An organism that causes tuberculosis in birds is?

Appeared in: RUHS, Jaipur, PB B.Sc Nursing Entrance-2019

Explanation

Mycobacterium avium, which is the causative agent of tuberculosis in birds.
The name itself is a major clue, as 'avium' is Latin for 'of birds', and the disease is often called avian tuberculosis.
This organism is part of the nontuberculous mycobacteria (NTM) group and is environmentally widespread.

Option A: Mycobacterium tuberculosis is the primary causative agent of tuberculosis in humans, not birds.
Option B: Mycobacterium bovis primarily causes tuberculosis in cattle (bovines).
Option C: Mycobacterium microti, also known as the 'vole bacillus', is a member of the M. tuberculosis complex that causes disease in rodents.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Causative agents of tuberculosis in different species as background academic context rather than a clinical decision trigger.
While M. avium causes TB in birds, its main clinical relevance for nurses is its role in the Mycobacterium avium complex (MAC), a major opportunistic infection.
Nurses must monitor immunocompromised patients, especially those with HIV/AIDS and very low CD4 counts (less than 50 cells/μL), for signs of disseminated MAC infection, such as persistent fever, night sweats, weight loss, and abdominal pain.
Patient education on adhering to prophylactic medication (like azithromycin) is a key nursing intervention to prevent MAC disease in high-risk populations.

How to Approach the Question

This is a factual recall question testing knowledge of microbiology.
First, identify the keywords in the stem: 'organism', 'tuberculosis', and 'birds'.
Next, examine the options, which are all species of Mycobacterium.
Use etymology as a clue. The term 'avium' is derived from Latin 'avis', meaning bird. This strongly suggests a connection to birds.
Recall the primary hosts for the other common mycobacteria to confirm your choice. M. tuberculosis affects humans, and M. bovis affects cattle (bovine).
Based on the direct link between 'avium' and 'avian' (of birds), select Mycobacterium avium as the correct answer.

Concept Tested & Keywords

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E6 Medicine Harrison 22e Part 1 p. 1421-1423

E6 PATHOLOGY QUICK REVIEWBased on Harsh Mohan Textbook of PATHOLOGY p. 172-174

E6 Pathology-Textbook of PATHOLOGYHarsh Mohan Part 1 (1-214) p. 114-116

Practise the full RUHS, Jaipur, PB B.Sc Nursing Entrance-2019

Attempt every question from this paper in a timed mock, then review the full solution for each one.