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Many gut microbes are pathobionts or opportunistic pathogens — these organisms can be part of the normal gut flora (microbiome) of healthy individuals, but under the right (for them) circumstances (e.g.s: when introduced into the bloodstream by a cut, or due to immunosuppression) they can cause disease.1,2 As for urine, there are many fewer microbes present ...


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Urine is contaminated with skin bacteria and possibly something excreted from your blood. A very tiny fraction of urine is microbial. Feces is basically a solid mass of undigested food, gut bacteria, and their byproducts. Many gut bacteria in particular have evolved in the conditions the human body produces so many can survive well in human tissue. about 30%...


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Clostridium tetani produces a protein toxin, tetanospasmin which causes the major symptom of tetanus, namely involuntary muscle spasms. C. tetani is an aerobic species, does not infect the blood, and apparently only produces toxin in anaerobic conditions. If a pathogenic bacterium propagates through the bloodstream this condition is referred to as ...


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The kidney is essentially a filter which extracts dissolved waste products & water from the blood. It basically allows only molecular-sized things to pass, otherwise it would continually leak blood cells. The digestive tract OTOH is basically a tube. Stuff gets mashed up at one end and ejected at the other. Even fairly large objects can pass through ...


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No, a thrombus would be much too large to pass through the highly selective blood brain barrier. However, there are some cases where intra-vascular thrombosis can cause stroke. One example would be non anti-coagulated atrial fibrillation, where the inefficient beating of the heart causes blood to remain stagnant in the left atrium. This can cause a ...


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This question seems to stem from a misunderstanding of the nature of the Blood-Brain-Barrier, the circulatory system of the brain and of thrombi. The BBB is describes differences in the structure of the walls of the blood vessels of the brain, it is not a barrier to flow within the vessel, but a specialized barrier to flow out of the vessel. In many tissues ...


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It is a well documented observation that Plasmodium (vivax and knowlesi) infection is dependent on the Duffy blood groups [1]. Individuals lacking the Duffy antigens (Fya and Fyb) have lower susceptibility to malaria. Plasmodium expressed Duffy Binding Proteins facilitate in establishing the initial contact between the merozoite and the RBCs. However, ...


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Streptococcus pneumoniae is a pathogenic species. Streptococcus pneumoniae R6 is an avirulent strain of this species. Presumably this means that specific virulence genes that are present in virulent strains of Streptococcus pneumoniae are missing or mutated in the R6 strain. In fact the most likely difference would be that virulence factors are encoded by a ...


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Because it is first important to understand a mechanism before you can think about using it for drugs. Take melanoma for example: A large subset of melanoma has a mutated and constitutive active BRAF kinase which permanently signals towards the nucleus and thus deregulates gene expression. Once this mutation was found it was possible to design inhibitors ...


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No, thrombi are far too bulky to cross the blood brain barrier. Now regarding the risk of stroke in case of systemic thrombi Yes, there are 2 situations where this can arise: floating thrombus of the great circulation proximal to the aortic arch (i.e. Most of the time, chronic atrial fibrillation) venous thrombus with an associated patent foramen ovale, ...


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M00115 is a pathway module (NAD biosynthesis) whereas M00542 is a signature module (EHEC/EPEC pathogenicity signature). From the KEGG page on modules: pathway modules – representing tight functional units in KEGG metabolic pathway maps, such as M00002 (Glycolysis, core module involving three-carbon compounds) signature modules – as markers of ...


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I can only speak to what I am familiar with, but I would assume that the large majority of those viruses are bacteriophages. These bacteriophages, or "phages" for short, are viruses that infect bacteria. I should mention that these phages are not human pathogens though. When we go out into the field to discover novel phages, we often go to wastewater ...


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There are two other, but rather exotic possibilites which explain why people do not develop immunity after an diphtheria infection. These are unlikely to get to 6-8% of the cases which @Masi writes, but I am missing the reference here. The first possibility are people with chronic renal failure. They have problems with their immune responses since their ...


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Low density lipoproteins can be taken up by the macrophages under a number of circumstances (typically high circulating levels is the most important). These macrophages are called foam cells. The macrophage can then die and deposit this cholesterol and fatty material onto a vessel wall in the context of atherosclerosis. Additionally tissue damage as a result ...


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Module means, as defined in the KEGG Module page, a functional unit. So it can be anything, from groups of enzymes to genes to metabolites. About the two that concerns you: Pathway modules represent groups of functionally related enzymes part of the metabolic network. I think this one is easy to understand because it represents the classical understanding ...


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The gut microbiome is extremely complicated, and almost anything related to it is only partially known, therefore prone to oversimplification. Trying to explain the phenomenon of gut fermentation syndrome in such a limited fashion (age, gender, ethnicity, quantity of one particular yeast, etc.) will not help us understand it. Common yeasts (C. albicans, C....


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Probably you used bad keywords. It is called cytokine (or interleukin) network what you are looking for. There are several articles in the topic. For example: Cytokine patterns during dengue shock syndrome Multiplex cytokine profile from dengue patients: MIP-1beta and IFN-gamma as predictive factors for severity You can find here more: https://scholar....


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From the abstract of the linked article (Guttman, 2002): We used an in vivo genetic screen to identify 13 effectors [...]. Although sharing little overall homology, the amino-terminal regions of these effectors had strikingly similar amino acid compositions. And from the body: The screen relied on the type III secretion signal and the endogenous ...


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This is an interesting an useful question about host-pathogen interactions. For a general reference (for both hosts with and without a competent CD4+ T-cell response) see Cecil Medicine, Ch.332, and Murray Medical Microbiology, Ch. 28. There is also a decent review in Lancet Infectious Disease that discusses the pathophysiology in immunocompromised hosts. ...


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As Canadianer already mentioned in the comments, the majority of bacteria (this includes gram-negative bacteria) are non-pathogenic. I think a prime example is the human gut flora. You can find loads of bacterial species living in your gut without doing you any harm, if anything they are doing you a favour by breaking down food. Here some examples of gram-...


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I have no idea how practical it would be for your intended application, but people do estimate airborne concentrations of fungi and bacteria by sampling aerosols (i.e., filtering a volume of area to extract dust etc. that can carry the target organisms) and then using quantitative PCR with primers targeted at generic fungal or bacterial DNA sequences to ...


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You want to go to PATRIC > Data > Download Tool. From the Taxonomy tree, find Vibrio cholerae, choose Type of annotation as either PATRIC/RefSeq or both, choose the type of file you want (gbk or faa) and download from there.


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Sticking my neck out (and expecting it to be bitten by a black swan) it appears that all the examples of toxins secreted by bacterial pathogens when they infect an animal host (exotoxins) are proteins. However fungi secrete a variety of exotic (and often very nasty) small non-protein molecules (mycotoxins). It’s not clear from the question whether you ...


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Theoretically there are two very basic things to consider in judging virulence for the secretion systems: a) Can it secrete into any human cell? (If not, chances of being virulent are smaller, but not zero as whatever is secreted in the environment of a cell could also be harmful for the cell.) b) Does it secrete some agent (protein, RNA, molecule), which ...


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I think you cannot find a better answer then the following review: http://www.nature.com/nrmicro/journal/v13/n6/full/nrmicro3456.html It was published in 2015, and it gives a good overview about the secretion systems. Anyway, T6SS can also be virulent. Vibrio cholerae can use an effector of this SS to cross-link actin in the host cell and modify its ...


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Virulence factors of V cholerae is regulated by a hierarchical regulatory system. The proteins you listed in your question are part of this system. In this paper it is said that the actual activation of TCP and CT is done by ToxT- thus this could be your "key" protein. I'd also like to note that just because these are two different genes does not necessarily ...


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If I may add to what Resonating has said, when it comes to infections, dry cough is usually associated with a viral infection, whereas wet cough is usually caused by bacteria. The two are treated very differently - dry cough is remedied with cough-supressing drugs (antivirals are rarely needed), whereas bacterial infections are medicated with antibiotics (...


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The mechanism is likely very straightforward. Activated macrophages already in the area are releasing pro-inflammatory cytokines like TNFα, IL-1β, IL-6, IL-12, MIP-2, etc. These are not only important for granuloma formation, but they also recruit other immune cells to the area. However, since cord factor has this anti-migratory effect, once the cells get ...


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As a note, the suffix -genesis refers to the development or production of something, while the suffix -osis can be roughly translated as '...a current state of...' something.


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I would say fibrosis represents an abnormal accumulation of fibrous tissue usually collagen fibres. Where as fibrogenesis is the process of formation of fibrous tissues be it collagen, reticulin, elastic, oxytalan..


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