Mycobacterium septicum
Cultural characteristics
Biochemical characters
Phylum Actinobacteria, Class Actinobacteria, Order Actinomycetales, Suborder Corynebacterineae, Family Mycobacteriaceae, Genus
Mycobacterium septicum Schinsky et al. 2000.

Mycobacterium fortuitum biovar III.
Member of the
Mycobacterium fortuitum complex.
Acid-fast, pleomorphic coccobacilli. Longer filamentous forms are often observed but
spores and capsules are absent. Gram-positive.
Colonies are cerebriform, slightly beige, with an irregular edge and do not produce
aerial hyphae. Growth occurs on Lowenstein-Jensen medium at 35 ºC in less than 7
days, at 28 ºC. Grows on 5% (w/v) NaCl and on MacConkey agar without crystal violet.  
No growth in lysozyme.
The type strain was isolated from the catheter tip of a 2-year-old child with metastatic hepatoblastoma. Other isolates were retrieved
from sputum, peritonitis fluid, and eyelid infection.
Resistant to thiophene-2-hydrazine carboxylic acid (TCH), isoniazid, rifampin, streptomycin, ethambutol, ampicillin, cefamandole,
cefotaxime, ceftriaxone and streptomycin. Susceptible to amikacin, amoxicillin-clavulanate, ciprofloxacin, doxycycline, erythromycin,
imipenem, minocycline, sulfamethoxazole, trimethoprim+sulfamethoxazole, vancomycin, tobramycin, gentamicin, neomycin and
It is the aetiological agent of catheter-related bacteraemia in a 2-year-old child diagnosed with metastatic hepatoblastom. May produce
pulmonary disease or peritoneal dialysis-associated peritonitis.
  1. Schinsky MF, McNeil MM, Whitney AM, Steigerwalt AG, Lasker BA, Floyd MM, Hogg GG, Brenner DJ, Brown JM. Mycobacterium
    septicum sp. nov., a new rapidly growing species associated with catheter-related bacteraemia. Int J Syst Evol Microbiol 2000; 50:
  2. Schinsky MF, Morey RE, Steigerwalt AG, Douglas MP, Wilson RW, Floyd MM, Butler WR, Daneshvar MI, Brown-Elliott BA, Wallace
    RJJ, et al. Taxonomic variation in the Mycobacterium fortuitum third biovariant complex: description of Mycobacterium boenickei
    sp. nov., Mycobacterium houstonense sp. nov., Mycobacterium neworleansense sp. nov. and Mycobacterium brisbanense sp.
    nov. and recognition of Mycobacterium porcinum from human clinical isolates. Int J Syst Evol Microbiol 2004; 54:1653-1667.
  3. Garcia-Agudo, L., Jesus, I., Rodriguez-Iglesias, M., and Garcia-Martos, P. (2011). Evaluation of INNO-LiPA mycobacteria v2 assay
    for identification of rapidly growing mycobacteria. Brazilian journal of microbiology : [publication of the Brazilian Society for
    Microbiology], 42(3), 1220-1226.
  4. Lulu Lian, Jianping Deng, Xiuqin Zhao, Haiyan Dong, Jingrui Zhang, Guilian Li, Tiquan Xiao, Yimou Wu, Qun Li, Kanglin Wan. The
    first case of pulmonary disease caused by Mycobacterium septicum in China. International Journal of Infectious Diseases
    Volume 17, Issue 5, May 2013, Pages e352-e354.
  5. Nattawat Klomjit, Api Chewcharat, Margaret D’Uscio, Andrea G Kattah. Mycobacterium septicum associated peritonitis: A case
    report. Peritoneal Dialysis International 1-3.
  6. Shin, Hyojeong; Song, Jong Keun; Hong, Jeong-geun; Yoo, Gyeol; Baek, Sang Oon; Lee, Jun Yong. Surgical Site Infection Caused
    by Mycobacterium Septicum Following Blepharoplasty, Journal of Craniofacial Surgery: May 2020 - Volume 31 - Issue 3 - p e228-
    e230 doi: 10.1097/SCS.0000000000006096.
  7. John G. Magee and Alan C. Ward 2012. Family III. Mycobacteriaceae Chester 1897, 63AL in Bergey’s Manual of Systematic
    Bacteriology, Volume Five The Actinobacteria, Part A, Michael Goodfellow & al. (editors), 312-375.
  8. Lamy B, Marchandin H, Hamitouche K, Laurent F. Mycobacterium setense sp. nov., a Mycobacterium fortuitum-group organism
    isolated from a patient with soft tissue infection and osteitis. Int J Syst Evol Microbiol 2008; 58:486-490.
Positive results for arylsulfatase (14 days), iron uptake, nitrate reduction, urease, acid production from D-fructose, D-glucose, glycerol,
i-myo-inositol, D-mannitol, D-mannose, salicin, D-trehalose and D-xylose.
Can utilize as sole carbon source i-myo-inositol, D-mannitol, and salicin.

Negative results for acetamidase, Tween 80 hydrolysis.
acid production from adonitol, L-arabinose, cellobiose, dulcitol, i-erythritol, galactose, lactose, maltose, melibiose, raffinose, L-
rhamnose, D-sorbitol, starch, and sucrose.
No utilization of citrate, adonitol, L-arabinose, i-erythritol, inositol, L-rhamnose, and D-sorbitol.

Variable results for arylsulfatase (3 days), utilization of D-galactose, glycerol, sucrose, and D-xylose.
(c) Costin Stoica
Culture media
Biochemical tests
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