Mycobacterium interjectum, a new species isolated from a patient with chronic lymphadenitis

Abstract

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.

Cervical lymphadenitis due to mycobacterium interjectum

“…M. interjectum was described in 1993 in a child of 18 months with chronic cervical lymphadenitis. 1 The phenotypical and biochemical characteristics are similar to those described in M. scrofulaceum, but after carrying out genetic testing it can be seen that our strain is a new species of mycobacteria. 1,3,4 Macroscopic growth in Löwenstein-Jensen agar is dysgonic, scotochromogenic and small at 358C.…”

“…The isolated species are frequently identified as M. avium, M. scrofulaceum, and M. malmoense; they often cause indolent cervical adenitis and the treatment of choice is radical excision. [1][2][3][4] In recent times, new mycobacteria species have been described: M. lentiflavum, M. interjectum, which cause lymphadenitis in children as in the case presented here. [1][2][3][4][5][6] A 2-year-old boy presented with a 3-month history of a 2 Â 2 cm submandibular adenopathy in the right cervical area, which did not remit with antibiotic treatment (amoxicillin-clavulanate).…”

“…[1][2][3][4] In recent times, new mycobacteria species have been described: M. lentiflavum, M. interjectum, which cause lymphadenitis in children as in the case presented here. [1][2][3][4][5][6] A 2-year-old boy presented with a 3-month history of a 2 Â 2 cm submandibular adenopathy in the right cervical area, which did not remit with antibiotic treatment (amoxicillin-clavulanate). On examination, a tumor was found in the right submandibular region, which was indolent, fluctuant, inflamed and with a high temperature.The patient had not received a BCG vaccination and tested positive (14 mm) on the PPD RT-23 2 TU Mantoux tuberculin test.…”

“…1 The phenotypical and biochemical characteristics are similar to those described in M. scrofulaceum, but after carrying out genetic testing it can be seen that our strain is a new species of mycobacteria. 1,3,4 Macroscopic growth in Löwenstein-Jensen agar is dysgonic, scotochromogenic and small at 358C. The mycobacteria expresses multidrug resistance in vitro,…”

Non‐tuberculous mycobacterial skin infections

“…Comparative 16 s rDNA sequencing showed that these isolates represent a new slow-growing Mvcobacterium sp. which is named M. interjectum [117].…”