Microbiology Unit 2 Exam

Choose the component that provides for a stronger cell wall structure in gram-positive cells as compared to gram-negative cells.

Thick peptidoglycan layer

What was the main purpose of this MMWR article?

To recommend best practices for response to an anthrax crisis

MRSA infections that occur in individuals who have had no recent history in hospitals or clinics are termed community-acquired or CA-MRSA cases.

True

Neonatal meningitis is almost always a result of an infection transmitted by the mother, either in utero or during the birthing process.

True

Pregnant women are an important risk group for group B Streptococcus infections due to their ability to pass this dangerous organism to the infant during the birthing process.

True

The neurotoxin produced by Clostridium tetani blocks the inhibition of muscle contraction resulting in spastic paralysis.

True

The rash of secondary syphilis ________.

Usually disappears spontaneously after a few weeks.

"Rice-water stools" are associated with disease caused by which organism?

Vibrio cholerae

The outcome of the Gram stain is based on differences in the cell's _____.

Wall

The most immediate and important treatment needed to prevent death in cholera victims is ________.

Water and electrolyte replacement

Which of the following is an example of a biofilm commonly found in the human body?

Dental plaque

The chancre of syphilis __________.

Develops into a lesion with firm margins and an ulcerated, central crater.

Formation of a pseudomembrane in the back of the throat is seen in ________.

Diphtheria

Which of the following is the most common form of microbe transmission in impetigo?

Direct contact

What form of Bacillus anthracis is likely to be used in a bioterrorism event?

Endospores

Lipopolysaccharide is a major component of gram-negative outer membranes, can stimulate shock and fever, and is also referred to as _________.

Endotoxin

The virulence of Vibrio cholerae is due to its ________.

Enterotoxin

The bright red rash and fever of scarlet fever are due to ________.

Erythrogenic toxin

Infection travels to the middle ear by way of the ________.

Eustachian (auditory) tubes

The toxin of Staphylococcus aureus strains that causes blisters and desquamation of skin in scalded skin syndrome is ________.

Exfoliative toxin

Extensively drug-resistant tuberculosis, while harder to treat because some antibiotics are ineffective, has a similar prognosis and recovery rate compared to nonresistant tuberculosis.

False

Choose the bacterial appendage that enables bacteria to stick to one another, to inanimate surfaces, and to host cells.

Fimbriae

Which of these pairs is incorrectly matched?

Fimbriae-motility

Which of the following is not true of Streptococcus pyogenes?

Forms spores

Anthrax primarily affects which three body systems?

Gastrointestinal, Respiratory, Integumentary

The latency period of syphilis can last up to ________.

20 years or more

Which of the following statements describes the main virulence factor of E. coli O157:H7?

A bacteriophage-encoded exotoxin

What is a biofilm?

A group of bacteria that accumulate in layers and secrete an protective extracellular material

Infections caused by Staphylococcus aureus include all of the following except ________.

Acne

Lyme disease involves ________.

All Choices are correct (treatment with antimicrobials, crippling polyarthritis, and cardiovascular and neurological problems. People having contact with ticks, early symptoms are fever, headache, and stiff neck).

Meningococcemia is ________.

All of the choices are correct ( best treated with ceftriaxone, penicillin or chloramphenicol. Associated with high fever, vascular collapse, hemorrhage, and petechiae. Started from a nasopharyngeal infection, and caused by a gram-negative diplococcus).

Treponema pallidum ________.

All of the choices are correct ( can cross the placenta, has a hooked tip to attach to the epithelium, is transmitted by direct sexual contact, has humans as the reservoir).

Cholera symptoms include ________.

All of the choices are correct ( loss of blood volume, hypotension, tachycardia & shock, copious watery diarrhea, acidosis, sunken eyes, and thirst.)

Salmonelloses are ________.

All of the choices are correct ( not caused by Salmonella typhi, associated with undercooked poultry and eggs, and reptile and rodent feces, types of gastroentertitis with vomiting and diarrhea, treated with fluid and electrolyte replacement

A diagnosis of tuberculosis involves a(n) ________.

All of the choices are correct (acid-fast stain of sputum, sputum culture, TB skin test, chest x-ray)

Neisseria gonorrhoeae is ________.

All of the choices are correct (call gonococcus, the cause of gonorrhea, virulent due to fimbriae and a protease that inactivates IgA, and the cause of ophthalmia neonatorum)

Escherichia coli infections ________.

All of the choices are correct (can be self-limiting with the only treatment being rehydration, are often transmitted by fecal-contaminated water and food, involve enterotoxin in traveler's diarrhea, have been due to undercooked meat).

Helicobacter pylori causes ________.

All of the choices are correct (duodenal ulcers, stomach ulcers, gastritis, increased risk for stomach cancer)

Superantigens ________.

All of the choices are correct (induce production of tumor necrosis factor, include erythrogenic toxin, can initiate a cascade of immune responses, included streptolysin O)

Endospores are _____________.

All of the choices are correct (resistant to heat and chemical destruction, metabolically inactive, resistant to destruction by radiation, living structures)

Extrapulmonary TB can involve the ________.

All of the choices are correct (spine, long bones, brain, kidneys)

Tuberculin skin testing ________.

All of the choices are correct (will be positive if the person has active TB, uses a purified protein filtrate of Mycobacterium tuberculosis, will be positive if the person has had previous exposure to TB, injects PPD intradermally.

Bacillus anthracis exhibits characteristics that make it a model organism to be exploited as an agent of bioterrorism. Those characteristics include ________.

All of the choices reflect characteristics that make B. anthracis a candidate for bioterrorism.

Characteristics of fimbriae:

Allow bacterial cells to avoid phagocytosis, Allow bacterial cells to colonize host tissues, hollow tubes for material exchance, short appendages, participate in biofilm formation.

The term that refers to flagella at both poles is _____.

Amphitrichous

The major virulence factor of Corynebacterium diphtheriae that causes serious systemic effects is ________.

An exotoxin

Rheumatic fever is caused by ___________.

An immunological cross-reaction in which anti-streptococcal antibodies target the heart.

Gram-negative bacteria

Are less susceptible to antibiotics that target peptidoglycan than gram-positive o rganisms.

Plasmids ___________.

Are often the site of pathogenic genes

The two functions of bacterial appendages are ________.

Attachment and motility

Why are biofilms important in infectious disease?

Bacteria in biofilms are often protected from antibiotics.

The causative organism of whooping cough is ________.

Bordetella pertussis

The causative agent of Lyme disease is ________.

Borrelia burgdorferi

Impetigo is caused by ________.

Both Staphylococcus aureus and Streptococcus pyogenes

What external structure is found in Bacillus anthracis and contributes to its virulence?

Capsule

Which external structure directly impacts the effectiveness of the host immune system?

Capsule

Which structure protects bacteria from being phagocytized by white blood cells?

Capsule

What type of macromolecule makes up the bacterial capsule?

Carbohydrates

The site(s) for most ATP synthesis in bacterial cells is(are) the _____.

Cell membrane

If bacteria living in salty seawater were displaced to a freshwater environment, the cell structure that would prevent the cells from rupturing is the ________.

Cell wall

The movement of bacteria toward or away from a chemical stimulus is _________.

Chemotaxis

What does the capsule typically look like on a stained smear when viewing under the light microscope?

Clear halos around the cells

Neisseria meningitidis is transmitted by ________.

Close contact

Which of the following is not true of whooping cough?

Coldlike symptoms are common for the paroxysmal stage

All of the following pertain to Neisseria meningitidis except ________.

Common cause of bacterial pneumonia

Lipopolysaccharide is an important cell envelope component of _____________.

Gram-negative bacteria

Streptococcal pharyngitis involves all of the following except ________.

It is viral in origin

A culture of Klebsiella colonies is smooth, indicating the presence of a capsule. A culture of Pseudomonas shows rough colonies. Based on this information alone, which species is likely to be more pathogenic?

Klebsiella

The term that refers to the presence of a tuft of flagella emerging from the same site is _____.

Lophotrichous

The white-footed mouse, deer, and deer ticks are important to maintaining the transmission cycle associated with ________.

Lyme Disease

Erythema migrans, a bull's-eye rash, at the portal of entry is associated with ________.

Lyme disease

The enzyme _______, found in tears and saliva, can hydrolyze the bonds in the glycan chains of certain bacterial cell walls.

Lysozyme

The tubercles formed in primary tuberculosis are caused by an influx of ________.

Mononuclear cells

Which of the following organisms is most problematic with respect to the resistance to antibiotics?

Mycobacterium tuberculosis

When the centers of tubercles break down into _____ lesions, they gradually heal by calcification that replaces normal lung tissue.

Necrotic caseous

Choose the microorganism that is the causative agent of the most serious acute form of bacterial meningitis to test your understanding of this disease.

Neisseria meningitidis

Choose the substance or condition that triggers sporogenesis among endospore-forming bacteria.

Nutrient depletion

Which of the following is not true of cellulitis?

Occurs in the epidermis

Choose the phrase that best describes septicemia.

Occurs when microorganisms are actively multiplying in the blood

E. coli O157:H7 characteristics include all the following except it ________.

Only causes occupational illness in people who work with animals

Select those structures that are found in a gram-negative cell envelope.

Outer membrane, cell membrane, Lipopolysaccharide, Thinn layer of peptidoglycan, Periplasmic space

Which of the following is the current effective treatment for syphilis?

Penicillin G

The term that refers to the presence of flagella over the cell surface is _____.

Peritrichous

Untreated streptococcal pharyngitis can lead to all of the following except ________.

Pertussis

A cell contains a fertility (F) plasmid that allows it to produce a structure for exchanging DNA with another cell. What structure is coded for by the genes of this plasmid?

Pilus

Which structure plays a direct role in the exchange of genetic material between bacterial cells?

Pilus

The presence of variation in the size and shape of bacterial cells of the same species is known as _______.

Pleomorphism

Which of the following pertains to diphtheria?

Prevented by the DTaP immunization

Which is not true of Clostridium difficile?

Produces "rice-water" stools

The function of bacterial endospores is ________.

Protection of genetic material during harsh conditions

The most immediate result of destruction of a cell's ribosomes would be __________.

Protein synthesis would stop

According to data from anthrax cases in the United States over a ten year period, what was the most common sign of inhalation anthrax infection?

Rapid heart beat

Permanent cardiovascular and neurological damage is seen in which stage of syphilis?

Tertiary

Pertussis has the following characteristics except ________.

The catarrhal stage has persistent, hacking coughs wit "whoops"

Why is the capsule considered a virulence factor?

The presence of the capsule allows a bacterium to evade the immune system and cause damage to the host

The main contributing factor to the evolution of MDR-TB is ________.

The slow growth of Mycobacterium tuberculosis requires antibiotic therapy for months rather than days, which is hard to sustain in some populations; cutting the regimen short allows the resistant bacteria to flourish

The beta-hemolysis of blood agar observed with Streptococcus pyogenes is due to the presence of _______.

Streptolysin

Lysozyme is most effective against _________.

Gram-positive organisms

Syphilitic lesions called _______ develop in the liver, skin, bone, and cartilage during the tertiary stage of syphilis.

Gummas

The difference in cell wall structure of Mycobacterium and Nocardia compared to the typical gram-positive bacterial cell wall structure is that they ________.

Have a predominance of unique, waxy lipids

Staphylococcus aureus is part of the differential diagnosis of which of the following diseases?

Impetigo

Which is incorrect about Staphylococcus aureus food intoxication?

Ingestion of the pathogen allows it to multiply and damage the GI tract lining.

The secondary stage of syphilis __________.

Is a time when the pathogen enters and multiplies in the blood.

All of the following pertain to Clostridium difficile infection except it ________.

Is due to ingestion of contaminated, improperly stored, cooked meats and gravies.

What characteristics of Bacillus anthracis contribute to its classification as a Category A Pathogen for biodefense?

It has several portals of entry into the body, High mortality rate, Disperses easily, Spores are resistant to harsh environmental conditions

Choose the statement that best describes staphylococcal scalded skin syndrome.

It is an exotoxin-mediated disease that can be compared to a systemic form of impetigo

Which of the following does not pertain to endotoxin?

It is found in acid-fast bacterial cell walls

Bacterial endospores usually function in _________.

Survival

MRSAs are Staphylococcus aureus strains that are ________.

Resistant to penicillin derivatives

Streptococcus pyogenes causes all of the following except ________.

Scalded skin syndrome

During which stage of syphilis does fever, lymphadenopathy, and a red to brown rash occur?

Secondary

In anthrax, Bacillus anthracis gains access to the bloodstream where it multiplies in large numbers resulting in death from an overwhelming ________.

Septicemia

Which of the following is not true of staphylococcal scalded skin syndrome (SSSS)?

Split in skin occurs between the dermis and epidermis

If you looked at a _______ under the microscope, you would likely see an irregular cluster of spherical cells.

Staphyloccus

A common food intoxication is caused by enterotoxin-producing strains of ________.

Staphylococcus aureus

A chain of rod-shaped cells would be called a(an) _____.

Streptobacillus

The predominant causative organism of dental caries seem to be ________.

Streptococcus mutans

Choose the microorganism that is the most common cause of bacterial meningitis in adults to test your understanding of this disease.

Streptococcus pneumoniae

The most common causative agent of otitis media is ________.

Streptococcus pneumoniae