Strains of a new type of slowly growing mycobacterium were repeatedly isolated from sputum h m a patient with pulmonary disease. This photochromogenic organism grew at 22, 31, 37, and 41"C, possessed catalase, acid phosphatase, esterase, P-galactosidase, and arylsulfatase activities, and hydrolyzed Tween. It did not produce nicotinic acid or have nitrate reductase, acetamidase, benzamidase, isonicotinamidase, nicotinamidase, pyrazinamidase, succinidamidase, and acid phosphatase activities. Urease activity was variable. The organism is susceptible to ethambutol and resistant to isoniazid and streptomycin. A mycolic acid analysis revealed the presence of a-mycolates, a'-mycolates, and keto-mycolates. The results of comparative 16s rRNA sequencing placed this organism at an intermediate position between the rapidly and slowly growing mycobacteria. On the basis of the pattern of enzymatic activities and metabolic properties, the results of fatty acid analyses, and the unique 16s rRNA sequence, we propose that this organism represents a new species, for which we propose the name Mycobacterium intermedium. The type strain is strain 1669/91; a culture of this strain has been deposited in the Deutsche Sammlung von Mikroorganismen und Zellkulturen as strain DSM 44049.Mycobacteria are aerobic, nonmobile bacteria that are characteristically acid fast. The property of acid fastness, which is due to waxy materials in the cell wall, is particularly important for recognizing mycobacteria. Members of the genus Mycobacterium are widespread in nature and range €rom soil-dwelling saprophytes to pathogens of humans and animals (26,32). Isolates belonging to a previously unrecognized Mycobacterium species were isolated repeatedly from sputum from a patient with pulmonary disease. In this paper we describe the results of a taxonomic study of this organism and propose that it should be named Mycobacterium inter-.medium sp. nov. MATERIALS AND METHODSBacterial strains. Three isolates, strains 8537/90, 1669/91T (T = type strain), and 1924/91, were recovered from sputum specimens obtained from a patient with pulmonary disease. The isolation method used was the standard method used for isolation of mycobacteria from clinical specimens (26). Colony morphology and the ability to grow at various temperatures (22, 31, 37, 41, and 45°C) were determined after 4 weeks of incubation on Liiwenstein-Jensen slants. The other strains used in this study were obtained from the strain collection of the National Reference Laboratory for Mycobacteria, Forschungsinstitut Borstel, Borstel, Germany.Identification. The following properties were determined as described previously (14): production of nicotinic acid (24); acetamidase, benzamidase, urease, isonicotinamidase, nicotinamidase, pyrazinamidase, and succinamidase activities (3); nitrate reduction (4); Tween hydrolysis (31); acid phosphatase activity (9); production of esterases (10) and arylsulfatases (18); catalase activity (15); P-galactosidase activity (12); and resistance to isoniazid (0.25 pg/ml), ...

Strains of a new type of group 111 nonphotochromogenic mycobacteria have been repeatedly isolated from four patients with clinical and roentgenological signs of lung mycobacteriosis. These strains split nicotinamide and pyrazinamide as do those of Mycobacterium avium, but they show no esterase activity. Furthermore, the strains produce thermolabile catalase and hydrolyze Tween 80. They also have a unique lipid pattern and special sensitins and agglutinins. These strains, therefore, are considered as belonging to a new species of pathogenic, nonphotochromogenic mycobacteria, for which we propose the name Mycobacterium malmoense. Strain M-o 816 is the type strain, and it has been deposited in the American Type Culture Collection under the number 29571.During the years 1968 through 1970, seven unusual mycobacterial strains were isolated from four patients from Malmo and Lund, Sweden. All of the strains grew extremely slowly and poorly as tiny colonies. Their properties, as determined at laboratories in Malmo, Sweden, and in Borstel, Germany, indicated that they belonged to a new species. This paper reports the results of a taxonomic study of these strains. MATERIALS AND METHODSBacterial strains. The seven strains of atypical mycobacteria studied (referred to herein as the Malmo strains) and their sources are cited below. Strain M-6 648 was isolated from a needle aspiration of a process in the right lung, and strains M-6 649 and M-o 650 were isolated from gastric lavage and bronchial secretion, respectively, of the patient. Strains M-o 709 and M-o 710 were isolated from gastric lavage and sputum, respectively, from the second patient, who had two more sputum samples which were culture positive. Strain M-o 716 was isolated from the sputum of the third patient, who had four more positive samples. Strain M-o 816 was isolated from resected lung tissue in the fourth patient, who also had positive sputum cultures.The results of earlier studies (11) of strains of Mycobacterium avium, Mycobacteriurn intrace&-lare, and Mycobacterium xenopi were compared with the properties of these new strains.Strain characteristics. Colony morphology and the ability of the strains to grow at various temperatures (22, 31, 37, 39, 43, and 45°C) were observed during 6 weeks of incubation of cultures on Lowenstein-Jensen medium inoculated with mg of mycobacteria per tube.Drug susceptibility testing was performed with Lowenstein-Jensen medium in tubes closed with stoppers which allowed exchange of air. Chemotherapeutic agents were added before inspissation. Tubes containing isoniazid, streptomycin, ethambutol, rifampin, p-aminosalicylic acid, or thiosemicarbazone were inoculated with mg of mycobacteria per tube; those with ethionamide, capreomycin, viomycin, kanamycin, or cycloserine were inoculated with mg per tube. Two control tubes were included in each test series, as were two additional controls, with an inoculum of lo+ mg of bacteria per tube. Cultures were incubated for 4 weeks at 37°C. Strains were reported as resistant if they grew in ...

Mycobacterium-like organisms, isolates 2081/92 and 4185/92, were recovered from a lymph node of a child with chronic lymphadenitis. The growth characteristics, acid-fastness, and mycolic acids of the isolate were consistent with those for Mycobacterium species. The isolates were biochemically distinct from described Mycobacterium species, although they most closely resembled M. scrofulaceum. Comparative 16S rDNA sequencing showed that these isolates represent a new slow-growing Mycobacterium species which is named M. intejectum. Our results demonstrate the importance of 16S rDNA sequencing for recognizing the diversity of species within the genus Mycobacterium. Mycobacteria are aerobic, nonmobile bacteria that are widespread in nature and that range from soil-dwelling saprophytes to pathogens of humans and animals (23, 32). Cervical lymphadenitis is among the most common manifestation of infection with nontuberculous mycobacteria in children. The mycobacteria isolated represent mainly M. avium, M. scrofulaceum, and M. malmoense (8, 33). In this report, we describe a new Mycobacterium species, M.