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"Mathias, Jordan"
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Acquisition of Escherichia coli carrying extended-spectrum ß-lactamase and carbapenemase genes by hospitalised children with severe acute malnutrition in Niger
2025
Hospitalisation and routine antibiotic treatment are recommended for children with complicated severe acute malnutrition (SAM) but this may exacerbate antimicrobial resistance. Here, we investigate carriage of Gram-negative bacteria in children under five years of age receiving treatment for SAM in Niger, comparing the frequency of colonisation with bacteria carrying resistance genes at admission, during hospital stay and at discharge.
E. coli
isolates carrying a
bla
NDM-5
gene were selected for whole-genome sequencing. Rectal colonisation with bacteria carrying ß-lactamase genes is high, with 76% (n = 1042/1371) of children harbouring bacteria carrying a
bla
CTXM-1
-group gene and 25% (n = 338/1371) carrying a
bla
NDM-5
gene. Over two-thirds of children who did not carry bacteria with a carbapenemase gene at admission are colonised with bacteria carrying a carbapenemase gene at discharge (n = 503/729, 69%).
E. coli
ST167 carrying
bla
NDM-5
gene is recovered from 11% (n = 144/1371) of children. Here we highlight infection control and bacterial AMR transmission concerns amongst a vulnerable population in need of medical treatment.
Hospital treatment for children with severe malnutrition may facilitate antibiotic resistance. Here, using rectal swabs from 1,371 children receiving treatment for severe acute malnutrition in Niger, the authors identify high rates of bacteria carrying carbapenemase genes, highlighting the urgent need to prioritize infection control.
Journal Article
Fate of antibiotic resistant E. coli and antibiotic resistance genes during full scale conventional and advanced anaerobic digestion of sewage sludge
by
Lee, Do-Hoon
,
Cha, Chang-Jun
,
Dinsdale, Richard
in
Abundance
,
Agricultural land
,
Anaerobic bacteria
2020
Antibiotic resistant bacteria (ARB) and their genes (ARGs) have become recognised as significant emerging environmental pollutants. ARB and ARGs in sewage sludge can be transmitted back to humans via the food chain when sludge is recycled to agricultural land, making sludge treatment key to control the release of ARB and ARGs to the environment. This study investigated the fate of antibiotic resistant Escherichia coli and a large set of antibiotic resistance genes (ARGs) during full scale anaerobic digestion (AD) of sewage sludge at two U.K. wastewater treatment plants and evaluated the impact of thermal hydrolysis (TH) pre-treatment on their abundance and diversity. Absolute abundance of 13 ARGs and the Class I integron gene intI1 was calculated using single gene quantitative (q) PCR. High through-put qPCR analysis was also used to determine the relative abundance of 370 ARGs and mobile genetic elements (MGEs). Results revealed that TH reduced the absolute abundance of all ARGs tested and intI1 by 10–12 , 000 fold . After subsequent AD, a rebound effect was seen in many ARGs. The fate of ARGs during AD without pre-treatment was variable. Relative abundance of most ARGs and MGEs decreased or fluctuated, with the exception of macrolide resistance genes, which were enriched at both plants, and tetracyline and glycopeptide resistance genes which were enriched in the plant employing TH. Diversity of ARGs and MGEs decreased in both plants during sludge treatment. Principal coordinates analysis revealed that ARGs are clearly distinguished according to treatment step, whereas MGEs in digested sludge cluster according to site. This study provides a comprehensive within-digestor analysis of the fate of ARGs, MGEs and antibiotic resistant E . coli and highlights the effectiveness of AD, particularly when TH is used as a pre-treatment, at reducing the abundance of most ARGs and MGEs in sludgeand preventing their release into the environment.
Journal Article
Characterization of antimicrobial-resistant Gram-negative bacteria that cause neonatal sepsis in seven low- and middle-income countries
2021
Antimicrobial resistance in neonatal sepsis is rising, yet mechanisms of resistance that often spread between species via mobile genetic elements, ultimately limiting treatments in low- and middle-income countries (LMICs), are poorly characterized. The Burden of Antibiotic Resistance in Neonates from Developing Societies (BARNARDS) network was initiated to characterize the cause and burden of antimicrobial resistance in neonatal sepsis for seven LMICs in Africa and South Asia. A total of 36,285 neonates were enrolled in the BARNARDS study between November 2015 and December 2017, of whom 2,483 were diagnosed with culture-confirmed sepsis.
Klebsiella pneumoniae
(
n
= 258) was the main cause of neonatal sepsis, with
Serratia marcescens
(
n
= 151),
Klebsiella michiganensis
(
n
= 117),
Escherichia coli
(
n
= 75) and
Enterobacter cloacae
complex (
n
= 57) also detected. We present whole-genome sequencing, antimicrobial susceptibility and clinical data for 916 out of 1,038 neonatal sepsis isolates (97 isolates were not recovered from initial isolation at local sites). Enterobacterales (
K. pneumoniae, E. coli
and
E. cloacae
) harboured multiple cephalosporin and carbapenem resistance genes. All isolated pathogens were resistant to multiple antibiotic classes, including those used to treat neonatal sepsis. Intraspecies diversity of
K. pneumoniae
and
E. coli
indicated that multiple antibiotic-resistant lineages cause neonatal sepsis. Our results will underpin research towards better treatments for neonatal sepsis in LMICs.
Genomic and clinical analysis of 916 bacterial isolates from neonates with sepsis in seven low- and middle-income countries (the BARNARDS study) reveals that the main species present were antimicrobial-resistant
Klebsiella
,
Escherichia coli
and
Enterobacter
.
Journal Article
Effective phage cocktail to combat the rising incidence of extensively drug-resistant Klebsiella pneumoniae sequence type 16
by
Hunter, James R.
,
Gales, Ana C.
,
Li, Mei
in
Anti-Bacterial Agents - pharmacology
,
Antibiotics
,
Antimicrobial Agents
2022
Bacteriophages are the most abundant organisms on Earth. As there are few effective treatment options against some pathogens, the interest in the bacteriophage control of multi-drug-resistant bacterial pathogens is escalating, especially for Klebsiella pneumoniae. This study aimed to develop a phage-based solution to the rising incidence of extensively drug-resistant clinical Klebsiella pneumoniae sequence type (ST16) infections starting from a set of phages recently characterized against this lineage. A phage-cocktail (Katrice-16) composed of eight lytic phages was characterized for potential use in humans. In vitro and in vivo broth inhibition and Galleria mellonella rescue assays were used to demonstrate the efficacy of this approach using a collection of 56 strains of K. pneumoniae ST16, with distinct genetic backgrounds that were collected from clinical infections from four disparate nations. Additionally, Katrice-16 anti-biofilm activity, synergism with meropenem, and activity in human body fluids were also assessed. Katrice-16 was highly active in vitro against our K. pneumoniae ST16 collection (AUC% median = 86.48%; Q1 = 83.8%; Q2 = 96.85%; Q3 = 98.85%). It additionally demonstrated excellent in vivo activity in G. mellonella rescue assays, even with larvae infected by isolates that exhibited moderate in vitro inhibition. We measured significant anti-biofilm activity over 12 h (p = .0113) and synergic activity with meropenem. In addition, we also demonstrate that Katrice-16 maintained high activity in human body fluids. Our results indicate that our cocktail will likely be an effective solution for human infections with this increasingly prevalent and often highly resistant bacterial clone.
Journal Article
Characterisation of Staphylococci species from neonatal blood cultures in low- and middle-income countries
by
Spiller, Owen B.
,
Watkins, William John
,
Akpulu, Chinenye
in
Antibiotic resistance
,
Antibiotics
,
Antimicrobial agents
2022
Background
In low- and middle-income countries (LMIC)
Staphylococcus aureus
is regarded as one of the leading bacterial causes of neonatal sepsis, however there is limited knowledge on the species diversity and antimicrobial resistance caused by Gram-positive bacteria (GPB).
Methods
We characterised GPB isolates from neonatal blood cultures from LMICs in Africa (Ethiopia, Nigeria, Rwanda, and South Africa) and South-Asia (Bangladesh and Pakistan) between 2015–2017. We determined minimum inhibitory concentrations and performed whole genome sequencing (WGS) on Staphylococci isolates recovered and clinical data collected related to the onset of sepsis and the outcome of the neonate up to 60 days of age.
Results
From the isolates recovered from blood cultures, Staphylococci species were most frequently identified. Out of 100
S. aureus
isolates sequenced, 18 different sequence types (ST) were found which unveiled two small epidemiological clusters caused by methicillin resistant
S. aureus
(MRSA) in Pakistan (ST8) and South Africa (ST5)
,
both with high mortality (n = 6/17). One-third of
S. aureus
was MRSA, with methicillin resistance also detected in
Staphylococcus epidermidis, Staphylococcus haemolyticus
and
Mammaliicoccus sciuri.
Through additional WGS analysis we report a cluster of
M. sciuri
in Pakistan identified between July-November 2017.
Conclusions
In total we identified 14 different GPB bacterial species, however Staphylococci was dominant. These findings highlight the need of a prospective genomic epidemiology study to comprehensively assess the true burden of GPB neonatal sepsis focusing specifically on mechanisms of resistance and virulence across species and in relation to neonatal outcome.
Journal Article
‘Superbugs’: raising public awareness of antimicrobial resistance through a pop-up science shop
by
Eberl, Matthias
,
Tyrrell, Jonathan M.
,
Hatch, Sarah
in
antibiotic stewardship
,
Antibiotics
,
Antimicrobial agents
2022
‘Superbugs: A Pop-up Science Shop’ was a public engagement event in the school summer holidays of 2019, organised by members of Cardiff University’s School of Medicine. We transformed an empty retail unit in the centre of Wales’s largest shopping centre into an interactive and immersive microbiology experience. We facilitated two-way dialogue to impart positive impact on the awareness of antibiotic resistance, while concurrently evaluating the efficacy of an engagement strategy focused on the utilisation of public spaces to attract public demographics diverse to those who would normally engage with conventional science, technology, engineering and mathematics (STEM) outreach. Over the course of 14 days, we welcomed 6,566 visitors, with 67 per cent attending as part of the natural footfall of the shopping centre. We created 1,626 young Antibiotic Resistance Champions, located in over two hundred schools, across many of the most deprived areas in Wales. We imparted a positive impact to our stakeholders, with a significant increase in the knowledge and understanding of the subject of antimicrobial resistance (AMR); 91.7 per cent indicated that they had a better understanding after the event. In this article, we discuss the evolution of ‘Superbugs’ from concept, planning and design, to the logistics of delivering an engagement event of this scale. We focus in particular on the learning outcomes of the project, and on how this will shape the future of our ‘Superbugs’ project, and engagement events beyond.
Journal Article
Exoskeleton Technology in Rehabilitation : Towards an EMG-Based Orthosis System for Upper Limb Neuromotor Rehabilitation
2013
The rehabilitation of patients should not only be limited to the first phases during intense hospital care but also support and therapy should be guaranteed in later stages, especially during daily life activities if the patient’s state requires this. However, aid should only be given to the patient if needed and as much as it is required. To allow this, automatic self-initiated movement support and patient-cooperative control strategies have to be developed and integrated into assistive systems. In this work, we first give an overview of different kinds of neuromuscular diseases, review different forms of therapy, and explain possible fields of rehabilitation and benefits of robotic aided rehabilitation. Next, the mechanical design and control scheme of an upper limb orthosis for rehabilitation are presented. Two control models for the orthosis are explained which compute the triggering function and the level of assistance provided by the device. As input to the model fused sensor data from the orthosis and physiology data in terms of electromyography (EMG) signals are used.
Journal Article
Effects of antibiotic resistance, drug target attainment, bacterial pathogenicity and virulence, and antibiotic access and affordability on outcomes in neonatal sepsis: an international microbiology and drug evaluation prospective substudy (BARNARDS)
by
Haileselassie, Misgana
,
Yakubu, Samuel
,
Iregbu, Kenneth C.
in
Accessibility
,
Amikacin
,
Amoxicillin
2021
Sepsis is a major contributor to neonatal mortality, particularly in low-income and middle-income countries (LMICs). WHO advocates ampicillin–gentamicin as first-line therapy for the management of neonatal sepsis. In the BARNARDS observational cohort study of neonatal sepsis and antimicrobial resistance in LMICs, common sepsis pathogens were characterised via whole genome sequencing (WGS) and antimicrobial resistance profiles. In this substudy of BARNARDS, we aimed to assess the use and efficacy of empirical antibiotic therapies commonly used in LMICs for neonatal sepsis.
In BARNARDS, consenting mother–neonates aged 0–60 days dyads were enrolled on delivery or neonatal presentation with suspected sepsis at 12 BARNARDS clinical sites in Bangladesh, Ethiopia, India, Pakistan, Nigeria, Rwanda, and South Africa. Stillborn babies were excluded from the study. Blood samples were collected from neonates presenting with clinical signs of sepsis, and WGS and minimum inhibitory concentrations for antibiotic treatment were determined for bacterial isolates from culture-confirmed sepsis. Neonatal outcome data were collected following enrolment until 60 days of life. Antibiotic usage and neonatal outcome data were assessed. Survival analyses were adjusted to take into account potential clinical confounding variables related to the birth and pathogen. Additionally, resistance profiles, pharmacokinetic–pharmacodynamic probability of target attainment, and frequency of resistance (ie, resistance defined by in-vitro growth of isolates when challenged by antibiotics) were assessed. Questionnaires on health structures and antibiotic costs evaluated accessibility and affordability.
Between Nov 12, 2015, and Feb 1, 2018, 36 285 neonates were enrolled into the main BARNARDS study, of whom 9874 had clinically diagnosed sepsis and 5749 had available antibiotic data. The four most commonly prescribed antibiotic combinations given to 4451 neonates (77·42%) of 5749 were ampicillin–gentamicin, ceftazidime–amikacin, piperacillin–tazobactam–amikacin, and amoxicillin clavulanate–amikacin. This dataset assessed 476 prescriptions for 442 neonates treated with one of these antibiotic combinations with WGS data (all BARNARDS countries were represented in this subset except India). Multiple pathogens were isolated, totalling 457 isolates. Reported mortality was lower for neonates treated with ceftazidime–amikacin than for neonates treated with ampicillin–gentamicin (hazard ratio [adjusted for clinical variables considered potential confounders to outcomes] 0·32, 95% CI 0·14–0·72; p=0·0060). Of 390 Gram-negative isolates, 379 (97·2%) were resistant to ampicillin and 274 (70·3%) were resistant to gentamicin. Susceptibility of Gram-negative isolates to at least one antibiotic in a treatment combination was noted in 111 (28·5%) to ampicillin–gentamicin; 286 (73·3%) to amoxicillin clavulanate–amikacin; 301 (77·2%) to ceftazidime–amikacin; and 312 (80·0%) to piperacillin–tazobactam–amikacin. A probability of target attainment of 80% or more was noted in 26 neonates (33·7% [SD 0·59]) of 78 with ampicillin–gentamicin; 15 (68·0% [3·84]) of 27 with amoxicillin clavulanate–amikacin; 93 (92·7% [0·24]) of 109 with ceftazidime–amikacin; and 70 (85·3% [0·47]) of 76 with piperacillin–tazobactam–amikacin. However, antibiotic and country effects could not be distinguished. Frequency of resistance was recorded most frequently with fosfomycin (in 78 isolates [68·4%] of 114), followed by colistin (55 isolates [57·3%] of 96), and gentamicin (62 isolates [53·0%] of 117). Sites in six of the seven countries (excluding South Africa) stated that the cost of antibiotics would influence treatment of neonatal sepsis.
Our data raise questions about the empirical use of combined ampicillin–gentamicin for neonatal sepsis in LMICs because of its high resistance and high rates of frequency of resistance and low probability of target attainment. Accessibility and affordability need to be considered when advocating antibiotic treatments with variance in economic health structures across LMICs.
The Bill & Melinda Gates Foundation.
Journal Article
Colonisation of hospital surfaces from low- and middle-income countries by extended spectrum β-lactamase- and carbapenemase-producing bacteria
2024
Hospital surfaces can harbour bacterial pathogens, which may disseminate and cause nosocomial infections, contributing towards mortality in low- and middle-income countries (LMICs). During the BARNARDS study, hospital surfaces from neonatal wards were sampled to assess the degree of environmental surface and patient care equipment colonisation by Gram-negative bacteria (GNB) carrying antibiotic resistance genes (ARGs). Here, we perform PCR screening for extended-spectrum β-lactamases (
bla
CTX-M-15
) and carbapenemases (
bla
NDM
,
bla
OXA-48
-like and
bla
KPC
), MALDI-TOF MS identification of GNB carrying ARGs, and further analysis by whole genome sequencing of bacterial isolates. We determine presence of consistently dominant clones and their relatedness to strains causing neonatal sepsis. Higher prevalence of carbapenemases is observed in Pakistan, Bangladesh, and Ethiopia, compared to other countries, and are mostly found in surfaces near the sink drain.
Klebsiella pneumoniae
,
Enterobacter hormaechei
,
Acinetobacter baumannii
,
Serratia marcescens
and
Leclercia adecarboxylata
are dominant; ST15
K. pneumoniae
is identified from the same ward on multiple occasions suggesting clonal persistence within the same environment, and is found to be identical to isolates causing neonatal sepsis in Pakistan over similar time periods. Our data suggests persistence of dominant clones across multiple time points, highlighting the need for assessment of Infection Prevention and Control guidelines.
In hospitals, surfaces present as a reservoir for bacteria pathogens, potentially leading to nosocomial infections. In this work, authors aim to profile extended-spectrum β lactamase- and carbapenemase-carrying bacterial species colonising neonatal hospital wards and causing neonatal sepsis.
Journal Article
Measuring the Improvement of the Interaction Comfort of a Wearable Exoskeleton
by
Kim, Su Kyoung
,
Straube Sirko
,
Kirchner, Elsa Andrea
in
Architecture
,
Comfort
,
Electroencephalography
2012
This paper presents a study conducted to evaluate and optimize the interaction experience between a human and a 9 DOF arm-exoskeleton by the integration of predictions based on electroencephalographic signals (EEG). Due to an ergonomic kinematic architecture and the presence of three contact points, which enable the reflection of complex force patterns, the developed exoskeleton takes full advantage of the human arm mobility, allowing the operator to tele-control complex robotic systems in an intuitive way via an immersive simulation environment. Taking into account the operator’s percept and a set of constraints on the exoskeleton control system, it is illustrated how to quantitatively enhance the comfort and the performance of this sophisticated human–machine interface. Our approach of integrating EEG signals into the control of the exoskeleton guarantees the safety of the operator in any working modality, while reducing effort and ensuring functionality and comfort even in case of possible misclassification of the EEG instances. Tests on different subjects with simulated movement prediction values were performed in order to prove that the integration of EEG signals into the control architecture can significantly smooth the transition between the control states of the exoskeleton, as revealed by a significant decrease in the interaction force.
Journal Article