Microbiology is the study of organisms that are too small to be seen with the naked eye. This includes organisms like bacteria, fungi, protozoa, and others.

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How does activation of adenylcyclase lead to increased cAMP and diarrhea?

I am trying find explanation for these mechanisms Tox plasmid -> exotoxin (enterotoxin) -> activation of adenylcyclase -> \up cAMP enterocytes -> release of H2O, electrolytes in gut lumen -> ...
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69 views

Why does sulfonamid not inhibit the growth of Rickettsia?

Sulfonamid is an antimicrobial agent, why has it no effect on the growth of Rickettsia?
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110 views

explanation of conjugation experiment in bacteria

In this paper (On the expression of a structural gene) I am confused about what is being plotted in Figure 6. The x-axis contains the fraction of radioactive day and y-axis contains the enzyme ...
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54 views

Is this necrotizing skin infection caused by Staphylococcus aureus?

A 5-year-old boy returns from summer camp with several minor cuts and abrasions on legs. He has fever and extensive cellulitis, subcutaneous tissue and muscles are involved. Necrotic tissues were ...
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108 views

Is this case Histoplasma capsulatum?

A 62­ year-­old male was admitted to the hospital complaining of shortness of breath. His chest X­-ray showed a rightsided cavitary lesions. His medical history indicated he had smoked one pack of ...
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38 views

Do toxin producing strains of E. coli constantly produce toxin or only under certain conditions?

Background E. coli is prevalent everywhere but only some strains produce toxins harmful to humans, such as E. coli O157:H7. Questions 1) Would anyone know if these strains are always producing ...
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87 views

Colonial Cells Demonstrating Cell Specialization

Are there any living examples of cellular colonies demonstrating very primitive cellular specialization? If so, what do we know about how they assimilate? How independent are the individual cells ...
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413 views

Can the RNA in the HIV virus make viral enzymes without entering the nucleus?

If the provirus was not formed yet, can the virus make viral enzymes? (I know that it already has some, but supposing it doesn't)
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43 views

Optimization of E. coli growth in D₂O (heavy water)

I would like to find a method of increasing the biomass of my D2O cultures because my current method is not yielding enough protein. I would like to also minimize the amount of H2O in my culture. My ...
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52 views

Molecular Cloning- Blunt end restriction endonucleases

I work in a microbiology lab where we do a lot of cloning. I have always used restriction endonucleases to cleave the DNA to have sticky ends and not blunt ends. I currently am working on a project ...
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27 views

What is the specific use of a capsule in E.coli?

In evolutionary terms, will the capsule cease to exist someday or will it improve ? Does it provide any boost to the organism in any way which harms us ? Can't we remove capsules or engineer E.coli ...
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65 views

Science experiments at home with Minimal Cost

What is a good recipe for making agar at home for a minimal cost? Are there materials that could be found in the kitchen cabinet?
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65 views

How do penicillin resistant bacteria grow slower in the presence of penicillin?

We put 2 flasks inoculated with Bacillus cereus in 37⁰C: one with 100μg/ml penicillin + 50μg/ml chloramphenicol and the other without penicillin. We found that the OD is higher in the one without the ...
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37 views

Cells created using differently aligned proteins

I remember reading that scientist were making cells (I assume bacteria), that used differently oriented proteins to create a whole new class of life. Because apparently right and left aligned proteins ...
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129 views

Can SIRS occur without Sepsis from Infection?

I am thinking this figure It suggests me that there has to be Sepsis that infection can lead to SIRS. I am thinking particularly the pathogenesis of Cryptococcus neoformans where respiratory ...
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44 views

How does HBeAg change to Anti-HBe in acute hepatitis

I am thinking this figure which can also be drawn like this How does HBeAg change to Anti-HBe? There are some triggers that stimulate Anti-HBe production after HBeAg level is done. I think ...
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49 views

What's the fastest legal way for the nutrients in a dead body to re-enter the ecosystem?

Apologies for weirdness. Of the various legal methods of disposing of a human corpse, which one ensures the nutrients which compose the body get back into the wider ecosystem the fastest? Unless ...
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77 views

Can a fungus become resistant to a chemical such as Potassium Permanganate?

A friend used potassium permanganate solution to treat tinea on the hands/feet but after some initial success, the tinea seems to be making a comeback. Could the fungus develop resistance to potassium ...
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31 views

How host defends against S. pneumoniae capsule?

The host response involves at least phagocytosis and probably localised acute inflammatory response at least after the colonisation. I am thinking how the host can defend against pneumolysin which ...
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54 views

Why PPD test in patients without M.tuberculosis often slightly positive?

I got this question which I interpret as Why PPD test in patients without M. tuberculosis often have slightly positive PPD reaction i.e., a lifelong slightly positive skin test reaction? because ...
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63 views

Why bacteria produce light?

After seeing this video I am curious to know why the free living bacteria produce light. What advantage will they have ? Or is it just an "unintentional" result of one of their pathways ?
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44 views

Can germs develop surfactant resistance in a harmful way?

Germs can develop antimicrobial resistance. It is a problem serious enough to deserve an FAQ page on the WHO website (http://www.who.int/mediacentre/factsheets/fs194/en/). But how about surfactant ...
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90 views

How HIV Affects and Its Treatment using Combination Therapy

Can someone please help me with the following questions. I've written my specific questions right after the text question. Human immunodeficiency virus (HIV) is a retrovirus. Its genome is a single ...
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3answers
127 views

Assay for Beta-galactosidase activity in single cell microscopy

I'd like to be able to measure the activity of $\beta$-galactosidase in living cells with simple optical (maybe fluorescence) microscopy. Ideally I'd like to do a minimum of genetic engineering, and ...
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145 views

At what temperature does DNA re-anneal?

If primers weren't present in PCR at what temperature would DNA re-anneal? I am wondering how primers manage to bind on DNA strands before DNA manages to anneal back together.
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197 views

How to deduce if RNA virus infection or DNA virus infection

Is there any general rule to say this must be RNA virus infection and the other one DNA virus infection? Example of a case: 5 children develop a bright red rash on the face and turns violet after a ...
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89 views

Is iodised salt harmful to the lactofermentation process?

I was discussing sauerkraut recipes with someone on IRC a minute ago, and they warned me not to use iodised salt in the process. My first (and so far, the only successful) batch is one I made with ...
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3answers
3k views

Why do cell membranes have a lipid bilayer?

Many cells have a cell membrane composed of two layers of lipids, why is it two layers and not just one? What purpose do the membranes serve?
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51 views

“Oblong to Allantoids” … Is it valid?

I read on the text book: The characteristic of Dinemasporium are: superficial, cupulate to Discoid conidiomata with brown satae, Phialid conidiogenous cells that give rise to hyaline, oblong to ...
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225 views

What does “cellular” mean in this context?

I came across a confusing word when I was reading a Scientific American story, “Controversial Spewed Iron Experiment Succeeds as Carbon Sink” (by David Biello). It goes like this: “One key to the ...
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1k views

Is there a free alternative to Gelcompar for comparing banding patterns across multiple gels?

In order to run my microbial community samples from my experiments through DGGE, I was required to use multiple gels. Thus it is necessary to compare banding patterns across more than one gel. ...
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53 views

Growing E. coli at room temperature?

If I were to do a blue/white selection of transformed E. coli on LB agar ampicillin plates at room temperature (23⁰C) for about 2 days and 18 hours, will I run into the issue of satellite colonies or ...
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26 views

Effect of flask position in shaking incubator affects growth kinetics

During some cultivation experiments for my bachelor thesis I noticed that in liquid culture my bacteria (E. coli) grew differently, according to the position in the shaking incubator. Because the ...
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38 views

Alkaline Phosphatase

What is the predominant purpose of Alkaline Phosphatase in skeletal muscle fibers and liver cells. I know that it is a hydrolase enzyme that speeds up the degredation of proteins, lipids, starch and ...
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46 views

How do Streptococcus thermophilus and Lactobacillus bulgaricus precipitate the curd of swiss cheese?

I learned in my food microbiology class that Streptococcus thermophilus and Lactobacillus bulgaricus precipitate the curd of swiss cheese. However, I was wondering what type of mechanisms do these ...
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54 views

What is Mycoplasma Lyo medium?

Used for instance in this article The role of genital mycoplasmas as pathogens - - are generally neglected by diagnostic laboratories in the United Kingdom, possibly due to the lack of a ...
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44 views

Regulation of Cra protein level in E coli

Catabolite Activator/Repressor, Cra protein (formerly known as Fructure Repressor FruR) plays a significant role in central carbon metabolism of E coli. Its activity is inhibited by ...
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43 views

Vitamin D oral intake, transportation and absorption

Several factors affecting vitamin D and its active form absorption and storage acidity of stomach (not significant effect) cytopathic effects of viruses cytopathic effects of bacteria where the ...
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1answer
32 views

What are the best detection medias for cholera?

I heard this fact that you can use some [hypertriade] for vibrio cholera diagnosis which has compontents sucrose (yellow) mannose (yellow) arabinose (do not ferment; stay dark pink) I did not find ...
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23 views

How are lophotrichous flagella of helicobacter pylori produced?

I am thinking the mechanism is something like first adhesins (mucinase). Howevever, this does not seem to be enough. How are the flagella of H. pylori produced?
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56 views

What are current abiogenesis hypotheses for first food source?

What is the very first abiogenetic piece of reproducing life (small piece of RNA + ribosome that randomly occurred?) hypothesized to have used as an energy source? I'd be interested in sources to what ...
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1k views

Bacterial 16S rRNA PCR amplification with universal primers

I am doing an experiment to amplify the 16S rRNA gene from bacteria present in gut contents of fish. After extracting DNA, I perform one-step PCR with universal bacterial primers (27F, 1492R) and I ...
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61 views

What are the ingredients of Pheromone Trap using for controlling Fruit flies of cucumber?

Pheromone Traps are used for fruit fly control. But I have no idea which ingredients or chemicals are used for preparing Pheromone trap
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30 views

Improving throughput of CFU plating?

In a separate question I've described my general experimental setup where I need to measure the number of live cells in a growing bacterial culture in a fairly rapid and high-throughput manner. In ...
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39 views

What are the characteristic structures of bacillus M. tuberculosis and what they cause?

I answered to this question: In most forms of the disease, the bacillus M. tuberculosis spreads slowly and widely in the lungs, causing the formation of hard nodules (tubercles) in the ...
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42 views

Can viral proteins cause infection? [duplicate]

Possible Duplicate: HIV Rapid Tests Can proteins found on the surface of RNA viruses cause infection without the presence of the actual RNA and other components used in the virus?
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1answer
63 views

What does this sentence about toxemia and Clostridium tetani mean?

I know that Cl tetani is not invasive and strictly localised. I think toxemia means spread in the blood. I am thinking this sentence The volume of infected tissue is small, and the disease is ...
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20 views

S. pyogenes' skin infection diagnostics

S. pyogenes is "flesh-eating" bacteria. It results from life-theatening myonecrosis caused by this organism. S. pyogenes avoids phagocytosis (mediated primarily by capsule, M and M-like proteins, C5a ...
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2answers
87 views

What is the right spelling for this agar? [closed]

I could not spell the agar [gonoline-uroline] which I heard yesterday. My spelling is so wrong that I could not find it in Google. What is the right spelling for this agar?
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24 views

To understand clearly extraintestinal diseases

Extradistestinal disease seems to prefer to "bowel" diseases, I think this is about diseases outside gastrointestinal tract so stomach. Consider diseases ulcerative colitis and Crohn's disease ...