What is one of the best defence's against bacteria infection?

Answer 1

The skin is the largest organ of the body and covers the largest surface area. The upper layers, epidermis, are mostly made up of keratin. This protein is hard especially in the Stratum Corneum and prevents bacterial infections providing it is intact.

There is also a layer of sebum and sweat over the epidermis which is called the Acid Mantle. This Acid Mantle prevents bacteria from developing on the skin due to its acidity. Bacteria prefer to grow in a neutral pH.