The document discusses normal flora, which are the microorganisms that normally inhabit various areas of the human body. It defines normal flora as organisms that permanently reside in certain anatomical locations. There are two classes: resident flora that are relatively fixed, and transient flora that inhabit areas for shorter periods. Resident flora play an important role in health by preventing pathogenic colonization and aiding nutrient absorption. While normally harmless, normal flora could potentially cause disease if introduced to foreign body sites or if the host is immunocompromised. The document then lists and describes some of the normal flora found in different body areas like the skin, gut, and mouth.

1. Normal flora
Almugadam B Saad
Lecturer of medical microbiology
Faculty of medical laboratory sciences
University of El Imam El Mahadi
Full name
Babiker Saad Almugadam Yousif
University of El Imam El Mahadi
Kosti-Sudan
MSc University of Khartoum
BSc University of El Imam El Mahadi

2. Normal flora
By the end of this session,
you should know
Learning
objectives
-Definition of normal flora term
-Role of resident flora
- Harmful aspect
-Normal flora of different
anatomical part

3. -The term describe the organism (bacteria or fungi) which
permanent resident on certain anatomic location in the body.
- Classes of normal flora of the skin and mucus membrane (MM) :
1- Resident flora : relatively fixed organism , found in certain
location of the body at a given age
2- Transient flora : Nonpathogenic or potentially pathogenic
organism that inhibit skin or MM for hours or days or weeks.
- Role of resident flora :
play role in maintaining health and normal function.
1- Prevent the colonization of skin and MM with pathogen
through colonization resistant (saturation of binding site ,
consumption of nutrient and bacteriocidal product)
2- Intestine flora synthesize vitamin K and aid absorption of
nutrients

4. - Harmful aspect :
May produce disease if introduce into foreign location in large
numbers , or if predisposing factor are present.
- Normal flora of different anatomical part :
1- Skin :
Predominant flora : S.epideridis 10 3-4
Others : ?
2- Conjunctiva :
Predominant flora : Predominant flora : Diptheroids , S.epideridis
, Nonhaemolytic streptococci , Nessieria and Moraxella species.
Others : ?
3- Vagina :
Predominant flora : Lactobacilli
Others : ?

5. 4- GIT :
Stomach : Only very few organism
Small intestine :
Colon :
20% of stool bacteria (10 11 organism/g) , ↑ than 90% of faecal
flora are anaerobe(most Prdominant B.fragilis ).
Predominant flora : B.fragilis , E.coli (Prdominant facultativePredominant flora : B.fragilis , E.coli (Prdominant facultative
anaerobe ).
Others : ?
5- Urethra :
Sterile , only anterior part of both sex contain small number skin
flora and perineum.
Predominant flora : Predominant flora : Diptheroids , S.epideridis

6. , Nonhaemolytic streptococci , Nessieria and Moraxella species.
Others : ?
6- Mouth and URT :
Throat and Mouth :
Predominant flora : viridans streptococci
Dental plaque : S.mutans 10 10/g
Others : ?