scholarly journals Serological Evidence of Phleboviruses in Domestic Animals on the Pre-Apennine Hills (Northern Italy)

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1577
Author(s):  
Davide Lelli ◽  
Vittorio Scanferla ◽  
Ana Moreno ◽  
Enrica Sozzi ◽  
Valentina Ravaioli ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Domestic Animals ◽  
Preliminary Evidence ◽  
Neutralization Assay ◽  
Northern Italy ◽  
Sand Fly ◽  
Sand Flies ◽  
Toscana Virus ◽  
Virus Neutralization Assay

Phleboviruses are arboviruses transmitted by sand flies, mosquitoes and ticks. Some sand fly-borne phleboviruses cause illnesses in humans, such as the summer fevers caused by the Sicilian and Naples viruses or meningitis caused by the Toscana virus. Indeed, traces of several phleboviral infections have been serologically detected in domestic animals, but their potential pathogenic role in vertebrates other than humans is still unclear, as is the role of vertebrates as potential reservoirs of these viruses. In this study, we report the results of a serological survey performed on domestic animals sampled in Northern Italy, against four phleboviruses isolated from sand flies in the same area. The sera of 23 dogs, 165 sheep and 23 goats were tested with a virus neutralization assay for Toscana virus, Fermo virus, Ponticelli I virus and Ponticelli III virus. Neutralizing antibodies against one or more phleboviruses were detected in four out of 23 dogs, 31 out of 165 sheep and 12 out of 23 goats. This study shows preliminary evidence for the distribution pattern of phleboviral infections in different animal species, highlighting the potential infection of the Toscana virus in dogs and the Fermo virus in goats.

Molecular and biochemical characterization of a sand fly population from Sri Lanka: evidence for insecticide resistance due to altered esterases and insensitive acetylcholinesterase

2005 ◽  
Vol 95 (4) ◽  
pp. 371-380 ◽  
Author(s):  
S.N. Surendran ◽  
S.H.P.P. Karunaratne ◽  
Z. Adamsn ◽  
J. Hemingway ◽  
N.J. Hawkes
Keyword(s):  
Sri Lanka ◽  
Insecticide Resistance ◽  
Biochemical Characterization ◽  
Preliminary Evidence ◽  
Resistance Mechanisms ◽  
Sand Fly ◽  
Cross Resistance ◽  
Cytochrome P450 Monooxygenases ◽  
Sand Flies

AbstractWith an increasing incidence of cutaneous leishmaniasis in Sri Lanka, particularly in northern provinces, insecticide-mediated vector control is under consideration. Optimizing such a strategy requires the characterization of sand fly populations in target areas with regard to species composition and extant resistance, among other parameters. Sand flies were collected by human bait and cattle-baited net traps on Delft Island, used as an illegal transit location by many refugees returning to the north of Sri Lanka from southern India where leishmaniasis is endemic. For species identification, genomic DNA was extracted and a fragment of the ribosomal 18S gene amplified. The sequence from all flies analysed matched that of Phlebotomus argentipes Annandale & Brunetti, the primary vector in India and the most likely vector in Sri Lanka. Independent morphological analysis also identified P. argentipes. To establish the current susceptibility status of vector species, data were obtained at the biochemical level, from which potential cross-resistance to alternative insecticides can be predicted. The Delft Island collection was assayed for the activities of four enzyme systems involved in insecticide resistance (acetylcholinesterase, non-specific carboxylesterases, glutathione-S-transferases and cytochrome p450 monooxygenases), establishing baselines against which subsequent collections can be evaluated. There was preliminary evidence for elevated esterases and altered acetylcholinesterase in this population, the first report of these resistance mechanisms in sand flies to our knowledge, which probably arose from the malathion-based spraying regimes of the Anti-Malarial Campaign.

scholarly journals Isolation of a Trypanosome Related to Trypanosoma theileri (Kinetoplastea: Trypanosomatidae) from Phlebotomus perfiliewi (Diptera: Psychodidae)

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Mattia Calzolari ◽  
Gianluca Rugna ◽  
Emanuela Clementi ◽  
Elena Carra ◽  
Marco Pinna ◽  
...  
Keyword(s):  
Taxonomic Status ◽  
Morphological Characters ◽  
Sand Fly ◽  
Sand Flies ◽  
Transmission Cycle ◽  
Phlebotomus Perfiliewi ◽  
Insect Group ◽  
Very High ◽  
Trypanosoma Theileri

The Trypanosoma theileri group includes several trypanosome species hardly distinguishable due to the lack of discriminating morphological characters. Trypanosomes belonging to this group have been isolated from different bovine, ovine, and cervids in Europe, Africa, Asia, and Americas. The principal vectors of the T. theileri group are considered tabanid flies; however, T. melophagium is transmitted exclusively by sheep keds. In 2016, 128 sand flies out of 2,728 trapped in Valsamoggia municipality, Italy, were individually dissected and an unknown trypanosome strain, named TrPhp1, was isolated from a female of the sand fly Phlebotomus perfiliewi. Sequence analysis placed this trypanosome in the T. theileri group with very high homology to other trypanosomes detected in European cervids. This is the first report of the T. theileri group isolation from a sand fly, and the possible role of this insect group in the trypanosome transmission cycle is discussed. Within the T. theileri group, the phylogenetic analysis distinguished several lineages, which, unfortunately, do not correspond with their host specificity and their taxonomic status remains ambiguous.

scholarly journals Inference of SARS-CoV-2 spike-binding neutralizing antibody titers in sera from hospitalized COVID-19 patients by using commercial enzyme and chemiluminescent immunoassays

2020 ◽  
Author(s):  
Arantxa Valdivia ◽  
Ignacio Torres ◽  
Victor Latorre ◽  
Carla Frances-Gomez ◽  
Eliseo Albert ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Virus Neutralization ◽  
Pseudotyped Virus ◽  
S Protein ◽  
Neutralizing Activity ◽  
Virus Neutralization Assay ◽  
Degree Correlation ◽  
Antibody Titers

Background: Whether antibody levels measured by commercially-available enzyme or chemiluminescent immunoassays targeting the SARS-CoV-2 spike (S) protein can act as a proxy for serum neutralizing activity remains to be established for many of these assays. Objectives: To evaluate the degree of correlation between neutralizing antibodies (NtAb) binding the SARS-CoV-2 Spike (S) protein and SARS-CoV-2-S-IgG levels measured by four commercial immunoassays in sera drawn from hospitalized COVID-19 patients. Patients and Methods: Ninety sera from 51 hospitalized COVID-19 patients were assayed by a pseudotyped virus neutralization assay, the LIAISON SARS-CoV-2 S1/S2 IgG, the Euroimmun SARS-CoV-2 IgG ELISA, the MAGLUMI 2019-nCoV IgG and the COVID-19 ELISA IgG assays. Results: Overall, the results obtained with the COVID-19 ELISA IgG test showed the highest agreement with the NtAb assay (κ, 0.85; 95% CI, 0.63-1). The most sensitive tests were the pseudotyped virus NtAb assay and the COVID-19 ELISA IgG assay (92.2% for both). Overall, the degree correlation between antibody titers resulting in 50% virus neutralization (NtAb50) in the pseudotyped virus assay and SARS-CoV-2 IgG levels was strong for the Euroimmun SARS-CoV-2 IgG ELISA (Rho=0.73) and moderate for the remaining assays (Rho=0.48 to 0.59). The kinetic profile of serum NtAb50 titers could not be reliably predicted by any of the SARS-CoV-2 IgG immunoassays. Conclusions: the suitability of SARS-CoV-2-S-IgG commercial immunoassays for inferring neutralizing activity of sera from hospitalized COVID-19 patients varies widely across tests and is influenced by the time of sera collection after the onset of symptoms.

scholarly journals Development of a Sensitive Detection Method for Alphaviruses and Its Use as a Virus Neutralization Assay

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1191
Author(s):  
Christin Schmidt ◽  
Mario Perkovic ◽  
Barbara S. Schnierle
Keyword(s):  
Neutralizing Antibodies ◽  
High Sensitivity ◽  
Neutralization Assay ◽  
Open Reading Frames ◽  
Virus Neutralization ◽  
Structural Genes ◽  
Virus Neutralization Assay ◽  
Subgenomic Promoter ◽  
Mayaro Virus ◽  
Reading Frames

Alphaviruses have a single-stranded, positive-sense RNA genome that contains two open reading frames encoding either the non-structural or the structural genes. Upon infection, the genomic RNA is translated into the non-structural proteins (nsPs). NsPs are required for viral RNA replication and transcription driven from the subgenomic promoter (sgP). Transfection of an RNA encoding the luciferase gene under the control of the sgP into cells enabled the detection of replication-competent chikungunya virus (CHIKV) or Mayaro virus (MAYV) with high sensitivity as a function of the induced luciferase activity. This assay principle was additionally used to analyze virus-neutralizing antibodies in sera and might be an alternative to standard virus neutralization assays based on virus titration or the use of genetically modified tagged viruses.

scholarly journals Broader Geographical Distribution of Toscana Virus in the Mediterranean Region Suggests the Existence of Larger Varieties of Sand Fly Vectors

2020 ◽  
Vol 8 (1) ◽  
pp. 114 ◽  
Author(s):  
Nazli Ayhan ◽  
Jorian Prudhomme ◽  
Lison Laroche ◽  
Anne-Laure Bañuls ◽  
Remi N. Charrel
Keyword(s):  
Current Knowledge ◽  
Case Reports ◽  
Febrile Illness ◽  
Sand Fly ◽  
Sand Flies ◽  
Toscana Virus ◽  
Natural Conditions ◽  
Future Studies ◽  
The Mediterranean ◽  
Sand Fly Vectors

Toscana virus (TOSV) is endemic in the Mediterranean basin, where it is transmitted by sand flies. TOSV can infect humans and cause febrile illness as well as neuroinvasive infections affecting the central and peripheral nervous systems. Although TOSV is a significant human pathogen, it remains neglected and there are consequently many gaps of knowledge. Recent seroepidemiology studies and case reports showed that TOSV’s geographic distribution is much wider than was assumed a decade ago. The apparent extension of the TOSV circulation area raises the question of the sandfly species that are able to transmit the virus in natural conditions. Phlebotomus (Ph.) perniciosus and Ph. perfiliewi were historically identified as competent species. Recent results suggest that other species of sand flies could be competent for TOSV maintenance and transmission. Here we organize current knowledge in entomology, epidemiology, and virology supporting the possible existence of additional phlebotomine species such as Ph. longicuspis, Ph. sergenti, Ph. tobbi, Ph. neglectus, and Sergentomyia minuta in TOSV maintenance. We also highlight some of the knowledge gaps to be addressed in future studies.

scholarly journals The role of dermis resident macrophages and their interaction with neutrophils in the early establishment of Leishmania major infection transmitted by sand fly bite

2020 ◽  
Author(s):  
Mariana M. Chaves ◽  
Sang Hun Lee ◽  
Olena Kamenyeva ◽  
Kashinath Ghosh ◽  
David Sacks
Keyword(s):  
Flow Cytometry ◽  
Tyrosine Kinases ◽  
Leishmania Major ◽  
Receptor Tyrosine Kinases ◽  
Sand Fly ◽  
Sand Flies ◽  
Cellular Interactions ◽  
Anti Inflammatory ◽  
Severe Pathology

AbstractThere is substantial experimental evidence to indicate that Leishmania infections that are transmitted naturally by the bites of infected sand flies differ in fundamental ways from the inflammatory and immune reactions initiated by needle inocula. We have used flow cytometry and intravital microscopy (IVM) to reveal the heterogeneity of sand fly transmission sites with respect to the subsets of phagocytes in the skin that harbor L. major within the first hours and days after infection. By flow cytometry analysis, dermis resident macrophages (TRMs) were on average the predominant infected cell type at 1 hr and 24 hr. By confocal IVM, the co-localization of L. major and neutrophils varied depending on the proximity of deposited parasites to the presumed site of vascular damage, defined by the highly localized swarming of neutrophils. Some of the dermal TRMs could be visualized acquiring their infections via transfer from or efferocytosis of parasitized neutrophils, providing direct evidence for the “Trojan Horse” model. The role of neutrophil engulfment by dermal TRMs and the involvement of the Tyro3/Axl/Mertk family of receptor tyrosine kinases in these interactions and in sustaining the anti-inflammatory program of dermal TRMs was supported by the effects observed in neutrophil depleted and in Axl-/-Mertk-/- mice. The Axl-/-Mertk-/- mice also displayed reduced parasite burdens but more severe pathology following L. major infection transmitted by sand fly bite.SummarySand flies transmit Leishmania major which causes cutaneous leishmaniasis in humans and in non-human hosts. Our analyses of sand fly transmission sites of L. major in the mouse skin revealed that dermis resident macrophages (TRM) were the predominant phagocytes to take up the parasite within the first 24 hr post-bite. The early involvement of neutrophils varied depending on the proximity of deposited parasites to the site of tissue damage around which the neutrophils coalesced. By intra-vital microscopy, some of the dermal TRMs could be visualized acquiring their infections by direct transfer from or phagocytosis of parasitized neutrophils. The involvement of the Tyro3/Axl/Mertk family of receptor tyrosine kinases in these cellular interactions and in sustaining the anti-inflammatory functions of dermal TRMs was supported by the reduced parasite burdens but more severe pathology observed in Axl-/-Mertk-/- mice. The heterogeneity of sand fly transmission sites with respect to the dose of parasites and the early cellular interactions described here likely contribute to the wide range of infection outcomes that are associated with natural transmission of L. major observed in mouse models and possibly humans.

scholarly journals Quantifying absolute neutralization titers against SARS-CoV-2 by a standardized virus neutralization assay allows for cross-cohort comparisons of COVID-19 sera

2020 ◽  
Author(s):  
Kasopefoluwa Y. Oguntuyo ◽  
Christian S Stevens ◽  
Chuan-Tien Hung ◽  
Satoshi Ikegame ◽  
Joshua A. Acklin ◽  
...  
Keyword(s):  
Viral Entry ◽  
High Throughput Screening ◽  
Neutralizing Antibodies ◽  
Neutralization Assay ◽  
Virus Neutralization ◽  
Strong Positive Correlation ◽  
Plasma Therapy ◽  
Live Virus ◽  
Virus Neutralization Assay ◽  
Marked Variability

The global COVID-19 pandemic has mobilized efforts to develop vaccines and antibody-based therapeutics, including convalescent plasma therapy, that inhibit viral entry by inducing or transferring neutralizing antibodies (nAbs) against the SARS-CoV-2 spike glycoprotein (CoV2-S). However, rigorous efficacy testing requires extensive screening with live virus under onerous BSL3 conditions which limits high throughput screening of patient and vaccine sera. Myriad BSL-2 compatible surrogate virus neutralization assays (VNAs) have been developed to overcome this barrier. Yet, there is marked variability between VNAs and how their results are presented, making inter-group comparisons difficult. To address these limitations, we developed a standardized VNA using VSVdeltaG-based CoV-2-S pseudotyped particles (CoV2pp) that can be robustly produced at scale and generate accurate neutralizing titers within 18 hours post-infection. Our standardized CoV2pp VNA showed a strong positive correlation with CoV2-S ELISA and live virus neutralizations in confirmed convalescent patient sera. Three independent groups subsequently validated our standardized CoV2pp VNA (n>120). Our data show that absolute (abs) IC50, IC80, and IC90 values can be legitimately compared across diverse cohorts, highlight the substantial but consistent variability in neutralization potency across these cohorts, and support the use of absIC80 as a more meaningful metric for assessing the neutralization potency of vaccine or convalescent sera. Lastly, we used our CoV2pp in a screen to identify ultra-permissive 293T clones that stably express ACE2 or ACE2+TMPRSS2. When used in combination with our CoV2pp, we can now produce CoV2pp sufficient for 150,000 standardized VNA/week.

Sign in / Sign up

Export Citation Format

Share Document