Exam 2-bacteriology Flashcards
(90 cards)
1
Q
Gram + bacteria
A
Thick peptidoglycan
Contains Lipoteichoic acid
2
Q
Gram + staining
A
- Use crystal violet
- If a bacteria is gram positive the bacteria will stain purple.
- the crystal violet and grams iodine complexes cannot escape a thick peptidoglycan layer
3
Q
Gram - bacteria
A
- Thin layer of peptidoglycan
- contains LPS (lipopolysaccharides)
- only ones to have outer membrane which contains LPS
4
Q
Gram - Staining
A
- Gram - bacteria will stain pink
- the bacteria pick up the Safrain due to inn peptidoglycan
- Allows for passage of large crystals
5
Q
Mycobacterium
A
Contains mycolic acid and LAM (Lipoarabinomaman)
6
Q
Mycobacteria staining
A
Acid fast + = pink
Acid fast - = blue (lack of mycolic acid)
-will only work if mycobacterium present
7
Q
E.coli K88 fimbria
A
Neonatal pigs
8
Q
E.coli K99 fimbria
A
Neonatal calfs
9
Q
Pili/fimbrae
A
- Used for adherence
- on bacteria’s surface
- small thread-like
10
Q
Capsule
A
- Outer covering, helps to Nevada phagocytes
- polysaccharide of the outside of the cell wall
11
Q
What is the Capsule used for?
A
- sticking cells together
- food reserve
- protection against dedication and chemicals
- helps bacteria to evade apoptosis
12
Q
Endospores
A
- Survival mechanism for some G+ bacteria
- highly resistant dormant form of bacteria
- produced when bacteria are exposed to adverse conditions or essential nutrients are depleted
13
Q
Oxygen required
A
Aerobic
Microaerophilic
Capnophilic
14
Q
Oxygen Not required or utilized for growth
A
Obligate anaerobe
Aerotolerant anaerobe
15
Q
Oxygen not required and not utilized for growth
A
Facultative anaerobe
16
Q
How do bacteria cause disease?
A
Pathogenesis
17
Q
Triangle of Tragedy-Pathogen
A
Type Genotype Survival Virulence Route Tropism Dose Resistance Vector
18
Q
Triangle of Tragedy- Host
A
Breed Age Sex Genotype Immunity Physiology Damage
19
Q
Triangle of Tragedy-Enviroment
A
Housing Space Ventilation hygiene Nutrition Disease control Survival
20
Q
Microorganism that has the potential to cause disease
A
Pathogen
21
Q
The invasion and multiplication of pathogenic microbes in an individual or population
A
Infection
22
Q
When the infection causes damage to the individuals vital functions or systems
A
Disease
23
Q
Site at which microbes enter our bodies
A
Port of entry
24
Q
What are the 4 sites that microbes can enter the body?
A
1) Skin
2) Mucous membranes of respiratory tract
3) Gastrointestinal tract
4) Urogenital tract
25
Proteins produced by bacteria and released to outside and they exert action of specific target cells, release when living
Exotoxins
26
Examples of Exotoxins
Neurotoxins
Leukotoxins
Entertoxins
27
Heat stable, only released when dead, they can induce inflammation by stimulating the immune system
Endotoxins
28
Superantigens
- Produced by pathogenic microbes
- (including viruses, mycoplasma, and bacteria)
- Bind to MHC class II molecule --> which binds to T-helper cells (massive cytokines release)
- nausea, vomiting, fever (shock)
29
Examples of superantigens
Staphylococcus
| Streptococcus entertoxins
30
Smaller circular DNA present in bacteria
Plasmids
31
Virus particles which attack bacteria
Bacteriophages
32
The process by which one bacterium transfers genetic material to another through direct contact
Conjugation
33
The genetic alteration of a cell resulting from the direct uptake and incorporation of exogenous genetic material from its surrounding and taken up through the cell membranes (add DNA fragment into DNA)
Transformation
34
The process by which DNA is transferred from one bacterium to another by a virus
Transduction
35
Mechanisms by which cause disease
Pathogenesis
36
Degree of pathogenicity includes severity
Virulence
37
Properties or traits found in isolates that cause disease but which are not found in isolates of the same species that lack the ability to cause disease
Virulence factors
38
What predisposes an animal to infectious disease
Predisposition
39
Sequence of events in bacterial or fungal pathogenesis
1) Entry into the host
2) Evade host defense
3) Colonize the host system
4) Multiply
5) Exert damage in the host
6) Transmit to other hosts - infectious
40
How bacterial pathogens cause disease?
1) Depleting the host's nutrients by using them
2) Direct damage to the host cell (toxins)
3) As a result of immune response to the microbe
4) Combination of all
41
Consequences of Pathogen-host Interaction
-No colonization/ colonization
-Inapparent subclinical/ chronic infection
-Infection, disease followed by recovery
-infection, disease, death, or disability
-Infection, disease, followed by persistence
(Often leading to transmission or carrier stage)
42
Diagnosis of Bacterial Infections
1) Infection of the agent
| 2) Identification of the host immune response
43
Ways to identify the agent in the diagnosis of bacterial infections
- direct detection (microscopic, simple/differential staining, fluorescent antibody staining)
- Isolation and ID
- direct detection of antigens, toxins (ELISA)
- PCR
44
Ways to identify the host immune response of bacterial infections
1) humoral immune system detect antibodies to an infectious agent (Brucella infection)
2) cell-mediated immune response (TB)
45
Type of media selective to Salmonella
Hektoen Enteric Agar
46
Media that is selective for G- bacteria
MacConkey
47
A media selective for G+ bacteria
Phenylethyl alcohol agar
48
Aerobic
Bacteria that needs oxygen
49
Microaerophilic
-needs low amount of oxygen
50
Capnophilic
Needs CO2 to grow
51
oxygen not required but can be utilized for growth
Facultative anaerobe
52
Antigen Detection
-Use antibody reagents. To detect antigens in serum, feces, urine, tissue
53
Examples of antigen detection
Enzyme immunoassay
Agglutination
Fluorescent antibody staining
54
Chemical Detection
- Analysis of total cell fatty acids/ proteins
| - limited use on clinical specimens
55
Examples of Chemical detection
HPLC
GLC
MALDI-MS
56
Biological detection
-Adapted from clotting mechanism of horseshoe crab
57
Examples of Biological detection
Linulus amoebocyte assay test for LPS
58
Sterilization Methods
- Moist heat
- Dry heat
- Incineration
- Alcohol flame
59
Methods used to limit microbial growth
- Fridge
- Boiling
- Pasteurization
- Acidification
60
Drugs that destroy microbes, prevent their multiplication/growth/prevention their pathogenic effect
Antimicrobials
61
A low molecular substances produced by a microorganism that at a low concentration inhibits or kills other micro organisms
Antibiotic
62
Any substance of natural, semi-synthetic, synthetic orgin that kills or inhibits the growth of micro organisms but causes little or no damage to the host
Antimicrobial
63
** all antibiotics are antimicrobials, but not all antimicrobials are antibiotics
**
64
Natural Antimicrobials
-produced by bacteria or fungus
65
Examples of Natural Antimicrobials
- Streptomycin
- Penicillin
- Tetracycline
66
Semi-synthetic Antimicrobials
-chemically altered natural compound
67
Examples of Semi-synthetic antimicrobials
- Ampicillin
| - Amikacin
68
Synthetic Antimicrobials
0chemically designed in the lab
69
Examples of synthetic antimicrobials
- Sulfonamide
- Enrofloxacin
- Macbofloxacin
70
4 Classification of antimicrobial agents
1) chemical structure
2) mode of action
3) type of antimicrobial activity
4) Spectrum of antimicrobial activity
71
Prevents degradation of penicillin by B-lactamose
Clavulanic acid
72
B-lactate antibiotics
Penicillin, Ampicillin, Cephalosporins
73
An enzyme present in bacteria which can cleave B-lactate ring and inactivate penicillin + contribute to resistance
B-lactamase
74
Last drugs of choice for some gram+ bacteria
Vancomycin and daptomycin
75
Examples of Quinolones
- Nalidixic acid
- Ciprofloxacin
- Enrofloxacin
76
Metronidazole
-makes breaks in the DNA
77
Inhibits 30s subunit
- Aminoglycosides (bacterial ribosome)
| - Tetracyclines (reg ribosomes)
78
Examples of Aminoglycosides
- Gentamicin
| - Amikacin
79
Examples of Tetracyclines
- Oxytetracycline
| - Chlortetracycline
80
Inhibits 50s subunit
- Macrolides
- Chloramphenicol
- Lincosamides
81
Examples of Macrolides
- Erythromycin
| - Azithromycin
82
Inhibits RNA polymerase (transcription)
Rifampin
83
Inhibits tRNA synthetase (translation)
Mupirocin
84
Folic acid Synthesis Inhibitors
- Sulfonamides
| - Trimethoprim
85
Broad Spectrum antibacterials
Active against both Gram + and Gram - organisms
86
Examples of Broad Spectrum antibacterials
- Tetracyclines
- Chloramphenicol
- Fluoroquinolones
- Cephalosporins
87
Narrow spectrum antibacterials
-have limited activity and are primarily only useful against particular specie of microorganisms (G+ and G-)
88
Examples of Narrow Spectrum antibacterials
- Isoniazid
| - Polymyxins
89
Bactericides Agents
-Kills bacteria and reduces the total # of viable organisms
90
Bacteriostatic agents
-Arrest the growth and replication of bacteria, thus allowing the host immune system to complete pathogen elimination
