Table 3 Distribution of minimal inhibitory concentration (MIC) for tylosin, tilmicosin, and enrofloxacin among 50 M.gallisepticum field strains, determined by the microbroth dilution method.

Antimicrobial agent

≤0.0032

0.0063

0.0125

0.025

0.05

0.1

0.25

0.63

1.25

2.5

5

≥10

MIC ₅₀

MIC ₉₀

% Resistance

Tylosin

1

11

10

2

1

3

8

13

1

0.05

2.5

50

Tilmicosin

16

6

2

1

3

7

15

0.1

≥10

50

Enrofloxacin*

3

10

9

5

2

11

8

2

0.25

5

46