1,452 research outputs found

    Widespread Detection of Yersiniabactin Gene Cluster and Its Encoding Integrative Conjugative Elements (ICE Kp) among Nonoutbreak OXA-48-Producing Klebsiella pneumoniae Clinical Isolates from Spain and the Netherlands.

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    In this study, we determined the presence of virulence factors in nonoutbreak, high-risk clones and other isolates belonging to less common sequence types associated with the spread of OXA-48-producing Klebsiella pneumoniae clinical isolates from The Netherlands (n = 61) and Spain (n = 53). Most isolates shared a chromosomally encoded core of virulence factors, including the enterobactin gene cluster, fimbrial fim and mrk gene clusters, and urea metabolism genes (ureAD). We observed a high diversity of K-Locus and K/O loci combinations, KL17 and KL24 (both 16%), and the O1/O2v1 locus (51%) being the most prevalent in our study. The most prevalent accessory virulence factor was the yersiniabactin gene cluster (66.7%). We found seven yersiniabactin lineages-ybt 9, ybt 10, ybt 13, ybt 14, ybt 16, ybt 17, and ybt 27-which were chromosomally embedded in seven integrative conjugative elements (ICEKp): ICEKp3, ICEKp4, ICEKp2, ICEKp5, ICEKp12, ICEKp10, and ICEKp22, respectively. Multidrug-resistant lineages-ST11, ST101, and ST405-were associated with ybt 10/ICEKp4, ybt 9/ICEKp3, and ybt 27/ICEKp22, respectively. The fimbrial adhesin kpi operon (kpiABCDEFG) was predominant among ST14, ST15, and ST405 isolates, as well as the ferric uptake system kfuABC, which was also predominant among ST101 isolates. No convergence of hypervirulence and resistance was observed in this collection of OXA-48-producing K. pneumoniae clinical isolates. Nevertheless, two isolates, ST133 and ST792, were positive for the genotoxin colibactin gene cluster (ICEKp10). In this study, the integrative conjugative element, ICEKp, was the major vehicle for yersiniabactin and colibactin gene clusters spreading. IMPORTANCE Convergence of multidrug resistance and hypervirulence in Klebsiella pneumoniae isolates has been reported mostly related to sporadic cases or small outbreaks. Nevertheless, little is known about the real prevalence of carbapenem-resistant hypervirulent K. pneumoniae since these two phenomena are often separately studied. In this study, we gathered information on the virulent content of nonoutbreak, high-risk clones (i.e., ST11, ST15, and ST405) and other less common STs associated with the spread of OXA-48-producing K. pneumoniae clinical isolates. The study of virulence content in nonoutbreak isolates can help us to expand information on the genomic landscape of virulence factors in K. pneumoniae population by identifying virulence markers and their mechanisms of spread. Surveillance should focus not only on antimicrobial resistance but also on virulence characteristics to avoid the spread of multidrug and (hyper)virulent K. pneumoniae that may cause untreatable and more severe infections

    Characterization of mobile genetic elements in multidrug-resistant Bacteroides fragilis isolates from different hospitals in the Netherlands

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    Objectives: Five human clinical multidrug-resistant (MDR) Bacteroides fragilis isolates, including resistance to meropenem and metronidazole, were recovered at different hospitals in the Netherlands between 2014 and 2020 and sent to the anaerobic reference laboratory for full characterization. Methods: Isolates were recovered from a variety of clinical specimens from patients with unrelated backgrounds. Long- and short-read sequencing was performed, followed by a hybrid assembly to study the presence of mobile genetic elements (MGEs) and antimicrobial resistance genes (ARGs). Results: A cfxA gene was present on a transposon (Tn) similar to Tn4555 in two isolates. In two isolates a novel Tn was present with the cfxA gene. Four isolates harbored a nimE gene, located on a pBFS01_2 plasmid. One isolate contained a novel plasmid carrying a nimA gene with IS1168. The tetQ gene was present on novel conjugative transposons (CTns) belonging to the CTnDOT family. Two isolates harbored a novel plasmid with tetQ. Other ARGs in these isolates, but not on an MGE, were: cfiA, ermF, mef(EN2), and sul2. ARGs harboured differed between isolates and corresponded with the observed phenotypic resistance. Conclusions: Novel CTns, Tns, and plasmids were encountered in the five MDR B. fragilis isolates, complementing our knowledge on MDR and horizontal gene transfer in anaerobic bacteria

    The Microbiome in Bronchial Biopsies from Smokers and Ex-Smokers with Stable COPD - A Metatranscriptomic Approach.

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    Current knowledge about the respiratory microbiome is mainly based on 16S ribosomal RNA gene sequencing. Newer sequencing approaches, such as metatranscriptomics, offer the technical ability to measure the viable microbiome response to environmental conditions such as smoking as well as to explore its functional role by investigating host-microbiome interactions. However, knowledge about its feasibility in respiratory microbiome research, especially in lung biopsies, is still very limited. RNA sequencing was performed in bronchial biopsies from clinically stable smokers (n = 5) and ex-smokers (n = 6) with COPD not using (inhaled) steroids. The Trinity assembler was used to assemble non-human reads in order to allow unbiased taxonomical and microbial transcriptional analyses. Subsequently, host-microbiome interactions were analyzed based on associations with host transcriptomic data. Ultra-low levels of microbial mass (0.009%) were identified in the RNA-seq data. Overall, no differences were identified in microbiome diversity or transcriptional profiles of microbial communities or individual microbes between COPD smokers and ex-smokers in the initial test dataset as well as a larger replication dataset. We identified an upregulated host gene set, related to the simultaneous presence of Bradyrhizobium, Roseomonas, Brevibacterium.spp., which were related to PERK-mediated unfolded protein response (UPR) and expression of the microRNA-155-5p. Our results show that metatranscriptomic profiling in bronchial biopsy samples from stable COPD patients yields ultra-low levels of microbial mass. Further, this study illustrates the potential of using transcriptional profiling of the host and microbiome to gain more insight into their interaction in the airways

    Associations between maternal psychological distress and mother-infant bonding: a systematic review and meta-analysis

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    Purpose: Maternal psychological distress and mother-infant bonding problems each predict poorer offspring outcomes. They are also related to each other, yet the extensive literature reporting their association has not been meta-analysed. Methods: We searched MEDLINE, PsycINFO, CINAHL, Embase, ProQuest DTG, and OATD for English-language peer-reviewed and grey literature reporting an association between mother-infant bonding, and multiple indicators of maternal psychological distress. Results: We included 133 studies representing 118 samples; 99 samples (110,968 mothers) were eligible for meta-analysis. Results showed concurrent associations across a range of timepoints during the first year postpartum, between bonding problems and depression (r = .27 [95% CI 0.20, 0.35] to r = .47 [95% CI 0.41, 0.53]), anxiety (r = .27 [95% CI 0.24, 0.31] to r = .39 [95% CI 0.15, 0.59]), and stress (r = .46 [95% CI 0.40, 0.52]). Associations between antenatal distress and subsequent postpartum bonding problems were mostly weaker and with wider confidence intervals: depression (r = .20 [95% CI 0.14, 0.50] to r = .25 [95% CI 0.64, 0.85]), anxiety (r = .16 [95% CI 0.10, 0.22]), and stress (r = .15 [95% CI − 0.67, 0.80]). Pre-conception depression and anxiety were associated with postpartum bonding problems (r = − 0.17 [95% CI − 0.22, − 0.11]). Conclusion: Maternal psychological distress is associated with postpartum mother-infant bonding problems. Co-occurrence of psychological distress and bonding problems is common, but should not be assumed. There may be benefit in augmenting existing perinatal screening programs with well-validated mother-infant bonding measures

    Longitudinal study of the short- and long-term effects of hospitalisation and oral trimethoprim-sulfadiazine administration on the equine faecal microbiome and resistome

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    Background: Hospitalisation and antimicrobial treatment are common in horses and significantly impact the intestinal microbiota. Antimicrobial treatment might also increase levels of resistant bacteria in faeces, which could spread to other ecological compartments, such as the environment, other animals and humans. In this study, we aimed to characterise the short- and long-term effects of transportation, hospitalisation and trimethoprim-sulfadiazine (TMS) administration on the faecal microbiota and resistome of healthy equids. Methods: In a longitudinal experimental study design, in which the ponies served as their own control, faecal samples were collected from six healthy Welsh ponies at the farm (D0–D13-1), immediately following transportation to the hospital (D13-2), during 7 days of hospitalisation without treatment (D14–D21), during 5 days of oral TMS treatment (D22–D26) and after discharge from the hospital up to 6 months later (D27–D211). After DNA extraction, 16S rRNA gene sequencing was performed on all samples. For resistome analysis, shotgun metagenomic sequencing was performed on selected samples. Results: Hospitalisation without antimicrobial treatment did not significantly affect microbiota composition. Oral TMS treatment reduced alpha-diversity significantly. Kiritimatiellaeota, Fibrobacteres and Verrucomicrobia significantly decreased in relative abundance, whereas Firmicutes increased. The faecal microbiota composition gradually recovered after discontinuation of TMS treatment and discharge from the hospital and, after 2 weeks, was more similar to pre-treatment composition than to composition during TMS treatment. Six months later, however, microbiota composition still differed significantly from that at the start of the study and Spirochaetes and Verrucomicrobia were less abundant. TMS administration led to a significant (up to 32-fold) and rapid increase in the relative abundance of resistance genes sul2, tetQ, ant6-1a, and aph(3”)-lb. lnuC significantly decreased directly after treatment. Resistance genes sul2 (15-fold) and tetQ (six-fold) remained significantly increased 6 months later. Conclusions: Oral treatment with TMS has a rapid and long-lasting effect on faecal microbiota composition and resistome, making the equine hindgut a reservoir and potential source of resistant bacteria posing a risk to animal and human health through transmission. These findings support the judicious use of antimicrobials to minimise long-term faecal presence, excretion and the spread of antimicrobial resistance in the environment. [MediaObject not available: see fulltext.]

    Gut enterochromaffin cells drive visceral pain and anxiety

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    Gastrointestinal (GI) discomfort is a hallmark of most gut disorders and represents an important component of chronic visceral pain1 . For the growing population aficted by irritable bowel syndrome, GI hypersensitivity and pain persist long after tissue injury has resolved2 . Irritable bowel syndrome also exhibits a strong sex bias, aficting women three times more than men1 . Here, we focus on enterochromafn (EC) cells, which are rare excitable, serotonergic neuroendocrine cells in the gut epithelium3–5 . EC cells detect and transduce noxious stimuli to nearby mucosal nerve endings3,6 but involvement of this signalling pathway in visceral pain and attendant sex diferences has not been assessed. By enhancing or suppressing EC cell function in vivo, we show that these cells are sufcient to elicit hypersensitivity to gut distension and necessary for the sensitizing actions of isovalerate, a bacterial short-chain fatty acid associated with GI infammation7,8 . Remarkably, prolonged EC cell activation produced persistent visceral hypersensitivity, even in the absence of an instigating inflammatory episode. Furthermore, perturbing EC cell activity promoted anxiety-like behaviours which normalized after blockade of serotonergic signalling. Sex diferences were noted across a range of paradigms, indicating that the EC cell–mucosal afferent circuit is tonically engaged in females. Our findings validate a critical role for EC cell–mucosal afferent signalling in acute and persistent GI pain, in addition to highlighting genetic models for studying visceral hypersensitivity and the sex bias of gut pain.James R. Bayrer, Joel Castro, Archana Venkataraman, Kouki K. Touhara, Nathan D. Rossen, Ryan D. Morrie, Jessica Maddern, Aenea Hendry, Kristina N. Braverman, Sonia Garcia-Caraballo, Gudrun Schober, Mariana Brizuela, Fernanda M. Castro Navarro, Carla Bueno-Silva, Holly A. Ingraham, Stuart M. Brierley, David Juliu
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