Mycobacterial disease Flashcards
What are some slow growing Mycobacteria?
MTB complex such as M bovis BCG and M tuberculosis
M avium complex. such as M avium and M intracellulare
What are some rapid growing mycobacteria?
M abscessus complex - Affects CF and bronchiectasis patients
What do mycobacteria look like?
Non motile rod shaped
Slow growing
How to we stain for mycobacteria?
Auramine - Immuniflorescence
Ziehl Neissan
Where can non TB mycobacteria (NTM) be found
Water
Soil
They form biofilms
What are some slow growing NTM and which places do they invade?
Mycobacterium chimera - Cardiothoracic procedures
Mycobacterium marinum - Swimming pool granuloma
Mycobacterium ulcerans - Skin lesions such as bairnsdale and buruli ulcers
What are some rapid growing NTM?
M abscessus and M chelonae and M fortuitum
Seen in tattoo infections, CF and bronchiectasis
How tp diagnose NTM?
Positive culture > 1 sputum sample OR \+ve BAL OR \+ve biopsy with granulomata
How is NTM treated?
Macrolides - Clarithromycin/Azithromycin, rifampicin, ethambutol, amikacin/streptomycin
Combination therapy
Need to do susceptibility testing
Or surgical removal
What are the 2 ways Mycobacterium leprae / lepresy present?
Low count of basili - Paucibacillary tb
Mutlibacillary lepromatous
What is someone’s life time risl of developing TB if they have close contact of a person with pulmonary TB?
10%
What are the symptoms primary TB?
Ghon focus/complex
Erythema nodosum
May be disseminated/milliary
What are the chances of latent TB resurfacing?
10%
What can you see in a cxr of pulmonary tb?
Caseating granulomas - Commonly in upper lobe
Mediastinal LNs
What are some extra pulmonary lymphadenopathy symptoms of TB?
\Scrofula is the most common form
Cervical lymph nodes are most commonly involved
Abscesses and sinuses can be formed
This is also a common presentation of BCGitis (occurs when children are given the BCG vaccination and they cannot control the BCG immunisation, thus having a certain degree of involvement of lymph nodes)
What are some extra pulmonary gastro symptoms of TB?
Used to be very common in the past
People would get this before milk was pasteurised and contained M. bovis
Swallowing of tubercules
What are some extra pulmonary genitourinary symptoms of TB?
Slow progression to renal disease
Used to be reported as a ‘mastic kidney’- a white kidney characterised mainly by extensive necrosis
Usually one of the kidneys is severely affected before this is diagnosed
Subsequent spreading to lower urinary tract
What are some extra pulmonary peritoneal symptoms of TB?
Ascitic or adhesive
Can cause very severe and damaging presentations e.g. can cause severe fibrosis of the pericardium and of the abdomen
What are some extra pulmonary bone and joint symptoms of TB?
Haematogenous spread
Spinal TB most common- particularly affects the thoracic spine
Pott’s disease
What are some extra pulmonary miliary symptoms of TB?
Millet seeds on CXR
Progressively disseminated haematogenous TB
Increased due to HIV
What are some extra pulmonary CNS symptoms of TB?
TB meningitis
What
Haematogenous spread
What investigations would you do for TB?
CXR
Sputum x 3 otherwise bronchoscopy
Biopsy
Send all of that to AAFB smear
Culture - Gold standard as you can do sensitivity test
PCR - Can tell rifampicin resistance
Histology
Latent TB - Mantoux skin test and IGRAs
What is the treatment for TB?
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
All of those for 2 months
Then 4 months of Rifampicin and Isoniazid
What are the side effects of rifampicin
Orange secretions
Raised transaminases
Induces P450 enzymes
What are the side effects of Isoniazid
Peripheral neuropathy - Pyridoxine 10mg od
Hepatotoxicity
What are the side effects of pyrazinamide
Hepatotoxicity
What are the side effects of ethambutol?
Visual disturbances
