The impact of yeast-encapsulated orange oil in Aedes aegypti oviposition.

The yeast-encapsulated orange oil (YEOO) is a novel larvicide under development against vector mosquitoes. Despite its efficiency against Aedes aegypti (L.) in small scale experiments, its applicability in vector control can be influenced by other effects on mosquito behaviour or physiology. For this reason, the impact of YEOO particles in mosquito oviposition was evaluated in laboratory and semi-field conditions. Oviposition assays with one gravid Aedes aegypti female were carried under laboratory and semi-field conditions with natural light and temperature fluctuation. For all ovitraps, the number of eggs was manually counted in the wooden paddle and in the solution of each ovitrap. The proportion of eggs between substrates (wooden paddle and solution) varied between conditions, with females in laboratory presenting a lower preference to lay eggs in paddles when compared with studies in semi-field. This behaviour shifts in laboratory can create challenges to extrapolate results from laboratory to the field. Here, studies in both conditions indicate a similar impact of YEOO particles in Aedes aegypti oviposition. The potential treatment concentration of YEOO particles presents a strong repellent/deterrent effect (-0.559 > OAI > -0.760) within the initial 72h of application when compared with water, and weak repellent/deterrent signal (OAI = -0.220) when compared against inactivated yeast. Control ovitraps with water were more positive for egg presence than treated ovitraps, while ovitraps with YEOO particles and inactivated yeast present similar number of positive ovitraps. It is possible that the repellent/deterrent action is partially driven by the delivery system, since most times Citrus sinensis EO oviposition repellent/deterrent signal is weak, and it seem influenced by solvent/delivery used. However, it is unclear how the yeast wall that protect/surrounds the orange oil will negatively affect oviposition since live yeast are normally consider an attractant for mosquito oviposition.

Isolation of nucleic acids using liquid-liquid phase separation of pH-sensitive elastin-like polypeptides.

Extraction of nucleic acids (NAs) is critical for many methods in molecular biology and bioanalytical chemistry. NA extraction has been extensively studied and optimized for a wide range of applications and its importance to society has significantly increased. The COVID-19 pandemic highlighted the importance of early and efficient NA testing, for which NA extraction is a critical analytical step prior to the detection by methods like polymerase chain reaction. This study explores simple, new approaches to extraction using engineered smart nanomaterials, namely NA-binding, intrinsically disordered proteins (IDPs), that undergo triggered liquid-liquid phase separation (LLPS). Two types of NA-binding IDPs are studied, both based on genetically engineered elastin-like polypeptides (ELPs), model IDPs that exhibit a lower critical solution temperature in water and can be designed to exhibit LLPS at desired temperatures in a variety of biological solutions. We show that ELP fusion proteins with natural NA-binding domains can be used to extract DNA and RNA from physiologically relevant solutions. We further show that LLPS of pH responsive ELPs that incorporate histidine in their sequences can be used for both binding, extraction and release of NAs from biological solutions, and can be used to detect SARS-CoV-2 RNA in samples from COVID-positive patients.

Disproportionate impact of COVID-19 severity and mortality on hospitalized American Indian/Alaska Native patients.

Epidemiological data across the United States of America illustrate health disparities in COVID-19 infection, hospitalization, and mortality by race/ethnicity. However, limited information is available from prospective observational studies in hospitalized patients, particularly for American Indian or Alaska Native (AI/AN) populations. Here, we present risk factors associated with severe COVID-19 and mortality in patients (4/2020-12/2021, n = 475) at the University of New Mexico Hospital. Data were collected on patient demographics, infection duration, laboratory measures, comorbidities, treatment(s), major clinical events, and in-hospital mortality. Severe disease was defined by COVID-related intensive care unit requirements and/or death. The cohort was stratified by self-reported race/ethnicity: AI/AN (30.7%), Hispanic (47.0%), non-Hispanic White (NHW, 18.5%), and Other (4.0%, not included in statistical comparisons). Despite similar timing of infection and comparable comorbidities, admission characteristics for AI/AN patients included younger age (P = 0.02), higher invasive mechanical ventilation requirements (P = 0.0001), and laboratory values indicative of more severe disease. Throughout hospitalization, the AI/AN group also experienced elevated invasive mechanical ventilation (P < 0.0001), shock (P = 0.01), encephalopathy (P = 0.02), and severe COVID-19 (P = 0.0002), consistent with longer hospitalization (P < 0.0001). Self-reported AI/AN race/ethnicity emerged as the highest risk factor for severe COVID-19 (OR = 3.19; 95% CI = 1.70-6.01; P = 0.0003) and was a predictor of in-hospital mortality (OR = 2.35; 95% CI = 1.12-4.92; P = 0.02). Results from this study highlight the disproportionate impact of COVID-19 on hospitalized AI/AN patients, who experienced more severe illness and associated mortality, compared to Hispanic and NHW patients, even when accounting for symptom onset and comorbid conditions. These findings underscore the need for interventions and resources to address health disparities in the COVID-19 pandemic.

Entire Expressed Peripheral Blood Transcriptome in Pediatric Severe Malarial Anemia.

This study on severe malarial anemia (SMA: Hb < 6.0 g/dL), a leading global cause of childhood morbidity and mortality, analyzed the entire expressed transcriptome in whole blood from children with non-SMA (Hb ≥ 6.0 g/dL, n = 41) and SMA (n = 25). Analyses revealed 3,420 up-regulated and 3,442 down-regulated transcripts, signifying impairments in host inflammasome activation, cell death, innate immune responses, and cellular stress responses in SMA. Immune cell profiling showed a decreased antigenic and immune priming response in children with SMA, favoring polarization toward cellular proliferation and repair. Enrichment analysis further identified altered neutrophil and autophagy-related processes, consistent with neutrophil degranulation and altered ubiquitination and proteasome degradation. Pathway analyses highlighted SMA-related alterations in cellular homeostasis, signaling, response to environmental cues, and cellular and immune stress responses. Validation with a qRT-PCR array showed strong concordance with the sequencing data. These findings identify key molecular themes in SMA pathogenesis, providing potential targets for new malaria therapies.

Nonsynonymous amino acid changes in the α-chain of complement component 5 influence longitudinal susceptibility to Plasmodium falciparum infections and severe malarial anemia in kenyan children.

Background: Severe malarial anemia (SMA; Hb < 5.0 g/dl) is a leading cause of childhood morbidity and mortality in holoendemic Plasmodium falciparum transmission regions such as western Kenya. Methods: We investigated the relationship between two novel complement component 5 (C5) missense mutations [rs17216529:C>T, p(Val145Ile) and rs17610:C>T, p(Ser1310Asn)] and longitudinal outcomes of malaria in a cohort of Kenyan children (under 60 mos, n = 1,546). Molecular modeling was used to investigate the impact of the amino acid transitions on the C5 protein structure. Results: Prediction of the wild-type and mutant C5 protein structures did not reveal major changes to the overall structure. However, based on the position of the variants, subtle differences could impact on the stability of C5b. The influence of the C5 genotypes/haplotypes on the number of malaria and SMA episodes over 36 months was determined by Poisson regression modeling. Genotypic analyses revealed that inheritance of the homozygous mutant (TT) for rs17216529:C>T enhanced the risk for both malaria (incidence rate ratio, IRR = 1.144, 95%CI: 1.059-1.236, p = 0.001) and SMA (IRR = 1.627, 95%CI: 1.201-2.204, p = 0.002). In the haplotypic model, carriers of TC had increased risk of malaria (IRR = 1.068, 95%CI: 1.017-1.122, p = 0.009), while carriers of both wild-type alleles (CC) were protected against SMA (IRR = 0.679, 95%CI: 0.542-0.850, p = 0.001). Conclusion: Collectively, these findings show that the selected C5 missense mutations influence the longitudinal risk of malaria and SMA in immune-naïve children exposed to holoendemic P. falciparum transmission through a mechanism that remains to be defined.

Defining the mechanisms of action and mosquito larva midgut response to a yeast-encapsulated orange oil larvicide.

BACKGROUND: Yeast-encapsulated orange oil (YEOO) is a novel, ingestible larvicide that combines the benefits of a low-cost essential oil with yeast, an attractive food source for mosquito larvae. In this work, we investigated the underlying mechanisms of action associated with YEOO ingestion by Aedes aegypti larvae. METHODS: Aedes aegypti third-stage larvae (L3) were treated with sublethal or lethal concentrations of YEOO. Genes associated with apoptosis, autophagy and innate immune responses were investigated by RT-qPCR in guts and carcasses dissected from treated and control larvae. Differential expression of cytochrome P450 genes in the CYP6 and CYP9 families were also investigated. Confocal and transmission electron microscopy were used to assess damage caused by YEOO throughout the larval alimentary canal. TUNEL was used to assess apoptosis via DNA fragmentation. RESULTS: The apoptosis genes IAP1 and IAP2 in larvae displayed opposing effects following exposure to lethal doses of YEOO, with a 26-fold induction of IAP1 at 8 h post YEOO ingestion. The effector caspase CASPS8 displayed a 6.7-fold induction in the gut and concomitant 70-fold induction in the carcass at 8 h post YEOO ingestion. The midgut epithelia regenerator, Vein, had an 11-fold induction in the gut after 4 h and was repressed 7.6-fold in the carcass at 24 h. Sublethal concentrations (< LC50) led to significant differential expression of CYP6 and CYP9 genes. Midgut epithelial damage was highlighted by the destruction of microvilli, vacuolization of midgut cells and damage to cell junctions and basal lamina as early as 30 min. Larval type 2 peritrophic matrix structural integrity and porosity remain unchanged. CONCLUSION: Our results strongly suggest that the robust larvicidal activity of YEOO is due to a generalized broad-acting mechanism combining epithelial damage and apoptosis, with concomitant expression of multiple innate response genes involved in epithelial regeneration and detoxification. YEOO's amenability for use as part of an integrated vector management program makes this novel larvicide a practical approach for mosquito larval control in the future.

Elevated SARS-CoV-2 in peripheral blood and increased COVID-19 severity in American Indians/Alaska Natives.

Epidemiological data across the United States show health disparities in COVID-19 infection, hospitalization, and mortality by race/ethnicity. While the association between elevated SARS-CoV-2 viral loads (VLs) (i.e. upper respiratory tract (URT) and peripheral blood (PB)) and increased COVID-19 severity has been reported, data remain largely unavailable for some disproportionately impacted racial/ethnic groups, particularly for American Indian or Alaska Native (AI/AN) populations. As such, we determined the relationship between SARS-CoV-2 VL dynamics and disease severity in a diverse cohort of hospitalized patients. Results presented here are for study participants (n = 94, ages 21-88 years) enrolled in a prospective observational study between May and October 2020 who had SARS-CoV-2 viral clades 20A, C, and G. Based on self-reported race/ethnicity and sample size distribution, the cohort was stratified into two groups: (AI/AN, n = 43) and all other races/ethnicities combined (non-AI/AN, n = 51). SARS-CoV-2 VLs were quantified in the URT and PB on days 0-3, 6, 9, and 14. The strongest predictor of severe COVID-19 in the study population was the mean VL in PB (OR = 3.34; P = 2.00 × 10-4). The AI/AN group had the following: (1) comparable co-morbidities and admission laboratory values, yet more severe COVID-19 (OR = 4.81; P = 0.014); (2) a 2.1 longer duration of hospital stay (P = 0.023); and (3) higher initial and cumulative PB VLs during severe disease (P = 0.025). Moreover, self-reported race/ethnicity as AI/AN was the strongest predictor of elevated PB VLs (ß = 1.08; P = 6.00 × 10-4) and detection of SARS-CoV-2 in PB (hazard ratio = 3.58; P = 0.004). The findings presented here suggest a strong relationship between PB VL (magnitude and frequency) and severe COVID-19, particularly for the AI/AN group.

Ingestion of hemozoin by peripheral blood mononuclear cells alters temporal gene expression of ubiquitination processes.

Plasmodium falciparum (Pf) malaria is among the leading causes of childhood morbidity and mortality worldwide. During a natural infection, ingestion of the malarial parasite product, hemozoin (PfHz), by circulating phagocytic cells induces dysregulation in innate immunity and enhances malaria pathogenesis. Treatment of cultured peripheral blood mononuclear cells (PBMCs) from healthy, malaria-naïve donors with physiological concentrations of PfHz can serve as an in vitro model to investigate cellular processes. Although disruptions in host ubiquitination processes are central to the pathogenesis of many diseases, this system remains unexplored in malaria. As such, we investigated the impact of PfHz on the temporal expression patterns of 84 genes involved in ubiquitination processes. Donor PBMCs were cultured in the absence or presence of PfHz for 3-, 9-, and 24 h. Stimulation with PfHz for 3 h did not significantly alter gene expression. Incubation for 9 h, however, elicited significant changes for 6 genes: 4 were down-regulated (FBXO4, NEDD8, UBE2E3, and UBE2W) and 2 were up-regulated (HERC5 and UBE2J1). PfHz treatment for 24 h significantly altered expression for 14 genes: 12 were down-regulated (ANAPC11, BRCC3, CUL4B, FBXO4, MIB1, SKP2, TP53, UBA2, UBA3, UBE2G1, UBE2G2, and WWP1), while 2 were up-regulated (UBE2J1 and UBE2Z). Collectively, these results demonstrate that phagocytosis of PfHz by PBMCs elicits temporal changes in the transcriptional profiles of genes central to host ubiquitination processes. Results presented here suggest that disruptions in ubiquitination may be a previously undiscovered feature of malaria pathogenesis.

Complement component 3 mutations alter the longitudinal risk of pediatric malaria and severe malarial anemia.

Severe malarial anemia (SMA) is a leading cause of childhood morbidity and mortality in holoendemic Plasmodium falciparum transmission regions. To gain enhanced understanding of predisposing factors for SMA, we explored the relationship between complement component 3 (C3) missense mutations [rs2230199 (2307C>G, Arg>Gly102) and rs11569534 (34420G>A, Gly>Asp1224)], malaria, and SMA in a cohort of children (n = 1617 children) over 36 months of follow-up. Variants were selected based on their ability to impart amino acid substitutions that can alter the structure and function of C3. The 2307C>G mutation results in a basic to a polar residue change (Arg to Gly) at position 102 (ß-chain) in the macroglobulin-1 (MG1) domain, while 34420G>A elicits a polar to acidic residue change (Gly to Asp) at position 1224 (α-chain) in the thioester-containing domain. After adjusting for multiple comparisons, longitudinal analyses revealed that inheritance of the homozygous mutant (GG) at 2307 enhanced the risk of SMA (RR = 2.142, 95%CI: 1.229-3.735, P = 0.007). The haplotype containing both wild-type alleles (CG) decreased the incident risk ratio of both malaria (RR = 0.897, 95%CI: 0.828-0.972, P = 0.008) and SMA (RR = 0.617, 95%CI: 0.448-0.848, P = 0.003). Malaria incident risk ratio was also reduced in carriers of the GG (Gly102Gly1224) haplotype (RR = 0.941, 95%CI: 0.888-0.997, P = 0.040). Collectively, inheritance of the missense mutations in MG1 and thioester-containing domain influence the longitudinal risk of malaria and SMA in children exposed to intense Plasmodium falciparum transmission.

Differential Gene Expression in Host Ubiquitination Processes in Childhood Malarial Anemia.

Background: Malaria remains one of the leading global causes of childhood morbidity and mortality. In holoendemic Plasmodium falciparum transmission regions, such as western Kenya, severe malarial anemia [SMA, hemoglobin (Hb) < 6.0 g/dl] is the primary form of severe disease. Ubiquitination is essential for regulating intracellular processes involved in innate and adaptive immunity. Although dysregulation in ubiquitin molecular processes is central to the pathogenesis of multiple human diseases, the expression patterns of ubiquitination genes in SMA remain unexplored. Methods: To examine the role of the ubiquitination processes in pathogenesis of SMA, differential gene expression profiles were determined in Kenyan children (n = 44, aged <48 mos) with either mild malarial anemia (MlMA; Hb ≥9.0 g/dl; n = 23) or SMA (Hb <6.0 g/dl; n = 21) using the Qiagen Human Ubiquitination Pathway RT2 Profiler PCR Array containing a set of 84 human ubiquitination genes. Results: In children with SMA, 10 genes were down-regulated (BRCC3, FBXO3, MARCH5, RFWD2, SMURF2, UBA6, UBE2A, UBE2D1, UBE2L3, UBR1), and five genes were up-regulated (MDM2, PARK2, STUB1, UBE2E3, UBE2M). Enrichment analyses revealed Ubiquitin-Proteasomal Proteolysis as the top disrupted process, along with altered sub-networks involved in proteasomal, protein, and ubiquitin-dependent catabolic processes. Conclusion: Collectively, these novel results show that protein coding genes of the ubiquitination processes are involved in the pathogenesis of SMA.

COVID-19 global pandemic planning: Presence of SARS-CoV-2 fomites in a university hospital setting.

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has surged across the globe, great effort has been expended to understand mechanisms of transmission and spread. From a hospital perspective, this topic is critical to limit and prevent SARS-CoV-2 iatrogenic transmission within the healthcare environment. Currently, the virus is believed to be transmitted primarily through respiratory droplets, but a growing body of evidence suggests that spread is also possible through aerosolized particles and fomites. Amidst a growing volume of patients with coronavirus disease 2019 (COVID-19), the purpose of this study was to evaluate the potential for SARS-CoV-2 transmission through fomites. Samples collected from the exposed skin of clinicians (n = 42) and high-touch surfaces (n = 40) were collected before and after encounters with COVID-19 patients. Samples were analyzed using two assays: the CDC 2019-nCoV Real-Time Reverse Transcription polymerase chain reaction (RT-qPCR) assay, and a SYBR Green assay that targeted a 121 bp region within the S-gene of SARS-CoV-2. None of the samples tested positive with the CDC assay, while two high-touch surface areas tested positive for SARS-CoV-2 using the Spike assay. However, viral culture did not reveal viable SARS-CoV-2 from the positive samples. Overall, the results from this study suggest that SARS-CoV-2 RNA were not widely present either on exposed skin flora or high-touch surface areas in the hospital locations tested. The inability to recover viable virus from samples that tested positive by the molecular assays, however, does not rule out the possibility of SARS-CoV-2 transmission through fomites.

High larvicidal efficacy of yeast-encapsulated orange oil against Aedes aegypti strains from Brazil.

BACKGROUND: Botanical substances such as essential oils (EOs) have demonstrated insecticidal properties and are a valid option for vector control. However, free EOs are unreliable as mosquito larvicides due their easy degradation by environmental exposure to ultraviolet light and higher temperatures. Here, we assessed the efficacy of a mosquito larvicide based on orange oil in a yeast-based delivery system against Aedes aegypti strains with different resistance status towards chemical neurotoxic insecticides. This larvicide preparation was physicochemically characterized in a previous report. METHODS: Larvae of four Ae. aegypti strains from different regions of Brazil and different resistance profiles for deltamethrin (pyrethroid) and temephos (organophosphate) were tested against yeast-encapsulated orange oil (YEOO) in laboratory conditions for measurement of LC50 and LC90 values. The same assays were performed with the Belo Horizonte strain under environmental conditions (natural light and temperature). The resistance profiles of these strains were compared to the Rockefeller reference strain in all conditions. RESULTS: YEOO was found to be a highly active larvicide (LC50 < 50 mg/L) against all Ae. aegypti strains tested in both laboratory conditions (LC50 = 8.1-24.7 mg/L) and environmental conditions with natural light and temperature fluctuation (LC50 = 20.0-49.9 mg/L). Moreover, all strains were considered susceptible (RR < 5) to YEOO, considering resistance ratios calculated based on the Rockefeller strain. The resistance ratios were only higher than 2.5 for LC90-95 of Belo Horizonte in the laboratory, probably due the higher heterogeneity associated with older egg papers (> 5 months). CONCLUSION: YEOO demonstrates high larvicidal activity against Ae. aegypti strains with resistant phenotypes for deltamethrin (PY) and temephos (OP). This larvicidal activity suggests the potential for the development of YEOO as an alternative intervention to synthetic insecticides in integrated vector management programs, for populations with resistance to commonly used insecticides.

A computer-aided approach to identify novel Leishmania major protein disulfide isomerase inhibitors for treatment of leishmaniasis.

Leishmaniasis is an infectious disease caused by parasites of the genus Leishmania and transmitted by the bite of a sand fly. To date, most available drugs for treatment are toxic and beyond the economic means of those affected by the disease. Protein disulfide isomerase (PDI) is a chaperone protein that plays a major role in the folding of newly synthesized proteins, specifically assisting in disulfide bond formation, breakage, or rearrangement in all non-native proteins. In previous work, we demonstrated that Leishmania major PDI (LmPDI) has an essential role in pathogen virulence. Furthermore, inhibition of LmPDI further blocked parasite infection in macrophages. In this study, we utilized a computer-aided approach to design a series of LmPDI inhibitors. Fragment-based virtual screening allowed for the understanding of the inhibitors' modes of action on LmPDI active sites. The generated compounds obtained after multiple rounds of virtual screening were synthesized and significantly inhibited target LmPDI reductase activity and were shown to decrease in vitro parasite growth in human monocyte-derived macrophages. This novel cheminformatics and synthetic approach led to the identification of a new series of compounds that might be optimized into novel drugs, likely more specific and less toxic for the treatment of leishmaniasis.

COVID-19 global pandemic planning: Dry heat incubation and ambient temperature fail to consistently inactivate SARS-CoV-2 on N95 respirators.

The ongoing pandemic of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has placed a substantial strain on the supply of personal protective equipment, particularly the availability of N95 respirators for frontline healthcare personnel. These shortages have led to the creation of protocols to disinfect and reuse potentially contaminated personal protective equipment. A simple and inexpensive decontamination procedure that does not rely on the use of consumable supplies is dry heat incubation. Although reprocessing with this method has been shown to maintain the integrity of N95 respirators after multiple decontamination procedures, information on the ability of dry heat incubation to inactivate SARS-CoV-2 is largely unreported. Here, we show that dry heat incubation does not consistently inactivate SARS-CoV-2-contaminated N95 respirators, and that variation in experimental conditions can dramatically affect viability of the virus. Furthermore, we show that SARS-CoV-2 can survive on N95 respirators that remain at room temperature for at least five days. Collectively, our findings demonstrate that dry heat incubation procedures and ambient temperature for five days are not viable methods for inactivating SARS-CoV-2 on N95 respirators for potential reuse. We recommend that decontamination procedures being considered for the reuse of N95 respirators be validated at each individual site and that validation of the process must be thoroughly conducted using a defined protocol.

COVID-19 global pandemic planning: Performance and electret charge of N95 respirators after recommended decontamination methods.

Shortages of N95 respirators for use by medical personnel have driven consideration of novel conservation strategies, including decontamination for reuse and extended use. Decontamination methods listed as promising by the Centers for Disease Control and Prevention (CDC) (vaporous hydrogen peroxide (VHP), wet heat, ultraviolet irradiation (UVI)) and several methods considered for low resource environments (bleach, isopropyl alcohol and detergent/soap) were studied for two commonly used surgical N95 respirators (3M™ 1860 and 1870+ Aura™). Although N95 filtration performance depends on the electrostatically charged electret filtration layer, the impact of decontamination on this layer is largely unexplored. As such, respirator performance following decontamination was assessed based on the fit, filtration efficiency, and pressure drop, along with the relationship between (1) surface charge of the electret layer, and (2) elastic properties of the straps. Decontamination with VHP, wet heat, UVI, and bleach did not degrade fit and filtration performance or electret charge. Isopropyl alcohol and soap significantly degraded fit, filtration performance, and electret charge. Pressure drop across the respirators was unchanged. Modest degradation of N95 strap elasticity was observed in mechanical fatigue testing, a model for repeated donnings and doffings. CDC recommended decontamination methods including VHP, wet heat, and UV light did not degrade N95 respirator fit or filtration performance in these tests. Extended use of N95 respirators may degrade strap elasticity, but a loss of face seal integrity should be apparent during user seal checks. NIOSH recommends performing user seal checks after every donning to detect loss of appropriate fit. Decontamination methods which degrade electret charge such as alcohols or detergents should not be used on N95 respirators. The loss of N95 performance due to electret degradation would not be apparent to a respirator user or evident during a negative pressure user seal check.

Severe Acute Respiratory Syndrome Coronavirus 2 Neutralizing Antibody Titers in Convalescent Plasma and Recipients in New Mexico: An Open Treatment Study in Patients With Coronavirus Disease 2019.

BACKGROUND: Convalescent plasma (CP) is a potentially important therapy for coronavirus disease 2019 (COVID-19). However, knowledge regarding neutralizing antibody (NAb) titers in donor plasma and their impact in patients with acute COVID-19 remains largely undetermined. We measured NAb titers in CP and in patients with acute COVID-19 before and after transfusion through the traditional Food and Drug Administration investigational new drug pathway. METHODS: We performed a single-arm interventional trial measuring NAb and total antibody titers before and after CP transfusion over a 14-day period in hospitalized patients with laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection. RESULTS: NAb titers in the donor CP units were low (<1:40 to 1:160) and had no effect on recipient neutralizing activity 1 day after transfusion. NAb titers were detected in 6 of 12 patients on enrollment and in 11 of 12 at ≥2 time points. Average titers peaked on day 7 and declined toward day 14 (P = .004). Nab titers and immunoglobulin G levels were correlated in donor plasma units (ρ = 0.938; P < .001) and in the cumulative patient measures (ρ = 0.781; P < .001). CONCLUSIONS: CP infusion did not alter recipient NAb titers. Prescreening of CP may be necessary for selecting donors with high titers of neutralizing activity for infusion into patients with COVID-19. CLINICAL TRIALS REGISTRATION: NCT04434131.

COVID-19 global pandemic planning: Decontamination and reuse processes for N95 respirators.

IMPACT STATEMENT: There is a critical shortage of personal protective equipment (PPE) around the globe. This article describes the safe collection, storage, and decontamination of N95 respirators using hydrogen peroxide vapor (HPV). This article is unique because it describes the HPV process in an operating room, and is therefore, a deployable method for many healthcare settings. Results presented here offer creative solutions to the current PPE shortage.

Yeast-encapsulated essential oils: a new perspective as an environmentally friendly larvicide.

BACKGROUND: Effective mosquito control approaches incorporate both adult and larval stages. For the latter, physical, biological, and chemical control have been used with varying results. Successful control of larvae has been demonstrated using larvicides including insect growth regulators, e.g. the organophosphate temephos, as well as various entomopathogenic microbial species. However, a variety of health and environmental issues are associated with some of these. Laboratory trials of essential oils (EO) have established the larvicidal activity of these substances, but there are currently no commercially available EO-based larvicides. Here we report on the development of a new approach to mosquito larval control using a novel, yeast-based delivery system for EO. METHODS: Food-grade orange oil (OO) was encapsulated into yeast cells following an established protocol. To prevent environmental contamination, a proprietary washing strategy was developed to remove excess EO that is adsorbed to the cell exterior during the encapsulation process. The OO-loaded yeast particles were then characterized for OO loading, and tested for efficacy against Aedes aegypti larvae. RESULTS: The composition of encapsulated OO extracted from the yeast microparticles was demonstrated not to differ from that of un-encapsulated EO when analyzed by high performance liquid chromatography. After lyophilization, the oil in the larvicide comprised 26-30 percentage weight (wt%), and is consistent with the 60-65% reduction in weight observed after the drying process. Quantitative bioassays carried with Liverpool and Rockefeller Ae. aegypti strains in three different laboratories presented LD50 of 5.1 (95% CI: 4.6-5.6) to 27.6 (95% CI: 26.4-28.8) mg/l, for L1 and L3/L4 mosquito larvae, respectively. LD90 ranged between 18.9 (95% CI: 16.4-21.7) mg/l (L1 larvae) to 76.7 (95% CI: 69.7-84.3) mg/l (L3/L4 larvae). CONCLUSIONS: The larvicide based on OO encapsulated in yeast was shown to be highly active (LD50 < 50 mg/l) against all larval stages of Ae. aegypti. These results demonstrate its potential for incorporation in an integrated approach to larval source management of Ae. aegypti. This novel approach can enable development of affordable control strategies that may have significant impact on global health.

Integrated OMICS platforms identify LAIR1 genetic variants as novel predictors of cross-sectional and longitudinal susceptibility to severe malaria and all-cause mortality in Kenyan children.

BACKGROUND: Severe malarial anaemia (SMA) is a leading cause of childhood mortality in holoendemic Plasmodium falciparum regions. METHODS: To gain an improved understanding of SMA pathogenesis, whole genome and transcriptome profiling was performed in Kenyan children (n=144, 3-36months) with discrete non-SMA and SMA phenotypes. Leukocyte associated immunoglobulin like receptor 1 (LAIR1) emerged as a predictor of susceptibility to SMA (P<1×10-2, OR: 0.44-1.37), and was suppressed in severe disease (-1.69-fold, P=0.004). To extend these findings, the relationship between LAIR1 polymorphisms [rs6509867 (16231C>A); rs2287827 (18835G>A)] and clinical outcomes were investigated in individuals (n=1512, <5years) at enrolment and during a 36-month longitudinal follow-up. FINDINGS: Inheritance of the 16,231 recessive genotype (AA) increased susceptibility to SMA at enrolment (OR=1.903, 95%CI: 1.252-2.891, P=0.003), and longitudinally (RR=1.527, 95%CI: 1.119-2.083, P=0.008). Carriage of the 18,835 GA genotype protected against SMA cross-sectionally (OR=0.672, 95%CI: 0.480-0.9439, P=0.020). Haplotype carriage (C16231A/G18835A) also altered cross-sectional susceptibility to SMA: CG (OR=0.717, 95%CI: 0.527-0.9675, P=0.034), CA (OR=0.745, 95%CI: 0.536-1.036, P=0.080), and AG (OR=1.641, 95%CI: 1.160-2.321, P=0.005). Longitudinally, CA carriage was protective against SMA (RR=0.715, 95%CI: 0.554-0.923, P=0.010), while AG carriage had an additive effect on enhanced SMA risk (RR=1.283, 95%CI: 1.057-1.557, P=0.011). Variants that protected against SMA had elevated LAIR1 transcripts, while those with enhanced risk had lower expression (P<0.05). Inheritance of 18,835 GA reduced all-cause mortality by 44.8% (HR=0.552, 95%CI: 0.329-0.925, P=0.024), while AG haplotype carriage increased susceptibility by 68% (HR=1.680, 95%CI: 1.020-2.770, P=0.040). INTERPRETATION: These findings suggest LAIR1 is important for modulating susceptibility to SMA and all-cause childhood mortality.

Characterization of a Lactococcus lactis promoter for heterologous protein production.

Constitutively active promoter elements for heterologous protein production in Lactococcus lactis are scarce. Here, the promoter of the PTS-IIC gene cluster from L. lactis NZ3900 is described. This promoter was cloned upstream of an enhanced green fluorescent protein, GFPmut3a, and transformed into L. lactis. Transformants produced up to 13.5 µg of GFPmut3a per milliliter of log phase cells. Addition of cellobiose further increased the production of GFPmut3a by up to two-fold when compared to glucose. Analysis of mutations at two specific positions in the PTS-IIC promoter showed that a 'T' to 'G' mutation within the -35 element resulted in constitutive expression in glucose, while a 'C' at nucleotide 7 in the putative cre site enhanced promoter activity in cellobiose. Finally, this PTS-IIC promoter is capable of mediating protein expression in Bacillus subtilis and Escherichia coli Nissle 1917, suggesting the potential for future biotechnological applications of this element and its derivatives.