Immune intervention against blood-feeding insects

1996 ◽  
pp. 323-344 ◽  
Author(s):  
P. Willadsen ◽  
P. F. Billingsley
Keyword(s):  
Blood Feeding ◽  
Immune Intervention

Hemolysis of erythrocytes by the hemolytic system from the blood-feeding stable fly, Stomoxys calcitrans

1992 ◽  
Vol 50 (1) ◽  
pp. 690-691
Author(s):  
H. J. Kirch ◽  
G. Spates ◽  
R. Droleskey ◽  
W.J. Kloft ◽  
J.R. DeLoach
Keyword(s):  
Blood Feeding ◽  
Stomoxys Calcitrans ◽  
Stable Fly ◽  
Digestive Physiology ◽  
Transmission Electron ◽  
Erythrocyte Lysis ◽  
Mammalian Blood ◽  
Bovine Erythrocytes ◽  
Potential Tool

Blood feeding insects have to rely on the protein content of mammalian blood to insure reproduction. A substantial quantity of protein is provided by hemoglobin present in erythrocytes. Access to hemoglobin is accomplished only via erythrocyte lysis. It has been shown that midgut homogenates from the blood feeding stable fly, Stomoxys calcitrans, contain free fatty acids and it was proposed that these detergent-like compounds play a major role as hemolysins in the digestive physiology of this species. More recently sphingomyelinase activity was detected in midgut preparations of this fly, which would provide a potential tool for the enzymatic cleavage of the erythrocyte's membrane sphingomyelin. The action of specific hemolytic factors should affect the erythrocyte's morphology. The shape of bovine erythrocytes undergoing in vitro hemolysis by crude midgut homogenates from the stable fly was examined by scanning and transmission electron microscopy.

Medical Therapeutics Derived from Leeches (Phy. Annelida; Cl. Hirudinea)

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Christopher Everett Warren Clarke
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Heart Attack ◽  
Blood Feeding ◽  
Vascular Trauma ◽  
Biological Molecules ◽  
Future Treatment ◽  
Medical Therapeutics

Of all blood feeding invertebrates, few are more notorious than leeches. Throughout their existence as ectoparasites, leeches have evolved to release biological molecules in their saliva that act to counter the responses of the prey’s body to vascular trauma. Inadvertently, these very molecules have been used by humans for centuries for medicinal purposes; however, it is only recently that their cellular action has been elucidated. As a result, these compounds have been isolated and mass produced to treat a wide variety of conditions ranging from heart attack to Alzheimer’s disease and continued work suggests that these isolates will be an important future treatment for metastasis.

scholarly journals Tick Ecdysteroid Hormone, Global Microbiota/Rickettsia Signaling in the Ovary versus Carcass during Vitellogenesis in Part-Fed (Virgin) American Dog Ticks, Dermacentor variabilis

2021 ◽  
Vol 9 (6) ◽  
pp. 1242
Author(s):  
Loganathan Ponnusamy ◽  
Haley Sutton ◽  
Robert D. Mitchell ◽  
Daniel E. Sonenshine ◽  
Charles S. Apperson ◽  
...  
Keyword(s):  
Hormonal Regulation ◽  
Natural Populations ◽  
Blood Feeding ◽  
Dermacentor Variabilis ◽  
Transovarial Transmission ◽  
Rickettsia Species ◽  
Adult Females ◽  
Dog Tick ◽  
Total Bacteria

The transovarial transmission of tick-borne bacterial pathogens is an important mechanism for their maintenance in natural populations and transmission, causing disease in humans and animals. The mechanism for this transmission and the possible role of tick hormones facilitating this process have never been studied. Injections of physiological levels of the tick hormone, 20-hydroxyecdysone (20E), into part-fed (virgin) adult females of the American dog tick, Dermacentor variabilis, attached to the host caused a reduction in density of Rickettsia montanensis in the carcass and an increase in the ovaries compared to buffer-injected controls. This injection initiates yolk protein synthesis and uptake by the eggs but has no effect on blood feeding. Francisella sp. and R. montanensis were the predominant bacteria based on the proportionality in the carcass and ovary. The total bacteria load increased in the carcass and ovaries, and bacteria in the genus Pseudomonas increased in the carcass after the 20E injection. The mechanism of how the Rickettsia species respond to changes in tick hormonal regulation needs further investigation. Multiple possible mechanisms for the proliferation of R. montanensis in the ovaries are proposed.

scholarly journals Overexpression of Activated AMPK in the Anopheles stephensi Midgut Impacts Mosquito Metabolism, Reproduction and Plasmodium Resistance

Genes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 119
Author(s):  
Chioma Oringanje ◽  
Lillian R. Delacruz ◽  
Yunan Han ◽  
Shirley Luckhart ◽  
Michael A. Riehle
Keyword(s):  
Egg Production ◽  
Anopheles Stephensi ◽  
Mitochondrial Dynamics ◽  
Adult Life ◽  
Blood Feeding ◽  
Pathogen Resistance ◽  
Α Subunit ◽  
Significant Difference ◽  
Transgenic Lines ◽  
Ampk Activity

Mitochondrial integrity and homeostasis in the midgut are key factors controlling mosquito fitness and anti-pathogen resistance. Targeting genes that regulate mitochondrial dynamics represents a potential strategy for limiting mosquito-borne diseases. AMP-activated protein kinase (AMPK) is a key cellular energy sensor found in nearly all eukaryotic cells. When activated, AMPK inhibits anabolic pathways that consume ATP and activates catabolic processes that synthesize ATP. In this study, we overexpressed a truncated and constitutively active α-subunit of AMPK under the control of the midgut-specific carboxypeptidase promotor in the midgut of female Anopheles stephensi. As expected, AMPK overexpression in homozygous transgenic mosquitoes was associated with changes in nutrient storage and metabolism, decreasing glycogen levels at 24 h post-blood feeding when transgene expression was maximal, and concurrently increasing circulating trehalose at the same time point. When transgenic lines were challenged with Plasmodium falciparum, we observed a significant decrease in the prevalence and intensity of infection relative to wild type controls. Surprisingly, we did not observe a significant difference in the survival of adult mosquitoes fed either sugar only or both sugar and bloodmeals throughout adult life. This may be due to the limited period that the transgene was activated before homeostasis was restored. However, we did observe a significant decrease in egg production, suggesting that manipulation of AMPK activity in the mosquito midgut resulted in the re-allocation of resources away from egg production. In summary, this work identifies midgut AMPK activity as an important regulator of metabolism, reproduction, and innate immunity in An. stephensi, a highly invasive and important malaria vector species.

Identification of Bloodmeals from Sand Flies (Diptera: Psychodidae) Collected in the Parque Nacional do Viruá, State of Roraima, Brazil

2021 ◽  
Author(s):  
Bruno Leite Rodrigues ◽  
Glaucilene da Silva Costa ◽  
Paloma Helena Fernandes Shimabukuro
Keyword(s):  
Blood Feeding ◽  
Sand Flies ◽  
Feeding Preferences ◽  
Light Traps ◽  
Dasypus Novemcinctus ◽  
Search Tool ◽  
Vertebrate Hosts ◽  
Host Blood ◽  
Clustering Pattern ◽  
Species Being

Abstract The transmission of pathogens that cause leishmaniases occurs by the bite of female sand flies (Diptera: Psychodidae) in their vertebrate hosts, which makes the identification of their bloodmeal sources an important step for the control and epidemiology of these diseases. In Brazil, the state of Roraima has a great diversity of sand flies, vertebrate hosts, and protozoan Leishmania, but little is known about the host blood-feeding preferences of sand flies. Thus, we evaluated the bloodmeal sources of sand flies collected from their sylvatic habitats in Parque Nacional do Viruá, Roraima. Fieldwork was carried-out between 13th and 18th August 2019 using CDC light traps. Sand flies were slide-mounted and morphologically identified using the head and last segments of the abdomen. Engorged females had their DNA extracted, followed by amplification and sequencing of the cytochrome b (cytb) molecular marker for vertebrates. Sequences were analyzed and compared with those from GenBank using the BLASTn search tool, in addition to the reconstruction of a phylogenetic tree to demonstrate the clustering pattern of these sequences. A total of 1,209 sand flies were identified, comprising 20 species, in which the most abundant were Psychodopygus ayrozai (Barretto and Coutinho) (42.10%) and Psychodopygus chagasi (Costa Lima) (26.22%). Bloodmeal source identification was successfully performed for 34 sand flies, that confirm four vertebrate species, being the most abundant the armadillo Dasypus novemcinctus Linnaeus, 1758 (Cingulata: Dasypodidae).

scholarly journals Efficacy of interceptor® G2, a long-lasting insecticide mixture net treated with chlorfenapyr and alpha-cypermethrin against Anopheles funestus: experimental hut trials in north-eastern Tanzania

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Patrick K. Tungu ◽  
Elisante Michael ◽  
Wema Sudi ◽  
William W. Kisinza ◽  
Mark Rowland
Keyword(s):  
Pyrethroid Resistance ◽  
Meta Analysis ◽  
Anopheles Funestus ◽  
Blood Feeding ◽  
Significant Loss ◽  
World Health ◽  
Cross Resistance ◽  
Personal Protection ◽  
Experimental Hut ◽  
Field Evidence

Abstract Background The effectiveness of long-lasting insecticidal nets (LLIN), the primary method for preventing malaria in Africa, is compromised by evolution and spread of pyrethroid resistance. Further gains require new insecticides with novel modes of action. Chlorfenapyr is a pyrrole insecticide that disrupts mitochrondrial function and confers no cross-resistance to neurotoxic insecticides. Interceptor® G2 LN (IG2) is an insecticide-mixture LLIN, which combines wash-resistant formulations of chlorfenapyr and the pyrethroid alpha-cypermethrin. The objective was to determine IG2 efficacy under controlled household-like conditions for personal protection and control of wild, pyrethroid-resistant Anopheles funestus mosquitoes. Methods Experimental hut trials tested IG2 efficacy against two positive controls—a chlorfenapyr-treated net and a standard alpha-cypermethrin LLIN, Interceptor LN (IG1)—consistent with World Health Organization (WHO) evaluation guidelines. Mosquito mortality, blood-feeding inhibition, personal protection, repellency and insecticide-induced exiting were recorded after zero and 20 washing cycles. The trial was repeated and analysed using multivariate and meta-analysis. Results In the two trials held in NE Tanzania, An. funestus mortality was 2.27 (risk ratio 95% CI 1.13–4.56) times greater with unwashed Interceptor G2 than with unwashed Interceptor LN (p = 0.012). There was no significant loss in mortality with IG2 between 0 and 20 washes (1.04, 95% CI 0.83–1.30, p = 0.73). Comparison with chlorfenapyr treated net indicated that most mortality was induced by the chlorfenapyr component of IG2 (0.96, CI 0.74–1.23), while comparison with Interceptor LN indicated blood-feeding was inhibited by the pyrethroid component of IG2 (IG2: 0.70, CI 0.44–1.11 vs IG1: 0.61, CI 0.39–0.97). Both insecticide components contributed to exiting from the huts but the contributions were heterogeneous between trials (heterogeneity Q = 36, P = 0.02). WHO susceptibility tests with pyrethroid papers recorded 44% survival in An. funestus. Conclusions The high mortality recorded by IG2 against pyrethroid-resistant An. funestus provides first field evidence of high efficacy against this primary, anthropophilic, malaria vector.

scholarly journals Modulation of odour-guided behaviour in mosquitoes

2021 ◽  
Vol 383 (1) ◽  
pp. 195-206
Author(s):  
Sharon R. Hill ◽  
Rickard Ignell
Keyword(s):  
Functional Genomics ◽  
Life Stage ◽  
Blood Feeding ◽  
Model Systems ◽  
Extrinsic Factors ◽  
Intrinsic Factors ◽  
Host Seeking ◽  
Enhancing Resources ◽  
Maturation Age ◽  
Behavioural Repertoire

AbstractMosquitoes are emerging as model systems with which to study innate behaviours through neuroethology and functional genomics. Decades of work on these disease vectors have provided a solid behavioural framework describing the distinct repertoire of predominantly odour-mediated behaviours of female mosquitoes, and their dependence on life stage (intrinsic factors) and environmental cues (extrinsic factors). The purpose of this review is to provide an overview of how intrinsic factors, including adult maturation, age, nutritional status, and infection, affect the attraction to plants and feeding on plant fluids, host seeking, blood feeding, supplemental feeding behaviours, pre-oviposition behaviour, and oviposition in female mosquitoes. With the technological advancements in the recent two decades, we have gained a better understanding of which volatile organic compounds are used by mosquitoes to recognise and discriminate among various fitness-enhancing resources, and characterised their neural and molecular correlates. In this review, we present the state of the art of the peripheral olfactory system as described by the neural physiology, functional genomics, and genetics underlying the demonstrated changes in the behavioural repertoire in female mosquitoes. The review is meant as a summary introduction to the current conceptual thinking in the field.

Sign in / Sign up

Export Citation Format

Share Document