Intro to bacteriology Flashcards
Describe the difference in pharyngitis presentation between a viral infection and a bacteria infection?
- Virus
- red, swollen tonsils
- red throat
- Bacteria
- red swollen tonsils
- red throat
- swollen uvula
- whitish spots
- gray furry tongue
What 5 charactersitics should you consider when diagnosing a bacterial infection?
- general structure
- prevalence and mode of transmission
- initial colonization and immune evasion
- mechanism of tissue damage and pathogenesis
- labs and other means of diagnosis
What is the only cytoplasmic organelle present in prokaryotes?
ribosomes
Where is genetic information stored in a bacteria?
in a circular chromosome
genetic material can also be extrachromosomal (plasmid)
Describe the differences in cell wall composition for gram (+) and gram (-) bacteria? What molecule constitutes the cell wall? Why is this an important distinction?
- gram (+)
- thick (20-80nm)
- external to cell membrane
- gram (-)
- thin (5-10nm)
- between inner and outer membrane
Peptidoglycan; it is an excellent antimicrobial target
Describe the progression of gram staining.
- Stain with Crystal Violet
- Stain wtih Grams Iodine
- Decolorize
- gram (+) will remain purple
- couterstain with saffrin red
- gram (-) will be red
Name the types of bacterial cells shown in the image
Name the terminiology used to describe bacteria with the following characteristics
- grows in the presence of oxygen
- grow with or without oxygen
- grow in the absence of oxygen
- special growth requirement
- simple growth requirement
- requires CO2
- salt loving
- aerobic
- facultative
- anaerobic
- fastidious
- non-fastidious
- capnophilic
- halophilic
Which two molecules are found exclusively in the cell wall of gram positive bacteria? What is their function for the bacterial cell?
Teichoic acid (TA) and Lipotechoic acid (LTA)
promote attachment to mamalian cell
important for viability, virulance, and serotyping
How can protein synthesis be targeted by antibiotics? In what cases would you choose to target protein synthesis opposed to bacterial cell wall?
bacteria and eukaryotes have different ribosome
- bacteria: 70S
- eukaryote: 80S
you would choose to target protein synthesis in a blood infection (cells are not lysed so toxins are not released)
What are bacterial capsules composed of? Why are they important?
loose polysaccharide layer
promote adherence, anti-phagocytic, poor antigen
What type of bacteria are able to form spores and endospores? What are spores and endospores?
gram positive
non-replicating entity, DNA and other essentials inside a thick coat
it is considered an “endospore” when it is located inside a vegetative bacteria
Name the flagella type associated with the following descriptions
- one flagella
- multiple flagella on one end of the bacteria
- flagella on opposite ends of a bacteria
- When they are clustered all over the bacterial surface
What is the purpose of flagella?
- monotrichous
- lophotrichous
- amphitrichous
- peritrichous
Flagella alow the bateria to move away from poisons or towards food
What are the hair-like projections that are shorter and thinner than flagella, that protrude through the cell wall and determine cellular adhesion?
fimbriae (F-antigens)
What is the membrane component only present in gram negative bacteria? What happens to them after cell death? What is the body’s respone? What is the most toxic component?
Lipopolysaccharide (LPS)
Integral part of outer cell membrane, released after cell death
When host senses LPS, it turns on every defense
Lipid A
Name and explain the indicated pheses of bacterial cell growth
