ID Flashcards
Gram +ve cocci
Staphylococcus
Streptococcus
Enterococcus
Gram +ve rods
Use the mnemonic “corney Mike’s list of basic cars”:
Corney – Corneybacteria
Mike’s – Mycobacteria
List of – Listeria
Basic – Bacillus
Cars – Nocardia
Gram +ve anaerobes
Use the mnemonic “CLAP”:
C – Clostridium
L – Lactobacillus
A – Actinomyces
P – Propionibacterium
Gram -ve
Neisseria meningitis
Neisseria gonorrhoea
Haemophilia influenza
E. coli
Klebsiella
Pseudomonas aeruginosa
Moraxella catarrhalis
Atypical bacteria
The definition of atypical bacteria is that they cannot be cultured in the normal way or detected using a gram stain. Atypical bacteria are most often implicated in pneumonia.
The atypical bacteria that cause atypical pneumonia can be remembered using the mnemonic “legions of psittaci MCQs”:
Legions – Legionella pneumophila
Psittaci – Chlamydia psittaci
M – Mycoplasma pneumoniae
C – Chlamydydophila pneumoniae
Qs – Q fever (coxiella burneti)
Management- Macrolides such as clarithromycin
Quinolones such as levofloxacin
Tetracyclines such as doxycycline
Atypical bacteria
The definition of atypical bacteria is that they cannot be cultured in the normal way or detected using a gram stain. Atypical bacteria are most often implicated in pneumonia.
The atypical bacteria that cause atypical pneumonia can be remembered using the mnemonic “legions of psittaci MCQs”:
Legions – Legionella pneumophila
Psittaci – Chlamydia psittaci
M – Mycoplasma pneumoniae
C – Chlamydydophila pneumoniae
Qs – Q fever (coxiella burneti)
MRSA
Resistant to penicillins, cephalosporins and carbapenems.
People are often colonised with MRSA bacteria (skin and respiratory tract)
If these bacteria become part of an infection they can be difficult to treat.
Patients being admitted for surgery or treatment are screened for MRSA infection by taking nasal and groin swabs- eradication (when on the skin surface and not part of an infection)- chlorhexidine body washes and mupirocin (antibacterial) nasal creams.
Antibiotic treatment options for MRSA infection are:
1st line: vancomycin/ teicoplanin
2nd line: linezolid (inc. allergy)
Extended Spectrum Beta Lactamase bacteria (ESBLs)
bacteria that have developed resistance to beta-lactam antibiotics
usually e. coli or klebsiella and typically cause urinary tract infections (or pneumonia)
NB- sensitive to carbapenems eg. meropenem
Local resistance and guidelines
In your OSCEs questions about treating infections can always be answered with “treat with antibiotics as per the local antibiotic policy”.
Chest infection
Either bacterial pneumonia or viral bronchitis (no ABX)
Bacterial causes;
Streptococcus pneumoniae
Haemophilus influenzae
Moraxella catarrhalis (immunocompromised or pulmonary disease)
Pseudomonas aeruginosa (CF/bronchiectasis)
Staphylococcus aureus (CF)
ABX- Amoxicillin, Erythromycin / clarithromycin, or Doxycycline
Cellulitis
Deeper skin infection caused by staph aureus and strep pyogenes
Erythema (red discolouration)
Warm or hot to touch
Tense
Thickened
Oedematous
Edges are NOT well-demarcated
Bullae (fluid-filled blisters)
A golden-yellow crust can be present and indicate a staphylococcus aureus infection
Eron Classification
Class 1 – no systemic toxicity or comorbidity
Class 2 – systemic toxicity or comorbidity
Class 3 – significant systemic toxicity or significant comorbidity
Class 4 – sepsis or life-threatening
Admit the patient for intravenous antibiotics if they are class 3 or 4. Also consider admission for frail, very young or immunocompromised patients.
Flucloxacillin is first line for mild-moderate
Clarithromycin, erythromycin (in pregnancy) or doxycyline is recommended in patients allergic to penicillin.
Severe cellulitis- co-amoxiclav, cefuroxime, clindamycin or ceftriaxone. (3 C’s)
NB- diagnosis of cellulitis is clinical
Influenza (flu) features
Fever
Coryzal symptoms
Lethargy and fatigue
Anorexia (loss of appetite)
Muscle and joint aches
Headache
Dry cough
Sore throat
NB- secondary pneumonia: usually caused by Staphylococcus aureus
NB- viral nose and throat PCR swabs
Management of influenza
Conservative- notify public health England, rest, fluids, limit contact with other people
Medical- antivirals if the person it as risk of developing severe complications
NB- post exposure prophylaxis, PPE to be worn by hospital staff etc.
HIV seroconversion
HIV seroconversion typically presents as a glandular fever type illness. It usually occurs 3-12 weeks after infection;
sore throat
lymphadenopathy
malaise, myalgia, arthralgia
diarrhoea
maculopapular rash
mouth ulcers
rarely meningoencephalitis
AIDS defining illnesses
AIDS-defining illnesses are associated with end-stage HIV infection where the CD4 count has dropped to a level that allows for unusual opportunistic infections and malignancies to appear;
Kaposi’s sarcoma
Pneumocystis jirovecii pneumonia (PCP)
Cytomegalovirus infection
Candidiasis (oesophageal or bronchial)
Lymphomas
Tuberculosis
Toxoplasmosis
HIV transmission
Unprotected anal, vaginal or oral sexual activity.
Mother to child at any stage of pregnancy, birth or breastfeeding. This is referred to as vertical transmission.
Mucous membrane, blood or open wound exposure to infected blood or bodily fluids such as through sharing needles, needle-stick injuries or blood splashed in an eye.
HIV Investigations
Combination test- HIV p24 antigen and HIV antibody
PCR for HIV RNA (viral load)
NB- testing should be done 4 weeks after possible exposure in asymptomatic patients
HIV Management
Conservative- refer to GUM/ID, regular monitoring, annual cervical smears for women
Medical- ARV (x3), prophylactic antifungals of necessary , CVD therapy
Specialist- reproductive health, PEP etc.
HIV Monitoring
CD4 count (500-1200, below 200= AIDS)
Viral load
NB- aim is to have a normal CD4 count with undetectable viral load
Reproductive health
Can engage in protective sex (barrier method)
Caesarean section unless undetectable viral load
Children born to HIV+ve mothers get ART for 4 weeks after birth
Can breast feed if undetectable load, but there is still a risk of transmission
Oesophageal candidiasis
the most common cause of oesophagitis in patients with HIV. It is generally seen in patients with a CD4 count of less than 100. Typical symptoms include dysphagia and odynophagia. Fluconazole and itraconazole are first-line treatments.
Kaposi’s sarcoma
caused by HHV-8 (human herpes virus 8)
presents as purple papules or plaques on the skin or mucosa (e.g. gastrointestinal and respiratory tract)
skin lesions may later ulcerate
respiratory involvement may cause massive haemoptysis and pleural effusion
radiotherapy + resection
Pneumocystis jirovecii
the most common opportunistic infection in AIDS
all patients with a CD4 count < 200/mm³ should receive PCP prophylaxis
Management- co-trimoxazole, IV pentamidine in severe cases
Pneumocystis jirovecii
the most common opportunistic infection in AIDS
all patients with a CD4 count < 200/mm³ should receive PCP prophylaxis
Management- co-trimoxazole, IV pentamidine in severe cases
Features (PJ pneumonia);
dyspnoea
dry cough
fever
causes desaturation on exercise
clear chest on examination/ few chest signs
Management of animal and human bites
Cleanse wound (puncture wounds should not be sutured closed unless cosmesis is at risk)
Co-amoxiclav
Anthrax
causes painless black eschar (cutaneous ‘malignant pustule’, but no pus)
typically painless and non-tender
may cause marked oedema
anthrax can cause gastrointestinal bleeding
Antibiotic guidelines pass medicine
print out (maybe I already have them printed?)
Aspergilloma
a mycetoma (mass-like fungus ball) which often colonises an existing lung cavity (e.g. secondary to tuberculosis, lung cancer or cystic fibrosis).
Usually asymptomatic but features may include
-cough
-haemoptysis (may be severe)
Can be seen on CXR/ CT scan
Bed bugs
Intensely itchy bumps on arms legs and torso
Management- wash bed linin, mattress cover, fumigate house
Botulism (clostridium botulinum)
produces botulinum toxin, a neurotoxin which irreversibly blocks the release of acetylcholine
may result from eating contaminated food (e.g. tinned) or intravenous drug use
neurotoxin often affects bulbar muscles and autonomic nervous system
Features;
patient usually fully conscious with no sensory disturbance
flaccid paralysis
diplopia
ataxia
bulbar palsy
NB- antitoxin is the only effective management
Catch scratch disease
Bartonella henselae
Features
fever
history of a cat scratch
regional lymphadenopathy
headache, malaise
Chickenpox exposure
Patients who are immunocompromised should receive chicken pox antibodies if they are exposed and have no antibodies to varicella