Riverdale- Agar Plates

The majority of the blobs you see on the plates are gram positive bacteria. We tested this by using a gram stain

chemical.

Some of the plates have larger, cloudy looking blobs, most likely to be yeast. Whilst a few have larger blobs with

filaments protruding from them, which could be a fungi like bacteria called Nordica, from soil but found on skin and

even in salvia.

Remember it is perfectly normal to have these living on or in you and you body keeps them under-control with the

immune system.

Skin bacteria• Skin flora are usually non-pathogenic, and either commensals (are not

harmful to their host) or mutualistic (offer a benefit).

• Most come from four phyla: Actinobacteria (51.8%), Firmicutes (24.4%), Proteobacteria (16.5%), and Bacteroidetes (6.3%).

• Actinobacteria (including Nordica) and Firmicutes are both gram positive bacteria.

Oral bacteria• Adult mouths may contain 500 to 1,000 different types of bacteria as part of the

human flora and oral microbiology, but about 100 to 200 species may live in them at any given time.

• Those who care for their teeth and have a relatively clean mouth have 1,000 to 100,000 bacteria living on each tooth surface.

• Those that do not have a clean mouth have between 100 million and 1 billion bacteria on each tooth.

• Streptococci (gram positive) make up a large part of oral bacteria.

• Some bacteria are needed to control the growth of fungus.