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Department of Veterinary Medicine

Cambridge Veterinary School
 

Exploring veterinary students' awareness and perception of zoonoses risks, infection control practices, and biosecurity measures in Ethiopia

Latest publications - Wed, 24/07/2024 - 11:00

Front Vet Sci. 2024 Jul 9;11:1385849. doi: 10.3389/fvets.2024.1385849. eCollection 2024.

ABSTRACT

Universities and colleges are often regarded as playing a key role in educating veterinarians and animal health workers who advise farmers on herd health and animal husbandry. However, to date, studies examining veterinary students' knowledge of zoonotic diseases of public health importance and the source of this knowledge, as well as their preparedness to respond to these diseases, have focused on the Global North rather than the Global South. This study takes Ethiopia as a case study in exploring veterinary medicine students' knowledge of zoonosis risks, infection control practices and biosecurity measures, recognizing that it is imperative to reconcile national-level veterinary education curricula with emerging global trends, such as One Health-focused training. This training advocates for a collaborative, interdisciplinary response at local, national, and international levels to the adverse impact of zoonotic diseases on animal health and productivity, and human and environmental health. Data for this study were collected through a pre-tested online questionnaire administered to 154 veterinary students from several universities in Ethiopia. The findings of this study suggest veterinary students were aware of the public health risks posed by zoonoses and the important role that collaboration between the disciplines of human and animal health can play in addressing zoonoses and emerging health risks. However, students demonstrated poor knowledge of the need to adopt infection control measures (ICPs) and biosecurity measures to reduce occupational risks and prevent within and between herd transmission of infection. Moreover, students' vaccination rates against zoonotic diseases associated with occupational risks, such as rabies, were low. The results of this study suggest that there are currently gaps in Ethiopia's veterinary curriculum and that enhancing veterinary students' access to information regarding infection control practices and biosecurity measures could contribute to reducing their future occupational exposure to zoonoses. This study highlights the policy implications of the current veterinary medicine curriculum in Ethiopia and the scope for aligning the curriculum with important global initiatives, such as One Health-focused training.

PMID:39044741 | PMC:PMC11263103 | DOI:10.3389/fvets.2024.1385849

A programmable and automated optical electrowetting-on-dielectric (oEWOD) driven platform for massively parallel and sequential processing of single cell assay operations

Latest publications - Mon, 22/07/2024 - 11:00

Lab Chip. 2024 Jul 22. doi: 10.1039/d4lc00245h. Online ahead of print.

ABSTRACT

Recently, there has been an increasing emphasis on single cell profiling for high-throughput screening workflows in drug discovery and life sciences research. However, the biology underpinning these screens is often complex and is insufficiently addressed by singleplex assay screens. Traditional single cell screening technologies have created powerful sets of 'omic data that allow users to bioinformatically infer biological function, but have as of yet not empowered direct functional analysis at the level of each individual cell. Consequently, screening campaigns often require multiple secondary screens leading to laborious, time-consuming and expensive workflows in which attrition points may not be queried until late in the process. We describe a platform that harnesses droplet microfluidics and optical electrowetting-on-dielectric (oEWOD) to perform highly-controlled sequential and multiplexed single cell assays in massively parallelised workflows to enable complex cell profiling during screening. Soluble reagents or objects, such as cells or assay beads, are encapsulated into droplets of media in fluorous oil and are actively filtered based on size and optical features ensuring only desirable droplets (e.g. single cell droplets) are retained for analysis, thereby overcoming the Poisson probability distribution. Droplets are stored in an array on a temperature-controlled chip and the history of individual droplets is logged from the point of filter until completion of the workflow. On chip, droplets are subject to an automated and flexible suite of operations including the merging of sample droplets and the fluorescent acquisition of assay readouts to enable complex sequential assay workflows. To demonstrate the broad utility of the platform, we present examples of single-cell functional workflows for various applications such as antibody discovery, infectious disease, and cell and gene therapy.

PMID:39037291 | DOI:10.1039/d4lc00245h

New genetic test will eliminate a form of inherited blindness in dogs

Departmental research news - Mon, 22/07/2024 - 00:38

Progressive retinal atrophy (PRA) is a group of inherited diseases that causes progressive degeneration of the light sensitive cells at the back of the eye. Dogs with PRA have normal sight at birth, but by the age of four or five they will be totally blind. There is no treatment.

Now a team led by the University of Cambridge has identified the genetic mutation that causes PRA in English Shepherd Dogs, and developed a DNA test for it. By identifying dogs carrying the disease before their eyesight starts to fail, this provides a tool to guide breeding decisions so the disease is not passed on to puppies.

Owners usually don’t realise their dog has PRA until it is middle-aged, by which time it might have bred, and passed on the faulty gene to its puppies. This has made it a difficult disease to control.

The new discovery means that progressive retinal atrophy can now be completely eliminated from the English Shepherd Dog population very quickly.

The results are published today in the journal Genes.

“Once the dog’s eyesight starts to fail there’s no treatment – it will end up totally blind,” said Katherine Stanbury, a researcher in the University of Cambridge’s Department of Veterinary Medicine and first author of the report.

She added: “Now we have a DNA test, there’s no reason why another English Shepherd Dog ever needs to be born with this form of progressive retinal atrophy – it gives breeders a way of totally eliminating the disease.”

The genetic mutation identified by the team is recessive, which means it only causes blindness if the English Shepherd Dog inherits two copies of it. If the dog only has one copy this makes it a carrier – it will not develop PRA but can pass the mutation on to its puppies. If two carriers are bred together, about one in four of the puppies will be affected with PRA.

Dogs breeds are very inbred, so many individuals are related – giving them a much higher chance of being affected by recessive diseases than humans.

The team began the research after being contacted by a distraught owner of an English Shepherd Dog that had been recently diagnosed with PRA. The dog had been working as a search and rescue dog but had to retire due to visual deterioration that has resulted in total blindness. The researchers put out a call for DNA samples from other owners or breeders of this breed, and received samples from six English Shepherds with PRA and twenty without it. This was enough for them to pinpoint the genetic mutation responsible for PRA using whole genome sequencing.

The team offers a commercial canine genetic testing service providing DNA tests to dog breeders to help them avoid breeding dogs that will develop inherited diseases. As part of this they will now offer a DNA test for Progressive Retinal Atrophy in English Shepherds. Anyone can buy a testing kit, costing just £48, to take a swab from inside their dog’s mouth and send it back for testing.

“An owner won't necessarily notice their dog has got anything wrong with its eyes until it starts bumping into the furniture. Unlike humans who will speak up if their sight isn’t right, dogs just have to get on with things,” said Dr Cathryn Mellersh in the University of Cambridge’s Department of Veterinary Medicine, senior author of the report.

She added: “For the price of a decent bag of dog food people can now have their English Shepherd tested for Progressive Retinal Atrophy prior to breeding. It’s about prevention, rather than a cure, and it means a huge amount to the people who breed these dogs. They no longer need to worry about whether the puppies are going to be healthy or are going to develop this horrible disease in a few years’ time.”

The English Shepherd is a breed of herding dog popular in the United States and is closely related to the Border Collie.

The new discovery is the thirty-third genetic mutation causing an inherited disease in dogs that the team has found – twenty-three of which cause eye diseases. They say that the health and wellbeing of many dogs has been compromised because of how they have been bred by humans.

PRA occurs in many dog breeds including the English Shepherd Dog. And it is similar to a disease called retinitis pigmentosa in humans, which also causes blindness. The researchers say that their work with dogs could shed light on the human version of the disease and potentially identify targets for gene therapy in the future.

The work was carried out in collaboration with Wisdom Panel, Mars Petcare, as part of the Consortium to Research Inherited Eye Diseases in Dogs (CRIEDD), with funding from the Dog’s Trust and the Kennel Club Charitable Trust.

Reference: Stanbury, K. et al, ‘Exonic SINE insertion in FAM161A is associated with autosomal recessive progressive retinal atrophy in the English Shepherd.’ July 2024.

Cambridge scientists have identified the genetic mutation that causes progressive retinal atrophy in English Shepherd Dogs, which results in incurable blindness, and developed a genetic test to help eliminate the disease from future generations of the breed.

Now we have a DNA test, there’s no reason why another English Shepherd Dog ever needs to be born with this form of progressive retinal atrophy – it gives breeders a way of totally eliminating the disease.Katherine StanburyEnglish Shepherd puppy


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Form and Function in the Digenea, with an Emphasis on Host-Parasite and Parasite-Bacteria Interactions

Latest publications - Mon, 15/07/2024 - 11:00

Adv Exp Med Biol. 2024;1454:3-45. doi: 10.1007/978-3-031-60121-7_1.

ABSTRACT

This review covers the general aspects of the anatomy and physiology of the major body systems in digenetic trematodes, with an emphasis on new knowledge of the area acquired since the publication of the second edition of this book in 2019. In addition to reporting on key recent advances in the morphology and physiology of tegumentary, sensory, neuromuscular, digestive, excretory, and reproductive systems, and their roles in host-parasite interactions, this edition includes a section discussing the known and putative roles of bacteria in digenean biology and physiology. Furthermore, a brief discussion of current trends in the development of novel treatment and control strategies based on a better understanding of the trematode body systems and associated bacteria is provided.

PMID:39008262 | DOI:10.1007/978-3-031-60121-7_1

Histological and Histopathological Features of the Third Metacarpal/Tarsal Parasagittal Groove and Proximal Phalanx Sagittal Groove in Thoroughbred Horses with Racing History

Latest publications - Sat, 13/07/2024 - 11:00

Animals (Basel). 2024 Jun 30;14(13):1942. doi: 10.3390/ani14131942.

ABSTRACT

Information regarding the histopathology of the proximal phalanx (P1) sagittal groove in racehorses is limited. Twenty-nine cadaver limbs from nine Thoroughbred racehorses in racing/race-training underwent histological examination. Histological specimens of the third metacarpal/metatarsal (MC3/MT3) parasagittal grooves and P1 sagittal grooves were graded for histopathological findings in hyaline cartilage (HC), calcified cartilage (CC), and subchondral plate and trabecular bone (SCB/TB) regions. Histopathological grades were compared between (1) fissure and non-fissure locations observed in a previous study and (2) dorsal, middle, and palmar/plantar aspects. (1) HC, CC, and SCB/TB grades were more severe in fissure than non-fissure locations in the MC3/MT3 parasagittal groove (p < 0.001). SCB/TB grades were more severe in fissure than non-fissure locations in the P1 sagittal groove (p < 0.001). (2) HC, CC, and SCB/TB grades including SCB collapse were more severe in the palmar/plantar than the middle aspect of the MC3/MT3 parasagittal groove (p < 0.001). SCB/TB grades including SCB collapse were more severe in the dorsal and middle than the palmar/plantar aspect of the P1 sagittal groove (p < 0.001). Histopathology in the SCB/TB region including bone fatigue injury was related to fissure locations, the palmar/plantar MC3/MT3 parasagittal groove, and the dorsal P1 sagittal groove.

PMID:38998057 | DOI:10.3390/ani14131942

Evolution of protective SARS-CoV-2-specific B and T cell responses upon vaccination and Omicron breakthrough infection

Latest publications - Mon, 08/07/2024 - 11:00

iScience. 2024 May 28;27(6):110138. doi: 10.1016/j.isci.2024.110138. eCollection 2024 Jun 21.

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron breakthrough infection (BTI) induced better protection than triple vaccination. To address the underlying immunological mechanisms, we studied antibody and T cell response dynamics during vaccination and after BTI. Each vaccination significantly increased peak neutralization titers with simultaneous increases in circulating spike-specific T cell frequencies. Neutralization titers significantly associated with a reduced hazard rate for SARS-CoV-2 infection. Yet, 97% of triple vaccinees became SARS-CoV-2 infected. BTI further boosted neutralization magnitude and breadth, broadened virus-specific T cell responses to non-vaccine-encoded antigens, and protected with an efficiency of 88% from further infections by December 2022. This effect was then assessed by utilizing mathematical modeling, which accounted for time-dependent infection risk, the antibody, and T cell concentration at any time point after BTI. Our findings suggest that cross-variant protective hybrid immunity induced by vaccination and BTI was an important contributor to the reduced virus transmission observed in Bavaria in late 2022 and thereafter.

PMID:38974469 | PMC:PMC11225850 | DOI:10.1016/j.isci.2024.110138

Genetic diversity, determinants, and dissemination of Burkholderia pseudomallei lineages implicated in melioidosis in Northeast Thailand

Latest publications - Sun, 07/07/2024 - 11:00

Nat Commun. 2024 Jul 7;15(1):5699. doi: 10.1038/s41467-024-50067-9.

ABSTRACT

Melioidosis is an often-fatal neglected tropical disease caused by an environmental bacterium Burkholderia pseudomallei. However, our understanding of the disease-causing bacterial lineages, their dissemination, and adaptive mechanisms remains limited. To address this, we conduct a comprehensive genomic analysis of 1,391 B. pseudomallei isolates collected from nine hospitals in northeast Thailand between 2015 and 2018, and contemporaneous isolates from neighbouring countries, representing the most densely sampled collection to date. Our study identifies three dominant lineages, each with unique gene sets potentially enhancing bacterial fitness in the environment. We find that recombination drives lineage-specific gene flow. Transcriptome analyses of representative clinical isolates from each dominant lineage reveal increased expression of lineage-specific genes under environmental conditions in two out of three lineages. This underscores the potential importance of environmental persistence for these dominant lineages. The study also highlights the influence of environmental factors such as terrain slope, altitude, and river direction on the geographical dispersal of B. pseudomallei. Collectively, our findings suggest that environmental persistence may play a role in facilitating the spread of B. pseudomallei, and as a prerequisite for exposure and infection, thereby providing useful insights for informing melioidosis prevention and control strategies.

PMID:38972886 | DOI:10.1038/s41467-024-50067-9

Evolution and host-specific adaptation of <em>Pseudomonas aeruginosa</em>

Latest publications - Thu, 04/07/2024 - 11:00

Science. 2024 Jul 5;385(6704):eadi0908. doi: 10.1126/science.adi0908. Epub 2024 Jul 5.

ABSTRACT

The major human bacterial pathogen Pseudomonas aeruginosa causes multidrug-resistant infections in people with underlying immunodeficiencies or structural lung diseases such as cystic fibrosis (CF). We show that a few environmental isolates, driven by horizontal gene acquisition, have become dominant epidemic clones that have sequentially emerged and spread through global transmission networks over the past 200 years. These clones demonstrate varying intrinsic propensities for infecting CF or non-CF individuals (linked to specific transcriptional changes enabling survival within macrophages); have undergone multiple rounds of convergent, host-specific adaptation; and have eventually lost their ability to transmit between different patient groups. Our findings thus explain the pathogenic evolution of P. aeruginosa and highlight the importance of global surveillance and cross-infection prevention in averting the emergence of future epidemic clones.

PMID:38963857 | DOI:10.1126/science.adi0908

Integrating functional metagenomics to decipher microbiome-immune interactions

Latest publications - Tue, 02/07/2024 - 11:00

Immunol Cell Biol. 2024 Jul 2. doi: 10.1111/imcb.12798. Online ahead of print.

ABSTRACT

Microbial metabolites can be viewed as the cytokines of the microbiome, transmitting information about the microbial and metabolic environment of the gut to orchestrate and modulate local and systemic immune responses. Still, many immunology studies focus solely on the taxonomy and community structure of the gut microbiota rather than its functions. Early sequencing-based microbiota profiling approaches relied on PCR amplification of small regions of bacterial and fungal genomes to facilitate identification of the microbes present. However, recent microbiome analysis methods, particularly shotgun metagenomic sequencing, now enable culture-independent profiling of microbiome functions and metabolites in addition to taxonomic characterization. In this review, we showcase recent advances in functional metagenomics methods and applications and discuss the current limitations and potential avenues for future development. Importantly, we highlight a few examples of key areas of opportunity in immunology research where integrating functional metagenomic analyses of the microbiome can substantially enhance a mechanistic understanding of microbiome-immune interactions and their contributions to health and disease states.

PMID:38952337 | DOI:10.1111/imcb.12798

VirBR, a transcription regulator, promotes IncX3 plasmid transmission, and persistence of bla<sub>NDM-5</sub> in zoonotic bacteria

Latest publications - Sat, 29/06/2024 - 11:00

Nat Commun. 2024 Jun 28;15(1):5498. doi: 10.1038/s41467-024-49800-1.

ABSTRACT

IncX3 plasmids carrying the New Delhi metallo-β-lactamase-encoding gene, blaNDM-5, are rapidly spreading globally in both humans and animals. Given that carbapenems are listed on the WHO AWaRe watch group and are prohibited for use in animals, the drivers for the successful dissemination of Carbapenem-Resistant Enterobacterales (CRE) carrying blaNDM-5-IncX3 plasmids still remain unknown. We observe that E. coli carrying blaNDM-5-IncX3 can persist in chicken intestines either under the administration of amoxicillin, one of the largest veterinary β-lactams used in livestock, or without any antibiotic pressure. We therefore characterise the blaNDM-5-IncX3 plasmid and identify a transcription regulator, VirBR, that binds to the promoter of the regulator gene actX enhancing the transcription of Type IV secretion systems (T4SS); thereby, promoting conjugation of IncX3 plasmids, increasing pili adhesion capacity and enhancing the colonisation of blaNDM-5-IncX3 transconjugants in animal digestive tracts. Our mechanistic and in-vivo studies identify VirBR as a major factor in the successful spread of blaNDM-5-IncX3 across one-health AMR sectors. Furthermore, VirBR enhances the plasmid conjugation and T4SS expression by the presence of copper and zinc ions, thereby having profound ramifications on the use of universal animal feeds.

PMID:38944647 | DOI:10.1038/s41467-024-49800-1

Characterization of mAbs against <em>Klebsiella pneumoniae</em> type 3 fimbriae isolated in a target-independent phage display campaign

Latest publications - Fri, 28/06/2024 - 11:00

Microbiol Spectr. 2024 Jun 28:e0040024. doi: 10.1128/spectrum.00400-24. Online ahead of print.

ABSTRACT

We used phage display, antibody engineering, and high-throughput assays to identify antibody-accessible targets of Klebsiella pneumoniae. We report the discovery of monoclonal antibodies (mAbs) binding to type 3 fimbrial proteins, including MrkA. We found that anti-MrkA mAbs were cross-reactive to a diverse panel of K. pneumoniae clinical isolates, representing different O-serotypes. mAbs binding to MrkA have previously been described and have been shown to provide prophylactic protection, although only modest protection when dosed therapeutically in vivo in a murine lung infection model. Here, we used a combination of binding and opsonophagocytic killing studies using a high-content imaging platform to provide a possible explanation for the modest therapeutic efficacy in vivo reported in that model. Our work shows that expression of K. pneumoniae type 3 fimbriae in in vitro culture is not homogenous within a bacterial population. Instead, sub-populations of bacteria that do, and do not, express type 3 fimbriae exist. In a high-content opsonophagocytic killing assay, we showed that MrkA-targeting antibodies initially promote killing by macrophages; however, over time, this effect is diminished. We hypothesize the reason for this is that bacteria not expressing MrkA can evade opsonophagocytosis. Our data support the fact that MrkA is a conserved, immunodominant protein that is antibody accessible on the surface of K. pneumoniae and suggest that additional studies should evaluate the potential of using anti-MrkA antibodies in different stages of K. pneumoniae infection (different sites in the body) as well as against K. pneumoniae biofilms in the body during infection and associated with medical devices.IMPORTANCEThere is an unmet, urgent need for the development of novel antimicrobial therapies for the treatment of Klebsiella pneumoniae infections. We describe the use of phage display, antibody engineering, and high-throughput assays to identify antibody-accessible targets of K. pneumoniae. We discovered monoclonal antibodies (mAbs) binding to the type 3 fimbrial protein MrkA. The anti-MrkA mAbs were found to be highly cross-reactive, binding to all K. pneumoniae strains tested from a diverse panel of clinical isolates, and were active in an opsonophagocytic killing assay at pM concentrations. MrkA is important for biofilm formation; thus, our data support further exploration of the use of anti-MrkA antibodies for preventing and/or controlling K. pneumoniae in biofilms and during infection.

PMID:38940542 | DOI:10.1128/spectrum.00400-24

Gut microbiota and immune profiling of microbiota-humanised versus wildtype mouse models of hepatointestinal schistosomiasis

Latest publications - Tue, 25/06/2024 - 11:00

Anim Microbiome. 2024 Jun 25;6(1):36. doi: 10.1186/s42523-024-00318-3.

ABSTRACT

Mounting evidence of the occurrence of direct and indirect interactions between the human blood fluke, Schistosoma mansoni, and the gut microbiota of rodent models raises questions on the potential role(s) of the latter in the pathophysiology of hepatointestinal schistosomiasis. However, substantial differences in both the composition and function between the gut microbiota of laboratory rodents and that of humans hinders an in-depth understanding of the significance of such interactions for human schistosomiasis. Taking advantage of the availability of a human microbiota-associated mouse model (HMA), we have previously highlighted differences in infection-associated changes in gut microbiota composition between HMA and wildtype (WT) mice. To further explore the dynamics of schistosome-microbiota relationships in HMA mice, in this study we (i) characterize qualitative and quantitative changes in gut microbiota composition of a distinct line of HMA mice (D2 HMA) infected with S. mansoni prior to and following the onset of parasite egg production; (ii) profile local and systemic immune responses against the parasite in HMA as well as WT mice and (iii) assess levels of faecal inflammatory markers and occult blood as indirect measures of gut tissue damage. We show that patent S. mansoni infection is associated with reduced bacterial alpha diversity in the gut of D2 HMA mice, alongside expansion of hydrogen sulphide-producing bacteria. Similar systemic humoral responses against S. mansoni in WT and D2 HMA mice, as well as levels of faecal lipocalin and markers of alternatively activated macrophages, suggest that these are independent of baseline gut microbiota composition. Qualitative comparative analyses between faecal microbial profiles of S. mansoni-infected WT and distinct lines of HMA mice reveal that, while infection-induced alterations of the gut microbiota composition are highly dependent on the baseline flora, bile acid composition and metabolism may represent key elements of schistosome-microbiota interactions through the gut-liver axis.

PMID:38918824 | DOI:10.1186/s42523-024-00318-3

Deep sequencing of Escherichia coli exposes colonisation diversity and impact of antibiotics in Punjab, Pakistan

Latest publications - Tue, 18/06/2024 - 11:00

Nat Commun. 2024 Jun 18;15(1):5196. doi: 10.1038/s41467-024-49591-5.

ABSTRACT

Multi-drug resistant (MDR) E. coli constitute a major public health burden globally, reaching the highest prevalence in the global south yet frequently flowing with travellers to other regions. However, our comprehension of the entire genetic diversity of E. coli colonising local populations remains limited. We quantified this diversity, its associated antimicrobial resistance (AMR), and assessed the impact of antibiotic use by recruiting 494 outpatients and 423 community dwellers in the Punjab province, Pakistan. Rectal swab and stool samples were cultured on CLED agar and DNA extracted from plate sweeps was sequenced en masse to capture both the genetic and AMR diversity of E. coli. We assembled 5,247 E. coli genomes from 1,411 samples, displaying marked genetic diversity in gut colonisation. Compared with high income countries, the Punjabi population generally showed a markedly different distribution of genetic lineages and AMR determinants, while use of antibiotics elevated the prevalence of well-known globally circulating MDR clinical strains. These findings implicate that longitudinal multi-regional genomics-based surveillance of both colonisation and infections is a prerequisite for developing mechanistic understanding of the interplay between ecology and evolution in the maintenance and dissemination of (MDR) E. coli.

PMID:38890378 | DOI:10.1038/s41467-024-49591-5

The delayed kinetics of Myddosome formation explains why amyloid-beta aggregates trigger Toll-like receptor 4 less efficiently than lipopolysaccharide

Latest publications - Wed, 12/06/2024 - 11:00

Elife. 2024 Jun 12;13:RP92350. doi: 10.7554/eLife.92350.

ABSTRACT

The Myddosome is a key innate immune signalling platform. It forms at the cell surface and contains MyD88 and IRAK proteins which ultimately coordinate the production of pro-inflammatory cytokines. Toll-like receptor 4 (TLR4) signals via the Myddosome when triggered by lipopolysaccharide (LPS) or amyloid-beta (Aβ) aggregates but the magnitude and time duration of the response are very different for reasons that are unclear. Here, we followed the formation of Myddosomes in live macrophages using local delivery of TLR4 agonist to the cell surface and visualisation with 3D rapid light sheet imaging. This was complemented by super-resolution imaging of Myddosomes in fixed macrophages to determine the size of the signalling complex at different times after triggering. Myddosomes formed more rapidly after LPS than in response to sonicated Aβ 1-42 fibrils (80 vs 372 s). The mean lifetimes of the Myddosomes were also shorter when triggered by LPS compared to sonicated Aβ fibrils (170 and 220 s), respectively. In both cases, a range of Myddosome of different sizes (50-500 nm) were formed. In particular, small round Myddosomes around 100 nm in size formed at early time points, then reduced in proportion over time. Collectively, our data suggest that compared to LPS the multivalency of Aβ fibrils leads to the formation of larger Myddosomes which form more slowly and, due to their size, take longer to disassemble. This explains why sonicated Aβ fibrils results in less efficient triggering of TLR4 signalling and may be a general property of protein aggregates.

PMID:38864842 | DOI:10.7554/eLife.92350

Microarray analysis demonstrates upregulation of the endothelin-1 gene with compensatory downregulation of the ETA receptor gene in human portal vein

Latest publications - Tue, 11/06/2024 - 11:00

Biosci Rep. 2024 Jun 11:BSR20240528. doi: 10.1042/BSR20240528. Online ahead of print.

ABSTRACT

High blood pressure in the portal vein, portal hypertension (PH), is the final common pathway in liver cirrhosis regardless of aetiology. Complications from PH are the major cause of morbidity and mortality in these patients. Current drug therapy to reduce portal pressure is mainly limited to β-adrenergic receptor blockade but about forty percent of patients do not respond. Our aim was to use microarray to measure the expression of ~20,800 genes in portal vein from patients with PH undergoing transplantation for liver cirrhosis (PH, n = 12) versus healthy vessels (control, n = 9) to identify potential drug targets to improve therapy. Expression of 9,964 genes above background was detected in portal vein samples. Comparing PH veins versus control (adjusted p value < 0.05, fold change > 1.5) identified 548 upregulated genes and 1,996 downregulated genes. The 2,544 differentially expressed genes were subjected to pathway analysis. We identified 49 significantly enriched pathways. The endothelin pathway was ranked the tenth most significant, the only vasoconstrictive pathway to be identified. ET-1 gene (EDN1) was significantly upregulated, consistent with elevated levels of ET-1 peptide previously measured in PH and cirrhosis. ETA receptor gene (EDNRA) was significantly downregulated, consistent with an adaptive response to increased peptide levels in the portal vein but there was no change in the ETB gene (EDNRB). The results provide further support for evaluating the efficacy of ETA receptor antagonists as a potential therapy in addition to β-blockers in patients with PH and cirrhosis.

PMID:38860875 | DOI:10.1042/BSR20240528

Global surveillance of emerging SARS-CoV-2 variants

Latest publications - Mon, 03/06/2024 - 11:00

Bull World Health Organ. 2024 Jun 1;102(6):374-374A. doi: 10.2471/BLT.22.289528.

NO ABSTRACT

PMID:38828061 | PMC:PMC11132165 | DOI:10.2471/BLT.22.289528

Expression of the apelin receptor, a novel potential therapeutic target, and its endogenous ligands in diverse stem cell populations in human glioblastoma

Latest publications - Tue, 28/05/2024 - 11:00

Front Neurosci. 2024 May 13;18:1379658. doi: 10.3389/fnins.2024.1379658. eCollection 2024.

ABSTRACT

Glioblastoma multiforme (GBM) is one of the most common and lethal forms of brain cancer, carrying a very poor prognosis (median survival of ~15 months post-diagnosis). Treatment typically involves invasive surgical resection of the tumour mass, followed by radiotherapy and adjuvant chemotherapy using the alkylating agent temozolomide, but over half of patients do not respond to this drug and considerable resistance is observed. Tumour heterogeneity is the main cause of therapeutic failure, where diverse progenitor glioblastoma stem cell (GSC) lineages in the microenvironment drive tumour recurrence and therapeutic resistance. The apelin receptor is a class A GPCR that binds two endogenous peptide ligands, apelin and ELA, and plays a role in the proliferation and survival of cancer cells. Here, we used quantitative whole slide immunofluorescent imaging of human GBM samples to characterise expression of the apelin receptor and both its ligands in the distinct GSC lineages, namely neural-progenitor-like cells (NPCs), oligodendrocyte-progenitor-like cells (OPCs), and mesenchymal-like cells (MES), as well as reactive astrocytic cells. The data confirm the presence of the apelin receptor as a tractable drug target that is common across the key cell populations driving tumour growth and maintenance, offering a potential novel therapeutic approach for patients with GBM.

PMID:38803685 | PMC:PMC11128631 | DOI:10.3389/fnins.2024.1379658

Modelling control strategies for pneumococcal meningitis outbreaks in the African meningitis belt

Latest publications - Sun, 26/05/2024 - 11:00

Vaccine. 2024 May 25:S0264-410X(24)00590-5. doi: 10.1016/j.vaccine.2024.05.031. Online ahead of print.

ABSTRACT

INTRODUCTION: Pneumococcal meningitis outbreaks occur sporadically in the African meningitis belt. Outbreak control guidelines and interventions are well established for meningococcal but not pneumococcal meningitis. Mathematical modelling is a useful tool for assessing the potential impact of different pneumococcal control strategies. This work aimed to estimate the impact of reactive vaccination with pneumococcal conjugate vaccine (PCV) had it been implemented in past African meningitis belt outbreaks and assess their efficiency relative to existing routine infant immunisation with PCV.

METHODS & RESULTS: Using recent pneumococcal meningitis outbreaks in Burkina Faso, Chad, and Ghana as case studies, we investigated the potential impact of reactive vaccination. We calculated the number needed to vaccinate to avert one case (NNV) in each outbreak setting and over all outbreaks and compared this to the NNV for existing routine infant vaccination. We extended previous analyses of reactive vaccination by considering longer-term protection in vaccinees over five years, incorporating a proxy for indirect effects. We found that implementing reactive vaccination in previous pneumococcal meningitis outbreaks could have averted up to 10-20 % of outbreak cases, with the biggest potential impact in Brong Ahafo, Ghana (2015-2016) and Goundi, Chad (2009). The NNV, and hence the value of reactive vaccination, varied greatly. 'Large' (80 + cumulative modelled cases per 100,000 population) and/or 'prolonged' (exceeding a response threshold of 10 suspected cases per 100,000 per week for four weeks or more) outbreaks had NNV estimates under 10,000. For routine infant vaccination with PCV, the estimated NNV ranged from 3,100-5,600 in Burkina Faso and 1,500-2,600 in Ghana.

IMPLICATIONS: This analysis provides evidence to inform the design of pneumococcal meningitis outbreak response guidelines. Countries should consider reactive vaccination in each outbreak event, together with maintaining routine infant vaccination as the primary intervention to reduce pneumococcal disease burden and outbreak risk.

PMID:38797628 | DOI:10.1016/j.vaccine.2024.05.031

Evaluating the Efficacy of a Peripheral Nerve Simulator-Guided Brachial Plexus Block in Rabbits Undergoing Orthopaedic Surgery Compared to Systemic Analgesia

Latest publications - Fri, 24/05/2024 - 11:00

Vet Sci. 2024 May 13;11(5):213. doi: 10.3390/vetsci11050213.

ABSTRACT

Locoregional anaesthetic techniques are invaluable for providing multimodal analgesia for painful surgical procedures. This prospective, randomised study describes a nerve stimulator-guided brachial plexus blockade (BPB) in rabbits undergoing orthopaedic surgery in comparison to systemic lidocaine. Premedication was provided with intramuscular (IM) medetomidine, fentanyl, and midazolam. Anaesthesia was induced (propofol IV) and maintained with isoflurane. Nine rabbits received a lidocaine BPB (2%; 0.3 mL kg-1), and eight received a lidocaine constant rate infusion (CRI) (2 mg kg-1 IV, followed by 100 µg kg-1 min-1). Rescue analgesia was provided with fentanyl IV. Carprofen was administered at the end of the surgery. Postoperative pain was determined using the Rabbit Grimace Scale (RGS) and a composite pain scale. Buprenorphine was administered according to the pain score for two hours after extubation. Rabbits were filmed during the first two hours to measure distance travelled and behaviours. Food intake and faeces output were compared. Every rabbit in CRI required intraoperative rescue analgesia compared to none in BPB. However, rabbits in both groups had similar pain scores, and there was no difference in the administration of postoperative analgesia. There were no significant differences in food intake or faeces production over 18 h, and no significant differences in distance travelled or behaviours examined during the first two hours. BPB seems superior for intraoperative analgesia. Postoperatively, both groups were comparable.

PMID:38787185 | DOI:10.3390/vetsci11050213

Ectoparasite and bacterial population genetics and community structure indicate extent of bat movement across an island chain

Latest publications - Fri, 24/05/2024 - 11:00

Parasitology. 2024 May 24:1-53. doi: 10.1017/S0031182024000660. Online ahead of print.

NO ABSTRACT

PMID:38785194 | DOI:10.1017/S0031182024000660