Spatial Bet Hedging in Sand Fly Oviposition: Factors Affecting Skip Oviposition in Phlebotomus papatasi Sand Flies

2021 ◽  
Vol 21 (4) ◽  
pp. 280-288
Author(s):  
Lexua G. McLaughlin ◽  
Gideon Wasserberg
Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 162 ◽  
Author(s):  
Austin Merchant ◽  
Tian Yu ◽  
Jizhe Shi ◽  
Xuguo Zhou

Phlebotomus papatasi, an Old World sand fly species, is primarily responsible for the transmission of leishmaniasis, a highly infectious and potentially lethal disease. International travel, especially military rotations, between domestic locations and P. papatasi-prevalent regions in the Middle East poses an imminent threat to the public health of US citizens. Because of its small size and cryptic morphology, identification of P. papatasi is challenging and labor-intensive. Here, we developed a ribosomal DNA-polymerase chain reaction (PCR)-based diagnostic assay that is capable of detecting P. papatasi genomic DNA from mixed samples containing multiple sand flies native to the Americas. Serial dilution of P. papatasi samples demonstrated that this diagnostic assay could detect one P. papatasi from up to 255 non-target sand flies. Due to its simplicity, sensitivity and specificity, this rapid identification tool is suited for a long-term surveillance program to screen for the presence of P. papatasi in the continental United States and to reveal geographical regions potentially vulnerable to sand fly-borne diseases.


mBio ◽  
2019 ◽  
Vol 10 (4) ◽  
Author(s):  
Isabelle Louradour ◽  
Kashinath Ghosh ◽  
Ehud Inbar ◽  
David L. Sacks

ABSTRACT Sand flies are the natural vectors for the Leishmania species that produce a spectrum of diseases in their mammalian hosts, including humans. Studies of sand fly/Leishmania interactions have been limited by the absence of genome editing techniques applicable to these insects. In this report, we adapted CRISPR (clustered regularly interspaced palindromic repeat)/Cas9 (CRISPR-associated protein 9) technology to the Phlebotomus papatasi sand fly, a natural vector for Leishmania major, targeting the sand fly immune deficiency (IMD) pathway in order to decipher its contribution to vector competence. We established a protocol for transformation in P. papatasi and were able to generate transmissible null mutant alleles for Relish (Rel), the only transcription factor of the IMD pathway. While the maintenance of a homozygous mutant stock was severely compromised, we were able to establish in an early generation their greater susceptibility to infection with L. major. Flies carrying different heterozygous mutant alleles variably displayed a more permissive phenotype, presenting higher loads of parasites or greater numbers of infective-stage promastigotes. Together, our data show (i) the successful adaptation of the CRISPR/Cas9 technology to sand flies and (ii) the impact of the sand fly immune response on vector competence for Leishmania parasites. IMPORTANCE Sand flies are the natural vectors of Leishmania parasites. Studies of sand fly/Leishmania interactions have been limited by the lack of successful genomic manipulation of these insects. This paper shows the first example of successful targeted mutagenesis in sand flies via adaptation of the CRISPR/Cas9 editing technique. We generated transmissible null mutant alleles of relish, a gene known to be essential for the control of immune response in other insects. In addition to the expected higher level of susceptibility to bacteria, the mutant flies presented higher loads of parasites when infected with L. major, showing that the sand fly immune response impacts its vector competence for this pathogen.


2020 ◽  
Vol 17 (3) ◽  
pp. 0754
Author(s):  
Sahar Abd Abd ◽  
Riyadh Okail ◽  
Soolaf A. Kathiar ◽  
Nawras Mzahem

            The variation in wing morphological features was investigated using geometric morphometric technique of the Sand Fly from two Iraqi provinces Babylon and Diyala . We distributed eleven landmarks on the wings of Sand Fly species. By using the centroid size and shape together, all species were clearly distinguished.  It is clear from these results that the wing analysis is an essential method for future geometric morphometry studies to distinguish the species of Sand Flies in Iraq.


2021 ◽  
Author(s):  
Tatiana Sulesco ◽  

Phlebotomine sand flies are vectors of several infectious pathogens, including parasitic protozoans of the genus Leishmania and phleboviruses. Increasing sand fly biting nuisance reported by residents from southern Republic of Moldova since 2011 initiated this study. Ceadir-Lunga, a semi-urban locality in southern Republic of Moldova was selected for seasonal sand fly collections outdoors and indoors in 2015 and 2017 using CDC light traps and manual aspirators. Continuous trapping showed markedly longer activity of P. papatasi indoors. Specimens were collected from first aspirations in the second half of June until last collections in mid-September, suggesting that the actual indoor activity of P. papatasi may have been longer. Low numbers of trapped specimens do not allow make accurate conclusions regarding the seasonal dynamics.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Fatima Zahra Talbi ◽  
Chafika Faraj ◽  
Fouad EL-Akhal ◽  
Fatiha El Khayyat ◽  
Driss Chenfour ◽  
...  

Cutaneous leishmaniasis (CL) is an infectious disease caused by various species ofLeishmaniaand transmitted by several species of sand flies (Diptera: Psychodidae). In order to evaluate the risk of leishmaniasis transmission in Fes-Boulemane, an investigation was carried out in two localities, Aichoun and Bouasseme, during 2011. From January to December, 1120 specimens were collected in Aichoun comprising six species belonging to two genera:Phlebotomus sergenti(76.07%),Phlebotomus longicuspis(9.01%),Phlebotomus perniciosus(8.48%),Phlebotomus papatasi(4.82%),Sergentomyia minuta,andSergentomyia fallax. For Bouasseme, seven species were identified withPhlebotomus sergenti(60.39%) dominating, followed byPhlebotomus perniciosus(20%) andPhlebotomus longicuspis(12.15%). The remaining species,Phlebotomus papatasi,Phlebotomus ariasi,Sergentomyia minuta,andSergentomyia fallax,were less prevalent. The activity of sand flies in both localities is marked by the dominance ofPh. sergentiwith two peaks occurring in June and September. In order to obtain a better understanding of sand fly diversity among their species, results were analyzed by the ecological indices determinant: specific richness, the relative abundance, and Shannon-Weiner index (H′). Further studies of sand fly diversity should employ statistical tests and molecular analyses. This study can be useful in the implementation of appropriate future control measures.


Author(s):  
Mahboubeh Fatemi ◽  
Zahra Saeidi ◽  
Parviz Noruzian ◽  
Amir Ahmad Akhavan

Background: Due to strict ethical rules, the risk of accidental disease transmission and the most importantly, inconven­ience regarding using of live animals, artificial feeding apparatus has been developed for colonization of haematophagous insects. Rearing of sandfly is more difficult than other haematophagous insects. Methods: In the current study, a new apparatus for membrane feeding of Phlebotomus papatasi was designed, made and compared with available apparatus in Sand Fly Insectary, Tehran University of Medical Sciences, Tehran, Iran, in 2014. Results: In comparison to other apparatus designed for artificial feeding of other arthropods, our designed apparatus had the highest performance which after up to 1h, the majority of sand flies landed and took blood and among tested membranes, chicken skin was proved the most efficient membrane. Conclusion: Sand fly artificial feeding apparatus can be used at least for rearing of Ph. papatasi.


Author(s):  
Lindsey R Faw ◽  
Kasie Raymann ◽  
Nayma Romo Bechara ◽  
Gideon Wasserberg

Abstract Sand fly larvae develop in sheltered humid habitats containing decaying organic matter on which they feed. Previously, we showed that gravid females of Phlebotomus papatasi Scopoli (Diptera: Psychodidae) are attracted to and stimulated to lay eggs on larval rearing medium containing larvae. That study, however, did not control for the possible effect of medium aging. Our goal in this study was to evaluate the effect of larval substrate conditioning on attraction and oviposition responses of Ph. papatasi sand flies while controlling for the effect of substrate aging. Initially, we confirmed that the pretreatment fresh larval food sources (to be used as larval conditioned and unconditioned media) did not differ with respect to their effect on attraction and oviposition responses. The larval conditioned medium was produced by rearing larvae to the second/third-instar stage over 3 wk using the same larval food source. To produce larval unconditioned medium, the same amount of fresh larval food was added to a control rearing cup that did not contain larvae but was aged under identical time and conditions. Two-choice bioassays were conducted to evaluate gravid female’s attraction and oviposition response to larval conditioned and unconditioned media. We found that gravid females were significantly attracted (P < 0.05) to larval conditioned medium when compared with unconditioned medium under the same amount of time and conditions. However, no such difference was found with respect to oviposition response. Both attraction and oviposition responses were significantly increased for larval conditioned and unconditioned media in comparison to the initial fresh larval food source.


Author(s):  
Madhavi L Kakumanu ◽  
Bahjat F Marayati ◽  
Coby Schal ◽  
Charles S Apperson ◽  
Gideon Wasserberg ◽  
...  

Abstract Phlebotomine sand flies are worldwide vectors of Leishmania parasites as well as other bacterial and viral pathogens. Due to the variable impact of traditional vector control practices, a more ecologically based approach is needed. The goal of this study was to isolate bacteria from the most attractive substrate to gravid Phlebotomus papatasi Scopoli sand flies and determine the role of bacterial volatiles in the oviposition attractancy of P. papatasi using behavioral assays. We hypothesized that gravid sand flies are attracted to bacterially derived semiochemical cues associated with breeding sites. Bacteria were isolated from a larvae-conditioned rearing medium, previously shown to be highly attractive to sand flies. The isolated bacteria were identified by amplifying and sequencing 16S rDNA gene fragments, and 12 distinct bacterial species were selected for two-choice olfactometer bioassays. The mix of 12 bacterial isolates elicited strong attraction at the lower concentration of 107 cells per ml and significant repellence at a high concentration of 109 cells per ml. Three individual isolates (SSI-2, SSI-9, and SSI-11) were particularly attractive at low doses. In general, we observed dose-related effects, with some bacterial isolates stimulating negative and some positive dose–response curves in sand fly attraction. Our study confirms the important role of saprophytic bacteria, gut bacteria, or both, in guiding the oviposition-site selection behavior of sand flies. Identifying the specific attractive semiochemical cues that they produce could lead to development of an attractive lure for surveillance and control of sand flies.


2020 ◽  
Author(s):  
Megan A. Sloan ◽  
Jovana Sadlova ◽  
Tereza Lestinova ◽  
Mandy J. Sanders ◽  
James A. Cotton ◽  
...  

Abstract Background Leishmaniasis, caused by parasites of the genus Leishmania, is a disease that effects up to 8 million people worldwide. Parasites are transmitted to human and animal hosts through the bite of an infected sand fly. Novel strategies for disease control, require a better understanding of the key step for transmission namely, the establishment of infection inside the fly. Methods In this work we wanted to identify fly systemic transcriptomic signatures associated with Leishmania infection. We used next generation sequencing to describe the transcriptome of whole Phlebotomus papatasi sand flies when fed with blood alone (control) or with blood containing one of three trypanosomatids: Leishmania major, Leishmania donovani and Herpetomonas muscarum: a parasite not transmitted to humans. Results Of these, only L. major is able to successfully establish an infection in P. papatasi. However, the transcriptional signatures observed after each parasite-contaminated blood meal were not specific to success or failure of a specific infection and were not different from each other. They were also indistinguishable from non-contaminated blood. Conclusions This implies that sand flies perceive Leishmania as just one feature of their microbiome landscape and that any strategy to tackle transmission should focus on the response towards the blood meal rather than parasite establishment. Alternatively, Leishmania could suppress host responses. These results will generate new thinking around the concept of stopping transmission by controlling the parasite inside the insect.


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