General Bacteriology/Pathogenicity Flashcards
(172 cards)
1
Q
Significance of Microbiology
A
- Diagnosis & Treatment
- Public Health
- Vaccines & Therapeutics
- Human Microbiome
- Biosecurity (bioterrorism)
2
Q
Subfields of Microbiology
A
- Bacteriology
- Virology
- Mycology (fungi)
- Parasitology (protozoa/helminths)
- Prions (infectious agents)
3
Q
Antoine van Leewenhoek
A
Dutch Scientist - 1670
- Developed Simple Microscope & observed microbes describing them as Animalcules (small animals)
4
Q
Edward Jenner
A
English Physician - 1769
- Vaccination using cowpox to prevent Smallpox
- Infected young boy with cowpox from milkmaid & then tried smallpox & he was immune (unethical)
5
Q
Ignaz Semmelweis
A
Hungarian - 1847
- Handwashing with Chlorine in maternity wards to prevent puerperal fever (postpartum sepsis)
- Identified that medical personnel spread it
6
Q
Paul Ehrlich + Sahachiro Hata
A
German/Japanese - 1910
- Discovered Salvarsan: effective treatment for Syphilis
7
Q
Alexander Fleming
A
Scottish microbiologist - 1928
- Discovered Penicillin, the first Antibiotic, released in 1940 due to production issues
- Warned against antibiotic resistance
8
Q
Comparison points of Pro/Eukaryotic cells
A
- Examples of Organisms
- DNA
- Organelles
- Ribosomes
- Reproduction
- Respiration
- Membrane (sterol)
- Cell wall (peptidoglycan/chitin-cellulose)
9
Q
Taxonomy
A
System to classify Bacteria into groups based on similarities/differences
- K-P-C-O-F-G-S
- Genus & Species used
10
Q
2 Major Bacterial Domains
A
- Eubacteria (true bacteria, common)
- Archaebacteria (usually extremophiles)
11
Q
Bacteria Shapes
A
- Cocci (spherical)
- Bacilli (rods)
- Spirilla (spiral)
12
Q
Bacteria can be classified based on
A
- Shape
- Gram-Staining
- Biochem. Tests (sugars)
- Genetic tests
13
Q
Which is a obligate component Nucleoid or Plasmid?
A
Nucleoid
14
Q
Obligate Bacterial Structures
A
- Nucleoid
- Ribosomes
- Cytoplasm
- Plasma Membrane
- Cell wall (some exceptions)
15
Q
Facultative Bacterial Structures
A
- Flagellum
- Fimbriae / Pilli
- Capsule (usually polysac.)
- Spores
16
Q
Types of Pilli
A
- Sex pilli
- Common pilli
- Adhesive pilli
17
Q
Antigens associated with Bacteria
A
- Flagellum: H-antigen
- Capsule: K-antigen
18
Q
What is peptidoglycan made up of?
A
NAG & NAM (disaccharides)
Linked by B-1,4-Glycosidic bonds
19
Q
Bacteria Cell wall structure
A
- NAM has a short peptide chain attached (2-5 aa long)
- Cross linking bw peptide chains forming mesh-like structure of cell wall
20
Q
What actively cross links Bacterial cell wall
A
Transpeptidases
- PBP: penicillin BP is an important TP
- B-lactams can bind PBPs
- Bacteria can modify their PBPs to make them resistant
21
Q
Gram Positive cell wall
A
- 20-80 nm
- Thicker peptidoglycan layer
- Teichoic Acids & Lipoteichoic acids covalently linked to peptidoglycans which acts like an antigen providing resistance against Lysozyme
22
Q
Gram Negative cell wall
A
- 10-15 nm
- Much thinner peptidoglycan layer
- Inner & outer double membranes
- LPS/Endotoxin on outer membrane
23
Q
Lipopolysaccharide LPS / Endotoxin
A
- Made of O-Antigen, Core, Lipid A
- O-Antigen provokes immune response
- LPS released upon lysis of Gram neg. bacteria
24
Q
Bacterial Energy sources
A
- Phototrophy
- Chemotrophy (organo/litho-)
25
Bacteria Carbon sources
- Autotrophs: Can synth organic compounds from inorganic sources like CO2
- Heterotrophs: Require organic carbon sources (sugars, a.a)
26
What Carbon source do Human pathogens use
Heterotrophs
- Use nutrients from Host/Us as energy source
- Use their own enzymes to breakdown nutrients
27
Obligate Aerobic
Can only grow in O2 presence (die without it)
28
Obligate Anaerobes
O2 kills them
29
Facultative Anaerobes
O2 needed, but can ferment too
30
Aerotolerant Anaerobes
Fermentation, but can tolerate O2
31
Microaerophils
Needs decreased O2, Increased CO2
32
Capnophiles
Needs increased CO2
33
Bacterial Genetics
Study of how bacteria inherit, exchange, & express genetic info
34
Reversion
A genetic change that restores the original Phenotype, reversing the effect of a previous mutation
35
Types of Reversion
- True reversion: Exact original sequence restored
- Equivalent reversion: A different sequence but same a.a returned restoring the function
36
When can reversion be dangerous?
Attenuated pathogen vaccines where the mutated gene can turn back on to the original wild-type gene
37
Modes of Gene transfer
- Vertical: transfer of genetic info from parent to offspring
- Horizontal: transfer of genetic info bw bacteria that are not parent & offspring
38
Horizontal Gene Transfer
- Transformation: Acquisition of Gene from environment
- Conjugation: Direct DNA transfer through Sex pilus (like plasmids)
- Transduction: Transfer via bacteriophages
- Transposition: Movement of transposons within & bw DNA molecules
39
Sterilization Def
Killing or removal or irreversible inactivation of all micro-organisms leading to a germ-free/sterile condition
40
Heat Sterilization
- Burning/Incineration
- Hot air sterilizer (long time)
- Autoclave (steam)
41
Hot air sterilizer times
- 140°C for 3hr
- 160°C for 2hr
- 180°C for 1hr
42
Autoclave times
- +1atm, 121°C, 20-30 minutes
- +2atm, 134°C, 10 minutes
43
Irradiation sterilization
- UV-light
- Gamma irradiation
44
Chemical Sterilization
- Gas (toxic, e.g. formaldehyde)
- Plasma (H2O2)
45
Mechanical sterilization
Filtration
- Only really works for Bacteria & fungi, viruses can still pass
- HEPA filter is an example
- Commonly have 0.22 μm & 0.45 μm pores
46
Sterilization of Prions
1) Pretreat with strong base 2N NaOH for 1 hour (or 1N for 2 hours)
2) Autoclave at 134°C +2 atm for 1 hour
3) Repeat steps 1 & 2
- Or we can just combust at 1000°C
47
Disinfection
Decreasing the number of microbes, not complete sterilization
48
Heat Disinfection
- Boiling (100°C, 20-30min)
- Pasteurization (65°C 30min, 85°C 5min)
- UHT (135°C, 3-5s)
- Tyndallisation (85°C 30min, 37°C overnight & repeat)
49
Disinfectant vs Antiseptic
- Disinfectant: Chemical agent used for non-living surfaces
- Antiseptic: Chemical agent used on living surfaces (skin, mucosa)
50
Chemical Disinfection
- Detergents
- Alcohols
- Phenols
- Acids/Bases
- Heavy metal salts
- Oxidizing agents (Cl, I, H2O2)
- Alkylating Agents
51
Phenol Coefficient Test
Determine relative effectiveness of a disinfectant compared to Phenol
1) Prep series of dilution of disinfectant & phenol as reference
2) Use standard bacterial culture adding fixed amount to each dilution
3) Incubate & inoculate samples on Agar plates
(1 used as effectivity)
52
Selective Toxicity
Antimicrobial drug is harmful to the pathogen but not to the Host
(not 100% possible)
53
Chemotherapeutic Index
DTM / DCM
Dosis Tolerata Maxima / Dosis Curativa Minima
(the higher the index, the safer the drug)
- Penicillins & Macrolides = High
- Aminoglycosides & Vancomycin = Low
54
Types of Antibiotic Therapy
- Targeted therapy (after AST)
- Empirical therapy (broad-spec)
- Prophylactic therapy (prevention)
55
What is Aim of Antibiotic therapy
If pathogen is unknown we start with Broad-spec but we aim to Narrow it down as much as possible based on tests
56
Do we prefer combining drugs?
Not really, Monotherapy is Preferred
57
Reasons for combining drugs
- Broaden spectrum in Empirical
- Treatment of very resistant pathogens
- Synergism bw antibiotics
58
Combination Example Tuberculosis
1st line RIPE:
- Rifampicin
- Isoniazid
- Pyrazinamide
- Ethambutol
59
Combination Example H.Pylori
Tripple combo
- 2 Antibiotics (Amoxicillin + Clarithromycin)
- PPI
60
Combination Example Unknown Sepsis
- Vancomycin
- Carbapenem
- Antifungals
61
Augmentin
Amoxicillin + Clavulanic Acid
- Clavulanic acid is a B-lactamase inhibitor
62
Possible outcomes of drug combination
- Additive effect
- Synergistic effect
- Antagonistic effect (static+cidal)
63
Chemoprophylaxis
Use of Antimicrobial drugs to prevent development of an infection in an individual at risk
(given before infection as prevention)
64
Contact with Infected person Prophylaxis
- Meningococcus: Rifampicin
- Tuberculosis: Isoniazid
65
Surgical Prophylaxis
Prevents Surgical site infections SSI especially in mucosal areas
- e.g. GI/oropharyngeal we use Cephalosporins, amoxicillin/clavulanic acid
66
Dental Prophylaxis
Prevent endocarditis in patients with prosthetic heart valves or heart damage
- Amoxicillin
67
Immunocompromised Prophylaxis
- Fluoroquinolones
- Antifungal & Antipneumocystis
68
Birth Prophylaxis
1) Group B Strep (agal.)
- Penicillin & Amoxicillin before brith
2) Neonatal Eye infections caused by STIs
- Erythromycin eye drops (traditionally silver acetate)
69
Risks of Antimicrobial drugs
- Allergy (5% penicillin)
- Direct toxicity
- Dysbacteriosis
- Candidiasis (yeast)
70
Antimicrobial Direct Toxicity
- Chloramphenicol can inhibit bone marrow function
- Tetracyclines for complex with Ca2+ and inhibit teeth & bone growth
- Aminoglycosides are Nephrotoxic, Ototoxic, Teratogenic (kidney, ear nerve toxicity)
71
Dysbacteriosis
Antibiotic that damages normal microbiota of body mostly in GI & Vagina
72
Cell wall synthesis Inhibitors
- Beta-lactams
- (Lipo)Glycopeptides
- Polypeptides
73
Beta-lactams
- Penicillins
- Cephalosporins
- Carbapenems
- Monobactams
74
B-lactams
- Consists of B-lactam ring
- Inhibits cross-linking of peptidoglycan chains by binding PBP
- More effective against Gram +
- Bactericidal
- Low side effects, can be given to children/pregnant
75
Penicillin basic Structure
B-lactam ring + 5 membered Tiazolidin ring with Sulfur
76
Penicillins
- Natural Penicillin (G/V): Narrow spec
- Aminopenicillins: Amox/Ampi, Broad spec, Better kinetics
77
Penicillin Resistance
- B-lactamase enzymes cleave B-lactam ring of AB
- We have B-lactamase inhibitors given in combination
e.g. Clavulanic Acid or Tazobactam
- Penicillinase resistant: Cloxacillin, Nafcillin
- Piperacillin for Pseudomonas
78
Cephalosporins structure
B-lactam ring + 6 membered Cephem ring with Sulfur
79
Cephalosporins
- Gen3 / Ceftriaxone: G+/-, not effective on LAME
- Gen5 / Ceftobiprole: Effective on some MRSAs
- Next Gen: Siderophore cephalo.
80
Carbapenems
- Derived from Penicillins
- Widest Spectrum / Extra Broad-spec
- Bactericidal
- Big Guns
- Mero/Erta/Doripenem
81
Extended Spectrum B-Lactamase (ESBL)
- Can break down Penicillins & Cephalosporins
- Carbapenems can still be used
82
Metallo-B-lactamase (MBL)
Can hydrolyze Penicillins, Cephalosporins, Carbapenems
- Require alternative treatment like Colistin (Polymixin)
83
Monobactams
- Narrow-spec
- Against Aerobic Gram-negative bacteria
- Rarely used
- Aztreonam
84
Bacitracin
- Polypeptide AB
- Produced by Bacillus Licheniformis
- Only topical use
- Skin infections or MRSA
85
Fosfomycin
Inhibits NAG synthesis so no Cell wall synth
- Used only for UTI
86
Inhibitors of 30S subunit of ribosomes
- Aminoglycosides
- Tetracyclines
87
Aminoglycosides types
GNATS
- Gentamycin
- Netilmycin
- Amikacin
- Tobramycin
- Streptomycin
88
Aminoglycosides info
- Bactericidal
- Kill Aerobic bacteria only
- Mainly Gram Negatives
89
Toxicity of Aminoglycosides
NOT
- Nephrotoxic
- Ototoxic
- Teratogenic
90
Tetracyclines
- Bacteriostatic
- Very wide-spec
- Chlortetracycline, Oxytetracycline, Doxycycline
- Harmful for children <8, & pregnant women (teeth/bone)
- Effects I.C & Spirochete bacteria
91
Inhibitors of 50S subunit of ribosomes
- Chloramphenicol
- Macrolides
- Lincosamides
92
Chloramphenicol
- Inhibits peptide bond formation
- Bacteriostatic
- Wide-spec
- Local application
93
Chloramphenicol side effects
- Dysbacteriosis
- May suppress bone marrow (toxicity)
- Grey baby syndrome in newborns (cant metabolize it)
94
Macrolides
- Inhibit elongation of peptide chain
- Bacteriostatic
- Broad-spec
- Safe for Pregnancy/children
- Effective against I.C bacteria
- High bacterial resistance
(Erythromycin, Azithromycin, Clarithromycin)
95
Lincosamides
- Similar to Macrolides
- Effective against Anaerobic Bacteria
(Clindamycin, Lincomycin)
96
Glycopeptides
- Inhibit cell wall synth by inhibition of cross-linking
- Narrow-spec only penetrate gram+ cause they are giant
- Bactericidal
- Used for MRSA & severe gram+
- Mostly IV cause Vancomycin cant be absorbed
(Vancomycin, Teicoplanin)
97
Glycopeptide Side effects
- Red man syndrome (nephrotoxicity)
- VRE: Vancomycin-Resistant Enterococci
98
Antimicrobial Drugs altering membrane functions
- Polymixines
- Daptomycine
99
Polymixins
- Polymixin B/E = Colistin
- Cyclic polypeptides which disintegrate cell membrane
- Gram- bacteria
- For MDR Gram-
(Nephrotoxic & CNS toxic)
100
Daptomycin
- Only Gram+ bacteria
- MDR bacteria (MRSA, VRE)
101
Nucleic Acid Synthesis Inhibitors
- Quinolones / Fluoroquinolones
- Sulfonamides
- Trimethoprim
- Metronidazole
- Rifampicin
102
Quinolones / Fluoroquinolones
- Inhibit DNA Gyrase & Topoisomerase
- Broad-spec
- Bectericidal
- Side effects: Tendon rupture, hepatotoxicity, sleep problems
Q: Nalidixic Acid
FQ: Ciprofloxacin, Levofloxacin, Moxifloxacin
103
Sulfonamides & Trimethoprim
- Inhibit Folic Acid synthesis
- Combined to form Co-trimoxazole
= Sulfamethoxazole + Trimethoprim
- Bactericidal together
104
Metronidazole
- Direct DNA breakdown
- Anaerobic Bacteria & some protozoa
- Bactericidal
Side effects: Cytotoxic metabolites, GI effects
105
Rifampicin
- DNA dep. RNA polymerase inhibitor
- For Mycobacterium or prophylaxis of meningitis
- Side effect: Orange discoloration of conjunctiva, tears, urine
106
First Line Antituberclotics
RIPE
- Rifampicin
- Isoniazid
- Pyrazinamide
- Ethambutol
107
Treatment of Tuberculosis General
- Long treatment 6-9 months
- Combination of Antituberculotics
1) 4 drugs, 2 months (RIPE)
2) 2 drugs, 4-6 months
108
Problems of Tuberculosis treatments
- MDR-TB / XDR-TB resistance
- HIV 40% death
- Side effects of drugs
- Myobacterium Tuberculosis can enter dormant state
- Compliance issues (long)
109
Tuberculosis Prophylaxis
Rifampicin
110
Types of Antimicrobial Resistance
- Natural resistance
- Acquired resistance
111
Mechanisms of Antimicrobial Resistance
- Enzymes
- Modification of Target
- Efflux pumps
- Decreased uptake
- Target overproduction
112
Natural resistance examples (gram-, anaerobic)
- Gram Neg: resistant to Vancomycin
- Anaerobic bacteria: resistant to Aminoglycosides
113
Reasons leading to antibiotic resistance
- Overuse
- Early termination
- Use in animal farming
- Spread of resistant strains
114
Categories of resistant bacteria
- Cross-resistance (same-class)
- Multidrug resistance (lots)
- Pandrug resistance (all)
115
Koch's Postulates definition
Established by Robert Koch in 1884 to show direct correlation bw certain microbe & disease
116
4 Koch's Postulates
- Microbe found in all ill subjects, & not in healthy ones
- We should be able to isolate and culture microbe from ill subject
- If healthy subject inoculated in new host it should cause same disease
- Microbe should be regained from new host & be identical to original
117
Pathogenicity
Ability of a microbe to cause infection in a given host, depends on:
- Spices of Microbe
- Strain of Microbe
- Virulence factors
- Dose of Microbe needed for infection
118
Pathogenic Variations
- Obligate
- Facultative (part of flora)
- Opportunistic
- Apathogens (saprophytes)
119
Virulence
Degree of microbe's ability to cause a disease
= Degree of pathogenicity
120
Determination of Virulence
Inoculation of microbe into susceptible host (lab)
- ID50: Infectious dose 50 (illness)
- LD50: Lethal dose 50 (killing)
121
Exotoxin definition
Toxic peptides produced inside bacteria that are highly potent & cause severe symptoms in small amounts
- Can be attenuated into toxoid vaccines
122
Characterization of Exotoxin
- Cytolytic (forms pores)
- A/B Toxins
- Superantigens (immune resp)
123
A/B Toxin types
- Neurotoxins
- Protein synth. inhibitor exotoxins
- Ion secretion increasing exotoxins (diarrhea)
124
Endotoxins def
Part of outer membrane Gram Negative bacteria
- Released at cell lysis
- Cause general symptoms (fever, hypotension)
- Cannot be attenuated
125
Lipopolysaccharide LPS
Endotoxin made up of O-antigen, Core, Lipid-A
- Lipid A is toxic component
- O-antigen provokes immune response
126
Endotoxin mode of action
Primarily through Toll-like-R 4 (TLR4) on immune cells like macrophages/dendritic cells
- Binding leads to pro-inflammatory cytokine release (TNFa, IL-1/6)
127
Endotoxin effects on Host
- Fever
- Inflammation
- Vasodilation & Increased Permeability
- Coagulation
- Septic Shock
128
LAL Test
To test for Endotoxin using blood of Horseshoe crab which clots in presence of Endotoxin
129
Infection def
Entry and replication of microorganism inside a macroorganism
130
Infection Types
- Acute (rapid, short lived)
- Subacute
- Chronic
- Latent (pathogen inactive, can reactivate)
131
Sources of Infection
- Exogenous: ill subject, reservoirs, environment
- Endogenous: flora, latent microbes
132
Portals of Entry in Infection
- Skin
- Mucous membranes
- Respiratory tract
- GI tract
- Urogenital system
133
Infection Transmission routes
- Direct/Indirect contact
- Vehicles
- Vertical spread
- Iatrogenic infection (healthcare provider or mediation)
- Nosocomial infection
134
Infection Vehicles
- Respiratory droplets
- Feco-oral route
- Arthropod vectors (insects)
- Sexual spread
135
Infection Vertical spread
- Transplacental (congenital)
- Perinatal (mother to child during delivery)
136
Infection Possible Outcomes
- Local invasion
- Dissemination (spread)
- Chronic infection
- Irregular infections (long incubation, latency, asymptomatic carriers)
137
Adhesion
Binding of bacteria to cells
- Pili
- Biofilm
- Capsules & LPS may help
138
Invasion
Use invasins that are generally enzymes that degrade host cells
- Hyaluronidase (strep, staph, clost)
- Collagenase (C.perfringens)
- Neuraminidase (GI: cholera, shigella)
139
Dissemination
Spread through blood, lymph, urogenital tract
- Streptokinase & Staphylokinase activate plasmin for fibrinolysis
140
Bacteremia
Bacteria in the bloodstream
141
Toxemia
Systemic toxin presence
e.g. in C. diphtheriae
142
Active Immunization
Method of introducing immunity by exposing the immune system to antigens through Vaccination
- Exposure of Antigen in vaccine without causing infection so we can gain immunity
143
Vaccine Types
- Live attenuated microbe vaccines
- Inactivated/Killed microbe vaccines
- Viral vector vaccines
- Subunit vaccines (pneumovax)
- Toxoid vaccines
- Nucleic acid vaccines
144
Live attenuated Microbe vaccine example
- BCG: Attenuated myobacterium bovis for prevention of TB
- MMR: Attenuated measles, mumps, rubella
145
Viral Vector Vaccine
Genetically modified harmless virus artificially modified to express antigen of a second virus
- Immunity for second virus
- e.g. COVID-19 vaccine
146
Obligatory Bacterial Infections Vaccines
- BCG
- DTaP (diph, tet, pertuss)
- Hib (H. influenza b)
- Prevenar 13 (pneum)
147
Obligatory Viral Infections Vaccines
- IPV (polio)
- VZV (varicella-chicken pox)
- MMR
- Hepatitis B
148
Non obligatory Vaccine groups
- Pneumovax 23
- Miningococcal vaccines
- Typhoid vaccines
- Cholera vaccine
149
Meningococcal Vaccines
- ACYW (polysaccharide)
- Monovalent C
- B (recombinant P)
150
Passive Immunization
Administration of pre-formed Antibodies to provide immediate protection or treatment against infection agents/toxins
151
Types of Antibodies used in passive imm
- Immunoglobulins
- Antitoxins
152
Sources of Antibodies for passive imm
- Homologous (human source)
- Heterologous (animal source)
153
Molecular Mimicry
Resemblance of molecules of host & microbes
- Decreased immune response
- Body reacts to own cells, autoimmune response
- e.g. M-protein on strep.pyogenes, N. Meningitidis B capsule like host
154
Masking
Hiding microbe from immune system
- Biofilm formation
- Capsule
- Protein-A on staph.Aureus binds Fc of antibodies
155
Antigen Shift
Change in microbe's surface antigenicity to extent that previous memory wont recognize new type
- e.g. Borelia recurrent fever, Influenza
156
Immunomodulant & Immunosuppressive effects of Microbes
- S.Aureus Panton-Valentine Leukocidin
- Myobac.TB taken up by macrophages prevents fusion with lysosome (also listeria)
- Bacterial superantigens (cytokine storm)
157
Amount of Bacteria vs Human cells
10x more bacteria than human (10^14)
158
Benefits of Human Microbiota
- Metabolism of nutrients in Gut
- Role in dev. of immune system
- Vitamin production
- Decrease pathogen attachment
(facultative pathogens)
159
Oral Cav normal Flora
LVAAT
- Lactobacillus
- Viridant strep
- Actinomyces israelii
- Anaerobic bacteria (fusobac, parvotella, porphyromonas)
- Apath. Treponema
160
GI Normal Flora
2BLEE
- Bifidobacterium
- Bacteroides
- Lactobacillus
- Enterococci
- Enterobacteriacae
161
Dysbiosis
Disruption of balance of bacteria in body leading to symptomatic diseases
- Antibiotic treatment
- SIBO (small int. bac. overgro)
- Bacterial Vaginosis (less lactob. more anae, higher pH)
- Cytolytic Vaginosis (opposite)
162
4 Stages/Steps of Sepsis
1) SIRS (Systemic Inflammatory Response Syndrome)
2) Sepsis: 2 SIRS + confirmed infect.
3) Severe Sepsis: Sepsis + end organ damage (lactate, hypotens)
4) Septic Shock (severe)
163
Systemic Inflammatory Response Syndrome Criteria (SIRS)
- Body temp too high/low
- WBC count too high/low
- Respiratory rate high
- Heart Rate high
164
SOFA Criteria
Sequential Organ Failure Assessment Criteria
- Respiration
- Coagulation
- Liver Bilirubin
- Cardiovascular
- CNS
- Renal Creatinine
165
Sepsis & Gram Negative Bacteria
Gram Neg, LPS, Cytokine storm, Increased vascular permeability, Hypotension, DIC, Multi-organ Failure
- Lung ARDS
- Intestines leaky, bacteria enter
- Kidney VC (less urine, necrosis)
- Heart (reduced cont.)
166
Bacterial Multiplication
Binary Fission
- Asexual
- 2 identical daughter cells
167
Generation Time
Time it takes for bacteria population to double in number through Binary fission
~ 20-40 mins
(myobacteria need 20h)
168
Bacterial Growth Curve Phases
- Lag Phase
- Log Phase
- Stationary phase (dividing=death)
- Death phase
169
Forms of Bacterial Growth
- Planktonic (free-floating, in liquid)
- Biofilm
- Colony
170
Hemolysis Types
- a-Hemolysis: Partial, Greenish zone
- B-Hemolysis: Complete, clear zone
- y-Hemolysis: No hemolysis
171
Swarming Culture
Instead of forming colonies like little specs the bacteria (motile) spreads on agar (proteus mirabilis)
172
Nosocomial / Iatrogenic Infections
- Intravascular Catheter related BS infection
- Ventilator Associated Pneumonia
- SSIs
- Catheter Associated UTIs
- C.dificile infection on AB treated patients
