Medical Microbiology Flashcards
What is the main difference between gram +ve and gram -ve bacteria?
Cell wall is thicker in gram +ve bacteria
What are the different bacterial shapes?
Cocci - sphere Bacilli - rod Coccobacillus - oval Vibrio - comma Spirilla - curved rod Spirochetes - corkscrew
What are the different bacterial arrangemetns?
Staphylo - grapes
Strepto - links
What does Staphylococcus aureus cause?
Wound infections, Food poisoning
What does Streptococcus pyogenes cause?
Nasopharyngeal infections, wound infections
What does Clostridium perfrigens cause?
Wound infections, food poisoning
What does Clostridium difficile cause?
Wound infections, food poisoning
What does Bacillus anthracis cause?
Anthrax
What does Nieserria meningitides cause?
Meningitis
What does Nieserrie gonorrhoeae cause?
Gonorrhoea, conjunctivitis
What does Escherichia coli cause?
Food poisoning, diarrhoeal or haemorrhagic gastroenteritis, wound infections
What does salmonella cause?
Food poisoning, enteric fever, gastroenteritis, bacteraemia
What does Shigella cause?
Dysentery
What does Haemophillus influenzae cause?
Meningitis, Respiratory tract infections
What does Yersinis pestis cause?
Respiratory tract infections, bubonic plague
What does Vibrio cholerae cause?
Cholera
What does Vibrio parahaemolyticus cause?
Food poisoning, wound infection
What does Chlamydia trachomatis cause?
Chlamydia
What does Mycoplasma cause?
Respiratory tract infections
What does Mycobacterium cause?
Tuberculosis, leprosy
What does streptococcus pneumoniae cause?
Pneumonia
What does Helicobacter pylori cause?
Abdominal pain, nausea
What does Treponema cause?
Syphilus
What does Propionibacterium cause?
Acne
What does methicillin resistant staphylococcus aureus cause?
Wound infections, Food poisoning
What does Trypanosoma cause?
Fever
What does Staph saprophyticus cause?
UTI
What does Staph epidermidis cause?
Red bumps on skin
What does Beta haemolytic Strep Group A cause?
Tonsilitis
What does Beta haemolytic Strep Group B cause?
Issues with breathing in babies
What does Viridans group Streptococci cause?
Fatigue, fever
What does Clostridium tetani cause?
Tetanus
What are obligate aerobes/anaerobes?
Bacteria which require either O2 or no O2 to respire
What are facultative anaerobes?
Grow with or without O2
What are microaerophilic bacterium?
grow with CO2 in reduced O2
What are the 4 serotypes?
Liposaccharides - O antigens
Flagella - H antigens
Capsule - K antigens
Fimbriae - F antigens
Human bacteria are optimal aat ~37C what are they called?
Mesophiles
What are the 5 virulent factors?
Colonisation Invasion Host damage Resistance to host defence Latency
How do bacteria colonise their hosts?
Adhesion - Surface charges, hydrophobicity, fimbriae, surface adhesion molecules
How do bacteria invade their hosts?
Alteration of the cytoskeleton
How do bacteria damage their host?
Endotoxins, Exotoxins
How do bacteria evade the host defence?
Capsules, Decoy proteins, encapulation in clot, cell death of macrophages, change of structure to avoid detection, change surface proteins to avoid antibodies
What is latency?
When the bacteria lies dormant in the host and becomes activated at a later stage. Usually when the host is immunosuppressed
What does microscopy culture and sensitivity (MC&S) do?
Grows colonies of a patient sample so as to identify the bacteria by outting those colonies under different conditions to see if they survive
What are the different haemolyses?
beta - complete degradation of RBCs
alpha - incomplete dgradation of RBCs
gamma - no degradation of RBCs
