Lecture 1 Flashcards
polymicrobial
mixed organisms infecting an area
How do bats explain disease transmission?
tree roosting bats see different bats every night, urban bats sleep in same hole every night, seeing same bats.
Disease transmission is higher in Urban bats populations
infectious dose
number of infectious organisms or particles needed to cause an infection
what alters infectious dose?
it changes between individuals and diseases d/t differences in immune response and virulence
How is ebola transmitted?
blood to blood contact.
- can not be through mosquitos as they eat the blood but do not put it back inside
- needles hold blood inside them and then reinfect it into blood. so this could cause infection
- could be a nosocomial infection because requires contact
Necrotizing fasciitis
- staph aureus causing “flesh eating disease”
- usually polymicrobial (bacteria doesn’t cause tissue damage, immune response does)
How do microbes affect the earth
equal over 50% of carbon on earth
- 90% of nitrogen and phosphate is produced by bacteria
- contribute O2, recycle nutrients like N2
enrichment culture
the use of selective growth media that support certain classes of microbial metabolism while excluding others
Why are microbes beneficial?
- make vitamins (B12)
- enzyme functions d/t bacteria
- breath sulphur, fix nitrogen
- diverse and abundant
- live in many extreme environments
where are microbes located in body
everywhere, diverse populations grow in different areas of the body d/t different levels of sweat, salt, sun, nutrients
- “normal flora” - live in body and aide human with everyday processes (if too little or too many cn cause issues), may only be helpful in certain environments
- contais 10 times as many microbes as cells
how are microbes bad?
small portion of microbes are bad (causative agent of disease)
-principle cause of mortality
how are antibiotics bad, was is the post antibiotic era
- becoming less useful d/t antibiotic resistant pathogens
- an end to modern medicine – pathogens may become leading cause of death once gain
MRSA
Methicillin Resistance Staphylococcus aureus
- bacteria is normal habitant of skin, nose, resp and GI tracts.
- can causes skin/soft tissue/ bone infections, pneumonia, sepsis
- MR means first line treatments oil, second are less effective and have more side effects; need IV not pill forms
- in SASK 8% of SA is MR
how many antibiotic resistant infections were there in 2013?
how many in canada, how many deaths?
23000
-18000 in canada and 2000 deaths
how many people die annually from C. Diff? what is this?
15000
-infection of the bowel linked to long term antibiotic abuse
golden age of microbiology
19th century; principles of disease pathology and microbial ecology were established
autoclaving
physical method of controlling microbial growth by applying pressure to water to create steam (sterilizing materials like surgical instruments)
Robert Hooke
1665
First microscopist to publish a systematic study of the world as seen under a microscope
Built the first compound microscope and observed biological materials
Published his findings in Micrographia (looked at nematodes, mites and mold filaments)
First to observe distinct units of living material (termed “cells” to describe cork)
Antonie van Leeuwenhoek
1680
First individual to observe single-celled microbes (such as bacteria)
Single-lens magnifier (stronger than Hooke’s)
Observed insects (lice and fleas), large single cells (protists and algae), and bacteria (from mouth)
-Detailed observations about the shape and size of the species
-Observed microbes in his mouth before and after drinking hot coffee (suggested that heat kills microbes)
Louis Pasteur
- believed in biogenesis; not spontaneous generation
- discovered pasteurization –> heat liquid to 55 degrees destroying bad bacteria and preserving food
- Germ theory of disease