Antimicrobial Agents - Inhibition Of DNA And Protein Synthesis

Antimicrobial Agents - Inhibition of DNA and Protein Synthesis

Bacterial chromosome replication

image

DNA replication

image

Bacterial Topoisomerases 

maintain DNA in appropriate state of supercoiling 

cut and reseal DNA

DNA gyrase (topoisomerase II) introduces negative supercoils 

Topoisomerase IV decatenates circular chromosomes 

these are the targets of the quinolone antibacterial agents 

Quinolones

bind to bacterial DNA gyrase and topoisomerase IV after DNA strand breakage 

prevent resealing of DNA 

disrupt DNA replication and repair 

bactericidal (kill bacteria)

Fluoroquinolone is particularly useful against

Gram +ves: Staphylococcus aureus, streptococci 

Gram -ves: Enterobacteriacea; Pseudomonas aeruginosa 

Anaerobes: e.g. Bacteroides fragilis 

many applications e.g. UTIs, prostatitis, gastroenteritis, STIs 

Adverse effects

Relatively well tolerated

GI upset in ~ 5% of patients 

allergic reactions (rash, photosensitivity) in 1 - 2% of patients 

image

Inhibition of Bacterial Protein Synthesis 

Macrolides 

in 1952: Erythromycin was isolated as the first macrolide (Streptomyces erythreus) 

Newer macrolides: clarithromycin, azithromycin 

Structurally they consist of a lactone ring (14- to 16-membered) + two attached deoxy sugars 

Mode of action 

bind reversibly to bacterial 50S ribosomal subunit 

causes growing peptide chain to dissociate from ribosome → inhibiting protein synthesis 

bacteriostatic (stops reproduction)

image

Macrolides’ spectrum of activity

good antistaphylococcal and antistreptococcal activity 

treatment of respiratory & soft tissue infections and sensitive intracellular pathogens • e.g. Chlamydia, Legionella 

Adverse effects

Generally well tolerated

nausea 

vomiting 

diarrhoea 

rash 

Aminoglycosides

large family of antibiotics produced by various species of Streptomyces (“mycin”) and Micromonospora (“micin”) 

include: streptomycin, neomycin, kanamycin, gentamicins, tobramycin 

Structure = linked ring system composed of aminosugars and an aminosubstituted cyclic polyalcohol 

Mode of action of aminoglycosides

Bind irreversibly to 30S ribosomal subunit 

disrupt elongation of nascent peptide chain 

translational inaccuracy → defective proteins 

bactericidal 

image

Spectrum of activity 

broad spectrum; mainly aerobic G-ve bacilli (e.g. P. aeruginosa) 

used to treat serious nosocomial infections (hospital acquired infections)

First TB antibiotic

Used for cystic fibrosis 

Adverse effects

all aminoglycosides have low Therapeutic Index (only a small amount needed to become toxic)

renal damage, ototoxicity, loss of balance, nausea 

More Posts from T-b-a-blr-blog and Others

6 years ago
• Microbiology Cheat Sheets For The Comprehensive Final. We Were Allowed Two Pages, Front And Back.
• Microbiology Cheat Sheets For The Comprehensive Final. We Were Allowed Two Pages, Front And Back.
• Microbiology Cheat Sheets For The Comprehensive Final. We Were Allowed Two Pages, Front And Back.
• Microbiology Cheat Sheets For The Comprehensive Final. We Were Allowed Two Pages, Front And Back.

• Microbiology cheat sheets for the comprehensive final. We were allowed two pages, front and back. I ended up getting a 95%! •

6 years ago

Mycobaterium tuberculosis PATHOGENESIS

Facultative intracellular

Mycobaterium Tuberculosis PATHOGENESIS

Sulfatides: inhibit PHAGOLYSOSOME FORMATION allowing intracellular survival.

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

Mycobaterium Tuberculosis PATHOGENESIS

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

6 years ago
Me This Week

Me this week

6 years ago

40 Study Tips & Tricks

I thought to write down the “script” to one of my most viewed videos, with 40 study tips & tricks. It’s easier to read them and pass on the word!

Organization Tips:

1. Incorporate homework and classes in you daily planner – that will give you an overall glimpse of how your week will be about and how much time you need to spend in your studying sessions!

2. Color coordinate classes – be it notes, your planner, your textbooks or binders, pick a unique color for each class and work around the hues of that color to get more organized!

3. Make your own syllabus – if your professor doesn’t provide a syllabus for your class, try to make one before the school year working around your given textbooks or other given material.

4. Make study guides – make a study guide from your syllabus and draw before each topic two boxes: one for a midtest and one for the final test. When you have one of these tests, check the boxes when you’ve finished studying the chapter so you won’t miss anything!

5. Reference your material throughout – most of the times, we students work with in-class notes, textbooks and a syllabus. Since we get small bits of information here and there it’s important to reference every page throughout all your material so you can quickly access your information without having to flip endlessly through pages!

6. Keep a dashboard nearby – Whenever you use a notebook or a binder, make a dashboard on the first page with post it notes so you can quickly scribble any questions, homework or page numbers. When you get home, you just need to open your dashboard and attend those notes.

7. Print any tests, exercises and exams you can find – keep those in the end of your binder. These are perfect to practice before exams and tests because they really reflect what you will be tested about. Set an alarm clock for the deadline and start working on those!

8. Condense – organization disappears when you have too many of everything. Working with more than one planner in your life will make everything chaotic. If you think you need a second planner because you don’t have enough space to write in the first one, it’s because you don’t have available time as well. Don’t fool yourself and set achievable goals!

9. Customize your textbooks – most of the times, textbooks are formal books where information is hard to come by. Make your own tabs and write every chapter on them so they stick out – flag any charts, tables or graphics. Everything needs to be incredibly accessible!

10 Print a special planning sheet before finals: Organizing your studying by chapters and/or topics before finals is tremendously important since it lets you organize the amount of time you dedicate to each subject,

Study Sessions and Time Management

11. Save at least one afternoon or one morning a week for intensive studying. These is your “life-saver” – when you get so full of homework and projects that you can’t incorporate them into your daily academic routine, one free afternoon to organize your school life will really come in handy! Make an appointment with yourself!

12. Prepare in advance – although most professors may not ask you to prepare a class in advance, if you have the means to, go ahead. Grab a sheet and make a summary of the chapter your class will be about. Write the major topics and key information and take that guide to class. When your professor repeats previously studied information, you will be able to understand everything much better!

13. Never leave something behind – Even if you have a more light class, where professors don’t request homework or any side projects, don’t let that fool you! Be disciplined and be your own professors! Make your own projects and learn everything you can so you can nail those finals when they arrive.

14. Write your questions – most of the time, in a heavy study session, we come up with tons of questions and sometimes we just leave them behind. Write them down in your dashboard or a small notebook and ask your professors (personally or via e-mail). You can also ask your schoolmates in a facebook group created for that purpose!

15. Set an alarm clock and reward yourself – even if you study during an entire afternoon your studying will be pointless if you don’t take regular breaks. Set an alarm clock for one hour/one hour and a half and then take a 15 minute break. Never study for more than 2 hours straight! Even if you don’t notice, you’ll get less and less focused.

16. . Make a list – before each study session I like to grab my notepad and write down everything that I need to do before my session ends: the chapters I need to read, the pages I need to go through and the homework I need to complete. Sometimes I even write theses lists when I’m in college so I’ll have more determination to complete those tasks once I get home.

17 Work on the least interesting thing first. There are always classes or projects that we like the least – and those are the ones that we need to tackle first. You will start your studying session concentrated, which will let you go through the worst tasks faster.

18 Print, print, print. try to print everything you can and never study from your computer. Having your PDF files printed at hand will let you concentrate better, highlight and write some notes in the margins. You can take these everywhere with you and even turn them into small guides for future classes!

19. If you finish ahead, don’t quit. Perhaps the time you’ve saved for your study session has come to an end way before you have planned. That doesn’t mean you should stop right now – Take that time to review what you’ve learned so far or prepare other classes ahead of time!

20. Study in an organized space – make your own studying corner – bring everything you will need, from textbooks, binders and notebooks, to a cup of coffee and your computer. Keep them neatily organized on your desk so everything is at hand and on sight. Put on some soft background music (links down below) and adjust the lightning.

In class notes

21. If your professor provides PowerPoint slides before each class, print them (six or four per page) and bring them to class. Write in the margins and more throughout information in the back so it’s all condensed and tight. This is where you’ll take your notes. If you prefer to write on lined paper, think about copying some ruled paper to the back of your printed slides.

22. If your professor asks you to prepare your class in advance, try to make a small guide for each class. Open the comments column in MSWord and print the pages with that column. When you go to class, incorporate the in-class notes in that column, next to the relevant information so everything is nice and condensed.

23 If you are in a information-heavy class, try to adopt the Cornell method, which is the best, in my opinion, when you need to be a fast writer. There’s a video right here on how to use this method.

24. If you are in a bits-and-pieces class, which is that kind of class where the professor just gives a few key points and then gives practical examples or makes you work in group, try to adopt the box method – you can draw these boxes yourself or make them with post it notes – these are way more visual and perfect to memorize information.

25. Write in-class flashcards – if you don’t have flashcards around, make tiny flashcards on the top of your notes, where you cover the definitions you’ve written with the name of the definition. Each time you open your notes, try to remember the hidden definition. Automatic studying, every time!

26. Participate in class – nothing better than to be actively involved in your class discussion. For most of us, shy creatures, participating can be dreadful – but once you get out of your box, you’ll see how participating really makes you understand the subject!

27. If you have any questions during class, raise your hand and ask them. If your professor doesn’t like being interrupted, write them down and approach them in the end of the class. Sometimes, the little things we don’t understand are exactly the ones that come up on the final exam!

28. Ask for examples. Examples are probably the thing that makes your brain connect the information faster. If your professor isn’t keen on providing examples, suggest your own and see if your answer comes up right. Sometimes, examples are the thing that really makes us understand our material and our definitions, since they transform formal information into relatable events.

29. Sit at the front. It sounds too straightforward but sitting at the front really makes wonders. You won’t get distracted by what you classmates are doing, you will focus on the professor, who is right in front of you and you will resist the temptation of going to Facebook and Instagram during a boring presentation.

30. Write a brief summary at the end of the class. During those five minutes where everyone is dismissed and leaving the room, write a brief summary of that classes’ key points in the back of a page – this is fundamental in the Cornell method but can be used in any other method as well.

Finals Guide

31 Skim through your material two times: at first, you should start by studying your material starting from the end. The last lessons will be fresh in your memory and it’s very important to reinforce your knowledge on these while you can. In the second reading, you should start from the beginning, as usual. It’s important to make these two readings so you can go through the information in a much more flexible way.

 32. Make a mindmap of each chapter. A mindmap is a chart that relates key words and important information, making it easy to understand the relationship and hierarchy between such key words. Use colors and images to memorize your material better. Oh, and don’t forget to check out my video on how to make mindmaps!

33. Read each of the titles and try to say out loud its contents, explaining each concept and the relationship between them. Imagine you are the teacher and are lecturing that subject to a crowd. If you skip any of the subjects, do it all over again. The more you repeat, the better you will memorize.

34. It’s time for some flash cards!  Write the topic or the title on one side and the meaning or the explanation on the other. Try to cover as many topics or titles as you can and go through your cards while memorizing as best as you can each of the concepts. Try to do it backwards if you have time to do so!

35. On the day before the exam, skim through your mindmaps and flash cards again and always try to study while talking. Saying your content out loud will force your brain to relate information in a much more cohesive way and you’ll memorize everything much better.

36. Read the entire exam from top to bottom. Underline or circle any important words that you think will be crucial in you answer. After that, calculate how much time you should spend answering each question: this simple calculation will take only twenty seconds and will help you organize your time. Try to save five minutes at the end for revisions.

37. If you are solving a written exam and not multiple choice, try as much as possible to organize each answer in a structured way, saving two lines just to present your line of thought and writing each different argument in a different paragraph. Draft a conclusion at the end to underline the centre of your answer. Sometimes softly underlining some keywords is important to make your professor notice that you’ve correctly given importance to certain concepts.

38. Use these symbols for each question: one dot if you aren’t sure of the answer, two dots if you are sure of your answer and a circle if you are completely unaware of your answer. Start by answering any question with two dots; after those are all answered, go on through the two dots question. Leave the circle questions to the end – and ALWAYS answer them! Even if you don’t know what they’re about, who knows if you will be able to come up with something right?

39. Review your test one final time – many times, we make a lot of mistakes under stress and now is when you should spot them and amend them. This can be the difference between a B and an A!

40. Don’t take this too seriously – school is an important aspect of our lives but it isn’t everything. Failure comes many times and these failures can even drive you away from something that was simply not meant to be. Don’t stress out because everyone goes through the same!

6 years ago
New Background! Download Higher Quality Photo Here!

New background! Download higher quality photo here!

https://drive.google.com/file/d/1F5SlJmB8YiNNtGuKrc-QtMnrrjZ1tOHL/view?usp=sharing

6 years ago
Staphylococcus Epidermidis Is A Coagulase Negative, Gram-positive Coccus. The Organism Uses Sophisticated

Staphylococcus epidermidis is a coagulase negative, Gram-positive coccus. The organism uses sophisticated regulatory networks to adapt its metabolism to suit varying environmental conditions. S. epidermidis relies on biofilm formation to protect cells from the host immune system and other anti-microbial molecules.

6 years ago
Colon: Pseudomembranous Colitis Due To Clostridium Difficile (pseudomembranous Inflammation) Note The

Colon: pseudomembranous colitis due to Clostridium difficile (pseudomembranous inflammation) Note the gray-yellow pseudomembrane covering the entire mucosal surface. Damage is due to a toxin produced by C. difficile. Similar to diphtheria, the toxin produces necrosis of the mucosa and submucosa without actual invasion by the bacteria. A toxin assay of stool is the best method for diagnosing the disease. Ampicillin is the MC drug causing pseudomembranous colitis and does so by destroying colonic bacteria that normally keep C. difficile in check.

6 years ago

What is Acute or Subacute Bacterial Endocarditis?

Acute or Subacute Bacterial Endocarditis is an infection of the heart’s endocardium. The endocardium is the inner lining of the heart muscle, which also covers the heart valves. Bacterial Endocarditis can damage or even destroy your heart valves. The difference between acute and subacute bacterial endocarditis is acute bacterial endocarditis is a sudden onset, whereas subacute bacterial endocarditis is a gradual onset.

Acute endocarditis most often occurs when an aggressive species of skin bacteria, especially a staphylococcus (staph), enters the bloodstream and attacks a normal, undamaged heart valve. Once staph bacteria begin to multiply inside the heart, they may send small clumps of bacteria called septic emboli into the bloodstream to spread the infection to other organs, especially to the kidneys, lungs and brain. Intravenous (IV) drug users are at very high risk of acute endocarditis, because numerous needle punctures give aggressive staph bacteria many opportunities to enter the blood.If untreated, this form of endocarditis can be fatal in less than six weeks.

Subacute endocarditis is caused by one of the viridans group of streptococci (Streptococcus sanguis, mutans, mitis or milleri) that normally live in the mouth and throat. Streptococcus bovis or Streptococcus equinus also can cause subacute endocarditis, typically in patients who have some form of gastrointestinal cancer, usually colon cancer. Subacute endocarditis tends to involve heart valves that already are damaged in some way, and it usually is less likely to cause septic emboli than acute endocarditis. If untreated, subacute bacterial endocarditis can worsen for as long as one year before it is fatal.

6 years ago
Hey Guys, Since My Previous Post On Morning Routines Was Very Well Received,  I Decided To Make A Night
Hey Guys, Since My Previous Post On Morning Routines Was Very Well Received,  I Decided To Make A Night
Hey Guys, Since My Previous Post On Morning Routines Was Very Well Received,  I Decided To Make A Night
Hey Guys, Since My Previous Post On Morning Routines Was Very Well Received,  I Decided To Make A Night

Hey guys, since my previous post on Morning Routines was very well received,  I decided to make a night version. This small infographic thingy outlines the things I do at night to prep myself for rest, as well as some other things you could try to ensure you get a good night’s sleep. Hope this helps, and don’t hesitate to drop me an ask if you have any questions!

P.S. the typefaces used are Bromello and Montserrat

  • ashish4989
    ashish4989 reblogged this · 1 year ago
  • puellamaligna
    puellamaligna liked this · 2 years ago
  • nysa22194
    nysa22194 liked this · 2 years ago
  • mxchaelangelo
    mxchaelangelo liked this · 2 years ago
  • arcadia-the-dragon
    arcadia-the-dragon liked this · 4 years ago
  • rosfarm
    rosfarm liked this · 4 years ago
  • a-little-bit-of-lots-of-stuff
    a-little-bit-of-lots-of-stuff liked this · 4 years ago
  • livingintherainofhell
    livingintherainofhell liked this · 4 years ago
  • rani-xi
    rani-xi liked this · 4 years ago
  • forensicfiless
    forensicfiless reblogged this · 4 years ago
  • moveddeleted
    moveddeleted liked this · 4 years ago
  • riversphoenixx
    riversphoenixx reblogged this · 4 years ago
  • mgadagat
    mgadagat liked this · 4 years ago
  • tsuruying
    tsuruying liked this · 4 years ago
  • kelsyer77
    kelsyer77 liked this · 4 years ago
  • adrenaline-promote
    adrenaline-promote liked this · 4 years ago
  • aristotlante
    aristotlante liked this · 4 years ago
  • keeplittlefragments
    keeplittlefragments liked this · 4 years ago
  • audivampion
    audivampion liked this · 4 years ago
  • lambentlightrays
    lambentlightrays liked this · 4 years ago
  • snevar6
    snevar6 liked this · 4 years ago
  • maliamora
    maliamora reblogged this · 4 years ago
  • maliamora
    maliamora liked this · 4 years ago
  • rasmaadelia12
    rasmaadelia12 liked this · 4 years ago
  • lara3005
    lara3005 liked this · 5 years ago
  • medintp
    medintp reblogged this · 5 years ago
  • whoamikiding15
    whoamikiding15 liked this · 5 years ago
  • lougf
    lougf liked this · 5 years ago
  • satisfyingsins
    satisfyingsins liked this · 5 years ago
  • jood111214
    jood111214 liked this · 5 years ago
  • thefanqingan
    thefanqingan reblogged this · 5 years ago
  • thefanqingan
    thefanqingan liked this · 5 years ago
  • sanctusabyssi
    sanctusabyssi liked this · 5 years ago
  • ezetimib
    ezetimib reblogged this · 5 years ago
  • ezetimib
    ezetimib liked this · 5 years ago
  • microbiomedvet-blog
    microbiomedvet-blog reblogged this · 5 years ago
  • ghfzdgj
    ghfzdgj liked this · 5 years ago
  • hello-i-am-insane
    hello-i-am-insane liked this · 5 years ago
  • japollo-7
    japollo-7 reblogged this · 5 years ago
  • japollo-7
    japollo-7 liked this · 5 years ago
  • damagedthingss
    damagedthingss liked this · 5 years ago
  • hako-no-eu-no-neko
    hako-no-eu-no-neko reblogged this · 5 years ago
  • hako-no-eu-no-neko
    hako-no-eu-no-neko liked this · 5 years ago
  • sugaspicelatte
    sugaspicelatte liked this · 5 years ago
  • sweet-wake-up
    sweet-wake-up liked this · 5 years ago
  • sircharleschewbacca
    sircharleschewbacca liked this · 5 years ago
t-b-a-blr-blog - Untitled
Untitled

195 posts

Explore Tumblr Blog
Search Through Tumblr Tags