Actinomyces Israelii

Pneumonia & Meningitis Timelines

study tip request: studying on public transport (or sth related like how to know what to record when you record yourself saying notes so that you can listen to them on public transport)

Best Way to Make Study Recordings for Yourself

Testing yourself is the most effective way to learn a topic, so this one is fairly straightforward. For recording:

Formulate an examination style question, and run through the answer in your head, organising your thoughts. 

Then record the question, and mouth silently the answer fluently (reason being that just thinking in your head may result in too little or too much silence. 

Leave a few extra seconds of silence for thinking time (~3-5 seconds). 

Answer the question aloud in the recording (I’d suggest a brief one)

Rinse and repeat until you have enough to last you the whole commute. 

Hope that helps! For more tips on how to spend time on commutes, check out my post on Staying Productive No Matter How Much Time You Have :)

volutin granules are an intracytoplasmic storage form of complexed inorganic polyphosphate, the production of which is used as one of the identifying criteria when attempting to isolate Corynebacterium diphtheriae on Löffler’s medium….look like chines letters…as given below

11.19.17

2 more days until break

Music mood: Mili - Miracle Milk

Microbiology Genetics

Transformation

Conjugation:  F+ –> F-  &  Hfr –> F-

Transposition 

Transduction: Generalized   &  Specialized

Gram staining

fungal infectors by systems 

Sorry guys haven’t been updating much lately 

Stuff in my Office

From 1930. This well-dressed young scientist is experimenting with The Air. Exactly what he is doing is a mystery.

July 25 …. I finally get it!  He’s holding an eye dropper with a bulb on the end. I thought it was a pair of chopsticks! He’s picking up pieces of paper using the vacuum from squeezing the bulb! Still very formal, though …

Antimicrobial Agents - Inhibition of DNA and Protein Synthesis

Bacterial chromosome replication

DNA replication

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 

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)

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 

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 

11.19.17

2 more days until break

Music mood: Mili - Miracle Milk