2018/2019 SAQ Flashcards
What are the 4 phases of microbial growth in batch culture?
- Lag Phase
- Log Phase
- Stationary Phase
- Death Phase
- Lag Phase
What are the 4 phases of microbial growth in batch culture?
- Microorganism adjusting to new environment
- Preparing to divide
- Little/no increase in cell number
- Slow growth rate
2.Log Phase
What are the 4 phases of microbial growth in batch culture?
- Also known as exponential phase
- Microorganism grow and divide at exponential rate
- Logarithmic increase in cell number
- Population doubles in specific amount of time= **generation time **
3.Stationary Phase
What are the 4 phases of microbial growth in batch culture?
- Growth rate slows down
- depletion of nutrient
- Accumulation of waste products
- Population size reaches a maziumum
- remains constant
Death Phase
What are the 4 phases of microbial growth in batch culture?
- Number of microorganisms decrease
- Lack of nutrients
- Accumulation of toxic waste products
- death rate exceed growth rate
- decline in population size
List the 3 motilities of bacteria
Gliding
Twitching
Swarming
Explain Gliding Motility
Cells move smoothly along a surface
Exact mechanism not well understood
Invoves secretion of a slime trail that bacterium moves along
Explain twitching motility
Extention and retraction of pili (think, hair-like appendages)
To pull the cell along a surface
Important: colonization of surfaces and biofilm formation
Explain Swarming motility
Cell move in a coordinated fasion across a surface
In responseto physical or chemical signals
Highly motile
Multiple flagella allow them to move quickly and efficiently
4 examples of polymers involved in specific ireversible adhesion of bacteria to surfaces
- Flagella
- Fimbriae
*Lipopolysaccharides (LPS) - Stalks
4 examples of polymers involved in specific ireversible adhesion of bacteria to surfaces
- Extracellular polymeric substances 9EPS)
- Capsular polysaccharides
- Fimbriae or Pilli
- Adhesins
Polymer
EPS
- secreted by bacteria
- form matrix around cells
- role in bioflm formation and adhesion to surfaces
Capsular polysaccharides
- Complex carbohydrates
- surface of some bacteria
- bacterial adesion to srufaces
- > provide sticky surface for attachment
Fimriae or Pilli
- Hair like appendages
- surface of bactia
- adhesion to surfaces
- > bind to spcific receptors on host cells
- allow attachment of bacteria to and colonize surface
Fimriae or Pilli
- Hair like appendages
- surface of bactia
- adhesion to surfaces
- > bind to spcific receptors on host cells
- allow attachment of bacteria to and colonize surface
Adhesins
- Bacterial surface proteins
- Adhesins bind to receptoron host cells, extracellular matrix proteins, bacterial cells
- allow attachmet of bacteria, colonize surfaces
What is the formal phylum name of sac fungi?
Ascomyota
What is the formal phylum name of club fungi?
Basidiomycota
Key difference betweek Ascomycota and Basidomycota in terms of sporecontaining structures?
Ascomycota
* Produce spores inside sac-like structures (asci)
* Containing within fruiting body = ascocarp
* enclosed
Basidiomycota
* produce spores on the surface of club-shaped structures= basidiocarp
* exposed on surface
-> important in classification, identification
Give the 2 scientific names of 2 fungal species that benefit humans
- Saccharomyces cerevisiae
- Penicilium chrysogenum
2 fungal species threath to humans
Aspergillus fumigatus
Candida albicans
Fungi: Saccharomyces cerevisae
Benefit humans
- food industry
- baking, brewing, wine making
- biofuel production
- pharmaceuticals
- industrial enzymes
Fungi-penicillium chrysogenum
benefit to humans
* species of mold:antibiotic penicillin
* widely used to treat bacterial infections
Fungi- Aspergillus fumigatus
Threath to human health
* mold: severe respiratory infections
* worsed with weakened systems
Fungi- Aspergillus fumigatus
Threath to human health
* mold: severe respiratory infections
* worsed with weakened systems
Fungi- Candida Albicans
threat to humans
- species of yeast
- oral thrush
- vaginal yeast infections
- serious systemic infections in immunocompromised individuals
Types of viral transmission
- Horizontal transmission
- Vertical transmission
Horizontal viral transmission
- Spread of virus from one individual to another within the same generation
- > how: direct/indirect contact: with infected bodily fluids, respiratory droplets, fomitea (objects carry infectious agents)
Example
- air-borne transmission
- via contaminated syrfaces or object
Vertical viral transmission
- Mother to offspring
- during pregnancy
- childbirth
- breastfeeding
How
-transplacentallu (across placenta)
- Perinatally (during childbirth)
Result
- congenital infections
- infections n newborns
How is influenza virus transmitted
Horizontal transmission
- repiratory droplets
- diect contact with infected individuals
- contaminated surfaces
- air over short distance
Vertical transmission - rare
- associations: maternal influenze infection during pregnancy
- increased risk of adverse pregnancy oucome
- respiratory infection in newborns
Morphology
What are the main features of the Ebola virus?
- filamentous, thread like shape
- electron microscope
- virus particles 800-100nm
- 80nm diameter
Envelope
What are the main features of the Ebola virus?
- envelope derived from host cell membrane surround virus particle
- glyoproteins: viral entry ->host cell
Genome
What are the main features of the Ebola virus?
- single stranded RNA
- 19kb
- encodes structural and non-structural proteins
Pathogenesis
What are the main features of the Ebola virus?
- fatal hemorrhagic fever in humans and non human primates
- entry: via mucous membanes/breals in the skin and replication in tissues and organs
- widespread damage
- triggers hist immune response
- lead to inflammation anhd organ failure
Transmission
What are the main features of the Ebola virus?
- direct contact with the blood, body fluids, tissues of infected individuals or animals
- contact with contaminated surfaces/objects
- person t person thorugh close contact with infected individuals (caring for/liing with infected indivual.
Name 2 pathogens associated with Acute necrotizing ulcerative gingivitis (Trench mouth)
- Porphyromonas gingivalis
- Prevotella intermedia
Pathogen of trench mouth
- Porphyromonas gingivalis
- gram negative
- anaerobic
- associated with periodontal disease, including ANUG
- produces virulene factors: proteases, LPS - damage to host tissue and cause inflammation
- Prevotella intermedia
- gram negative
- also associated with peridontal disease , includinf ANUG
- Produces enzmes/toxins contribute to tissue destrction and immune evasion
Urinary catheter infection
- Medical procedure
- insertion of a flexible tube into bladder through urethra
- why> drain urine
- associated with increased risk of urinart tract infection (UTI)
- > Those with long-term catheterization
Important pathogens associated with urinary catheter infection- Keep C
- Escherichia coli
- Klebsiella pneumoniae
- Pseudomonas aeuruginosa
- Enterococcus feacalis
- Candida albicans
bacteria
Escherichia coli
Important pathogens associated with urinary catheter infection
- gram negative
- catheter associated UTIs
- colonize catheter surface
- form biofilm
- hard to treat with antimicrobial agents
Bacteria
Klebsiella pneumoniae
Important pathogens associated with urinary catheter infection
- gram negative
- catheter associated UTIs
- patientswith underlying medical condtions: diabetes, compromised immune function
Bacteria
Pseudomononas aeruginosa
Important pathogens associated with urinary catheter infection
- gram negative
- opportunistic pathogen
- colonize catheter surface
- form biofilm
- persistent infection
- treatment failure
Bacteria
Enterococcus faecalis
Important pathogens associated with urinary catheter infection
- gram positive
- catheter associated UTIs
- patients exposed to antibiotics/compromised immune function
Fungus
Candida albicans
Important pathogens associated with urinary catheter infection
- opportunistic
- colonize cather surface
- form biofilm
- persistent infection
- treatment failure
- long term catheterization
- exposed to borad antibiotics
List 4 symptoms of meningitis
- Fever
- Headache
- Stiff neck
- Altered mental status
List 4 symptoms of meningitis
- Fever
- Headache
- Stiff neck
- Altered mental status
Neisseria gonorrhoeae
- gram-negative
- diplococcus bacterium
- sexually transmitted infection
List 4 virulence factors found Neisseria gonorrhoeae
virulence factors found Neisseria gonorrhoeae
- Pili
- Porin
- Lipooligosaccharide (LOS)
- Proteases
Pili
virulence factors found Neisseria gonorrhoeae
- produces long thin appendages= pilli
- > undergo genetic variation
- helps bacteria evade host immune system
Porin
virulence factors found Neisseria gonorrhoeae
- produces porin protein
- penetrate and survive within himan cells
- resist host immune system
- contributes antibiotic resistance
Lipooligosaccharide (LOS)
virulence factors found Neisseria gonorrhoeae
- Produces complex LOS
- Trigger inflammatory response in host
- contributes to symptoms of infection
Proteases
virulence factors found Neisseria gonorrhoeae
- break down host proteins
- damage to host tissues
- evade host immune system by degrading antibodies and complement proteins
Lower urinary tract infection
Explain the differenced between lower and upper urinary tract infection
Lower UTIs
* affects bladder and urethra
* symptom:
* Pain/burning urination
* urgency to urinate
* coudy/bloody urine
* strong-smelling urine
* pain in lower adbomen/back
Low UTIs - how
-bacteria enter uretra and travell up into thebladder
Upper urinary tract infection
Explain the differenced between lower and upper urinary tract infection
- Affect kidneys and ureters
Symptoms
* High fever
* Chills and shivering
* nausea and vomiting
* pain int he upper back or side
* flank pain
* blood in the urine
How
* bacteria enter bloodstream
* travrl to kidneys
- More serious than lower UTIs
- seek promt medical attention
Upper urinary tract infection
Explain the differenced between lower and upper urinary tract infection
- Affect kidneys and ureters
Symptoms
* High fever
* Chills and shivering
* nausea and vomiting
* pain int he upper back or side
* flank pain
* blood in the urine
How
* bacteria enter bloodstream
* travrl to kidneys
- More serious than lower UTIs
- seek promt medical attention
