* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Bacterial Infections
Staphylococcus aureus wikipedia , lookup
Horizontal gene transfer wikipedia , lookup
History of virology wikipedia , lookup
Traveler's diarrhea wikipedia , lookup
Gastroenteritis wikipedia , lookup
Infection control wikipedia , lookup
Quorum sensing wikipedia , lookup
Neonatal infection wikipedia , lookup
Phospholipid-derived fatty acids wikipedia , lookup
Microorganism wikipedia , lookup
Trimeric autotransporter adhesin wikipedia , lookup
Carbapenem-resistant enterobacteriaceae wikipedia , lookup
Anaerobic infection wikipedia , lookup
Hospital-acquired infection wikipedia , lookup
Disinfectant wikipedia , lookup
Human microbiota wikipedia , lookup
Triclocarban wikipedia , lookup
Marine microorganism wikipedia , lookup
Neisseria meningitidis wikipedia , lookup
Bacterial taxonomy wikipedia , lookup
Bacterial Infections HB6 2010 Bacteria are: Unicellular Small (1-4mm) Prokaryotes- no nucleus or membrane bound organelles Different metabolic reactions to us (peptidoglycan cell wall) Different sources of energy Photosynthetic bacteria Chemosynthetic bacteria Pathogenic bacteria are heterotrophs- get energy from other organisms Generalised bacterial cell Escherichia coli Bacterial shapes Bacterial naming Bacteria are usually referred to by their binomial name: Genus species e.g. Escherichia coli This may include Latin words referring to the shape, disease caused by the bacterium, or other properties Some examples: Helicobacter pylori Staphylococcus aureus Staphylococcus epidermis Streptococcus pneumoniae Vibrio cholerae Neisseria meningitidis Neisseria gonorrhoeae Mycobacterium tuberculosis Mycobacterium leprae Gram positive Thick cell wall containing mostly peptidoglycan Gram negative Cell wall contains less peptidoglycan & more lipid Aerobic Use oxygen for metabolism Anaerobic Don’t use oxygen for metabolism, oxygen may be highly toxic to them Bacterial reproduction Bacteria have a short generation time (as short as 20min) Bacteria reproduce binary fission: The DNA is replicated The cell elongates in the middle The cell wall & cell membrane pinch inwards Two cells separate Why are bacteria so successful? They reproduce quickly They evolve quickly (e.g. antibiotic resistance) They can live in extreme environments (e.g. in hot pools- 90oC) Some can form endospores, which can survive for many years (e.g. anthrax) Not all bacteria are bad! Lactobacillus- ferment milk to make yoghurt and cheese Bacteria are decomposers- break down dead organisms and sewage and recycle the nutrients There are millions of bacteria in our digestive systems- these produce vitamin K (needed for blood clotting) Bacteria as pathogens Some bacteria which gain their energy from other organisms can act as pathogens The negative effects on the host are generally either from toxins produced by the bacteria or from chemicals released by damaged cells Tetanus Wound infection by Clostridium tetani Produces a neurotoxin which causes a prolonged muscle contraction Death due to spasm of the breathing muscles About 10 cases each year in Australia, of which one will die Neonatal tetanus (often infection of the umbilical stump) has a death rate of approximately 75% Gram positive Obligate anaerobe Forms spores which can be found in soil Rod-shaped (‘tennis racket’) Some pathogenic cocci Streptococcus pyogenes Causes skin infections Chains of cocci Staphylococcus aureus Causes wound infections Groups of cocci Neisseria gonorrhoeae Causes gonorrhoea Diplococci (pairs) Neisseria meningitides Causes meningococcal disease Diplococci Some pathogenic spirilli Treponema pallidum Causes syphilis Spirochetes (long spiral shape) Bacterial pneumonia Anthrax forms spores which remain dormant in the ground until they are in hospitable surroundings. Some bacterial diseases Pneumonia Appendicitis Meningococcal disease Skin infections Food poisoning Some pathogenic bacilli Escherichia coli Normally found in human intestines & faeces Some strains cause severe food poisoning Haemophilus influenzae Causes some types of pneumonia