Microbiota and Normal Flora Overview

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Questions and Answers

What vitamin is synthesized by normal flora in the intestine?

Vitamin D

Vitamin A

Vitamin K (correct)

Vitamin C

Which benefit is associated with normal flora?

Promotes inflammation

Increases susceptibility to infections

Produces anti-bacterial chemicals (correct)

Inhibits digestion

Which of the following statements about normal flora is FALSE?

They protect against harmful pathogens.

They cause systemic infections in healthy individuals. (correct)

They can enhance the immune response.

They help synthesize vitamins.

What is a potential risk of an imbalance in normal flora?

Proliferation of harmful pathogens Signup and view all the answers

Which of the following is NOT an advantage of normal flora?

Inhibition of beneficial bacteria Signup and view all the answers

Which organism is considered a resident flora of the skin?

Staphylococcus epidermis Signup and view all the answers

What can happen when a needle pierces the skin?

It can cause systemic infections. Signup and view all the answers

Which of the following is a yeast that can be found in the normal flora of the skin?

Candida albicans Signup and view all the answers

Which of the following statements about normal flora is accurate?

Resident flora can contribute to systemic infections in certain conditions. Signup and view all the answers

What risk increases when the skin is compromised, such as through a needle puncture?

Increased risk of introducing microorganisms into the bloodstream. Signup and view all the answers

What type of bacteria are predominantly found in the large intestine?

Bacteriodes species Signup and view all the answers

What is one factor that can lead to microbiota-related diseases?

Weakened immune system Signup and view all the answers

Which part of the small intestine has a lesser number of microbiota?

Duodenum Signup and view all the answers

What can result in changes to the local environment affecting microbiota?

Usage of antibiotics Signup and view all the answers

Which of the following is NOT a condition that can allow microbiota to cause disease?

Physical barriers Signup and view all the answers

What happens to streptococci after a tooth extraction or oral surgery?

They enter into the blood. Signup and view all the answers

What is a common consequence of oral surgery regarding bacterial activity?

Migration of oral bacteria into the bloodstream. Signup and view all the answers

Which statement correctly describes the behavior of oral bacteria following tooth extraction?

Oral bacteria can enter the bloodstream. Signup and view all the answers

After which procedure is it common for streptococci to enter the bloodstream?

Tooth extraction or oral surgery. Signup and view all the answers

Which bacteria are known to potentially enter the blood following an oral surgery?

Streptococci. Signup and view all the answers

What harmful bacteria can be found in Formula Milk that may cause disease in infants?

Salmonella Signup and view all the answers

How does a person's age affect their normal flora?

It can vary depending on a person's age. Signup and view all the answers

Which of the following statements about Formula Milk is true?

It can contain bacteria that are harmful to infants. Signup and view all the answers

What is a potential risk associated with feeding infants Formula Milk?

It may introduce harmful bacteria. Signup and view all the answers

Which bacteria are particularly noted for being transmitted through Formula Milk?

Salmonella and Cronobacter Signup and view all the answers

What is the primary benefit of regular handwashing?

It helps prevent the spread of harmful bacteria. Signup and view all the answers

How does maintaining a healthy balance of normal flora benefit an individual?

It assists in digestion and immunity. Signup and view all the answers

What is a consequence of neglecting hand hygiene?

Increased susceptibility to infections. Signup and view all the answers

Which practice is most effective for maintaining normal flora balance?

Regular handwashing with soap. Signup and view all the answers

Why is the knowledge of hygiene practices crucial in medical microbiology?

It plays a role in minimizing infection spread. Signup and view all the answers

Study Notes

Microbiota (Normal Flora)

Normal flora is the population of microorganisms inhabiting the skin and mucous membranes of healthy people
Also known as microbiota or microbiome or microflora
Total population of normal flora in humans is 10¹⁴, while the total number of cells is 10¹³
Normal flora can sometimes cause disease when they leave their original site

Advantages of Normal Flora

Synthesize vitamins like Vitamin K and B12 in the intestine
Produce antibacterial chemicals to suppress pathogens

Disadvantages of Normal Flora

Normal flora can become pathogenic when the immune system is lowered
Abnormal multiplication of normal flora leads to diseases

Types of Normal Microbiota

Resident Flora

Always present
Found in specific areas at a given age
Re-establishes itself
Causes diseases if disturbed
Fixed microorganism

Transient Flora

Remains for hours, days, or weeks
Comes from the environment
Non-pathogenic microorganisms
Temporary

Location Sites of Normal Flora

Skin
Eyes (conjunctiva)
Nose (respiratory tract)
Mouth
Ear (external ear)
Urogenital tract
Gastrointestinal tract

Sterile Sites in the Human Body

Blood
Cerebrospinal fluid (CSF)
Body fluid (peritoneal, pleural)
Internal organs and tissues

Normal Flora of Skin

Resident flora: Staphylococcus epidermis
Candida albicans can reach the bloodstream and cause systemic infections if the skin is pierced

Normal Flora of Oral Cavity

Sterile at birth but colonized after 4-12 hours by Viridans streptococci
Streptococcus sanguis (dental plaque)
Streptococcus mutans secrete a biofilm and produce dental caries

Normal Flora of Respiratory Tract

Upper respiratory tract (nose-oropharynx)
Lower respiratory tract is sterile (trachea-bronchi-pulmonary tissue)

Normal Flora of Genitourinary Tract (GU)

Gut is sterile except the vagina and the distal 1 cm part of the urethra
Female genital tract is more heavily colonized than the male genital tract
Due to:
- Shorter female urethra
- Shorter distance between the opening of the urethra and anus
- Vagina is heavily colonized

Normal Flora of Gastrointestinal Tract (GI)

Predominant site, colonized with bacteria
Stomach contains only a few bacteria due to acidic pH
Small intestine: a few in the upper part, while the lower part is more abundant
Large intestine: 99% bacteria are Bacteroides species

Conditions Where Microbiota Cause Disease

Weakened immune system
Changes in the local environment
Disruption of microbiota
Presence of medical devices

Role of Microbiota

Defense against pathogens
Stimulate the immune system
Nutrient synthesis
Maintaining pH

factors affecting Normal Flora

Mode of delivery
Infant feeding
Age
Antibiotics
Medications
Surgery
Hygiene practices
pH and oxygen and temperature

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Description

This quiz explores the concept of normal flora, also known as microbiota. It covers their advantages, disadvantages, and the different types of normal microbiota present in the human body. Understanding normal flora is essential for recognizing their role in health and disease.