Micro Exam 3 Chapter 19

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

A) Clostridium difficile

Which of the following statements about Bacillus anthracis is FALSE? A) It is primarily a disease of humans. B) It produces endospores. C) It has a capsule. D) It normally dwells in the soil and can survive in the environment for centuries or longer. E) It can be lethal even after treatment because antimicrobial drugs do not inactivate accumulated anthrax toxin.

A) It is primarily a disease of humans.

Which of the following statements regarding Streptococcus pyogenes is FALSE? A) It produces protein A, which inhibits opsonization. B) It is beta-hemolytic. C) It has group A Lancefield antigens. D) It produces streptolysins. E) It can be lysogenized by a temperate bacteriophage to produce erythrogenic toxins.

A) It produces protein A, which inhibits opsonization.

Which of the following statements concerning tetanus is FALSE? A) Its only source is from deep puncture wounds from rusty nails B) Its toxin causes simultaneous contraction of both muscles in an antagonistic pair. C) It is a small, motile, obligate anaerobe. D) It produces a terminal endospore that gives the cell a distinctive "lollipop" appearance. E) Its diagnostic feature is characteristic muscle contractions, which are often noted too late to save the patient.

A) Its only source is from deep puncture wounds from rusty nails

Which of the following is an antiphagocytic factor of Staphylococcus? A) protein A B) catalase C) hemolysin D) protein M E) hyaluronidase

A) protein A

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

A) viridans streptococci

How does the toxin from Clostridium tetani produce its action?

B) The smaller polypeptide of its toxin can block the release of inhibitory neurotransmitters by inhibitory neurons in the central nervous system.

In countries where tuberculosis is common, people are vaccinated with _____, which contains attenuated Mycobacterium bovis bacteria.

BCG

Which of the following bacteria divide by "snapping division" in which daughter cells remain attached in characteristic V-shapes? A) staphylococci B) enterococci C) Corynebacterium D) Listeria E) Mycobacterium

C) Corynebacterium

Which of the following staphylococcal virulence factors produce the signs and symptoms of scalded skin syndrome? A) hyaluronidase B) staphylokinase C) exfoliative toxin D) leukocidin E) coagulase

C) exfoliative toxin

Which of the following diseases is considered an autoimmune disease triggered by bacterial infection? A) glomerulonephritis caused by the group A streptococci B) scarlet fever C) rheumatic fever D) impetigo E) toxic shock syndrome

C) rheumatic fever

Painful swelling and rapidly spreading subcutaneous tissue necrosis is characteristic of a wound infection by

Clostridium perfringens.

Which of the following bacteria produce one of the most deadly bacterial toxins known? A) Clostridium perfringens B) Clostridium difficile C) Clostridium tetani D) Clostridium botulinum E) Corynebacterium species

D) Clostridium botulinum

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.

D) It is considered a common complication of pyoderma.

Which of the following statements about diphtheria is FALSE? A) All species of Corynebacterium may be pathogenic. B) Its toxin interferes with eukaryotic protein synthesis. C) It produces a characteristic pseudomembrane that can adhere to tissues in the throat. D) Its growth on Loffler's medium is used for absolute diagnosis of the bacterium. E) Its toxin can be absorbed into the blood from cutaneous lesions leading to severe complications.

D) Its growth on Loffler's medium is used for absolute diagnosis of the bacterium.

Which of the following is a key diagnostic indicator of infection with Mycobacterium leprae? A) blister-like lesions B) a distinctive red rash that lasts for days C) pus-filled abscesses D) localized loss of the sense of touch E) severe inflammation with swelling

D) localized loss of the sense of touch

Members of the genus _______ are part of the normal microbiota of humans.

Enterococcus

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

Enterococcus.

T/F A person comes into the clinic with a wound that is severely inflamed, very painful, and turning black and "bubbly." The diagnosis is leprosy.

FALSE

T/F Mycobacterium tuberculosis is able to persist and be spread in aerosols due to its ability to produce endospores.

FALSE

T/F Staphylococcus aureus food poisoning is long-lasting because ingested bacteria produce enterotoxins in the digestive system.

FALSE

T/F Streptococcus pyogenes commonly causes streptococcal toxic shock syndrome in otherwise healthy people.

FALSE

An opportunistic pathogen frequently seen in AIDS patients, ________ spreads rapidly to various organs.

Mycobacterium avium-intracellulare

A sample of fluid from the lungs contains microbes that grow in filaments or clumps. The cells stain poorly in the Gram stain and are a pink-red when acid-fast stained. The bacteria in the sample are

Mycobacterium species.

Mycetoma, which is a painless long-lasting infection characterized by swelling, pus production, and draining sores, is commonly caused by

Nocardia

In its role in the development of acne, ______________ typically grows in sebaceous glands of the skin.

Propionibacterium

Increased sebum secretion can fuel the overgrowth of the opportunistic pathogen ________ in its normal habitat, leading to disease.

Propionibacterium acnes

Immunization for ________ may reduce the incidence of otitis media and sinusitis.

Streptococcus pneumoniae

Otitis media may lead to dangerous meningitis in children due to infection with

Streptococcus pneumoniae.

T/F Adult foodborne botulism can be prevented by thoroughly cooking food (minimum 80°C for 20 minutes) before it is eaten.

TRUE

T/F Group A streptococci are considered more virulent if their cytoplasmic membrane contains M protein.

TRUE

T/F Staphylococcus aureus can produce a toxin that dissolves the desmosomes that hold the adjoining cytoplasmic membranes of cells together and causes the patient's skin cells to separate.

TRUE

T/F The bacterium Streptococcus mutans has a major role in the development of dental plaque and caries.

TRUE

T/F The primary reservoir of anthrax is herbivores.

TRUE

T/F The respiratory infection known as primary atypical pneumonia is caused by Mycoplasma pneumoniae.

TRUE

A lab report on a respiratory patient's sample contains the notation MDR-TB. What does this mean?

The two standard drugs for TB, isoniazid and rifampin, are not effective.

How do group A streptococci camouflage themselves from white blood cells?

They have hyaluronic acid capsules.

Over 90% of Staphylococcus aureus isolates are penicillin-resistant. Why?

They produce β-lactamase.

Streptococci are frequently classified by

Lancefield antigen designations.

Eating food contaminated with ________ may result in meningitis in at-risk persons.

Listeria monocytogenes

Streptococcus pyogenes produces __________ and thereby avoids phagocytosis.

M protein

______ is resistant to numerous antimicrobial agents; therefore, vancomycin is usually used for these infections.

MRSA

What is the most common disease caused by Propionibacterium?

acne

The primary treatment for food-borne botulism is __________.

antitoxin

Mycoplasma pneumoniae causes respiratory disease by

attaching to and ultimately killing the ciliated epithelial cells of the trachea.

Enterococcus faecalis bacteria can be distinguished from other Gram-positive cocci because enterococci

can grow in the presence of bile salts.

The Quellung reaction is a test to detect

capsule antigens.

The presence of ________ can be used to distinguish Staphylococcus from other Gram- positive cocci.

catalase enzyme

The bacterium Clostridium ____________ is an opportunistic pathogen that can cause a severe, potentially fatal diarrhea.

difficile

When streptococcal infections involve the skin and surrounding lymph nodes, triggering pain and inflammation, the condition is known as __________.

erysipelas

The skin lesions characteristic of cutaneous infections with Bacillus anthracis are

eschars

The neurotoxins of Clostridium botulinum produce ________ paralysis by preventing muscle contraction.

flaccid

When observed in the lab Mycoplasma stains ________.

gram-negative

The ability to produce _________ enables Staphylococcus aureus to penetrate and spread through tissues.

hyaluronidase

What is one virulence factor that differentiates Staphylococcus aureus from other species of staphylococci?

it can produce coagulase

Members of the genus Mycoplasma are pleomorphic and stain Gram-negative because they

lack cell walls

Listeria virulence is directly related to its ability to

live within cells and thus avoid exposure to the immune system of its host.

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

methicillin-resistant Staphylococcus aureus (MRSA).

Streptococcus agalactiae is associated with which of the following diseases?

neonatal bacteremia, neonatal meningitis, and neonatal pneumonia

Bacterial food poisoning resulting from Clostridium __________ contamination is characterized by watery diarrhea accompanied by intestinal cramping but not fever, and it resolves in about a day.

perfringens

The pathogenicity of primary tuberculosis is due to the fact that the mycobacteria

prevent fusion of lysosomes with vesicles

Infection with Corynebacterium diphtheriae leads to the formation of _________which can severely impair respiratory function.

pseudomembranes

Strep throat may progress to ________, characterized by a skin rash and a bright red swollen tongue.

scarlet fever

Untreated streptococcal pharyngitis may progress to

scarlet fever or rheumatic fever.

Mycobacterium leprae primarily infects

skin cells

Common sources of Listeria are undercooked meats and vegetables and unpasteurized ___________.

soft cheeses

Anthrax, which means "charcoal" in Greek, derives its name from

the black eschars it produces on human skin.

What differentiates virulent strains of Streptococcus pneumoniae from nonvirulent strains?

the presence of a polysaccharide capsule

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 a likely diagnosis?

toxic shock syndrome

A "summer cold" that lasts for weeks and is characterized by sore throat, mild fever, dry cough, and malaise may be ______________- pneumonia.

walking