Multicenter Evaluation of the BACTEC MGIT 960 System for Recovery of Mycobacteria

DOI: 10.1128/JCM.37.3.748-752.1999

Article Figures & Data

Table 1.

Specimen types and recovery of mycobacteria

Table 2.

Distribution of isolates recovered in each culture system and in combinations of solid and liquid systems

Organism	Total no. (%) of isolates recovered with^a:
Organism	Total, all media	960 + solid media	460 TB + solid media	Total, 960	Total, 460 TB	Total, solid media	960 only	460 TB only	Solid media only
M. tuberculosiscomplex	132 (100)	121 (92)	128 (97)	102 (77)	119 (90)	105 (79)	4 (3)	11 (8)	3 (2)
MAC	172 (100)	160 (93)	136 (79)	147 (86)	123 (72)	106 (62)	36 (21)	12 (5)	3 (2)
MOTT	58 (100)	54 (93)	44 (76)	40 (69)	29 (50)	39 (67)	14 (24)	4 (7)	10 (17)
All	362 (100)	335 (93)	308 (85)	289 (80)	271 (75)	250 (69)	54 (15)	27 (7)	16 (4)

Table 3.

Distribution of isolates recovered in culture system and combinations with contaminated cohorts removed from analysis

Organism	Total no. of isolates, all media	Total no. (%) of isolates recovered with^a:
Organism	Total no. of isolates, all media	960 + solid media	460 TB + solid media	Total, 960	Total, 460 TB	Total, solid media
M. tuberculosiscomplex	118	111 (94)	114 (97)	101 (86)	108 (92)	95 (81)
MAC	160	153 (96)	127 (79)	143 (89)	115 (72)	102 (64)
MOTT	53	49 (92)	41 (77)	37 (70)	28 (53)	36 (68)
All	331	313 (95)	282 (85)	281 (85)	251 (76)	233 (70)

Table 4.

TTD of M. tuberculosis, MAC, and all mycobacteria in BACTEC MGIT 960 and BACTEC 460 TB systems

Culture system	TTD, days (total no. of isolates detected) for:
	M. tuberculosiscomplex		MAC		All mycobacteria
	Nonpaired^a	Paired^b, c	Nonpaired^a	Paired^b, d	Nonpaired^a	Paired^b
BACTEC 960	14.4 (102)	14.4 (92)	10.0 (147)	9.8 (101)	11.8 (289)	11.1 (213)
BACTEC 460	15.2 (119)	13.2 (92)	10.4 (123)	8.4 (101)	12.5 (271)	11.3 (213)

↵a Total for isolates recovered with either BACTEC MGIT 960 or BACTEC 460 TB system.
↵b Total for isolates recovered with both systems.
c P = 0.055, not significant.
d P = 0.001.

Table 5.

TTD of M. tuberculosis for AFB smear-positive and smear-negative isolates in BACTEC 960 and 460 TB systems

Table 6.

Breakthrough contamination rates

System	% of isolates showing breakthrough contamination
System	All sites (n = 3,330)	Site A (n = 558)	Site B (n = 494)	Site C (n = 679)	Site D (n = 628)	Site E (n = 323)	Site F (n = 648)
BACTEC MGIT 960	8.1	9.3	5.4	10.0	14.6	1.8	4.0
BACTEC 460 TB	4.9	5.0	0.6	9.2	7.1	0.9	3.7
Combined solid media	21.1	27.4	0.8	13.2	31.0	5.2	37.8