chapter 19
Lancefield classification
- divided into serotypes based on bacteria's antigens - groups A and B include significant human pathogens -Streptococcus
Streptococcus pyogenes virulence factors
-Surface antigens of S. pyogenes mimic host proteins -Surface antigens protect the organism from being affected by lysozyme -Streptolysin O and streptolysin S: injure cells and tissues -Some streptococcal toxins act as superantigens
systemic diseases of Staphylococcus
-Toxic shock syndrome -bacteremia -endocaditis -pneumonia -osteomyelitis
scarlett fever
-can occur following streptococcal phayrngitis infections -chest rash develops that spreads across the body- sloughing of skin
Clostriudium perfringens
-causes food poisoning -causes gas gangrene
Cord factor in TB
-cell wall component produced by virulent strains of M. tuberculosis -inhibits phagocyte migration and is toxic to mammalian cells
epidemiology of S. agalactiae
-colonizes the GI, genital, and urinary tracts -disease occurs w wound infections and childbirth causes most adult infections -newborns often inoculated at birth
How to prevent anthrax
-control of disease in animals -effective vaccines available -requires multiple doses and boosters
treatment of enterococcus
-difficult to treat -often resistant to antimicrobials
cutaneous diseases of Staphylococcus
-due to exotoxins -various skin conditions: scalded skin syndrome, impetigo, folliculitis
Clostridium tetani
-endospores are ubiquitous in soil, dust, and GI tract of animals and humans, enter anaerobic environment, germinate, grow and produce potent neurotoxin -continuous muscle conditions
Diagnosis of S. pneumoniae
-gram stain of sputum smears -confirmed w quellung reaction
how are group B strep distinguished from group A
-group specific cell wall antigens -smaller zone of beta hemolysis -resistant to bacitracin
how to prevent tuberculosis
-immunization where TB is common but not in the US -efficacy of the vaccine is not clear
Pharyngitis
-inflammation of the pharynx -accompanied by fever, malaise, and headache -"strep throat"
S. agalactiae pathogenicity
-often infects newborns w out specific antibodies -produces enzymes whose roles are not yet understood
pathogenicity of Streptococcus pneumoniae
-polysaccharide capsule prevents digestion after endocytosis -phosphorylcholine: stimulates cells to phagocytize the bacteria to hide inside the cells -protein adhesion: a protein that mediates binding of cells to epithelial cells of pharynx -secretes enzymes and proteins that counteracts w immune system
prevention of enterococcus
-prevention is difficult in health care setting -patients often have weakend immune systms -good hygeine and aseptic techniques minimize transmissions
Group A beta hemolytic Streptococcus: Streptococcus pyogenes Pathogenicity:
-produces enzymes and toxins -streptokinase -hyaluronidase -streptolysins
disseminated tuberculosis
-results when infection spreads throughout the body -symptoms arise due to complications at the various sites
Diagnosis of S. pyogenes
-skin infections diagnosed by the presence of gram positive bacteria in short chains or pairs -rapid strep test used to diagnose resp infections -streptococci in pharynx are not diagnostic
how to diagnose tuberculosis
-skin test identifies possible exposure -chest x-rays identify individuals w active disease
pathogencity of Staphylococcus results from what 3 factors
-structures that enable it to evade phagocytosis -production of enzymes -production of toxins
What is gas gangrene?
-trauma introduced endospores into body -endospores germinate and produce toxins that cause necrosis -removal of dead tissue, administer antitoxin and penicillin
tb kills how many people annually
2 million
What percent of patients are estimated to die from the disease? (Necrotizing Fasciitis)
20%
It is estimated that _____ of the world's population may be infected with tuberculosis. 1% 75% 5% 33%
33%
Based on its Gram status, why are penicillin and other beta-lactam antibiotics effective against Streptococcus pneumoniae? A.) Beta lactam antibiotics are effective against Streptococcus pneumoniae because it is a Gram positive organism and does not have an outer membrane. B.) Beta lactam antibiotics are effective against Streptococcus pneumoniae because it is a Gram negative organism and does not have an outer membrane. C.) Beta lactam antibiotics are effective against Streptococcus pneumoniae because it is a Gram positive organism and has an outer membrane. D.) Beta lactam antibiotics are effective against Streptococcus pneumoniae because it is a Gram negative organism and has an outer membrane.
A
Lance's physician administered a tuberculin test to determine whether Lance had been infected during his flight from South Africa. How was this test performed? A.) A small amount of cell wall material from Mycobacterium tuberculosis was injected into Lance's forearm skin. B.) Lance's blood was drawn and examined for the presence of Mycobacterium tuberculosis. C.) An X-ray film of Lance's lungs was taken. D.) A sputum specimen from Lance was cultured for possible growth of Mycobacterium tuberculosis.
A
S. pyogenes is what group
A
Streptococcus pneumoniae is found as part of the normal microbiota of the mouth and pharynx and yet can cause disease in some people when it is inhaled into lungs. Why do you think this is? A.) If Streptococcus pneumoniae is inhaled from the nasopharynx into lungs damaged by a previous viral infection or in an immune compromised person, it can flourish. B.) The environment in the lungs is more favorable for Streptococcus pneumoniae than the nasopharynx. C.) If Streptococcus pneumoniae is inhaled deeply enough into the lungs, there are receptors present to which the bacteria can adhere. D.) There is less immune system surveillance in the lungs compared to the nasopharynx.
A
The pneumococcal vaccine was made using the purified capsular material from 23 common strains of Streptococcus pneumoniae, but it is not effective against all strains. Why is this? A.) It cannot cover all the strains of Streptococcus pneumoniae because not all strains have the same antigens on their surface. B.) If a person is infected with a strain other than the 23 used to make the vaccine, it may not be recognized by neutrophils. C.) If a person is infected with a strain other than the 23 used to make the vaccine, it may not be recognized by the natural killer (NK) cells of the immune system. D.) It cannot cover all the strains of Streptococcus pneumoniae because not all strains have the same type of cell wall.
A
Lancefield groups __ and __ include the significant human pathogens
A and B
fungus shaped high G+C bacterium
Actinmyocetes Nocardia
Why are antimicrobial drugs of limited usefulness in Bacillus anthracis infections? B. anthracis grows so slowly that it is hard to kill using antimicrobial drugs. Anthrax toxin is absorbed into the bloodstream very quickly. Most strains of B. anthracis are resistant to a wide variety of antimicrobial drugs. Antimicrobial drugs are unable to neutralize anthrax toxin.
Antimicrobial drugs are unable to neutralize anthrax toxin.
S. agalactia is what group
B
Which of the following lists the criteria for a diagnosis of Staphylococcus aureus infection? A.)Staphylococcus aureus cultures are coagulase negative, catalase positive, white colonies that are composed of Gram-positive cocci. B.)Staphylococcus aureus cultures are coagulase positive, catalase positive, yellow colonies that are composed of Gram-positive cocci. C.)Staphylococcus aureus cultures are coagulase positive, catalase negative, translucent colonies that are composed of Gram-positive cocci. D.)Staphylococcus aureus cultures are coagulase positive, catalase positive, yellow colonies that are composed of Gram-positive bacilli.
B
What is the name of the vaccine given to prevent TB in countries where it is endemic? DTaP vaccine BCG vaccine RTS vaccine Pneumovax vaccine
BCG vaccine
large, nonmotile, gram-positive bacilli in lung or skin samples -what does this describe
Bacillus
rod shaped low G+C bacteria
Bacillus Clostridium Listeria Mycoplasma
Strains of Streptococcus pneumoniae can cause disease only when a capsule is present. Why is the presence of a capsule considered a virulence factor? A.) Streptococcus pneumoniae cannot adhere to the cells of the host without a capsule. B.) Streptococcus pneumoniae cannot migrate from the nasopharynx to other areas of the body without a capsule. C.) The capsule prevents the bacterium from being digested after endocytosis in the cells of the host. D.) The capsule prevents the bacterium from releasing chemicals that announce its presence to the host's immune system.
C
The BCG vaccine is available to immunize people against tuberculosis. Had Lance been vaccinated, he would not have been concerned about becoming infected on the airplane. Why was he NOT vaccinated? A.) The vaccine provides immune protection only for a low percentage of people. B.) The vaccine requires repeated booster shots because the immune protection is short lived. C.) Immunized patients have a positive skin reaction when tested, even if they have not been infected with Mycobacterium tuberculosis. Such "false positive results" hinder the work of epidemiologists trying to track the spread of the disease. D.)Use of the vaccine in large populations results in the emergence of drug-resistant strains of Mycobacterium tuberculosis.
C
toxins bind to neurons irreversibly and prevent muscle contractions
C. botulinum
what prevents muscle contractions
C. botulinum
pseudomembrane colitis, caused by toxins is associated with?
C. diff
what is a member of the intestinal flora, and is an opportunistic pathogen
C. diff
what causes constant muscle contractions
C. tetani
botulism
Clostridium botulinum
what is one of the deadliest foodborne toxin
Clostridium botulinum
Which of the following bacteria can cause life-threatening pseudomembranous colitis? Enterococcus species Streptococcus pyogenes Clostridium botulinum Staphylococcus aureus Clostridium difficile
Clostridium difficile
gas gangrene
Clostridium perfringens
What causes diphtheria?
Corynebacterium diphtheriae
Based on its Gram status, why are penicillin and other beta-lactam antibiotics effective against Streptococcus pneumoniae? A.) Beta lactam antibiotics are effective against Streptococcus pneumoniae because it is a Gram negative organism and does not have an outer membrane. B.) Beta lactam antibiotics are effective against Streptococcus pneumoniae because it is a Gram negative organism and has an outer membrane. C.) Beta lactam antibiotics are effective against Streptococcus pneumoniae because it is a Gram positive organism and has an outer membrane. D.) Beta lactam antibiotics are effective against Streptococcus pneumoniae because it is a Gram positive organism and does not have an outer membrane.
D
Streptococcus pneumoniae was originally named Diplococcus pneumoniae. Why was the genus name Diplococcus originally given to this organism? A.) The prefix "di- "means two and on agar plates, the colonies are found in groups of two. B.) The prefix "di-" means four, and these organisms are usually found in groups of four under the microscope. C.) The prefix "di- "means four, and on agar plates, the colonies are found in groups of four. D.) The prefix "di-" means two, and these organisms are usually found in pairs under the microscope.
D
2 species of Enterococcus that cause disease in humans
E. faecalis E. faecium
During a stay in the hospital, an accident victim develops symptoms of bacteremia. A blood sample shows the presence of Gram-positive cocci in pairs. Lab tests determine that the bacteria are nonhemolytic and bile salt tolerant. The bacteremia is likely due to Mycoplasma. Staphylococcus. Enterococcus. Streptococcus.
Enterococcus
listerosis
Found on deli/ready to eat meats
Propionibacterium belongs to what group
High G+C bacteria -rod
Streptococcus are often categorized by
Lancefiled classification
__________ is an antiphagocytic factor and helps S. pyogenes attach to nose and throat cells. M protein Deoxyribonuclease Hyaluronidase Streptolysin
M protein
what grows inside macrophages
M. tuberculosis
Vancomycin is used to treat
MRSA
MRSA is resistant to
Methicillin
Leprosy is caused by
Mycobacterium leprae
Where is mycolic acid found?
Mycobacterium species
Fried egg appearance on culture
Mycoplasma pneumoniae
What causes walking pneumonia?
Mycoplasma pneumoniae
Secondary or reactivated tuberculosis
Reestablishment of active infection after period of dormancy
B-lactamase
Resistance to penicillins
Primary Tuberculosis
Results from the initial infection with M. tuberculosis
-colonizes the GI, genital, and urinary tracts -disease occurs w wound infections and childbirth causes most adult infections -newborns often inoculated at birth
S. agalactiae
resistant to bacitracin
S. agalactiae
what causes neonatal bacteremia, meningitis, and pneumonia
S. agalactiae (group B)
what is primarily found in moist skin folds
S. aureus
what are the 2 stapylococcus species associated w disease
S. aureus S. epidermidis
Normal Microbiota of the Skin, opportunistic pathogen
S. epidermidis
cocci that most commonly form pairs
S. pneumoniae
form unpigmented, alpha hemolytic conlonies on blood agar
S. pneumoniae
Bacteremia and endocarditis
S. pneumoniae can enter the blood through lacerations or tissue damage
What causes glomerulonephritis?
S. pyogenes
Viridans group streptococci
S. sanguins, S. mutans, S. mitis
which staphylococcus species is cougulase neg?
Staphyloccocus epidermidis (turns pink, - manitol)
What causes endocarditis?
Staphylococcus
What causes pneumonia?
Staphylococcus
what causes osteomalitis
Staphylococcus
Folliculitis
Staphylococcus aureus
Impetigo
Staphylococcus aureus
Scalded skin syndrome
Staphylococcus aureus
coagulase positive
Staphylococcus aureus (yellow)
Coagulase negative
Staphylococcus epidermidis (pink)
what causes bacteremia
Staphylococcus species
Group B Streptococcus
Streptococcus agalactiae
Group A Streptococcus
Streptococcus pyogenes
What causes necrotizing fasciitis?
Streptococcus pyogenes
What causes rheumatic fever?
Streptococcus pyogenes
Which of the following bacteria is the primary cause of necrotizing fasciitis? Clostridium perfringens Staphylococcus aureus Streptococcus pyogenes Bacterioides fragilis
Streptococcus pyogenes
what causes phayrngitis and scarlet fever
Streptococcus pyogenes
rheumatic fever
Streptococcus pyogenes -untreated strep may lead to damage to heart valves and uscle -may be an autoimmune response
Streptococcus pneumoniae was originally named Diplococcus pneumoniae. Why was the genus name Diplococcus originally given to this organism? The prefix di- means "two", and these organisms are usually found in pairs under the microscope. The prefix di- means "four", and these organisms are usually found in groups of four under the microscope. The prefix di- means "two", and on agar plates, the colonies are found in groups of two. The prefix di- means "four", and on agar plates, the colonies are found in groups of four.
The prefix di- means "two", and these organisms are usually found in pairs under the microscope.
prevention of S. pneumoniae
Vaccine made from purified capsular material
what is used to treat MRSA
Vancomycin
alpha-hemolytic streptococci
Viridans group
In which of the following cases would you suspect wound botulism? A person injures herself while gardening. Four days later she begins to feel weak and dizzy, with blurred vision and progressive paralysis. A person injures herself by stepping on a rusty garden tool while gardening. Within a week, her jaw and neck muscles begin to tighen and she begins to sweat profusely. A person injures herself with a sharp knife while cutting vegetables for dinner. Her wound becomes inflamed and warm to the touch and about four days later she develops a fever and chills. A person injures herself in a minor car accident. Within two days she develops redness, swelling, and pus at the injury site.
a person injures herself while gardening. four days later she begins to feel weak and dizzy, with blurred vision and progressive paralysis
necrotizing fasciitis
a severe infection caused by Group A strep bacteria
necrotizing fasciitis
a severe infection caused by Group A strep bacteria -flesh eatin
TSS toxin
absorbed into blood -causing: fever, vomiting, rash, Low BP
An appropriately stained smear was prepared of a sputum specimen obtained from the sick woman on Lance's flight. Using oil-immersion magnification on your microscope, what would you observe that would aid in the diagnosis of tuberculosis?
acid-fast rods
Mycobacterium tuberculosis is considered a(n) __________.
aerobe
mycobacterium is an (aerobic/ anaerobic) pathogen
aerobic
myobacterium is an _________ pathogen
aerobic
How is tuberculosis transmitted? fecal/oral route aerosol droplets released by a cough or sneeze sharing "dirty" needles between IV drug users drinking pasteurized milk
aerosol droplets released by a cough or sneeze
diphtheria
an acute bacterial infection of the throat and upper respiratory tract -caused by Corynebacterium diphtheriae -transmitted from person to person via respiratory droplets or skin contact
What is listeriolysin O? A toxin that paralyzes cell activity. An enzyme that destroys the cell membrane, leading to cell death. A protein that binds to actin filaments. An enzyme breaks the bacteria free from the phagosome.
an enzyme breaks the bacteria free from the phagosome
Bacillus is a faculatative __________
anaerobe
Clostridium is an obligate ___________
anaerobe
pathogenic strains of Bacillus produce?
anthrax toxins
How is C. diff treated?
antibiotics
How to treat anthrax?
antibiotics
Prevention of S. pyogenes
antibodies against M protein provide protection but diff strains so can recur
the primary treatment for food-borne botulism is (antibiotics/antitoxin/muscle relaxants).
antitoxin
what are the only other known hosts of Mycobacterium leprae besides humans
armidillos
Mycoplasma pneumoniae causes respiratory disease by? attaching to and ultimately killing the ciliated epithelial cells of the trachea. triggering inflammatory mediator release. infecting and killing alveolar macrophages. paralyzing the respiratory muscles. killing the epithelial cells of the alveoli.
attaching to and ultimately killing the ciliated epithelial cells of the treachea
Which of the following habits will best prevent infection due to listerosis? Avoid eating raw fruits and vegetables Wash your hands after handling pet feces. Avoid eating or drinking pasteurized dairy products. Avoid hard cheeses, such as cheddar.
avoid eating raw fruits and vegetables
S. agalactia are resistant to?
bacitracin
hemolysins S. aureus
can lyse blood cell to release iron
The presence of ________ can be used to distinguish Staphylococcus from other Gram-positive cocci. protein M kinases enterotoxins hemolysins catalase enzyme
catalase enzyme
Is staphylococcus areus catalase positive or negative?
catalase positive
To diagnose meningitis due to Listeria infection, physicians will first examine a patient's ___. cerebrospinal fluid blood fecal samples gall bladder
cerebrospinal fluid
S. pneumoniae infections occur most often in?
children and elderly
C. perfringens, C. difficile, C. botulinum, and C. tetani route from?
clostridium
Staphylococcus epidermidis characteristics include
coagulase negative faculatative anaerobe
Micrococcus luteum characteristics include
coagulase negative obligate aerobe
Staphylococcus aureus characteristics include
coagulase positive faculatative anaerobe
Low G + C Gram-Positive Bacteria
cocci: Staphylococcus, Streptococcus, Enterococcus Rods: Bacillus, Clostridium, Listeria, Mycoplasma
Enterococcus is found in the human?
colon
How does listeria enter the body?
contaminated food and drink
How are patients typically infected with listeriosis? Contaminated food or drink A tick bite Inhalation of dust particles Eating undercooked chicken
contaminated food or drink
Mycobacterium leprae grows best in?
cooler regions of the human body
rod shaped High G+C bacteria
corynebacterium myobacterium propionibacterium
how to diagnose Staphylococcal diseases
detect gram positive bacteria in grapelike arrangements
streptococci in pharynx are not
diagnostic
Corynebacterium diphtheriae causes
diphtheria
-results when infection spreads throughout the body -symptoms arise due to complications at the various sites
disseminated tb
Mycobacterium tuberculosis (does/ does not) requires oxygen to survive.
does
How might an infected patient transmit listeriosis to another human? during pregnancy Fecal-oral route. Aerosolized droplets in a cough. Through sexual contact.
during pregnancy
how is the only way listeria is passed from human to human?
during pregnancy
is a condition that affects the space between the outermost layer of the lungs and the layer touching the chest wall, known as the pleural space
empyema
What is empyema? Empyema refers to a pocket of pus in between the lung and the inner surface of the chest wall. Empyema refers to air in the pleural cavity. Empyema refers to blood in the pleural cavity. Septicemia refers to a pocket of pus in between the lung and the inner surface of the chest wall.
empyema refers to a pocket of pus in between the lung and the inner surface of the chest wall
Bacillus form
endospores
Clostridium forms
endospores
________ allow for survival in harsh conditions
endospores
important cause of HAIs
enterococcus
what of S. aureus stimulate symptoms associated w food poisoning
enterotoxins
antibiotics can become resistant to bacteria because of
enzymes
The skin lesions characteristic of cutaneous infections with Bacillus anthracis are pus-filled ulcers. acne. eschars. scarlatina. impetigo.
eschars
What is the best way to prevent nosocomial MRSA infections? All hospitalized patients should take antibiotics daily. People should be vaccinated with the MRSA vaccine. Everyone should wash their hands before eating and after contact with any potentially contaminated surface/person. All hospitalized patients should wear a surgical mask
everyone should wash their hands before eating and after contact w any potentially contaminated surface/person
Which of the following staphylococcal virulence factors produce the signs and symptoms of scalded skin syndrome? coagulase staphylokinase hyaluronidase leukocidin exfoliative toxin
exfoliative toxin
what causes cutaneous disease
exotoxin
Bacillus is a __________ anaerobe
faculatative
is staphylococcus epidermidis is an (facultative anaerobe/ obligate anaerobe)
faculatative anaerobe
staphylococcus aureus is an (facultative anaerobe/ obligate anaerobe)
faculatative anaerobe
signs of tuberculosis
fever, chest pain, coughing up blood, weight loss
The neurotoxins of Clostridium botulinum produce (flaccid/tetanic) paralysis by preventing muscle contraction.
flaccid
noninvasive disease of Staphylococcus
food poisoning -due to ingestion of enterotoxin-contaminated food -self limiting
Streptococcus agalactiae are cocci that
form chains
mycoplasma stains
gram negative, but is gram positive
is mycobacterium gram positive or gram negative
gram positive
mycobacterium is resistant to
gram staining
viridans group lack
group-specific carbs
The most significant streptococcal pathogens are found in which of the following Lancefield groups? groups B and D groups A and B groups A and D groups A, B, and D
groups A and B
how to prevent Staphylococcal diseases
hand antisepsis important to prevent HAI's
Actinmyocetes belong to what group
high G+C bacteria -fungus shaped
Nocardia belongs to what group
high G+C bacteria -fungus shaped
Corynebacterium belongs to what group
high G+C bacteria -rod
Mycobacterium belongs to what group
high G+C bacteria -rod
Clostridium: vegetative cells secrete potent?
histolytic toxins, enterotoxins, and neurotoxins
glomerulonephritis
inflammation of the glomeruli of the kidney following infection w S. pyogenes
Clostridium difficile is a member of the?
intestinal flora, its an opportunistic pathogen
all enterococci live in the?
intestinal tracts of animals
does listeria grow intracellular or extracellularly
intracellular
where does mycobacterium grow
intracellular
does mycobacterium grow outside cells or intracellular
intrcellular
Enterococcus is found in human colon, but can cause disease if?
introduced into other parts of body
hylaronidase and collagenase
invades host tissues
A characteristic symptom of necrotizing fasciitis is that the pain __________. occurs only during nighttime hours is almost insensible comes across as a cold sensation is disproportionate to the appearance of the infection
is disproportionate to the appearance of the infection
What is one virulence factor that differentiates Staphylococcus aureus from other species of staphylococci? It produces catalase. it can live on the surface of the skin and in cutaneous oil glands. It has a capsule. It can produce coagulase. it produces lipase.
it can produce coagulase
Enterococcus is distinguised from S. pneumoniae by the fact that?
it is not sensitive to bile. will grow in presence of bile slts
Why is necrotizing fasciitis so difficult to prevent? Mosquitos are almost impossible to eradicate. It forms endospores and can survive well in the environment. It is not susceptible to most antibiotics. It is part of the normal microbiota.
it is part of the normal microbiota
where can you find clostridium
its ubiquitos -found in soil, water, GI tracts of animals and humans
Members of the genus Mycoplasma are pleomorphic and stain Gram-negative because they have sterols in their cytoplasmic membranes. have mycolic acid in their cell walls. have a rudimentary cell wall. lack cytoplasmic membranes. lack cell walls.
lack cell walls
The viridands group cannot be grouped by?
lancefield system
how to diagnose Bacillus
large,nonmotile, gram-positive bacilli in lung or skin samples
Myobacterium leprae causes
leprosy
hansen's disease aka
leprosy
enters body in contaminated food and drink
listeria
human to fetus transmission
listeria
an enzyme that breaks the bacteria free from the phagosome
listeriolysin O
Listeria's virulence is directly related to its ability to
live within cells
Which of the following is a key diagnostic indicator of infection with Mycobacterium leprae? pus-filled abscesses blister-like lesions severe inflammation with swelling a distinctive red rash that lasts for days localized loss of the sense of touch
localized loss of the sense touch
Enterococcus belongs to what group
low G+C bacteria -cocci
Stapyhlococcus belongs to what group
low G+C bacteria -cocci
Streptococcus belongs to what group
low G+C bacteria -cocci
Bacillus belongs to what group
low G+C bacteria -rod
Clostriduim belongs to what group
low G+C bacteria -rod
Listeria belongs to what group
low G+C bacteria -rod
Mycoplasma belongs to what group
low G+C bacteria -rod
the mycolic acid in the cell walls of mycobacterium offers protection from?
lysis after phagocytosis
S. aureus virulence factors
many enzymes and toxins
Pneumococcal meningitis
meninges of brain spread via bacteremia -mortality rate higher than other causes of menigitis
treatment for Staphylococcal diseases
methicillin
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 Enterococcus. methicillin-resistant Staphylococcus aureus (MRSA). Staphylococcus epidermidis. Streptococcus pyogenes (group A streptococcus). Staphylococcus aureus.
methicillin-resistant Staphylococcus aureus (MRSA).
Pneumococcal pneumonia
most common disease caused by S. pneumoniae
S. pneumoinae are present in?
mouths and pharynges of most humans
A patient presents with a severe skin infection characterized by lesions that are swollen, draining sores. You learn that the patient is an avid gardener. Which of the following diseases should be suspected? erysipelas Hansen's disease tetanus mycetoma
mycetoma
what cell wall contains mycolic acid
mycobacterium
is staphylococcus epidermidis catalse positive or negative
negative
mycobacterium stains gram ________, but is gram ________
negative positive
S. agalactiae (Group B) diseases
neonatal bacteremia neonatal meningitis neonatal pneumonia
Streptococcus agalactiae is associated with which of the following diseases? neonatal meningitis neonatal bacteremia neonatal pneumonia both neonatal bacteremia and neonatal meningitis neonatal bacteremia, neonatal meningitis, and neonatal pneumonia
neonatal bacteremia, neonatal meningitis, neonatal pneumonia
S. agalactiae often infects?
newborns without specific antibodies
Do mycoplasma have a cell wall?
no
Does listeria produce toxins or enzymes?
no
Does mycoplasma have a cell wall?
no
is there a vaccine for walking pneumonia
no
Are Clostridium botulinum vegetative cells required to be present for foodborne botulism to occur? No, foodborne botulism is caused by the botulinum toxin produced by the bacteria, not the bacteria themselves. No, foodborne botulism is caused by the endospore form of Clostridium botulinum, not vegetative cells. Yes, the foodborne botulism can only be caused by infection with Clostridium botulinum vegetative cells. Yes, the foodborne botulism is caused by endotoxic shock, which occurs when the cell walls of Clostridium botulinum are disrupted.
no, foodborne botulism is caused by the botulinum toxin produced by the bacteria, not the bacteria themselves
Are Clostridium botulinum vegetative cells required to be present for foodborne botulism to occur? No, foodborne botulism is caused by the botulinum toxin produced by the bacteria, not the bacteria themselves. Yes, the foodborne botulism is caused by endotoxic shock, which occurs when the cell walls of Clostridium botulinum are disrupted. No, foodborne botulism is caused by the endospore form of Clostridium botulinum, not vegetative cells. Yes, the foodborne botulism can only be caused by infection with Clostridium botulinum vegetative cells.
no. food born botulism is caused by the botulinum toxin produced by the bacteria, not the bacteria themselves
Staphylococcal diseases
noninvasive, cutaneous, systemic
Actinomyces are ______ microbiota. Produces ________ infections in numerous sites
normal opportunistic
Streptococcus pyogenes (Group A) often cause disease when?
normal microbiota are depleted
Clostridium is an ___________ anaerobe
obligate
If ampicillin is the prescribed treatment for listeriosis, why might a physician instead prescribe trimethoprim-sulfamethoxazole? Ampicillin further decreases the ability of the immunocompromised to fight infection. Trimethoprim-sulfamethoxazole is a superior antibiotic. Patients may be allergic to penicillins. Listeriosis is often accompanied by a fungal infection.
patients may be allergic to penicillins
treatment for Streptococcus pyogenes
penicillin
Treatment of S. pneumoniae
penicillin (some resistant strains have emerged)
treatment for S. agalactiae
penicillin or ampicillin
Streptococcus pyogenes (Group A) typically infects the?
phayrnx or skin
Which of the following would be diagnostic for the presence of Corynebacterium diphtheriae in a clinical specimen? "fried egg" appearance in cultures dull, yellow raised colonies on Lowenstein-Jensen agar "tumbling" motility at room temperature pleomorphic bacteria in palisade formations
pleomorphic bacteria in palisade formations
pneumococcal diseases
pneumococcal pneumonia bacteremia and endocarditis pneumococcal meningitis
results from the initial infection with M. tuberculosis
primary tuberculosis
Treatment of Tuberculosis
prolonged treatment with multiple antibiotics
Which of the following is an effective way to prevent many staphylococcal infections? proper food canning techniques avoiding exposure to soil proper cleansing of wounds control of the organism in animals
proper cleansing of wounds
In its role in the development of acne, (Propionibacterium/Staphylococcus/Actinomyces) typically grows in sebaceous glands of the skin.
propionibacterium
Diagnosis of S. agalactiae
rapid test used to identify group B Strep.
One of the primary reasons Myobacterium tuberculosis is able to evade the body's immunity is that it __________. produces a capsule resists digestion by phagocytes hides within host epithelial cells is camouflaged in hyaluronic acid
resists digestion by phagocytes
How is diphtheria transmitted?
respiratory droplets
mycoplasma attaches to cells of the
respiratory tract
Which of the following diseases is considered an autoimmune disease triggered by bacterial infection? glomerulonephritis caused by the group A streptococci rheumatic fever impetigo toxic shock syndrome scarlet fever
rheumatic fever
High G+C Gram Positive Bacteria
rods: corynebacterium, Mycobacterium, Propionibacterium fungus shaped: Actinomycetes, Nocardia
what can occur following streptococcal pharyngitis
scarlet fever
Untreated streptococcal pharyngitis may progress to necrotizing fasciitis. scarlet fever. rheumatic fever. scarlet fever or rheumatic fever. scarlet fever or necrotizing fasciitis.
scarlet fever or rheumatic fever
In approximately 10% of patients tubercles rupture and reactivate infection. This is known as _____ tuberculosis. primary disseminated secondary tertiary
secondary
reestablishment of active infection after period of dormancy
secondary tuberculosis
myobacterium is _______ growing
slow
Where is Listeria monocytogenes found?
soil, water, mammals, birds, fish, and insects
Nocardia is a common inhabitant of?
soils rich in organic matter
what produces TSS
some Staphylococcus strains
A strain of Staphylococcus aureus that loses the ability to produce staphylokinase will be unable to do which of the following? grow on the surface of the skin spread to new locations in the body degrade beta-lactam antibiotics evade immune cells
spread to new locations in the skin
cocci low G+C bacteria
staphylococcus streptococcus enterococcus
which staphylococcus species is catalse positive
staphylococcus aureus (turns yellow, + manitol)
Enterotoxins of S. aureus
stimulate symptoms associated w food poisoning
All of the following methods of food storage or preparation except which of the following can help prevent foodborne botulism? heating canned foods to at least 80 degrees Celsius for 20 minutes before consuming storing canned foods in the refrigerator storing canned foods at room temperature maintaining an acidic environment below ph 4.5
storing canned foods at room temp
Which practice would NOT be a good way to prevent foodborne botulism? Maintaining an acidic environment below ph 4.5. Storing canned foods at room temperature. Heat canned foods to at least 80 degrees Celsius for 20 minutes before consuming. Storing canned foods in the refrigerator.
storing canned foods at room temp
Streptococcus pyogenes causes
strep throat, scarlet fever, rheumatic fever, necrotizing fascitis, glomerulonephritis
One of the virulence factors produced by Group A Streptococcus is __________, which can kill neutrophils, the immune system's first responders. exotoxin A Hyaluronidase streptolysin S Streptokinase
streptolysin S
Why does tuberculosis involve months of antibiotic treatment? The bacteria go into a dormant state. The bacteria become resistant to the medications after only a month of treatment. The bacteria grow very slowly. The antibiotic treatment is so toxic, it can only be given in very small doses.
the bacteria grow very slowly
A patient has a positive tuberculin skin test. Without any other information about the patient, which of the following is the most accurate interpretation of this result? The patient has disseminated tuberculosis. The patient has been exposed to M. tuberculosis. The patient is able to transmit M. tuberculosis to other individuals. The patient has primary tuberculosis.
the patient has been exposed to M. tuberculosis
diphtheria toxin causes
the signs and symptoms of disease
one cause of dental caries and dental plaques
the viridans group
The polymerization of actin filaments allows Listeria to form pseudopods extending from the host cell. How does this aid the bacteria during infection? They are able to spread to neighboring cells sheltered from detection by the host immune system. The pseudopods shelter the bacteria from destruction by lysosomes. The pseudopods control the movement of the host cells. The pseudopods form extracellular vesicles similar to endospores.
they are able to spread to neighboring cells sheltered from detection by the host immune system
Over 90% of Staphylococcus aureus isolates are penicillin-resistant. Why? they produce staphylokinase. they produce β-lactamase. they have loosely organized polysaccharide slime layers which protects their cell wall. They have a coating of protein A. they produce coagulase.
they produce β-lactamase
The use of super-absorbent tampons has been implicated in which of the following staphylococcal diseases? empyema furuncles toxic shock syndrome endocarditis
toxic shock syndrome
What does C. botulinum do?
toxins bind to neurons irreversibly and prevent muscle contractions
S. pneumoniae causes disease when?
travel to the lungs
Adult foodborne botulism can be prevented by thoroughly cooking food (minimum 80°C for 20 minutes) before it is eaten. t or f
true
Clostridium is ubiquitos t or f
true
Mycobacterium leprae bacteria do not grow in cell-free culture complicating research t or f
true
Mycobacterium tuberculosis is capable of inhibiting phagocytosis t or f
true
Staphylococcus aureus food poisoning is long-lasting because ingested bacteria produce enterotoxins in the digestive system. t or f
true
Staphylococcus can produce toxins t or f
true
The bacterium Streptococcus mutans has a major role in the development of dental plaque and caries. True False
true
individuals with lowered immunity at greatest risk for infection (tuberculosis) t or f
true
listeria is a faculatative intracellular parasite t or f
true
listeriosis can be passed from mother to fetus t or f
true
pregnant women can transmit Listeria to their fetus t or f
true
How do clinicians primarily screen for tuberculosis in patients? Tuberculin skin test Throat swab Urinalysis Blood test
tuberculin skin test
respiratory disease caused by Mycobacterium tuberculosis
tuberculosis
Vancomycin
used to treat MRSA
methicillin
used to treat Staphylococcal diseases
Streptococcus pyogenes (Group A) spreads via?
via respiratory droplets
many produce a green pigment when grown on blood media
viridans group
Which of the following streptococci is associated with dental caries? Streptococcus pneumoniae viridans streptococci Streptococcus arginosus Streptococcus pyogenes Streptococcus equisimilis
viridans streptococci
Mycoplasma pneumoniae
walking pneumonia
Can Listeria cause meningitis in certain at-risk groups
yes
are cases of tb declining in US
yes
do enterococci lack capsules
yes
does listeria live in cells
yes
is C. diff and opportunistic pathogen?
yes
is there a vaccine for anthrax
yes (for those at risk, i.e. military)
How does β-lactamase contribute to the virulence of Staphylococcus spp.? β-lactamase destroys neutrophils. β-lactamase triggers blood clot formation. β-lactamase breaks down penicillin and cephalosporin. β-lactamase breaks down hyaluronic acid in the matrix between cells.
β-lactamase breaks down penicillin and cephalosporin.