Ukauwa virus proliferation in mosquitoes

1968 ◽  
Vol 14 (2) ◽  
pp. 125-129 ◽  
Author(s):  
Oladeinde Ogunbi
Keyword(s):  
Aedes Aegypti ◽  
Salivary Glands ◽  
North American ◽  
Blood Meal ◽  
Mosquito Species ◽  
Infective Virus ◽  
Biological Criteria ◽  
Eclipse Phase ◽  
Initial Recovery ◽  
Intrathoracic Inoculation

Ukauwa virus, a Bunyamwera group arbovirus endemic in the Ethiopian zoogeographic region, multiplied in the tissues of North American mosquito species Aedes canadensis (Theobald) and Aedes triseriatus (Say) after intrathoracic inoculation. This virus also multiplied in laboratory-bred Aedes aegypti (L.) after both feeding and injection. Ukauwa virus now fulfills the biological criteria of an arbovirus. In these three mosquito species, after initial detection of infective virus immediately after inoculation, an eclipse phase with lack of detection of infectivity was observed 6 hours later, and was followed by initial recovery of virus (1.0 log mouse LD50) at 12 hours and thereafter steady virus increments in thorax, salivary glands, gut, and legs which reached maximum titers of 5.4 to 6.3 log mouse LD50 in 4 days. In A. aegypti fed Ukauwa virus no infectivity was detected during the first 8 days after the meal. After initial detection of infective virus (3.0 log mouse LD50) on day 10, maximum titers of 4.3 to 5.3 log mouse LD50 were reached 4 days later.A. aegypti transmitted Ukauwa virus to weaned mice on the 12th and 14th days after an infective blood meal, when virus titers in the salivary glands exceeded 4.3 log mouse LD50. The infection threshold of Ukauwa virus for A. aegypti by feeding was 4.7 log mouse LD50 per 0.002 ml.

scholarly journals Programmable CRISPR interference for gene silencing using Cas13a in mosquitoes

2019 ◽  
Author(s):  
Aditi Kulkarni ◽  
Wanqin Yu ◽  
Alex Moon ◽  
Ashmita Pandey ◽  
Kathryn A. Hanley ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Gene Silencing ◽  
Anopheles Gambiae ◽  
Blood Meal ◽  
Egg Production ◽  
Mosquito Species ◽  
Single Strand ◽  
Crispr Interference ◽  
Target Mrna

AbstractIn the CRISPR-Cas systems, Cas13a is an RNA-guided RNA nuclease specifically targeting single strand RNA. We developed a Cas13a mediated CRISPR interference tool to target mRNA for gene silencing in mosquitoes. The machinery was tested in two mosquito species. A Cas13a expressing plasmid was delivered to mosquitoes by intrathoracic injection, and Cas13a transcripts were detectable at least10 days post-delivery. In Anopheles gambiae, vitellogenin gene was silenced by Vg-crRNA injection two hours post-blood meal, which was accompanied by a significant reduction in egg production. In Aedes aegypti, the α- and δ-subunits of COPI genes were silenced by a post-blood meal crRNA injection, which resulted in mortality and fragile midguts, reproducing a phenotype reported previously. Co-silencing genes simultaneously is achievable when a cocktail of target crRNAs is given. No detectable collateral cleavages of non-target transcripts were observed in the study. This study adds a programmable CRISPR tool to manipulate RNA in mosquitoes.

Transmission of California encephalitis virus by mosquitoes

1968 ◽  
Vol 14 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Max A. Chernesky
Keyword(s):  
Aedes Aegypti ◽  
Salivary Glands ◽  
Blood Meal ◽  
Neutralizing Antibodies ◽  
Animal Species ◽  
Virus Titer ◽  
Virus Detection ◽  
Virus Growth ◽  
Average Maximum ◽  
Subcutaneous Inoculation

Transmission of California encephalitis (CE) virus strain R2929 by groups of Aedes vexans (Meigen) mosquitoes to rabbits was accomplished 7 and 9 days after the insects had imbibed an infective blood meal. Aedes aegypti (L.) mosquitoes transmitted virus to newly hatched chickens by biting them 48, 96, and 144 hours after intrathoracic injection.CE vires was found in gut, thorax, legs, and salivary glands of pools of Aedes triseriatus (Say), Aedes canadensis (Theobald), and A. vexans mosquitoes after intrathoracic injection of 101.3 mouse LD50 per 0.003 ml of virus. Salivary glands contained a maximum virus titer of 105.0 mouse LD50 per anatomical unit 5 days after injection. A. aegypti mosquitoes also supported virus growth after intrathoracic injection but yielded higher virus titers (106.3 mouse LD50) in the salivary glands.The infection threshold of A. vexans fed CE virus was 102.0LD50 per insect. Immediately after ingestion of 102.0 LD50 of virus only the gut washings contained virus. Detection of virus was not accomplished again until 4 days later. Average maximum titers of 104.5 LD50 per salivary glands were found after 8 days of extrinsic incubation. The infection threshold of A. aegypti fed CE virus exceeded 104.5 LD50 per insect.New Zealand white rabbits and Leghorn chickens circulated CE virus in their blood, which attained peak titers of 102.5 mouse LD50 per 0.03 ml 48 and 72 hours respectively after subcutaneous inoculation, but weaned mice did not develop viremia. All three animal species produced neutralizing antibodies to CE virus 21 days after inoculation.

scholarly journals A haemocyte tropism for an arbovirus

2009 ◽  
Vol 90 (2) ◽  
pp. 292-296 ◽  
Author(s):  
Grishma R. Parikh ◽  
Jonathan D. Oliver ◽  
Lyric C. Bartholomay
Keyword(s):  
Aedes Aegypti ◽  
Salivary Glands ◽  
Virus Replication ◽  
Blood Meal ◽  
Blood Cells ◽  
Sindbis Virus ◽  
Post Injection ◽  
Micro Organisms

Horizontally transmitted mosquito-borne viruses enter the midgut with a blood meal then disseminate to infect the salivary glands. En route to the salivary glands, these viruses encounter the plasma (haemolymph) and blood cells (haemocytes). Haemocytes respond to a variety of micro-organisms, but their role in virus replication and dissemination has not been described. To look for a potential haemocyte tropism for an arbovirus, a Sindbis virus was injected intrathoracically into four species of mosquito. Virus infects haemocytes as early as 6 h post injection (p.i.) and infection was evident in these cells for as long as 4 days p.i. More than 90 % of haemocytes were infected, most often the phagocytic granulocytes. Virus titres in the haemolymph increased from 24 h p.i. through 60 h p.i. Similar results were found when Aedes aegypti mosquitoes were injected with orally infectious Sindbis. These data prove that an arbovirus infects, and replicates in, haemocytes.

scholarly journals Zika Virus in Salivary Glands of Five Different Species of Wild-Caught Mosquitoes from Mexico

2017 ◽  
Author(s):  
Darwin Elizondo-Quiroga ◽  
Aarón. Medina-Sánchez ◽  
Jorge M. Sánchez-González ◽  
Kristen Allison Eckert ◽  
Erendira Villalobos-Sánchez ◽  
...  
Keyword(s):  
Cell Culture ◽  
Salivary Glands ◽  
Culex Quinquefasciatus ◽  
Blood Meal ◽  
Zika Virus ◽  
Mosquito Species ◽  
Body Parts ◽  
Male Mosquitoes

AbstractZika virus (ZIKV) is a mosquito-borne virus and Aedes agypti has been mentioned as the main vector of the disease. Other mosquito species in the Aedes and Culex genera have been suggested to have the potential for being competent vectors, based on experimental exposition of mosquitoes to an infectious blood meal containing ZIKV. Here, we report the isolation in cell culture of ZIKV from different body parts of wild-caught female mosquitoes (Ae. aegypti, Ae. vexans, Culex quinquefasciatus, Cx. coronator, and Cx. tarsalis) and whole male mosquitoes (Ae. aegypti and Cx. quinquefasciatus) in Mexico. Importantly, the virus was isolated from the salivary glands of all of these mosquitoes, strongly suggesting that these species are potential vectors for ZIKV.

scholarly journals Zika virus replication in the mosquito Culex quinquefasciatus in Brazil

2016 ◽  
Author(s):  
D. R. D. Guedes ◽  
M. H. S. Paiva ◽  
M. M. A. Donato ◽  
P. P. Barbosa ◽  
L. Krokovsky ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Salivary Glands ◽  
Virus Replication ◽  
Culex Quinquefasciatus ◽  
Zika Virus ◽  
Neurological Disorders ◽  
Urban Areas ◽  
Mosquito Species ◽  
Mosquito Bite ◽  
Vectorial Competence

AbstractZika virus (ZIKV) is a flavivirus that has recently been associated with increased incidence of neonatal microcephaly and other neurological disorders. The virus is primarily transmitted by mosquito bite, although other routes of infection have been implicated in some cases. The Aedes aegypti mosquito is considered to be the main vector to humans worldwide, but there is evidence of other mosquito species, including Culex quinquefasciatus, playing a role in the Brazilian outbreak. To test this hypothesis, we experimentally compared the vectorial competence of laboratory-reared A. aegypti and C. quinquefasciatus. We found ZIKV in the midgut, salivary glands, and saliva of artificially fed C. quinquefasciatus. Additionally, we collected ZIKV-infected C. quinquefasciatus from urban areas of high microcephaly incidence in Recife, Brazil. Take into account; these findings indicate that there may be a wider range of vectors for ZIKV than anticipated.

scholarly journals Heterogeneity of midgut cells and their differential responses to blood meal ingestion by the mosquito, Aedes aegypti

2020 ◽  
Author(s):  
Yingjun Cui ◽  
Alexander W.E. Franz
Keyword(s):  
Aedes Aegypti ◽  
Blood Meal ◽  
Mosquito Species ◽  
Cell Types ◽  
Blood Feeding ◽  
Nutrient Absorption ◽  
Cell Type ◽  
Blood Digestion ◽  
Mosquito Midgut ◽  
Meal Ingestion

AbstractMosquitoes are the most notorious hematophagous insects and due to their blood feeding behavior and genetic compatibility, numerous mosquito species are highly efficient vectors for certain human pathogenic parasites and viruses. The mosquito midgut is the principal organ of blood meal digestion and nutrient absorption. It is also the initial site of infection with blood meal acquired parasites and viruses. We conducted an analysis based on single-nucleus RNA sequencing (snRNA-Seq) to assess the cellular diversity of the midgut and how individual cells respond to blood meal ingestion to facilitate its digestion. Our study revealed the presence of 20 distinguishable cell-type clusters in the female midgut of Aedes aegypti. The identified cell types included intestinal stem cell (ISC), enteroblasts (EB), differentiating EB (dEB), enteroendocrine cells (EE), enterocytes (EC), EC-like cells, cardia cells, and visceral muscle (VM) cells. Blood meal ingestion dramatically changed the overall midgut cell type composition, profoundly increasing the proportions of ISC and three EC/EC like clusters. In addition, transcriptional profiles of all cell types were strongly affected while genes involved in various metabolic processes were significantly upregulated. Our study provides a basis for further physiological and molecular studies on blood digestion, nutrient absorption, and cellular homeostasis in the mosquito midgut.

SOME FUNCTIONS OF THE SALIVARY GLANDS OF MOSQUITOES AND OTHER BLOOD-FEEDING INSECTS

1964 ◽  
Vol 42 (1) ◽  
pp. 113-120 ◽  
Author(s):  
Anne Hudson
Keyword(s):  
Salivary Gland ◽  
Aedes Aegypti ◽  
Salivary Glands ◽  
Blood Meal ◽  
Blood Feeding ◽  
Gut Contents

Tests for anticoagulating, agglutinating, and lytic factors were performed on the gut contents of blood engorged specimens and on the salivary gland homogenates of several species of mosquitoes and other blood-feeding insects. The results suggest that these factors are commonly present in the salivary glands but may vary in concentration with the species. The anticoagulin was absent in female Aedes aegypti whose salivary ducts had been cut; some of the duct-cut insects had difficulty in probing, but were able to produce viable eggs and to feed again. The utilization of the blood meal in the absence of saliva is discussed.

scholarly journals Starvation at the larval stage increases the vector competence of Aedes aegypti females for Zika virus

2021 ◽  
Vol 15 (11) ◽  
pp. e0010003
Author(s):  
Christie S. Herd ◽  
DeAna G. Grant ◽  
Jingyi Lin ◽  
Alexander W. E. Franz
Keyword(s):  
Aedes Aegypti ◽  
Salivary Glands ◽  
Blood Meal ◽  
Zika Virus ◽  
Vector Competence ◽  
Transmission Cycle ◽  
Physical Evidence ◽  
Transmission Electron ◽  
Primary Vector ◽  
Blood Meal Digestion

Aedes aegypti is the primary vector of Zika virus (ZIKV), a flavivirus which typically presents itself as febrile-like symptoms in humans but can also cause neurological and pregnancy complications. The transmission cycle of mosquito-borne arboviruses such as ZIKV requires that various key tissues in the female mosquito including the salivary glands get productively infected with the virus before the mosquito can transmit the virus to another vertebrate host. Following ingestion of a viremic blood-meal from a vertebrate, ZIKV initially infects the midgut epithelium before exiting the midgut after blood-meal digestion to disseminate to secondary tissues including the salivary glands. Here we investigated whether smaller Ae. aegypti females resulting from food deprivation as larvae exhibited an altered vector competence for blood-meal acquired ZIKV relative to larger mosquitoes. Midguts from small ‘Starve’ and large ‘Control’ Ae. aegypti were dissected to visualize by transmission electron microscopy (TEM) the midgut basal lamina (BL) as physical evidence for the midgut escape barrier showing Starve mosquitoes with a significantly thinner midgut BL than Control mosquitoes at two timepoints. ZIKV replication was inhibited in Starve mosquitoes following intrathoracic injection of virus, however, Starve mosquitoes exhibited a significantly higher midgut escape and population dissemination rate at 9 days post-infection (dpi) via blood-meal, with more virus present in saliva and head tissue than Control by 10 dpi and 14 dpi, respectively. These results indicate that Ae. aegypti developing under stressful conditions potentially exhibit higher midgut infection and dissemination rates for ZIKV as adults, Thus, variation in food intake as larvae is potentially a source for variable vector competence levels of the emerged adults for the virus.

A Simple PCR Assay for Discrimination of Dengue Vectors from Nsukka LGA, Nigeria

2020 ◽  
Vol 10 (1) ◽  
pp. 67-77
Author(s):  
Amos Watentena ◽  
Ikem Chris Okoye ◽  
Ikechukwu Eugene Onah ◽  
Onwude Cosmas Ogbonnaya ◽  
Emmanuel Ogudu
Keyword(s):  
Aedes Aegypti ◽  
Aedes Albopictus ◽  
Mosquito Species ◽  
Public Health Problem ◽  
Major Public Health Problem ◽  
Mosquito Vector ◽  
Aedes Mosquitoes ◽  
Allele Specific ◽  
Arboviral Diseases ◽  
Dengue Vectors

Mosquitoes of Aedes species are vectors of several arboviral diseases which continue to be a major public health problem in Nigeria. This study among other things, morphologically identified Aedes mosquitoes collected from Nsukka LGA and used an allele specific PCR amplification for discrimination of dengue vectors. Larval sampling, BG-sentinel traps and modified human landing catches were used for mosquito sampling in two selected autonomous communities of Nsukka LGA (Nsukka and Obimo). A total of 124 Aedes mosquitoes consisting of five (5) different species were collected from April to June, 2019 in a cross-sectional study that covered 126 households, under 76 distinct geographical coordinates. Larvae was mainly collected from plastic containers 73% (n=224), metallic containers 14% (n=43), earthen pots 9% (n=29) and used car tyres 3% (n=9), reared to adult stage 69.35% (n=86), and all mosquitoes were identified using standard morphological keys. Five (5) Aedes mosquito species were captured; Aedes aegypti 83(66.94%), Aedes albopictus 33(26.61%), Aedes simpsoni (4.48%), Aedes luteocephalus (≤1%) and Aedes vittatus (≤1%). Nsukka autonomous community had higher species diversity than Obimo. Allele specific amplification confirmed dengue vectors, Aedes aegypti and Aedes albopictus species on a 2% agarose gel. Since the most recent re-emergence of arboviral diseases is closely associated with Aedes species, findings of this study, therefore, give further evidence about the presence of potential arboviral vectors in Nigeria and describe the role of a simple PCR in discriminating some. Further entomological studies should integrate PCR assays in mosquito vector surveillance.

scholarly journals Transmission Potential of Zika Virus by Aedes aegypti (Diptera: Culicidae) and Ae. mediovittatus (Diptera: Culicidae) Populations From Puerto Rico

2021 ◽  
Author(s):  
Rebecca A Zimler ◽  
Donald A Yee ◽  
Barry W Alto
Keyword(s):  
Puerto Rico ◽  
Aedes Aegypti ◽  
Zika Virus ◽  
Mosquito Species ◽  
The United States ◽  
Infection Rates ◽  
Transmission Potential ◽  
Transmission Rates ◽  
Higher Doses ◽  
Local Transmission

Abstract Recurrence of local transmission of Zika virus in Puerto Rico is a major public health risk to the United States, where mosquitoes Aedes aegypti (Linnaeus) and Aedes mediovittatus (Coquillett) are abundant. To determine the extent to which Ae. mediovittatus are capable of transmitting Zika virus and the influence of viremia, we evaluated infection and transmission in Ae. mediovittatus and Ae. aegypti from Puerto Rico using serial dilutions of infectious blood. Higher doses of infectious blood resulted in greater infection rates in both mosquitoes. Aedes aegypti females were up to twice as susceptible to infection than Ae. mediovittatus, indicating a more effective midgut infection barrier in the latter mosquito species. Aedes aegypti exhibited higher disseminated infection (40–95%) than Ae. mediovittatus (<5%), suggesting a substantial midgut escape barrier in Ae. mediovittatus. For Ae. aegypti, transmission rates were low over a range of doses of Zika virus ingested, suggesting substantial salivary gland barriers.

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