Core Ii, Lecture 6, Bacteriology

Front 1

To a bacteria, the human body is...

Back 1

a collection of environmental niches that provide warmth, moisture and food necessary for growth.

Front 2

What is normal flora?

Back 2

Normal flora: The human body is colonized with numerous microbes (normal flora), many of which serve important functions for their hosts. Normal flora bacteria aid in the digestion of food, produce vitamins (e.g., vitamin K), and can protect the host from colonization with pathogenic microbes. Normal flora bacteria cause disease if they enter normally sterile sites of the body.

Front 3

What is the co-evolution of bacteria and humans?

Back 3

Co-evolution: how bacteria continues to change to evade our immune system, but we also change in order to fight it.

Front 4

What are the three types of relationships between bacteria and host?

Back 4

1. Commensal (not harmful)
2. Symbiotic (mutually beneficial)
3. Pathogenic/Parasitic: bacteria lives in the host and causes tremendous damage to the host

Front 5

Pathogenic Bacteria:
vs
Opportunistic Bacteria

Back 5

- bacteria that always cause diseases
vs-
normally they are part of the normal flora; but when there is an opportunity host immune system is down), they can cause disease.
So if you have a healthy immune system, opportunistic pathogens cant hurt you.

Front 6

Host defense against infections:
1st line of defense:?
2nd line of defense:?

Back 6

1st: Skin (barrier), mucosal membranes: mucus, ciliated epithelium and secretion containing antibacterials

2nd: innate immunity and acquired immunity

Front 7

What are the five steps to establishment of an infection by an invader?

Back 7

1 Entry/Attachment
2 Replication
3 Evasion of Host Defense
4 Spread (local/systemic)
5 Exit

Front 8

What are the PORTS of entry into a human host:

Back 8

1. Mouth (GI and Respiratory)
2. Urogenital Track
3. Skin (injury, vector)

Front 9

Why does natural bladder function sometimes not get rid of bacteria like E Coli?

Back 9

Escherichia coli and other bacteria have adhesins that bind to specific receptors on the tissue surface, which keep them from being washed away.

Front 10

Shigella and Salmonella both cause disease to:?
How (mechanism)?
How are they different?

Back 10

1. GI tract.
2. Mechanism: Enteric bacteria Shigella, Salmonella, and Yersinia organisms use fimbriae to bind to M (microfold) cells of the colon, and then inject proteins into the M cell that stimulate the cell membrane to surround and take in the bacteria.
3. Shigella can then spread to adjacent cells, whereas Salmonella can pass through to the other side and initiate systemic infection.

Front 11

Urine Flushing action only works when:

Back 11

before bacteria creates its adhesion

Front 12

Host defense mechanisms against entry:
1. Respiratory: ?
2. Intact Skin
3. GI tract
4. Urinary tract

Back 12

1. Ciliated Epithelium of lung actively remove invaders.
2 Gland secretions and Normal Flora
3 Peristalic movements, and NOrmal Flora
4. Flushing action of urine to remove invaders

Front 13

What happens when you have too much antibiotics?

Back 13

The antibiotics may kill the normal flora in the GI tract. This changes the environment and may allow opportunistic pathogens to grow where normal flora used to live.

Front 14

Intracellular vs Extracellular of bacterial invasion:

Back 14

1. Intracellular: bacteria can enter cells by endocytosis through epithelium , OR it can be phagocytosed with macrophages
2. Extracellular Bacteria grow in the extracellular spaces of tissue

Front 15

Unlike most bacteria, control of the intracellular bacterial infections requires:

Back 15

TH1 T-helper cell immune responses, which activate macrophages to kill or create a wall around the infected cell (as for Mycobacterium tuberculosis).

Front 16

Bacteria that grow intracellularly include

Back 16

mycobacteria, francisellae, brucellae, chlamydiae, and rickettsiae

Front 17

M. tuberculosis is able to survive in a host by promoting the development of a ??
What is a ??

Back 17

GRanuloma
- A compartment formed within which viable bacteria may reside for the life of the infected person. The bacteria may resume growth if there is a decline in the immune status of the person

Front 18

Neisseria gonorrhoeae can evade our immune system by:

Back 18

vary the structure of surface antigens to evade antibody responses and also produces a protease that degrades immunoglobulin A (IgA).

Front 19

Rickettsiae Spread out through

The live in:

Back 19

Insects. Lice, mite, flees
-humans and other animals

Front 20

Phagocytes include:

Back 20

Neutrophils and macrophages!

Front 21

the S. pyogenes capsule is special because:

Back 21

mimics human connective tissue, thereby masking the bacteria and keeping them from being recognized by the immune system