Contribution towards developing a new semi-selective medium for Streptococcus anginosus group

Area of Science:

• Microbiology
• Clinical Diagnostics
• Bacteriology

Background:

• The Streptococcus anginosus group (SAG) are opportunistic pathogens.
• Accurate isolation of SAG from clinical samples is crucial for diagnosis.
• Existing media may lack specificity for SAG isolation.

Purpose of the Study:

• To develop and evaluate a novel selective medium for the isolation of Streptococcus anginosus group (SAG) strains.
• To enhance the selective recovery of SAG from various clinical specimens.

Main Methods:

• Development of Mitis-Salivarius--sulphamethazine--aztreonam agar (MSSAA) by supplementing Mitis-Salivarius agar (MSA) with sulphamethazine and aztreonam.
• Testing the growth of SAG type strains and clinical isolates on MSSAA.
• Comparing SAG recovery and non-SAG strain inhibition on MSSAA versus MSA using saliva and pus samples.

Main Results:

• MSSAA demonstrated comparable SAG recovery rates to the standard MSA medium.
• Non-SAG strains, including other oral streptococci, showed inhibited growth on MSSAA, with enterococci as a minor exception.
• The novel MSSAA medium proved effective in selectively isolating SAG from clinical specimens.

Conclusions:

• Mitis-Salivarius--sulphamethazine--aztreonam agar (MSSAA) is a suitable and selective medium for isolating Streptococcus anginosus group (SAG) strains.
• MSSAA offers an improved method for the targeted recovery of SAG in clinical microbiology settings.
• This development aids in the accurate identification and study of SAG-related infections.