reaction analysis, direct DNA sequencing, and histological staining were used to determine whether Pneumocystis jirovecii was present in lung tissue specimens obtained, at autopsy, from 58 infants without identifiable immunodeficiency. The results of genotyping of these specimens were compared with the results of genotyping of specimens obtained from 384 human immunodeficiency virus (HIV)-infected adults with Pneumocystis pneumonia. P. jirovecii DNA was detected at the mitochondrial large subunit rRNA and dihydropteroate synthase loci in 100% and 53%, respectively, of the specimens obtained from infants. All specimens obtained from adults tested positive for P. jirovecii at both loci. Genotype distributions at both loci were significantly different in the 2 populations ( ). The obser-P ! .0001 vation of different strains circulating in immunocompetent infants and HIV-infected adults suggests independent transmission cycles that warrant further study.Pneumocystis pneumonia (PCP) is the most common life-threatening opportunistic infection among persons with AIDS in the

West Nile virus (WNV) has emerged as a health threat to the North American population since its initial outbreak in New York City in 1999. Culex (Culex) pipiens complex mosquitoes have been considered to play the primary role in the enzootic maintenance and transmission of WNV in North America. The voltage-gated sodium channel (NaCh) gene contains pyrethroid resistance-associated mutations in the coding region in many insect species. However, the knowledge of potential NaCh mutations was minimal in Culex. Seeking pyrethroid resistance alleles in Culex, we evaluated a transect along the east coast of the United States with an NaCh-based genotyping tool that amplified a portion of the transcribed sequence containing kdr mutations and the intron immediately downstream of the mutation site. Three genotypes that are typically associated with pyrethroid resistance in insects have been identified in Culex pipiens complex mosquitoes in this study: susceptible wild type kds, the classical knock-down resistance Leu --> Phe mutation (Phe/kdr), and a second resistance mechanism, a Leu --> Ser mutation (Ser/kdr). Moreover, we observed heterozygotic individual mosquitoes possessing both kdr alleles. Results of this study advance our knowledge of the potential for pyrethroid insecticide resistance among the populations of Cx. pipiens complex in the United States.

Triatomine bugs are a group of hematophagous arthropods that can serve as biological vectors for Trypanosoma cruzi , the etiological agent of American trypanosomiasis (Chagas disease). Because of differences in the biology and feeding habits among triatomine species, some are more likely than others to be involved in zoonotic and/or human-to-human transmission cycles of T. cruzi . In an attempt to assess the risk for Chagas disease exposure in south-central Texas, human habitations across Texas Health Service Region 8 (HSR 8) and surrounding counties were surveyed for triatomines to characterize the geographic distribution, species-specific biology, and T. cruzi -infection prevalence better. Between May 2010 and August 2013, a total of 545 triatomines representing all 5 known indigenous species (Triatoma gerstaeckeri, Triatoma indictiva, Triatoma lecticularia, Triatoma sanguisuga, and Triatoma protracta woodi) were collected from 59 sites across the region. Triatoma gerstaeckeri was the species most commonly found in domestic and peridomestic ecotopes across Texas HSR 8, representing over 80% of the triatomines collected. Adult T. gerstaeckeri exhibited a seasonal dispersal pattern that began in late April, peaked in mid-May, and then continued into August. On homes with available crevices in the exterior walls, adult T. gerstaeckeri were observed emerging from or entering these protective microhabitats, suggesting possible opportunistic colonization of some exterior walls compartments. Laboratory testing of triatomine hindgut contents for T. cruzi by PCR demonstrated the adult T. gerstaeckeri-infection prevalence across Texas HSR 8 to be 64%. Monitoring peridomestic adult T. gerstaeckeri over the seasonal dispersal peak demonstrated statistically significant increases in both their T. cruzi -infection prevalence (P < 0.01) and tendency to invade human dwellings (P < 0.01) in the later aspect of the emergence peak. In addition to the adult insects, variably sized and staged nymphs were recovered from the inside of 6 separate homes across Texas HSR 8. The results of this study show that T. gerstaeckeri is a widespread and common triatomine species across Texas HSR 8 and documented it to have some notable synanthropic tendencies. The high prevalence of T. cruzi infection in native triatomines, and the high frequency with which T. gerstaeckeri is recovered from human habitations, suggests that there is a risk for human exposure to T. cruzi in Texas HSR 8. Because of this, Chagas disease should be considered on the list of differential diagnoses for cases of cardiac arrhythmia, dilated cardiomyopathy, or heart failure in south-central Texas.