Fatal Infection with a Novel, Unidentified Mycobacterium in a Man with the Acquired Immunodeficiency Syndrome

Systematic 16S rRNA Gene Sequencing of Atypical Clinical Isolates Identified 27 New Bacterial Species Associated with Humans

“…Sixteen species were obtained from humans for the first time. Our results show the important role that 16S rRNA gene sequence-based bacterial identification currently plays in recognizing unusual and emerging bacterial diseases.16S rRNA gene sequencing (39) was first proposed to identify uncultured microorganisms (17,25,38), but the idea that it could be used for bacterial identification of cultured bacteria in clinical laboratories has become increasingly realistic (7,8,34,36), and the technique is now commercially available (6,34,35).Identification of organisms by 16S rRNA gene sequencing has been described in case reports and in reports focusing on a particular bacterial phylum or genus, such as Mycobacterium (6, 36), Actinomyces (15, 28), aerobic gram-negative bacilli (8, 34), coryneform bacteria (35), and aerobic gram-positive rods (3), and we previously reported a series including both environmental and clinical isolates (7).Although 16S rRNA gene sequence analysis has become a common method for the accurate identification of bacterial isolates (24), and its definition of bacterial species has been precise (30), the impact of systematic sequencing of unidentified bacteria in a clinical laboratory setting has seldom been evaluated (3). 16S rRNA gene sequence-based descriptions of new taxa are still a matter of debate (19).…”

Disseminated Mycobacterium genavense Infection in Two Patients with AIDS

“…Hirschel et al [1] documented bacteria within the cytoplasm of histiocytes in pathology specimens and demonstrated growth of bacteria in vitro within mouse peritoneal macrophages. Because of the prominence of gastrointestinal disease, it has been suggested that infection is acquired via an oral route [1]. Although most cases of M. genavenseinfection in patients with AIDS identified to date have occurred in central Europe, the geographic range of the organism is unknown.…”

“…This growth may require months of incubation. Recently, Bottger et al genavense infection has ranged from 2 months to > 14 months [1,3]. One ofour patients had little or no response to therapy and died after 5 months (death was caused by another opportunistic infection).…”

“…Disseminated mycobacterial disease in the late stages of AIDS is most commonly the result of infection with Mycobacterium avium complex (MAC). Despite multidrug therapy, most patients' clinical conditions improve only minimally.In 1990 Hirschel et al [1] reported the case of a patient with advanced AIDS who developed a syndrome characterized by fever, anorexia, diarrhea, and weight loss. Staining of biopsies of duodenum and bone marrow and blood buffy coat samples revealed acid-fast bacilli (AFB), which grew in liquid BACTEC medium but not on a variety of solid media.…”

“…In 1990 Hirschel et al [1] reported the case of a patient with advanced AIDS who developed a syndrome characterized by fever, anorexia, diarrhea, and weight loss. Staining of biopsies of duodenum and bone marrow and blood buffy coat samples revealed acid-fast bacilli (AFB), which grew in liquid BACTEC medium but not on a variety of solid media.…”