Introduction to Microbiology and Infectious Diseases Flashcards
The microbiome refers to bacteria alone, not fungi
F
25% of the world population have latent infection with TB
T
There are about 5 new cases of TB infection every day in Singapore
T
Childhood immunization includes tetanus diphtheria and pertussis
T
Adult immunisation includes pneumococcal vaccine for people over 65yrs
T
The chromosome in prokaryotes is a linear strand of DNA
F
Prokaryotes have membrane bound organelles
F
The prokaryotic ribosome is 70s
T
Bacteria multiply by binary fission
T
Bacteria measure about 2-4 millimeters (mm)
F
Gram positive bacteria have an outer cell membrane
F
Most bacterial cell walls contain peptidoglycan
T
Bacterial cell shapes are determined by the cell membrane
F
Gram positive bacteria stain pink with the gram stain
F
Lipo-polysaccharide is found in the inner cell membrane
F
Plasmids are non-chromosomal pieces of DNA
T
Plasmids may encode genes for resistance to antibiotics
T
Plasmids may encode genes for pathogenicity factors
T
Conjugation refers to the uptake of plasmids from the environment
F
Bacteriophages may spread resistance by transduction of plasmids
T
Mycoplasma spp. are resistant to drugs that act on peptidoglycan
T
Porins are channels in cell membranes
T
Flagellae confer motility on bacteria
T
Pili enable bacteria to attach to target surfaces
T
Mycobacteria stain well with the gram stain
F
The Ziehl Neelsen (ZN) stain is for fungi
F
The auramine stain is a fluorescent stain
T
Gram negative intracellular diplococci are typical of Neisseria spp.
T
Campylobacter spp. are spiral gram negative bacteria
T
Dark ground illumination is used for very thin bacteria
T
Flagella help bacteria to adhere to surfaces
F
Fimbriae are used for motility
F
Capsules allow long term dormancy
F
Spores help the bacterium evade the immune system
F
True or false
Gram positive cocci in clusters are typical of a Staphylococcus spp.
T
Gram positive cocci in chains are typical of a Streptococcus spp.
T
Gram positive rods arranged as chinese characters are Bacillus spp.
F
Spores are formed by Clostridia spp.
T
Spores are formed by Bacillus spp.
T
Fungal cell walls contain cellulose
F
Fungi can perform photosynthesis
F
All fungi are filamentous
F
A mould is a yeast
F
Di-morphic fungi can exist as both yeasts and as filamentous fungi
T
True or false
Conidia become airborne and spread infection through the air
T
Fungi are not inhibited by antibiotics
T
Candidiasis is common in immunosuppressed patients
T
Aspergillus is a dimorphic fungus
F
Sabouraud’s medium is a common fungal media
T
True or false
Trematodes are flukes
T
Cestodes are tape worms
T
Nematodes are round worms
T
Helminths are parasites
T
Helminths have backbones
F
Ascaris is several mm long
F
Helminths are ‘neglected tropical diseases’
T
Diagnosis of helminth infection is often by microscopy
T
Helminths stay in the gut and don’t invade tissue
F
The global parasite burden is small
F
True or false
The ‘microbiome’ collectively refers to all organisms
T
The microbiome may influence the development of our immune system
T
Each person’s normal flora is constant and doesn’t change
F
‘Colonisation resistance’ resists the establishment of new flora
T
A ‘carrier’ of a pathogen is colonised with that pathogen
T
E. coli is part of the normal gut flora
T
S. aureus is carried by about 30% of people in the anterior nares
T
Commensals can cause infections
T
Candida is normal flora but causes disease when allowed to proliferate
T
Overgrowth of Clostridium difficile is harmless
F
Coagulase negative staphylococci don’t cause infections
F
Blood cultures are often contaminated with skin flora
T
Transient carriage is not an infection control problem
F
Cutibacteria contribute to acne
T
Normal skin flora includes mites and yeasts
T
The mouth is a clean site, devoid of normal flora
F
Bite wounds are treated with amoxicillin-clavulanic acid
T
Oral anaerobic bacteria contribute to bite wound infections
T
Pathogenic bacteria may be carried in the pharynx
T
Aspiration of oral flora can result in aspiration pneumonia
T
Organisms cultured from lung samples are always pathogens
F
When cilia function is compromised, infections follow
T
The stomach pH is too low for most bacteria to survive
T
Helicobacter pylori colonises the stomach
T
The small bowel has a rich flora
F
Oral flora is unaffected by antibiotics
F
Lung abscesses often contain mixed streptococci and anaerobes
T
E.coli is the main constituent of large bowel flora
F
Vaginal flora fluctuates with age and hormonal status
T
