Mycobacterium avium Complex (MAC)

Author(s):  
Edward C. Rosenow

• M avium and M intracellulare are genetically so similar that they are considered the same organism (ie, MAC [M avium complex, formerly Mycobacterium avium-intracellulare, or MAIC]) • MAC is most common mycobacterial organism cultured and one of most common of all organisms cultured •...

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4980-4980
Author(s):  
Nayf Edrees ◽  
Thomas H. Howard

Abstract Nontuberculous mycobacteria (NTM) are ubiquitous free living soil and water– borne organisms that cause numerous clinical syndromes including lymphadenitis, skin, soft tissue and pulmonary infections, however disseminated infection is almost exclusively in patient with severe immunocompromise (i.e:HIV, Hematological malignancy, and bone marrow transplant). Mycobacterium avium complex (MAC) is hard to diagnose as it is considered slow grower NTM. We describe a case of disseminated Mycobacterium avium-intracellulare complex infection in teenager with sickle hemoglobinopathy with unique presentation mimicking pRBCs transfusion reaction. Patient presented on three different occasions with tachycardia, hypotension and fever within 2-24 hours following pRBCs pheresis, all three episodes were investigated and were negative for transfusion reactions. Patient had central venous catheter (CVC), frequent admissions for vaso-occlusive painful episode, on hydrocortisone for adrenal insufficiency and off Hydroxyurea for two months. Diagnosis of mycobacterium avium complex bacteremia was confirmed by two positive blood cultures, whole body CT scan showed liver nodules, spleen nodules and lung nodules. Pulmonary dissemination was confirmed by Biopsy and culture, Lymphocyte markers showed severe lymphopenia with absolute CD4 count of 64. Patient underwent treatment with three month of four antibiotics followed by 9 months of three antibiotics with removal of the central line, follow up scan showed decrease size and numbers of nodules, patient started tolerating pheresis within one month of the antibiotics initiation. NTM infection should be added to the list of pathogens in sickle cell patients with CVCs and fever and should be considered in frequent pRBC transfusion like reaction with negative workup. Routine blood culture can identify rapid growing NTM but specific mycobacterial blood culture is required in case of other NTM species (slow grower). As dissemination almost always occurs in those with impaired cellular immunity, HIV testing and lymphocyte markers should be performed Removal of involved CVCs is essential for the treatment as well as appropriate antimicrobial medications. Disclosures No relevant conflicts of interest to declare.


1996 ◽  
Vol 7 (1_suppl) ◽  
pp. 23-27 ◽  
Author(s):  
L S Young

The most common pathogens involved in disseminated bacterial infection in people with acquired immunodeficiency syndrome (AIDS) are organisms of the Mycobacterium avium-intracellulare complex (MAC). Azithromycin and clarithromycin, a new azalide and macrolide, respectively, are among the most potent monotherapies for MAC bacteraemia, although many bloodstream isolates demonstrate increased minimum inhibitory concentrations after 4 months of treatment. Current recommended prophylaxis, based on the results of two randomized, double-blind, prospective studies, is rifabutin 300 mg daily for people with AIDS with <100 CD4 lymphocytes/mm3. In the beige mouse model, we have shown that both azithromycin and clarithromycin prevent MAC bacteraemia following repetitive oral challenge. Clinical trials are now underway to confirm these effects in man; comparative treatments include placebo, rifabutin and an azalide/macrolide plus rifabutin. While combinations might be more effective and reduce the emergence of resistance, the spectre of cytochrome P-450 drug interactions necessitates careful study before combination prophylactic approaches are accepted. Such interactions are associated with rifabutin and some macrolides, although azithromycin may be less problematic in this respect as it appears to have little potential to interact with other antimicrobial agents.


2017 ◽  
Vol 4 (2) ◽  
pp. 42
Author(s):  
Pradeep Kumar Kumar Mada ◽  
Smitha Maruvada ◽  
Andrew Stevenson Joel Chandranesan

In the United States, the most common non-tuberculous species causing human diseases are slowly growing species; Mycobacterium avium complex (MAC) and Mycobacterium kansasii and rapidly growing species; Mycobacterium abscessus. With the advent of highly active antiretroviral therapy and MAC prophylaxis, disseminated MAC disease is seen infrequently. We report a case of 33-Year-old HIV (Human Immunodeficiency Virus), non-compliant patient presented with disseminated MAC disease. Sputum AFB smear, culture, and Bone marrow biopsy revealed Mycobacterium Avium Intracellulare by DNA (Deoxyribonucleic acid) probe. Following confirmation, he was initiated on Clarithromycin, Ethambutol and Rifabutin for one year of duration with follow up as outpatient.


2021 ◽  
Vol 13 (2) ◽  
pp. 454-464
Author(s):  
Sanu Rajendraprasad ◽  
Christopher Destache ◽  
David Quimby

Nontuberculous mycobacterial (NTM) genitourinary (GU) infections are relatively rare, and there is frequently a delay in diagnosis. Mycobacterium avium-intracellulare complex (MAC) cases seem to be less frequent than other NTM as a cause of these infections. In addition, there are no set treatment guidelines for these organisms in the GU tract. Given the limitations of data this review summarizes a case presentation of this infection and the literature available on the topic. Many different antimicrobial regimens and durations have been used in the published literature. While the infrequency of these infections suggests that there will not be randomized controlled trials to determine optimal therapy, our case suggests that a brief course of amikacin may play a useful role in those who cannot tolerate other antibiotics.


2020 ◽  
Author(s):  
Juliana Rotter ◽  
Christopher S. Graffeo ◽  
Hannah E. Gilder ◽  
Lucas P. Carlstrom ◽  
Avital Perry ◽  
...  

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