Mycobacteria

Question 1

Pt with suspected MAC.

Which antibiotics to test susceptibility for?

Answer 1

Clarithromycin

Amikacin

Question 2

Pt with suspected M.kansasii.

Which antibiotics to test susceptibility for?

Answer 2

Clarithromycin

Amikacin

Rifampicin

Question 3

Patient with M.abcessus.

Which antibiotics to test susceptibility for?

Answer 3

clarithromycin

amikacin

cefoxitin

(also think cotrim)

Question 4

Name 3 fast growing mycobacteria (<7 days)

Answer 4

China Absolute Fortune

M.chelonae

M.abcessus

M.fortuitum

Question 5

Name 2 Intermediate-growing mycobacteria

Answer 5

FISH in GORGE

M.marinum

M.gordonae

Question 6

Sputum from patient grew MAC clari-sensitive.

How to treat this LRTI?

Answer 6

MacClaREt

clarithromycin

rifampicin

ethambutol

for 12 months

(If severe MAC pulmonary disease=consider injectable amikacin/streptomycin)

Question 7

How to treat pulmonary MAC (clari-resistant)?

Answer 7

MacIsaREt

Isoniazid/quinolone

Rifampicin

Ethambutol

Consider injectable aminoglycoside

(may use nebulised amikacin if injectable hard)

Question 8

Patient with pulmonary MAC. How long to treat?

Answer 8

12 months since culture conversion

Question 9

Rifampicin-sensitive Pulmonary M.kansasii. How to treat?

Answer 9

REI or REC

• Rifampicin, ethambutol, isoniazid
• Rifampicin, ethambutol, clarithromycin

Question 10

Rifampicin-resistant Pulmonary M.kansasii.

How to treat?

Answer 10

3 drug regime guided by susceptibility

Question 11

How to treat pulmonary M.malmonsae?

Answer 11

as per MAC.

(MACClaREt)

• clarithromycin
• Rifampicin

Ethambutol

consider injectable aminoglycoside if severe

Duration: min 12 months after culture conversion

Question 12

Pulmonary M.xenopii. How to treat?

Answer 12

4 drug regime:

• rifampicin
• clarithromycin
• ethambutol
• isoniazid/quinolone

+ if severe, consider injectable aminoglycoside

Question 13

Man listed for lung transplant but found to have NTM pulmonary disease.

Can he remain on transplant list?

Answer 13

Yes.

Isolation of NTM organisms including M. abscessus in potential lung transplant candidates should not preclude referral and assessment for lung transplantation.

But counsel patient about increased risk of disseminated NTM disease needing long duration on multi-antibiotic treatment.

Question 14

Pulmonary M.abscessus. How to treat?

Answer 14

Induction phase and maintenance phase

• Induction: MIN 4 weeks iv imipenem, iv tigecycline, iv amikacin+-Po clari

(no po clari if constitutive macrolide resistance). if inducible macrolide resistance, still worth trying clari.

If constitutive macrolide resistance, just give the first 3 iv drugs.

• Maintenance: nebulised amikacin+Po clari and EITHER iv clofazimine/linezolid/ minocycline or doxycycline/moxifloxacin or ciprofloxacin/co-trimoxazole
• If constitutive macrolide resistance, then nebulised amikacin and 2 of above.

Question 15

Monitoring patients on treatment for pulmonary NTM.

How to monitor?

Answer 15

• CT Chest at pre- and end of treatment to assess response
• send sputum every 4-12 weeks during treatment upto 12months after completing treatment to assess microbiological response
• for pts on aminoglycosides, measure levels and creatinine. do audiometry at beginning and intermittently.
• If starting ethambutol, check visual acuity and colour vision prior to starting. if patient has renal impairment, measure ethambutol levels.

Question 16

Which NTM prefer colder temperatures?

Answer 16

M.marinum, M.chelonae, M.haemophilum

Question 17

Which mycobacteria loves iron?

Answer 17

M.haemophilum

Question 18

Which mycobacteria grows better at warmer temperatures (T 42’C)?

Answer 18

M.xenopi

Question 19

Systemically well pt had solitary NTM nodule resected. What FU treatment does he need?

Answer 19

None.

Following resection of a solitary NTM nodule in an individual with no other features of NTM-pulmonary disease, antibiotic treatment is not usually required.

Question 20

symptomatic NTM pt with refractory disease. What’s the role of surgery? What’s the role of antibiotics?

Answer 20

May have lung surgery. need to be established on antibiotics prior to surgery and continue 12 months after culture conversion even if surgery done.