2.5. Antimicrobial activity assay of isolates
A previously described method was applied to determine the
antagonistic activity of isolates against clinically important human
pathogens [33]. Table 2 lists the indicator pathogens. A total of 2 ml
of overnight cultured bacteria in the MRS broth was filtered using
Nalgene syringe filter units (0.2 mm). A total of 50 mL of filtrates was
then poured into 7 mm diameter wells created in the MuellereHinton
agar plates, which contained the mentioned indicator
pathogens. The clear zone diameter for each isolated strain was
measured and analyzed after 24 h incubation at 37 C. The areola
diameter was an indicator of anti-pathogenic activity. Antagonistic
activity was divided into three groups: strong (diameter 20 mm),
moderate (20 mm < diameter > 10 mm), and weak
(diameter 10 mm)