scholarly journals Probe-based multiplex qPCR identifies bloodmeal hosts in Anopheles mosquitoes from Papua New Guinea

2019 ◽  
Author(s):  
John B Keven ◽  
Georgia Artzberger ◽  
Mary L. Gillies ◽  
Rex B. Mbewe ◽  
Edward D. Walker
Keyword(s):  
Quantitative Pcr ◽  
Nuclear Dna ◽  
Control Measures ◽  
Molecular Probe ◽  
Malaria Vectors ◽  
Anopheles Mosquitoes ◽  
Vertebrate Hosts ◽  
Host Blood ◽  
Blood Meals

Abstract Background: Determination of bloodmeal hosts in blood-fed female Anopheles mosquitoes is important for evaluating vectorial capacity of vector populations and assessing effectiveness of vector control measures. Sensitive molecular methods are needed to detect traces of host blood in mosquito samples, to differentiate hosts, and to detect mixed host blood meals. This paper describes a molecular probe-based quantitative PCR for identifying bloodmeal hosts in Anopheles malaria vectors from Papua New Guinea.Methods: TaqMan oligonucleotide probes targeting specific regions of mitochondrial or nuclear DNA of the three primary Anopheles bloodmeal hosts – humans, pigs and dogs – were incorporated into a multiplex, quantitative PCR which was optimized for sensitivity and specificity.Results: Amplification of serially diluted DNA showed that the quantitative PCR detected as low as 10-5 ng/μl of host DNA. Application to field-collected, blood-fed Anopheles showed that the quantitative PCR identified the vertebrate hosts for 335/375 (89%) of mosquitoes whereas only 104/188 (55%) of bloodmeal samples tested in a conventional PCR were identified. Of 188 blood-fed Anopheles that were analyzed in both PCR methods, 16 (8.5%) were identified as mixed bloodmeals by the quantitative PCR whereas only 3 (1.6%) were mixed bloodmeals by the conventional PCR.Conclusions: The multiplex quantitative PCR described here is sensitive at detecting low DNA concentration and mixed host DNA in samples and useful for bloodmeal analysis of field mosquitoes, in particular mixed-host bloodmeals.

scholarly journals Probe-based multiplex qPCR identifies bloodmeal hosts in Anopheles mosquitoes from Papua New Guinea

2020 ◽  
Author(s):  
John B Keven ◽  
Georgia Artzberger ◽  
Mary L. Gillies ◽  
Rex B. Mbewe ◽  
Edward D. Walker
Keyword(s):  
Papua New Guinea ◽  
Quantitative Pcr ◽  
Nuclear Dna ◽  
New Guinea ◽  
Control Measures ◽  
Molecular Probe ◽  
Malaria Vectors ◽  
Conventional Pcr ◽  
Anopheles Mosquitoes ◽  
Host Blood

Abstract Background: Determination of bloodmeal hosts in blood-fed female Anopheles mosquitoes is important for evaluating vectorial capacity of vector populations and assessing effectiveness of vector control measures. Sensitive molecular methods are needed to detect traces of host blood in mosquito samples, to differentiate hosts, and to detect mixed host blood meals. This paper describes a molecular probe-based quantitative PCR for identifying bloodmeal hosts in Anopheles malaria vectors from Papua New Guinea. Methods: TaqMan oligonucleotide probes targeting specific regions of mitochondrial or nuclear DNA of the three primary Anopheles bloodmeal hosts – humans, pigs and dogs – were incorporated into a multiplex, quantitative PCR which was optimized for sensitivity and specificity.Results: Amplification of serially diluted DNA showed that the quantitative PCR detected as low as 10-5 ng/μl of host DNA. Application to field-collected, blood-fed Anopheles showed that the quantitative PCR identified the vertebrate hosts for 335/375 (89%) of mosquitoes whereas only 104/188 (55%) of bloodmeal samples tested in a conventional PCR were identified. Of the 104 blood-fed Anopheles that were positive in both PCR methods, 16 (15.4%) were identified as mixed bloodmeals by the quantitative PCR whereas only 3 (2.9%) were mixed bloodmeals by the conventional PCR. Conclusions: The multiplex quantitative PCR described here is sensitive at detecting low DNA concentration and mixed host DNA in samples and useful for bloodmeal analysis of field mosquitoes, in particular mixed-host bloodmeals.

scholarly journals Probe-based multiplex qPCR identifies blood-meal hosts in Anopheles mosquitoes from Papua New Guinea

2020 ◽  
Author(s):  
John B Keven ◽  
Georgia Artzberger ◽  
Mary L. Gillies ◽  
Rex B. Mbewe ◽  
Edward D. Walker
Keyword(s):  
Papua New Guinea ◽  
Quantitative Pcr ◽  
Blood Meal ◽  
New Guinea ◽  
Molecular Probe ◽  
Conventional Pcr ◽  
Anopheles Mosquitoes ◽  
Mixed Blood ◽  
Host Blood ◽  
Blood Meals

Abstract Background: Determination of blood-meal hosts in blood-fed female Anopheles mosquitoes is important for evaluating vectorial capacity of vector populations and assessing effectiveness of vector control measures. Sensitive molecular methods are needed to detect traces of host blood in mosquito samples, to differentiate hosts, and to detect mixed host blood meals. This paper describes a molecular probe-based quantitative PCR for identifying blood-meal hosts in Anopheles malaria vectors from Papua New Guinea. Methods: TaqMan oligonucleotide probes targeting specific regions of mitochondrial or nuclear DNA of the three primary Anopheles blood-meal hosts, humans, pigs and dogs, were incorporated into a multiplex, quantitative PCR which was optimized for sensitivity and specificity. Results: Amplification of serially diluted DNA showed that the quantitative PCR detected as low as 10-5 ng/ml of host DNA. Application to field-collected, blood-fed Anopheles showed that the quantitative PCR identified the vertebrate hosts for 89% (335/375) of mosquitoes whereas only 55% (104/188) of blood-meal samples tested in a conventional PCR were identified. Of the 104 blood-fed Anopheles that were positive in both PCR methods, 16 (15.4%) were identified as mixed blood meals by the quantitative PCR whereas only 3 (2.9%) were mixed blood meals by the conventional PCR. Conclusions: The multiplex quantitative PCR described here is sensitive at detecting low DNA concentration and mixed host DNA in samples and useful for blood-meal analysis of field mosquitoes, in particular mixed-host blood meals.

FACTORS INFLUENCING THE PERFORMANCE OF THE PRECIPITIN TEST IN THE DETERMINATION OF BLOOD MEALS OF INSECTS

1952 ◽  
Vol 30 (4) ◽  
pp. 213-218 ◽  
Author(s):  
G. S. Eligh
Keyword(s):  
Adverse Effect ◽  
Liquid State ◽  
Factors Influencing ◽  
Precipitin Reaction ◽  
Precipitin Test ◽  
Host Blood ◽  
Blood Meals

Certain factors influence the performance of precipitin tests when the latter are used for detection of blood meals of biting flies. Antisera stored in a liquid state in a refrigerator generally show a decrease in titer with the passage of time. Aging appears to have an adverse effect on the avidity of an antiserum. Smears of blood-engorged mosquitoes prepared by smearing of the entire insect are satisfactory for testing by the precipitin reaction. A high-titered antiserum which can be diluted is desirable for detection of host blood in mosquitoes.

scholarly journals Biologically meaningful coverage indicators for eliminating malaria transmission

2012 ◽  
Vol 8 (5) ◽  
pp. 874-877 ◽  
Author(s):  
Samson S. Kiware ◽  
Nakul Chitnis ◽  
Gregor J. Devine ◽  
Sarah J. Moore ◽  
Silas Majambere ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Human Exposure ◽  
Optimal Strategies ◽  
Control Measures ◽  
Malaria Vectors ◽  
Two Dimensional ◽  
Front Line ◽  
High Coverage ◽  
Long Lasting Insecticidal Nets ◽  
Blood Meals

Mosquitoes, which evade contact with long-lasting insecticidal nets and indoor residual sprays, by feeding outdoors or upon animals, are primary malaria vectors in many tropical countries. They can also dominate residual transmission where high coverage of these front-line vector control measures is achieved. Complementary strategies, which extend insecticide coverage beyond houses and humans, are required to eliminate malaria transmission in most settings. The overwhelming diversity of the world's malaria transmission systems and optimal strategies for controlling them can be simply conceptualized and mapped across two-dimensional scenario space defined by the proportion of blood meals that vectors obtain from humans and the proportion of human exposure to them which occurs indoors.

scholarly journals Bioengineering of malaria vectors, anopheles mosquitoes (Diptera: Culicidae) as a control strategy: An overview

2019 ◽  
Vol 6 (12) ◽  
pp. 27-38
Author(s):  
Kayode David Ileke ◽  
Isaac Omotayo Olabimi
Keyword(s):  
Communicable Disease ◽  
Transmitted Disease ◽  
Indoor Residual Spraying ◽  
Control Measures ◽  
Malaria Vectors ◽  
Population Replacement ◽  
Anopheles Mosquitoes ◽  
Vector Population ◽  
Replacement Technique ◽  
Population Suppression

Disease in any form is undesirable in any human population. Malaria is a communicable disease that is vectored by female Anopheles mosquitoes. It is the leading vector transmitted disease in terms of the number of morbidity and mortality accounting for over 200 million cases annually. Several control measures have been employed by man over the years to control the vector which will in turn lead to the control of the diseases with the popular ones involving the use of insecticidal nets and indoor residual spraying of insecticides. However, these control measures have their various pitfalls. The use of genetically modified mosquitoes (GMMs) through bioengineering may be a promising method of reducing malaria vector population in our environment. This process involves population replacement technique (PRT) and population suppression techniques (PST). With proper integration of GMMs into the already existing control measures employed in the management of mosquitoes, a remarkable decrease in the prevalence of malaria is envisaged.

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).

Molecular characterization of plasmid-mediated quinolone resistance (PMQR) and ESBLs-producing Klebsiella pneumonia isolated from an Iranian teaching hospital

2021 ◽  
Author(s):  
Hamid Talebzadeh ◽  
Hamid Mellali ◽  
hamid solgi
Keyword(s):  
Teaching Hospital ◽  
Strong Association ◽  
Control Measures ◽  
Klebsiella Pneumonia ◽  
The Public ◽  
Isfahan Province ◽  
Clonal Distribution ◽  
Cross Transmission

Abstract Background The spread of plasmid-mediated multidrug resistance in Klebsiella pneumonia is a serious threat to the public health. We investigated the clinical characteristics and molecular epidemiology of K. pneumoniae isolated at a teaching hospital in Iran. Methods A total of 50 third-generation cephalosporins resistant K. pneumoniae strains were collected from patients’ clinical cultures. Antibiotic susceptibility testing and determination of MIC values for ceftazidime, cefotaxime and ciprofloxacin were performed. PCR and DNA sequencing were used to assess the presence of ESBL genes (blaCTX−M, blaTEM, blaSHV) and PMQR genes (qnrA, qnrB, qnrS, qepA, oqxA, oqxB and aac(6)-Ib-cr). Multilocus sequence typing (MLST) was performed on the strains to assess homology. Results Our results showed that the rates of resistance to all of antibiotics is high. All 50 K. pneumoniae strains harboured at least one of the ESBL resistance determinants. The blaCTX−M−15 gene was the major ESBLs determinant found in K. pneumoniae (88%; 44/50). PMQR was detected in 96% of the isolates and aac(6′)-Ib-cr was the most common (78% 39/50) followed by oqxA 36 (72%), oqxB 34 (68%), qnrS 20 (40%), qnrB 14 (28%) and qepA 1 (2%). MLST identified seven sequence types (STs), with the most common being ST11 (19/39). There was a strong association between PMQR genes (especially aac(6′)-Ib-cr) and ESBL genes. Conclusion The widespread detection of ESBLs-producing K. pneumoniae that co-carried PMQR determinants has become a threat to the treatment of infections in Isfahan Province of center Iran. Our findings suggest that K. pneumoniae ST11 and ST893 has a clonal distribution in our hospital. Therefore, this study highlighted the crucial need for implementing strict control measures to prevent cross transmission of these endemic clones.

scholarly journals Salivary complement inhibitors from mosquitoes: Structure and mechanism of action

2020 ◽  
pp. jbc.RA120.015230
Author(s):  
Ethan C Strayer ◽  
Stephen Lu ◽  
Jose M. Ribeiro ◽  
John F. Andersen
Keyword(s):  
Functional Role ◽  
Alternative Pathway ◽  
Malaria Vectors ◽  
Salivary Proteins ◽  
Plasma Extravasation ◽  
Lower Affinity ◽  
Anopheles Mosquitoes ◽  
Highly Active ◽  
Complement Inhibitors ◽  
Insight Into

Inhibition of the alternative pathway (AP) of complement by saliva from Anopheles mosquitoes facilitates feeding by blocking production of the anaphylatoxins C3a and C5a which activate mast cells leading to plasma extravasation, pain and itching. We have previously shown that albicin, a member of the SG7 protein family from An. albimanus blocks the AP by binding to and inhibiting the function of the C3 convertase, C3bBb. Here we show that SG7.AF, the albicin homolog from An. freeborni, has a similar potency to albicin but is more active in the presence of properdin, a plasma protein that acts to stabilize C3bBb. Conversely, albicin is highly active in the absence or presence of properdin. Albicin and SG7.AF stabilize the C3bBb complex in a form that accumulates on surface plasmon resonance (SPR) surfaces coated with properdin but SG7.AF binds with lower affinity than albicin. Albicin induces oligomerization of the complex in solution, suggesting that it is oligomerization that leads to stabilization on SPR surfaces. Anophensin, the albicin ortholog from An. stephensi, is only weakly active as an inhibitor of the AP, suggesting that the SG7 family may play a different functional role in this species and other species of the subgenus Cellia, containing the major malaria vectors in Africa and Asia. Crystal structures of albicin and SG7.AF reveal a novel four-helix bundle arrangement, that is stabilized by a N-terminal hydrogen bonding network. These structures provide insight into the SG7 family and related mosquito salivary proteins including the platelet-inhibitory 30kDa family.

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