Saturday, May 28, 2011

IB Biology, IB Chemistry on Antibiotics, Penicillin, Medicine, Drugs, Option D

IB Chemistry, Antibiotics, Penicillin, Medicine, Drugs, Option D


1928
Fleming discovered Penicillin from a fungi Penicillium notatum 
1940
Florey, Chain injected mice with bacteria, then with Penicillin
1945
Fleming, Florey, Chain awarded Nobel Prize (Medicine)

Keywords

  • Beta lactam Ring, inhibit enzyme in peptidoglycan cell wall synthesis
  • R side chain



Types of penicillin.

  • Natural, Penicillin G
  • Semi-synthetic, Penicillin V, Amoxicillin, Ampicillin
  • Antibiotic Resistant Bacteria produce enzyme penicillinase/beta-lactamases to destroy the ring.
  • Penicillinase resistant antibiotics, Methicillin, Oxacillin, Cloxacillin









Penicillin/ Cephalosporin, similar in function
  • Destroy cell wall
  • Beta lactam ring
  • Different side chains
  • From mould/fungi
  • Disrupt the synthesis of peptidoglycan
  • Ampicillin against Gram -ve
  • 1st to 4th generation drugs
  • 4th generation, strongest drug


Click HERE on types of antibiotics

Source taken from
http://jac.oxfordjournals.org/content/60/1/107/F1.large.jpg
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Video, History/ How Penicillin Works


Broad and Narrow Spectrum of Antibiotics
Keywords are
  • Narrow spectrum (specific), Penicillin and Sulfa drugs
  • Broad spectrum (wide range), Tetracyclines and Cephalosporin
  • Narrow is preferred
  • Bacteria develop resistance ( no inhibition zone )
Click HERE to get in 
Source from http://www.jyi.org/news/nb.php?id=555
................................................................................................................................................
Bacteria Fight back with MRSA
Keywords
  • Bacteria develop resistance/mutate
  • Hospital-acquired infections caused by Methicillin Resistant Staphylococcus Aureus (MRSA).
  • MRSA are resistant to Penicillin, oxacillin, amoxicillintetracycline,erythromycin.
Source and picture taken from
http://www.medicinenet.com/mrsa_infection/article.htm
http://www.knowabouthealth.com/extremely-resistant-superbug-triggers-global-concern/5338/
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MRSA to NDM1( SuperBug )



New Delhi metallo-ß-lactamase(NDM-1) a gene carried by bacteria, thus resistant to carbapenem ( powerful antibiotics )


Discovered in Dec 2009 in New Delhi, now detected in Pakistan, UK, States, Canada and Japan

Gut (E.coli) and lungs (Klebsiella), carry NDM1  gene



Carbapenems are beta-lactam antibiotics, developed to overcome antibiotic resistance.

SuperBug NDM1 is now resistant to carbapenems


Source from




Video on Emergence of NDM 1 Superbug
............................................................................................................................................
MRSA to NDM1 to CRKP
What is CRKP Superbug?
From CNN and Healthland
Emergence of Carbapenem Resistant Klebsiella Pneumoniae (CRKP),  found in West, LA. In seven months (2010), there were 356 cases of CRKP.
 CRKP are resistant to most antibiotics including carbapenem cause they produce carbapenemase enzyme.
Video on CRKP Superbug from ABC News

More video on CRKP
Click HERE to get to ABC News


Key notes on CRKP from CDC
  • Spread in health care + hospital, 40% die usually from pneumoniae
  • Prevention by washing hand
  • Hospital acquired infection, called Klebsiella ( gram-negative )
  • Klebsiella enter respiratory tract cause pneumoniae or blood to cause bloodstream infection.
......................................................................................................................................................
Bacteria are resistant and why we are losing the battle


World Health Day – 7 April 2011 was declared to combat drug resistance

Antimicrobial resistance: no action today, no cure tomorrow

Key notes from World Health Day,

  • World on brink of losing miracle cures.
  • Resistance is natural process and selective pressure is main cause
  • Evolution of bacterial genome under selective antibiotic pressure is the main cause for multi resistant strains.
  • Bacteria evolve/mutate and become resistant to the antibiotics. 
  • Drugs are dispensed too liberally
  • Overuse of antibiotics in animal feedstock and development of resistance strains
  • Over prescription of drugs by doctors
  • Use of 3rd generation, cephalosporins is linked to Gram -ve bacteria lactamase resistance
  • Bacteria develop resistance as quickly as we've been able to develop new antibiotics.
More Video for antibiotics. Click HERE to get in
Latest Outbreak killed 10 in Germany ( 29 May 2011 )
Shigatoxin/Vero toxin producing Escherichia coli (STEC/VTEC) causes haemolytic uraemic syndrome (HUS). E. coli are harmless found in gut/ faeces of animals
From MRSA to NDM1 to CRKP to STEC/VTEC
Sources from 
International Journal of Antimicrobial Agents 17 (2001) 357–363, World Health Day, Healthland
http://www.who.int/world-health-day/2011/en/

Thanks to all pictures and videos contributor for the above post

1 comment:

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