How To Remember Lysteria Monocytogenes Tumbling Motility?

Antimicrobial Agents  - Cell wall inhibitors

Based on mode of action • divided into families based on chemical structure

 Modes of action Interference with: 

cell wall synthesis 

protein synthesis 

nucleic acid synthesis 

plasma membrane integrity 

metabolic pathway 

Inhibitors of Bacterial Cell Wall (peptidoglycan) Synthesis 

The Beta-lactam Family 

The Glycopeptides 

Peptidoglycan is composed of N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) repeat units, and amino acids.  Each NAM is linked to peptide chain and the peptide chains are cross-linked.

β-lactams 

Includes penicillin derivatives (penams), cephalosporins (cephems), monobactams, and carbapenems.

class of broad-spectrum antibiotics containing a β-lactam ring

Bacterial transpeptidase enzymes are responsible for catalysing cross-linking of the peptide chains

β-lactam ring bind to these transpeptidases – this inhibits cross-linking between peptide chains and prevents synthesis of stable PG

Cell wall synthesis ceases and the bacterial cells eventually die due to osmotic instability or autolysis. 

Glycopeptides 

Polypeptide agents - basic structural elements amino acids 

Vancomycin: 

complexes with peptide portion of peptidoglycan’s precursor units 

vancomycin is a large hydrophilic molecule able to form hydrogen bonds with the terminal D-alanyl-D-alanine moieties of the NAM/NAG-peptides

preventing PG transglycosylation reaction – PG precursor subunits (NAG-NAM+peptide) cannot be inserted into peptidoglycan matrix;

Vancomycin also alters bacterial-cell-membrane permeability and RNA synthesis

Uses:  serious Gram positive infections e.g. MRSA wound infection

Adverse effects:

damage to auditory nerve 

hearing loss (ototoxicity) 

“Red man/neck” syndrome - rash on face, neck, upper torso 

Mycobaterium tuberculosis PATHOGENESIS

Facultative intracellular

Sulfatides: inhibit PHAGOLYSOSOME FORMATION allowing intracellular survival.

Cord Factor (serpentine growth in vitro): disrupts mithochondrial respiration and oxidative phosphorilation and inhibits leukocyte migration.

Tuberculin + Mycolic Acid: type IV hypersensitivity (delayed hs), Cellular Mediated Immunity (CMI)

Hi optom! I'm very new to the studyblr community and it's my first term of university. I was a straight A student in high school and i am not performing well in my classes. In fact... I'm doing terribly. About a B to B- average. I know I'm probably not the first to go through so I've been trying to find posts that help students cope with this. Resources. Helpful tips. Is there a tag you can recommend? Any posts that you've encountered/wrote that I could peruse? Thank you very much for any help!

Hey there, thanks for asking. This is actually a very common problem experienced by people as they progress from high school to university. 

The problem is that mediocre study techniques and a combination of natural ability may have gotten you straight As whilst in high school, but it’s just not going to cut it in university. Cracking down on yourself and sitting down for more hours isn’t going to make your grades much better; it’s just doing more of the same mediocre studying. 

So you basically need to read up on good studying techniques and actually apply them to your studies. 

Everything You Need to Cover To Succeed As A Student

I actually have a web directory of all my study tips which already lists all these links.

So because the problem you have at its base is most likely that you’re using high school level techniques to tackle university-level problems, you’ll need to find resources on all areas related to good studying. For some of these areas, I have a related post, but for the more generalised topics like procrastination, I haven’t yet put one out because if I do, I want to be certain that the post will be unique, useful and practical. 

Without further ado, here’s a list of all the tags/areas you should work through and evaluate whether you need to change your current study habits if you want to be a 4.0/HD student at university. 

Firstly, have a read of my recent answer about 20 Things You Can Do To Prepare for University, and click through to any of the parts of my 15-Part University 101 Series. 

Time management

Organisation (see Part 3 Studying and Part 8 Four Secrets from University and Part 11 Adapting to Uni Studying which covers how you can manage university workloads on the whole and specific changes to your studies you should make)

Motivation

Discipline / Staying Focused

Procrastination (see post by @samsstudygram​)

Study Methods (I’ve got one on the Blank Paper Method and the Cornell Method)

Exams (I’ve got a multi-part series in the works)

Study Materials (see Part 2 of my University Series for some tips)

Studying from Textbooks (see Part 12 How To Study From Textbooks in Uni which deals with this specifically)

Self Care (you can see my tag here of my own + useful curated posts)

Spaced Repetition (use Anki!)

Study Space (I have a masterpost with tips here)

Hope that helps! If you have a specific question about any areas then let me know! 

nasty moodboard

Mechanism of Fever

Difference between Blood Agar and Chocolate Agar

Hi everyone!

I’ll tell you in short about Nutrient agar first

It is a simple basal medium used for growth of common pathogens

It constitutes peptone water, meat extract and agar

Difference between Blood Agar and Chocolate Agar

What is common between Blood agar and Chocolate agar?

Both are enriched media

Used for the growth of Gram positive cocci and fastidious organisms like Neisseria & Haemophilus species

Can be used to indicate hemolysis

What are fastidious organisms?

They require specialized environments due to complex nutritional requirement

What is the difference between Blood agar and Chocolate agar?

The difference lies in how the media are made

How is Blood agar made?

Nutrient agar is sterilized by autoclave, cooled to 50°C and sterile sheep blood (5-10%) is added gradually and poured into plates

How is Chocolate agar made?

Nutrient agar is sterilized by autoclave, cooled to 75-80°C and sterile sheep blood (5-10%) is added gradually and poured into plates

How is the difference in temperature significant?

Certain organisms such as Haemophilus species require V factor for growth (complex nutritional requirement)

Factor V is present in blood but it is present inside the red blood cells (RBC)

These organisms can not utilize V factor which is trapped inside the RBC’s in Blood agar

When Blood agar is heated to 80-90°C for a few minutes (boiled blood agar), the V factor is released from within the erythrocytes and made available to the organism for utilization

Some strains of Neisseriae and Diphtheroids require V factor too

That’s why these media are superior to plain Blood agar for growing organisms requiring V factor

What is V fatcor?

V fatcor is a coenzyme, Nicotinamide Adenine Dinucleotide (NAD) or Nicotinamide Adenine Dinucleotide Phosphate (NADP) which acts as a hydrogen acceptor in the metabolism of cell

So to conclude, Chocolate agar is a type of blood agar in which the blood cells have been lysed by heating for growing fastidious organisms :)

Did you know?

Modified Thayer Martin is a type of chocolate agar which contains antibiotics (Vancomycin, Nystatin & Colistin) to suppress growth of other bacteria and promote growth of  N gonorrhoeae

*phew* That’s all for today!

The image is my first photoshop work on the site, hope you like it =D

Just to remind you guys, Chocolate agar contains no chocolate, they simply named it after the yummy color :P

-IkaN

I made a lymph drainage sticker for the immuno section of first aid

You can get the Sticker here: https://www.redbubble.com/people/histrionicole/works/29980305-lymph-node-drainage?asc=u&p=sticker

Amazing web site!

fungal infectors by systems 

Sorry guys haven’t been updating much lately 

Microbial Genetics