Bacterial Normal Flora Introduction

Bacterial Normal Flora Introduction • Normal bacteria flora describes bacteria and fungi that are permanent residents of certain body sites without causing a disease. • Viruses and parasites are never considered members of the normal flora • Human first becomes colonized by normal flora at birth • They vary in number and kind from one site to another • The internal organs and the blood are usually sterile and presence of bacteria on these sites is an indication of disease. • Produce endogenous diseases- Mostly opportunistic infections Two categories: 1. Transient Flora Inhabit the skin and mucous membrane for a short period then disappear Are derived from the environment Cannot produce disease unless when in large numbers 2.Resident Flora Are fixed and found in certain parts of the host Re-establish themselves if they are disturbed  Distribution of normal flora is influenced by; Temperature Environment pH of the secretions Availability of oxygen and moisture Diet Anatomic parts; e.g. vaginal flora is more susceptible to infection  All these may be reduced by antimicrobial agents and hormonal activity Gender and hormonal activity General health of the person Age of the individual