Microbiology Quiz - Cheat Sheet

1. What type of toxins Endotoxins are weakly antigenic ? 2. What type of toxin is cholera toxin? Enterotoxin produced by Vibrio Cholerae 3. How is Nosocomial in- - Hand washing fection controlled ? - Personal protective equipment (Barrier nursing) - Maintaining standards outlined in law (Health and social care acts) - Infection control teams are essential 4. What antibiotics tar- - Polymyxins get the stability of - Polyenes the Bacteria cell membrane ? 5. Antibiotics resistance Phosphorylation - Addition of a phosphate group - How is Streptomycin modified ? 6. Antibiotics resistance Acetylation - addition of acetyl group - How is Chloramphenicol modified ? 7. What is the pathogen Yersinia pestis that causes Bubonic plague ? 8. What is Bacteraemia? Transient appearance of organism in blood 9. What is Septicaemia ? Chronic high level growth in blood 10. What type of parasites Obligate parasites are viruses? 11. Name the subtypes of 1. Site-specific toxins - Cytolytic toxins , Enterotoxins, Exotoxins ? Neurotoxins 2. Multicomponent toxins - AB toxins 1/5 3. Superantigen - Necrotising toxins 12. Name the type of En- Lipid A dotoxin ? 13. How is Malaria trans- Bite of female Anopheles mosquito mitted? 14. How is the Plague transmitted to humans ? A rat flea (Xenopsylla cheopsis) from an infected rodent bites humans. 15. How does Yesinia pestis evade the phagocytosis process? - once it enters blood it secretes a virulence factor F1 protein - Forms a protective gel like capsule around the bacterium and helps it to escape phagocytosis. 16. How is Anthrax caused ? By inhaling the spores of Bacillus anthracis present in soil of pastures. 17. How is Anthrax char- - appearance of 'eschars' or 'malignant pustules' acterised ? 18. What is the cause of Leptospirosis? Spirochete Leptospira interrogans - infects mammals such as rats and dogs 19. What are the symptoms of Rabies ? Neurological symptoms: - Agitation - Hydrophobia - Hallucinations - Excessive salivation 20. What type of toxin is Enterotoxin B produced by staphylococcus aureus ? A neurotoxin - It affects the vagus nerve to induce the vomiting reflex. 21. It is a true enterotoxin - also an example of a A-B toxin 2/5 What type of exotoxin does Vibrio cholerae produce ? 22. Name the pathogen commonly seen in hospitals that causes Nosocomial infection ? Clostridium difficile - transmitted through faecal-oral transmission of the infectious agent. - it is a problem as its not susceptible to many usual frontline antibiotics e.g., metronidazole or vancomycin. 23. What are Exotoxins ? Microbial toxins secreted from the cell to cause effects: - soluble - heat labile - secondary metabolites produces during growth 24. What are Endotoxins ? Structural components of the cell wall that interacts with the immune system to cause severe diseases e.g.,: Lipopolysaccharide (LPS) - Lipid A - Gram - ve's Lipoteichoic acids - Gram + ves Zymozan - component of yeast membranes - mainly released on the death of the organism 25. What is the A part of A-B toxins ? toxic part 26. What organism uses A-B toxin to cause death to a variety of cell types ? Corynebacterium 27. What Neurotoxin Botulinum toxin = produced by Clostridium botublocks the release of linum and Clostridium tetani (they work at the Nerve excitatory inhibitors synapse) causing flaccid paralysis and respiratory collapse ? 3/5 28. What Neurotoxin Tetanus toxin (Tetanospasmin) blocks the release of inhibitory neurotransmitters resulting in continuous contraction of muscles = spastic paralysis ? 29. What type of mecha- Hydrolytic damage by steam nism does Moist heat use ? 30. What type of mechanism does Dry heat use ? Oxidative Processes 31. What is the size of a virus ? 10-100 nm 32. What is the size of a Bacterium ? 1 Micrometre 33. What is the size of a Animal cell ? 10 micrometre 34. What is the size of a Plant cell ? 100 micrometres 35. What is the function of Storage of carbon, phosphate, nitrogen & other subInclusion bodies ? stances. 36. What is Function of Endospores ? Survival in harsh conditions 37. What does periplasm Contains Various proteins: of Gram Negative Bac- - Enzymes with hydrolytic functions = Alkaline Phosteria contain ? phate - Antibiotics - inactivating enzymes = Beta-lactamases - proteins with roles in chemotaxis 4/5 - proteins with roles in active transport of solutes into the cell. 38. What type of Flagel- Peritrichous Flagella - All around the cell la does Salmonella enteritidis have ? 39. What are Primary metabolites ? A compound directly involved in normal growth, development, and reproduction e.g., Amino acids, Vitamins, Citric acid, Acetic acid, Ethanol. 40. What are Secondary metabolites ? A compound that is not directly involved in normal growth, development and reproduction. E.g., Antibiotics 5/5