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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Why do different bacteria have different shapes?

Why do different bacteria have different shapes? Is it only related to their function?
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Why do 6-8% of diphtheria patients do not develop natural immunity after being affected?

I am thinking of why some patients do not have natural immunity after exposure to the A-B toxin of diphthria. I think the A-B exotoxin is the key factor causing this disease and should trigger memory ...
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49 views

Do bacteria with capsular antigen always have a capsule?

Assume some bacteria have capsular antigen. Do these bacteria always have a capsule? I think not, I think the antigen only makes it possible.
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767 views

Why do kefir grains stop growing in soy milk?

Kefir is a fermented milk drink made with kefir grains. It usually is prepared by inoculating cow, goat or sheep milk with kefir grains. I would like to prepare the drink with soy milk, which worked ...
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60 views

When might an inhibitor of bacterial transformation be useful?

I am part of a project elucidating some structures that are required for bacterial transformation. We have the opportunity to screen inhibitors of the system to stop it from functioning. I am not a ...
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159 views

How do I measure bacterial growth in agar dishes (either by cell mass or by cell count)?

I am doing an experiment in which I am growing S. mutans in agar dishes, and I am not sure how I would measure the growth of the S. mutans. I am also not sure if I would do this by measuring cell mass ...
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189 views

Factor causing Methicilin-resistance in MRSA?

I think the main reason is the natural selection that is causing methicillin-resistance. However, I am not completely sure what this means practically. Here, the original question: MRSA was isolated ...
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300 views

Is it possible for a person to become “reinfected” with the same strain of a virus?

If a person contracts a virus, viral conjunctivitis for example, is it possible for the individual to become "reinfected" with the exact same strain of the virus once the person has it treated and the ...
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125 views

What molecular processes are involved in pseudopodial extension?

I am curious as to the processes and mechanisms involved in the extension of pseudopodia in amoeba. How does the cell know and control the direction and extent of pseudopodia formation at a molecular ...
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430 views

“Acellular” designation for organisms

Why do some biologists refer to single-celled organisms such as Amoeba and Paramecium as acellular (i.e., without cells) rather than unicellular (i.e., one cell)?
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132 views

By what mechanism is Streptococcus bovis acting as a risk factor for colorectal cancer?

Streptococcus bovis bacteremia/endocarditis is considered a risk factor for colorectal cancer. What pathophysiological mechanism may link the two together?
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89 views

Highly spherical Radiolaria; does this image accurately depict the organism?

If I understand correctly, Cenosphaera spp. is a type of Radiolaria, which is a type of zooplankton. The following is an image of Cenosphaera spp. is from the supplementary material (Figure S2) of ...
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210 views

Can Naegleria fowleri enter through the eyes ( example rinsing/splashing eyes with water)

I understand that it primarily enters the body through the nose by by "feeding on the olfactory neurons in the nose" as answered here in a different question. Would the nerve cells in the eyes present ...
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214 views

Short-term Lamarckism in asexual single cell organisms

I was reading through the Karr et al. (2012) whole-cell computational model. One of the things they did was to induce single-gene disruptions in their model. They observed several to be fatal, but: ...
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59 views

For people who work in microbiology labs, what software do you use to manage your strains?

It's just a small microbiology lab that currently records everything on paper, and there's quite few mutants as well. Is Excel commonly used for this sort of thing? Or is there a better software to ...
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91 views

Can someone explain the color-changing unit (CCU) to me?

I've been physically carrying out serial tenfold dilutions on samples of Ureaplasma to work out the color-changing units (CCU). As a definition, the CCU is the highest dilution at which there is a ...
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148 views

What is the effect of garlic on intestinal flora?

Now that we can compare whole microbiomes, has there been investigations on the effect of garlic (or diallyl disulfide, its main ingredient) on intestinal flora? From the proven antimicrobial ...
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65 views

Can Listeria monocytogenes endotoxin act as an A-B toxin?

I think no, but I am not sure since Listeria is Gram-positive and probably has lipopolysaccharide (exception among Gram positive bacteria). Can Listeria monocytogenes' endotoxin act like exotoxin ...
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154 views

What type of photosynthesis is performed by phytoplankton?

I am not a biologist, but I know there exist three variants of photosynthesis, namely C3, C4 and CAM. I would like to know what type is used by the ocean's phytoplankton? It might also be that ...
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118 views

How to learn biomathematics?

I'm currently an undergraduate math student and researching on the internet I discover that exists an area called "biomathematics". Looks so interesting. They use the graph theory and topology to ...
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157 views

Where would Saccharomyces cerevisiae be found in highest concentrations in environment?

I have bakers asthma specifically to Sc yeast, and know to avoid bakeries, breweries, etc. Have figured out to not disturb rotting leaf piles, and fermenting bark mulch. Where else.? What percentage ...
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53 views

observed luminescence in a piece of plaice

A plaice fish bought for human feed has been cleaned and cooked. Some parts of the raw body have been left out of the fridge at about 22°C for about 15 hours. During the following night a ...
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67 views

Why does the mixture of infant formula with saliva provide an ideal breeding ground for disease-causing micro-organisms?

From: http://www.nal.usda.gov/wicworks/Topics/FG/Chapter4_InfantFormulaFeeding.pdf Discard any infant formula remaining after a feeding. The mixture of infant formula with saliva provides an ideal ...
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38 views

How can a respiratory infection lead to a skin infection?

Example of a case: 5 children develop a bright red rash on the face and turns violet after a few days and then disappears. Then maculopapular rash appears on the trunk, buttocks and extremities. It ...
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46 views

Salvaging a plasmid from a cell culture stored at the incorrect temperature

I have E. coli with transformed plasmid on agar in a vial. It has been stored at -20 degree C without glycerol stock for 18 hours. This is a continuation of: Survival of E. coli on agar plate at -20 ...
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41 views

What kind of a microscope do I need to see cell organelles?

I would like to study cells and looking for a microscope that would allow me to see: groups of cells individual cell cells organelles I would like to target insects and mammal tissue. I would be ...
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28 views

Which strains of C. diphteria are causing Diphteria toxin?

I got this question: Diphteria toxin is produced only by those strains of C. diphtheria that have which of the following characteristics? Encapsulated glucose fermenters lysogenic for b-prophage ...
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86 views

E. coli, risk of infection?

There has been a warning about E. coli contaminated water in South Florida. Now I'm wondering are there empirical data or historic cases which show a correlation between E.coli levels in tap water and ...
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277 views

How was the diversity between ethanol fermentation and lactic acid fermentation evolved?

Quite simply, some organisms metabolize glucose under anaerobic conditions via Glucose->(2) Pyruvic Acid->(2)Ethyl Alcohol. Some organisms, however, metabolize to lactic acid. When did such a process ...
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21 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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14 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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68 views

Aerobe or facultative anaerobe organism that metabolizes acetate?

I'm assuming bacteria, but will take any suggestions. Organism must survive primarily on the acetate (plus trace elements), but I can give/take electrons, if necessary. Not interested in strict ...
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116 views

Image Processing Suite for bacterial microscopy: Schnitzcells or MicrobeTracker?

I am looking to start doing some work tracking the size and growth of individual bacterial cells in the microscope. In order to analyze the images I need software that can segment the cells, ...
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35 views

Shortest route for a Nitrogen atom from fossil fuel to a protein in your body?

Millions of years ago fossil fuels originated from plants. A nitrogen atom from fossil fuel is now inside in a protein molecule in your body. What is the shortest path that the nitrogen atom ...
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37 views

Why do fresh cavities form from the margins of sliver amalgam fillings on teeth?

Silver amalgam fillings predominantly contain silver a known bactericidal agent and mercury which a known toxin and has bactericidal property. So how is it that the plaque bacteria survive near the ...
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26 views

Elevated transaminases after blood transfusion?

This sparks HCV immediately in my mind. However, there may be other possibilities too. What can you deduce from elevated transaminases if you only know that the healthy adult patient received blood ...
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39 views

Endophytic Xylariaceae: diversity and taxonomy inferred from rDNA sequence analyses

"Thailand is considered as one of the areas containing a high percentage of unknown taxa of Xylariaceae (Rogers 2000). In Thailand, several studies on endophytic fungi have been documented, namely, ...
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How is the appropriately-stratified gut microbiome acquired in organisms performing horizontal transmission?

I am studying horizontal transmission of primary symbionts in insect reproduction. This reminded me of an earlier question I had asked, in which I learned that humans analogously acquired their ...
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149 views

How to obtain bacteria samples?

Would anyone know how to go about obtaining samples of Salmonella or E. coli for purely educational purposes? Note: I just want to look at the stuff under a microscope.
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120 views

List of all reported bacteria

I would like to know were to download a table file with all reported bacteria and its corresponding PHYLUM, CLASS, ORDER and FAMILY. Basically, its the same table than this one from GOLD genomes but ...
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683 views

What are the differences between G+ and G- bacteria?

The distinction between Gram-positive and Gram-negative bacteria is based upon the Gram staining method, that reflects the bacterial wall physical properties. However, this classification involves ...
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14 views

Do Yersinia genus spp have anything movement factors?

It can spread in blood (Type III secretion system -> apoptosis). I am interested if there is any others ways to move. Do Yersinia spp have anything virulence factors to move?
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24 views

Staphylococcus AG structure?

I found this statement in my study materials in the section of Staphylococcus The AG structure: protein AG (species specific); polysaccharide AG (serotype specific). I know what is ...
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249 views

Can Naegleria fowleri enter through your ear?

Is it possible to get infected with the amoeba, Naegleria fowleri, through your ears, or is the nose the only way it can enter to cause infection? How commonly is it found in your stool as well?
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101 views

Lineage selection in plasmid evolution

I've been reading through Paulsson (2002) and I am not sure what he means by "lineage selection" in the second to last section. The paper deals with plasmid replication, and mostly concentrates on the ...
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172 views

Would two species of yeast with similar genome sizes have the same number of genes or chromosomes?

Similar organisms generally have similar genome sizes. Given this, would two species of yeast have the same number of genes and chromosomes? Edit: Fixed with thanks to @daniel-standage
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39 views

How do Gram + bacteria use a proton gradient for F-type ATPase?

Does anyone know of any papers showing how Gram positive Fermiculates or Actinobacteria use a H+ gradient for an F-type ATPase, It seems impossible since there is no outer LPS membrane to maintain ...
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19 views

Difference between Fulminant and Acute Meningococcemias

Fulminant seems to mead rapid. There is however some articles with both phrases: "fulminant meningococcecemia" (about 5000 Google matches) and "acute meningococcecemia" (about 3000 Google matches). I ...
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39 views

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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Why HIV patients have greater virulence of M.tuberculosis?

I am reading Murray Microbiology book. Some facts M. tuberculosis is an intracellular pathogen. At the time of exposure, M. tuberculosis enters the respiratory airways and infectious particles ...