Autophagy-linked plasma and lysosomal membrane protein PLAC8 is a key host factor for SARS-CoV-2 entry into human cells.

Better understanding on interactions between SARS-CoV-2 and host cells should help to identify host factors that may be targetable to combat infection and COVID-19 pathology. To this end, we have conducted a genome-wide CRISPR/Cas9-based loss-of-function screen in human lung cancer cells infected with SARS-CoV-2-pseudotyped lentiviruses. Our results recapitulate many findings from previous screens that used full SARS-CoV-2 viruses, but also unveil two novel critical host factors: the lysosomal efflux transporter SPNS1 and the plasma and lysosomal membrane protein PLAC8. Functional experiments with full SARS-CoV-2 viruses confirm that loss-of-function of these genes impairs viral entry. We find that PLAC8 is a key limiting host factor, whose overexpression boosts viral infection in eight different human lung cancer cell lines. Using single-cell RNA-Seq data analyses, we demonstrate that PLAC8 is highly expressed in ciliated and secretory cells of the respiratory tract, as well as in gut enterocytes, cell types that are highly susceptible to SARS-CoV-2 infection. Proteomics and cell biology studies suggest that PLAC8 and SPNS1 regulate the autophagolysosomal compartment and affect the intracellular fate of endocytosed virions.

A field test of the dilution effect hypothesis in four avian multi-host pathogens.

The Dilution Effect Hypothesis (DEH) argues that greater biodiversity lowers the risk of disease and reduces the rates of pathogen transmission since more diverse communities harbour fewer competent hosts for any given pathogen, thereby reducing host exposure to the pathogen. DEH is expected to operate most intensely in vector-borne pathogens and when species-rich communities are not associated with increased host density. Overall, dilution will occur if greater species diversity leads to a lower contact rate between infected vectors and susceptible hosts, and between infected hosts and susceptible vectors. Field-based tests simultaneously analysing the prevalence of several multi-host pathogens in relation to host and vector diversity are required to validate DEH. We tested the relationship between the prevalence in house sparrows (Passer domesticus) of four vector-borne pathogens-three avian haemosporidians (including the avian malaria parasite Plasmodium and the malaria-like parasites Haemoproteus and Leucocytozoon) and West Nile virus (WNV)-and vertebrate diversity. Birds were sampled at 45 localities in SW Spain for which extensive data on vector (mosquitoes) and vertebrate communities exist. Vertebrate censuses were conducted to quantify avian and mammal density, species richness and evenness. Contrary to the predictions of DEH, WNV seroprevalence and haemosporidian prevalence were not negatively associated with either vertebrate species richness or evenness. Indeed, the opposite pattern was found, with positive relationships between avian species richness and WNV seroprevalence, and Leucocytozoon prevalence being detected. When vector (mosquito) richness and evenness were incorporated into the models, all the previous associations between WNV prevalence and the vertebrate community variables remained unchanged. No significant association was found for Plasmodium prevalence and vertebrate community variables in any of the models tested. Despite the studied system having several characteristics that should favour the dilution effect (i.e., vector-borne pathogens, an area where vector and host densities are unrelated, and where host richness is not associated with an increase in host density), none of the relationships between host species diversity and species richness, and pathogen prevalence supported DEH and, in fact, amplification was found for three of the four pathogens tested. Consequently, the range of pathogens and communities studied needs to be broadened if we are to understand the ecological factors that favour dilution and how often these conditions occur in nature.

Retrospective Identification of Early Autochthonous Case of Crimean-Congo Hemorrhagic Fever, Spain, 2013.

Before this report, 7 autochthonous human cases of Crimean-Congo hemorrhagic fever had been reported in Spain, all occurring since 2016. We describe the retrospective identification of an eighth case dating back to 2013. This study highlights that the earliest cases of an emerging disease are often difficult to recognize.

"There is something you must see": breaking down the remission concept in rheumatoid arthritis from a rheumatologist's perspective.

OBJECTIVES: To explore the remission concept in rheumatoid arthritis (RA) and the implications of the existing definitions when applied to clinical practice among rheumatologists with different profiles. METHODS: A qualitative study through focus groups was conducted. Three focus groups were organised from February to March 2016. Each group was composed of rheumatologists with extensive clinical experience with different profiles; experts in basic research (RBR), experts in imaging techniques research (RIR), and experts in clinical research (RCR). The data was collected with audio recording. Verbatim transcriptions of the audio files were made, and a subsequent reflexive thematic analysis assisted by ATLAS.ti (GmbH, Berlin, v. 7) software was performed. RESULTS: From the reflexive thematic analysis, three main themes were generated: (1) remission limitations, (2) instruments or measures to assess remission, and (3) a new definition of remission. Rheumatologists mentioned frequently that the following variables should be considered when developing a new remission definition: inflammatory activity, calprotectin, psychological variables, sex, disease stage, and sociocultural factors. Contrary to what could be expected, all groups acknowledged that their research field could contribute with domains for a gold standard remission instrument, but not in a hierarchical arrangement of importance. The dissonance existing in the entire remission evaluation process was outlined: remission in clinical practice versus remission in clinical trials, remission following the American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) Boolean versus Musculoskeletal Ultrasound (US) remission, and remission from the rheumatologist's point of view versus the patient's point of view. CONCLUSIONS: Currently, rheumatologists would not accept a domain as more important than others in remission. Our suggestion is, not to generate a universal definition of remission - one that could cover all aspects - but rather to develop definitions of remission for the different settings that could be pondered by the patient's perspective.

Experimental infection of grey partridges with Bagaza virus: pathogenicity evaluation and potential role as a competent host.

Bagaza virus (BAGV; synonymous to Israel turkey meningoencephalomyelitis virus, ITV) is a relevant arthropod-borne epornitic flavivirus. In its first emergence in Europe (southern Spain, 2010) BAGV caused an outbreak, severely affecting red-legged partridges and common pheasants. The effects (pathogenicity, role as reservoir host) of BAGV in other European phasianids are unknown. To fill this gap, grey partridges were experimentally infected with BAGV. The clinical course of the disease was severe, with neurological signs, significant weight loss and 40% mortality. Low viral loads in the blood and the absence of contact transmission suggest a limited-if any-role on BAGV transmission for this European phasianid.

Pathogenicity evaluation of twelve West Nile virus strains belonging to four lineages from five continents in a mouse model: discrimination between three pathogenicity categories.

Rodent models have been used extensively to study West Nile virus (WNV) infection because they develop severe neurological symptoms similar to those observed in human WNV neuroinvasive disease. Most of this research has focused on old lineage (L) 1 strains, while information about pathogenicity is lacking for the most recent L1 and L2 strains, as well as for newly defined lineages. In this study, 4-week-old Swiss mice were inoculated with a collection of 12 WNV isolates, comprising 10 old and recent L1 and L2 strains, the putative L6 strain from Malaysia and the proposed L7 strain Koutango (KOU). The intraperitoneal inoculation of 10-fold dilutions of each strain allowed the characterization of the isolates in terms of LD50, median survival times, ID50, replication in neural and extraneural tissues and antibody production. Based on these results, we classified the isolates in three groups: high virulence (all L1a strains, recent L2 strains and KOU), moderate virulence (B956 strain) and low virulence (Kunjin and Malaysian isolates). We determined that the inoculation of a single dose of 1000 p.f.u. would be sufficient to classify WNV strains by pathotype. We confirmed the enhanced virulence of the KOU strain with a high capacity to cause rapid systemic infection. We also corroborated that differences in pathogenicity among strains do not correlate with phylogenetic lineage or geographic origin, and confirmed that recent European and African WNV strains belonging to L1 and L2 are highly virulent and do not differ in their pathotype profile compared to the prototype NY99 strain.

Exploring the remission concept in rheumatoid arthritis with patients and rheumatologists: time for a new approach?

OBJECTIVES: To explore the remission concept in rheumatoid arthritis (RA) and to compare remission definitions and related concepts between rheumatologists and patients with the purpose of identifying similarities and disparities to comprehend the different perspectives of the disease. METHODS: This was a qualitative study of discourse and content analysis through focus groups, conducted from February to March 2016. Four focus groups were set up, each one with different interests: rheumatologists involved in basic research (BR), rheumatologists with high specialisation in imaging techniques (IR), clinical rheumatologists (CR), and patients (PA). RESULTS: There is no consensus in a remission definition in RA; differences exist between-groups, rheumatologists and patients value remission differently, and there are discrepancies within the group of rheumatologists. Rheumatologists highlight quantifiable objective parameters, in contrast, patients did not consider objective measures as the best instruments, and they prefer subjective measures of remission. The data confirmed the existence of two sources of knowledge of the disease, technical (physicians) and experiential (patients). These sources of knowledge should concur in order to establish new remission criteria well-adjusted to reality. CONCLUSIONS: The lack of consensus between key groups implicated in defining remission and remission criteria suggests a new strategy for its operational definition. Our group proposes that subjects with a balance between experiential and technical knowledge, should be the ones in charge of this assignment.

Readmissions due to acute biliary edematous pancreatitis in patients without cholecystectomy.

AIMS: Analyzing the readmission of patients with acute biliary edematous pancreatitis (ABEP) without cholecystectomy despite a previous episode of mild acute gallstone pancreatitis or lithiasic cholecystitis. Calculating the health costs associated with the non-performance of cholecystectomy. MATERIAL AND METHODS: Prospective observational study conducted at a tertiary hospital from July to November 2014. The study has consecutively included inpatients suffering from ABEP who: a) had suffered a previous episode of mild acute gallstone pancreatitis or cholecystitis at least 2 weeks before readmission; and b) had not undergone cholecystectomy despite the lack of contraindications. RESULTS: During the research period, 9 patients (7 females and 2 males) with a mean age of 65.3 years (standard deviation [SD] 19.2) were readmitted. The median number of days between the previous episode of ABEP or cholecystitis and the readmission was 114 days (interquartile range [IQR] 111.0). Reported median overall length of hospital stay was 10 days (IQR = 2.0). Patients underwent a mean of 2.8 (SD = 1.2) ultrasound scans, 1.3 (SD = 0.9) abdominal and pelvic CT, 0.8 (SD = 1.0) MRCP and 0.2 (SD = 0.4) ERCP. The mean cost per patient for each readmission, including hospital stay (143.0 €/day), Emergency Service (332.31 €) and tests performed was 2,381.70 €/patient. CONCLUSIONS: Not performing a cholecystectomy within two weeks after a first episode of mild ABEP or cholecystitis contributes to patient readmission due to recurrent pancreatitis, resulting in avoidable treatment costs.

Bagaza virus is pathogenic and transmitted by direct contact in experimentally infected partridges, but is not infectious in house sparrows and adult mice.

Bagaza virus (BAGV) is a mosquito-borne flavivirus belonging to the Ntaya serocomplex. In 2010, a disease outbreak was reported in Cádiz (Southern Spain) affecting game birds (red-legged partridges and common pheasants). In this work, red-legged partridges were inoculated experimentally with infectious BAGV isolated from this outbreak in order to make a complete clinical and analytical assessment of the disease caused by the pathogen in this species. Viral load (by real-time RT-PCR) in blood, oral and cloacal swabs, and feathers, and neutralizing antibody titres (by VNT) were measured. In order to determine direct contact transmission, non-inoculated partridges were caged together with the inoculated ones. To assess infectiousness in other species, house sparrows and mice were also inoculated with the virus. All the inoculated partridges were clinically affected, and 30% of them died. All the infected individuals lost weight, with larger losses being recorded in females. Conversely, no mortality or disease symptoms were observed in the sparrows or mice. Remarkably, all the contact partridges acquired the infection by direct (non-vectored) transmission. This study confirms that the red-legged partridge is a susceptible host for BAGV infection, and that this pathogen is transmitted by direct contact. Long-lasting viral loads detected in calami of immature feathers demonstrate that feather sampling could be a useful strategy in active surveillance programs for early detection of BAGV.

Experimental infection of house sparrows (Passer domesticus) with West Nile virus isolates of Euro-Mediterranean and North American origins.

West Nile virus (WNV) is a zoonotic arboviral pathogen transmitted by mosquitoes in a cycle involving wild birds as reservoir hosts. The virus has recently emerged in North America and re-emerged in Europe. North American WNV outbreaks are often accompanied by high mortality in wild birds, a feature that is uncommon in Europe. The reason for this difference is unknown, but the intrinsic virulence of the viruses circulating in each continent and/or the susceptibility to the disease of Palearctic as opposed to Nearctic wild bird species could play a role. To assess this question, experimental inoculations with four lineage 1 WNV strains, three from southern Europe (Italy/2008, Italy/2009 and Spain/2007) and one from North America (NY99) were performed on house sparrows (Passer domesticus), a wild passerine common in both continents. Non-significant differences which ranged from 0% to 25% were observed in mortality for the different WNV strains. Viremias lasted from 1 to 5-6 days post-inoculation (dpi) in all cases; individuals inoculated with NY99 had significantly higher titres than those inoculated with any of the Euro-Mediterranean strains. Remarkably, host competence was found to be higher for NY99 than for the other strains. Consequently, albeit being pathogenic for house sparrows, some Euro-Mediterranean strains had reduced capacity for replication in -and transmission from- this host, as compared to the NY99 strain. If applicable also to other wild bird host species, this relatively reduced transmission capacity of the Euro-Mediterranean strains could explain the lower incidence of this disease in wild birds in the Euro-Mediterranean area.