Rapid screening for SARS-CoV-2 variants of concern in clinical and environmental samples using nested RT-PCR assays targeting key mutations of the spike protein.

New SARS-CoV-2 mutations are constantly emerging, raising concerns of increased transmissibility, virulence or escape from host immune response. We describe a nested RT-PCR assay (~1500 bps) to detect multiple nucleotide changes resulting in key spike protein mutations distinctive of the major known circulating SARS-CoV-2 variants, including the three Variants of Concern (VOCs) 20I/501Y.V1 (United Kingdom), 20H/501Y.V2 (South Africa), and 20 J/501Y.V3 (Brazil), as well as the 20E.EU1 variant (Spain), the CAL.20C recently identified in California, and the mink-associated variant (GR, lineage B.1.1.298). Prior to application to field samples, the discriminatory potential of this PCR assay was explored using GISAID and Nextclade. To extend variant detection to challenging matrices such as sewage, where the amplification of long fragments is problematic, two short nested RT-PCR assays (~300 bps) were also designed, targeting portions of the region spanned by the long nested assay. The three newly-designed assays were then tested on field samples, including 31 clinical samples (7 fully-sequenced swab samples, and 24 uncharacterized ones) and 34 urban wastewater samples, some of which collected in areas where circulation of VOCs had been reported. The long assay successfully amplified 29 of the 31 swabs (93%), allowing the correct identification of variants 20I/501Y.V1 and 20E.EU1 present in the panel of previously characterized samples. The Spanish variant was detected in 14/24 of the uncharacterized samples as well. The sequences obtained using the short assays were consistent with those obtained with the long assay. Mutations characteristic of VOCs (UK and Brazilian variant) and of other variant (Spanish) were detected in sewage samples. To our knowledge, this is the first evidence of the presence of sequences harboring key mutations of 20I/501Y.V1 and 20 J/501Y.V3 in urban wastewaters, highlighting the potential contribution of wastewater surveillance to explore SARS-CoV-2 diversity. The developed nested RT-PCR assays can be used as an initial rapid screening test to select clinical samples containing mutations of interest. This can speed up diagnosis and optimize resources since it allows full genome sequencing to be done only on clinically relevant specimens. The assays can be also employed for a rapid and cost-effective detection of VOCs or other variants in sewage for the purposes of wastewater-based epidemiology. The approach proposed here can be used to better understand SARS-CoV-2 variant diversity, geographic distribution and impact worldwide.

First-line carboplatin/nab-paclitaxel in advanced ovarian cancer patients, after hypersensitivity reaction to solvent-based taxanes: a single-institution experience.

One of the major challenges related to solvent-based taxanes administration in clinical practice is the high rate of hypersensitivity reactions (HSRs). Nab-paclitaxel is a solvent-free, albumin-bound, paclitaxel, which minimize the risk of HSR occurrence. In this single-institution, retrospective analysis, we evaluated stage IIIc-IV epithelial ovarian cancer (EOC) patients, treated with first-line carboplatin/nab-paclitaxel (± bevacizumab), after the occurrence of an HSR with solvent-based paclitaxel (and/or docetaxel). Between April 2012 and December 2018, ten patients (20.8%) received carboplatin/nab-paclitaxel (± bevacizumab) after the occurrence of an HSR to solvent-based taxanes. Among the evaluable patients, ORR was 100%. At median follow-up of 28.5 months, median PFS was 16.7 months, and median OS was 65.4 months, respectively. Median received dose intensity (DI) was 86% and 80% of the projected DI for nab-paclitaxel and carboplatin, respectively. There were no treatment-related grade 4 adverse events. Most relevant treatment-related grade 3 adverse events were: asthenia (10%), hypertransaminasemia (10%), neutropenia (20%), thrombocytopenia (20%), and anemia (10%). No HSR recurrence was observed. The high rate of HSR occurrence could limit first-line treatment options in clinical practice. Carboplatin/nab-paclitaxel association could represent a valid treatment option in this setting.

Avaliação da atividade antibacteriana da microalga Spirulina platensis / Assessment of the antibacterial activity of microalgae Spirulina platensis

Infecções são agravadas pelo aumento da resistência dos microrganismos a substâncias antimicrobianas. A necessidade de descoberta de novos medicamentos em decorrência desta resistência microbiana tem impulsionado o desenvolvimento de novas pesquisas. A Spirulina platensis, reconhecida pelas suas propriedades nutricionais, possui alta quantidade de compostos fenólicos, os quais podem apresentar também propriedades antimicrobianas. Objetivou-se cultivar a microalga Spirulina platensis, avaliar a produção de compostos fenólicos pela mesma, caracterizar a possível atividade antimicrobiana dos fenóis frente a Escherichia coli ATCC 25922, a Pseudomas aeruginosa ATCC 27853 e o Staphylococcus aureus ATCC 6538P e determinar a concentração inibitória mínima do extrato fenólico frente às bactérias citadas. Os resultados demonstraram que elevadas concentrações de nitrato de sódio (4g/L) no meio de cultivo não aumentaram a produção de compostos fenólicos. A microalga cultivada com 2 g/L de nitrato de sódio apresentou 2,13 mg/g de compostos fenólicos, sendo que os extratos apresentaram atividade antibacteriana contra o S. aureus, bactéria Grampositiva, com halo de inibição de 22 mm e 19 mm e concentração inibitória mínima de 47,46 mg/mL, indicando sua importância como potencial inibidor de S. aureus.

Bacterial infections are aggravated by the increasing resistance of microorganisms to antimicrobial substances. The need to discover new medicines to evade microbial resistance is the driving force behind much new research. The microalga Spirulina platensis, recognized for its nutritional properties, has a high content of phenolic compounds, which can provide antimicrobial properties. The objective of this study was to establish a culture of Spirulina platensis, estimate the production of phenolic compounds by this microalga, characterize the antimicrobial activity of the phenolics against microorganisms such as Escherichia coli ATCC 25922, Pseudomas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 6538P and determine the minimum inhibitory concentration (MIC) of the phenolic extract for these bacteria. It was found that adding high concentrations of sodium nitrate (4 g/L) to the medium did not increase the production of phenolic compounds. The microalgae grown with 2 g/L sodium nitrate produced 2.13 mg/g of phenolic compounds, and the extracts showed antibacterial activity against S. aureus, a Gram-positive bacterium, with inhibition haloes of 22 mm and 19 mm and a MIC of 47.46 mg/ mL, indicating its importance as a potential S. aureus inhibitor.

A multicenter, randomized, phase III study of docetaxel plus best supportive care versus best supportive care in chemotherapy-naive patients with metastatic or non-resectable localized non-small cell lung cancer (NSCLC).

This was an open-label randomized Phase III study of 207 patients with either unresectable or metastatic non-small cell lung cancer (NSCLC) who were treated with docetaxel plus best supportive care (BSC) or best supportive care alone. Patients in the chemotherapy arm of the study received docetaxel 100 mg/m(2) as a 1 h intravenous infusion every 21 days until they showed evidence of progressive disease, or estimated maximum benefit obtained or unacceptable side effects. Patients who received docetaxel were pretreated with oral dexamethasone. Patients in the BSC arm should not receive chemotherapy or anticancer therapy except for palliative radiotherapy. Overall survival obtained in the docetaxel arm was significantly longer than in the BSC arm (P=0.026). Two-year survival in the docetaxel arm was 12%, whereas none of the BSC patients survived after 20 months. The response rate was 13.1% (95% CI, 7.5-18.8%). There was a significantly longer time to progression in the docetaxel versus the BSC arm (P<0.001), and statistically significant improvement of clinical symptoms with docetaxel compared to BSC. The quality-of-life descriptors were in favor of docetaxel, and the difference was significant for pain, dyspnea and emotional functioning. The safety profile of docetaxel for this study was similar to that already reported in this patient population.

Isoenzyme analysis of Entamoeba histolytica for evaluation of pathogenicity: detection of zymodeme XIX in South America.

Authors report the results of the isoenzyme analysis of strains of Entamoeba histolytica isolated from international travellers. This recently developed method allows the detection of pathogenic strains by evaluating the electrophoretic mobility of cytoplasmic enzymes and was proved to be more reliable and quickly feasible than previous ones. The experience reported refers to three strains isolated from travellers coming from Ecuador, Brazil and Indonesia, respectively; the zymodeme XIX (in accordance with the Sargeaunt's classification) was identified in all the three cases. This zymodeme has been first detected in 1981 and should currently be considered rare; moreover, it has never been previously reported from the Americas.