Lecture 1 - Taxonomy, Structure, Physiology

Question 1

Bacteria can be classified as:
1. Frank Pathogens: capable of causing disease in ____ _____ and are always considered a pathogen when _____. Example?
2. Opportunistic Pathogens: capable of causing disease given the ______. Often a ______ and part of the ______ host flora, but is capable
of causing disease in ______ _____ tissues (most
pathogens fall into this group).
3. Non-pathogens: weak or non-pathogenic bacteria can cause disease in hosts with ?

Answer 1

any host, isolated, Yersinia pestis = pathogen that caused the plague.
opportunity, commensal, normal, normally sterile
weakened immune systems.

Question 2

D=N·V/R
D is inversely proportional to?

Answer 2

–D: disease
–N: Number of organisms
–V: Virulence of the organism
–R: Resistance (innate and adaptive
host immunity) of the host

resistance

Question 3

Name the three kingdoms/super-kingdoms in which microbes are characterized?

Answer 3

Bacteria, Eukarya, Archaea

Question 4

Bacterial taxonomy is concerned with:
1. Bacterial _______ schemes are artificial in order to speed up the _______ process, identify bacteria using a limited # of _______.
2. Bacterial nomenclature involves use of a ______ system to assign a _____ and _____, specific conventions for naming.
- Example: Salmonella cholerasuis
3. Bacterial identification is normally based on ______, ________ and _______ “traits”
- other: nucleic acid profile (?). Today, classification is primarily based on?

Answer 4

classification, identification, characteristics, binomial, genus, species, morphological, biochemical, serological, DNA/RNA, DNA protein profiles.

Question 5

Identify the image below

Answer 5

Cocci

Question 6

Identify the image below

Answer 6

Diplococci

Question 7

Identify the image below.

Answer 7

Streptococci

Question 8

Identify the image below.

Answer 8

Staphlococci

Question 9

Identify the image below

Answer 9

Tetrad

Question 10

Identify the image below

Answer 10

Coccobacilli

Question 11

Identify the image below

Answer 11

Club-shaped bacilli

Question 12

Identify the image below

Answer 12

Bacilli with rounded ends

Question 13

Identify the image below

Answer 13

Bacilli with square ends

Question 14

Identify the image below

Answer 14

Fusiform bacilli

Question 15

Identify the image below

Answer 15

Fusiform bacilli

Question 16

Identify the image below

Answer 16

Vibrios

Question 17

Identify the image below

Answer 17

Spirilium

Question 18

Identify the image below

Answer 18

Borrelia

Question 19

Identify the image below

Answer 19

Treponema

Question 20

Identify the image below

Answer 20

Leptospira

Question 21

What is the purpose of the:
1. Flagella
2. Fimbrae
3. Capsule

Answer 21

1. helps bacteria move
2. help bacteria attach
3. outer protective layer

Question 22

Bacterial spores are formed under what circumstances?

Answer 22

Poor nutrition or unacceptable environment

Question 23

The terms gram-positive and gram-negative
refer to the _____ of the bacteria after Gram
staining.
• Gram-positive bacteria have a _____
peptidoglycan cell wall and appear
_____/____.
• Gram-negative bacteria have a ____
peptidoglycan wall, but have a _____-____
outer membrane, and appear ____ after Gram
staining.

Answer 23

color, thick, blue/violet, thin, lipid, rich, red

Question 24

List the steps of a Gram stain procedure

Answer 24

Make a THIN smear from a pure culture on a slide
and heat-fix.
• Cover smear with crystal violet; let stand for 30
sec.-1 min. Rinse.
• Cover smear with Gram’s iodine (mordant); let
stand for same amount of time. Rinse.
• Hold slide at an angle and rinse with alcohol or
alcohol-acetone until blue runs off. Rinse.
• Cover smear with safranin for 30 sec.-1 min.
Rinse, blot dry, and examine under oil immersion
at 100X.

Question 25

Describe the cell wall of a Gram positive bacteria.

Answer 25

Very thick layer, multiple layers, of peptidoglycans on their cell wall
peptido = peptide, AA
glycan = carbohydrate

Question 26

Describe the bacterial cell wall of a gram negative cell.

Answer 26

single layer of peptidoglycans

Question 27

Describe the Peptidoglycan Network,

Answer 27

The amino acids lysine and alanine are linked via a covalent bond. Penicillin binding proteins synthesize peptidoglycans. When the host ingests an antibiotic (Betalactamases which are penicilins, amoxicillin, etc are antibiotics), the antibiotic binds to these proteins, inhibiting the linkage between alanine and lysine.

Question 28

Disruption of Peptidoglycan in Cell Wall
_________ keeps cells intact. When peptidoglycan is attacked, cell is _______ (_____).
Lysozyme or penicillin is _______ under conditions in which it is used (?).

Answer 28

Peptidoglycan, compromised, blebing, bactericidal, hypertonic, hypotonic conditions aka conditions unfavorable to the cell

Question 29

Mycolic acids: acid fast bacteria are a family of ?

Answer 29

very long fatty acid side chains.

Question 30

______ _____ stain (carbofusion) will stain fatty acids

Answer 30

Acid fast

Question 31

Important
Lipopolysaccharide (LPS) – LPS is also known as ______, and is the predominant lipid in the ____ ____ of the outer membrane of the Gram-______ cell. LPS acts as the prototypical endotoxin because it binds the _____/____/_____ receptor complex, which promotes the secretion of ____-_________ cytokines in many cell types, but especially in _______.

________ response induced is what causes the disease.

Answer 31

endotoxin, outer leaflet, negative, CD14/TLR4/MD2, pro-inflammatory, macrophages, Inflammatory

Question 32

Flagella is composed of _______ appendages (2-20 um) composed of flagellin ______; allow for ______; “__” antigens can be detected with specific antibodies.

Answer 32

filamentous, monomers, motility, H

Question 33

Flagella (and pili) may be _______ proteins

Answer 33

glycosylated

Question 34

Glycocalyx – _____ or _____ layer that is composed of ______ or _______; not necessary for _____, but inhibits _______ and _______ uptake; antigenic when on ____ and “_” antigens can be detected with specific ______.

Answer 34

capsule, slime, carbohydrates, glycoproteins, growth, phagocytosis, antibiotic, cell, K, antibodies

Question 35

Capsule-like complex of Francisella tularensis
This CLC is thought to be over-expressed outer membrane vesicles,

Question 36

Pili - _______ appendages (0.5-2.0 um) composed of ___ ______; allow for _______ (____) and specialized ____ ____ allow for transfer of ____ between a donor and a recipient; highly
antigenic and antibodies can be used for ____-_____

Answer 36

filamentous, pilin, monomers, adhesion, fimbriae, sex, pili, DNA, sero-diagnosis

important for attachment, transmitting DNA, transposons, any genetic factors

Question 37

What are the products of bacterial metabolism? What are these products used for?

Answer 37

Acids, bases, gases, ATP
These products are used to build precursors (ATP is de-phosphorylated, phosphorylates glucose, forms intermediates, etc).

Question 38

Bacteria can undergo what processes?

Answer 38

fermentation (anaerobic), respiration/oxidation, or photosynthesis

Question 39

Fermentation process generates _____ and ____.
The oxidation process generates _____.

Answer 39

acids, ATP, NAD

Question 40

ATP Synthesis - on inner membrane
Electrons go through ____ ______ –> generate ____ –> use ____ to ___.

Answer 40

lipid proteins, ATP, ATP, grow

Question 41

Fermenters generate _____, oxidizers generate both ____ and _____ but the ____ are ____

Thermophiles = too ____ for most mammals
psychrophiles = too ___
Mainly dealing with mesophiles

Answer 41

acids, acids, bases, acids, weak
high, low

Question 42

Most bacteria associated with animals grow only in the presence of ____, only _____, either (________), or in ____ and are able to ferment or oxidize _____
– e.g. E. coli, Pasteurella, Staphylococcus –> These bacteria are _______ ______ (fermenters or acid formers), but normally grow better in ___
• Some bacteria are aerobes and only _______ sugars (some acids made but are too ____ to detect)
– e.g. Pseudomonas, Aeromonas, Acinetobacter
• Some bacteria are aerobes, but do not utilize ____ at all
– e.g. Bordetella, Moraxella –> These bacteria utilize _____, ____, or other ______ ______
from ______ _____ or other compounds other than sugars.

Answer 42

air, anaerobically, facultatively, CO2, sugars, facultative anaerobes, air, oxidize, weak, sugars, nitrogen, sulfur, electron acceptors, amino acids

Question 43

Some bacteria only grow well in the presence of ____ quantities of ____ (3%)
(_______)
– e.g. Campylobacter jejuni
• Some bacteria only grow in air with additional ______ ______ (______)
– e.g. Haemophilus
• Some bacteria only grow in the absence of ____ and only _______ sugars (anaerobic)
– e.g. Bacteroides

Answer 43

low, oxygen, microaerophilic, carbon dioxide, capnophilic, air, ferment

Question 44

What are the types of Bacteriological Culture Medium?
What are types of media used for isolation and identification?

Answer 44

Two basic types:
• Defined/ simple (e.g. minimal salts)
• Enriched/complex (e.g. nutrient broth)
Examples used for isolation and identification
1. Differential media (e.g. MacConkey agar)
2. Selective media (e.g. Selenite broth)
3. Enriched media (e.g. Blood agar)
4. Transport media (e.g. Stuart’s media)

Question 45

Summary of Bacterial Physiology
1. Define Metabolism.
2. ATP is synonymous with?
3. Most bacteria are?
4. The by-products of metabolism can be used for?
5. What factors can influence bacterial growth?

Answer 45

1. Metabolism is the net result of biochemical activities associated with catabolic and anabolic pathways - leading to growth.
2. ATP is synonymous with energy generation - can occur by photosynthesis, respiration or fermentation.
3. Most bacteria are chemoheterotrophs.
4. • The characterization of by-products associated with metabolism can be used to identify bacteria e.g. “metabolic footprint” (API 20E).
5. The incubation conditions of temperature, gas and pH can significantly influence the rate at which bacteria grow. • Culture media can be designed to facilitate growth as well as transport and identification of bacteria.