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Earlier studies with montelukast (M) and telmisartan (T) have revealed their potential antiviral properties against SARS-CoV-2 wild-type (WT) but have not assessed their efficacy against emerging Variants of Concern (VOCs) such as Omicron. Our research fills this gap by investigating these drugs’ impact on VOCs, a topic that current scientific literature has largely overlooked. We employed computational methodologies, including molecular mechanics and machine learning tools, to identify drugs that could potentially disrupt the SARS-CoV-2 spike RBD-ACE2 protein interaction. This led to the identification of two FDA-approved small molecule drugs, M and T, conventionally used for treating asthma and hypertension, respectively. Our study presents an additional potential use for these drugs as antivirals. Our results show that both M and T can inhibit not only the WT SARS-CoV-2 but also, in the case of M, the Omicron variant, without reaching cytotoxic concentrations. This novel finding fills an existing gap in the literature and introduces the possibility of repurposing these drugs for SARS-CoV-2 VOCs, an essential step in responding to the evolving global pandemic.

Flies and other arthropods mechanically transmit multiple pathogens and a recent experimental study demonstrated house flies, Musca domestica L. (Diptera: Muscidae), can mechanically transmit SARS-CoV-2. The purpose of this study was to explore the possibility of mechanical transmission of SARS-CoV-2 by domestic insects and their potential as a xenosurveillance tool for detection of the virus. Flies were trapped in homes where at least one confirmed human COVID-19 case(s) resided using sticky and liquid-baited fly traps placed inside and outside the home in the Texas counties of Brazos, Bell, and Montgomery, from June to September 2020. Flies from sticky traps were identified, pooled by taxa, homogenized, and tested for the presence of SARS-CoV-2 RNA using quantitative reverse transcription PCR (RT-qPCR). Liquid traps were drained, and the collected fluid similarly tested after RNA concentration. We processed the contents of 133 insect traps from 40 homes, which contained over 1,345 individual insects of 11 different Diptera families and Blattodea. These individuals were grouped into 243 pools, and all tested negative for SARS-CoV-2 RNA. Fourteen traps in seven homes were deployed on the day that cat or dog samples tested positive for SARS-CoV-2 RNA by nasal, oral, body, or rectal samples. This study presents evidence that biting and nonbiting flies and cockroaches (Blattodea) are not likely to contribute to mechanical transmission of SARS-CoV-2 or be useful in xenosurveillance for SARS-CoV-2.

Using the regioselective cyanobenzothiazole condensation reaction with an N-terminal cysteine and the chloroacetamide reaction with an internal cysteine, a phage-displayed macrocyclic 12-mer peptide library was constructed and subsequently validated. Using this library in combination with iterative selections against two epitopes from the receptor binding domain (RBD) of the novel severe acute respiratory syndrome virus 2 (SARS-CoV-2) Spike protein, macrocyclic peptides that strongly inhibit the interaction between the Spike RBD and angiotensin-converting enzyme 2 (ACE2), the human host receptor of SARS-CoV-2, were identified. The two epitopes were used instead of the Spike RBD to avoid selection of nonproductive macrocyclic peptides that bind RBD but do not directly inhibit its interactions with ACE2. Antiviral tests against SARS-CoV-2 showed that one macrocyclic peptide is highly potent against viral reproduction in Vero E6 cells with an EC

Using the regioselective cyanobenzothiazole condensation reaction with the N-terminal cysteine and the chloroacetamide reaction with an internal cysteine, a phage-displayed macrocyclic 12-mer peptide library was constructed and subsequently validated. Using this library in combination with iterative selections against two epitopes from the receptor binding domain (RBD) of the SARS-CoV-2 Spike protein, macrocyclic peptides that strongly inhibit the interaction between the Spike RBD and ACE2, the human host receptor of SARS-CoV-2, were identified. The two epitopes were used instead of the Spike RBD to avoid selection of nonproductive macrocyclic peptides that bind RBD but do not directly inhibit its interactions with ACE2. Antiviral tests against SARS-CoV-2 showed that one macrocyclic peptide is highly potent against viral reproduction in Vero E6 cells with an EC50 value of 3.1 μM. The AlphaLISA-detected IC50 value for this macrocyclic peptide was 0.3 μM. The current study demonstrates that two kinetically-controlled reactions toward N-terminal and internal cysteines, respectively, are highly effective in the construction of phage-displayed macrocyclic peptides, and the selection based on the SARS-CoV-2 Spike epitopes is a promising methodology in the identification of peptidyl antivirals.

Background:The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a pandemic of coronavirus disease (COVID-19), which continues to cause infections and mortality worldwide. SARS-CoV-2 is transmitted primarily via the respiratory route and has experimentally been found to be stable on surfaces for multiple days. Flies (Diptera) and other arthropods mechanically transmit several pathogens, including turkey coronavirus. A previous experimental study demonstrated house flies, Musca domestica, can mechanically transmit SARS-CoV-2, but the ability of flies in general to acquire and deposit this virus in natural settings has not been explored. The purpose of this study was to explore the possibility of mechanical transmission of SARS-CoV-2 by peridomestic insects and their potential as a xenosurveillance tool for detection of the virus.Methods:In order to optimize chances of viral detection, flies were trapped in homes where at least one confirmed human COVID-19 case(s) resided. Sticky and liquid baited fly traps were deployed inside and outside of the homes of SARS-CoV-2 human cases in Brazos, Bell, and Montgomery Counties, from June to September 2020. Flies from sticky traps were identified, pooled by taxa, homogenized, and tested for the presence of SARS-CoV-2 RNA using qRT-PCR. Liquid traps were drained, and the collected fluid similarly tested after RNA concentration. Experimental viral detection pipeline and viral inactivation were confirmed in a Biosafety Level 3 lab. As part of a separate ongoing study, companion animals in the home were sampled and tested for SARS-CoV-2 on the same day of insect trap deployment.Results:We processed the contents of 133 insect traps from 44 homes, which contained over 1,345 individual insects of 11 different Diptera families and Blattodea.These individuals were grouped into 243 pools, and all tested negative for SARS-CoV-2 RNA. Dead flies exposed to SARS-CoV-2 in a BSL3 lab were processed using the same methods and viral RNA was detected by RT-PCR. Fourteen traps in seven homes were deployed on the day that cat or dog samples tested positive for SARS-CoV-2 RNA by nasal, oral, body, or rectal samples.Conclusions:This study presents evidence that biting and non-biting flies are not likely to contribute to mechanical transmission of SARS-CoV-2 or be useful in xenosurveillance for SARS-CoV-2.

Understanding the ecological and epidemiological roles of pets in the transmission of SARS-CoV-2 is critical for animal and human health, identifying household reservoirs, and predicting the potential enzootic maintenance of the virus. We conducted a longitudinal household transmission study of 76 dogs and cats living with at least one SARS-CoV-2-infected human in Texas and found that 17 pets from 25.6% of 39 households met the national case definition for SARS-CoV-2 infections in animals. This includes three out of seventeen (17.6%) cats and one out of fifty-nine (1.7%) dogs that were positive by RT-PCR and sequencing, with the virus successfully isolated from the respiratory swabs of one cat and one dog. Whole-genome sequences of SARS-CoV-2 obtained from all four PCR-positive animals were unique variants grouping with genomes circulating among people with COVID-19 in Texas. Re-sampling showed persistence of viral RNA for at least 25 d-post initial test. Additionally, seven out of sixteen (43.8%) cats and seven out of fifty-nine (11.9%) dogs harbored SARS-CoV-2 neutralizing antibodies upon initial sampling, with relatively stable or increasing titers over the 2–3 months of follow-up and no evidence of seroreversion. The majority (82.4%) of infected pets were asymptomatic. ‘Reverse zoonotic’ transmission of SARS-CoV-2 from infected people to animals may occur more frequently than recognized.

An integral part to integrated mosquito management is to ensure chemical products used for area-wide control are effective against a susceptible population of mosquitoes. Prior to conducting an intervention trial using an insect growth regulator, pyriproxyfen, in South Texas to control Aedes aegypti, we conducted a larval bioassay to evaluate baseline levels of susceptibility. We used seven serially-diluted doses ranging from 2.5 ppb to 6.3 × 10−4 ppb. We observed 100% inhibition emergence (IE) at even the lowest dose of 6.3 × 10−4 ppb in our susceptible reference colony of Ae. aegypti Liverpool. In our field strain of Ae. aegypti (F5 colonized from South Texas) we observed 79.8% IE at 6.3 × 10−4 ppb, 17.7% IE at 1.25 × 10−3 ppb, 98.7% IE at 1.25 × 10−2 ppb, and 100% emergence inhibition for the remainder of the doses. Given that commercial pyriproxyfen products are labeled for doses ranging to 50 ppb, we conclude that the field population sampled by this study are susceptible to this insect growth regulator.

As part of a longitudinal household transmission study of pets living with persons with COVID-19 in Texas, two pets were confirmed to be infected with the SARS-CoV-2 B.1.1.7 variant of concern (VOC). The pets were a dog and a cat from the same household, sampled two days after their owner tested positive for COVID-19. The oral, nasal, and fur swabs for both pets tested positive for SARS-CoV-2 by qRT-PCR and consensus whole genome sequences from the dog and cat were 100 % identical and matched the B.1.1.7 VOC. Virus was isolated from the cat’s nasal swab. One month after initial detection of infection, the pets were re-tested twice at which time only the fur swabs (both pets) and oral swab (dog only) remained positive, and neutralizing antibodies for SARS-CoV-2 were present in both animals. Sneezing by both pets was noted by the owner in the weeks between initial and follow-up testing. This study documents the first detection of B.1.1.7. in companion animals in the United States, and the first genome recovery and isolation of B.1.1.7 variant of concern globally in any animal.

How microbe–microbe interactions dictate microbial complexity in the mosquito gut is unclear. Previously we found that, Serratia, a gut symbiont that alters vector competence and is being considered for vector control, poorly colonized Aedes aegypti yet was abundant in Culex quinquefasciatus reared under identical conditions. To investigate the incompatibility between Serratia and Ae. aegypti, we characterized two distinct strains of Serratia marcescens from Cx. quinquefasciatus and examined their ability to infect Ae. aegypti. Both Serratia strains poorly infected Ae. aegypti, but when microbiome homeostasis was disrupted, the prevalence and titers of Serratia were similar to the infection in its native host. Examination of multiple genetically diverse Ae. aegypti lines found microbial interference to S. marcescens was commonplace, however, one line of Ae. aegypti was susceptible to infection. Microbiome analysis of resistant and susceptible lines indicated an inverse correlation between Enterobacteriaceae bacteria and Serratia, and experimental co-infections in a gnotobiotic system recapitulated the interference phenotype. Furthermore, we observed an effect on host behavior; Serratia exposure to Ae. aegypti disrupted their feeding behavior, and this phenotype was also reliant on interactions with their native microbiota. Our work highlights the complexity of host–microbe interactions and provides evidence that microbial interactions influence mosquito behavior.

The natural infections and epidemiological roles of household pets in SARS-CoV-2 transmission are not understood. We conducted a longitudinal study of dogs and cats living with at least one SARS-CoV-2 infected human in Texas and found 47.1% of 17 cats and 15.3% of 59 dogs from 25.6% of 39 households were positive for SARS-CoV-2 via RT-PCR and genome sequencing or neutralizing antibodies. Virus was isolated from one cat. The majority (82.4%) of infected pets were asymptomatic. Re-sampling of one infected cat showed persistence of viral RNA at least 32 d-post human diagnosis (25 d-post initial test). Across 15 antibody-positive animals, titers increased (33.3%), decreased (33.3%) or were stable (33.3%) over time. A One Health approach is informative for prevention and control of SARS-CoV-2 transmission.

How microbe-microbe interactions dictate microbial complexity in the mosquito gut is unclear. Previously we found that Serratia, a gut symbiont that alters vector competence and is being considered for vector control, poorly colonized Aedes aegypti yet was abundant in Culex quinquefasciatus reared under identical conditions. To investigate the incompatibility between Serratia and Ae. aegypti, we characterized two distinct strains of Serratia marcescens from Cx. quinquefasciatus and examined their ability to infect Ae. aegypti. Both Serratia strains poorly infected Ae. aegypti, but when microbiome homeostasis was disrupted, the prevalence and titers of Serratia were similar to the infection in its native host. Examination of multiple genetically diverse Ae. aegypti lines found microbial interference to S. marcescens was commonplace, however one line of Ae. aegypti was susceptible to infection. Microbiome analysis of resistant and susceptible lines indicated an inverse correlation between Enterobacteriaceae bacteria and Serratia, and experimental co-infections in a gnotobiotic system recapitulated the interference phenotype. Furthermore, we observed an effect on host behaviour; Serratia exposure to Ae. aegypti disrupted their feeding behaviour, and this phenotype was also reliant on interactions with their native microbiota. Our work highlights the complexity of host-microbe interactions and provides evidence that microbial interactions influence mosquito behaviour.

The establishment of a sylvatic reservoir of Zika virus (ZIKV) in the Americas is dependent on the susceptibility of primates of sufficient population density, the duration and magnitude of viremia, and their exposure to the human mosquito-borne transmission cycle. To assess the susceptibility of squirrel (Saimiri sp.) and owl monkeys (Aotus sp.) to infection, we inoculated four animals of each species with ZIKV from the current epidemic. Viremia in the absence of detectible disease was observed in both species and seroconversion occurred by day 28. ZIKV was detected in the spleen of three owl monkeys: one at 7 days postinoculation (dpi) and two at 14 dpi. This study confirms the susceptibility to ZIKV infection of two Neotropical primate species that live in close proximity to humans in South America, suggesting that they could support a widespread sylvatic ZIKV cycle there. Collectively, establishment of a ZIKV sylvatic transmission cycle in South America would imperil eradication efforts and could provide a mechanism for continued exposure of humans to ZIKV infection and disease.

University of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA. University of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA. University of Texas Medical Branch. Department of Microbiology & Immunology. Galveston, TX, USA. University of Texas Medical Branch. Institute for Human Infections & Immunity. Galveston, TX, USA / University of Texas Medical Branch. Institute for Translational Science. Galveston, TX, USA. University of Texas Medical Branch. Department of Microbiology & Immunology. Galveston, TX, USA / Minist?rio da Sa?de. Secretaria de Vigil?ncia em Sa?de. Instituto Evandro Chagas. Ananindeua, PA, Brasil. University of Texas Medical Branch. Department of Microbiology & Immunology. Galveston, TX, USA . University of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA. University of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA. University of Texas Medical Branch. Institute for Human Infections & Immunity. Galveston, TX, USA / University of Texas Medical Branch. Institute for Translational Science. Galveston, TX, USA. University of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA. University of Texas Medical Branch. Institute for Human Infections & Immunity. Galveston, TX, USA / University of Texas Medical Branch. Department of Pathology and Center for Biodefense & Emerging Infectious Diseases. Galveston, TX, USA. University of Texas Medical Branch. Department of Microbiology & Immunology. Galveston, TX, USA / University of Texas Medical Branch. Department of Pathology and Center for Biodefense & Emerging Infectious Diseases. Galveston, TX, USA / University of Texas Medical Branch. Sealy Center for Vaccine Development. Galveston, TX, USA. University of Texas Medical Branch. Institute for Human Infections & Immunity. Galveston, TX, USA / University of Texas Medical Branch. Institute for Translational Science. Galveston, TX, USA / University of Texas Medical Branch. Department of Microbiology & Immunology. Galveston, TX, USA / University of Texas Medical Branch. Sealy Center for Vaccine Development. Galveston, TX, USA / University of Texas Medical Branch. Sealy Center for Structural Biology & Molecular Biophysics. Galveston, TX, USA. University of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA / University of Texas Medical Branch. Sealy Center for Vaccine Development. Galveston, TX, USA / University of Texas Medical Branch. Department of Pharmacology & Toxicology. Galveston, TX, USA / University of Texas Medical Branch. Sealy Center for Structural Biology & Molecular Biophysics. Galveston, TX, USA. Zika virus (ZIKV) infection causes devastating congenital abnormities and Guillain-Barre? syndrome. The ZIKV envelope (E) protein is responsible for viral entry and represents a major determinant for viral pathogenesis. Like other flaviviruses, the ZIKV E protein is glycosylated at amino acid N154. To study the function of E glycosylation, we generated a recombinant N154Q ZIKV that lacks the E glycosylation and analyzed the mutant virus in mammalian and mosquito hosts. In mouse models, the mutant was attenuated, as evidenced by lower viremia, decreased weight loss, and no mortality; however, knockout of E glycosylation did not significantly affect neurovirulence. Mice immunized with the mutant virus developed a robust neutralizing antibody response and were completely protected from wild-type ZIKV challenge. In mosquitoes, the mutant virus exhibited diminished oral infectivity for the Aedes aegypti vector. Collectively, the results demonstrate that E glycosylation is critical for ZIKV infection of mammalian and mosquito hosts.

To evaluate the potential role of Aedes albopictus (Skuse) as a vector of Zika virus (ZIKV), colonized mosquitoes of low generation number (≤ F5) from Brazil, Houston, and the Rio Grande Valley of Texas engorged on viremic mice infected with ZIKV strains originating from Senegal, Cambodia, Mexico, Brazil, or Puerto Rico. Vector competence was established by monitoring infection, dissemination, and transmission potential after 3, 7, and 14 days of extrinsic incubation. Positive saliva samples were assayed for infectious titer. Although all three mosquito populations were susceptible to all ZIKV strains, rates of infection, dissemination, and transmission differed among mosquito and virus strains. Aedes albopictus from Salvador, Brazil, were the least efficient vectors, demonstrating susceptibility to infection to two American strains of ZIKV but failing to shed virus in saliva. Mosquitoes from the Rio Grande Valley were the most efficient vectors and were capable of shedding all three tested ZIKV strains into saliva after 14 days of extrinsic incubation. In particular, ZIKV strain DakAR 41525 (Senegal 1954) was significantly more efficient at dissemination and saliva deposition than the others tested in Rio Grande mosquitoes. Overall, our data indicate that, while Ae. albopictus is capable of transmitting ZIKV, its competence is potentially dependent on geographic origin of both the mosquito population and the viral strain.

Background Aedes aegypti, the principal vector for dengue, chikungunya and Zika viruses, is a synanthropic species that uses stagnant water to complete its reproductive cycle. In urban settings, rainfall water draining structures, such as storm drains, may retain water and serve as a larval development site for Aedes spp. reproduction. Herein, we describe the effect of a community-based intervention on preventing standing water accumulation in storm drains and their consequent infestation by adult and immature Ae. aegypti and other mosquitoes. Methods Between April and May of 2016, local residents association of Salvador, Brazil, after being informed of water accumulation and Ae. aegypti infestation in the storm drains in their area, performed an intervention on 52 storm drains. The intervention consisted of placing concrete at the bottom of the storm drains to elevate their base to the level of the outflow tube, avoiding water accumulation, and placement of a metal mesh covering the outflow tube to avoid its clogging with debris. To determine the impact of the intervention, we compared the frequency at which the 52 storm drains contained water, as well as adult and immature mosquitoes using data from two surveys performed before and two surveys performed after the intervention. Results During the pre-intervention period, water accumulated in 48 (92.3%) of the storm drains, and immature Ae. aegypti were found in 11 (21.2%) and adults in 10 (19.2%). After the intervention, water accumulated in 5 (9.6%) of the storm drains (P

To test whether Zika virus has adapted for more efficient transmission by Aedes aegypti mosquitoes, leading to recent urban outbreaks, we fed mosquitoes from Brazil, the Dominican Republic, and the United States artificial blood meals containing 1 of 3 Zika virus strains (Senegal, Cambodia, Mexico) and monitored infection, dissemination, and virus in saliva. Contrary to our hypothesis, Cambodia and Mexica strains were less infectious than the Senegal strain. Only mosquitoes from the Dominican Republic transmitted the Cambodia and Mexica strains. However, blood meals from viremic mice were more infectious than artificial blood meals of comparable doses; the Cambodia strain was not transmitted by mosquitoes from Brazil after artificial blood meals, whereas 61% transmission occurred after a murine blood meal (saliva titers up to 4 log 10 infectious units/collection). Although regional origins of vector populations and virus strain influence transmission efficiency, Ae. aegypti mosquitoes appear to be competent vectors of Zika virus in several regions of the Americas.

Summary Zika virus (ZIKV) infection causes microcephaly in a subset of infants born to infected pregnant mothers. It is unknown whether human individual differences contribute to differential susceptibility of ZIKV-related neuropathology. Here, we use an Asian-lineage ZIKV strain, isolated from the 2015 Mexican outbreak (Mex1-7), to infect primary human neural stem cells (hNSCs) originally derived from three individual fetal brains. All three strains of hNSCs exhibited similar rates of Mex1-7 infection and reduced proliferation. However, Mex1-7 decreased neuronal differentiation in only two of the three stem cell strains. Correspondingly, ZIKA-mediated transcriptome alterations were similar in these two strains but significantly different from that of the third strain with no ZIKV-induced neuronal reduction. This study thus confirms that an Asian-lineage ZIKV strain infects primary hNSCs and demonstrates a cell-strain-dependent response of hNSCs to ZIKV infection., Graphical Abstract, Highlights • Mexican ZIKV strain infects primary human fetal brain-derived neural stem cells • ZIKV inhibits neuronal differentiation in a cell-strain-dependent manner • Majority of differentiated ZIKV-infected cells are glial cells • ZIKV-mediated transcriptome alteration is cell-strain-dependent, In this article, Wu, Vasilakis, and colleagues demonstrate the infection of primary human fetal brain-derived neural stem cells by a 2015 Mexican strain of ZIKV. They show that ZIKV is cytotoxic and inhibits proliferation independent of different human origins, but inhibits neuronal differentiation and alters gene expression in a cell-strain-dependent manner.

Background. After decades of obscurity, Zika virus (ZIKV) has spread through the Americas since 2015 accompanied by congenital microcephaly and Guillain-Barre syndrome. Although these epidemics presumably involve transmission by Aedes aegypti, no direct evidence of vector involvement has been reported, prompting speculation that other mosquitoes such as Culex quinquefasciatus could be involved. Methods. We detected an outbreak of ZIKV infection in southern Mexico in late 2015. Sera from suspected ZIKV-infected patients were analyzed for viral RNA and antibodies. Mosquitoes were collected in and around patient homes and tested for ZIKV. Results. Of 119 suspected ZIKV-infected patients, 25 (21%) were confirmed by RT-PCR of serum collected 1–8 days after the onset of signs and symptoms including rash, arthralgia, headache, pruritus, myalgia, and fever. Of 796 mosquitoes collected, A. aegypti yielded ZIKV detection by RT-PCR in 15 of 55 pools (27.3%). No ZIKV was detected in C. quinquefasciatus. ZIKV sequences derived from sera and mosquitoes showed a monophyletic relationship suggestive of a point source introduction from Guatemala. Conclusions. These results demonstrate the continued, rapid northward progression of ZIKV into North America with typically mild disease manifestations, and implicate A. aegypti for the first time as a principal vector in North America.

The Asian lineage of Zika virus (ZIKV) has recently caused epidemics and severe disease. Unraveling the mechanisms causing increased viral transmissibility and disease severity requires experimental systems. We report an infectious cDNA clone of ZIKV that was generated using a clinical isolate of the Asian lineage. The cDNA clone-derived RNA is infectious in cells, generating recombinant ZIKV. The recombinant virus is virulent in established ZIKV mouse models, leading to neurological signs relevant to human disease. Additionally, recombinant ZIKV is infectious for Aedes aegypti and thus provides a means to examine virus transmission. The infectious cDNA clone was further used to generate a luciferase ZIKV that exhibited sensitivity to a pan-flavivirus inhibitor, highlighting its potential utility for antiviral screening. This ZIKV reverse genetic system, together with mouse and mosquito infection models, may help identify viral determinants of human virulence and mosquito transmission, as well as inform vaccine and therapeutic strategies.

To evaluate the effects of ZIKV infection on non-human primates (NHPs), as well as to investigate whether these NHPs develop sufficient viremia to infect the major urban vector mosquito, Aedes aegypti, four cynomolgus macaques (Macaca fascicularis) were subcutaneously infected with 5.0 log10 focus-forming units (FFU) of DNA clone-derived ZIKV strain FSS13025 (Asian lineage, Cambodia, 2010). Following infection, the animals were sampled (blood, urine, tears, and saliva), underwent daily health monitoring, and were exposed to Ae. aegypti at specified time points. All four animals developed viremia, which peaked 3&ndash, 4 days post-infection at a maximum value of 6.9 log10 genome copies/mL. No virus was detected in urine, tears, or saliva. Infection by ZIKV caused minimal overt disease: serum biochemistry and CBC values largely fell within the normal ranges, and cytokine elevations were minimal. Strikingly, the minimally colonized population of Ae. aegypti exposed to viremic animals demonstrated a maximum infection rate of 26% during peak viremia, with two of the four macaques failing to infect a single mosquito at any time point. These data indicate that cynomolgus macaques may be an effective model for ZIKV infection of humans and highlights the relative refractoriness of Ae. aegypti for ZIKV infection at the levels of viremia observed.

To evaluate the potential role of Aedes albopictus (Skuse) as a vector of Zika virus (ZIKV), colonized mosquitoes of low generation number (≤ F5) from Brazil, Houston, and the Rio Grande Valley of Texas engorged on viremic mice infected with ZIKV strains originating from Senegal, Cambodia, Mexico, Brazil, or Puerto Rico. Vector competence was established by monitoring infection, dissemination, and transmission potential after 3, 7, and 14 days of extrinsic incubation. Positive saliva samples were assayed for infectious titer. Although all three mosquito populations were susceptible to all ZIKV strains, rates of infection, dissemination, and transmission differed among mosquito and virus strains. Aedes albopictus from Salvador, Brazil, were the least efficient vectors, demonstrating susceptibility to infection to two American strains of ZIKV but failing to shed virus in saliva. Mosquitoes from the Rio Grande Valley were the most efficient vectors and were capable of shedding all three tested ZIKV strains into saliva after 14 days of extrinsic incubation. In particular, ZIKV strain DakAR 41525 (Senegal 1954) was significantly more efficient at dissemination and saliva deposition than the others tested in Rio Grande mosquitoes. Overall, our data indicate that, while Ae. albopictus is capable of transmitting ZIKV, its competence is potentially dependent on geographic origin of both the mosquito population and the viral strain.

Arthropod-borne viruses (arboviruses) have in recent years become a tremendous global health concern resulting in substantial human morbidity and mortality. With the widespread utilization of molecular technologies such as next-generation sequencing and the advancement of bioinformatics tools, a new age of viral discovery has commenced. Many of the novel agents being discovered in recent years have been isolated from mosquitoes and exhibit a highly restricted host range. Strikingly, these insect-specific viruses have been found to be members of viral families traditionally associated with human arboviral pathogens, including but not limited to the families Flaviviridae, Togaviridae, Reoviridae, and Bunyaviridae. These agents therefore present novel opportunities in the fields of viral evolution and viral/vector interaction and have tremendous potential as agents for biocontrol of vectors and or viruses of medical importance.

Arthropod-borne viruses (arboviruses) have in recent years become a tremendous global health concern resulting in substantial human morbidity and mortality. With the widespread utilization of molecular technologies such as next-generation sequencing and the advancement of bioinformatics tools, a new age of viral discovery has commenced. Many of the novel agents being discovered in recent years have been isolated from mosquitoes and exhibit a highly restricted host range. Strikingly, these insect-specific viruses have been found to be members of viral families traditionally associated with human arboviral pathogens, including but not limited to the families Flaviviridae, Togaviridae, Reoviridae, and Bunyaviridae. These agents therefore present novel opportunities in the fields of viral evolution and viral/vector interaction and have tremendous potential as agents for biocontrol of vectors and or viruses of medical importance.

Alphaviruses require conserved cysteine residues for proper folding and assembly of the E1 and E2 envelope glycoproteins, and likely depend on host protein disulfide isomerase-family enzymes (PDI) to aid in facilitating disulfide bond formation and isomerization in these proteins. Here, we show that in human HEK293 cells, commercially available inhibitors of PDI or modulators thereof (thioredoxin reductase, TRX-R; endoplasmic reticulum oxidoreductin-1, ERO-1) inhibit the replication of CHIKV chikungunya virus (CHIKV) in vitro in a dose-dependent manner. Further, the TRX-R inhibitor auranofin inhibited Venezuelan equine encephalitis virus and the flavivirus Zika virus replication in vitro, while PDI inhibitor 16F16 reduced replication but demonstrated notable toxicity. 16F16 significantly altered the viral genome: plaque-forming unit (PFU) ratio of CHIKV in vitro without affecting relative intracellular viral RNA quantities and inhibited CHIKV E1-induced cell-cell fusion, suggesting that PDI inhibitors alter progeny virion infectivity through altered envelope function. Auranofin also increased the extracellular genome:PFU ratio but decreased the amount of intracellular CHIKV RNA, suggesting an alternative mechanism of action. Finally, auranofin reduced footpad swelling and viremia in the C57BL/6 murine model of CHIKV infection. Our results suggest that targeting oxidative folding pathways represents a potential new anti-alphavirus therapeutic strategy.

Zika virus has recently spread throughout the Americas. Although Aedes aegypti mosquitoes are considered the primary vector, Culex quinquefasciatus and mosquitoes of other species may also be vectors. We tested Cx. quinquefasciatus and Ae. taeniorhynchus mosquitoes from the US Gulf Coast; both were refractory to infection and incapable of transmission.

Dengue virus (DENV) is a mosquito-borne flavivirus that causes serious human disease and mortality worldwide. There is no specific antiviral therapy or vaccine for DENV infection. Alterations in gene expression during DENV infection of the mosquito and the impact of these changes on virus infection are important events to investigate in hopes of creating new treatments and vaccines. We previously identified 203 genes that were ≥5-fold differentially upregulated during flavivirus infection of the mosquito. Here, we examined the impact of silencing 100 of the most highly upregulated gene targets on DENV infection in its mosquito vector. We identified 20 genes that reduced DENV infection by at least 60% when silenced. We focused on one gene, a putative cysteine rich venom protein (SeqID AAEL000379; CRVP379), whose silencing significantly reduced DENV infection in Aedes aegypti cells. Here, we examine the requirement for CRVP379 during DENV infection of the mosquito and investigate the mechanisms surrounding this phenomenon. We also show that blocking CRVP379 protein with either RNAi or specific antisera inhibits DENV infection in Aedes aegypti. This work identifies a novel mosquito gene target for controlling DENV infection in mosquitoes that may also be used to develop broad preventative and therapeutic measures for multiple flaviviruses., Author Summary Dengue virus (DENV) is responsible for serious human disease worldwide and the World Health Organization estimates that over 2 billion people are at risk for disease. There are no vaccines or specific antiviral medications currently available for DENV infection. DENV is transmitted to humans by infected mosquitoes during feeding and probing. By examining the effects of virus infection on gene expression, and interactions between virus and vector, we may be able to find new targets for prevention and treatment. Here we look at a mosquito protein, CRVP379, whose gene expression was highly increased during DENV infection in mosquitoes. We show a requirement for CRVP379 during DENV infection in the mosquito and a correlation between the levels of CRVP379 and levels of infection. Our results indicate that the protein may be acting with a putative DENV receptor in the mosquito, prohibitin protein. These data also suggest that blocking CRVP379 function may be used to block DENV infection in the mosquito.

Response to: ‘Lack of evidence for Zika virus transmission by Culex mosquitoes’https://www.nature.com/articles/emi201786doi:10.1038/emi.2017.86; International audience; LETTER TO THE EDITORDear Editor,Since Zika virus (ZIKV) emerged in the Americas, major research efforts have been focused on identifying the mosquito species responsible for transmission. [...]