Clinical Manifestations, Diagnosis, and Treatment of Mycobacterium haemophilum Infections

Abstract

SUMMARY Mycobacterium haemophilum is a slowly growing acid-fast bacillus (AFB) belonging to the group of nontuberculous mycobacteria (NTM) frequently found in environmental habitats, which can colonize and occasionally infect humans and animals. Several findings suggest that water reservoirs are a likely source of M. haemophilum infections. M. haemophilum causes mainly ulcerating skin infections and arthritis in persons who are severely immunocompromised. Disseminated and pulmonary infections occasionally occur. The second at-risk group is otherwise healthy children, who typically develop cervical and perihilar lymphadenitis. A full diagnostic regimen for the optimal detection of M. haemophilum includes acid-fast staining, culturing at two temperatures with iron-supplemented media, and molecular detection. The most preferable molecular assay is a real-time PCR targeting an M. haemophilum -specific internal transcribed spacer (ITS), but another approach is the application of a generic PCR for a mycobacterium-specific fragment with subsequent sequencing to identify M. haemophilum . No standard treatment guidelines are available, but published literature agrees that immunocompromised patients should be treated with multiple antibiotics, tailored to the disease presentation and underlying degree of immune suppression. The outcome of M. haemophilum cervicofacial lymphadenitis in immunocompetent patients favors surgical intervention rather than antibiotic treatment.

First report of cervicofacial lymphadenitis due to Mycobacterium haemophilum in an immunocompromised adult patient

“…Almost all published reports of M. haemophilum so far have been from developed countries [6]. The paucity of reported cases from developing countries could be attributed to the lack of optimal diagnostic facilities such as appropriate culture and molecular methods for identification of this organism.…”

“…However, the target gene most suitable for identification of this mycobacterial species, like for other NTMs, is still unclear [6]. The hsp65 gene has been reported to be more variable than the 16S rRNA gene sequence [12].…”

“…M. haemophilum infections have been previously reported in other patients receiving immunosuppressives after renal transplantation, with skin lesions being the most common clinical presentations [4,5]. Multiple skin lesions tend to occur and can present as erythematous papules, plaques, nodules, necrotic abscesses, or chronic ulcers, which are found most commonly on the extremities [6]. Although extracutaneous infections such as septicaemia, pneumonitis, septic arthritis, osteomyelitis, epididymal abscess, and pyomyositis have been described previously in immunocompromised patients [6,7], this patient presented with cervicofacial lymphadenitis, which has only been reported so far in immunocompetent adults and children [6].…”

“…Multiple skin lesions tend to occur and can present as erythematous papules, plaques, nodules, necrotic abscesses, or chronic ulcers, which are found most commonly on the extremities [6]. Although extracutaneous infections such as septicaemia, pneumonitis, septic arthritis, osteomyelitis, epididymal abscess, and pyomyositis have been described previously in immunocompromised patients [6,7], this patient presented with cervicofacial lymphadenitis, which has only been reported so far in immunocompetent adults and children [6]. Therefore, this case, to the best of our knowledge, is the first report of cervicofacial lymphadenitis caused by this mycobacterial species in an immunocompromised adult.…”

Performance Assessment of the DR. TBDR/NTM IVD Kit for Direct Detection of Mycobacterium tuberculosis Isolates, Including Rifampin-Resistant Isolates, and Nontuberculous Mycobacteria

“…Not all less-common Mycobacterium species that are known to cause various clinical infections are included in the identification list of the DR. TBDR/NTM IVD kit (1,3,9,14). The clinical significance of less-common NTM species, however, is being criticized (5).…”