Are viruses, viroids, and prions considered cells?
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No, they are not cells and are in neither category.
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Are viruses, viroids, and prions considered cells?
No, they are not cells and are in neither category.
How do flagella contribute to bacterial motility?
They rotate to propel the bacterium through its environment.
What is horizontal transmission of genes between bacteria called?
Conjugation.
How many chromosomes do most bacteria have?
1 chromosome.
What process explains the incorporation of bacteria into eukaryotic cells?
Endosymbiosis.
What is the function of flagella in bacteria?
To provide motility and enable movement.
What is the Ziehl-Neelsen stain used for?
Detection of Mycobacterium tuberculosis and a few other organisms with high lipid/wax content in their cell wall.
What type of organisms are primarily made up of prokaryotic cells?
Bacteria and Archaea.
What are inclusions in bacteria?
Reserve deposits of nutrients in membrane-bounded vacuoles.
What is another name for the plasma membrane?
Cytoplasmic membrane.
Why are the differences in plasma membranes important?
They affect the structure and function of cells.
What is a key strategy for preventing C. difficile infections?
Implementing strict hand hygiene practices.
What is a major cause of nosocomial infections globally?
Clostridium difficile.
What are nonconventional treatments for Clostridium difficile?
Probiotics and fecal implants.
What is a prokaryotic cell?
A type of cell that lacks a nucleus and membrane-bound organelles.
What is the classification of G+ streptococci?
Gram-positive cocci.
What is the function of endospores for bacteria?
Survival.
What type of membrane do prokaryotes have?
Phospholipid cytoplasmic membrane.
What is a key characteristic of Gram-positive (G+) cell walls?
They have a thick peptidoglycan layer.
What is C. difficile associated with?
It is associated with antibiotic-associated diarrhea and colitis.
What is AAD?
Antibiotic associated diarrhea.
What role does environmental cleaning play in preventing C. difficile?
Regular cleaning and disinfection of surfaces can reduce transmission.
What is a characteristic of Mycoplasma sp that affects its staining?
It contains large amounts of sterols and has no peptidoglycan.
Where do C. difficile spores germinate?
In the intestine after contact with bile acids.
What effect do the exotoxins TcdA and TcdB have on the intestinal epithelium?
They cause it to leak, leading to watery diarrhea.
What type of organelles do prokaryotic cells lack?
Membrane-bound organelles.
What type of organisms are classified as prokaryotes?
Bacteria.
What type of spores does Clostridium difficile produce?
Endospores.
Which other organism can be detected using the Ziehl-Neelsen stain?
Cryptosporidium, a parasite.
Which types of bacteria produce endospores?
Clostridium and Bacillus.
What is the main difference between prokaryotes and eukaryotes?
Prokaryotes lack a nucleus, while eukaryotes have a defined nucleus.
What is the significance of the thick peptidoglycan layer in Gram-positive bacteria?
It provides structural support and protection against environmental stress.
How does susceptibility to penicillin differ between Gram negative and Gram positive organisms?
Gram negative organisms are generally less susceptible to penicillin, while Gram positive organisms are more susceptible.
What type of organisms are primarily made up of prokaryotic cells?
Bacteria and archaea.
Are C. difficile spores considered 'living'?
No, spores are not 'living'.
What are conventional treatments for Clostridium difficile?
Antibiotics like vancomycin and metronidazole.
Do prokaryotic cells have a nucleus?
No, they do not have a nucleus.
What is the origin of mitochondria in eukaryotic cells?
Mitochondria originated from bacteria through endosymbiosis.
What role do mitochondria play in eukaryotic cells?
They are involved in energy production through cellular respiration.
When is the Z-N stain used?
It is used for identifying acid-fast bacteria.
What is a key structural difference between Gram negative and Gram positive organisms?
Gram negative organisms have a thin layer of peptidoglycan, while Gram positive organisms have a thick layer.
Do prokaryotic cells have a defined nucleus?
No, they do not have a defined nucleus.
Why do children under 2 years not show symptoms of C. difficile infection?
They may harbor the bacterium but never have symptomatic infection.
What are the components of peptidoglycan?
Polymer of N-acetylmuramic acid and N-acetylglucosamine linked with peptides.
What is the typical size range of eukaryotic cells?
10 - 100 μm.
What is the function of a capsule or glycocalyx in bacteria?
Evasion from white blood cells and sometimes attachment to cells.
What is the function of pili/fimbriae in bacteria?
Attachment to cells/tissues.
What is a key feature of prokaryotic cells?
They have a simple structure compared to eukaryotic cells.
What are plasmids?
Small circular pieces of DNA that code for a restricted number of proteins.
What is CDAD?
Clostridium difficile associated diarrhea.
What is the size range of prokaryotic cells?
Typically 0.1 to 5.0 micrometers in diameter.
What type of organism is C. difficile?
Strict anaerobe, Gram-positive bacillus, spore-forming.
How do teichoic and lipoteichoic acids affect bacterial cells?
They project outwards and cause cells to have a negative charge.
What type of organisms does the Ziehl-Neelsen stain target?
Organisms with high lipid/wax content in their cell wall.
What is the nuclear area of bacteria called?
Nucleoid.
What are resting cells with no metabolism called?
Endospores.
What types of environmental conditions can endospores resist?
Heat, drying, UV radiation, and chemicals.
What unique component does the human cell plasma membrane contain?
Cholesterol.
How do Gram-positive and Gram-negative bacteria differ in their response to Gram staining?
Gram-positive bacteria retain the crystal violet stain, appearing purple, while Gram-negative bacteria do not and appear pink after counterstaining.
Which bacteria is an exception to Gram staining due to its cell wall composition?
Mycobacterium sp, such as M. tuberculosis.
What is the NAP1/B1/027 strain of C. difficile known for?
Being more virulent, producing 16 times more toxin and having a 3-4 times higher mortality rate.
What is lipopolysaccharide (LPS) associated with?
The outer membrane of Gram-negative bacteria.
Do eukaryotic cells have a true nucleus?
Yes, they have a true nucleus.
What is an axial filament?
A structure found in spirochaetes that consists of flagella located inside the cell wall.
In which type of bacteria are axial filaments primarily found?
Spirochaetes.
What is the ribosome size in bacteria?
70S (composed of 2 subunits).
What are G- diplococci?
Gram-negative cocci that occur in pairs.
How do endospores differ from capsules?
Endospores are resting cells with no metabolism, while capsules are protective layers around some bacteria.
What is the primary purpose of Gram staining?
To differentiate between Gram-positive and Gram-negative bacteria.
What type of bacteria are more resistant to antibiotics, G+ or G-?
Gram-negative bacteria are generally more resistant due to their outer membrane.
How can antibiotic use be managed to prevent C. difficile infections?
By minimizing unnecessary antibiotic prescriptions.
What is a key feature of prokaryotic cells?
They have a simple structure compared to eukaryotic cells.
What do the exotoxins produced by vegetative C. difficile bacteria damage?
Intestinal mucosa, leading to cell death and leakage of the epithelium.
How long can C. difficile spores survive in the environment?
Months.
What are teichoic and lipoteichoic acids associated with?
Only Gram-positive bacteria.
What is a key characteristic of prokaryotic cells?
They are small unicellular organisms.
Which treatment for Clostridium difficile has the best success rate?
Fecal implants.
What is the function of ribosomes in bacteria?
Site of protein synthesis.
What materials are found within the hard coat of endospores?
Genetic material, dipicolinic acid, and peptidoglycan.
What color do Gram negative organisms stain?
Pink/red.
Why does Mycobacterium tuberculosis not stain well with Gram's stain?
It has large amounts of mycolic acid in its cell wall, preventing stain penetration.
What serious condition can result from C. difficile infection?
Toxic megacolon (gangrene of intestines).
What are the names of the two main cytotoxins produced by C. difficile?
TcdA (toxin A) and TcdB (toxin B).
What is the structure of peptidoglycan?
A lattice structure like a mesh.
What is the structure of the flagella in prokaryotic cells?
Simple flagella.
What type of bacteria is Clostridium difficile?
Anaerobic Gram positive rod that produces endospores.
What is the role of the sex pilus in bacteria?
Transfer of plasmid.
What is the condition associated with abnormal intestinal mucosa?
Pseudomembranous colitis (PMC).
What shape are G+ rods classified as?
Bacilli.
What does pure culture refer to in microbiology?
A culture containing only one type of organism.
What is a key piece of evidence supporting the bacterial origin of mitochondria?
Mitochondria have their own DNA, which is similar to bacterial DNA.
What are the key aspects of bacterial classification?
Families, size, and naming.
What structural component is found in the outer membrane of Gram-negative bacteria?
Lipopolysaccharides (LPS).
What color do Gram positive organisms stain?
Dark blue/purple.
Which bacteria lacks a cell wall and does not stain with Gram's stain?
Mycoplasma sp, such as M. pneumoniae.
What is a common consequence of C. difficile infections?
Dehydration.
What is the function of Lipid A in LPS?
It acts as an 'endotoxin' and anchors in the bacterial outer membrane.
Which organisms are classified as eukaryotes?
Fungi, plant cells, protozoa, metazoans, and human cells.
What does PMC stand for?
Pseudomembranous colitis.
What type of bacteria are G- rods?
Gram-negative rods.
What components are found in the plasma membrane of eukaryotes?
Some phospholipids, carbohydrates, and sterols.
What is a key characteristic of Gram-negative (G-) cell walls?
They have a thin peptidoglycan layer and an outer membrane.
What structures are absent in Gram positive organisms?
Lipopolysaccharide, outer membrane, and periplasm.
Why is patient isolation important in preventing C. difficile spread?
It helps to contain the infection and prevent transmission to others.
What is a potential outcome of severe C. difficile infection?
Death.
What is CDT in relation to C. difficile?
C. difficile binary toxin, often found in epidemic strains.
What substances do not inactivate C. difficile spores?
Antibiotics, alcohols, or alcohol-based hand cleansers.
How do prokaryotic cells reproduce?
Through binary fission.
What amino acid do all proteins in prokaryotes begin with?
Formylmethionine.
What is found in the plasma membrane of fungal cells?
Ergosterol.
What are the main components of bacterial structure?
Cell wall, cell membrane, cytoplasm, and genetic material.
Do Gram negative organisms contain teichoic acid?
No, Gram negative organisms do not contain teichoic acid.
What does AAC stand for?
Antibiotic associated colitis.
What should healthcare facilities implement to prevent C. difficile infections?
Infection control protocols and surveillance.
How is C. difficile transmitted?
Fecal-oral transmission.
Do prokaryotic cells have a nuclear membrane?
No, they lack a nuclear membrane and nucleoli.
What type of reproduction occurs in eukaryotic cells?
Mitosis and meiosis (sexual reproduction).
What amino acid do all proteins in eukaryotes begin with?
Methionine.
What is N. meningitidis known for?
It is a bacterium that can cause meningitis.
What unique component is found in Gram negative organisms?
Lipopolysaccharide.
What is a prokaryotic cell?
A type of cell that lacks a nucleus and membrane-bound organelles.
What is PMC?
Pseudomembranous colitis.
How do spores of C. difficile survive stomach acid?
They are ingested and not affected by stomach acid.
What is a notable characteristic of the NAP1/B1/027 strain regarding antibiotic resistance?
High resistance to fluoroquinolone antibiotics.
What does the O antigen in LPS do?
Projects outward from the cell.
What is the ribosome size in eukaryotic cells?
80S, except for mitochondria which are 70S.
What is a significant mutation found in the NAP1/B1/027 strain?
A mutation in the tcdC gene, which regulates toxin production.
What is the typical size range of prokaryotic cells?
0.2 - 2.0 μm.
What type of chromosomes do eukaryotic cells have?
Multiple linear chromosomes.
