243 research outputs found

    Effect and feasibility of wearable physical activity trackers and pedometers for increasing physical activity and improving health outcomes in cancer survivors : A systematic review and meta-analysis

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    Purpose This systematic review and meta-analysis aimed to evaluate the effect of wearable devices for improving physical activity and health-related outcomes in cancer survivors. Methods CINAHL, Cochrane, Ebscohost, MEDLINE, Pubmed, ProQuest Health and Medical Complete, ProQuest Nursing and Allied Health Source, ScienceDirect, and SPORTDiscus databases were searched for randomized controlled trials published before September 1, 2020, that evaluated interventions involving wearable devices in cancer survivors. Standardized mean differences (SMDs) were calculated to assess effects on physical activity and health-related outcomes. Subgroup analyses were conducted to assess whether the effects differed by interventions and cancer characteristics. Risk of bias was assessed using the Cochrane risk of bias tool. Results Thirty-five trials were included (breast cancer, n = 15, 43%). Intervention durations ranged between 4 weeks and 1 year. Most trials (n = 25, 71%) involved pedometer-based physical activity interventions. Seven (20%) involved Fitbit-based interventions, and 3 (9%) involved other wearable physical activity trackers (e.g., Polar, Garmin). Compared to usual care, wearable devices had moderate-to-large effects (SMD range 0.54−0.87, p < 0.001) on moderate-intensity physical activity, moderate-to-vigorous-intensity physical activity, total physical activity, and daily steps. Compared to usual care, those in the intervention had higher quality of life, aerobic fitness, physical function, and reduced fatigue (SMD range = 0.18−0.66, all p < 0.05). Conclusion Wearable physical activity trackers and pedometers are effective tools that increase physical activity and improve health-related outcomes in individuals with cancer. Identifying how these devices can be implemented for longer-term use with other intervention components remains an area for future research. Graphical abstrac

    The Molecular Epidemiology of the Highly Virulent ST93 Australian Community Staphylococcus aureus Strain

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    In Australia the PVL - positive ST93-IV [2B], colloquially known as ‘‘Queensland CA-MRSA’’ has become the dominant CA-MRSA clone. First described in the early 2000s, ST93-IV [2B] is associated with skin and severe invasive infections including necrotizing pneumonia. A singleton by multilocus sequence typing (MLST) eBURST analysis ST93 is distinct from other S aureus clones. To determine if the increased prevalence of ST93-IV [2B] is due to the widespread transmission of a single strain of ST93-IV [2B] the genetic relatedness of 58 S. aureus ST93 isolated throughout Australia over an extended period were studied in detail using a variety of molecular methods including pulsed-field gel electrophoresis, spa typing, MLST, microarray DNA, SCCmec typing and dru typing. Identification of the phage harbouring the lukS-PV/lukF-PV Panton Valentine leucocidin genes, detection of allelic variations in lukS-PV/lukF-PV, and quantification of LukF-PV expression was also performed. Although ST93-IV [2B] is known to have an apparent enhanced clinical virulence, the isolates harboured few known virulence determinants. All PVL-positive isolates carried the PVL-encoding phage WSa2USA and the lukS-PV/lukF-PV genes had the same R variant SNP profile. The isolates produced similar expression levels of LukF-PV. Although multiple rearrangements of the spa sequence have occurred, the core genome in ST93 is very stable.The emergence of ST93-MRSA is due to independent acquisitions of different dru-defined type IV and type V SCCmec elements in several spa-defined ST93-MSSA backgrounds. Rearrangement of the spa sequence in ST93-MRSA has subsequently occurred in some of these strains. Although multiple ST93-MRSA strains were characterised, little genetic diversity was identified for most isolates, with PVLpositive ST93-IVa [2B]-t202-dt10 predominant across Australia. Whether ST93-IVa [2B] t202-dt10 arose from one PVL-positive ST93-MSSA-t202, or by independent acquisitions of SCCmec-IVa [2B]-dt10 into multiple PVL-positive ST93-MSSA-t202 strains is not known

    Significant variability exists in the cytotoxicity of global methicillin-resistant Staphylococcus aureus lineages.

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    Staphylococcus aureus is a major human pathogen where the emergence of antibiotic resistant lineages, such as methicillin-resistant S. aureus (MRSA), is a major health concern. While some MRSA lineages are restricted to the healthcare setting, the epidemiology of MRSA is changing globally, with the rise of specific lineages causing disease in healthy people in the community. In the past two decades, community-associated MRSA (CA-MRSA) has emerged as a clinically important and virulent pathogen associated with serious skin and soft-tissue infections (SSTI). These infections are primarily cytotoxin driven, leading to the suggestion that hypervirulent lineages/multi-locus sequence types (STs) exist. To examine this, we compared the cytotoxicity of 475 MRSA isolates representing five major MRSA STs (ST22, ST93, ST8, ST239 and ST36) by employing a monocyte-macrophage THP-1 cell line as a surrogate for measuring gross cytotoxicity. We demonstrate that while certain MRSA STs contain highly toxic isolates, there is such variability within lineages to suggest that this aspect of virulence should not be inferred from the genotype of any given isolate. Furthermore, by interrogating the accessory gene regulator (Agr) sequences in this collection we identified several Agr mutations that were associated with reduced cytotoxicity. Interestingly, the majority of isolates that were attenuated in cytotoxin production contained no mutations in the agr locus, indicating a role of other undefined genes in S. aureus toxin regulation

    Taking hospital pathogen surveillance to the next level

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    High-throughput bacterial genomic sequencing and subsequent analyses can produce large volumes of high-quality data rapidly. Advances in sequencing technology, with commensurate developments in bioinformatics, have increased the speed and efficiency with which it is possible to apply genomics to outbreak analysis and broader public health surveillance. This approach has been focused on targeted pathogenic taxa, such as Mycobacteria, and diseases corresponding to different modes of transmission, including food-and-water-borne diseases (FWDs) and sexually transmitted infections (STIs). In addition, major healthcare-associated pathogens such as methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci and carbapenemase-producing Klebsiella pneumoniae are the focus of research projects and initiatives to understand transmission dynamics and temporal trends on both local and global scales. Here, we discuss current and future public health priorities relating to genome-based surveillance of major healthcare-associated pathogens. We highlight the specific challenges for the surveillance of healthcare-associated infections (HAIs), and how recent technical advances might be deployed most effectively to mitigate the increasing public health burden they cause

    The Dominant Australian Community-Acquired Methicillin-Resistant Staphylococcus aureus Clone ST93-IV [2B] Is Highly Virulent and Genetically Distinct

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    Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) USA300 has spread rapidly across North America, and CA-MRSA is also increasing in Australia. However, the dominant Australian CA-MRSA strain, ST93-IV [2B] appears distantly related to USA300 despite strikingly similar clinical and epidemiological profiles. Here, we compared the virulence of a recent Australian ST93 isolate (JKD6159) to other MRSA, including USA300, and found that JKD6159 was the most virulent in a mouse skin infection model. We fully sequenced the genome of JKD6159 and confirmed that JKD6159 is a distinct clone with 7616 single nucleotide polymorphisms (SNPs) distinguishing this strain from all other S. aureus genomes. Despite its high virulence there were surprisingly few virulence determinants. However, genes encoding α-hemolysin, Panton-Valentine leukocidin (PVL) and α-type phenol soluble modulins were present. Genome comparisons revealed 32 additional CDS in JKD6159 but none appeared to encode new virulence factors, suggesting that this clone's enhanced pathogenicity could lie within subtler genome changes, such as SNPs within regulatory genes. To investigate the role of accessory genome elements in CA-MRSA epidemiology, we next sequenced three additional Australian non-ST93 CA-MRSA strains and compared them with JKD6159, 19 completed S. aureus genomes and 59 additional S. aureus genomes for which unassembled genome sequence data was publicly available (82 genomes in total). These comparisons showed that despite its distinctive genotype, JKD6159 and other CA-MRSA clones (including USA300) share a conserved repertoire of three notable accessory elements (SSCmecIV, PVL prophage, and pMW2). This study demonstrates that the genetically distinct ST93 CA-MRSA from Australia is highly virulent. Our comparisons of geographically and genetically diverse CA-MRSA genomes suggest that apparent convergent evolution in CA-MRSA may be better explained by the rapid dissemination of a highly conserved accessory genome from a common source

    Different bacterial gene expression patterns and attenuated host immune responses are associated with the evolution of low-level vancomycin resistance during persistent methicillin-resistant Staphylococcus aureus bacteraemia

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    BACKGROUND: Low-level vancomycin resistance in Staphylococcus aureus (vancomycin-intermediate S. aureus (VISA) and hetero-VISA [hVISA]) emerges during persistent infection and failed vancomycin therapy. Up-regulation of genes associated with the "cell wall stimulon" and mutations in the vraSR operon have both been implicated in the development of resistance, however the molecular mechanisms of resistance are not completely understood. To further elucidate the mechanisms leading to resistance transcriptome comparisons were performed using multiple clinical pairs of vancomycin-susceptible S. aureus (VSSA) and hVISA/VISA (n = 5), and three VSSA control pairs from hospitalized patients with persistent bacteraemia that did not develop hVISA/VISA. Based on the transcriptome results multiple genes were sequenced and innate immune system stimulation was assessed in the VSSA and hVISA/VISA pairs. RESULTS: Here we show that up-regulation of vraS and the "cell wall stimulon" is not essential for acquisition of low-level vancomycin resistance and that different transcriptional responses occur, even between closely related hVISA/VISA strains. DNA sequencing of vraSR, saeSR, mgrA, rot, and merR regulatory genes and upstream regions did not reveal any differences between VSSA and hVISA/VISA despite transcriptional changes suggesting mutations in these loci may be linked to resistance in these strains. Enhanced capsule production and reduced protein A expression in hVISA/VISA were confirmed by independent bioassays and fully supported the transcriptome data. None of these changes were observed in the three control pairs that remained vancomycin-susceptible during persistent bacteremia. In a macrophage model of infection the changes in cell surface structures in hVISA/VISA strains were associated with significantly reduced NF-kappaB activation resulting in reduced TNF-alpha and IL-1beta expression. CONCLUSION: We conclude that there are multiple pathways to low-level vancomycin resistance in S. aureus, even among closely related clinical strains, and these can result in an attenuated host immune response. The persistent infections associated with hVISA/VISA strains may be a consequence of changes in host pathogen interactions in addition to the reduced antibiotic susceptibility

    Key challenges for the surveillance of respiratory viruses: transitioning out of the acute phase of the SARS-CoV-2 pandemic

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    To support the ongoing management of viral respiratory diseases, many countries are moving towards an integrated model of surveillance for SARS-CoV-2, influenza, and other respiratory pathogens. While many surveillance approaches catalysed by the COVID-19 pandemic provide novel epidemiological insight, continuing them as implemented during the pandemic is unlikely to be feasible for non-emergency surveillance, and many have already been scaled back. Furthermore, given anticipated co-circulation of SARS-CoV-2 and influenza, surveillance activities in place prior to the pandemic require review and adjustment to ensure their ongoing value for public health. In this perspective, we highlight key challenges for the development of integrated models of surveillance. We discuss the relative strengths and limitations of different surveillance practices and studies, their contribution to epidemiological assessment, forecasting, and public health decision making

    Emergence and rapid global dissemination of CTX-M-15-associated Klebsiella pneumoniae strain ST307

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    Objectives: Recent reports indicate the emergence of a new carbapenemase-producing Klebsiella pneumoniae clone, ST307. We sought to better understand the global epidemiology and evolution of this clone and evaluate its association with antimicrobial resistance (AMR) genes. Methods: We collated information from the literature and public databases and performed a comparative analysis of 95 ST307 genomes (including 37 that were newly sequenced). Results: We show that ST307 emerged in the mid-1990s (nearly 20 years prior to its first report), is already globally distributed and is intimately associated with a conserved plasmid harbouring the blaCTX-M-15 ESBL gene and several other AMR determinants. Conclusions: Our findings support the need for enhanced surveillance of this widespread ESBL clone in which carbapenem resistance has occasionally emerged.publishedVersio
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