120
Myc. avium. The pathogen was identifi ed as Myc. avium from the results of 16S
rDNA sequencing (Janse and Kik 2012 ).
Six isolates, recovered between 1964 and 1982, were recognised as a new subspecies, i.e. Myc. chelonei subsp. piscarium, by Arakawa and Fryer ( 1984 ), although
the name was later withdrawn (Arakawa et al. 1987 ) because of the inability to
distinguish the organisms serologically from other subspecies of Myc. chelonei. The
resurrection of the name Myc. salmoniphilum and its relationship to Myc. chelonei
is an interesting development and may well accommodate those isolates labelled as
Myc. chelonei subsp. piscarium (Whipps et al. 2007 ). Essentially, the testing regime
was quite extensive, but the value of using only six isolates is questionable. Colonies
on Ogawa medium were off-white with a smooth texture.
The fi sh isolates were considered to be related to Myc. chelonei, although somewhat distinct from the current subspecies, i.e. chelonei and abscessus. For example,
the fi sh isolates were unable to grow at 37 °C, produce nicotinamidase or pyrazinamidase and degrade sodium hippurate or produce acid from trehalose, in contrast
to the two validly published subspecies. However, there was an overall phenotypic
Box 3.10: Mycobacterium chelonei subsp. piscarium
These comprise pleomorphic, acid-fast, weakly Gram-positive rods 1–4 × 0.3–
0.6 μm in size. Neither branching nor aerial hyphae have been observed.
Grow occurs at 10 and 30 °C, but not all at 37 °C, weakly in 3 % (w/v) sodium
chloride but not at all in 5 % (w/v) sodium chloride, and on MacConkey agar
and potassium tellurite agar, and in 250 μg/ml of azoguanine, 5 μg/ml of ethambutol, 250 μg/ml of hydroxylamine, 0.1 % (w/v) malachite green, 0.01 %
(w/v) methyl violet, 0.2 % (w/v) picric acid, 0.01 % (w/v) pyronin B, 1 %
(w/v) sodium deoxycholate and 0.1 % (w/v) sodium nitrate, and variably in
0.01 % (w/v) chlorophenol red and 20 μg/ml of sodium azide. Acid phosphatase, aryl sulphatase and catalase are produced, but not acetamidase, benzamidase, isonicotinamidase, nicotinamidase, pyrazinamidase or succinimidase.
p- aminobenzoate, p- aminosalicylate, sodium salicylate and urea are attacked,
but not allantoin, sodium hippurate or Tweens. Acid is produced from glucose
and mannose, but not arabinose, dulcitol, fructose, galactose, inositol, mannitol, rhamnose, sorbitol, sucrose, trehalose or xylose. Neither sodium benzoate, sodium malonate nor sodium oxalate are utilised as the sole source of
carbon, but variable responses may be recorded with sodium citrate, sodium
fumarate and sodium succinate. L-serine and sodium L- glutamate but not
acetamide, benzamide, glucosamine hydrochloride or nicotinamide are utilised as the sole source of carbon and nitrogen. Mycolic acids are present. The
G + C ratio of the DNA is in the range of 61–65 moles %; with an average
value of 63 +/− 1.7 moles % (Arakawa and Fryer 1984 ).
3 Aerobic Gram-Positive Rods and Cocci
Myc. avium. The pathogen was identifi ed as Myc. avium from the results of 16S
rDNA sequencing (Janse and Kik 2012 ).
Six isolates, recovered between 1964 and 1982, were recognised as a new subspecies, i.e. Myc. chelonei subsp. piscarium, by Arakawa and Fryer ( 1984 ), although
the name was later withdrawn (Arakawa et al. 1987 ) because of the inability to
distinguish the organisms serologically from other subspecies of Myc. chelonei. The
resurrection of the name Myc. salmoniphilum and its relationship to Myc. chelonei
is an interesting development and may well accommodate those isolates labelled as
Myc. chelonei subsp. piscarium (Whipps et al. 2007 ). Essentially, the testing regime
was quite extensive, but the value of using only six isolates is questionable. Colonies
on Ogawa medium were off-white with a smooth texture.
The fi sh isolates were considered to be related to Myc. chelonei, although somewhat distinct from the current subspecies, i.e. chelonei and abscessus. For example,
the fi sh isolates were unable to grow at 37 °C, produce nicotinamidase or pyrazinamidase and degrade sodium hippurate or produce acid from trehalose, in contrast
to the two validly published subspecies. However, there was an overall phenotypic
Box 3.10: Mycobacterium chelonei subsp. piscarium
These comprise pleomorphic, acid-fast, weakly Gram-positive rods 1–4 × 0.3–
0.6 μm in size. Neither branching nor aerial hyphae have been observed.
Grow occurs at 10 and 30 °C, but not all at 37 °C, weakly in 3 % (w/v) sodium
chloride but not at all in 5 % (w/v) sodium chloride, and on MacConkey agar
and potassium tellurite agar, and in 250 μg/ml of azoguanine, 5 μg/ml of ethambutol, 250 μg/ml of hydroxylamine, 0.1 % (w/v) malachite green, 0.01 %
(w/v) methyl violet, 0.2 % (w/v) picric acid, 0.01 % (w/v) pyronin B, 1 %
(w/v) sodium deoxycholate and 0.1 % (w/v) sodium nitrate, and variably in
0.01 % (w/v) chlorophenol red and 20 μg/ml of sodium azide. Acid phosphatase, aryl sulphatase and catalase are produced, but not acetamidase, benzamidase, isonicotinamidase, nicotinamidase, pyrazinamidase or succinimidase.
p- aminobenzoate, p- aminosalicylate, sodium salicylate and urea are attacked,
but not allantoin, sodium hippurate or Tweens. Acid is produced from glucose
and mannose, but not arabinose, dulcitol, fructose, galactose, inositol, mannitol, rhamnose, sorbitol, sucrose, trehalose or xylose. Neither sodium benzoate, sodium malonate nor sodium oxalate are utilised as the sole source of
carbon, but variable responses may be recorded with sodium citrate, sodium
fumarate and sodium succinate. L-serine and sodium L- glutamate but not
acetamide, benzamide, glucosamine hydrochloride or nicotinamide are utilised as the sole source of carbon and nitrogen. Mycolic acids are present. The
G + C ratio of the DNA is in the range of 61–65 moles %; with an average
value of 63 +/− 1.7 moles % (Arakawa and Fryer 1984 ).
3 Aerobic Gram-Positive Rods and Cocci