1What bacterium causes strep throat?
Streptococcus pyogenes.
2What is the Gram reaction of Streptococcus pyogenes?
Gram-positive.
3How are Streptococcus pyogenes cells arranged?
In chains.
4How is strep throat transmitted?
Respiratory droplets.
5What are common symptoms of strep throat?
Fever, sore throat, swollen lymph nodes, and tonsil exudate.
6What does M protein help Streptococcus pyogenes do?
Adhere to host cells and evade immune defenses.
7What does streptokinase do?
Breaks down blood clots.
8What do streptolysins do?
Damage and destroy blood cells.
9What causes scarlet fever?
An erythrogenic toxin from Streptococcus pyogenes.
10How does Streptococcus pyogenes acquire the scarlet fever toxin gene?
Through a bacteriophage.
11What causes erysipelas?
Usually Streptococcus pyogenes.
12What tissue does erysipelas affect?
The dermis and upper skin layers.
13What does erysipelas look like?
Raised, red, inflamed skin patches.
14What is necrotizing fasciitis?
A rapidly spreading infection that destroys fascia and deeper tissues.
15How do bacteria commonly enter to cause necrotizing fasciitis?
Through wounds or breaks in the skin.
16How is necrotizing fasciitis treated?
Urgent antibiotics and surgical removal of dead tissue.
17What is pneumonia?
Inflammation of the lungs involving fluid in the alveoli.
18What is a major cause of bacterial pneumonia?
Streptococcus pneumoniae.
19What is the Gram reaction of Streptococcus pneumoniae?
Gram-positive.
20What does the pneumococcal capsule do?
Protects the bacterium from phagocytosis.
21What does pneumolysin do?
Damages host cell membranes and ciliated cells.
22What does IgA protease do?
Breaks down secretory IgA antibodies.
23What are common symptoms of pneumococcal pneumonia?
Fever, fatigue, and persistent cough.
24How can pneumococcal pneumonia be prevented?
Vaccination against capsule polysaccharides.
25Which bacterium can cause pneumonia and meningitis?
Haemophilus influenzae.
26What type of pneumonia can Mycoplasma pneumoniae cause?
Atypical pneumonia.
27Why do beta-lactam antibiotics not work against Mycoplasma?
It lacks a typical peptidoglycan cell wall.
28What is food intoxication?
Illness caused by toxin already present in food.
29What is food infection?
Illness caused by consuming living bacteria that grow in the body.
30What bacterium causes staphylococcal food intoxication?
Staphylococcus aureus.
31What causes symptoms in staphylococcal food intoxication?
Preformed enterotoxin in food.
32What are symptoms of staphylococcal food intoxication?
Nausea, vomiting, cramps, and diarrhea.
33Why can symptoms begin quickly after eating contaminated food?
The toxin is already present in the food.
34Why may reheating food not prevent staphylococcal food intoxication?
The enterotoxin is heat-resistant.
35Are antibiotics usually useful for staphylococcal food intoxication?
No; the illness is caused by preformed toxin.
36What bacterium causes cholera?
Vibrio cholerae.
37What is the shape and Gram reaction of Vibrio cholerae?
A curved Gram-negative rod.
38How is cholera transmitted?
Contaminated food or water.
39What is the characteristic stool of cholera?
Rice-water stool.
40What causes cholera's severe watery diarrhea?
Cholera toxin.
41What are the two parts of cholera toxin?
A and B subunits.
42What does the B subunit of cholera toxin do?
Binds to intestinal host cells.
43What does the A subunit of cholera toxin do?
Activates adenylate cyclase.
44What happens to cAMP during cholera?
Intracellular cAMP increases.
45What does increased cAMP cause?
Increased electrolyte secretion into the intestine.
46Why does cholera cause dehydration?
Water follows secreted electrolytes into the intestine.
47What is the priority treatment for cholera?
Rapid fluid and electrolyte replacement.
48What antibiotic was discussed for cholera?
Tetracycline.
49How can cholera be prevented?
Safe water, sanitation, and proper food handling.
50What bacterium causes peptic ulcer disease?
Helicobacter pylori.
51What is the shape and Gram reaction of Helicobacter pylori?
A curved Gram-negative rod.
52How does Helicobacter pylori move through stomach mucus?
Using flagella.
53What enzyme helps Helicobacter pylori survive stomach acid?
Urease.
54What does urease break down?
Urea into ammonia and carbon dioxide.
55How does ammonia help Helicobacter pylori?
It raises the local pH around the bacterium.
56How does Helicobacter pylori contribute to ulcers?
It damages the protective stomach lining.
57What test can detect Helicobacter pylori?
The urea breath test.
58What medications were discussed for Helicobacter pylori treatment?
Clarithromycin and omeprazole.
59Which bacterium commonly causes staphylococcal skin infections?
Staphylococcus aureus.
60What is folliculitis?
Infection or inflammation of hair follicles.
61What is impetigo?
A superficial skin infection with crusty lesions.
62What causes scalded-skin syndrome?
Staphylococcal exfoliative toxins.
63What does Protein A do?
Binds antibody Fc regions and interferes with phagocytosis.
64What does coagulase do?
Promotes blood clot formation.
65What does the Staphylococcus aureus capsule help prevent?
Phagocytosis.
66What does staphylococcal lipase help bacteria do?
Grow on skin.
67What does beta-lactamase do?
Breaks down beta-lactam antibiotics.
68What does toxic shock syndrome toxin do?
Acts as a superantigen and triggers severe inflammation.
69What can toxic shock syndrome cause?
Severe low blood pressure and shock.
70What bacterium causes gas gangrene?
Clostridium perfringens.
71What is the Gram reaction of Clostridium perfringens?
Gram-positive.
72What is the oxygen requirement of Clostridium perfringens?
Obligate anaerobe.
73What important structure does Clostridium perfringens form?
Spores.
74How does gas gangrene develop?
Spores enter deep wounds and grow in low-oxygen tissue.
75What causes tissue destruction in gas gangrene?
Bacterial toxins.
76What are symptoms of gas gangrene?
Severe pain, swelling, foul odor, and gas in tissue.
77What causes crepitation in gas gangrene?
Gas trapped in infected tissue.
78How is gas gangrene treated?
Antibiotics and surgical debridement; amputation may be needed.
79Why can hyperbaric oxygen help gas gangrene?
High oxygen levels inhibit the obligate anaerobe.
80What bacterium causes Rocky Mountain spotted fever?
Rickettsia rickettsii.
81Is Rickettsia rickettsii intracellular?
Yes; it lives and reproduces inside host cells.
82How is Rocky Mountain spotted fever transmitted?
By an infected Dermacentor tick.
83What are common symptoms of Rocky Mountain spotted fever?
Fever, muscle pain, malaise, and rash.
84Where does the Rocky Mountain spotted fever rash usually begin?
At the extremities and spreads inward.
85What causes tissue damage in Rocky Mountain spotted fever?
Infection and damage to blood vessels.
86What antibiotic group treats Rocky Mountain spotted fever?
Tetracyclines.
87What bacterium causes epidemic typhus?
Rickettsia prowazekii.
88How is epidemic typhus transmitted?
By infected body lice.
89Where does the typhus rash usually begin?
On the trunk and spreads outward.
90What test was discussed for rickettsial diseases?
The Weil-Felix test.
91What does the Weil-Felix test detect?
Cross-reacting antibodies that agglutinate Proteus OX19.
92What antibiotic group treats typhus?
Tetracyclines.