Mycoplasmal & Myobacterial Infections Flashcards
A fraternity house on the SU hill has had several residents complain of fever and cough over the last 3 months. The fever lasts for up to two weeks, but the cough persists for a month or more. Despite feeling ill, most can still attend classes. You order chest CT’s on the most severely ill. What pathogen do you suspect?
Mycoplasma pneumonia, which causes “walking” pneumonia, especially in large, close-knit groups (i.e. fraternities).
What two mycoplasma are common causes of post-partum fever?
Ureaplasma urealyticum and Mycoplasma hominis
A 42 year old male post-op for heart transplant presents with rapidly progressive fever, night sweats, cough, and hemoptysis. Chest CT reveals a collapsed middle lobe. What stain do you order on the ensuing lung biopsy? Why? What type of necrosis might you expect on the pathology report of an ensuing hilar lymph node biopsy?
Acid-fast staining to reveal probably M tuberculosis infection.
Caseous necrosis with miliary nodules. The combination of lung lesion and LN involvement in the Ghon complex.
A retired physician who had spent time in Peru before medical school presents with fever, cough, malaise, night sweats, and hemoptysis. Multiple apical cavities are observed on Chest CT. What is a probable diagnosis?
Secondary/Cavitary tuberculosis decades after the primary, contained infection
A 28 year old female from India presents at your clinic with disfiguring lesions in her extremities. You biopsy one of these lesions and find a smooth epidermis, clear dermis, and subdermal macrophage accumulations. What stain do you order to examine the macrophage contents?
Acid fast staining for lepromatous M leprae.
A 33 year old male from Zambia presents with numbness in his extremities and face. Upon close examination of the skin you notice multiple hypopigmented macules of varying size. A biopsy shows granulomas containing Langhans giant cells. What is your diagnosis?
Tuberculoid M leprae.
Note that the chances of finding actual organisms are small and the symptoms/granulomas may be due to a hyperergic immune response.
Your patient, a 61 year old male with COPD, has gone in for a chest CT due to a chronic cough and increased shortness of breath. The CT shows multiple cavities in the lungs. You suspect tuberculosis, but on ROS, the patient denies fever, night sweats, weight loss, or fatigue. Diagnosis?
Granulomatous MAI (mycobacterium avium-intracellulare) disease.
The cavitating (and caseating on biopsy) pneumonia without the normal TB symptoms (except cough) in an older patient with predisposing lung issues points to MAI complex.
A 41 year old female with advanced AIDS presents with systemic complaints including fever, night sweats, fatigue, and weight loss, but also diarrhea and abdominal pain. What infection secondary to AIDS is most likely in this patient?
Disseminated infection due to MAI (mycobacterium avium-intracellulare) complex.
The difference between AIDS/MAI patients and tuberculosis patients is the lack of pulmonary symptoms (cough) and addition of small bowel symptoms.
What organism related to MAI complex must be included in the differential for chronic granulomatous pulmonary disease in an immunocompetent patient >50 years old?
Mycobacterium kansasii
Low yield atypical mycobacterium
A 3 year old boy presents with swollen submandibular and cervical lymph nodes. The condition persists longer than you are comfortable with and you order a lymph node biopsy, on which you see a localized granulomatous inflammation. You order surgical excision of these nodes infected with what pathogen?
Mycobacterium scrofulaceum
Low yield atypical mycobacterium
A swimming pool cleaner presents with a non-healing nodular skin lesion that he says was initially a cut on a rock in a pool. The biopsy shows pyogenic reaction due to what acid-fast positive pathogen?
Mycobacterium marinum
Low yield atypical mycobacterium
What is the presenting lesion of Mycobacterium ulcerans? In what part of the world?
A solitary, deep, and undermining ulcer on the extremities in Australia, Africa, and New Guinea
(Low yield atypical mycobacterium)
