The application of CRISPR‐Cas for single species identification from environmental DNA

We report the first application of CRISPR‐Cas technology to single species detection from environmental DNA (eDNA). Organisms shed and excrete DNA into their environment such as in skin cells and faeces, referred to as environmental DNA (eDNA). Utilising eDNA allows noninvasive monitoring with increased specificity and sensitivity. Current methods primarily employ PCR‐based techniques to detect a given species from eDNA samples, posing a logistical challenge for on‐site monitoring and potential adaptation to biosensor devices. We have developed an alternative method; coupling isothermal amplification to a CRISPR‐Cas12a detection system. This utilises the collateral cleavage activity of Cas12a, a ribonuclease guided by a highly specific single CRISPR RNA. We used the target species Salmo salar as a proof‐of‐concept test of the specificity of the assay among closely related species and to show the assay is successful at a single temperature of 37°C with signal detection at 535 nM. The specific assay, detects at attomolar sensitivity with rapid detection rates (<2.5 hr). This approach simplifies the challenge of building a biosensor device for rapid target species detection in the field and can be easily adapted to detect any species from eDNA samples from a variety of sources enhancing the capabilities of eDNA as a tool for monitoring biodiversity.     

Integrating population genetics to define conservation units from the core to the edge of Rhinolophus ferrumequinum western range

The greater horseshoe bat (Rhinolophus ferrumequinum) is among the most widespread bat species in Europe but it has experienced severe declines, especially in Northern Europe. This species is listed Near Threatened in the European IUCN Red List of Threatened Animals, and it is considered to be highly sensitive to human activities and particularly to habitat fragmentation. Therefore, understanding the population boundaries and demographic history of populations of this species is of primary importance to assess relevant conservation strategies. In this study, we used 17 microsatellite markers to assess the genetic diversity, the genetic structure, and the demographic history of R. ferrumequinum colonies in the western part of its distribution. We identified one large population showing high levels of genetic diversity and large population size. Lower estimates were found in England and northern France. Analyses of clustering and isolation by distance suggested that the Channel and the Mediterranean seas could impede R. ferrumequinum gene flow. These results provide important information to improve the delineation of R. ferrumequinum management units. We suggest that a large management unit corresponding to the population ranging from Spanish Basque Country to northern France must be considered. Particular attention should be given to mating territories as they seem to play a key role in maintaining high levels of genetic mixing between colonies. Smaller management units corresponding to English and northern France colonies must also be implemented. These insular or peripheral colonies could be at higher risk of extinction in the near future.     

Impact of assessment and intervention by a health and social care professional team in the emergency department on the quality,safety, and clinical effectiveness of care for older adults: A randomised controlled trial

BackgroundOlder adults frequently attend the emergency department (ED) and experience high rates of adverse events following ED presentation. This randomised controlled trial evaluated the impact of early assessment and intervention by a dedicated team of health and social care professionals (HSCPs) in the ED on the quality, safety, and clinical effectiveness of care of older adults in the ED.Methods and findingsThis single-site randomised controlled trial included a sample of 353 patients aged ≥65 years (mean age = 79.6, SD = 7.01; 59.2% female) who presented with lower urgency complaints to the ED a university hospital in the Mid-West region of Ireland, during HSCP operational hours. The intervention consisted of early assessment and intervention carried out by a HSCP team comprising a senior medical social worker, senior occupational therapist, and senior physiotherapist. The primary outcome was ED length of stay. Secondary outcomes included rates of hospital admissions from the ED; hospital length of stay for admitted patients; patient satisfaction with index visit; ED revisits, mortality, nursing home admission, and unscheduled hospital admission at 30-day and 6-month follow-up; and patient functional status and quality of life (at index visit and follow-up). Demographic information included the patient’s gender, age, marital status, residential status, mode of arrival to the ED, source of referral, index complaint, triage category, falls, and hospitalisation history. Participants in the intervention group (n = 176) experienced a significantly shorter ED stay than the control group (n = 177) (6.4 versus 12.1 median hours, p < 0.001). Other significant differences (intervention versus control) included lower rates of hospital admissions from the ED (19.3% versus 55.9%, p < 0.001), higher levels of satisfaction with the ED visit (p = 0.008), better function at 30-day (p = 0.01) and 6-month follow-up (p = 0.03), better mobility (p = 0.02 at 30 days), and better self-care (p = 0.03 at 30 days; p = 0.009 at 6 months). No differences at follow-up were observed in terms of ED re-presentation or hospital admission. Study limitations include the inability to blind patients or ED staff to allocation due to the nature of the intervention, and a focus on early assessment and intervention in the ED rather than care integration following discharge.ConclusionsEarly assessment and intervention by a dedicated ED-based HSCP team reduced ED length of stay and the risk of hospital admissions among older adults, as well as improving patient satisfaction. Our findings support the effectiveness of an interdisciplinary model of care for key ED outcomes.Trial registrationClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT03739515","term_id":"NCT03739515"}}NCT03739515; registered on 12 November 2018.

Marica Cassarino and colleagues evaluate an intervention for early assessment of older patients in emergency care.     

An exported kinase (FIKK4.2) that mediates virulence-associated changes in Plasmodium falciparum-infected red blood cells

Alteration of the adhesive and mechanical properties of red blood cells caused by infection with the malaria parasite Plasmodium falciparum underpin both its survival and extreme pathogenicity. A unique family of parasite putative exported kinases, collectively called FIKK (Phenylalanine (F) – Isoleucine (I) – Lysine (K) – Lysine (K)), has recently been implicated in these pathophysiological processes, however, their precise function in P. falciparum-infected red blood cells or their likely role in malaria pathogenesis remain unknown. Here, for the first time, we demonstrate that one member of the FIKK family, FIKK4.2, can function as an active kinase and is localised in a novel and distinct compartment of the parasite-infected red blood cell which we have called K-dots. Notably, targeted disruption of the gene encoding FIKK4.2 (fikk4.2) dramatically alters the parasite’s ability to modify and remodel the red blood cells in which it multiplies. Specifically, red blood cells infected with fikk4.2 knockout parasites were significantly less rigid and less adhesive when compared with red blood cells infected with normal parasites from which the transgenic clones had been derived, despite expressing similar levels of the major cytoadhesion ligand, PfEMP1, on the red blood cell surface. Notably, these changes were accompanied by dramatically altered knob-structures on infected red blood cells that play a key role in cytoadhesion which is responsible for much of the pathogenesis associated with falciparum malaria. Taken together, our data identifies FIKK4.2 as an important kinase in the pathogenesis of P. falciparum malaria and strengthens the attractiveness of FIKK kinases as targets for the development of novel next-generation anti-malaria drugs.     

FKBP12.6 Activates RyR1: Investigating the Amino Acid Residues Critical for Channel Modulation

We have previously shown that FKBP12 associates with RyR2 in cardiac muscle and that it modulates RyR2 function differently to FKBP12.6. We now investigate how these proteins affect the single-channel behavior of RyR1 derived from rabbit skeletal muscle. Our results show that FKBP12.6 activates and FKBP12 inhibits RyR1. It is likely that both proteins compete for the same binding sites on RyR1 because channels that are preactivated by FKBP12.6 cannot be subsequently inhibited by FKBP12. We produced a mutant FKBP12 molecule (FKBP12_{E31Q/D32N/W59F}) where the residues Glu³¹, Asp³², and Trp⁵⁹ were converted to the corresponding residues in FKBP12.6. With respect to the functional regulation of RyR1 and RyR2, the FKBP12_{E31Q/D32N/W59F} mutant lost all ability to behave like FKBP12 and instead behaved like FKBP12.6. FKBP12_{E31Q/D32N/W59F} activated RyR1 but was not capable of activating RyR2. In conclusion, FKBP12.6 activates RyR1, whereas FKBP12 activates RyR2 and this selective activator phenotype is determined within the amino acid residues Glu³¹, Asp³², and Trp⁵⁹ in FKBP12 and Gln³¹, Asn³², and Phe⁵⁹ in FKBP12.6. The opposing but different effects of FKBP12 and FKBP12.6 on RyR1 and RyR2 channel gating provide scope for diversity of regulation in different tissues.     

FKBP12.6 Activates RyR1: Investigating the Amino Acid Residues Critical for Channel Modulation

We have previously shown that FKBP12 associates with RyR2 in cardiac muscle and that it modulates RyR2 function differently to FKBP12.6. We now investigate how these proteins affect the single-channel behavior of RyR1 derived from rabbit skeletal muscle. Our results show that FKBP12.6 activates and FKBP12 inhibits RyR1. It is likely that both proteins compete for the same binding sites on RyR1 because channels that are preactivated by FKBP12.6 cannot be subsequently inhibited by FKBP12. We produced a mutant FKBP12 molecule (FKBP12_{E31Q/D32N/W59F}) where the residues Glu³¹, Asp³², and Trp⁵⁹ were converted to the corresponding residues in FKBP12.6. With respect to the functional regulation of RyR1 and RyR2, the FKBP12_{E31Q/D32N/W59F} mutant lost all ability to behave like FKBP12 and instead behaved like FKBP12.6. FKBP12_{E31Q/D32N/W59F} activated RyR1 but was not capable of activating RyR2. In conclusion, FKBP12.6 activates RyR1, whereas FKBP12 activates RyR2 and this selective activator phenotype is determined within the amino acid residues Glu³¹, Asp³², and Trp⁵⁹ in FKBP12 and Gln³¹, Asn³², and Phe⁵⁹ in FKBP12.6. The opposing but different effects of FKBP12 and FKBP12.6 on RyR1 and RyR2 channel gating provide scope for diversity of regulation in different tissues.