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1.
Microbiol Resour Announc ; 13(1): e0079223, 2024 Jan 17.
Article in English | MEDLINE | ID: mdl-38099682

ABSTRACT

The whole-genome sequence of Escherichia coli strain DP033 is reported here. DP033 was isolated from a human rectal specimen in Tilburg, the Netherlands. In silico analysis showed that DP033 possessed 36 virulence-related genes and is a presumptive extraintestinal pathogenic E. coli and uropathogenic E. coli strain.

2.
EBioMedicine ; 99: 104909, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38096689

ABSTRACT

BACKGROUND: Escherichia coli sequence type 131 (ST131), specifically its fluoroquinolone-resistant H30R clade (ST131-H30R), is a global multidrug-resistant pathogen. The gut microbiome's role in ST131-H30R intestinal carriage is undefined. METHODS: Veterans and their household members underwent longitudinal fecal swab surveillance for ST131 in 2014-2018. The fecal microbiome was characterized by 16S rRNA qPCR and sequencing. We evaluated associations between ST131-H30R carriage and gut microbiome at baseline by random forest models to identify the most informative gut bacterial phyla and genera attributes for ST131 and ST131-H30R carriage status. Next, we assessed longitudinal associations between fecal microbiome and ST131-H30R carriage using a mixed-effects logistic regression with longitudinal measures. FINDINGS: Of the 519 participants, 78 were carriers of ST131, among whom 49 had ST131-H30R. At the baseline timepoint, H30R-positive participants had higher proportional abundances of Actinobacteria phylum (mean: 4.9% vs. 3.1%) than ST131-negative participants. H30R-positive participants also had higher abundances of Collinsella (mean: 2.3% vs. 1.1%) and lower abundances of Alistipes (mean: 2.1% vs. 2.6%) than ST131-negative participants. In the longitudinal analysis, Collinsella abundance correlated positively with ST131-H30R carriage status and negatively with the loss of ST131-H30R. Conversely, Alistipes corresponded with the loss and persistent absence of ST131-H30R even in the presence of a household exposure. INTERPRETATION: Abundances of specific fecal bacteria correlated with ST131-H30R carriage, persistence, and loss, suggesting their potential as targets for microbiome-based strategies to reduce carriage of ST131-H30R, a significant risk factor for invasive infections. FUNDING: This work was supported in part by National Institute of Allergy and Infectious Diseases of the National Institutes of Health under award numbers R21AI117654 and UM1AI104681 and the Office of Research and Development, Department of Veterans Affairs. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or the Department of Veterans Affairs.


Subject(s)
Escherichia coli Infections , Escherichia coli Proteins , Gastrointestinal Microbiome , Humans , Escherichia coli , Escherichia coli Infections/microbiology , Gastrointestinal Microbiome/genetics , RNA, Ribosomal, 16S/genetics , Escherichia coli Proteins/genetics , beta-Lactamases/genetics , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Drug Resistance, Multiple, Bacterial
3.
One Health ; 16: 100518, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37363239

ABSTRACT

A one-health perspective may provide new and actionable information about Escherichia coli transmission. E. coli colonizes a broad range of vertebrates, including humans and food-production animals, and is a leading cause of bladder, kidney, and bloodstream infections in humans. Substantial evidence supports foodborne transmission of pathogenic E. coli strains from food animals to humans. However, the relative contribution of foodborne zoonotic E. coli (FZEC) to the human extraintestinal disease burden and the distinguishing characteristics of such strains remain undefined. Using a comparative genomic analysis of a large collection of contemporaneous, geographically-matched clinical and meat-source E. coli isolates (n = 3111), we identified 17 source-associated mobile genetic elements - predominantly plasmids and bacteriophages - and integrated them into a novel Bayesian latent class model to predict the origins of clinical E. coli isolates. We estimated that approximately 8 % of human extraintestinal E. coli infections (mostly urinary tract infections) in our study population were caused by FZEC. FZEC strains were equally likely to cause symptomatic disease as non-FZEC strains. Two FZEC lineages, ST131-H22 and ST58, appeared to have particularly high virulence potential. Our findings imply that FZEC strains collectively cause more urinary tract infections than does any single non-E. coli uropathogenic species (e.g., Klebsiella pneumoniae). Our novel approach can be applied in other settings to identify the highest-risk FZEC strains, determine their sources, and inform new one-health strategies to decrease the heavy public health burden imposed by extraintestinal E. coli infections.

4.
MicroPubl Biol ; 20232023.
Article in English | MEDLINE | ID: mdl-37090152

ABSTRACT

Changes in neuronal function that occur with age are an area of increasing importance. A potential significant contributor to age-dependent decline may be alterations to neurotransmitter release. Protein kinases, such as Protein Kinase C and Protein Kinase A, are well characterised modulators of neuronal function and neurotransmission. Protein Kinase D (PRKD) is a serine/threonine kinase whose role in neurons is less well characterised. Here we report that mutations in the C. elegans PRKD homolog, dkf-1 , show an acceleration in age-dependent decline of locomotion rate and an alteration to age-dependent changes in aldicarb sensitivity. These effects could be explained by a pre- or post-synaptic function of the protein kinase as the animal ages.

5.
Pathogens ; 12(4)2023 Apr 15.
Article in English | MEDLINE | ID: mdl-37111489

ABSTRACT

An exceptional gut-colonizing ability may underlie the dramatic epidemiological success of the multidrug-resistant H30R subclone of Escherichia coli sequence type 131 (O25b:K+:H4). In order to inform the development of colonization-preventing measures, we studied systemic immune correlates of H30R intestinal colonization. Human volunteers' fecal samples were screened for H30R by selective culture and PCR. Subjects were assessed by enzyme immunoassay for serum levels of anti-O25 IgG (representing H30R) and anti-O6 IgG (representing non-H30 E. coli generally), initially and for up to 14 months. Whole blood was tested for the antigen-stimulated release of IFNγ, TNFα, IL-4, IL-10, and IL-17 after incubation with E. coli strains JJ1886 (H30R; O25b:K+:H4) or CFT073 (non-H30; O6:K2:H1). Three main findings were obtained. First, H30R-colonized subjects had significantly higher anti-O25 IgG levels than controls, but similar anti-O6 IgG levels, suggesting an IgG response to H30R colonization. Second, anti-O25 and anti-O6 IgG levels were stable over time. Third, H30R-colonized subjects exhibited a lower TNFα and IL-10 release than controls in response to strain JJ1886 (H30R) relative to strain CFT073 (non-H30R), consistent with TNFα hypo-responsiveness to H30R possibly predisposing to H30R colonization. Thus, H30R-colonized hosts exhibit a sustained serum anti-O25 IgG response and an underlying deficit in TNFα responsiveness to H30R that could potentially be addressed for colonization prevention.

6.
ASAIO J ; 69(7): 708-715, 2023 07 01.
Article in English | MEDLINE | ID: mdl-37097973

ABSTRACT

Critically ill patients undergoing continuous renal replacement therapy (CRRT) have medical conditions requiring extensive pharmacotherapy. Continuous renal replacement therapy impacts drug disposition. Few data exist regarding drug dosing requirements with contemporary CRRT modalities and effluent rates. The practical limitations of pharmacokinetic studies requiring numerous plasma and effluent samples, and lack of generalizability of observations from specific CRRT prescriptions, highlight gaps in bedside assessment of CRRT drug elimination and individualized dosing needs. We employed a porcine model using transdermal fluorescence detection of the glomerular filtration rate fluorescent tracer agent MB-102, with the aim to assess the relationship between systemic exposure of MB-102 and meropenem during CRRT. Animals underwent bilateral nephrectomies and received intravenous bolus doses of MB-102 and meropenem. Once MB-102 equilibrated in the animal, CRRT was initiated. Continuous renal replacement therapy prescriptions comprised four combinations of blood pump (low versus high) and effluent (low versus high) flow rates. Changes in transdermal detected MB-102 clearance occurred immediately with a change in CRRT rates. Blood side meropenem clearance mirrored transdermal MB-102 clearance ( r2 : 0.95-0.97, p value all <0.001). We suggest transdermal MB-102 clearance provides real-time personalized assessment of drug elimination and could optimize prescription of drugs for critically ill patients requiring CRRT.


Subject(s)
Anti-Bacterial Agents , Continuous Renal Replacement Therapy , Animals , Swine , Meropenem/pharmacokinetics , Anti-Bacterial Agents/pharmacokinetics , Critical Illness , Renal Replacement Therapy/methods
7.
Microb Genom ; 9(2)2023 02.
Article in English | MEDLINE | ID: mdl-36752777

ABSTRACT

ST372 are widely reported as the major Escherichia coli sequence type in dogs globally. They are also a sporadic cause of extraintestinal infections in humans. Despite this, it is unknown whether ST372 strains from dogs and humans represent shared or distinct populations. Furthermore, little is known about genomic traits that might explain the prominence of ST372 in dogs or presence in humans. To address this, we applied a variety of bioinformatics analyses to a global collection of 407 ST372 E. coli whole-genome sequences to characterize their epidemiological features, population structure and associated accessory genomes. We confirm that dogs are the dominant host of ST372 and that clusters within the population structure exhibit distinctive O:H types. One phylogenetic cluster, 'cluster M', comprised almost half of the sequences and showed the divergence of two human-restricted clades that carried different O:H types to the remainder of the cluster. We also present evidence supporting transmission between dogs and humans within different clusters of the phylogeny, including M. We show that multiple acquisitions of the pdu propanediol utilization operon have occurred in clusters dominated by isolates of canine source, possibly linked to diet, whereas loss of the pdu operon and acquisition of K antigen virulence genes characterize human-restricted lineages.


Subject(s)
Escherichia coli Infections , Escherichia coli , Humans , Dogs , Animals , Escherichia coli Infections/veterinary , Phylogeny , Virulence/genetics , Virulence Factors/genetics
8.
Am J Infect Control ; 51(4): 434-439, 2023 04.
Article in English | MEDLINE | ID: mdl-35764181

ABSTRACT

BACKGROUND: Escherichia coli sequence type (ST) ST131, with its emergent resistance-associated H30Rx, H30R1, and C1-M27 clonal subsets, accounts for the greatest share of extraintestinal E. coli infections and most extended-spectrum ß-lactamase (ESBL)-producing E. coli. METHODS: We characterized and compared consecutive E. coli urine isolates from two geographically distinct medical centers in Minneapolis, Minnesota (n = 172) and Boston, Massachusetts (n = 143) for ESBL phenotype, CTX-M-type ESBL genes, phylogenetic groups, selected ST131 subclones, and 40 extraintestinal virulence genes. RESULTS: Whereas the Boston vs. Minneapolis isolates had a similar prevalence of phylogenetic groups (mainly B2: 79% vs 73%), ST131 (34% vs 28%), H30 (28% vs 21%), and H30Rx (6% vs 5%), the emerging C1-M27 subclone occurred uniquely among Boston (6%) isolates. ESBL production was more prevalent among Boston isolates (15% vs 8%) and among ST131 isolates. Identified ESBL genes included blaCTX-M-27 (Boston only) and blaCTX-M-15. Ciprofloxacin resistance was ST131-associated and similarly prevalent across centers. Boston isolates had higher virulence gene scores. CONCLUSIONS: Despite numerous similarities to Minneapolis isolates, Boston ST131 isolates demonstrated more prevalent ESBL production, higher virulence gene scores, and, uniquely, the C1-M27 subclone and blaCTX-M-27. Broader surveillance is needed to define the prevalence of ST131's globally successful C1-M27 subclone across the U.S.


Subject(s)
Escherichia coli Infections , Escherichia coli Proteins , Humans , Escherichia coli/genetics , Anti-Bacterial Agents/pharmacology , Prevalence , Boston/epidemiology , Phylogeny , Escherichia coli Proteins/genetics , Escherichia coli Infections/epidemiology , beta-Lactamases/genetics
9.
Biosensors (Basel) ; 12(9)2022 Aug 28.
Article in English | MEDLINE | ID: mdl-36140078

ABSTRACT

KcapTR488 is a dual-fluorophore peptide sensor for the real-time reporting of programmed cell death by fluorescence imaging. KcapTR488 contains a nuclear localization sequence (NLS) conjugated with Texas Red, a caspase-cleavable sequence (DEVD), and a C-terminus conjugated to Alexa Fluor 488 (AF488). The synthesis and preliminary evaluation in cellulo of KcapTR488 for monitoring cell death by fluorescence imaging has been previously reported, but its utility in vivo has yet to be tested or validated. Herein, in vitro solution experiments verified the intramolecular fluorescence resonance energy transfer (FRET) between the two fluorophores and enabled a quantitative analysis of enzyme rates and selectivity. The sensor delivery kinetics in live rat models were quantified by ex vivo fluorescence microscopy. Studies in healthy control retinas demonstrated that KcapTR488 concentrated in the nucleus of retinal ganglion cells (RGC), with a strong colocalization of red and green fluorescence signals producing robust FRET signals, indicating an intact reporter. By contrast, using an acute but mild NMDA-induced retinal injury model, dual-color confocal ex vivo microscopy of cleaved KcapTR488 identified sensor activation as early as 2 h after injection. Quantitative changes in fluorescence colocalization were superior to changes in FRET for monitoring injury progression. Longitudinal monitoring revealed that the NLS-Texas Red fragment of the cleaved sensor moved out of the cell body, down the axon, and exited the retina, consistent with anterograde axonal transport. Thus, KcapTR488 may be a powerful tool to study RGC death pathways in live preclinical models of glaucoma.


Subject(s)
N-Methylaspartate , Retinal Ganglion Cells , Animals , Apoptosis , Caspases/metabolism , Fluoresceins , Fluorescent Dyes , N-Methylaspartate/pharmacology , Peptides , Rats , Retinal Ganglion Cells/metabolism , Sulfonic Acids
10.
Trop Anim Health Prod ; 54(5): 332, 2022 Sep 30.
Article in English | MEDLINE | ID: mdl-36175571

ABSTRACT

Agricultural use of antimicrobials in food animal production may contribute to the global emergence of antimicrobial resistance (AMR). However, considerable gaps exist in research on the use of antimicrobial drugs (AMDs) in food animals in small-scale production systems in low- and middle-income countries, despite the minimal regulation of antimicrobials in such regions. The aim of this study was to identify factors that may influence AMD use in livestock among pastoral communities in Kenya. We collected data related to household and herd demographics, herd health, and herd management from 55 households in the Maasai Mara ecosystem, Kenya, between 2018 and 2019. We used multi-model logistic regression inference (supervised machine learning) to ascertain trends in AMD use within these households. AMD use in cattle was significantly associated with AMD use in sheep and goats (p = 0.05), implying that decisions regarding AMD use in cattle or sheep and goats were interdependent. AMD use in sheep and goats was negatively associated with vaccination against the foot and mouth disease (FMD) virus in cattle (OR = 0.06, 95% CI 0.01-0.67, p = 0.02). Less AMD use was observed for vaccine-preventable diseases like contagious ecthyma when households had access to state veterinarians (OR = 0.06, p = 0.05, 95% CI 0.004-0.96). Overall, decisions to use AMDs were associated with vaccine usage, occurrence of respiratory diseases, and access to animal health advice. This hypothesis-generating study suggests that applying community-centric methods may be necessary to understand the use of AMDs in pastoral communities.


Subject(s)
Anti-Infective Agents , Foot-and-Mouth Disease Virus , Veterinarians , Animals , Anti-Infective Agents/therapeutic use , Cattle , Ecosystem , Goats , Humans , Kenya/epidemiology , Sheep
11.
Zoonoses Public Health ; 69(7): 888-895, 2022 11.
Article in English | MEDLINE | ID: mdl-35799333

ABSTRACT

Interactions between humans and pets are increasingly valued in western countries, leading to more extensive contact between humans and their pets within households. Although the magnitude of the risk of transfer of Escherichia coli between humans and their companion animals is undefined, that such transmission occurs has been established and warrants attention. This study examined 186 fresh faecal samples from companion dogs visiting 22 municipal dog parks in the Minneapolis/Saint Paul metropolitan area, Minnesota, USA. Samples were processed to isolate 3rd-generation cephalosporin-resistant E. coli, which were further characterized using PCR-based virulence genotyping, antimicrobial susceptibility profiling and whole-genome sequencing. Of the 186 faecal samples, 29% yielded cephalosporin-resistant E. coli, and 2.2% yielded extended-spectrum beta-lactamase producers. Co-resistance to sulfonamides was typical (77.3% of isolates), and multidrug resistance (i.e. to ≥3 antimicrobial classes), including to combinations of tetracyclines, phenicols, quinolones and aminoglycosides, was substantial (18.9% of isolates). Identified beta-lactamase genes included blaCMY-2 , blaTEM-1B , blaTEM-1 , blaCTX-M-24 , blaCTX-M-15 and blaOXA-1 . Genome sequencing of 14 isolates identified genes typical of extraintestinal pathogenic E. coli or enteropathogenic E. coli. In three instances, closely related isolates were recovered from different dogs, within either the same park-suggesting transfer of E. coli between dogs within the park-or different parks-suggesting that dogs may be pre-disposed to carry certain E. coli types, such as those from serogroups O4, O71 and O157. This study adds to the existing evidence that companion dogs can harbour and share antimicrobial-resistant E. coli with presumed intestinal or extraintestinal pathogenic potential.


Subject(s)
Dog Diseases , Enteropathogenic Escherichia coli , Escherichia coli Infections , Quinolones , Aminoglycosides , Animals , Anti-Bacterial Agents/pharmacology , Cephalosporins , Dog Diseases/epidemiology , Dogs , Enteropathogenic Escherichia coli/genetics , Escherichia coli Infections/epidemiology , Escherichia coli Infections/veterinary , Feces , Humans , Minnesota/epidemiology , Pets , Sulfonamides , Tetracyclines , beta-Lactamases/genetics
12.
Microbiol Spectr ; 10(3): e0106422, 2022 06 29.
Article in English | MEDLINE | ID: mdl-35604132

ABSTRACT

Escherichia coli sequence type 131 (ST131) is a pandemic, multidrug-resistant extraintestinal pathogen. The multiple distinctive ST131 subclones differ for rfb and fliC alleles (O and H antigens), fimH allele (type-1 fimbriae adhesin), resistance phenotype and genotype, clinical correlates, and host predilection. Current PCR assays for detecting ST131 and its main subclones offer limited sub-ST characterization. Here we combined 22 novel and 14 published primers for a multiplex PCR assay to detect and extensively characterize ST131 isolates. The primers target mdh36, gyrB47, trpA72, sbmA, plsB, nupC, rmuC, kefC, ybbW, the O16 and O25b rfb variants, five fimH alleles (fimH22, fimH27, fimH30, fimH35, and fimH41), two fliC alleles (H4 and H5), a (subclone-specific) fluoroquinolone resistance-associated parC allele, and a (subclone-specific) prophage marker. The resulting amplicons resolve 15 molecular subsets within ST131, including 3 within clade A (H41 subclone), 5 within clade B (H22 subclone), and 7 within clade C (H30 subclone), which includes subclones C0 (H30S: 2 subsets), C1 and C1-M27 (H30R1: 2 subsets), and C2 (H30Rx: 3 subsets). Validation in three laboratories showed that this assay provides a rapid, accurate, and portable method for rapidly detecting and characterizing E. coli ST131 and its key subsets. Additionally, for users with whole genome sequencing (WGS) capability, we developed a command-line executable called ST131Typer, an in silico version of the extended multiplex PCR assay. Its accuracy was 87.8%, with most issues due to incomplete or fragmented input genome assemblies. These two novel assays should facilitate detailed ST131 subtyping using either endpoint PCR or WGS. IMPORTANCE These novel assays provide greater subclonal resolution and characterization of E. coli ST131 isolates than do the available comparable PCR assays, plus offer a novel sequence-based alternative to PCR. They may prove useful for molecular epidemiological studies, surveillance, and, potentially, clinical management.


Subject(s)
Escherichia coli Infections , Escherichia coli Proteins , Anti-Bacterial Agents , Escherichia coli , Escherichia coli Proteins/genetics , Fluoroquinolones , Genotype , Humans , Multiplex Polymerase Chain Reaction , beta-Lactamases/genetics
13.
Front Microbiol ; 13: 887799, 2022.
Article in English | MEDLINE | ID: mdl-35547133

ABSTRACT

Non-antibiotic measures are needed to reduce the rate of infections due to multidrug-resistant organisms (MDROs), including by eliminating the commensal reservoir that underlies such strains' dissemination and leads to recurrent infections. Here, we tested a cocktail of pre-selected bacteriophages and an engineered microcin C7-producing probiotic Escherichia coli Nissle-1917 strain for their ability to reduce gut colonization by an E. coli strain from sequence type 131 (ST131)-H30R, which is the major clonal group of MDROs among extraintestinal clinical E. coli isolates. Although the bacteriophage cocktail was highly effective against ST131-H30R strains both in vitro and in a murine model of subcutaneous sepsis, it was only weakly and transiently effective against gut colonization by the target ST131-H30R strain (0.5 log10 decrease on d + 1: p < 0.001; no significant effect on d + 4 and beyond). The probiotic strain, while also highly active against ST131-H30R in vitro, was ineffective against ST131-H30R gut colonization despite its abundant presence in feces. Nonetheless, despite failing as decolonizing agents when administered separately, when co-administered the bacteriophage cocktail and probiotic strain exhibited striking synergy against ST131-H30R gut colonization. This combinatory effect was most pronounced on d + 1 (3.3 log10 target strain decrease: p < 0.001), and persisted until d + 7 (0.5 log10 decrease; p < 0.02.). Although by d + 10 the ST131-H30R load was fully restored, these findings provide proof of concept for combined bacteriophage-plus-probiotic administration to reduce or, possibly, to prevent gut colonization with MDROs in high-risk individuals.

14.
mBio ; 13(2): e0362921, 2022 04 26.
Article in English | MEDLINE | ID: mdl-35343789

ABSTRACT

Carboxysomes are anabolic bacterial microcompartments that play an essential role in carbon fixation in cyanobacteria and some chemoautotrophs. This self-assembling organelle encapsulates the key CO2-fixing enzymes, Rubisco, and carbonic anhydrase using a polyhedral protein shell that is constructed by hundreds of shell protein paralogs. The α-carboxysome from the chemoautotroph Halothiobacillus neapolitanus serves as a model system in fundamental studies and synthetic engineering of carboxysomes. In this study, we adopted a QconCAT-based quantitative mass spectrometry approach to determine the stoichiometric composition of native α-carboxysomes from H. neapolitanus. We further performed an in-depth comparison of the protein stoichiometry of native α-carboxysomes and their recombinant counterparts heterologously generated in Escherichia coli to evaluate the structural variability and remodeling of α-carboxysomes. Our results provide insight into the molecular principles that mediate carboxysome assembly, which may aid in rational design and reprogramming of carboxysomes in new contexts for biotechnological applications. IMPORTANCE A wide range of bacteria use special protein-based organelles, termed bacterial microcompartments, to encase enzymes and reactions to increase the efficiency of biological processes. As a model bacterial microcompartment, the carboxysome contains a protein shell filled with the primary carbon fixation enzyme Rubisco. The self-assembling organelle is generated by hundreds of proteins and plays important roles in converting carbon dioxide to sugar, a process known as carbon fixation. In this study, we uncovered the exact stoichiometry of all building components and the structural plasticity of the functional α-carboxysome, using newly developed quantitative mass spectrometry together with biochemistry, electron microscopy, and enzymatic assay. The study advances our understanding of the architecture and modularity of natural carboxysomes. The knowledge learned from natural carboxysomes will suggest feasible ways to produce functional carboxysomes in other hosts, such as crop plants, with the overwhelming goal of boosting cell metabolism and crop yields.


Subject(s)
Carbonic Anhydrases , Halothiobacillus , Carbon Cycle , Carbonic Anhydrases/metabolism , Escherichia coli/genetics , Escherichia coli/metabolism , Halothiobacillus/genetics , Halothiobacillus/metabolism , Organelles , Ribulose-Bisphosphate Carboxylase/genetics , Ribulose-Bisphosphate Carboxylase/metabolism
15.
Angew Chem Int Ed Engl ; 61(14): e202117324, 2022 03 28.
Article in English | MEDLINE | ID: mdl-35138660

ABSTRACT

Carboxyl methyltransferase (CMT) enzymes catalyse the biomethylation of carboxylic acids under aqueous conditions and have potential for use in synthetic enzyme cascades. Herein we report that the enzyme FtpM from Aspergillus fumigatus can methylate a broad range of aromatic mono- and dicarboxylic acids in good to excellent conversions. The enzyme shows high regioselectivity on its natural substrate fumaryl-l-tyrosine, trans, trans-muconic acid and a number of the dicarboxylic acids tested. Dicarboxylic acids are generally better substrates than monocarboxylic acids, although some substituents are able to compensate for the absence of a second acid group. For dicarboxylic acids, the second methylation shows strong pH dependency with an optimum at pH 5.5-6. Potential for application in industrial biotechnology was demonstrated in a cascade for the production of a bioplastics precursor (FDME) from bioderived 5-hydroxymethylfurfural (HMF).


Subject(s)
Esters , Methyltransferases , Aspergillus fumigatus , Biocatalysis , Catalysis , Dicarboxylic Acids , Methyltransferases/chemistry
16.
J Infect Dis ; 225(12): 2197-2207, 2022 06 15.
Article in English | MEDLINE | ID: mdl-34979558

ABSTRACT

BACKGROUND: Superior gut colonization may underlie the pandemic emergence of the resistance-associated H30 subclone of Escherichia coli sequence type 131 (ST131-H30). Little is known about the associated host and bacterial characteristics, or the comparative persistence of non-ST131 intestinal E. coli. METHODS: Generic and fluoroquinolone-resistant E. coli isolates from volunteers' serial fecal samples underwent clonal analysis and extensive polymerase chain reaction (PCR)-based characterization (phylogroup, selected sequence types, virulence genes). Kaplan-Meier survival analysis and Cox proportional hazards survival analysis using penalized regression (a machine-learning method) were used to identify correlates of strain persistence. RESULTS: Screening of 2005 subjects at the Minneapolis VA Medical Center identified 222 subjects (117 veterans, 105 human and animal household members) for longitudinal fecal surveillance. Analysis of their 585 unique-by-subject fecal E. coli strains identified multiple epidemiological, ecological, and bacterial correlates of strain persistence. ST131-H30, a strong univariable correlate of persistence, was superseded in multivariable analysis by outpatient status, fluoroquinolone resistance, and diverse (predominantly iron uptake-related) virulence genes. CONCLUSIONS: ST131-H30 exhibits exceptional intestinal persistence, possibly due to a combination of fluoroquinolone resistance and virulence factors, which may be primarily colonization factors. This identifies both likely contributors to the ST131-H30 pandemic and potential targets for interventions against it.


Subject(s)
Escherichia coli Infections , Escherichia coli , Animals , Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial/genetics , Escherichia coli Infections/epidemiology , Escherichia coli Infections/microbiology , Fluoroquinolones/pharmacology , Genotype , Humans , beta-Lactamases/genetics
17.
Disabil Rehabil Assist Technol ; 17(4): 449-452, 2022 05.
Article in English | MEDLINE | ID: mdl-32620066

ABSTRACT

OBJECTIVE: To determine whether bacterial contamination of rider's hands is less with a novel ergonomic wheelchair (EW) than a standard wheelchair (SW). EXPERIMENTAL DESIGN: After wheelchair hand rims were disinfected, volunteers wearing nitrile gloves propelled each wheelchair through a standardised "run" in hospital. Post-run cultures were obtained from riders' gloved hands. Bacterial hand counts were compared between runs matched by rider (same rider, different chairs) or time (different riders in each chair, running concurrently), and overall. SETTING: Minneapolis Veterans Affairs Health Care System (MVAHCS), a large tertiary care facility. PARTICIPANTS: Eleven employee volunteers. INTERVENTION: EW, as compared with SW. With SW, co-location of hand rims and tyres potentially exposes the user's hands to tyres, which risks contaminating the user's hands with ground-source bacteria. Our novel ergonomic wheelchair (EW) separates drive wheel and hand rims, potentially reducing hand contamination. MAIN OUTCOME MEASURE: Bacterial hand counts. RESULTS: Post-run bacterial hand counts were over 10-fold lower with the EW than the SW. This was true (i) when the same rider tested both chairs sequentially (n = 8 pairs) (median counts, 40 vs. 1030; p = 0.008), (ii) when different riders tested the two chairs concurrently (n = 9 pairs) (median counts, 40 vs. 660; p = 0.004), and (iii) overall (median counts, 40 [n = 9 runs] vs. 550 [n = 10 runs]; p < 0.001). CONCLUSION: Separation of wheelchair hand rims from tyres significantly reduces bacterial hand contamination. Reduced hand contamination could decrease bacterial infections and dissemination of resistant bacteria, warranting further study.Implications for rehabilitationThe novel design of the ergonomic wheelchair, removing the push rim from proximity to the wheelchair tyre, keeps the hands of wheelchair users cleaner.The re-design of the standard manual wheelchair was implemented initially to improve shoulder ergonomics during manual wheelchair propulsion and has the added benefit of reduction in the transfer of bacteria from floors to hands for manual wheelchair users.Since the ergonomic wheelchair has the potential to decrease rates of bacterial infection in manual wheelchair users, further testing is warranted.


Subject(s)
Wheelchairs , Bacteria , Biomechanical Phenomena , Ergonomics , Hand , Humans , Upper Extremity
18.
Fed Pract ; 39(12): 482-485, 2022 Dec.
Article in English | MEDLINE | ID: mdl-37025983

ABSTRACT

Background: Aerococcus urinae (A urinae), considered a rare pathogen, has been identified with increasing frequency in urine cultures. Only 8 cases of spondylodiscitis due to A urinae have been reported. Optimal treatment for invasive A urinae infection is undefined. However, the reported cases were treated successfully with diverse antibiotic regimen combinations, all including a ß-lactam and beginning with at least 2 weeks of IV antibiotics. Case Presentation: A 74-year-old man presented to the emergency department after 2 weeks of midthoracic back pain, lower extremity weakness, gait imbalance, fatigue, anorexia, rigors, and subjective fevers. The patient was presumed to have discitis secondary to a urinary tract infection with possible pyelonephritis and was given empiric vancomycin and ceftriaxone. Spinal magnetic resonance imaging with contrast supported spondylodiscitis. Preliminary results from the admission blood and urine cultures showed gram-positive cocci in clusters. Conclusions: A urinae urinary tract infection in the absence of obvious predisposing factors should prompt evaluation for urinary outflow obstruction. We suspect a review of a US Department of Veterans Affairs population might uncover a higher incidence of A urinae infection than previously suspected.

20.
Cureus ; 13(9): e17774, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34659985

ABSTRACT

Aspergillus spp. are ubiquitous molds that cause a wide range of clinical syndromes depending on the immune status of the host. Herein, we present a case of a patient with rheumatoid arthritis on long-term immunosuppressive medications, with a persistent dry cough and left-sided chest pain for over a year, who presented with acute sternal drainage. Computed tomography of the chest showed chronic pulmonary abnormalities, parasternal fluid, and bone destruction of the distal sternum and left sixth rib. The patient underwent debridement; sternal biopsy tissue showed septate hyphae with acute-angled branching, and Aspergillus fumigatus grew in culture. We suspected that the patient developed chronic necrotizing pulmonary aspergillosis (CNPA) that traversed tissue planes and caused chest wall osteomyelitis. The patient received voriconazole and surgical debridement, with clinical and radiological improvement. This case demonstrates the importance of considering CNPA as a diagnosis in patients with moderate degrees of immunosuppression and chronic respiratory symptoms, and Aspergillus spp. as an etiology of osteomyelitis in such patients.

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