MICR 121 Lecture Notes - Lecture 7: Human Microbiota, Enterobacteriaceae, Only Time

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orchidwallaby340

9 Nov 2016

School

Queen's University

Department

Microbiology and Immunology

Course

MICR 121

Professor

Lewis Linton Tomalty

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Document Summary

Group a s tre ptococcus (s . pyoge ne s ) Le s ions a round mouth/nos e (hone ycomb s ha pe d a nd coloure d) Antibiotic the ra py without culture unle s s non-he a ling complica te d ca s e. S ome time s the re is both group a s tre p a nd. P e nicillin is the drug of choice but doe s not work a ga ins t group a. S e e it mos t ofte n in childre n pa re nts pick up from kids. Ca n ge t a n a s ymptoma tic s tre p throa t from it. P e ople colonize d with s . a ure us us ua lly in the nos e this is why it ca us e s the s e s kin infe ctions. Looks gros s , not ove rly s e rious.

Related Questions

30. Microbe-Human Interactions.

a. Define pathogen, disease, normal flora. Under what conditions might a normal flora organism cause disease.

b. What parts of the body should stay absolutely sterile under normal circumstances.

c. How are Kochâs postulates used.

d. Define communicable, non-communicable, acute, chronic, endemic, epidemic, pandemic,

symptomatic, asymptomatic, and subclinical.

e. For a disease to be spread, there must be a reservoir, mode of transmission, and portal of entry.

f. For humans, what is the most significant reservoir.

g. Define : direct contact, droplet transmission, indirect contact, vehicle transmission, arthropod vectors

h. For a microorganism to cause disease, it typically must attach to host tissue, overcome the host defense, and cause tissue damage.What structures are used for attachment.What are some ways in which microorganisms overcome the host immune system.What distinguishes exotoxins from endotoxin.

31. Immune Defenses.

a. What are the major elements of the first, second, and third lines of defense.

b. What are the steps of phagocytosis and inflammation? What are the 3 complement pathways?

c. Which lines of defense are considered specific? Which are considered non-specific?

d. There are two major types of specific immunity, humoral and cell-mediated.

e. Humoral immunity involves B cells and antibodies. What are the major classes and activities of antibodies.

f. Cell mediated immunity involves T cells. What are 2 major types of T cells? What are their activities.

32. Staphylococcus aureus.

a. Gram positive cocci in grape-like clusters.

b. Skin infections (scalded skin syndrome, impetigo) (many other types of infection are also possible).

33. Streptococcus pyogenes.

a. Gram positive cocci in chains.

a. Strep throat, skin/wound infections (impetigo, necrotizing fasciitis âflesh eating diseaseâ), scarlet fever (other types of infection are also possible)

burgundymallard431

1) What clinical manifestation do Staphylococcus aureus and Staphylococcus epidermidis share? A) nosocomial infections B) protein A antiphagocytic factor C) hyaluronidase enzyme D) enterotoxins E) staphylokinase 2) Which of the following has been historically classified as Gram-negative bacteria but is genetically more similar to low G + C Gram-positive bacteria? A) mycoplasmas B) Mycobacterium C) Clostridium D) Propionibacterium E) Nocardia 3) What is one virulence factor that differentiates Staphylococcus aureus from other species of staphylococci? A) It has a capsule. B) It can produce coagulase. C) It produces catalase. D) It can live on the surface of the skin and in cutaneous oil glands. E) It produces lipase. 4) Over 90% of Staphylococcus aureus isolates are penicillin-resistant. Why? A) They have loosely organized polysaccharide slime layers. B) They produce coagulase. C) Cell division occurs in successively different planes, and the daughter cells remain attached to one another. D) They produce Î²-lactamase. E) They produce staphylokinase, which dissolves fibrin threads in blood clots. 5) A woman comes to the emergency department with fever and vomiting. She soon develops a red rash all over her body, and her blood pressure begins to drop. What is one possible diagnosis? A) erysipelas C) scarlet fever B) endocarditis D) toxic shock syndrome E) staphylococcal food poisoning 6) Bacteria collected from a severely inflamed wound are sent to the lab for analysis. The results come back as follows: Gram-positive cocci in irregular clusters, kinase and coagulase positive, and able to grow in the presence of most antibiotics except vancomycin. The bacteria in the wound are most likely _______ A) Enterococcus. C) Staphylococcus aureus. B) Staphylococcus epidermidis. D) methicillin-resistant Staphylococcus aureus (MRSA). E) Streptococcus pyogenes (group A streptococcus). 7) Which of the following statements about "flesh-eating" streptococci is FALSE? A) It is caused by a group A streptococcus. B) It is also known as necrotizing fasciitis because it travels along the fascia. C) It causes death in over 50% of cases. D) It is considered a common complication of pyoderma. E) It involves toxemia. 8) Streptococcus agalactiae is associated with which of the following diseases? A) neonatal bacteremia B) neonatal meningitis C) neonatal pneumonia D) both neonatal bacteremia and neonatal meningitis E) neonatal bacteremia, neonatal meningitis, and neonatal pneumonia 9) What differentiates virulent strains of Streptococcus pneumoniae from nonvirulent strains? A) the species-specific teichoic acid present in its cell wall B) the type of Lancefield antigen it produces C) the presence of a polysaccharide capsule that protects it from digestion after endocytosis D) the type of toxins it produces E) the extent of the hemolytic zone it produces when it is grown on blood agar 10) Otitis media may lead to dangerous meningitis in children due to infection with _____ A) Streptococcus agalactiae. B) Streptococcus pneumoniae. C) Streptococcus mutans. D) Enterococcus. E) Mycoplasma pneumoniae. 11) Which of the following streptococci is associated with dental caries? A) viridans streptococci B) Streptococcus pyogenes C) Streptococcus pneumoniae D) Streptococcus equisimilis E) Streptococcus arginosus 12) Anthrax, which means "charcoal" in Greek, derives its name from _____ A) the airborne endospores it produces. B) the staining properties of the bacillus under the microscope. C) the black eschars it produces on human skin. D) its ability to invade the bloodstream and produce toxemia. E) the high mortality it causes in infected individuals. 13) Which of the following bacteria produce one of the most deadly bacterial toxins known? A) Clostridium perfringens C) Clostridium tetani B) Clostridium difficile D) Clostridium botulinum E) Corynebacterium species 14) Which of the following bacteria can cause life-threatening pseudomembranous colitis? A) Clostridium difficile B) Staphylococcus aureus C) Streptococcus pyogenes D) Enterococcus species E) Clostridium botulinum 15) How does the toxin from Clostridium tetani produce its action? A) It fuses irreversibly to neuronal cytoplasmic membranes, blocking release of acetylcholine at synaptic clefts. B) The smaller polypeptide of its toxin can block the release of inhibitory neurotransmitters by inhibitory neurons in the central nervous system, causing simultaneous contraction of both muscles in an antagonistic pair. C) It is a pyrogenic toxin, which triggers a diffused rash and, later, sloughing of skin. D) It destroys tissues, including muscle and fat. E) It produces antibodies that attack the neuromuscular junctions in skeletal muscle and prevent them from relaxing. 16) Listeria virulence is directly related to its ability to ______ A) produce powerful toxins. B) form very resistant endospores. C) live within cells and thus avoid exposure to the immune system of its host. D) easily become a pathogen in humans. E) resist most antimicrobial agents. 17) The pus from an abscess in a patient's jaw contains microbes that form yellowish grainy masses and appear filamentous under the microscope. Neither antifungal medication nor a normal course of antibiotics has been effective in treating the infection. The abscess is likely the result of infection with A) Actinomyces. B) Mycobacterium. C) Nocardia. D) Propionibacterium. E) Streptococcus. 18) What is the most common disease caused by Propionibacterium? A) acne B) food poisoning C) pneumonitis D) folliculitis 19) Streptococcus pneumoniae is a leading cause of ______ A) acne. C) pharyngitis B) furuncles. D) primary atypical pneumonia. E) otitis media. 20) The soil bacterium Nocardia asteroides can establish opportunistic infections of the _____ A) skin C) central nervous system B) lungs D) cardiovascular system. E) skin, lungs, and central nervous system

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MICR 121 Lecture Notes - Lecture 7: Human Microbiota, Enterobacteriaceae, Only Time

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