Major Host Research Articles

Influence of Holding Major Sports Events on Urban Economy

Last year's Tokyo Olympics had a great impact on the host country's economy. Due to various reasons, this Olympics has caused a lot of losses. Now the 2022 Qatar World Cup is coming as scheduled, and the Qatar World Cup cost more than 200 billion U.S. dollars, making it the most expensive one. At that time, people from all over the world will come here. Of course, it will bring about the development of related industries and positive benefits, but it is still unknown whether it can help the host country make profits and whether it will have any adverse effects on the economy. To this end, the post-match income of major sports events over the years, especially the Olympic Games and the World Cup, has been searched and studied. In the end it was found that very little turned out to be profitable. Not only would most cities lose money, but the stadiums would be abandoned. A profitable experience was found through the success of several major hosts.

Hospital evacuation in large-scale disasters using limited aerial transport resources

Hospitals play a key role in providing medical assistance in a post-disaster phase. However, depending on the nature, scale, and severity of disasters, they may also be affected and may need to evacuate their patients. Current evacuation response plans for hospitals are predominantly based on the use of land vehicles, whereas little methodological advancements have been reported for when aerial hospital evacuations become necessary. To address this problem, this study develops a model that facilitates evacuation planning for moving patients from at-risk hospitals to remote locations using limited aerial transportation resources. A subset of the model parameters is treated as stochastic in order to reflect the uncertainties involved in real-world emergency conditions. The complexities of the model are handled via the use of a metaheuristic approach, the Variable neighbourhood search (VNS) algorithm, to provide a suitable solution within a reasonable amount of time. A relaxed mathematical model is used in the proposed VNS to generate an initial solution, which is then transformed into a feasible solution through a try-and-error procedure. The proposed method applies a reinforcement learning procedure that uses different local search strategies within the loop of the VNS. A hypothetical evacuation scenario of real-life scale, from an island state in Australia to the mainland states, is used to evaluate the ability of the model to generate efficient plans. In this case study, Tasmania is considered as an evacuation point, while hospitals located in other major cities host evacuated patients. Comparing the proposed method with a conventional method shows superior performance based on all relevant metrics. Emergency response agencies across many countries that can adopt the proposed methodology, when facing large-scale emergencies caused by wars, epidemics, or natural hazards such as wildfires and earthquakes.

Tungsten mineralization formed by single-pulsed magmatic fluid: Evidence from wolframite-hosted fluid inclusion from the giant Dajishan “five floor” style W-polymetallic deposit

The giant Dajishan W-polymetallic deposit, located in the Nanling metallogenic belt, is a typical steeply dipping wolframite-quartz vein-type deposit. From top to bottom, the W ore grade is highest in the middle and decreases towards both ends. In No. 23 wolframite-quartz vein of the north group, the thickness of the veins increases from 0.1 ∼ 0.2 m thick in the 517 m level to a maximum of 0.6 ∼ 2.0 m in the 267 m level. According to the “Five Floor” prospecting model, the No. 23 vein corresponds to veinlet (517 m), moderate vein (467 ∼ 417 m), and thick vein zones (367 m ∼ 267 m). Primary wolframite-hosted fluid inclusions show homogenization temperatures display a slight but explicit decrease by about 20 °C in average from bottom to top, recording the essential fluid cooling process. The phase ratios (20 to 30 vol% vapor proportions) and salinities (6.3 to 10.0 wt% NaCl equiv.) are constant at all levels, indicating that neither meteoric water mixing nor fluid boiling/immiscibility is obvious during wolframite formation. The fluids contain NaCl and KCl as major salts, B as the subordinate component, with trace elements including Li, Rb, Cs, Zn, Pb, etc. The significant narrow ranges of K/Na (0.296 to 0.664), Rb/Na (0.008 to 0.018), and Cs/Na ratios (0.032 to 0.076) illustrate that wolframite ore-forming fluids come from the initial fluids derived from a highly-evolved granitic magma. In major host metasandstone, muscovitization and tourmalinization lead to the release of Na, B, and Al from the fluid into the wall rock, and liberation of Fe from the wall rock into the fluid. Wall rock composition data show that muscovitization is the main mechanism of changes in Fe contents. Preliminary calculations indicate that fluid-rock interaction may contributes minor iron to the ore-forming fluids. Combining these results, we support that “Five Floor” style W mineralization in Dajishan is formed by a single-pulsed magmatic fluid. The vertical zonation of vein thickness and ore grade in the “Five Floor” model is predominately controlled by temperature, pressure, and local tectonic regime, but it is less dependent on the fluid chemical composition.

Morphological and Phylogenetic Analyses Reveal Three New Species of Distoseptispora (Distoseptisporaceae, Distoseptisporales) from Yunnan, China.

Three new species of Distoseptispora, viz. D. mengsongensis, D. nabanheensis, and D. sinensis, are described and illustrated from specimens collected on dead branches of unidentified plants in Yunnan Province, China. Phylogenetic analyses of LSU, ITS, and TEF1 sequence data, using maximum-likelihood (ML) and Bayesian inference (BI), reveal the taxonomic placement of D. mengsongensis, D. nabanheensis, and D. sinensis within Distoseptispora. Both morphological observations and molecular phylogenetic analyses supported D. mengsongensis, D. nabanheensis, and D. sinensis as three new taxa. To extend our knowledge of the diversity of Distoseptispora-like taxa, a list of recognized species of Distoseptispora with major morphological features, habitat, host, and locality is also provided.

Metagenomic analysis reveals the short-term influences on conjugation of blaNDM-1 and microbiome in hospital wastewater by silver nanoparticles at environmental-related concentration

Hospital wastewater contains large amounts of antibiotic-resistant bacteria and serves as an important reservoir for horizontal gene transfer (HGT). However, the response of the microbiome in hospital wastewater to silver remains unclear. In this study, the short-term impacts of silver on the microbiome in hospital wastewater were investigated by metagenome next-generation sequencing. The influence of silver on the conjugation of plasmid carrying blaNDM-1 was further examined. Our results showed that in hospital wastewater, high abundances of antibiotic resistance genes (ARGs) were detected. The distribution tendencies of certain ARG types on chromosomes or plasmids were different. Clinically important ARGs were identified in phage-like contigs, indicating potential transmission via transduction. Pseudomonadales, Enterobacterales, and Bacteroidales were the major ARG hosts. Mobile genetic elements were mainly detected in plasmids and associated with various types of ARGs. The binning approach identified 29 bins that were assigned to three phyla. Various ARGs and virulence factors were identified in 14 and 11 bins, respectively. MetaCHIP identified 49 HGT events. The transferred genes were annotated as ARGs, mobile genetic elements, and functional genes, and they mainly originated from donors belonging to Bacteroides and Pseudomonadales. In addition, 20 nm AgNPs reduced microbial diversity and enhanced the relative abundance of Acinetobacter. The changes induced by 20 nm AgNPs included increases in the abundances of ARGs and genes involved lipid metabolism pathway. Conjugation experiments showed that Ag+ and 20 nm AgNPs caused 2.38-, 3.31-, 4.72-, and 4.57-fold and 1.46-, 1.61-, 3.86-, and 2.16-fold increases in conjugation frequencies of plasmid with blaNDM-1 at 0.1, 1, 10, and 100 μg/L, respectively. Our findings provide insight into the response of the microbiome in hospital wastewater to silver, emphasize the adaptation capability of Acinetobacter inhabiting hospitals against adverse environments, and highlight the promotion of silver for antibiotic resistance.

Abstract 1361: Astrocytes activate neuronal programming in melanoma brain metastases

Abstract Melanoma Brain Metastases (MBM) pose a major challenge for treating metastatic melanoma. Up to 70% of advanced melanoma patients develop MBM, resulting in significant morbidity and mortality. Melanocytes, the originating cell type of melanomas, are derived from neural crest cells in development. Melanoma’s proclivity to metastasize to the brain has been anecdotally connected to its neural crest origins. Recently, transcriptomic analyses have demonstrated that MBM express a neuronal-like phenotype, upregulating neural crest factors such as NCAM (Neural cell adhesion molecule), L1CAM (L1 cell adhesion molecule protein), while expressing melanocytic markers like MITF (melanocyte induction transcription factor). The activation of neuronal development programming may be a key mediator in brain-metastatic growth, and thus necessitates a better understanding of how melanoma cells adapt to the brain. Astrocytes have emerged as the major host cell type that cancer cells encounter and interact with during brain metastasis formation. Typically, astrocytes regulate brain homeostasis and support neuronal function. Their response to injury, termed reactive astrocytosis, is a process defined by increased secretion of growth factors and inflammatory cytokine production. Post-mortem analyses of MBM patients reveal perilesional reactive astrocytosis. Here we demonstrate that astrocyte reactivity promotes MBM growth, using in vitro and in vivo model systems. We identify that astrocytes secrete factors that increase tumor growth and expression of neural development factors. Moreover, pharmacological inhibition of neural development pathways, like Wnt signaling, attenuate the effects of astrocyte secreted factors. We developed a brain adapted melanoma line, D4M3a BrJ, and demonstrate the time course of astrocyte reactivity in vivo in its relationship with tumor growth. Our findings provide evidence that astrocyte reactivity promotes MBM growth and activation of neural development programming, unveiling a new therapeutic avenue for targeting the brain metastatic niche. Citation Format: Julia K. Farnan, Maria R. Cavallo, Edward J. Hartsough, Joshua G. Jackson. Astrocytes activate neuronal programming in melanoma brain metastases [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1361.

Investment policy reform as a driver of foreign direct investment: Evidence from China

AbstractA longstanding concern has been the proposition that the international investment treaty system lacks reform. Governments forgo Foreign Direct Investment (FDI) and thus forgo a driver of economic growth, employment and innovation. We assess the validity of this concern in the context of a major home and host country for global foreign direct investment, China, and the major reform of its Bilateral Investment Treaties (BITs). Besides other innovations, the so‐called ‘third‐generation’ BITs of China introduce a strong dispute resolution mechanism, which makes Chinese BITs more investor‐friendly. Our evidence suggests that more investor‐friendly BITs exert a positive impact on FDI in China. We argue that the positive impact of reforming BITs in a country like China, which offers a high degree of stability of the legal and political system and a strong culture of informal dispute resolution, points towards the relevance of the enforceability of property rights for investments.

LNCGM1082-mediated NLRC4 activation drives resistance to bacterial infection.

The activation of NLRC4 is a major host response against intracellular bacteria infection. However, NLRC4 activation after a host senses diverse stimuli is difficult to understand. Here, we found that the lncRNA LNCGM1082 plays a critical role in the activation of NLRC4. LNCGM1082 in macrophages affects the maturation of interleukin (IL)-1β and pyroptotic cell death only after exposure to an NLRC4 ligand. Similar to NLRC4-/- mice, LNCGM1082-/- mice were highly sensitive to Salmonella Typhimurium (S. T) infection. LNCGM1082 deficiency in mouse or human macrophages inhibited IL-1β maturation and pyroptosis. Mechanistically, LNCGM1082 induced the binding of PKCδ with NLRC4 in both mice and humans. In contrast, NLRC4 did not bind PKCδ in LNCGM1082-/- macrophages. The activity of the lncRNA LNCGM1082 induced by S. T may be mediated through TLR5 in the macrophages of both mice and humans. In summary, our data indicate that TLR5-mediated LNCGM1082 activity can promote the binding of PKCδ with NLRC4 to activate NLRC4 and induce resistance to bacterial infection.

Integrated approaches for the separation and purification of recombinant HPV16 E6 protein from Escherichia coli crude extracts

Human papillomavirus (HPV) is a sexually transmissible virus responsible for 5% of global human cancers and associated with 99% of cervical cancer cases. The oncogenic potential of high-risk HPVs is mainly related to the E6 and E7 oncoproteins, which are responsible, at least in part, for inactivating the p53 and pRb tumor suppressor proteins. Due to the critical role of the E6 protein in malignant tumorigenesis, it is widely recognized as a therapeutic target for anti-HPV drug development. Nevertheless, it is required to obtain large amounts of protein with high purity to perform biointeraction studies with the potential inhibitor drugs. In this work, recombinant dual-tagged E6 protein (His6-MBP-E6) was expressed from Escherichia coli (E. coli) cultures and successfully extracted by sonication/ice cycles. Affinity chromatography using MBPtrap columns allowed 85 ± 5% protein recovery with the elimination of major host heterologous proteins in a single fraction. Subsequently, a polishing step was studied by applying anionic exchange (QSepharose), size exclusion (Superdex), or immobilized-metal affinity chromatography (HisTrap). The combination of affinity chromatography with size exclusion or two affinity chromatography techniques allowed us to obtain 82 ± 2% and 94 ± 3%, of highly pure His6-MBP-E6, respectively. Also, the secondary structure of His6-MBP-E6 is preserved in both purification strategies, as appraised by circular dichroism and western-blot studies. Thermal shift assay confirmed the CD results and suggested potential additives for protein stabilization. Altogether, the reproducible strategies established for the purification of His6-MBP-E6 protein could be successfully applied to later perform biointeraction studies and structural characterization of protein–ligand complexes.

Dynamic Changes in Antibiotic Resistance Genes During Biological Fermentation of Chicken Manure and Pig Manure

Livestock manure is a major carrier that stores and transmits antibiotic resistance genes (ARGs). The aim of this study was to identify the crucial environmental factors that result in the change in relative abundance of ARGs and MGEs to explore effective methods to reduce the occurrence of ARGs. The abundance of ten ARGs and five MGEs were measured using real-time quantitative PCR with 0, 3, 7, 10, 14, 21, 28, 45, 60, and 75 d in CM and PM aerobic composting. The succession law of the bacterial community was analyzed using 16S rRNA high-throughput sequencing. Furthermore, the abundance of ARGs and MGEs was correlated with the properties (temperature, moisture content, pH, and DOC) of composting piles to identify the crucial factors affecting the variation in ARGs and MGEs. The results showed that the abundance of ARGs and MGEs in PM was higher than that in CM. Composting significantly reduced the relative abundance of nine ARGs and five MGEs. The removal ratios of three ARGs (tetM, tetT, and aacA) and four MGEs (ISEcp1, IS1216, IS613, and tnp614) in CM reached 99%. The removal ratios of nine ARGs[tetB(P), tetL, tetM, tetO, tetT, aacA, aadD,aphA3, and sat4] and four MGEs (ISEcp1, IS26, IS1216, and tnp614) reached 99% in PM. However, the abundance of the genes tetG, intI1, and IS6100 increased. Firmicutes and Actinobacteria were dominant in CM and PM during composting. Actinobacteria and Proteobacteria may have been the major host bacteria of tetG and intI1. The redundancy analysis showed that moisture and pH were the crucial factors that could influence the differences in the abundance of ARGs and MGEs. The composition and abundance of ARGs were driven by physicochemical properties, bacterial community, and MGEs. Composting could significantly reduce the abundance of ARGs in CM and PM, thus reducing the risk of ARGs being distributed via livestock manure application. However, some ARGs and MGEs remained in high abundance. Therefore, it is necessary to further optimize the composting process, improve the harmless treatment effect of livestock manure, and promote the safe agricultural use of organic fertilizers.

Cell membrane-coated nanoparticles: An emerging antibacterial platform for pathogens of food animals.

Bacterial pathogens of animals impact food production and human health globally. Food animals act as the major host reservoirs for pathogenic bacteria and thus are highly prone to suffer from several endemic infections such as pneumonia, sepsis, mastitis, and diarrhea, imposing a major health and economical loss. Moreover, the consumption of food products of infected animals is the main route by which human beings are exposed to zoonotic bacteria. Thus, there is excessive and undue administration of antibiotics to fight these virulent causative agents of food-borne illness, leading to emergence of resistant strains. Thus, highprevalence antibiotic-resistant resistant food-borne bacterial infections motivated the researchers to discover new alternative therapeutic strategies to eradicate resistant bacterial strains. One of the successful therapeutic approach for the treatment of animal infections, is the application of cell membrane-coated nanoparticles. Cell membranes of several different types of cells including platelets, red blood cells, neutrophils, cancer cells, and bacteria are being wrapped over the nanoparticles to prepare biocompatible nanoformulations. This diversity of cell membrane selection and together with the possibility of combining with an extensive range of nanoparticles, has opened a new opportunistic window for the development of more potentially effective, safe, and immune evading nanoformulations, as compared to conventionally used bare nanoparticle. This article will elaborately discuss the discovery and development of novel bioinspired cell membrane-coated nanoformulations against several pathogenic bacteria of food animals such as Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Salmonella enteritidis, Campylobacter jejuni, Helicobacter pylori, and Group A Streptococcus and Group B Streptococcus.

Development of an Inactivated Avian Influenza Virus Vaccine against Circulating H9N2 in Chickens and Ducks.

Avian influenza virus (AIV) subtype H9N2 is the most widespread AIV in poultry worldwide, causing great economic losses in the global poultry industry. Chickens and ducks are the major hosts and play essential roles in the transmission and evolution of H9N2 AIV. Vaccines are considered an effective strategy for fighting H9N2 infection. However, due to the differences in immune responses to infection, vaccines against H9N2 AIV suitable for use in both chickens and ducks have not been well studied. This study developed an inactivated H9N2 vaccine based on a duck-origin H9N2 AIV and assessed its effectiveness in the laboratory. The results showed that the inactivated H9N2 vaccine elicited significant haemagglutination inhibition (HI) antibodies in both chickens and ducks. Virus challenge experiments revealed that immunization with this vaccine significantly blocked virus shedding after infection by both homogenous and heterologous H9N2 viruses. The vaccine was efficacious in chicken and duck flocks under normal field conditions. We also found that egg-yolk antibodies were produced by laying birds immunized with the inactivated vaccine, and high levels of maternal antibodies were detected in the serum of the offspring. Taken together, our study showed that this inactivated H9N2 vaccine could be extremely favourable for the prevention of H9N2 in both chickens and ducks.

Land-use changes interact with geology to facilitate dispersal of the rock hyrax (Procavia capensis) and leishmaniasis across Israel and the West Bank.

Geology plays a fundamental role in establishing species' habitats, determining both physical (e.g., landscape morphology, soil texture) and chemical (e.g., mineral composition, water availability) properties. In the current Anthropocene epoch, human activity is transforming Earth's geology and ecosystems. Yet to date, there have been almost no studies incorporating geology when examining the effect of such land-use changes on species distribution. This study seeks to uncover how specific land-use changes interact with geology, in order to explain the recent and rapid expansion of the rock hyrax (Procavia capensis) across the mountains of central Israel and the West Bank. Hyraxes are dependent on rock mounds for their habitat, and their expansion seems to be correlated with increasing infrastructure construction. However, their expansion patterns differ among locations, even when the human land-use is similar. To explain the patterns of hyrax distribution observed over the past 46 years, we converted geological data into ecological data, which present the probability of the local bedrock breaking into boulders, whether due to either natural or anthropogenic weathering processes. We applied species distribution models (SDMs) and found that the expansion of rock hyrax populations was facilitated by means of the interaction of specific geological units with land-use practices (e.g., roads and construction), which resulted in the accumulation of large boulders, creating novel habitats and stepping stones in previously unsuitable areas for hyraxes. Since rock hyraxes are major hosts of the leishmaniasis pathogen, the findings from this study offer important insights into the progression and potential outbreaks of the disease in human populations. Understanding the role that geology plays in shaping a species' niche is expected to prove useful in studying the distribution of other wildlife species and is fundamental in studies seeking to predict the potential ecological impacts on local biodiversity associated with land-use change.

Acid pressure oxidation leaching of arsenopyrite in the presence of pyrite: Oxygen consumption kinetics

In the process of extraction of gold from refractory sulphide ores, arsenopyrite and pyrite represent two of the major hosts for gold in solid solution. In this study, the pressure oxidation of arsenopyrite and arsenopyrite-pyrite mixtures in a H2SO4–O2 system have been investigated, with the aim of using the oxygen consumption kinetics to probe the oxidation mechanisms. The effects of temperature (180–220 °C), acidity (pH 0.5–2.5), dissolved iron concentration (10 and 30 g/L) and molar ratios (0:1–3:1) of pyrite-to-arsenopyrite (Py/Aspy) were evaluated. Kinetic analysis of arsenopyrite dissolution at 180–220 °C via a shrinking core model indicated an activation energy (Ea) of 48.46 kJ/mol, suggesting a mixed interface reaction and diffusion control. The order of the reaction to acidity was 0.16 at 200 °C, suggesting that [H+] is likely not the rate-limiting factor under typical reaction conditions. The addition of Fe(II) ions to the feed enhanced arsenopyrite oxidation, due to the formation of Fe(III) as a surrogate oxidant to drive the reaction.The Ea for Py/Aspy of 1:1 exhibited two behaviours, calculated to be 77.32 kJ/mol below 200 °C and decreasing to 34.59 kJ/mol above 200 °C. The former was attributed to surface control due to the oxidation of elemental sulphur, followed by a switch to mixed control at elevated temperatures. As Py/Aspy was increased to 2:1 and 3:1, a single behaviour was observed, with Ea values of 56.01 kJ/mol and 43.35 kJ/mol respectively. These values imply a mixed control and begin to approximate literature values for pyrite oxidation. A time-to-a-given-fraction method was also used to examine changes in Ea with reaction extent. Arsenopyrite was found to be under mixed control for most of the reaction extent. At increasing pyrite fractions, oxidation was observed to be reaction-limited at the initial stage of reaction, potentially reflecting the kinetics of sulphur oxidation.

Can Antibiotic Resistance Genes in Household Food Waste be Reduced by Earthworm Vermicomposting? Underpinning Mechanisms and Strategies

Hundreds of million tons of food waste (FW) is annually generated from the household sectors. Also, it is regarded as a main conduit for the spread of antibiotic resistance genes (ARGs) in the ‘human–environment’ loop. This paper mainly reviews recent studies on the occurrence and dynamics of ARGs in FW and discusses the ins, outs, and spreads of ARGs by the vermicomposting. Our analysis shows that the concentration of FW-borne ARGs and their major hosts (human pathogens) can be effectively reduced and eliminated in the earthworm guts, respectively, due to the increased bacterial fitness cost for ARG-spreading and earthworm immune responses. Of particular interest, the removal performance could be improved by the measures including agricultural waste co-composting and enforced aeration, which concurrently lead to an elevated vermicomposting loading rate and enhanced quality of compost end-products. Furthermore, our review argues that functional microbial inoculum-feeding possibly results in microbial colonization and stable reproduction in earthworm guts. This proposed optimization approach may be instrumental to contain the spread of ARGs and increase the vermicomposting treatment efficiency at the same time.

Orthopoxvirus Zoonoses—Do We Still Remember and Are Ready to Fight?

The eradication of smallpox was an enormous achievement due to the global vaccination program launched by World Health Organization. The cessation of the vaccination program led to steadily declining herd immunity against smallpox, causing a health emergency of global concern. The smallpox vaccines induced strong, humoral, and cell-mediated immune responses, protecting for decades after immunization, not only against smallpox but also against other zoonotic orthopoxviruses that now represent a significant threat to public health. Here we review the major aspects regarding orthopoxviruses' zoonotic infections, factors responsible for viral transmissions, as well as the emerging problem of the increased number of monkeypox cases recently reported. The development of prophylactic measures against poxvirus infections, especially the current threat caused by the monkeypox virus, requires a profound understanding of poxvirus immunobiology. The utilization of animal and cell line models has provided good insight into host antiviral defenses as well as orthopoxvirus evasion mechanisms. To survive within a host, orthopoxviruses encode a large number of proteins that subvert inflammatory and immune pathways. The circumvention of viral evasion strategies and the enhancement of major host defenses are key in designing novel, safer vaccines, and should become the targets of antiviral therapies in treating poxvirus infections.

Morphology and Multigene Phylogeny Revealed Three New Species of Helminthosporium (Massarinaceae, Pleosporales) from China

Saprobic hyphomycetes are highly diverse on plant debris. Over the course of our mycological surveys in southern China, three new Helminthosporium species, H. guanshanense sp. nov., H. jiulianshanense sp. nov. and H. meilingense sp. nov., collected on dead branches of unidentified plants, were introduced by morphological and molecular phylogenetic analyses. Multi-loci (ITS, LSU, SSU, RPB2 and TEF1) phylogenetic analyses were performed using maximum-likelihood and Bayesian inference to infer their taxonomic positions within Massarinaceae. Both molecular analyses and morphological data supported H. guanshanense, H. jiulianshanense and H. meilingense as three independent taxa within Helminthosporium. A list of accepted Helminthosporium species with major morphological features, host information, locality and sequence data was provided. This work expands our understanding of the diversity of Helminthosporium-like taxa in Jiangxi Province, China.

Usutu virus: An emerging flavivirus with potential threat to public health in Africa: Nigeria as a case study.

Usutu virus (USUV) is an arthropod-borne virus (arbovirus) of the flaviviridae family (genus Flavivirus) which belong to the Japanese encephalitis virus complex. Culex mosquitoes have been implicated in the transmission of this pathogen. The major susceptible hosts of USUV are migratory birds, thereby potentiating its ability to spread from one region to another globally. Nigeria has the largest economy in Africa with a significant percentage of the gross domestic product relying on the agricultural and animal production industry. This review explores the zoonotic potentials of the virus in Africa, especially Nigeria, with special focus on the devastating sequelae this might lead to in the future if necessary precautionary policies are not enacted and adopted to bolster the surveillance system for mosquito-borne viruses.

Differential Effects of Rhodococcus equi Virulence-Associated Proteins on Macrophages and Artificial Lipid Membranes.

Virulence-associated protein A (VapA) of Rhodococcus equi is a pathogenicity factor required for the multiplication of virulent R. equi strains within spacious macrophage vacuoles. The production of VapA is characteristic for R. equi isolates from pneumonic foals. VapB and VapN proteins in R. equi isolates from infected pig (VapB) and cattle (VapN) have amino acid sequences very similar to VapA and consequently have been assumed to be its functional correlates. Using model membrane experiments, phagosome pH acidification analysis, lysosome size measurements, protein partitioning, and degradation assays, we provide support for the view that VapA and VapN promote intracellular multiplication of R. equi by neutralizing the pH of the R. equi-containing vacuole. VapB does not neutralize vacuole pH, is not as membrane active as VapA, and does not support intracellular multiplication. This study also shows that the size of the sometimes enormous R. equi-containing vacuoles or the partitioning of purified Vaps into organic phases are not features that have predictive value for virulence of R. equi, whereas the ability of Vaps to increase phagosome pH is coupled to virulence. IMPORTANCE Rhodococcus equi is a major cause of life-threatening pneumonia in foals and occasionally in immunocompromised persons. Virulence-associated protein A (VapA) promotes R. equi multiplication in lung macrophages, which are the major host cells during foal infection. In this study, we compare cellular, biochemical, and biophysical phenotypes associated with VapA to those of VapB (typically produced by isolates from pigs) or VapN (isolates from cattle). Our data support the hypothesis that only some Vaps support multiplication in macrophages by pH neutralization of the phagosomes that R. equi inhabit.

Airborne bacterial community and antibiotic resistome in the swine farming environment: Metagenomic insights into livestock relevance, pathogen hosts and public risks

Globally extensive use of antibiotics has accelerated antimicrobial resistance (AMR) in the environment. As one of the biggest antibiotic consumers, livestock farms are hotspots in AMR prevalence, especially those in the atmosphere can transmit over long distances and pose inhalation risks to the public. Here, we collected total suspended particulates in swine farms and ambient air of an intensive swine farming area. Bacterial communities and antibiotic resistomes were analyzed using amplicon and metagenomic sequencing approaches. AMR risks and inhalation exposure to potential human-pathogenic antibiotic-resistant bacteria (HPARB) were subsequently estimated with comparison to the reported hospital samples. The results show that swine farms shaped the airborne bacterial community by increasing abundances, reducing diversities and shifting compositions. Swine feces contributed 77% of bacteria to swine farm air, and about 35% to ambient air. Airborne antibiotic resistomes in swine farms mainly conferred resistance to tetracyclines, aminoglycosides and lincosamides, and over 48% were originated from swine feces. Distinct to the hospital air, Firmicutes were dominant bacteria in swine farming environments with conditional pathogens including Clostridium, Streptococcus and Aerococcus being major hosts of antibiotic resistance genes (ARGs). Therein, genomes of S. alactolyticus carrying (transposase/recombinase-associated) ARGs and virulence factor genes were retrieved from the metagenomes of all swine feces and swine farm air samples, but they were not detected in any hospital air samples. This suggests the indication of S. alactolyticus in swine farming environments with potential hazards to human health. Swine farm air faced higher AMR risks than hospital air and swine feces. The inhalation intake of HPARB by a swine farm worker was about three orders of magnitude higher than a person who works in the hospital. Consequently, this study depicted atmospheric transmission of bacteria and antibiotic resistomes from swine feces to the environment.