Meric G.,University of Swansea |
Miragaia M.,New University of Lisbon |
De Been M.,University Utrecht |
Yahara K.,University of Swansea |
And 20 more authors.
Genome Biology and Evolution | Year: 2015
The opportunistic pathogens Staphylococcus aureus and Staphylococcus epidermidis represent major causes of severe nosocomial infection, and are associated with high levels of mortality and morbidity worldwide. These species are both common commensals on the human skin and in the nasal pharynx, but are genetically distinct, differing at 24% average nucleotide divergence in 1,478 core genes. To better understand the genome dynamics of these ecologically similar staphylococcal species, we carried out a comparative analysis of 324 S. aureus and S. epidermidis genomes, including 83 novel S. epidermidis sequences. A reference pan-genome approach and whole genome multilocus-sequence typing revealed that around half of the genome was shared between the species. Based on a BratNextGen analysis, homologous recombination was found to have impacted on 40% of the core genes in S. epidermidis, but on only 24% of the core genes in S. aureus. Homologous recombination between the species is rare, with a maximum of nine gene alleles shared between any two S. epidermidis and S. aureus isolates. In contrast, there was considerable interspecies admixture of mobile elements, in particular genes associated with the SaPIn1 pathogenicity island, metal detoxification, and the methicillin-resistance island SCCmec. Our data and analysis provide a context for considering the nature of recombinational boundaries between S. aureus and S. epidermidis and, the selective forces that influence realized recombination between these species. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
A high-dose preparation of lactobacilli and bifidobacteria in the prevention of antibiotic-associated and clostridium difficile diarrhoea in older people admitted to hospital: A multicentre, randomised, double-blind, placebo-controlled, parallel arm trial (PLACIDE)
Allen S.J.,University of Swansea |
Wareham K.,Morriston Hospital |
Wang D.,London School of Hygiene and Tropical Medicine |
Bradley C.,Darlington Memorial Hospital |
And 10 more authors.
Health Technology Assessment | Year: 2013
Background: Antibiotic-associated diarrhoea (AAD) occurs most commonly in older people admitted to hospital and within 12 weeks of exposure to broad-spectrum antibiotics. Although usually a mild and self-limiting illness, the 15-39% of cases caused by Clostridium difficile infection [C. difficile diarrhoea (CDD)] may result in severe diarrhoea and death. Previous research has shown that probiotics, live microbial organisms that, when administered in adequate numbers, are beneficial to health, may be effective in preventing AAD and CDD. Objectives: To determine the clinical effectiveness and cost-effectiveness of a high-dose, multistrain probiotic in the prevention of AAD and CDD in older people admitted to hospital. Design: A multicentre, randomised, double-blind, placebo-controlled, parallel-arm trial. Setting: Medical, surgical and elderly care inpatient wards in five NHS hospitals in the UK. Participants: Eligible patients were aged ≥ 65 years, were exposed to one or more oral or parenteral antibiotics and were without pre-existing diarrhoeal disorders, recent CDD or at risk of probiotic adverse effects. Out of 17,420 patients screened, 2981 (17.1%) were recruited. Participants were allocated sequentially according to a computer-generated random allocation sequence; 1493 (50.1%) were allocated to the probiotic and 1488 (49.9%) to the placebo arm. Interventions: Vegetarian capsules containing two strains of lactobacilli and two strains of bifidobacteria (a total of 6 × 1010 organisms per day) were taken daily for 21 days. The placebo was inert maltodextrin powder in identical capsules. Main outcome measures: The occurrence of AAD within 8 weeks and CDD within 12 weeks of recruitment was determined by participant follow-up and checking hospital laboratory records by research nurses who were blind to arm allocation. Results: Analysis based on the treatment allocated included 2941 (98.7%) participants. Potential risk factors for AAD at baseline were similar in the two study arms. Frequency of AAD (including CDD) was similar in the probiotic (159/1470, 10.8%) and placebo arms [153/1471, 10.4%; relative risk (RR) 1.04; 95% confidence interval (CI) 0.84 to 1.28; p = 0.71]. CDD was an uncommon cause of AAD and occurred in 12/1470 (0.8%) participants in the probiotic and 17/1471 (1.2%) in the placebo arm (RR 0.71; 95% CI 0.34 to 1.47; p = 0.35). Duration and severity of diarrhoea, common gastrointestinal symptoms, serious adverse events and quality of life measures were also similar in the two arms. Total health-care costs per patient did not differ significantly between the probiotic (£8020; 95% CI £7620 to £8420) and placebo (£8010; 95% CI £7600 to £8420) arms. Conclusion: We found no evidence that probiotic administration was effective in preventing AAD. Although there was a trend towards reduced CDD in the probiotic arm, on balance, the administration of this probiotic seems unlikely to benefit older patients exposed to antibiotics. A better understanding of the pathogenesis of AAD and CDD and the strain-specific effects of probiotics is needed before further clinical trials of specific microbial preparations are undertaken. Evaluation of the effectiveness of other probiotics will be difficult where other measures, such as antibiotic stewardship, have reduced CDD rates. © Queen's Printer and Controller of HMSO 2013.
Harris L.G.,University of Swansea |
Murray S.,University of Swansea |
Pascoe B.,University of Swansea |
Bray J.,University of Oxford |
And 19 more authors.
PLoS ONE | Year: 2016
Bacterial species comprise related genotypes that can display divergent phenotypes with important clinical implications. Staphylococcus epidermidis is a common cause of nosocomial infections and, critical to its pathogenesis, is its ability to adhere and form biofilms on surfaces, thereby moderating the effect of the host's immune response and antibiotics. Commensal S. epidermidis populations are thought to differ from those associated with disease in factors involved in adhesion and biofilm accumulation. We quantified the differences in biofilm formation in 98 S. epidermidis isolates from various sources, and investigated population structure based on ribosomal multilocus typing (rMLST) and the presence/absence of genes involved in adhesion and biofilm formation. All isolates were able to adhere and form biofilms in in vitro growth assays and confocal microscopy allowed classification into 5 biofilm morphotypes based on their thickness, biovolume and roughness. Phylogenetic reconstruction grouped isolates into three separate clades, with the isolates in the main disease associated clade displaying diversity in morphotype. Of the biofilm morphology characteristics, only biofilm thickness had a significant association with clade distribution. The distribution of some known adhesion-associated genes (aap and sesE) among isolates showed a significant association with the species clonal frame. These data challenge the assumption that biofilm-associated genes, such as those on the ica operon, are genetic markers for less invasive S. epidermidis isolates, and suggest that phenotypic characteristics, such as adhesion and biofilm formation, are not fixed by clonal descent but are influenced by the presence of various genes that are mobile among lineages. © 2016 Harris et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Harris L.G.,University of Swansea |
Nigam Y.,University of Swansea |
Sawyer J.,University of Swansea |
Mack D.,University of Swansea |
And 2 more authors.
Applied and Environmental Microbiology | Year: 2013
Staphylococcus aureus and Staphylococcus epidermidis biofilms cause chronic infections due to their ability to form biofilms. The excretions/secretions of Lucilia sericata larvae (maggots) have effective activity for debridement and disruption of bacterial biofilms. In this paper, we demonstrate how chymotrypsin derived from maggot excretions/secretions disrupts protein-dependent bacterial biofilm formation mechanisms. © 2013, American Society for Microbiology.
AL-Ishaq R.,University of Swansea |
Armstrong J.,University of Swansea |
Gregory M.,University of Swansea |
O'Hara M.,University of Swansea |
And 8 more authors.
International Journal of Medical Microbiology | Year: 2015
Background: A major complication of using medical devices is the development of biofilm-associated infection caused by Staphylococcus epidermidis where polysaccharide intercellular adhesin (PIA) is a major mechanism of biofilm accumulation. PIA affects innate and humoral immunity in isolated cells and animal models. Few studies have examined these effects in prosthetic joint infection (PJI). Methods: This study used ex vivo whole blood modelling in controls together with matched-serum and staphylococcal isolates from patients with PJI. Results: Whole blood killing of PIA positive S. epidermidis and its isogenic negative mutant was identical. Differences were unmasked in immunosuppressed whole blood pre-treated with dexamethasone where PIA positive bacteria showed a more resistant phenotype. PIA expression was identified in three unique patterns associated with bacteria and leukocytes, implicating a soluble form of PIA. Purified PIA reduced whole blood killing while increasing C5a levels. In clinically relevant staphylococcal isolates and serum samples from PJI patients; firstly complement C5a was increased 3-fold compared to controls; secondly, the C5a levels were significantly higher in serum from PJI patients whose isolates preferentially formed PIA-associated biofilms. Conclusions: These data demonstrate for the first time that the biological effects of PIA are mediated through C5a in patients with PJI. © 2015 Elsevier GmbH.
Pascoe B.,University of Swansea |
Dams L.,University of Swansea |
Wilkinson T.S.,University of Swansea |
Harris L.G.,University of Swansea |
And 6 more authors.
PLoS ONE | Year: 2014
We describe the first in vitro model of dormancy in Staphylococcus aureus, showing that cells are generated which can be resuscitated by addition of spent medium supernatant taken from cultures of the same organism. Over 30 days, culturable counts in dormant cultures of S. aureus SH1000 fell from 10 6-107 cfu/ml to <10 cfu/ml as measured by the Most Probable Number method in liquid culture, while total counts as determined by microscopy, and supported by data from RT-qPCR, remained around 10 6-107 cells/ml. Supplementing cultures with 25-50% spent medium resulted in a >600-fold increase in bacterial growth. Resuscitation was a specific effect, greatly reduced by boiling or addition of trypsin to the spent supernatant. Supernatant also effected a reduction in lag phase of dormant cultures. SEM demonstrated the presence of small coccoid cells in dormant cultures. The results are similar to those seen with resuscitation promoting factors (Rpfs) in actinobacteria. This is the first time resuscitation has been demonstrated in Staphylococcus aureus, which is an important human pathogen. A better understanding of control and reactivation of dormant cells could lead to major improvements in managing staphylococcal infections; resuscitation could be an important step in restoring susceptibility to antibiotic treatment. © 2014 Pascoe et al.
Multidrug-Resistant Organisms (MDRO) in Rehabilitation Clinics in the Rhine-Main-District, Germany, 2014: Prevalence and Risk Factors [Multiresistente Erreger in Rehabilitationseinrichtungen im Rhein-Main-Gebiet, Deutschland, 2014: I. Prävalenz und Risikofaktoren]
Heudorf U.,MRE Netz Rhein Main |
Farber D.,MRE Netz Rhein Main |
Mischler D.,MRE Netz Rhein Main |
Schade M.,MRE Netz Rhein Main |
And 4 more authors.
Rehabilitation (Germany) | Year: 2015
Background: While a limited number of studies have investigated the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in medical rehabilitation institutions, almost no data on the colonization of rehabilitation patients with multiresistant gram-negative rods is available. Here we report on a large multicenter study on the prevalence of MRSA and multiresistant pathogens in rehabilitation institutions in the Rhine-Main area in 2014. Materials and Methods: Altogether, 21 rehabilitation hospitals participated. For all patients, age, gender, previous history of hospitalizations, surgery, previous colonization with multidrug-resistant organisms, use of a medical device, current antimicrobial therapy, and the current infection status were ascertained. On voluntary basis, nare and throat swabs were taken for analysis of MRSA and rectal swabs were tested for extended spectrum betalactamase-producing gram-negative bacteria (ESBL). Results: 50% of 2 440 patients had a history of hospitalization within the previous 6 months while 39% had undergone surgery during the past 30 days. Approximately a quarter of the patients had been transferred to a rehabilitation hospital directly from an acute care hospital, had been under antimicrobial therapy with the past three months, or had travelled to a foreign country within the previous year. Risk factors such as lesions of the intact skin or presence of medical devices were rarely reported (< 5%) within the exception of patients undergoing geriatric or neurologic acute care rehabilitation. 0.7% (15/2155) of the patients were colonized with MRSA, while 7.7% (110/1434) showed a positive result for ESBL. The highest prevalence rates for multiresistant organisms were encountered among patients with neurologic rehabilitation (MRSA, 1.3%, and ESBL, 10.2%) or with geriatric rehabilitation (MRSA, 9.4%, and ESBL, 22.7%). Conclusion: In the rehabilitation patient population, the prevalence rates of MRSA and ESBL were found to be in the range of rates encountered in the general population (reported rates for MRSA, 0.5%, and ESBL, 6.3%). The known risk factors for MRSA such as skin lesions, medical devices and previous history for MRSA were also confirmed among this patient population. Direct transfer from an acute care hospital, antimicrobial treatment during the past 3 months, and wounds proved significant risk factors for ESBL colonization. Patients of neurologic rehabilitation and geriatric patients showed the highest rates of risk factors and the highest prevalence rates of multidrug-resistant organisms. It appears to be of importance for rehabilitation hospitals to be geared to the needs of patients with multidrug-resistant organisms, and prevent the transmission of these pathogens by appropriate hygiene measures. © Georg Thieme Verlag KG Stuttgart, New York.
Arndt T.,Institute fur Medizinische Diagnostik GmbH |
Claussen U.,Therapeutische Einrichtung Auf der Lenzwiese |
Gussregen B.,Institute fur Medizinische Diagnostik GmbH |
Schrofel S.,Institute fur Medizinische Diagnostik GmbH |
And 3 more authors.
Forensic Science International | Year: 2011
Aim: A drug and alcohol withdrawal rehabilitation centre requested an analysis for "Krypton" in urine of a former opiate-addictive woman. She showed an altered clinical picture and behaviour with miosis, itchiness, agitation, and moderate euphoria after 3 months of until than successful treatment. Literature search revealed that "Krypton" is said to contain "Kratom" (leaves of Mitragyna speciosa), but could also contain O-desmethyltramadol (European Monitoring Centre for Drugs and Drug Addiction thematic paper "Spice"). Methods: Immunological drug screenings were done with test strips (nal von minden, Regensburg, Germany) and with cloned enzyme donor immunoassay (Microgenics, Passau, Germany). "Kratom" alkaloids and tramadol (metabolites) were analyzed by LC-MS/MS (ThermoFisher Scientific Quantum Ultra Triple Quadrupole mass spectrometer). Results: Immunoassays were negative for amphetamines, barbiturates, benzodiazepines, benzoylecgonine, buprenorphine, ethylglucuronide, methadone (metabolite), opiates, oxycodone, and THC-COOH, and test strips were negative for tramadol and its metabolites (cut-off 10 mg/L for O-desmethyltramadol). LC-MS/MS detected the "Kratom" alkaloids mitragynine, speciociliatine, speciogynine, mitraciliatine, and paynantheine and approximately 9 mg/L O-desmethyltramadol, but no tramadol and N-desmethyltramadol. Discussion: The detection of M. speciosa alkaloids is a proof of "Kratom" abuse. Confronted with the analysis data, the patient admitted to have consumed 3-4 infusions of "Krypton" The origin of the O-desmethyltramadol is unclear. Tramadol abuse is unlikely since tramadol and N-desmethyltramadol (physiologically occurring in urine after tramadol intake) were not detectable. Consumption of a "Krypton" product spiked with O-desmethyltramadol could explain our findings and the patient's clinical picture. This would be in agreement with a most recent report about spiking apparently natural herbal mixtures with the synthetic opioid O-desmethyltramadol. Conclusion: Analysis of "Kratom" abuse should not be restricted to M. speciosa alkaloids, but should also consider synthetic drugs which could be added to the herbal mixtures. Mass spectrometry based drug screenings will gain importance to keep pace with the dynamic drug market. © 2010 Elsevier Ireland Ltd.
Multidrug-Resistant Organisms (MDRO) in Rehabilitation Clinics in the Rhine-Main District, Germany, 2014: Risk Analysis and Hygiene Procedures [Multiresistente Erreger in Rehabilitationseinrichtungen im Rhein-Main-Gebiet, Deutschland, 2014: II. Ärztliche Risikoanalyse und Hygienemaβnahmen]
Heudorf U.,MRE Netz Rhein Main Gesundheitsamt Frankfurt A. M. |
Farber D.,MRE Netz Rhein Main Gesundheitsamt Frankfurt A. M. |
Mischler D.,MRE Netz Rhein Main Gesundheitsamt Frankfurt A. M. |
Schade M.,MRE Netz Rhein Main Gesundheitsamt Frankfurt A. M. |
And 3 more authors.
Rehabilitation (Germany) | Year: 2015
Background: Many regional German MDRO-networks aim to improve the medical rehabilitation of patients with methicillin-resistant Staphylococcus aureus (MRSA) and other multidrug-resistant pathogens. In 2014, the German Commission for Hospital Hygiene and Infection Control (KRINKO) released revised recommendations for the care of patients with MRSA. In particular, for rehabilitation facilities, these recommendations stipulated a medical risk analysis to establish necessary hygiene measures, and provide specific recommendations. Material and Methods: Based on a large investigation carried out in 21 rehabilitation facilities covering different medical specialties, medical risk analyses according to KRINKO were performed, and the findings evaluated separately for orthopedic, cardiologic, oncologic, neurologic, or geriatric facilities, as well as for all institutions taken together. Results: The overall colonization pressure, i. e. the point prevalence of MRSA and extended spectrum beta-lactamase-producing gram-negative pathogens (ESBL) among hospitalized rehabilitation patients was found to be 0.7% and 7.7%, respectively. Impairment of the intact skin (an established risk factor for persisting MRSA colonization and MRSA infection) was found in 7% of the patients, impaired mobility requiring enhanced level of care in 4.1%, and mental confusion and/or incontinence (potentially impairing the application of hygiene measures) in 11% of patients. Compared to the total study population, there was an increase in all risk factors in geriatric and neurologic rehabilitation patients: skin barrier breaches (in neurologic and in geriatric patients: 18.3 and 19.2%, respectively), impaired mobility (32.7 and 37.0%, respectively), and mental confusion/incontinence (24.5 and 28.0%, respectively). In addition, geriatric patients demonstrated an increased overall prevalence of multidrug-resistant organisms (MRSA: 9.4%; ESBL: 22.7%). Discussion: Risk analysis according to KRINKO showed that in rehabilitation facilities with internal medicine or orthopedics specialties, there was a comparably lower risk for transmission, colonization, and/or infection with multidrug-resistant pathogens, as against institutions with neurologic or geriatric specialty. It appears that in the first type of rehabilitation facilities, consistently carried out basic hygiene measures are sufficient while in neurologic or geriatric rehabilitation hospitals, these measures should be supplemented with additional hygiene measures based on medical risk analysis. Furthermore, for infection control purposes in rehabilitation facilities, patient isolation will be rarely necessary or appropriate. These analyses suggest that in the future, rehabilitation programs for MRSA/ESBL-colonized patients will be more successful. © Georg Thieme Verlag KG Stuttgart New York.