TABLE 2.

Estimation of mycobacterial density in CFU contained within 1- and 10-μl calibrated loops^a

Mycobacterium species	Strain	Average population (CFU) per loopful of:
		1 μl	10 μl
M. abscessus	19977	1 × 109	2 × 109
M. fortuitum	6841	6 × 108	9 × 108
M. intracellulare	13950	1 × 108	9 × 109
M. kansasii	864	7 × 107	5 × 108
M. senegalense	2301	5 × 108	2 × 109
M. tuberculosis	S-07	5 × 106	3 × 107
	S-09	6 × 106	4 × 107
	S-38	4 × 106	1 × 107

^aEstimates were generated using duplicate serial dilutions of a primary inoculum spread over the surface of 7H11 agar plates and enumerated after the appearance of visible colonies.