Role of microbes and microbe caused disease Flashcards
Symptoms of HIV infections
- Stage 1: First few weeks, flu symptoms in 50% of cases. Viral load high, immune cell level increases
- Stage 2: Months to years, clinical latency. Viral load lower, immune cell level declines
- Stage 3: Symptomatic HIV infection. Viral load higher, immune cells lower. Opportunistic infections occur.
- Stage 4: AIDS. Viral load high, immune cells low. Opportunistic infections, severe illness.
An insecticide used to kill mosquitoes, now banned for agricultural use, but still used cautiously in South Africa to limit malaria
DDT
Prophylactic medication
Medication taken to prevent getting a disease
Treatment of thrush
- Oral antiseptics
- Anti-fungal creams
- In severe cases - anti-fungal tablets
Management of plant diseases
Exclusion:
- Disease free stock used to cultivate
- Proper soil management e.g. not over watering
Eradication:
- Cultivate plants that the disease cannot feed on
- Burn affected plant waste
- Spray with fungicides
Resistant crops:
- Specific varieties that are not affected by disease as easily
Prevention of TB
- BCG vaccine mostly effective
- Treating those who can spread the disease
TB
Tuberculosis Species:
Mycobacterium tuberculosis
- Rod shaped bacterium
- Major cause of death worldwide
Prevention of malaria
- Avoid mosquito bites in malaria areas:
- Long sleaves
- Insect repellants
- Bed nets
- Netting over windows
- Remove standing water from around house
- Anti-malarial drugs taken when entering malaria areas
Treatment of HIV
- Initially, promote healthy lifestyle (diet, stress and exercise)
- assess immune levels by measuring CD4 cell count
- Antiretrovirals or ARV’s when CD4 count drops
- medicine to prevent and treat opportunistic diseases e.g. Antibiotics
Role of fungi in the environment
Decomposers:
- Break down complex organic compounds
- Release nutrients
Mycorrhiza:
- Mutualistic relationship in roots of plants
- provide minerals for plants
Notifiable diseases
- In humans, have to be reported to Department of Health
- In animals, have to be reported to state veterinarian
Decomposition
- Break down complex organic compounds
- Release nutrients
Cycle of infectious diseases
- Pathogen infected host
- Portal of exit
- Mode of transmission
- Portal of entry and susceptibility
- Incubation
- Period of communicability
Prevent mosquito bites
- Mosquito nets
- Insecticide treated nets
- Mosquito repellants
Nitrogen fixation
- Plants need nitrogen to make amino acids
- Atmospheric nitrogen cannot be used to do this
- Soil bacteria convert nitrogen into nitrates
- Bacteria in plant roots convert nitrogen into amino acids
- Nitrifying bacteria convert ammonia into nitrates
Effects of HIV infection
- T4 lymphocytes (helper cells) destroyed
- T4 cells don’t bring killer cells to fight infection
- bodies immune system breaks down
- opportunistic infections
Treatment of malaria
- Oral medicines killing the parasite
- First effective drug: Quinine
- Nowadays: Artemisinin use in combination with other drugs
- In severe cases intravenous medicines.
- Both Quinine and Artemisinin are derived from plants
Symbiotic relationship in which both organisms benefit
Mutualism
Prevention of thrush
- Improved hygine (preventing parts of the body from being too warm and moist)
- Probiotics (eating healthy bacteria e.g. yoghurt and fermented foods)
- Balanced diet (cut out refined carbs and sugar!)
- Reduce stress (improve immune system function)
Mutualistic bacteria
- Synthesize some vitamins not easily available to host
- E.g. E. coli in human digestive tract vitamin E, K and some B’s
- E.g. Bacteria in ruminants (like cows)
Potato blight
- Fungus infecting potato crops
- Destroys much of the crop and has in the past caused famine in Europe
- Thrives in damp fields
Symptoms of TB
- Lung TB: Inflammation and lesions destroy lung tissue
- Tiredness, coughing, blood in sputum, chest pains, fever, sweating, poor appetite and weight loss
- TB lesions: Can occur in any part of the body e.g. bone and brain.
Malaria
Caused by a protist
Species: Plasmodium sp.
Vector of malaria
Female Anopheles mosquito
Role of bacteria in the environment
- Decomposers
- Nitrogen cycling
- Mutualism
XDR-TB
- Extensively drug resistant TB
- Second-line drugs used to treat MDR-TB no longer work for these strains
Mode of transmission of TB
Especially those with active TB infections spread TB bacteria by coughing and sneezing.
Infection with HIV eventually leads to… (Full name)
Acquired immune deficiency syndrome (AIDS)
Symptoms of malaria
Flu-like Fever and muscle aches
Sweating
Fatige
Plasmodium falciparum can cause cerebral (brain) infections leading to death within days
Symptoms of thrush (effects)
- Affects: mouth, vagina, skin
- Fluffy white patches
- Red, inflamed areas under the patches
- Severe irritation
Cells infected by HIV
T4 lymphocytes (helper cells)
Thrush (causes)
- Fungal infection called candidiasis
- Species: Candida albicans
- Affects mainly moist parts of body
Symbiotic relationships
Mutualism
Symbiotic relationship where one organism benefits and the other is harmed
Parasitism
Symbiotic relationship where one organism benefits and the other is not affected
Commensalism
Role of algae in the environment
Photosynthesis:
- major source of food in aquatic ecosystems
- provide much of the atmospheres oxygen
Treatment of TB
- Antibiotics
- Managed by DOTS
- Directly Observed Treatment, Short-course
- at least 6 months of medicines
- Side effects: Nausea, liver damage, skin rashes
Modes of transmission of HIV include:
- Sexual intercourse (all kinds)
- Non-sterile needles
- Across placenta and during birth
- Contact between wounds or mucous membranes with infected body fluids
HIV is… (full name)
Human immunodeficiency virus
Antibiotics
- Typically used to kill bacteria
- antibacterial chemicals made by certain fungi
- Term often also includes drugs against protists and fungi (antifungals)
Infectious diseases that are transmitted
Contagious or communicable diseases are passed from one host to another
Opportunistic infections
Infections caused by pathogens that don’t affect a person with a healthy immune system
Drugs that treat microbes
Antimicrobial drugs:
- anti-viral drugs
- antibiotics
- anti-fungal drugs
Two ways of treating bacterial infections
- Bactericidal antibiotic doses - kill bacteria
- Bacteriostatic antibiotic doses - slow or stop bacterial growth
MDR-TB
- Multi-drug resistant TB
- If TB drugs misused, TB becomes resistant to treatment
- Takes longer to treat
- More expensive to treat
- More side effects to treatment
Steps of HIV replication
- HIV attaches to human cell
- RNA and enzymes enter cell
- RNA converted to DNA
- Cells resources used to make more viral proteins and RNA
- Parts assemble into new virus particles
- Particles released to infect more cells
Prevention of HIV
- sexual behavior e.g. abstinence, barriers
- avoiding infected blood e.g. gloves, transfusions
- ARV’s in pregnancy for those infected
- not abusing drugs and alcohol (lessen high risk behaviour)
Life cycle of malaria
- Mosquito feeds on malaria infected person
- Gametes of malaria enter mosquito
- Zygote formed in mosquito digestive tract
- Parasite develops and moves to salivary gland of mosquito
- Parasite injected into blood of person mosquito is feeding on
- Parasite enters liver cells and multiply
- Parasite leaves liver and enters red blood cells where they mature and divide
- Red blood cells burst and mosquito sucks them up…
Effects of various diseases on the economy
- Consider ages (children vs breadwinners vs older people)
- Consider the loss of labour and less workers in the economy
- Consider the loss of income for those affected
- Consider direct costs of treatment e.g. doctors and medication
- Consider if the disease is linked to poverty
