Filarial nematode phenotypic screening cascade to identify compounds with anti-parasitic activity for drug discovery optimization.

Filarial diseases, including lymphatic filariasis and onchocerciasis, are considered among the most devastating of all tropical diseases, affecting over 86 million people worldwide. To control and more rapidly eliminate onchocerciasis requires treatments that target the adult stage of the parasite. Drug discovery efforts are challenged by the lack of preclinical animal models using the human-pathogenic filariae, requiring the use of surrogate parasites for Onchocerca volvulus for both ex vivo and in vivo evaluation. Herein, we describe a platform utilizing phenotypic ex vivo assays consisting of the free-living nematode Caenorhabditis elegans, microfilariae and adult filariae of the bovine filariae Onchocerca lienalis and Onchocerca gutturosa, respectively, as well as microfilariae and adult filariae of the feline filariae Brugia pahangi, the rodent filariae Litomosoides sigmodontis and the human-pathogenic filariae Brugia malayi to assess activity across various surrogate parasites. Utilization of those surrogate nematodes for phenotypic ex vivo assays in order to assess activity across various parasites led to the successful establishment of a screening cascade and identification of multiple compounds with potential macrofilaricidal activity and desirable physicochemical, MW = 200-400 and low lipophilicity, logP <4, and pharmacokinetic properties, rat and human liver S9 stability of ≥70% remaining at 60 min, and AUC exposures above 3 µM h. This platform demonstrated the successful establishment of a screening cascade which resulted in the discovery of potential novel macrofilaricidal compounds for futher drug discovery lead optimization efforts. This screening cascade identified two distinct chemical series wherein one compound produced a significant 68% reduction of adult Litomosoides sigmodontis in the mouse model. Successful demonstration of efficacy prompted lead optimization medicinal chemistry efforts for this novel series.

Development and Implementation of a Simple and Rapid Extraction-Free Saliva SARS-CoV-2 RT-LAMP Workflow for Workplace Surveillance

Effective management of the COVID-19 pandemic requires widespread and frequent testing of the population for SARS-CoV-2 infection. Saliva has emerged as an attractive alternative to nasopharyngeal samples for surveillance testing as it does not require specialized personnel or materials for its collection and can be easily provided by the patient. We have developed a simple, fast, and sensitive saliva-based testing workflow that requires minimal sample treatment and equipment. After sample inactivation, RNA is quickly released and stabilized in an optimized buffer, followed by reverse transcription loop-mediated isothermal amplification (RT-LAMP) and detection of positive samples using a colorimetric and/or fluorescent readout. The workflow was optimized using 1,670 negative samples collected from 172 different individuals over the course of 6 months. Each sample was spiked with 50 copies/L of inactivated SARS-CoV-2 virus to monitor the efficiency of viral detection. Using pre-defined clinical samples, the test was determined to be 100% specific and 97% sensitive, with a limit of detection comparable to commercially available RT-qPCR-based diagnostics. The method was successfully implemented in a CLIA laboratory setting for workplace surveillance and reporting. From April 2021-February 2022, more than 30,000 self-collected samples from 755 individuals were tested and 85 employees tested positive mainly during December and January, consistent with high infections rates in Massachusetts and nationwide. The rapid identification and isolation of infected individuals with trace viral loads before symptom onset minimized viral spread in the workplace.

Platelet antibody screening and crossmatch in Chengdu in 2019 / 中国输血杂志

【Objective】 To analyze the status of the platelet antibody screening and crossmatch in Chengdu in 2019, so as to further improve the corresponding detection strategy to improve the clinical transfusion efficacy. 【Methods】 The patients underwent platelet antibody crossmatch in Chengdu Blood Center in 2019 were selected as research objects Platelet antibody screening and crossmatch were performed by solid-phase agglutination technique, and the sample size, the incidence of platelet antibod, age, blood group, seasonal chracteristics, hospital levels, ratio of repeated crossmatch and the transfusion efficacy were analyzed. 【Results】 321 treatment doses of matched platelets after 259 occasions of crossmatch relative to 85 patients were provided. The positive rate of platelet antibody was 87.06%. 64.71% of the patients were over 40 years old, the proportion of ABO group in crossmatch samples was O>A>B>AB, and the crossmatch cases increased each quarter gradually. All samples were provided by tertiary hospitals. 52.94% of the patients needed crossmatch at least twice, and the efficacy rate of matched platelets transfusion was 63.64%. 【Conclusion】 The platelet transfusion efficacy could by improved by platelet antibody screening and crossmatch, so as to avoid the waste of platelets, which deserves active promotion in clinical.

EFFECT OF PHOSPHATE ON COLICIN V FORMATION BY STRAINS OF ESCHERICHIA COLI / 微生物学通报

ColV~+ strains of Escherichia coli produced larger inhibitory zones when these strains grown on nutrient agar containing phosphate after overlaid sensitive indicators. This appears that production of colicin V is increased by the addition of phosphate to nutrient agar. It was sure that stimulation of phosphate to colicin V formation results from its effect in reducing divalent cation levels in nutrient agar since adding EDTA to nutrient agar had the same effect as phosphate, but the addition of Mg~(2+) or Ca~(2+) had the oppsite effect. Therefore nutrient agar supplemented with phosphate can be used to isolate and identificate ColV~+ strains of E. coli.