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. 2017 Dec 21;62(1):e01364-17. doi: 10.1128/AAC.01364-17

TABLE 1.

Mean LRs achieved by alcoholic PI and CHX for all tested M. abscessus strains and a reference S. aureus strain at each exposure time and dilution by quantitative suspension test

Exposure time (s)a Mean LRb at dilution:
 P1c,e P2d,e
1:25 1:50 1:100 1:200 1:400 1:800
S. aureus (ATCC 29213)
    PI
        30 5.08 5.08 3.88 5.08 5.08 4.54 0.170 Ref
        60 4.16 5.09 5.09 4.05 5.09 5.09 0.623
        90 4.32 4.71 5.15 4.68 5.15 5.15 0.667 Ref
        P3 0.665 0.536 0.102 0.572 0.592 0.414
    CHX
        30 2.37 2.21 1.88 1.69 0.49 0.04 0.036 Ref
        60 2.86 3.31 2.63 2.71 1.79 0.34 0.019
        90 3.93 2.90 3.35 4.22 2.25 1.06 0.141 Ref
        P4e 0.382 0.443 0.277 0.208 0.028 0.023
M. abscessus subsp. bolletii (BCRC 16915)
    PI
        30 5.43 5.43 5.43 5.43 5.43 3.89 0.047 1.000
        60 5.37 5.37 4.78 4.46 5.37 5.37 0.553
        90 5.35 5.35 5.35 5.35 4.82 5.35 0.480 1.000
        P3 0.277 0.277 0.423 0.388 0.377 0.129
    CHX
        30 −0.04 −0.03 −0.01 −0.05 0.05 0.01 0.637 0.011
        60 −0.10 −0.12 −0.09 −0.07 −0.04 −0.02 0.208
        90 −0.13 −0.18 −0.10 −0.07 −0.02 −0.07 0.085 0.007
        P4 0.099 0.066 0.204 0.860 0.184 0.459
M. abscessus subsp. abscessus (ATCC 19977)
    PI
        30 4.08 3.62 3.35 3.64 2.71 2.22 0.635 1.000
        60 2.97 4.74 4.10 4.06 3.05 3.35 0.705
        90 2.95 4.15 3.35 4.11 4.12 3.34 0.904 0.495
        P3 0.451 0.616 0.825 0.934 0.563 0.666
    CHX
        30 −0.06 −0.10 −0.17 −0.04 −0.02 −0.01 0.058 0.010
        60 −0.23 −0.13 −0.10 −0.15 −0.10 −0.11 0.448
        90 −0.14 −0.07 −0.12 −0.12 −0.05 −0.07 0.846 0.008
        P4 0.075 0.670 0.497 0.458 0.674 0.151
M. abscessus subsp. massiliense (TPE 101)
    PI
        30 4.08 4.08 3.64 4.08 3.27 3.32 0.776 1.000
        60 3.60 4.04 3.17 3.44 4.04 2.15 0.199
        90 4.07 4.07 4.07 3.15 2.78 2.74 0.300 0.177
        P3 0.385 0.911 0.351 0.617 0.446 0.641
    CHX
        30 −0.04 −0.00 −0.02 −0.12 −0.02 −0.04 0.935 0.011
        60 −0.04 −0.02 −0.03 0.00 −0.06 −0.06 0.986
        90 −0.04 −0.06 0.01 0.02 −0.03 −0.03 0.821 0.010
        P4 0.999 0.792 0.893 0.138 0.795 0.981
a

P3, P values for whether the differences with increasing exposure times are statistically significant for povidone-iodine; P4, P values for whether the differences with increasing exposure times are statistically significant for chlorhexidine.

b

The experiments were conducted three times, and an average (mean) LR was obtained for each test condition. A mean LR of greater than 5 was considered biocidal.

c

P1, P values for whether the differences across the range of dilutions within species are statistically significant.

d

P2, P values for the interspecies comparison (whether the activities of PI or CHX is significantly different between mycobacterial strain and the reference S. aureus strain) at a dilution of 1:25 with exposure times of 30 s and at a dilution of 1:800 with exposure times of 90 s. Ref, reference.

e

P values of <0.05 are in boldface.