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14

Bacteria have a mesh-like structure surrounding their plasma membrane called a cell wall. The cell wall is made up of peptidoglycan polymers that form a rigid crystalline structure that helps protect the osmotic pressure of the bacterial cytoplasm. Penicillin and other β-lactams work by inhibiting the final step of peptidoglycan synthesis, which ...


9

There are a number of ways to address antibiotic resistance in infectious bacteria. What one gets used depends on exactly what organism we're talking about. But below is a short list of some ways: Changing the antibiotic being used. Not all antibiotics have the same molecular target within a bacterial cell. Some interfere with the formation of the cell ...


9

No. The CDC recommends using a hand sanitizer at at least 60% ethanol. Most preparations used in the lab are 70% ethanol. Humans start to risk death somewhere around the 0.3% alcohol level (BAC), especially around 0.5%. People have gone higher, but even 1% BAC would be completely useless against bacteria. You'd be dead long before the bacteria died. ...


8

In general antibiotics don't help with viruses. However, sometimes a bacterial infection may follow a cold virus, so there might be some scenarios in which antibiotics would be needed. However in many cases it could be due to people demanding antibiotics from their doctor. You can read more here (CDC site): http://www.cdc.gov/Features/getsmart/


8

An antibacterial is any compound that will kill or at least slow down the growth of strictly bacteria, a domain of prokaryotes. An antibiotic is often used synonymously, but denotes a compound that kills or slows down the growth of any cellular pathogen, prokaryotic or eukaryotic. So, certain antibiotics can kill bacteria, fungi and parasites but ...


7

This may be related to this question on Skeptics SE: Does regular handwashing with antibacterial soap prevent disease? Since it is closely related, I will copy my answer from there to here: See this related answer. To answer your specific questions: Has something changed? Well, we have access to these products now, whereas we didn't before. ...


6

A quick search on ISI Web of Knowledge yielded this paper: R J North, P A Berche and M F Newborg (1981) Immunologic consequences of antibiotic-induced abridgement of bacterial infection: effect on generation and loss of protective T cells and level of immunologic memory. Journal of Immunology 127: 342-346 The authors investigated the effects of ...


6

Why is NADH the first thing to come to mind? Time for some physical chemistry. Beta-lactams has a shorter ring structure which give it a different absorbance (around 322 nm apparently (source needed)) which gives it a blueish hue. Typically Penicillin and Ampicillin start off as an off-white. As hinted by @Mad Scientist, the beta-lactam rings are unstable ...


4

I thought I would attempt to answer my own question. The only other answer currently (by Larian LeQuella), while a helpful comment, I feel it doesn't answer my original question. To begin, we need to put the results into context. Fact: Hand-washing using tap water alone will reduce the amount of bacteria and viruses on hands (they might not be actually ...


4

What the comments are trying to say might go something like this. The antibiotic triclosan that's used in almost all 'antibacterial' products works pretty quickly - by interfering with several processes in the bacterial and fungal membrane. It doesn't need much more than contact to work. That being said, the longer your exposure to the antibiotic, the ...


3

First of all I find quorum sensing to be generally facinating, so I'm happy to see the topic brought up here. Dr. Bassler has many papers on the subject, but I think one of the most relevant ones to this question is here. Regarding your question, you have the right idea, but you're missing the point of her comment. The Western shows a more dramatic ...


3

Usually, resistance genes are located on plasmids---additional DNA rings in the bacterium that are part of the genome. These plasmids cause their own exchange with other bacteria, even from other species. B. clausii, the probiotics organism in question here, appears to be special, though, in that it has no plasmids. His resistance genes come with the ...


3

I have never heard about this phenomenon from my patients or professors at the Medical School, but this is a possible mechanism that comes to my mind. One of the classification for antibiotics takes consideration the effect on bacteria. Two possible effects are either stopping the proliferation (and letting the immune system to kill those that are currently ...


3

The short answer is, as you found, that mitochondria are wrapped in a double membrane and are thus harder to penetrate with antibiotics. The long answer is some of them do. Good antibiotics target structures widely found on and conserved in bacteria that are not found in human bodies. Some antibiotics are a little less specific and can indeed interact ...


3

From the Wikipedia article (I'm sure there's a scholarly reference, but I think this is well-known): Lactulose works by relieving constipation through a number of different methods. Lactulose is made up of sugar molecules and is partly broken down by the bacteria that live in the lower part of the gut. So, certain antibiotics affect (and reduce) the ...


2

I think your guess is quite spot-on. According to this scientific article I found online, They did a whole genome sequencing on penicillin-resistant Streptococcus pneumoniae and their conclusion was ....is mediated by a mosaic of genes encoding altered penicillin-binding proteins (PBPs). Nonetheless, S. pneumoniae has also developed non-PBP ...


2

This phenomenon is called Ototoxicity, which literally means "toxic for the ear". Mostly the cochlea or the auditory nerve are affected and almost all these cases are connected to medications as gentamicin or cisplatin. The reasons for this are that the cells are either driven into apoptosis or necrosis. This is caused by destroying mitochondria and ...


1

What attracts leukocytes and antibodies to pathogens in the first place? They just bump into them. If secreted antibody is already present in the blood then complement system can be activated. What attracts CD4+ cells to professional antigen-presenting cells (APC)? APC release chemokines. All that is known is that this is a CC-type chemokine ...


1

Ki is the equilibration dissociation constant. The smaller this constant is, the stronger (more specific) is the binding between the inhibitor and the enzyme. If the residual concentration is now higher than the Ki, for each molecule from the inhibitor which dissociates from the enzyme a new will bind (simply because of the concentration). If the ...


1

According to this site, for yeast (I assume this means Saccharomyces cerevisiae) you should use 50 µg/ml to 200 µg/ml; for fungi (!) use 100 µg/ml to 300 µg/ml. The site also stresses the importance of the pH of the medium. I think that, unless a Hansenula expert comes along, you will have to try an initial experiment to measure the sensitivity of ...


1

Doxycyline inhibits iNOS and TNF-alpha expression. It also influences secretion of IL-1beta, IL-8, and TNF-alpha, as well as other inflammatory cytokines. [These are results collected from multiple systems.] For appropriate references, see: Leite et al (2011). Anti-inflammatory properties of Doxycycline and Minocycline in experimental models: an in vivo ...


1

Antibiotics are a broader range of antimicrobial compounds which can act on fungi, bacteria, and other compounds. Although antibacterials come under antibiotics, antibacterials can kill only bacteria. Penicillin was the first discovered by Alexander Fleming antibiotic and antibacterial. There are certian classes of compounds which are bacteriostatic, which ...


1

Edited for Clarity: In order to invoke a memory response or create a memory response, there must be interaction with the Adaptive Immune System (usually CD40+ "Helper" T-Cells), and the interaction must come in the form of a protein since the MHC receptors only respond to proteins. Antibiotics are usually smaller macromolecules that directly cause slower ...


1

Of course there is a side effect, and this accounts for most "sick" feelings from taking it: your intestinal flora is destroyed by antibiotics, and this often leads to diarrhea.



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