279 research outputs found
Gut microbiota related to Giardia duodenalis, Entamoeba spp. and Blastocystis hominis infections in humans from Côte d'Ivoire.
INTRODUCTION:
Literature data provide little information about protozoa infections and gut microbiota compositional shifts in humans. This preliminary study aimed to describe the fecal bacterial community composition of people from Côte d'Ivoire harboring Giardia duodenalis, Entamoeba spp., and Blastocystis hominis, in trying to discover possible alterations in their fecal microbiota structure related to the presence of such parasites.
METHODOLOGY:
Twenty fecal samples were collected from people inhabiting three different localities of Côte d'Ivoire for copromicroscopic analysis and molecular identification of G. duodenalis, Entamoeba spp., and B. hominis. Temporal temperature gradient gel electrophoresis (TTGE) was used to obtain a fingerprint of the overall bacterial community; quantitative polymerase chain reaction (qPCR) was used to define the relative abundances of selected bacterial species/group, and multivariate statistical analyses were employed to correlate all data.
RESULTS:
Cluster analysis revealed a significant separation of TTGE profiles into four clusters (p < 0.0001), with a marked difference for G. duodenalis-positive samples in relation to the others (p = 5.4×10-6). Interestingly, qPCR data showed how G. duodenalis-positive samples were related to a dysbiotic condition that favors potentially harmful species (such as Escherichia coli), while Entamoeba spp./B. hominis-positive subjects were linked to a eubiotic condition, as shown by a significantly higher Faecalibacterium prausnitzii-Escherichia coli ratio.
CONCLUSIONS:
This preliminary investigation demonstrates a differential fecal microbiota structure in subjects infected with G. duodenalis or Entamoeba spp./B. hominis, paving the way for using further next-generation DNA technologies to better understand host-parasite-bacteria interactions, aimed at identifying potential indicators of microbiota changes
A bacterial ratchet motor
Self-propelling bacteria are a dream of nano-technology. These unicellular
organisms are not just capable of living and reproducing, but they can swim
very efficiently, sense the environment and look for food, all packaged in a
body measuring a few microns. Before such perfect machines could be
artificially assembled, researchers are beginning to explore new ways to
harness bacteria as propelling units for micro-devices. Proposed strategies
require the careful task of aligning and binding bacterial cells on synthetic
surfaces in order to have them work cooperatively. Here we show that asymmetric
micro-gears can spontaneously rotate when immersed in an active bacterial bath.
The propulsion mechanism is provided by the self assembly of motile Escherichia
coli cells along the saw-toothed boundaries of a nano-fabricated rotor. Our
results highlight the technological implications of active matter's ability to
overcome the restrictions imposed by the second law of thermodynamics on
equilibrium passive fluids.Comment: 4 pages, 3 figure
Eubiosis and dysbiosis: the two sides of the microbiota
The microbial ecosystem of the gastrointestinal tract is characterized by a great number of microbial species living in balance by adopting mutualistic strategies. The eubiosis/dysbiosis condition of the gut microbiota strongly influences our healthy and disease status. This review briefly describes microbiota composition and functions, to then focus on eubiosis and dysbiosis status: the two sides of the microbiot
Gut microbiota related to Giardia duodenalis, Entamoeba spp. and Blastocystis hominis infections in humans from Côte d'Ivoire
Introduction: Literature data provide little information about protozoa infections and gut microbiota compositional shifts in humans. This
preliminary study aimed to describe the fecal bacterial community composition of people from Côte d’Ivoire harboring Giardia duodenalis,
Entamoeba spp., and Blastocystis hominis, in trying to discover possible alterations in their fecal microbiota structure related to the presence
of such parasites.
Methodology: Twenty fecal samples were collected from people inhabiting three different localities of Côte d’Ivoire for copromicroscopic
analysis and molecular identification of G. duodenalis, Entamoeba spp., and B. hominis. Temporal temperature gradient gel electrophoresis
(TTGE) was used to obtain a fingerprint of the overall bacterial community; quantitative polymerase chain reaction (qPCR) was used to define
the relative abundances of selected bacterial species/group, and multivariate statistical analyses were employed to correlate all data.
Results: Cluster analysis revealed a significant separation of TTGE profiles into four clusters (p < 0.0001), with a marked difference for G.
duodenalis-positive samples in relation to the others (p = 5.4×10-6
). Interestingly, qPCR data showed how G. duodenalis-positive samples were
related to a dysbiotic condition that favors potentially harmful species (such as Escherichia coli), while Entamoeba spp./B. hominis-positive
subjects were linked to a eubiotic condition, as shown by a significantly higher Faecalibacterium prausnitzii-Escherichia coli ratio.
Conclusions: This preliminary investigation demonstrates a differential fecal microbiota structure in subjects infected with G. duodenalis or
Entamoeba spp./B. hominis, paving the way for using further next-generation DNA technologies to better understand host-parasite-bacteria
interactions, aimed at identifying potential indicators of microbiota changes
Swimming and rafting of E.coli microcolonies at air–liquid interfaces
The dynamics of swimming microorganisms is strongly affected by solid-liquid and air-liquid interfaces. In this paper, we characterize the motion of both single bacteria and microcolonies at an air-liquid interface. Both of them follow circular trajectories. Single bacteria preferentially show a counter-clockwise motion, in agreement with previous experimental and theoretical findings. Instead, no preferential rotation direction is observed for microcolonies suggesting that their motion is due to a different physical mechanism. We propose a simple mechanical model where the microcolonies move like rafts constrained to the air-liquid interface. Finally, we observed that the microcolony growth is due to the aggregation of colliding single-swimmers, suggesting that the microcolony formation resembles a condensation process where the first nucleus originates by the collision between two single-swimmers. Implications of microcolony splitting and aggregation on biofilm growth and dispersion at air-liquid interface are discussed
Serum albumin and osmolality inhibit Bdellovibrio bacteriovorus predation in human serum
We evaluated the bactericidal activity of Bdellovibrio bacteriovorus, strain HD100, within blood sera against bacterial strains commonly associated with bacteremic infections, including E. coli, Klebsiella pneumoniae and Salmonella enterica. Tests show that B. bacteriovorus HD100 is not susceptible to serum complement or its bactericidal activity. After a two hour exposure to human sera, the prey populations decreased 15- to 7,300-fold due to the serum complement activity while, in contrast, the B. bacteriovorus HD100 population showed a loss of only 33%. Dot blot analyses showed that this is not due to the absence of antibodies against this predator. Predation in human serum was inhibited, though, by both the osmolality and serum albumin. The activity of B. bacteriovorus HD100 showed a sharp transition between 200 and 250 mOsm/kg, and was progressively reduced as the osmolality increased. Serum albumin also acted to inhibit predation by binding to and coating the predatory cells. This was confirmed via dot blot analyses and confocal microscopy. The results from both the osmolality and serum albumin tests were incorporated into a numerical model describing bacterial predation of pathogens. In conclusion, both of these factors inhibit predation and, as such, they limit its effectiveness against pathogenic prey located within sera
Case Report: Safety and Efficacy of Tocilizumab in a Patient with Rheumatoid Arthritis and Chronic Hepatitis C
Tocilizumab is a monoclonal humanized anti-IL-6-receptor antibody used for the treatment of rheumatoid arthritis. The safety of tocilizumab in HCV patients is an open question. We report on safety and efficacy of tocilizumab in a 71-year-old female with rheumatoid arthritis and chronic hepatitis C. Monotherapy with tocilizumab (8 mg/kg every 4 weeks, i.v.) was prescribed after the discontinuation, determined by clinical inefficacy, of anti-TNF-alfa agents (adalimumab and, subsequently, etanercept). We have registered an optimal and rapid clinical response to tocilizumab with early remission (SDAI <3.3 since 4 weeks). The safety was good with no adverse events and maintenance, during a six-month followup, of normal liver enzymes. These data suggest a good safety profile of tocilizumab in patients with rheumatoid arthritis and chronic hepatitis C virus pathology
Місце адміністративної юстиції в системі права України
Стаття присвячена питанням місця норм, що регулюють порядок діяльності адміністративних судів в Україні, у національній системі права. Окрему увагу приділено проблемі існування адміністративного процесуального права та варіантам йог існування.Статья посвящена вопросам места норм, регулирующих порядок деятельности административных судов в Украине, в национальной системе права. Отдельное внимание уделено проблеме существования административного процессуального права и вариантам его существования.Article is devoted to substantiation of the place of norms, regulating the order of activity of administrative courts in Ukraine in the national system of law. Separate attention is given to the problem of existence of administrative process law and variants of it's existence
Investigating the Responses of Human Epithelial Cells to Predatory Bacteria
One beguiling alternative to antibiotics for treating multi-drug resistant infections are Bdellovibrio-and-like-organisms (BALOs), predatory bacteria known to attack human pathogens. Consequently, in this study, the responses from four cell lines (three human and one mouse) were characterized during an exposure to different predatory bacteria, Bdellovibrio bacteriovorus HD100, Bacteriovorus BY1 and Bacteriovorax stolpii EB1. TNF-alpha levels were induced in Raw 264.7 mouse macrophage cultures with each predator, but paled in comparison to those obtained with E. coli. This was true even though the latter strain was added at an 11.1-fold lower concentration (p < 0.01). Likewise, E. coli led to a significant (54%) loss in the Raw 264.7 murine macrophage viability while the predatory strains had no impact. Tests with various epithelial cells, including NuLi-1 airway, Caco2, HT29 and T84 colorectal cells, gave similar results, with E. coli inducing IL-8 production. The viabilities of the NuLi-1 and Caco-2 cells were slightly reduced (8%) when exposed to the predators, while T84 viability remained steady. In no cases did the predatory bacteria induce actin rearrangement. These results clearly demonstrate the gentle natures of predatory bacteria and their impacts on human cells.ope
Faecal microbiota composition is related to response to CDK4/6-inhibitors in metastatic breast cancer: A prospective cross-sectional exploratory study
Background: Cyclin-dependent kinase (CDK)4/6-inhibitors with endocrine therapy represent the standard of treatment of hormone receptor-positive(HR+)/human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC). Gut microbiota seems to predict treatment response in several tumour types, being directly implied in chemotherapy resistance and development of adverse effects. No evidence is available on gut microbiota impact on efficacy of HR+ breast cancer treatment. Patients and methods: We assessed the potential association among faecal microbiota and therapeutic efficacy of CDK4/6-inhibitors on 14 MBC patients classified as responders (R) and non-responders (NR) according to progression-free survival. A stool sample was collected at baseline and V3-V4 16S targeted sequencing was employed to assess its bacterial composition. Statistical associations with R and NR were studied. Results: No significant differences were observed between R and NR in terms of α-/β-diversity at the phylum and species level. Machine-learning (ML) algorithms evidenced four bacterial species as a discriminant for R (Bifidobacterium longum, Ruminococcus callidus) and NR (Clostridium innocuum, Schaalia odontolytica), and an area under curve (AUC) of 0.946 after Random Forest modelling. Network analysis evidenced two major clusters of bacterial species, named Species Interacting Groups (SIG)1-2, with SIG1 harbouring 75% of NR-related bacterial species, and SIG2 regrouping 76% of R-related species (p < 0.001). Cross-correlations among several patients' circulating immune cells or biomarkers and bacterial species' relative abundances showed associations with potential prognostic implications. Conclusions: Our results provide initial insights into the gut microbiota involvement in sensitivity and/or resistance to CDK4/6-inhibitors + endocrine therapy in MBC. If confirmed in larger trials, several microbiota manipulation strategies might be hypothesised to improve response to CDK4/6-inhibitors. Data availability statement: All raw data (fastq.gz files) and clinical metadata, complying with FAIR principles (https://www.go-fair.org/fair-principles/), are available at NCBI SRA portal under PRJNA946762 Bioproject
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