NSC2500 Questions With All Correct Answers
Microbiota correct answer -The term for the microbes that are normally
present in and on the human body; usually beneficialConsists predominately
of bacteria, viruses, Archaea, microeukaryotes
Microbiome correct answer -(sometimes metagenome) is different and is
made up of the genes and gene products of the microbial populations in the
body
Bacteria correct answer -Prokaryotic - very simple cells that are
unicellular with no nuclear membrane, mitochondria, Golgi bodies or
endoplasmic reticulum, reproduce by binary fission (can be every 20 mins!)
(microbiology) single-celled or noncellular spherical or spiral or rod-shaped
organisms lacking chlorophyll that reproduce by fission
Prokaryote correct answer -A unicellular organism that lacks a nucleus
and membrane bound organelles
Archaea correct answer -One of two prokaryotic domains, the other being
Bacteria.
Lack nuclei (like prokaryotes), have unique membrane (unlike prokaryotes);
able to live in extreme environments; ? Have a role in obesity?
Eukaryote correct answer -A complex cell that contains a nucleus and
membrane bound organelles
Virus correct answer -A tiny, nonliving particle that invades and then
reproduces inside a living cell.
NOT a cell but a PARTICLE, genetic material DNA or RNA (not both); obligate
intracellular parasite (takes over invaded cell's metabolic machinery)
• >100,000,000 million spp.
• Acellular, non-living?
• +20nm diameter
• Simple structure
• Important disease agents eg. AIDS, SARS, Hepatitis, Herpes
,opportunistic pathogens correct answer -Microorganisms that do not
normally cause disease but may do so if moved to a new site (eg wound, burn)
or in the immunocompromised (eg the elderly, those undergoing
chemotherapy etc)
Where is it normal to bacteria correct answer -Upper respiratory tract,
mouth, trachea, bronchi, lung, skin, vagina, anus, large intestine, pancreas,
stomach
When does the presence of bacteria indicate a disease state? correct answer
-
How does Fungi, parasites and algae all cause disease ? correct answer -
What are the two sources of infection in the community ? correct answer -
HAI
Non - HAI (community)
HAI correct answer -Healthcare-associated infection - • Infection that is
not apparent or incubating at the time of admission but appears at least 48
hours post admission or within a specified time after discharge
• Causative agents: Bacteria (most), fungal, then viruses
• Sites of infection generally include: Urinary tract; Surgical wounds; Lower
respiratory tract;
Skin; Blood
• Influenced by: Person's age; Operation type and site; Degree of
immunosuppression; Catheterisation or cannula insertion (length of time)
Non - HAI (community) correct answer -• Can be from endogenous
infection; Transient microflora; True pathogen; Opportunistic pathogen;
Environmental influences; Secondary infection; transmission from surfaces,
community, water etc
• Can be exacerbated by overuse and inappropriate use of broad spectrum
antibiotics (may antibiotic resistance)
Fungi correct answer -Yeast and filamentous fungi
• 100,000+ spp. (species)
• Filamentous (mycelial), walled, heterotrophs
• Some are disease causing eg. Candida, Cryptococcus, Aspergillus
,• Filamentous fungi (mould) and yeast - main agents of human disease
• Filamentous fungi:
• Aerial hyphae, unique spore morphology, spores ubiquitous (eg Aspergillus
fumigatus) • Yeasts:
• round, unicellular, larger than bacteria, dimorphic (eg Candida albicans)
Parasites correct answer -An organism that lives in or on another
organism, deriving nourishment at the expense of its host, usually without
killing it
• Helminths and arthropods
• Protozoa: Unicellular eukaryotic organisms
Algae: correct answer -Aquatic organisms - limited disease?
The difference between Prokaryotic and Eukaryotic Cells correct answer -
Prokaryotic- Unicellular, Very simple structure
Eukaryotic - Unicellular (protozoa, yeasts)
OR Multicellular (algae, fungi, more complex plants and animals)
Shapes of bacterial cells correct answer -Coccus (circles)
Rod (bacilli)
Spirillum (corkscrew)
Taxis: correct answer -movement toward or away from chemical or
physical conditions
• Chemotaxis: movement in response to chemical agents • Phototaxis:
movement in response to light
Bacteria move by correct answer -= flagella
• Simple flexing
• Rotation/corkscrewtypemotion
• Many Bacilli have flagella; most Cocci have no flagella
Bacterial Growth requirements correct answer -• Oxygen
• Moisture
• Temperature
• pH
• Nutrients
, • Some microorganisms can survive extreme environments
Bacterial virulence factors correct answer -Attachment • Capsule
• Pili/fimbriae
• Tip organelles • Adhesins
Toxin production
• Bacterial toxins
• Some are extremely potent at low concentrations (eg C. botulinum toxin)
Invasion
• Few bacteria are able to colonise host surfaces
• Degrade cells using proteases and plasminogen binding proteins
• Trick cell into internalising using fibronectin binding proteins
Evasion of host immune system
• Hide from immune system
• Proteases to prevent chemotaxis
• Antigenic variation (serotypes)
• Molecular mimicry (also creates autoimmune issues)
• Prevent phagocytosis
• Capsules
• Escape from 'digestion' process
• DNase to degrade Neutrophil Extracellular Traps (NETs)
• Proteases which destroy phagocytes
• Biofilm formation
Susceptibility
• True pathogens
• Opportunistic pathogens • Commensals
• Age
• Immune status
• Genetic factors
• Surgery
• Pre-existing disease
• Chemo/immunosuppressive drugs • Other infections
• Stress
Microbiota correct answer -The term for the microbes that are normally
present in and on the human body; usually beneficialConsists predominately
of bacteria, viruses, Archaea, microeukaryotes
Microbiome correct answer -(sometimes metagenome) is different and is
made up of the genes and gene products of the microbial populations in the
body
Bacteria correct answer -Prokaryotic - very simple cells that are
unicellular with no nuclear membrane, mitochondria, Golgi bodies or
endoplasmic reticulum, reproduce by binary fission (can be every 20 mins!)
(microbiology) single-celled or noncellular spherical or spiral or rod-shaped
organisms lacking chlorophyll that reproduce by fission
Prokaryote correct answer -A unicellular organism that lacks a nucleus
and membrane bound organelles
Archaea correct answer -One of two prokaryotic domains, the other being
Bacteria.
Lack nuclei (like prokaryotes), have unique membrane (unlike prokaryotes);
able to live in extreme environments; ? Have a role in obesity?
Eukaryote correct answer -A complex cell that contains a nucleus and
membrane bound organelles
Virus correct answer -A tiny, nonliving particle that invades and then
reproduces inside a living cell.
NOT a cell but a PARTICLE, genetic material DNA or RNA (not both); obligate
intracellular parasite (takes over invaded cell's metabolic machinery)
• >100,000,000 million spp.
• Acellular, non-living?
• +20nm diameter
• Simple structure
• Important disease agents eg. AIDS, SARS, Hepatitis, Herpes
,opportunistic pathogens correct answer -Microorganisms that do not
normally cause disease but may do so if moved to a new site (eg wound, burn)
or in the immunocompromised (eg the elderly, those undergoing
chemotherapy etc)
Where is it normal to bacteria correct answer -Upper respiratory tract,
mouth, trachea, bronchi, lung, skin, vagina, anus, large intestine, pancreas,
stomach
When does the presence of bacteria indicate a disease state? correct answer
-
How does Fungi, parasites and algae all cause disease ? correct answer -
What are the two sources of infection in the community ? correct answer -
HAI
Non - HAI (community)
HAI correct answer -Healthcare-associated infection - • Infection that is
not apparent or incubating at the time of admission but appears at least 48
hours post admission or within a specified time after discharge
• Causative agents: Bacteria (most), fungal, then viruses
• Sites of infection generally include: Urinary tract; Surgical wounds; Lower
respiratory tract;
Skin; Blood
• Influenced by: Person's age; Operation type and site; Degree of
immunosuppression; Catheterisation or cannula insertion (length of time)
Non - HAI (community) correct answer -• Can be from endogenous
infection; Transient microflora; True pathogen; Opportunistic pathogen;
Environmental influences; Secondary infection; transmission from surfaces,
community, water etc
• Can be exacerbated by overuse and inappropriate use of broad spectrum
antibiotics (may antibiotic resistance)
Fungi correct answer -Yeast and filamentous fungi
• 100,000+ spp. (species)
• Filamentous (mycelial), walled, heterotrophs
• Some are disease causing eg. Candida, Cryptococcus, Aspergillus
,• Filamentous fungi (mould) and yeast - main agents of human disease
• Filamentous fungi:
• Aerial hyphae, unique spore morphology, spores ubiquitous (eg Aspergillus
fumigatus) • Yeasts:
• round, unicellular, larger than bacteria, dimorphic (eg Candida albicans)
Parasites correct answer -An organism that lives in or on another
organism, deriving nourishment at the expense of its host, usually without
killing it
• Helminths and arthropods
• Protozoa: Unicellular eukaryotic organisms
Algae: correct answer -Aquatic organisms - limited disease?
The difference between Prokaryotic and Eukaryotic Cells correct answer -
Prokaryotic- Unicellular, Very simple structure
Eukaryotic - Unicellular (protozoa, yeasts)
OR Multicellular (algae, fungi, more complex plants and animals)
Shapes of bacterial cells correct answer -Coccus (circles)
Rod (bacilli)
Spirillum (corkscrew)
Taxis: correct answer -movement toward or away from chemical or
physical conditions
• Chemotaxis: movement in response to chemical agents • Phototaxis:
movement in response to light
Bacteria move by correct answer -= flagella
• Simple flexing
• Rotation/corkscrewtypemotion
• Many Bacilli have flagella; most Cocci have no flagella
Bacterial Growth requirements correct answer -• Oxygen
• Moisture
• Temperature
• pH
• Nutrients
, • Some microorganisms can survive extreme environments
Bacterial virulence factors correct answer -Attachment • Capsule
• Pili/fimbriae
• Tip organelles • Adhesins
Toxin production
• Bacterial toxins
• Some are extremely potent at low concentrations (eg C. botulinum toxin)
Invasion
• Few bacteria are able to colonise host surfaces
• Degrade cells using proteases and plasminogen binding proteins
• Trick cell into internalising using fibronectin binding proteins
Evasion of host immune system
• Hide from immune system
• Proteases to prevent chemotaxis
• Antigenic variation (serotypes)
• Molecular mimicry (also creates autoimmune issues)
• Prevent phagocytosis
• Capsules
• Escape from 'digestion' process
• DNase to degrade Neutrophil Extracellular Traps (NETs)
• Proteases which destroy phagocytes
• Biofilm formation
Susceptibility
• True pathogens
• Opportunistic pathogens • Commensals
• Age
• Immune status
• Genetic factors
• Surgery
• Pre-existing disease
• Chemo/immunosuppressive drugs • Other infections
• Stress
