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1.
Emerg Infect Dis ; 27(9): 2294-2300, 2021 09.
Article in English | MEDLINE | ID: mdl-34423760

ABSTRACT

Genomic analysis of a diverse collection of Clostridioides difficile ribotype 078 isolates from Ireland and 9 countries in Europe provided evidence for complex regional and international patterns of dissemination that are not restricted to humans. These isolates are associated with C. difficile colonization and clinical illness in humans and pigs.


Subject(s)
Clostridioides difficile , Clostridium Infections , Animals , Clostridioides , Clostridioides difficile/genetics , Clostridium Infections/epidemiology , Europe/epidemiology , Humans , Ribotyping , Swine
2.
J Clin Microbiol ; 59(6)2021 05 19.
Article in English | MEDLINE | ID: mdl-33782112

ABSTRACT

LamPORE is a novel diagnostic platform for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA combining loop-mediated isothermal amplification with nanopore sequencing, which could potentially be used to analyze thousands of samples per day on a single instrument. We evaluated the performance of LamPORE against reverse transcriptase PCR (RT-PCR) using RNA extracted from spiked respiratory samples and stored nose and throat swabs collected at two UK hospitals. The limit of detection of LamPORE was 10 genome copies/µl of extracted RNA, which is above the limit achievable by RT-PCR, but was not associated with a significant reduction of sensitivity in clinical samples. Positive clinical specimens came mostly from patients with acute symptomatic infection, and among them, LamPORE had a diagnostic sensitivity of 99.1% (226/228; 95% confidence interval [CI], 96.9% to 99.9%). Among negative clinical specimens, including 153 with other respiratory pathogens detected, LamPORE had a diagnostic specificity of 99.6% (278/279; 98.0% to 100.0%). Overall, 1.4% (7/514; 0.5% to 2.9%) of samples produced an indeterminate result on first testing, and repeat LamPORE testing on the same RNA extract had a reproducibility of 96.8% (478/494; 94.8% to 98.1%). LamPORE has a similar performance as RT-PCR for the diagnosis of SARS-CoV-2 infection in symptomatic patients and offers a promising approach to high-throughput testing.


Subject(s)
COVID-19 , Nanopore Sequencing , Humans , Molecular Diagnostic Techniques , Nucleic Acid Amplification Techniques , RNA, Viral/genetics , Reproducibility of Results , SARS-CoV-2 , Sensitivity and Specificity
3.
Article in English | MEDLINE | ID: mdl-32094139

ABSTRACT

Carbapenem resistance in Enterobacterales is a public health threat. Klebsiella pneumoniae carbapenemase (encoded by alleles of the blaKPC family) is one of the most common transmissible carbapenem resistance mechanisms worldwide. The dissemination of blaKPC historically has been associated with distinct K. pneumoniae lineages (clonal group 258 [CG258]), a particular plasmid family (pKpQIL), and a composite transposon (Tn4401). In the United Kingdom, blaKPC has represented a large-scale, persistent management challenge for some hospitals, particularly in North West England. The dissemination of blaKPC has evolved to be polyclonal and polyspecies, but the genetic mechanisms underpinning this evolution have not been elucidated in detail; this study used short-read whole-genome sequencing of 604 blaKPC-positive isolates (Illumina) and long-read assembly (PacBio)/polishing (Illumina) of 21 isolates for characterization. We observed the dissemination of blaKPC (predominantly blaKPC-2; 573/604 [95%] isolates) across eight species and more than 100 known sequence types. Although there was some variation at the transposon level (mostly Tn4401a, 584/604 [97%] isolates; predominantly with ATTGA-ATTGA target site duplications, 465/604 [77%] isolates), blaKPC spread appears to have been supported by highly fluid, modular exchange of larger genetic segments among plasmid populations dominated by IncFIB (580/604 isolates), IncFII (545/604 isolates), and IncR (252/604 isolates) replicons. The subset of reconstructed plasmid sequences (21 isolates, 77 plasmids) also highlighted modular exchange among non-blaKPC and blaKPC plasmids and the common presence of multiple replicons within blaKPC plasmid structures (>60%). The substantial genomic plasticity observed has important implications for our understanding of the epidemiology of transmissible carbapenem resistance in Enterobacterales for the implementation of adequate surveillance approaches and for control.


Subject(s)
Bacterial Proteins/genetics , Drug Resistance, Bacterial/genetics , Enterobacteriaceae/drug effects , Enterobacteriaceae/genetics , Molecular Epidemiology , Plasmids/genetics , beta-Lactamases/genetics , Anti-Bacterial Agents/pharmacology , Carbapenems/pharmacology , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Enterobacteriaceae Infections/epidemiology , Enterobacteriaceae Infections/genetics , Enterobacteriaceae Infections/microbiology , Genome, Bacterial , Humans , Klebsiella Infections/epidemiology , Retrospective Studies , United Kingdom/epidemiology , Whole Genome Sequencing
4.
Article in English | MEDLINE | ID: mdl-32205351

ABSTRACT

Resistance to amoxicillin-clavulanate, a widely used beta-lactam/beta-lactamase inhibitor combination antibiotic, is rising globally, and yet susceptibility testing remains challenging. To test whether whole-genome sequencing (WGS) could provide a more reliable assessment of susceptibility than traditional methods, we predicted resistance from WGS for 976 Escherichia coli bloodstream infection isolates from Oxfordshire, United Kingdom, comparing against phenotypes from the BD Phoenix (calibrated against EUCAST guidelines). A total of 339/976 (35%) isolates were amoxicillin-clavulanate resistant. Predictions based solely on beta-lactamase presence/absence performed poorly (sensitivity, 23% [78/339]) but improved when genetic features associated with penicillinase hyperproduction (e.g., promoter mutations and copy number estimates) were considered (sensitivity, 82% [277/339]; P < 0.0001). Most discrepancies occurred in isolates with MICs within ±1 doubling dilution of the breakpoint. We investigated two potential causes: the phenotypic reference and the binary resistant/susceptible classification. We performed reference standard, replicated phenotyping in a random stratified subsample of 261/976 (27%) isolates using agar dilution, following both EUCAST and CLSI guidelines, which use different clavulanate concentrations. As well as disagreeing with each other, neither agar dilution phenotype aligned perfectly with genetic features. A random-effects model investigating associations between genetic features and MICs showed that some genetic features had small, variable and additive effects, resulting in variable resistance classification. Using model fixed-effects to predict MICs for the non-agar dilution isolates, predicted MICs were in essential agreement (±1 doubling dilution) with observed (BD Phoenix) MICs for 691/715 (97%) isolates. This suggests amoxicillin-clavulanate resistance in E. coli is quantitative, rather than qualitative, explaining the poorly reproducible binary (resistant/susceptible) phenotypes and suboptimal concordance between different phenotypic methods and with WGS-based predictions.


Subject(s)
Amoxicillin-Potassium Clavulanate Combination , Escherichia coli , Amoxicillin-Potassium Clavulanate Combination/pharmacology , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Clavulanic Acid/pharmacology , Escherichia coli/genetics , Microbial Sensitivity Tests , Phenotype , United Kingdom , beta-Lactamases/genetics
5.
Article in English | MEDLINE | ID: mdl-30910889

ABSTRACT

Several emerging pathogens have arisen as a result of selection pressures exerted by modern health care. Klebsiella quasipneumoniae was recently defined as a new species, yet its prevalence, niche, and propensity to acquire antimicrobial resistance genes are not fully described. We have been tracking inter- and intraspecies transmission of the Klebsiella pneumoniae carbapenemase (KPC) gene, blaKPC, between bacteria isolated from a single institution. We applied a combination of Illumina and PacBio whole-genome sequencing to identify and compare K. quasipneumoniae from patients and the hospital environment over 10- and 5-year periods, respectively. There were 32 blaKPC-positive K. quasipneumoniae isolates, all of which were identified as K. pneumoniae in the clinical microbiology laboratory, from 8 patients and 11 sink drains, with evidence for seven separate blaKPC plasmid acquisitions. Analysis of a single subclade of K. quasipneumoniae subsp. quasipneumoniae (n = 23 isolates) from three patients and six rooms demonstrated seeding of a sink by a patient, subsequent persistence of the strain in the hospital environment, and then possible transmission to another patient. Longitudinal analysis of this strain demonstrated the acquisition of two unique blaKPC plasmids and then subsequent within-strain genetic rearrangement through transposition and homologous recombination. Our analysis highlights the apparent molecular propensity of K. quasipneumoniae to persist in the environment as well as acquire carbapenemase plasmids from other species and enabled an assessment of the genetic rearrangements which may facilitate horizontal transmission of carbapenemases.


Subject(s)
Klebsiella/enzymology , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Carbapenems/pharmacology , Drug Resistance, Multiple/genetics , Hospitals , Humans , Klebsiella/drug effects , Microbial Sensitivity Tests , Plasmids/genetics , beta-Lactamases/genetics , beta-Lactamases/metabolism
6.
J Clin Microbiol ; 58(1)2019 12 23.
Article in English | MEDLINE | ID: mdl-31666364

ABSTRACT

Influenza is a major global public health threat as a result of its highly pathogenic variants, large zoonotic reservoir, and pandemic potential. Metagenomic viral sequencing offers the potential for a diagnostic test for influenza virus which also provides insights on transmission, evolution, and drug resistance and simultaneously detects other viruses. We therefore set out to apply the Oxford Nanopore Technologies sequencing method to metagenomic sequencing of respiratory samples. We generated influenza virus reads down to a limit of detection of 102 to 103 genome copies/ml in pooled samples, observing a strong relationship between the viral titer and the proportion of influenza virus reads (P = 4.7 × 10-5). Applying our methods to clinical throat swabs, we generated influenza virus reads for 27/27 samples with mid-to-high viral titers (cycle threshold [CT ] values, <30) and 6/13 samples with low viral titers (CT values, 30 to 40). No false-positive reads were generated from 10 influenza virus-negative samples. Thus, Nanopore sequencing operated with 83% sensitivity (95% confidence interval [CI], 67 to 93%) and 100% specificity (95% CI, 69 to 100%) compared to the current diagnostic standard. Coverage of full-length virus was dependent on sample composition, being negatively influenced by increased host and bacterial reads. However, at high influenza virus titers, we were able to reconstruct >99% complete sequences for all eight gene segments. We also detected a human coronavirus coinfection in one clinical sample. While further optimization is required to improve sensitivity, this approach shows promise for the Nanopore platform to be used in the diagnosis and genetic analysis of influenza virus and other respiratory viruses.


Subject(s)
Influenza, Human/virology , Metagenomics , Nanopore Sequencing , Orthomyxoviridae/genetics , Computational Biology/methods , England/epidemiology , Genome, Viral , High-Throughput Nucleotide Sequencing , Humans , Influenza, Human/diagnosis , Influenza, Human/epidemiology , Metagenomics/methods , Nanopore Sequencing/methods , Orthomyxoviridae/classification , Phylogeny , RNA Viruses/classification , RNA Viruses/genetics , RNA, Viral
7.
Antimicrob Agents Chemother ; 60(6): 3767-78, 2016 06.
Article in English | MEDLINE | ID: mdl-27067320

ABSTRACT

The recent widespread emergence of carbapenem resistance in Enterobacteriaceae is a major public health concern, as carbapenems are a therapy of last resort against this family of common bacterial pathogens. Resistance genes can mobilize via various mechanisms, including conjugation and transposition; however, the importance of this mobility in short-term evolution, such as within nosocomial outbreaks, is unknown. Using a combination of short- and long-read whole-genome sequencing of 281 blaKPC-positive Enterobacteriaceae isolates from a single hospital over 5 years, we demonstrate rapid dissemination of this carbapenem resistance gene to multiple species, strains, and plasmids. Mobility of blaKPC occurs at multiple nested genetic levels, with transmission of blaKPC strains between individuals, frequent transfer of blaKPC plasmids between strains/species, and frequent transposition of blaKPC transposon Tn4401 between plasmids. We also identify a common insertion site for Tn4401 within various Tn2-like elements, suggesting that homologous recombination between Tn2-like elements has enhanced the spread of Tn4401 between different plasmid vectors. Furthermore, while short-read sequencing has known limitations for plasmid assembly, various studies have attempted to overcome this by the use of reference-based methods. We also demonstrate that, as a consequence of the genetic mobility observed in this study, plasmid structures can be extremely dynamic, and therefore these reference-based methods, as well as traditional partial typing methods, can produce very misleading conclusions. Overall, our findings demonstrate that nonclonal resistance gene dissemination can be extremely rapid, presenting significant challenges for public health surveillance and achieving effective control of antibiotic resistance.


Subject(s)
Enterobacteriaceae Infections/epidemiology , Enterobacteriaceae/genetics , Gene Transfer, Horizontal , beta-Lactam Resistance/genetics , beta-Lactamases/genetics , Anti-Bacterial Agents/pharmacology , Bacterial Typing Techniques , Carbapenems/pharmacology , Conjugation, Genetic , DNA Transposable Elements , Enterobacteriaceae/classification , Enterobacteriaceae/drug effects , Enterobacteriaceae/isolation & purification , Enterobacteriaceae Infections/drug therapy , Enterobacteriaceae Infections/microbiology , Gene Expression , High-Throughput Nucleotide Sequencing , Homologous Recombination , Humans , Phylogeny , Plasmids/chemistry , Plasmids/metabolism , Public Health Surveillance , Tertiary Care Centers , Virginia/epidemiology , beta-Lactamases/metabolism
8.
N Engl J Med ; 369(13): 1195-205, 2013 Sep 26.
Article in English | MEDLINE | ID: mdl-24066741

ABSTRACT

BACKGROUND: It has been thought that Clostridium difficile infection is transmitted predominantly within health care settings. However, endemic spread has hampered identification of precise sources of infection and the assessment of the efficacy of interventions. METHODS: From September 2007 through March 2011, we performed whole-genome sequencing on isolates obtained from all symptomatic patients with C. difficile infection identified in health care settings or in the community in Oxfordshire, United Kingdom. We compared single-nucleotide variants (SNVs) between the isolates, using C. difficile evolution rates estimated on the basis of the first and last samples obtained from each of 145 patients, with 0 to 2 SNVs expected between transmitted isolates obtained less than 124 days apart, on the basis of a 95% prediction interval. We then identified plausible epidemiologic links among genetically related cases from data on hospital admissions and community location. RESULTS: Of 1250 C. difficile cases that were evaluated, 1223 (98%) were successfully sequenced. In a comparison of 957 samples obtained from April 2008 through March 2011 with those obtained from September 2007 onward, a total of 333 isolates (35%) had no more than 2 SNVs from at least 1 earlier case, and 428 isolates (45%) had more than 10 SNVs from all previous cases. Reductions in incidence over time were similar in the two groups, a finding that suggests an effect of interventions targeting the transition from exposure to disease. Of the 333 patients with no more than 2 SNVs (consistent with transmission), 126 patients (38%) had close hospital contact with another patient, and 120 patients (36%) had no hospital or community contact with another patient. Distinct subtypes of infection continued to be identified throughout the study, which suggests a considerable reservoir of C. difficile. CONCLUSIONS: Over a 3-year period, 45% of C. difficile cases in Oxfordshire were genetically distinct from all previous cases. Genetically diverse sources, in addition to symptomatic patients, play a major part in C. difficile transmission. (Funded by the U.K. Clinical Research Collaboration Translational Infection Research Initiative and others.).


Subject(s)
Clostridioides difficile/genetics , Clostridium Infections/transmission , Cross Infection/transmission , Aged , Aged, 80 and over , Clostridioides difficile/isolation & purification , Clostridium Infections/epidemiology , Clostridium Infections/microbiology , Cross Infection/epidemiology , Cross Infection/microbiology , DNA, Bacterial/analysis , Disease Transmission, Infectious , Female , Genetic Variation , Genome-Wide Association Study , Humans , Incidence , Male , Sequence Analysis, DNA , United Kingdom
9.
J Clin Microbiol ; 54(5): 1388-90, 2016 05.
Article in English | MEDLINE | ID: mdl-26962081

ABSTRACT

Group B streptococcus (GBS) capsular serotypes are major determinants of virulence and affect potential vaccine coverage. Here we report a whole-genome-sequencing-based method for GBS serotype assignment. This method shows strong agreement (kappa of 0.92) with conventional methods and increased serotype assignment (100%) to all 10 capsular types.


Subject(s)
Bacterial Capsules/genetics , Molecular Typing/methods , Streptococcus agalactiae/classification , Streptococcus agalactiae/genetics , Genome, Bacterial , Humans , Sequence Analysis, DNA , Serotyping/methods
10.
J Dairy Sci ; 99(7): 5596-5603, 2016 Jul.
Article in English | MEDLINE | ID: mdl-27085413

ABSTRACT

Cross sucking by dairy calves occurs most commonly before weaning, but is of most concern in older animals where it has been claimed to cause mastitis and udder damage. Providing ad libitum milk allowance via a teat and gradual weaning reduces cross sucking, but low levels of this behavior still persist. Our aims were to understand why this behavior persists in some calves after weaning off milk and to examine whether individuals which are cross sucked postweaning are more likely to sustain teat injury or develop mastitis during their first lactation. Fifty-six female Holstein calves were housed in groups of 8 and fed milk, grain, and hay ad libitum from automated feeders. During weaning, milk allowance was gradually reduced according to grain intake. Cross sucking was recorded using overhead video cameras (5 observation periods of 72h). The effects of weaning on cross sucking were examined; to examine whether cross sucking affected udder health, all incidences of damaged quarters or clinical and sub-clinical mastitis in the first lactation were recorded, as was milk production. The overall level of cross sucking after weaning, at 4 to 5mo of age, was low and a small proportion of individuals accounted for the majority of events. The duration of cross sucking that occurred at 4 to 5mo of age was correlated with the amount of cross sucking done before and immediately after weaning. After weaning, the calves that cross sucked did so on certain calves, with the most sucked calf within each pen accounting for 73.98% of all cross-sucking events. No relationship was found between cross sucking and being cross sucked in the period before weaning but a positive correlation was found by 4 to 5mo of age. The majority of calves reduced or ceased cross sucking after weaning. Individuals still observed to be cross sucking by 4 to 5mo of age had formed pairs with other cross-sucking individuals and cross-sucking events occurred almost exclusively between these pairs. Cows that were cross sucked as heifers were no more likely to develop mastitis or have higher somatic cell count in their first lactation than those which were not involved in cross sucking. Cross sucking typically begins before weaning, but the formation of lasting pairs of reciprocal cross-sucking partners after weaning may be responsible for this behavior persisting in group housed dairy calves after weaning off milk. Low levels of cross sucking did not appear to have a negative effect on udder health.


Subject(s)
Milk , Weaning , Animals , Behavior, Animal , Cattle , Female , Housing, Animal , Mammary Glands, Animal
11.
J Dairy Sci ; 97(7): 4405-11, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24819136

ABSTRACT

A better understanding of when and where group-housed calves are most likely to defecate or urinate might permit improved housing design or more efficient use of cleaning routines. However, this is the first study to address the urination and defecation habits of calves. The primary aims of this study were to report the daily frequency of calves' urination and defecation and determine when and where group-housed dairy calves defecate and urinate most frequently. We were also interested to see if incidence of urination and defecation changed with increasing age and the change in diet at weaning. We observed 36 female Holstein calves, housed in groups of 9, and fed milk, grain, and hay from automated feeders. For the purposes of another experiment, these calves were assigned to 1 of 3 experimental treatments relating to age at start of weaning and milk allowance: low milk allowance and early weaning (6 L/d, 42 d), high milk allowance and early weaning (12 L/d, 42 d), and high milk allowance and late weaning (12 L/d, 84 d) The occurrence of defecations and urinations was determined by continuous observation of video recordings taken over 72 h at 2 age periods (age, mean ± SD; period 1=32.0 ± 11.13 d and period 2=61 ± 11.29 d). Due to the treatments, weaned and unweaned calves were observed in each period (period 1: 34 unweaned and 2 weaned calves; period 2: 16 unweaned and 20 weaned calves). Large differences were found between calves in mean daily frequency of total urinations and defecations across a 3-d period (mean=17.56 ± 5.07/d, range=4.33 to 28.67). Differences between individual calves did not change significantly over time, provided calves remained unweaned. Two days of observation was sufficient to give a reliable estimate of daily urination and defecation frequency. Frequency of urination and defecations was higher in calves postweaning. Higher age and visits to the milk feeder were associated with a higher frequency of urinations and defecations preweaning. After weaning, frequency of eliminations increased with increasing visits to the water feeder. An effect of time of day was observed, with significantly more events during daylight hours (0600-1800 h) in comparison to night (1800-0600 h). Before weaning, calves urinated and defecated significantly more on slatted flooring and sawdust-bedded areas than within the feeder (daily mean ± SD=6.96 ± 3.15, 6.49 ± 3.90, and 4.10 ± 2.67 for slatted floor, bedded floor, and feeder areas, respectively). Frequency of eliminations in feeders and slatted, but not sawdust-bedded, areas was higher in calves postweaning. Calves urinate and defecate more frequently during daylight hours when they are more active. Slatted flooring around feeders is useful to reduce soiling of bedded areas, particularly as calves increase in age.


Subject(s)
Behavior, Animal/physiology , Cattle/physiology , Housing, Animal , Milk/metabolism , Animals , Defecation , Female , Urination , Weaning
12.
J Infect Dis ; 207(4): 675-86, 2013 Feb 15.
Article in English | MEDLINE | ID: mdl-23204167

ABSTRACT

BACKGROUND: Clostridium difficile is a major cause of nosocomial diarrhea, with 30-day mortality reaching 30%. The cell surface comprises a paracrystalline proteinaceous S-layer encoded by the slpA gene within the cell wall protein (cwp) gene cluster. Our purpose was to understand the diversity and evolution of slpA and nearby genes also encoding immunodominant cell surface antigens. METHODS: Whole-genome sequences were determined for 57 C. difficile isolates representative of the population structure and different clinical phenotypes. Phylogenetic analyses were performed on their genomic region (>63 kb) spanning the cwp cluster. RESULTS: Genetic diversity across the cwp cluster peaked within slpA, cwp66 (adhesin), and secA2 (secretory translocase). These genes formed a 10-kb cassette, of which 12 divergent variants were found. Homologous recombination involving this cassette caused it to associate randomly with genotype. One cassette contained a novel insertion (length, approximately 24 kb) that resembled S-layer glycosylation gene clusters. CONCLUSIONS: Genetic exchange of S-layer cassettes parallels polysaccharide capsular switching in other species. Both cause major antigenic shifts, while the remainder of the genome is unchanged. C. difficile genotype is therefore not predictive of antigenic type. S-layer switching and immune escape could help explain temporal and geographic variation in C. difficile epidemiology and may inform genotyping and vaccination strategies.


Subject(s)
Bacterial Proteins/genetics , Clostridioides difficile/genetics , Genome, Bacterial , Recombination, Genetic , Sequence Analysis, DNA , Bacterial Proteins/metabolism , Clostridioides difficile/classification , Clostridioides difficile/isolation & purification , Clostridioides difficile/metabolism , Evolution, Molecular , Genetic Variation , Glycosylation , Humans , Molecular Sequence Data , Multigene Family , Phylogeny
13.
Animals (Basel) ; 14(2)2024 Jan 08.
Article in English | MEDLINE | ID: mdl-38254375

ABSTRACT

The commercial greyhound racing industry in New Zealand is struggling with an eroding social license and 'on-notice' status. Multiple independent reviews of the industry have identified ongoing issues of animal welfare during and between races, euthanasia decisions, poor data tracking, a lack of transparency and problems with rehoming dogs, resulting in New Zealand animal advocacy agencies and the general public questioning the continuation of greyhound racing. The current paper assessed the New Zealand public's awareness and familiarity with commercial greyhound racing, identified current levels of public support or opposition for racing, and provided context in terms of engagement with greyhound racing using a comprehensive survey of a robust sample of New Zealanders. The results confirm that the social license of the greyhound industry is under challenge with most respondents expressing disagreement with or lack of knowledge of current industry practices and indicating they would vote in support of a ban. There is scope for increasing public acceptability by addressing welfare issues, increasing awareness of positive industry practices, and encouraging transparency of the greyhound racing agency. However, as greyhound racing is on the decline worldwide, calls are likely to continue for a phase-out of commercial greyhound racing.

14.
Nat Commun ; 15(1): 1612, 2024 Feb 22.
Article in English | MEDLINE | ID: mdl-38383544

ABSTRACT

Plasmids carry genes conferring antimicrobial resistance and other clinically important traits, and contribute to the rapid dissemination of such genes. Previous studies using complete plasmid assemblies, which are essential for reliable inference, have been small and/or limited to plasmids carrying antimicrobial resistance genes (ARGs). In this study, we sequenced 1,880 complete plasmids from 738 isolates from bloodstream infections in Oxfordshire, UK. The bacteria had been originally isolated in 2009 (194 isolates) and 2018 (368 isolates), plus a stratified selection from intervening years (176 isolates). We demonstrate that plasmids are largely, but not entirely, constrained to a single host species, although there is substantial overlap between species of plasmid gene-repertoire. Most ARGs are carried by a relatively small number of plasmid groups with biological features that are predictable. Plasmids carrying ARGs (including those encoding carbapenemases) share a putative 'backbone' of core genes with those carrying no such genes. These findings suggest that future surveillance should, in addition to tracking plasmids currently associated with clinically important genes, focus on identifying and monitoring the dissemination of high-risk plasmid groups with the potential to rapidly acquire and disseminate these genes.


Subject(s)
Anti-Bacterial Agents , Bacteria , Plasmids/genetics , Bacteria/genetics
15.
Clin Infect Dis ; 56(11): 1589-600, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23463640

ABSTRACT

BACKGROUND: Despite substantial interest in biomarkers, their impact on clinical outcomes and variation with bacterial strain has rarely been explored using integrated databases. METHODS: From September 2006 to May 2011, strains isolated from Clostridium difficile toxin enzyme immunoassay (EIA)-positive fecal samples from Oxfordshire, United Kingdom (approximately 600,000 people) underwent multilocus sequence typing. Fourteen-day mortality and levels of 15 baseline biomarkers were compared between consecutive C. difficile infections (CDIs) from different clades/sequence types (STs) and EIA-negative controls using Cox and normal regression adjusted for demographic/clinical factors. RESULTS: Fourteen-day mortality was 13% in 2222 adults with 2745 EIA-positive samples (median, 78 years) vs 5% in 20,722 adults with 27,550 EIA-negative samples (median, 74 years) (absolute attributable mortality, 7.7%; 95% CI, 6.4%-9.0%). Mortality was highest in clade 5 CDIs (25% [16 of 63]; polymerase chain reaction (PCR) ribotype 078/ST 11), then clade 2 (20% [111 of 560]; 99% PCR ribotype 027/ST 1) versus clade 1 (12% [137 of 1168]; adjusted P < .0001). Within clade 1, 14-day mortality was only 4% (3 of 84) in ST 44 (PCR ribotype 015) (adjusted P = .05 vs other clade 1). Mean baseline neutrophil counts also varied significantly by genotype: 12.4, 11.6, and 9.5 × 10(9) neutrophils/L for clades 5, 2 and 1, respectively, vs 7.0 × 10(9) neutrophils/L in EIA-negative controls (P < .0001) and 7.9 × 10(9) neutrophils/L in ST 44 (P = .08). There were strong associations between C. difficile-type-specific effects on mortality and neutrophil/white cell counts (rho = 0.48), C-reactive-protein (rho = 0.43), eosinophil counts (rho = -0.45), and serum albumin (rho = -0.47). Biomarkers predicted 30%-40% of clade-specific mortality differences. CONCLUSIONS: C. difficile genotype predicts mortality, and excess mortality correlates with genotype-specific changes in biomarkers, strongly implicating inflammatory pathways as a major influence on poor outcome after CDI. PCR ribotype 078/ST 11 (clade 5) leads to severe CDI; thus ongoing surveillance remains essential.


Subject(s)
Clostridioides difficile/isolation & purification , Clostridium Infections/microbiology , Clostridium Infections/mortality , Aged , Aged, 80 and over , Biomarkers/analysis , Clostridioides difficile/classification , Clostridioides difficile/genetics , Clostridium Infections/epidemiology , Feces/microbiology , Female , Genotype , Humans , Immunoenzyme Techniques , Male , Middle Aged , Multilocus Sequence Typing , United Kingdom/epidemiology
16.
Clin Infect Dis ; 55 Suppl 2: S77-87, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22752869

ABSTRACT

Symptomatic recurrence of Clostridium difficile infection (CDI) occurs in approximately 20% of patients and is challenging to treat. Identifying those at high risk could allow targeted initial management and improve outcomes. Adult toxin enzyme immunoassay-positive CDI cases in a population of approximately 600,000 persons from September 2006 through December 2010 were combined with epidemiological/clinical data. The cumulative incidence of recurrence ≥ 14 days after the diagnosis and/or onset of first-ever CDI was estimated, treating death without recurrence as a competing risk, and predictors were identified from cause-specific proportional hazards regression models. A total of 1678 adults alive 14 days after their first CDI were included; median age was 77 years, and 1191 (78%) were inpatients. Of these, 363 (22%) experienced a recurrence ≥ 14 days after their first CDI, and 594 (35%) died without recurrence through March 2011. Recurrence risk was independently and significantly higher among patients admitted as emergencies, with previous gastrointestinal ward admission(s), last discharged 4-12 weeks before first diagnosis, and with CDI diagnosed at admission. Recurrence risk also increased with increasing age, previous total hours admitted, and C-reactive protein level at first CDI (all P < .05). The 4-month recurrence risk increased by approximately 5% (absolute) for every 1-point increase in a risk score based on these factors. Risk factors, including increasing age, initial disease severity, and hospital exposure, predict CDI recurrence and identify patients likely to benefit from enhanced initial CDI treatment.


Subject(s)
Clostridioides difficile/pathogenicity , Clostridium Infections/epidemiology , Clostridium Infections/prevention & control , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , C-Reactive Protein/analysis , Child , Clostridium Infections/diagnosis , Clostridium Infections/microbiology , Cross Infection/microbiology , Female , Follow-Up Studies , Hospitalization , Humans , Immunoenzyme Techniques/methods , Incidence , Male , Middle Aged , Predictive Value of Tests , Proportional Hazards Models , Risk Factors , Secondary Prevention , Severity of Illness Index , Time Factors , Treatment Outcome , Young Adult
17.
Biodivers Data J ; 10: e86089, 2022.
Article in English | MEDLINE | ID: mdl-36761559

ABSTRACT

Scientific collections have been built by people. For hundreds of years, people have collected, studied, identified, preserved, documented and curated collection specimens. Understanding who those people are is of interest to historians, but much more can be made of these data by other stakeholders once they have been linked to the people's identities and their biographies. Knowing who people are helps us attribute work correctly, validate data and understand the scientific contribution of people and institutions. We can evaluate the work they have done, the interests they have, the places they have worked and what they have created from the specimens they have collected. The problem is that all we know about most of the people associated with collections are their names written on specimens. Disambiguating these people is the challenge that this paper addresses. Disambiguation of people often proves difficult in isolation and can result in staff or researchers independently trying to determine the identity of specific individuals over and over again. By sharing biographical data and building an open, collectively maintained dataset with shared knowledge, expertise and resources, it is possible to collectively deduce the identities of individuals, aggregate biographical information for each person, reduce duplication of effort and share the information locally and globally. The authors of this paper aspire to disambiguate all person names efficiently and fully in all their variations across the entirety of the biological sciences, starting with collections. Towards that vision, this paper has three key aims: to improve the linking, validation, enhancement and valorisation of person-related information within and between collections, databases and publications; to suggest good practice for identifying people involved in biological collections; and to promote coordination amongst all stakeholders, including individuals, natural history collections, institutions, learned societies, government agencies and data aggregators.

18.
Commun Med (Lond) ; 2: 101, 2022.
Article in English | MEDLINE | ID: mdl-35968045

ABSTRACT

Background: Gram-negative organisms are common causes of bloodstream infection (BSI) during the neonatal period and early childhood. Whilst several large studies have characterised these isolates in adults, equivalent data (particularly incorporating whole genome sequencing) is lacking in the paediatric population. Methods: We perform an epidemiological and sequencing based analysis of Gram-negative bloodstream infections (327 isolates (296 successfully sequenced) from 287 patients) in children <18 years old between 2008 and 2018 in Oxfordshire, UK. Results: Here we show that the burden of infection lies predominantly in neonates and that most infections are caused by Escherichia coli, Klebsiella spp. and Enterobacter hormaechei. There is no evidence in our setting that the proportion of antimicrobial resistant isolates is increasing in the paediatric population although we identify some evidence of sub-breakpoint increases in gentamicin resistance. The population structure of E. coli BSI isolates in neonates and children mirrors that in adults with a predominance of STs 131/95/73/69 and the same proportions of O-antigen serotypes. In most cases in our setting there is no evidence of transmission/point-source acquisition and we demonstrate the utility of whole genome sequencing to refute a previously suspected outbreak. Conclusions: Our findings support continued use of current empirical treatment guidelines and suggest that O-antigen targeted vaccines may have a role in reducing the incidence of neonatal sepsis.

19.
J Clin Microbiol ; 49(11): 3994-6, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21940476

ABSTRACT

Molecular analysis of Clostridium difficile (28 isolates) from children (n = 128) in Oxfordshire, United Kingdom, identified eight toxigenic genotypes. Six of these were isolated from 27% of concurrent adult C. difficile-associated infections studied (n = 83). No children carried hypervirulent PCR ribotype 027. Children could participate in the transmission of some adult disease-causing genotypes.


Subject(s)
Clostridioides difficile/classification , Clostridioides difficile/isolation & purification , Clostridium Infections/epidemiology , Clostridium Infections/microbiology , Adolescent , Adult , Aged , Aged, 80 and over , Child, Preschool , Clostridioides difficile/genetics , DNA, Bacterial/genetics , Genotype , Humans , Infant , Middle Aged , Molecular Epidemiology , Ribotyping , United Kingdom/epidemiology , Young Adult
20.
Sci Rep ; 11(1): 19579, 2021 10 01.
Article in English | MEDLINE | ID: mdl-34599242

ABSTRACT

The increasing risk from viral outbreaks such as the ongoing COVID-19 pandemic exacerbates the need for rapid, affordable and sensitive methods for virus detection, identification and quantification; however, existing methods for detecting virus particles in biological samples usually depend on multistep protocols that take considerable time to yield a result. Here, we introduce a rapid fluorescence in situ hybridization (FISH) protocol capable of detecting influenza virus, avian infectious bronchitis virus and SARS-CoV-2 specifically and quantitatively in approximately 20 min, in virus cultures, combined nasal and throat swabs with added virus and likely patient samples without previous purification. This fast and facile workflow can be adapted both as a lab technique and a future diagnostic tool in enveloped viruses with an accessible genome.


Subject(s)
In Situ Hybridization, Fluorescence/methods , RNA, Viral/isolation & purification , Viruses/isolation & purification , Viruses/genetics
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