L6 Flashcards
Antimicrobial drugs include
- Antibiotics
Inhibit growth of bacteria in low dosage
From fungi, gram+ bac - Antiviral drugs
- Antifungal drugs
- Antiparasitic drug
Antibiotic action on bacteria
Bactericidal: kill bacteria
Bacteriostatic: interfere the growth of bacteria
Broad spectrum antibiotics
Against gram+- bacteria
E.g. tetracycline, ampicillin
Narrow spectrum antibiotics
usually gram+ only
penicillin G
Mechanism of action of antibiotics
- Inhibiting bacterial cell wall synthesis
- Inhibiting bacterial protein synthesis
- Inhibiting bacterial nuclei acid synthesis
- Inducing damage to bacterial plasma membrane
Example of 4 types of antibiotics
- Inhibiting bacteria cell wall synthesis
Penicillin - Inhibiting bacterial protein synthesis protein synthesis
Tetracycline - Inhibiting bacteria nuclei acid synthesis synthesis
Quinolones, fluoroquinolones - Inducing damage of bacteria plasma membrane
Daptomycin
Inhibiting bacteria cell wall synthesis 2 types
- Beta lactam antibiotics
Penicillin
AGAINST streptococci, staphylococcus
Narrow spectrum
Resistance to beta lactam axe
-) use penicillinase inhibitor: potassium clavulanate - Polypeptide antibiotic
Vancomycin
Very narrow spectrum of activity
High renal toxicity
Extreme important for comtrolling MRSA
Inhibit protein synthesis
Tetracycline
Broad spectrum
Inhibit nuclei acid synthesis
Quinolones & fluoroquinolones
Inhibit dna replication
Usually used to treat urinary infection
Induce damage to plasma membrane
Daptomycin
Inhibit fatty acid synthesis to attack plasma membrane
Induction of antimicrobial resistance
Drug can kill bacteria in the beginning
Small population of bacteria develop resistance by acquiring amr genes by gene mutation
Use of antibiotics represents a natural selection to challenge survival of bacteria
Susceptible bacteria dies but not resistant bacteria
Antibiotic resistant bacteria can reproduce, resistant gene can pass to other by gene transfer
R
Resistant bacteria eventually become the dominant population
Mechanism of resistance
- Inactivation of enzyme
Bacteria produce enzymes to inactivate the antibiotics
E.g. beta-lactamase digest beta-lactam ring - Blocking the entrance of antibiotics
Bacteria mutated to modified the structure of cell wall
Prevent the entry of aminoglycoside
3 alternation of the antibiotics target molecules
Alternated peptidoglycan structure so vancomycin cannot bind
- Rapid ejection of the antibiotics
Produce efflux pump to actively pump away antibiotics
factors accelerating spread of AMR
- Misuse of antibiotics
- Poor infection control & treatment in hospital
- Poor hygiene
- Lack of rapid laboratory test
- Lack of awareness and knowledge
- Travel
MRSA methicillin resistant staphylococcus aureus
Bloodstream infection
Infection at surgical site
E. Coli produced ESBL extended spectrum beta-lactamase
Cause UTI
Pneumonia
Wound infection
MDR / XDR TB
Multi-drug resistant tuberculosis
Antibiotic to isoniazid & rifampicin
Extensively drug resistant tuberculosis
Extended from MDR TB
Prevention of AMR
Role of intergovernmental
Optimise the use of antimicrobial medicine
Improve awareness and understanding of AMR
Strengthen knowledge through research
Role of health care giver
Prescribe antibiotic according to therapeutic guidelines
Educate patients to take antibiotics as prescribed
Educate patient about how to prevent infection and spread
Role of individual
Proper use of antibiotics
1. Do not request for antibiotics from doctor
2. Follow doctor’s prescription
3. Finish full course of antibiotic
4. Do no take leftover antibiotics
5. Do not share antibiotics with theirs
The one health concept
