Mycobacterium haemophilum: Emerging or Underdiagnosed in Brazil?

To the Editor: Mycobacterium haemophilum was first described in 1978 by Sompolinsky et al. (1) as the cause of cutaneous infections in a patient with Hodgkin disease. Since then, fewer than 100 cases have been reported worldwide, mostly among immunocompromised patients (2), although M. haemophilum infection has also been described in immuno-competent patients as the cause of cer-vical, submandibular, and perihilar lymphadenopathy in children and of pulmonary nodules in an adult (3–5). and the United Kingdom, but to date no reports have originated in South America. The most frequent clinical sign of M. haemophilum infection in adults is a skin or joint lesion. Less common sites for isolation of M. haemophilum include the respiratory tract, blood, bone marrow, bone, and central venous catheters (2,6). M. haemophi-lum is unique among Mycobacterium species owing to its special growth requirements: it grows best at 30°C and requires an iron supplement (hemin or ferric ammonium citrate). We report here the characterization of three strains of M. haemophilum isolated from patients living in three states in two distinct regions of Brazil, Rio de Janeiro and São Paulo (southeast region) and Bahia (northeast region). The first strain was detected in Rio de Janeiro in December 2000 from a blood culture of a 67-year-old man who had received a kidney transplant in 1988 at the age of 55 years and was undergoing immunosuppres-sive treatment with prednisolone and mycophenolate mofetil. The second strain was detected in São Paulo in March 2001 in a 43-year-old HIV-seropositive man from a biopsied specimen of a nasal ulcer. A direct acid-fast stain showed many acid-fast bacilli. At time of diagnosis, the patient's CD4+ cell count was 8/mm 3 and his viral load was 290.000 copies/ mL. The third isolate was detected in Bahia in a 30-year-old HIV-seroposi-tive man who had osteomyelitis in an elbow. A direct acid-fast stain showed rare acid-fast bacilli. The isolate from the Rio de Jan-eiro patient grew only in Myco/F Lytic media (Becton Dickinson Microbiology Systems, Sparks, MD) plus blood in primary isolation and subculture; it failed to grow on chocolate agar at 30°C after 6 weeks. The isolates from São Paulo and Bahia showed a slight growth in 12B media on primary isolation ; this growth was likely supported by the iron provided by the biopsied tissue. Subcultures on chocolate agar showed good growth after 2– 3 weeks at 30°C. The isolates did not grow on Middlebrook …