Bloodmeal digestion by strains of Anopheles stephensi Liston (Diptera: Culicidae) of differing susceptibility to Plasmodium falciparum

Parasitology ◽  
1990 ◽  
Vol 101 (2) ◽  
pp. 193-200 ◽  
Author(s):  
A. M. Feldmann ◽  
P. F. Billingsley ◽  
E. Savelkoul
Keyword(s):  
Plasmodium Falciparum ◽  
Anopheles Stephensi ◽  
Feeding Activity ◽  
Parasite Development ◽  
Aminopeptidase Activity ◽  
Total Protein Content ◽  
Trypsin Activity ◽  
Blood Digestion ◽  
Susceptibility To Infection ◽  
Post Feeding

Blood digestion was studied in strains of Anopheles stephensi which had been genetically selected for either refractoriness or susceptibility to infection by Plasmodium falciparum. Females of the refractory Pb3—9a strain ingested more blood than selected (Sda-500) and unselected (Punjab) susceptible females and began to degrade the haemoglobin soon after feeding. In susceptible females, haemoglobin degradation started only after a significant post-feeding lag period. Total protein content of the midgut after the bloodmeal was correspondingly higher for refractory than for susceptible females, but absolute and relative rates of protein degradation were not significantly different between the different mosquito strains. Bloodmeal induction of midgut trypsin activity and the maximal trypsin activity were the same for the different strains. The residual aminopeptidase activity and its relative post-feeding activity (enzyme units per midgut) were significantly higher in refractory females. However, when converting to specific aminopeptidase activity, no differences between strains were evident. The results indicate that both the early initiation of haemoglobin degradation and higher aminopeptidase activity in the Pb3—9a refractory strain are important in the limitation of parasite development within the mosquito midgut, whereas trypsin plays no role in this process.

Plasmodium falciparum: Stage-Specific Ribosomal RNA as a Potential Target for Monitoring Parasite Development in Anopheles stephensi

1993 ◽  
Vol 76 (1) ◽  
pp. 32-38 ◽  
Author(s):  
J. Li ◽  
R.A. Wirtz ◽  
I. Schneider ◽  
O.V. Muratova ◽  
T.F. Mccutchan ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Ribosomal Rna ◽  
Anopheles Stephensi ◽  
Parasite Development ◽  
Potential Target

scholarly journals A mating-induced reproductive gene promotes Anopheles tolerance to Plasmodium falciparum infection

2020 ◽  
Author(s):  
Perrine Marcenac ◽  
W. Robert Shaw ◽  
Evdoxia G. Kakani ◽  
Sara N. Mitchell ◽  
Adam South ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Anopheles Gambiae ◽  
Anopheles Stephensi ◽  
Steroid Hormone ◽  
Parasite Development ◽  
Anopheles Coluzzii ◽  
Reproductive Costs ◽  
Fitness Costs ◽  
Mating Status ◽  
Human Malaria

AbstractAnopheles mosquitoes have transmitted Plasmodium parasites for millions of years, yet it remains unclear whether they suffer fitness costs to infection. Here we report that the fecundity of virgin and mated females of two important vectors—Anopheles gambiae and Anopheles stephensi—is not affected by infection with Plasmodium falciparum, demonstrating that these human malaria parasites do not inflict reproductive costs to their natural mosquito hosts. Additionally, parasite development is not impacted by mating status. However, in field studies using different P. falciparum isolates in Anopheles coluzzii, we find that Mating-Induced Stimulator of Oogenesis (MISO), a female reproductive gene strongly induced after mating by the sexual transfer of the steroid hormone 20-hydroxyecdysone (20E), protects females from incurring fecundity costs to infection. MISO-silenced females produce fewer eggs as they become increasingly infected with P. falciparum, while parasite development is not impacted by this gene silencing. Interestingly, previous work had shown that sexual transfer of 20E has specifically evolved in Cellia species of the Anopheles genus, driving the co-adaptation of MISO. Our data therefore suggest that evolution of male-female sexual interactions may have promoted Anopheles tolerance to P. falciparum infection in the Cellia subgenus, which comprises the most important malaria vectors.Author summaryPlasmodium falciparum, the deadliest form of human malaria, is transmitted when female Anopheles mosquitoes bite people and take a blood meal in order to develop eggs. To date, it is still poorly understood whether Anopheles mosquitoes that get infected with P. falciparum suffer fitness costs. Here, we find that the number of eggs produced by Anopheles gambiae and Anopheles stephensi females is not affected by P. falciparum infection, and that the mating status of the mosquitoes does not impact the parasite. However, in field experiments infecting a related species, Anopheles coluzzii, with P. falciparum using blood from donors in Burkina Faso, we find that interfering with the expression of a gene normally triggered by the sexual transfer of the steroid hormone 20-hydroxyecdysone induces increasing costs to egg development as females become more infected with P. falciparum, with no impacts on the parasite. The results of our study suggest that pathways triggered by mating may help Anopheles prevent reproductive costs associated with P. falciparum infection, providing new insights into evolutionary strategies adopted by anophelines in the face of a longstanding association with Plasmodium parasites.

scholarly journals Exploring the lower thermal limits for transmission of human malaria, Plasmodium falciparum

2019 ◽  
Author(s):  
Jessica L. Waite ◽  
Eunho Suh ◽  
Penelope A. Lynch ◽  
Matthew B. Thomas
Keyword(s):  
Plasmodium Falciparum ◽  
Anopheles Stephensi ◽  
Parasite Development ◽  
Temperature Dependent ◽  
Single Degree ◽  
Complete Development ◽  
Thermal Limits ◽  
Degree Day ◽  
Extrinsic Incubation Period ◽  
Impacts Of Climate Change

AbstractThe rate of malaria transmission is strongly determined by parasite development time in the mosquito, known as the extrinsic incubation period (EIP), since the quicker parasites develop, the greater the chance that the vector will survive long enough for the parasite to complete development and be transmitted. EIP is known to be temperature dependent but this relationship is surprisingly poorly characterized. There is a single degree-day model for EIP of Plasmodium falciparum that derives from a limited number of poorly controlled studies conducted almost a century ago. Here, we show that the established degree-day model greatly underestimates the rate of development of P. falciparum in both Anopheles stephensi and An. gambiae mosquitoes at temperatures in the range of 17-20°C. We also show that realistic daily temperature fluctuation further speeds parasite development. These novel results challenge one of the longest standing models in malaria biology and have potentially important implications for understanding the impacts of climate change.

Blood digestion in the mosquito, Anopheles stephensi: the effects of Plasmodium yoelii nigeriensis on midgut enzyme activities

Parasitology ◽  
1999 ◽  
Vol 119 (6) ◽  
pp. 535-541 ◽  
Author(s):  
N. JAHAN ◽  
P. T. DOCHERTY ◽  
P. F. BILLINGSLEY ◽  
H. HURD
Keyword(s):  
Total Protein ◽  
Enzyme Activities ◽  
Egg Production ◽  
Anopheles Stephensi ◽  
Plasmodium Yoelii ◽  
Aminopeptidase Activity ◽  
Gonotrophic Cycle ◽  
Protein Digestion ◽  
Reciprocal Effect ◽  
Blood Digestion

Midgut proteases contribute to the success or failure of Plasmodium infection of the mosquito. This paper examines the reciprocal effect of Plasmodium yoelii nigeriensis on midgut trypsin, chymotrypsin, aminopeptidase and carboxypeptidase in the mosquito Anopheles stephensi. The total protein ingested and the rate of protein digestion were unaffected by the parasite, but more protein was ingested at the first than the second bloodmeal. All peptidases were unaffected by the presence of the parasite during the first gonotrophic cycle, when ookinetes were penetrating the midgut. In the second gonotrophic cycle, trypsin and chymotrypsin were unaffected by growing oocysts, but aminopeptidase activity was reduced in the midguts of infected mosquitoes. Chymotrypsin activity was depressed and aminopeptidase activity elevated during the second gonotrophic cycle. Plasmodium infection has a negligible effect on bloodmeal digestion and does not limit the availability of the protein for egg production. The significance of changes in aminopeptidase activity when oocysts are present is discussed.

scholarly journals A mating-induced reproductive gene promotes Anopheles tolerance to Plasmodium falciparum infection

2020 ◽  
Vol 16 (12) ◽  
pp. e1008908
Author(s):  
Perrine Marcenac ◽  
W. Robert Shaw ◽  
Evdoxia G. Kakani ◽  
Sara N. Mitchell ◽  
Adam South ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Anopheles Stephensi ◽  
Steroid Hormone ◽  
Field Studies ◽  
Falciparum Infection ◽  
Malaria Vectors ◽  
Parasite Development ◽  
Anopheles Coluzzii ◽  
Fitness Costs ◽  
Mating Status

Anopheles mosquitoes have transmitted Plasmodium parasites for millions of years, yet it remains unclear whether they suffer fitness costs to infection. Here we report that the fecundity of virgin and mated females of two important vectors—Anopheles gambiae and Anopheles stephensi—is not affected by infection with Plasmodium falciparum, demonstrating that these human malaria parasites do not inflict this reproductive cost on their natural mosquito hosts. Additionally, parasite development is not impacted by mating status. However, in field studies using different P. falciparum isolates in Anopheles coluzzii, we find that Mating-Induced Stimulator of Oogenesis (MISO), a female reproductive gene strongly induced after mating by the sexual transfer of the steroid hormone 20-hydroxyecdysone (20E), protects females from incurring fecundity costs to infection. MISO-silenced females produce fewer eggs as they become increasingly infected with P. falciparum, while parasite development is not impacted by this gene silencing. Interestingly, previous work had shown that sexual transfer of 20E has specifically evolved in Cellia species of the Anopheles genus, driving the co-adaptation of MISO. Our data therefore suggest that evolution of male-female sexual interactions may have promoted Anopheles tolerance to P. falciparum infection in the Cellia subgenus, which comprises the most important malaria vectors.

scholarly journals Roles for Two Aminopeptidases in Vacuolar Hemoglobin Catabolism in Plasmodium falciparum

2007 ◽  
Vol 282 (49) ◽  
pp. 35978-35987 ◽  
Author(s):  
Seema Dalal ◽  
Michael Klemba
Keyword(s):  
Amino Acids ◽  
Plasmodium Falciparum ◽  
Current Model ◽  
Food Vacuole ◽  
Peptide Transport ◽  
Parasite Development ◽  
Aminopeptidase Activity ◽  
Erythrocytic Cycle ◽  
The Impact

During the erythrocytic stage of its life cycle, the human malaria parasite Plasmodium falciparum catabolizes large quantities of host-cell hemoglobin in an acidic organelle, the food vacuole. A current model for the catabolism of globin-derived oligopeptides invokes peptide transport out of the food vacuole followed by hydrolysis to amino acids by cytosolic aminopeptidases. To test this model, we have examined the roles of four parasite aminopeptidases during the erythrocytic cycle. Localization of tagged aminopeptidases, coupled with biochemical analysis of enriched food vacuoles, revealed the presence of amino acid-generating pathways in the food vacuole as well as the cytosol. Based on the localization data and in vitro assays, we propose a specific role for one of the plasmodial enzymes, aminopeptidase P, in the catabolism of proline-containing peptides in both the vacuole and the cytosol. We establish an apparent requirement for three of the four aminopeptidases (including the two food vacuole enzymes) for efficient parasite proliferation. To gain insight into the impact of aminopeptidase inhibition on parasite development, we examined the effect of the presence of amino acids in the culture medium of the parasite on the toxicity of the aminopeptidase inhibitor bestatin. The ability of bestatin to block parasite replication was only slightly affected when 19 of 20 amino acids were withdrawn from the medium, indicating that exogenous amino acids cannot compensate for the loss of aminopeptidase activity. Together, these results support the development of aminopeptidase inhibitors as novel chemotherapeutics directed against malaria.

Partial characterization and post-feeding activity of midgut aminopeptidase in the human body louse,Pediculus humanus humanus

1998 ◽  
Vol 23 (4) ◽  
pp. 382-387 ◽  
Author(s):  
James O. Ochanda ◽  
Eva A. C. Oduor ◽  
Rachel Galun ◽  
Mabel O. Imbuga ◽  
Kosta Y. Mumcuoglu
Keyword(s):  
Human Body ◽  
Feeding Activity ◽  
Partial Characterization ◽  
Body Louse ◽  
Pediculus Humanus ◽  
Post Feeding ◽  
Human Body Louse

scholarly journals Stage-dependent effect of deferoxamine on growth of Plasmodium falciparum in vitro

Blood ◽  
1990 ◽  
Vol 76 (6) ◽  
pp. 1250-1255 ◽  
Author(s):  
S Whitehead ◽  
TE Peto
Keyword(s):  
Plasmodium Falciparum ◽  
Growth Inhibition ◽  
Antimalarial Activity ◽  
Clinical Malaria ◽  
Inhibitory Effect ◽  
Parasite Development ◽  
And Control ◽  
Speed Of Onset

Abstract Deferoxamine (DF) has antimalarial activity that can be demonstrated in vitro and in vivo. This study is designed to examine the speed of onset and stage dependency of growth inhibition by DF and to determine whether its antimalarial activity is cytostatic or cytocidal. Growth inhibition was assessed by suppression of hypoxanthine incorporation and differences in morphologic appearance between treated and control parasites. Using synchronized in vitro cultures of Plasmodium falciparum, growth inhibition by DF was detected within a single parasite cycle. Ring and nonpigmented trophozoite stages were sensitive to the inhibitory effect of DF but cytostatic antimalarial activity was suggested by evidence of parasite recovery in later cycles. However, profound growth inhibition, with no evidence of subsequent recovery, occurred when pigmented trophozoites and early schizonts were exposed to DF. At this stage in parasite development, the activity of DF was cytocidal and furthermore, the critical period of exposure may be as short as 6 hours. These observations suggest that iron chelators may have a role in the treatment of clinical malaria.

scholarly journals Optimization of Plasmodium vivax sporozoite production from Anopheles stephensi in South West India

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Ajeet Kumar Mohanty ◽  
Charles de Souza ◽  
Deepika Harjai ◽  
Prathamesh Ghavanalkar ◽  
Mezia Fernandes ◽  
...  
Keyword(s):  
South Asia ◽  
Plasmodium Vivax ◽  
Anopheles Stephensi ◽  
Parasite Development ◽  
Future Research ◽  
High Quality ◽  
Gametocyte Density ◽  
Feeding Experiments ◽  
South West ◽  
Membrane Feeding

Abstract Background Efforts to study the biology of Plasmodium vivax liver stages, particularly the latent hypnozoites, have been hampered by the limited availability of P. vivax sporozoites. Anopheles stephensi is a major urban malaria vector in Goa and elsewhere in South Asia. Using P. vivax patient blood samples, a series of standard membrane-feeding experiments were performed with An. stephensi under the US NIH International Center of Excellence for Malaria Research (ICEMR) for Malaria Evolution in South Asia (MESA). The goal was to understand the dynamics of parasite development in mosquitoes as well as the production of P. vivax sporozoites. To obtain a robust supply of P. vivax sporozoites, mosquito-rearing and mosquito membrane-feeding techniques were optimized, which are described here. Methods Membrane-feeding experiments were conducted using both wild and laboratory-colonized An. stephensi mosquitoes and patient-derived P. vivax collected at the Goa Medical College and Hospital. Parasite development to midgut oocysts and salivary gland sporozoites was assessed on days 7 and 14 post-feeding, respectively. The optimal conditions for mosquito rearing and feeding were evaluated to produce high-quality mosquitoes and to yield a high sporozoite rate, respectively. Results Laboratory-colonized mosquitoes could be starved for a shorter time before successful blood feeding compared with wild-caught mosquitoes. Optimizing the mosquito-rearing methods significantly increased mosquito survival. For mosquito feeding, replacing patient plasma with naïve serum increased sporozoite production > two-fold. With these changes, the sporozoite infection rate was high (> 85%) and resulted in an average of ~ 22,000 sporozoites per mosquito. Some mosquitoes reached up to 73,000 sporozoites. Sporozoite production could not be predicted from gametocyte density but could be predicted by measuring oocyst infection and oocyst load. Conclusions Optimized conditions for the production of high-quality P. vivax sporozoite-infected An. stephensi were established at a field site in South West India. This report describes techniques for producing a ready resource of P. vivax sporozoites. The improved protocols can help in future research on the biology of P. vivax liver stages, including hypnozoites, in India, as well as the development of anti-relapse interventions for vivax malaria.

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