Antimicrobials and Microbes Flashcards
What are the most common organisms causing infection in the following systems and what antibiotics are used to treat them:
- Skin/Soft tissue
- MSK
- Respiratory
- Skin: Staph Aureus, Coagulase negative Staph (S.Epidermidis), Group A Strep (S.Pyogenes), MRSA
- MSK: same as above, Pseudomonas for diabetic foot, TB)
- Respiratory: S.Pneumoniae, H. Influenzae, Legionella, Mycoplasma, Rhinovirus, Adenovirus, Influenza
What are the most common organisms causing infection in the gastrointestinal system and what antibiotics are used to treat them?
Diarrhoea: Rotavirus, Adenovirus, Campylobacter, C.Diff, Salmonella
Peritonitis: Enterobacteriacae
What are the most common organisms causing infection in the following systems and what antibiotics are used to treat them:
- Genitourinary Tract
- CNS
- Endocarditis
GU: Enterobacteriacae, P.Aeruginosa, N.Gonnorrhea, C.Trachomatis
CNS: S.Pneumonia, N.Meningitidis, HSV, TB, Listeria (>55 or immunocompromised)
Endocarditis: Strep Viridans, Enterococci, S.Aureus, MRSA
What are the most common organisms causing infection in the following systems and what antibiotics are used to treat them:
- Line infections
- Hospital acquired
- Sepsis
What is the gram stain of the following:
- S.Aureus
- S.Epidermidis
- C.Diff
- S.Pneumoniae
- S.Pyigenes
- H.Pylori
- Salmonella
- Campylobacter
- Pseudomonas Aeruginosa
- H.Influenzae
What are some examples of common parasites?
- Protozoa: malaria, entamoeba histolytica, giardia lamblia
- Hyatid disease
- Schistosomiasis
What are some examples of notifiable diseases?
- Mumps
- Measles
- Food poisoning
- Malria
- SARS
- TB
- Tetanus
- Whooping cough
What are some bacteria that are encapsulated?
- N.Meningitidis
- H.Influenzae
- S.Pneumoniae
These are destroyed in spleen so sickle cell or after splenectomy need prophylactic vaccinations as higher risk of infection from these
What is the definition of the following:
- Endotoxin
- Exotoxin
- Enterotoxin
Endotoxin: LPS complex on outer membrane of gram negative bacteria that can activate complement and trigger inflammatory response
Exotoxin: toxin secreted by bacteria that works at different site to bacterial growth
Enterotoxin: exotoxin that targets the gut e.g C.Diff
How can antibiotics be grouped by their actions?
Affect:
- Cell wall synthesis
- Nucleic Acid synthesis
- Protein synthesis
What are the two different categories of antibiotic resistance and give some examples of each?
Intrinsic: due to structural characteristics e.g vancomycin cannot outer membrane of gram negative bacteria
Acquired: bacteria have evolved via mutation due to selection pressue from antibiotic use (including agricultural antibiotics)
What are some examples of antibiotics that inhibit cell wall synthesis?
Beta lactams: penicillins, carbapenems, cephalosporins
Non beta lactams: glycopeptides
What is Tazocin?
Piperacillin + Tazobactam
(beta lactam + betalactamase inhibitor)
What are the indications for the following antibiotics:
- Benzylpenicillin (Penicillin G)
- Phenoxymethylpenicillin (Penicillin V)
- Co-Amoxiclav
- Tazocin
- Flucloxacillin
- Vancomycin
- Cetriaxone
Penicillin G: usually gram positive such as streptococci (chest, endocarditis, cellulitis), meningococcus
Penicillin V: prophylaxis after splenectomy, rheumatic heart disease
Co-Amoxiclav: chest, pyelonephritis, cellulitis, bone
Tazocin: broad spectrum gram positive and negative, neutropenic sepsis, nosocomial infection
Flucloxacillin: staphylococcus e.g skin, bone, post viral pneumonia
Vancomycin: complicated gram positive e.g MRSA, oral for C.Diff
Ceftriaxone: meningococcus
What are some examples of antibiotics that inhibit protein synthesis?
- Aminoglycosides
- Macrolides
- Tetracyclines
- Fusidic acid
- Chloramphenicol
What are the indications for the following antibiotics and what are some side effects:
- Gentamicin/Tobramycin
- Azithromycin/Clarithromycin/Erythromycin
- Tetracycline/Doxycycline
What are some examples of antibiotics that inhibit nucleic acid synthesis?
- Folate synthesis inhibitors: trimethoprim
- Fluoroquinolones: ciprofloxacin, levofloxacin
- Metronidazole
- Rifampicin
What are the indications for the following antibiotics and what are the side effects:
- Trimethoprim
- Ciprofloxacin
- Metronidazole
- Rifampacin
Which antibiotics have a risk of the following:
- Long QT
- C.Diff
- Nephrotoxic
- Ototoxic
Long QT: macrolides, fluoroquinolones, azole antifungals
C.Diff: cephalosporins, fluoroquinolones, clindamycin, amoxicillin, ampicillin
Nephrotoxic: aminoglycosides, glycopeptides (vancomycin, gentamicin)
Ototoxic: gentamicin/tobramycin (aminoglycosides)
How are staphylococcal organisms classified and what are some infections that they cause?
Gram positive and coagulase +ve/-ve
S.Epidermidis (coag -ve): less virulent and usually only infection if immunosuppressed or foreign material e.g prosthetic joint, heart valve, catheter, IV line
S.Aureus (coag +ve): toxic shock, cellulitis, impetigo, endocarditis, mastitis, septic arthritis
How are staphylococcal infections treated?
- Usually penicillins
- If MRSA use vancomycin
How are streptococcal organisms classified and what are some infections they cause?
Gram Positive, Haemolytic a/b/y, Lancefield Group
S.Pyogenes (B Haemolytic Group A): tonsillitis, scarlet fever, pneumonia, necrotising fascitis
S.Pneumoniae: otitis media, meningitis, pneumonia
S.Viridans: endocarditis from dental origin
What are some examples of gram positive bacilli?
- C.Diff
- C.Botulinum
- Listeria
What are some examples of gram negative cocci and bacilli ?
Cocci
- N.Meningitidis
- Moraxhella Catarrhalis
Bacilli
- P.Aeruginosa
- E.Coli
- Klebsiella Pneumoniae
- Haemophillus influenzae
- Whooping cough/Bordetella Pertussis
