Infections Flashcards
Name some of the classes of infectious agents???
- Bacteria
- Viruses
- Fungi (inc yeasts)
- Parasites
- Prions
Name an organism that is capable of living in any tissue?
Staph aureus (makes coagulase)
Name an organism that is capable of releasing products that damage widely??
Ecoli (produces endotoxins that spread via the blood streat)
True or false:
These organisms are capable of living and reproducing in many tissues:
Influenza virus, aspergillus, clostridium spp.
FALSE
These organisms live in very few condtions:
-influenza viruses bind to sialic (neuraminic) acid on respiratory mucosa
-Aspergillus spp sporulate only when in contact with air
-Clostridium spp require hypoxic conditions
True or false:
C.Diff and C.botulinum release toxins that can damage many tissues?
FALSE
- C,diff releases a chemical that harms the large intesting mucosa
- Clostridium botulinum releases a toxin ingested with food
What are ENOtoxins?
They are products of cells that have died. Produced by intact bacteria. Typically have specific effects.
What are ENDOtoxins?
and how does it damage tissue
- Components of bacterial cell walls
- Trigger compliment cascade
- Trigger coagulation cascade
- Induce interleukin 1(cause fever)
What is the name of the thing that is on the surface of bacterial cell walls that allow adhesion?
Pili
hair like projection- means hair in latin
Various types of bacteria release a certain chemical called ‘collagenaese’. What does collagenaese do?
It breaks down collagen and allows the bacteria to pass through bodily tissues.
Given an example of a immune cross- reaction…
EG
Streptococcal sore throat can lead to rheumatic fever. Because the antibodies react with cardiac muscle.
Name some ways in which Viruses can damage tissue…
- Direct cytopathic effect (influenza virus, hepatitis A)
- Immune reactions (hep B and C, T1DM (perhaps))
- Incorporation of viral genes into host genome (variety of oncogenic [cancer cells potential] viruses)
What is the yeast infection candida albicans associated with?
LOCAL (thrush):
- Oral/vaginal
- Poor hygene
- Bacterial/flora alterations (chemo, antibx, diabetes, steroids)
- Diabetes mellitus
SYSTEMIC:
-Immunosupressed
Name some parasites???
- Protozoa
- Trematodes (Flukes)
- Nematodes (roundworm)
- Castodes (Flatworm/ tapeworms)
What paracites cause these diseases:
- Amoebiasis (dissentry, liver abscess)
- Giardiasis (intestine infection, diarrhoea)
- Malaria
- Trichomoniasis (trichomonas vaginalis, venereal transmission)
These are all Protozoal diseases
What is the name of the paracite that lives in water all over the world (river nile) and gets into the body through skin.
SCHOSTOSOMIASIS (flukes/ Teratodes)
Life cycle involves human and water snails. Granulomata in urinary bladder (S Haematobium) or liver (Smansoni or japonicum)
Give some examples of the paracite ‘worms’ and the effects of them…
-Roundworms: enterobius vermicularis (threadworms) cause itchy bum. Can see in poo
-Tapeworms: Dipyllobothrium latum rare found in fish: risk with raw fish. Cause B12 deficiency
Echinococcus granulosus (dog tapeworms causing liver cycts)
What is the part of the body that is more commonly exposed to bacteria than any other organ
The lungs
What are some ways our body protects our lungs?
- Nasopharyngeal filtering (hair traps, nasal mucous)
- Mucocilary apparatus (mucus in bronchi, cilia on columnar cells)
- Coughing
- Resident alveolar macrophages
Name some factors that can interfere with our body’s defences of the lungs…
- Loss/suppression of cough reflex (anaesthetic, neuro’ disorders, drugs, chest pain, coma)
- Interference with cilia (smoking, hot gas, viral disease like flu, inherited bad cilia - dyskinesia)
- Change in mucous (dehidration, cystic fibrosis, chronic bronchitis)
- Poor alveolar macrophage function (work less well in cigarette smoke/ alcohol)
- Pulmonary oedema
- Bronchial obstruction
- Nosocomial infection
What are prions?
They’re infectious particles with no DNA or RNA.
- Transmissible somngiform encephalopathy
- Creutzfeldt-Jakob disease
- Exogenous protein causes conformational changes in endogenous protein
A patient comes in a+e with diarrhoea and weight loss. She has been on holiday in India and may have drank water that was contaminated with faecal matter . The doctor says she has a small intestine infection.
What is it?
Giardiasis (protozoa disease)
A patient is said to have colonisation of the colon causing amoebic dysentery and the Dr won’t give them anti-diorrhea medication as they say the infection must come out.
What is their infection?
Amoebiasis (Protozoal disease)
A patient went on holiday to Egypt and swam in the Nile. Since coming home they have been diagnosed with a granulomata in the bladder. What could have caused this?
Schistosomiasis (a disease caused by Flukes also called trematodes)
What’s another name for Trematodes?
Flukes
Mr X likes to eat sushi with raw fish in. He has recently been diagnosed with random B12 deficiency even though his diet should compensate. What could be causing this?
Diphyllobothrium latum (tapeworm)
Caused by raw fish and causes B12 deficiency
What parasite reproduces in the GI tract and sits on the bum causing itching. It is visible in faeces and can be treated with OTC medication ‘Pripsem’
Treadworms (Enterobius vermicularis)
What class of infectious agent is a particle with no DNA or RNA?
Prions (=proteins)
They are transmissible spongiform encephalopathy. Causes proteins in the body to change shape.
