Development and application of species ID and insecticide resistance assays, for monitoring sand fly Leishmania vectors in the Mediterranean basin and in the Middle East.

Background: Development of insecticide resistance (IR) in sand fly populations is an issue of public health concern, threatening leishmaniasis mitigation efforts by insecticide-based vector control. There is a major knowledge gap in the IR status of wild populations worldwide, possibly attributed to the unavailability of specialized tools, such as bioassay protocols, species baseline susceptibility to insecticides and molecular markers, to monitor such phenomena in sand flies.

Methodology/principal Findings: Sand fly populations from (semi-)rural regions of Greece, Turkey and Iran were sampled and identified to species, showing populations' structure in accordance with previously reported data.

Evaluation of a near-patient SARS-CoV-2 novel rapid diagnostic platform.

The goal of this study is to test a novel device and methodology based on the "Pebble" platform and real-time quantitative colorimetric loop-mediated isothermal amplification (qcLAMP) during SARS-CoV-2 detection using crude samples and extracted RNA. The new method employs an inexpensive lightweight device aimed toward rapid point-of-care testing. An extensive evaluation was performed consisting of 1,693 clinical samples across five independent clinical testing centers.

Comparative Genomics Uncovers the Evolutionary Dynamics of Detoxification and Insecticide Target Genes Across 11 Phlebotomine Sand Flies.

Sand flies infect more than 1 million people annually with Leishmania parasites and other bacterial and viral pathogens. Progress in understanding sand fly adaptations to xenobiotics has been hampered by the limited availability of genomic resources. To address this gap, we sequenced, assembled, and annotated the transcriptomes of 11 phlebotomine sand fly species.

Molecular monitoring of insecticide resistance in major disease vectors in Armenia.

Background: Armenia is considered particularly vulnerable to life-threatening vector-borne diseases (VBDs) including malaria, West Nile virus disease and leishmaniasis. However, information relevant for the control of the vectors of these diseases, such as their insecticide resistance profile, is scarce. The present study was conducted to provide the first evidence on insecticide resistance mechanisms circulating in major mosquito and sand fly populations in Armenia.

The Implementation of a Health Care Worker Screening Program Based on the Advanta RT-qPCR Saliva Assay in a Tertiary Care Referral Hospital in Northern Greece.

Health care workers are at increased risk of acquiring SARS-CoV-2 infection due to different exposures in the community and in hospital settings. Interventions implemented to avoid nosocomial outbreaks include preventive testing strategies. In this report, we present results from the mass screening program applied in our hospital to all professionals, irrespective of symptoms or risk of exposure.

A Practical Insecticide Resistance Monitoring Bioassay for Orally Ingested Dinotefuran in Anopheles Malaria Vectors.

Attractive Toxic Sugar Baits (ATSB) deployed outdoors are likely to be particularly effective against outdoor biting mosquitoes and, if they contain insecticides with a different mode of action, mosquitoes resistant to pyrethroids. One such ATSB based on the neonicotinoid dinotefuran is currently under evaluation in Africa. As with any insecticide-based intervention, it will be important to monitor for the possible emergence of vector resistance.

A Oxopurine Transporter Binds Nucleobases and Nucleosides Using Different Binding Modes.

is unable to synthesize purines de novo, instead salvages them from its environment, inside the host cell, for which they need high affinity carriers. Here, we report the expression of a Equilibrative Nucleoside Transporter, Tg244440, in a strain from which nucleobase transporters have been deleted. Tg244440 transported hypoxanthine and guanine with similar affinity ( ~1 µM), while inosine and guanosine displayed values of 4.

A Novel Real-Time RT-PCR-Based Methodology for the Preliminary Typing of SARS-CoV-2 Variants, Employing Non-Extendable LNA Oligonucleotides and Three Signature Mutations at the Spike Protein Receptor-Binding Domain.

Mutations resulting in amino-acid substitutions of the SARS-CoV-2 spike protein receptor-binding domain (RBD) have been associated with enhanced transmissibility and immune escape of the respective variants, namely Alpha, Beta, Gamma or Delta. Rapid identification of the aforementioned variants of concern and their discrimination of other variants is thus of importance for public health interventions. For this reason, a one-step real-time RT-PCR assay employing four locked nucleic acid (LNA) modified TaqMan probes was developed, to target signature mutations associated with amino-acid substitutions at positions 478, 484 and 501 present in the receptor-binding motif (RBM) of the spike protein RBD.

Evaluation of the Advanta Dx SARS-CoV-2 RT-PCR Assay, a High-Throughput Extraction-Free Diagnostic Test for the Detection of SARS-CoV-2 in Saliva: A Diagnostic Accuracy Study.

Nasopharyngeal swab specimen (NPS) molecular testing is considered the gold standard for SARS-CoV-2 detection. However, saliva is an attractive, noninvasive specimen alternative. The aim of the study was to evaluate the diagnostic accuracy of Advanta Dx SARS-CoV-2 RT-PCR saliva-based assay against paired NPS tested with either NeumoDx SARS-CoV-2 assay or Abbott Real Time SARS-CoV-2 assay as the reference method.

A one-step real-time RT-PCR assay for simultaneous typing of SARS-CoV-2 mutations associated with the E484K and N501Y spike protein amino-acid substitutions.

The emergence of SARS-CoV-2 mutations resulting in the S protein amino-acid substitutions N501Y and E484K, which have been associated with enhanced transmissibility and immune escape, respectively, necessitates immediate actions, for which their rapid identification is crucial. For the simultaneous typing of both of these mutations of concern (MOCs), a one-step real-time RT-PCR assay employing four locked nucleic acid (LNA) modified TaqMan probes was developed. The assay is highly sensitive with a LOD of 117 copies/reaction, amplification efficiencies >94 % and a linear range of over 5 log copies/reaction.

Bioassay and molecular monitoring of insecticide resistance status in Aedes albopictus populations from Greece, to support evidence-based vector control.

Background: Aedes albopictus has a well-established presence in southern European countries, associated with recent disease outbreaks (e.g. chikungunya).

NmeA, a novel efflux transporter specific for nucleobases and nucleosides, contributes to metal resistance in Aspergillus nidulans.

Through Minos transposon mutagenesis we obtained A. nidulans mutants resistant to 5-fluorouracil due to insertions into the upstream region of the uncharacterized gene nmeA, encoding a Major Facilitator Superfamily (MFS) transporter. Minos transpositions increased nmeA transcription, which is otherwise extremely low under all conditions tested.