Efficiency of Mitis salivarius bacitracin
agar stored for 4 weeks for isolation of
mutans streptococci from human saliva 
- Bunjird Yapong M.Sc.
- Sissada Tunnukit Ph.D.
- Suwanna Jitpukdeebodintra Ph.D.
Abstract :
Objective The aim of this study was to compare the efficiency of Mitis salivarius bacitracin agar that
were stored for 1,3 and 4 weeks
Materials and methods The paraffin stimulated saliva samples were collected from 20 individuals.
The samples were plated onto MSA and MSB media that were stored at 4°C for 1, 3 and 4 weeks by
spread plate method.
Results The viable count of mutans streptococci on Mitis salivarius bacitracin agar medium that were
stored at 4°C for 1, 3 and 4 weeks were not significantly different. Mutans streptococci grown on these
media displayed typical colony morphology and there was no outgrowth of other species. The viable
count of bacteria was significantly higher in Mitis salivarius agar media without bacitracin than those
with bacitracin media (p < 0.05).
Conclusion Mitis salivarius bacitracin agar medium containing high sucrose (20%) can be stored at
4°C for as long as 4 weeks without losing selectivity for mutans streptococci groups.
(CU Dent J. 2015;38:177-184)
Keywords :
Mitis-salivarius-bacitracin agar; mutans streptococci; Streptococcus mutans