Infectious disease Flashcards
What are the categories bacteria can fall in to
Aerobic and anaerobic
Gram positive and negative
Define aerobic and anaerobic bacteria
Aerobic bacteria require oxygen to respire. Anaerobic do not.
Define gram positive and gram negative bacteria
Gram positive bacteria have a thick peptidoglycan cell wall that stains with crystal violet stain.
Gram negative bacteria do not have this thick wall and don’t satin violet.
Examples of gram positive cocci
Staphylococcus
Streptococcus
Enterococcus
Examples of gram positive rods
Corney Mike’s list of basic cars
Corneybacteria
Mycobateria
Listeria
Bacillus
Nocardia
Examples of Gram positive anaerobes
CLAP
Clostridium
Lactobacillus
Actinomyces
Propionibacterium
Examples of gram negative bacteria
Most of them
Neisseria meningitis
Neidderia gonorrhoea
Haemophilia influenza
E. coli
Klebsiella
Pseudomonas aeruginosa
Moraxella catarrhalis
Define atypical bacterria
Bacteria that cannot be cultures or detected using gram staining.
Examples of atypical bacteria
Legions of psittaci MCQs
Legionella pneuophila
Chlamydia psittaci
Mycoplasma pneumoniae
Chlamydydophila pneumoniae
Q fever (coxiella burneti)
Define MRSA
Methicillin resistant staphylococcus aureus
Bacteria that have become resistant to beta-lactam antibiotics such as penicillin’s, cephalosporins and carbapenems.
Antibiotic treatment options for MRSA
Doxy
Clindamycin
Vancomycin
Teicoplanin
Linezolid
Define ESBLs
Extended spectrum beta lactamase bacteria
Bacteria that have developed resistance to beta-lactam antibiotics as they produce beta-lactamase enzymes that destroy it.
Abx options for ESBLs
Carbapenems - meropenem or imipenem
What are the main types of antibiotic
Bacteriostatic
Bacteriocidal
Define bacteriostatic
Abx that stop the reproduction and growth of bacteria
Define bacteriocidal
Abx that kill the bacteria directly.
Examples of antibiotics that inhibit cell wall synthesis
Beta-lactams - Penicillin, carbapenems (meropenem), cephaosporins ()
Not beta-lactams - Vancomycin, teicoplanin
Examples of antibiotics that inhibit folic acid metabolism
Trimethoprim
Sulfamethoxaole
Co-trimoxazole
What is the action of metronidazole
Nucleic acid synthesis inhibition - effective against anaerobes
Examples of antibiotics that inhibit protein synthesis by targeting ribosomes
Macrolides - erythromycin, clarithromycin, azithromycin
Clindamycin
Tetracyclines - Doxycycline
Gentamicin
Chloramphenicol
What other classes of abx can penicillin allergic patients not have
Cephalosporins
Carbapenems
Common causes of pneimonia
Streptococcus pneumonia - 50%
Haemophilus influenzae - 20%
Antibiotics of choice in pneumonia
Amoxicillin
Erythromycin/clarithromycin
Doxycycline
Atypicals - macrolides (clarithromycin), quinolones (levofloxacin), tetracyclines (doxy)
Most common causes of UTI
E. coli!
Antibiotics of choice in UTI
Trimethoprim
Nitrofurantoin
Pivmecilinam
Amoxicillin
Cefalexin
Define cellulitis
Infection of the skin and soft tissue underneath.
Presentation of cellulitis
Erythema
Red
Hot
Swollen
Tense
Oedematous
Bullae - fluid filled blisters
Golden yellow crust - can indicate staph aureus
Most common causes of cellulitis
Staphylococcus aureus
Group A STREPTOCOCCIS
Group C Sterptococcus
(MRSA)
Most common causes of cellulitis
Staphylococcus aureus
Group A STREPTOCOCCIS
Group C Sterptococcus
(MRSA)
Antibiotics of choice in cellulitis
Flucloxacillin
Clarithromycin
Clindamycin
Co-amoxiclav
Who should get influenza vaccine
Aged >65
Young children
Pregnant women
Chronic health conditions - asthma, COPD, HF, Diabetes
Healthcare workers and carers
Most common cause of bacterial meningitis
Neisseria meningitidis (meningococcus)
Streptococcus pneumoniae (pneumococcus)
Neonates - Group B strep
Management of bacterial meningitis in the community
IM benzylpenicillin
<1 year - 300mg
1-9 years - 600mg
>10 years - 1200mg
Send to hospital!
Management of bacterial meningitis in hospital
<3 months - cefotaxime plus amoxicillin
>3 months - ceftriaxone
Steroids reduce the frequency of hearing loss - dexamethasone
What should close contacts of bacterial meningitis receive
Post exposure prophylaxis - prolonged contact within prior 7 days
Single doe ciprofloxacin
Most common cause of viral meningitis
Herpes simplex virus
Entero virus
Varicella zoster virus
What would the CSF sample show in bacterial meningitis
Appearance - cloudy
Protein - high
Glucose - low
WCC - High (neuts)
Culture - bacterial growth
What would the CSF sample show in viral meningitis
Appearance - clear
Protein - mildly raised or normal
Glucose - normal
WCC - high (lymphocytes)
Culture - negative
What colour does mycobacterium tuberculosis turn under what stain.
Bright red un Zeihl-Neelsen stain
What test can be used to identify previous immune response to TB
Mantoux test
Management of acute pulmonary TB
RIPE
Rifampicin - 6 months
Isoniazid - 6 months
Pyrazinamide - 2 months
Ethambutol - 2 months
What should be additionally prescribed alongside isoniazid
Pyridoxine - vit B6
Causes peripheral neuropathy
Side effects of rifampacin
Changes colour of secretions red
P450 induce!
Side effects of isoniazid
Peripheral neuropathy - pyridoxine
Side effects of pyrazinamide
Hyperuricaemia - gout!
Side effects of ethambutol
Colour blindness and reduced visual acuity
Define HIv
Human immunodeficiency virus
Define AIDS
Acquired immunodeficiency syndrome
Examples of AIDS defining illnesses
Associated with end stage HIV - low CD4 count allows atypical infection
Kaposi’s sarcoma
Pneumocystis jirovecii penumonia
Cytomegalovirus infection
Candidiasis
Lymphomas
Tuberculosis
Examples of AIDS defining illnesses
Associated with end stage HIV - low CD4 count allows atypical infection
Kaposi’s sarcoma
Pneumocystis jirovecii penumonia
Cytomegalovirus infection
Candidiasis
Lymphomas
Tuberculosis
Examples of AIDS defining illnesses
Associated with end stage HIV - low CD4 count allows atypical infection
Kaposi’s sarcoma
Pneumocystis jirovecii penumonia
Cytomegalovirus infection
Candidiasis
Lymphomas
Tuberculosis
Management of HIV
Highly active anti-retrovirus therapy (HAART)
Protease inhibitors
Integrase inhibitors
Nucleoside reverse transcriptase inhibitors
Non-nucleoside reverse transcriptase inhibitors
Entry inhibitors
When can PEP be started
Less than 72 hours post exposure
Most common cause of malaria
Plasmodium falciparum - also most sever
