Publications by authors named "Gally D"

This study supports the development of predictive bacteriophage (phage) therapy: the concept of phage cocktail selection to treat a bacterial infection based on machine learning (ML) models. For this purpose, ML models were trained on thousands of measured interactions between a panel of phage and sequenced bacterial isolates. The concept was applied to associated with urinary tract infections.

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The aim of this study was to compare Illumina and Oxford Nanopore Technology (ONT) sequencing data to quantify genetic variation to assess within-outbreak strain relatedness and characterise microevolutionary events in the accessory genomes of a cluster of 23 genetically and epidemiologically linked isolates related to an outbreak of Shiga toxin-producing Escherichia coli O157:H7 caused by the consumption of raw drinking milk. There were seven discrepant variants called between the two technologies, five were false-negative or false-positive variants in the Illumina data and two were false-negative calls in ONT data. After masking horizontally acquired sequences such as prophages, analysis of both short and long-read sequences revealed the 20 isolates linked to the outbreak in 2017 had a maximum SNP distance of one SNP between each other, and a maximum of five SNPs when including three additional strains identified in 2019.

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O26 is the commonest non-O157 Shiga toxin ()-producing serogroup reported in human infections worldwide. Ruminants, particularly cattle, are the primary reservoir source for human infection. In this study, we compared the whole genomes and virulence profiles of O26:H11 strains ( = 99) isolated from Scottish cattle with strains from human infections ( = 96) held by the Scottish O157/STEC Reference Laboratory, isolated between 2002 and 2020.

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is a taxonomically diverse pathogen with over 2600 serovars associated with a wide variety of animal hosts including humans, other mammals, birds and reptiles. Some serovars are host-specific or host-restricted and cause disease in distinct host species, while others, such as serovar . Typhimurium (STm), are generalists and have the potential to colonize a wide variety of species.

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Article Synopsis
  • Shiga toxin-producing E. coli (STEC) infections from wildlife are on the rise, with a notable instance in Scotland linked to venison in 2015 revealing gaps in knowledge about these pathogens.
  • A nationwide survey in Scotland found a low prevalence of STEC O157 in wild deer at 0.28%, but the bacteria were still found in high quantities in their feces and showed strong potential to cause human illness.
  • A follow-up investigation suggested that one particular wild deer sample may have contributed to a human outbreak in 2017, underscoring the need for strict food safety measures when handling venison.
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  • Over the past 20 years, the frequency of human infections caused by the E. coli strain O157 has been 2.5 times higher in Scotland compared to England and Wales.
  • A study combining cattle survey data and human clinical cases from 2014-2015 found that certain strains of O157 are more prevalent in Scottish cattle and humans, particularly the Stx2a+ strain PT21/28.
  • Whole genome sequencing revealed that most O157 diversity in human cases stemmed from cattle, with significant strain differences indicating localized transmission within Scotland.
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Antimicrobial resistance is a major threat to human and animal health. There is an urgent need to ensure that antimicrobials are used appropriately to limit the emergence and impact of resistance. In the human and veterinary healthcare setting, traditional culture and antimicrobial sensitivity testing typically requires 48-72 h to identify appropriate antibiotics for treatment.

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Introduction: Extended spectrum beta-lactamase (ESBL) producing have become widespread among food producing animals. These strains serve as a reservoir of antibiotic resistance genes (ARGs) and act as a possible source of infection to humans as transmission can occur by direct or indirect contact.

Methods: This study investigated the faecal carriage of ESBL producing and colistin resistant in poultry over a 2-year period (2017-2019) from Zimbabwe.

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Nationwide, wastewater-based monitoring was newly established in Scotland to track the levels of SARS-CoV-2 viral RNA shed into the sewage network, during the COVID-19 pandemic. We present a curated, reference dataset produced by this national programme, from May 2020 to February 2022. Viral levels were analysed by RT-qPCR assays of the N1 gene, on RNA extracted from wastewater sampled at 162 locations.

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Article Synopsis
  • The study focuses on the emergence of a specific lineage of Shiga toxin-producing E. coli (STEC) O157:H7, known as lineage IIc, responsible for foodborne illnesses in England, and analyzes its domestic and non-domestic reservoirs along with patient exposures.
  • Researchers conducted a genomic epidemiological analysis on 925 STEC O157:H7 samples from patients in England between June 2015 and December 2020, utilizing whole-genome sequencing and various data sources to map transmission dynamics.
  • Findings revealed the presence of two domestic and four non-domestic clades of lineage IIc, with non-domestic transmissions being more prevalent; patients with domestic infections had significant exposure to fresh produce and livestock, indicating potential
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Objectives: This study investigated antimicrobial susceptibility and genomic profiling of isolated from bloodstream infections at a tertiary referral hospital in Lusaka, Zambia, 2018-2019.

Method: This was a prospective hospital-based study involving routine blood culture samples submitted to the microbiology laboratory at the University Teaching Hospital. Identification of and determination of antimicrobial susceptibility profiles was achieved through conventional and automated methods.

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This study was designed to characterize extended-spectrum beta-lactamase (ESBL)-producing extra-intestinal pathogenic Escherichia coli (E.coli) (ExPEC) associated with urinary tract infections in nine different geographic regions of Zimbabwe over a 2-year period (2017-2019). A total of 48 ESBL-positive isolates from urine specimen were selected for whole-genome sequencing from 1246 Escherichia coli isolates biobanked at the National Microbiology Reference laboratory using phenotypic susceptibility testing results from the National Escherichia coli Surveillance Programme to provide representation of different geographical regions and year of isolation.

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The human zoonotic pathogen O157:H7 is defined by its extensive prophage repertoire including those that encode Shiga toxin, the factor responsible for inducing life-threatening pathology in humans. As well as introducing genes that can contribute to the virulence of a strain, prophage can enable the generation of large-chromosomal rearrangements (LCRs) by homologous recombination. This work examines the types and frequencies of LCRs across the major lineages of the O157:H7 serotype.

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Wastewater based epidemiology (WBE) has become an important tool during the COVID-19 pandemic, however the relationship between SARS-CoV-2 RNA in wastewater treatment plant influent (WWTP) and cases in the community is not well-defined. We report here the development of a national WBE program across 28 WWTPs serving 50% of the population of Scotland, including large conurbations, as well as low-density rural and remote island communities. For each WWTP catchment area, we quantified spatial and temporal relationships between SARS-CoV-2 RNA in wastewater and COVID-19 cases.

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Cattle are the main reservoir of Enterohemorrhagic Escherichia coli (EHEC), with O157:H7 the distinctive serotype. EHEC is the main causative agent of a severe systemic disease, Hemolytic Uremic Syndrome (HUS). Argentina has the highest pediatric HUS incidence worldwide with 12-14 cases per 100,000 children.

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(EPEC) and (EHEC) are considered emerging zoonotic pathogens of worldwide distribution. The pathogenicity of the bacteria is conferred by multiple virulence determinants, including the locus of enterocyte effacement (LEE) pathogenicity island, which encodes a type III secretion system (T3SS) and effector proteins, including the multifunctional secreted effector protein (EspF). EspF sequences differ between EPEC and EHEC serotypes in terms of the number and residues of SH3-binding polyproline-rich repeats and N-terminal localization sequence.

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Background: The porcine gastrointestinal microbiota has been linked to both host health and performance. Most pig gut microbiota studies target faecal material, which is not representative of microbiota dynamics in other discrete gut sections. The weaning transition period in pigs is a key development stage, with gastrointestinal problems being prominent after often sudden introduction to a solid diet.

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is an obligate intracellular bacterium associated with enteric disease in pigs. Clinical signs include weight loss, diarrhea, and, in some cases, sudden death. The hallmark lesion is the thickening of the intestinal mucosa caused by increased epithelial cell replication, known as proliferative enteropathy.

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Article Synopsis
  • Cattle in Scotland serve as a reservoir for Shiga toxin-producing (STEC) pathogens, contributing to higher rates of STEC infections among humans compared to the European average.
  • A study collected and analyzed fecal samples from 110 herds, revealing varying herd-level prevalence rates for non-O157 serogroups O26, O103, O111, and O145, with O26 being the most common.
  • Seasonal and regional differences were noted, with higher prevalence of certain serogroups in the South West during autumn, and a lack of positive herds associated with Central Scotland and winter.
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Escherichia coli is a species of bacteria that can be present in a wide variety of mammalian hosts and potentially soil environments. E. coli has an open genome and can show considerable diversity in gene content between isolates.

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Host adaptation of pathogens may increase intra- and interspecies transmission. We showed previously that the passage of a clinically isolated enterohemorrhagic Escherichia coli (EHEC) O157 strain (125/99) through the gastrointestinal tract of mice increases its pathogenicity in the same host. In this work, we aimed to elucidate the underlying mechanism(s) involved in the patho-adaptation of the stool-recovered (125RR) strain.

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Bacterial flagella have many established roles beyond swimming motility. Despite clear evidence of flagella-dependent adherence, the specificity of the ligands and mechanisms of binding are still debated. In this study, the molecular basis of O157:H7 and serovar Typhimurium flagella binding to epithelial cell cultures was investigated.

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Shiga-toxigenic Escherichia coli (STEC) is often transmitted into food via fresh produce plants, where it can cause disease. To identify early interaction factors for STEC on spinach, a high-throughput positive-selection system was used. A bacterial artificial chromosome (BAC) clone library for isolate Sakai was screened in four successive rounds of short-term (2 h) interaction with spinach roots, and enriched loci identified by microarray.

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A high-throughput positive-selection approach was taken to generate a dataset of Shigatoxigenic (STEC) O157:H7 genes enriched in adherence to plant tissue. The approach generates a differential dataset based on BAC clones enriched in the output, after adherence, compared to the inoculum used as the input. A BAC clone library derived from STEC isolate 'Sakai' was used since this isolate is associated with a very large-scale outbreak of human disease from consumption of contaminated fresh produce; white radish sprouts.

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Inflammation is critical for infection control and acts as an arsenal defense mechanism against invading microbes through activation of the host immune system. It works via its inflammasome components to sense the dangerous invading microorganism and send messages to the immune system to destroy them. To date, the function of bovine macrophage inflammasome and its relationship with actin has not been identified.

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