Infectious Agents Flashcards
Four main types of infectious agents
Bacteria
Fungi
Parasite
Virus
Bacteria [characteristics]
Capable of undertaking all metabolic processes Prokaryote: - no nucleus - no membrane bound organelles - unicellular
Flagella
Divides by binary fission
Eubacteria - mist are medically important so grown to identify conditions they grow best.
aar can manipulate and review their biochemical reactions
Bacteria stages of growth
Liquid medium - grow + become turbid
Solid medium - form colonies
Infections caused by bacteria
UTIs Skin infections - hot tub’ folliculitis caused by Pseudomonas aeruginosa Pneumonia Sepsis STIs Food poisoning
Common characteristic between all bacteria
Development of antibiotic resistance
Parasites [characteristics]
Metabolically dependent on another organisms for one or more stages of their life cycle
Eukaryote:
Has a variety of reproductive cycles - sexual and asexual
- means they have a variety of hosts
definitive (final stages) – where parasites undergo sexual reproduction
immediate (part of the life cycle) – where parasites undergo asexual repr.
Parasitic infection cause and form of infection
Parasitic infection - interaction via vector (usually mosquito/tick)
e.g,
Malaria – plasmodium spp. – transmitted by arthropod vector
Form of infection:
- free flowing
- encapsulated within human cells
Fungi [characteristics]
Eukaryote
Two forms:
1. Yeast - stays as yeast and forms colonies
2. Moulds - produces hyphae and have spores
Infections fungi cause
Superficial
e.g, athletes foot - tines pedis
Subcutaneous (cause infection w/in your skin – through graze/cut)
e.g, Sporotrichosis – sporothrix schenckii
Systemic (internal)
e.g. candidiasis - candida albicans
Viruses [characteristics]
Nucleic acid
enzymes
minimal info - can’t reproduce - needs a host
causes many infectious diseases
Example of infectious disease a virus causes
- Zika virus
Vector transmission – mosquito
Spread by daytime-active Aedes mosquitoes, such as A. aegypti and A. albopictus
