Group

Clear zone size (mm)

No. of isolates

Very good producer

≥15

41 (JBST1-JBST8, JBST13, JBST16-JBST19, JBST21-JBST44, JBST49, JBST54, JBST58 and JBST62)

Good producer

≥10

4 (JBST48, JBST53, JBST55 and JBST65)

Weak producer

≥5

9 (JBST9, JBST50-JBST52, JBST56-JBST57, JBST59, JBST60 and JBST63)

Poor producer

<5

8 (JBST11, JBST12, JBST14, JBST15, JBST45, JBST47, JBST61 and JBST64)