MICRO BMEX Flashcards
Meningococcemia is
A. common during gonorrhea
B. associated with vascular hemorrhage and petechiae
C. caused by a Gram-positive diplococcus
D. All of these choices are correct
B. associated with vascular hemorrhage and petechiae
In the human _______ Escherichia coli begins to colonized while establishing infestation.
A. lungs
B. intestine
C. stomach
D. kidneys
D. kidneys
An 8-month-old infant has been brought to the ER with a high fever. Her parents indicated that she has not been eating or drinking well and has been very irritable until the last few hours during which she has only been minimally responsive. Suspecting meningitis, a spinal tap is done and the SF sample is sent to the lab for analysis. The white blood cell count on the sample is profoundly elevated, the protein content is elevated, and the glucose level is depressed. The Gram-stained smear shows Gram-positive cocci in pairs. Cultures are done and after overnight incubation, alpha hemolytic colonies are observed on the blood plate. These colonies contain Gram-positive cocci, which are catalase negative. An optochin susceptibility test is done and there is a large zone of inhibition around the disk. What is the identification of this isolate?
A. Viridans streptococci
B. Streptococcus pneumoniae
C. Neisseria meningitidis
D. Enterococcus faecalis
B. Streptococcus pneumoniae
In the lab, students were given two samples of bacteria; both were exposed to hydrogen peroxide. Bacterial sample #1 exhibited bubbles, whereas bacterial sample #2 did not. What enzyme was detected in sample #1?
A. Hydrolase
B. Helicase
C. Catalase
D. Lipase
C. Catalase
The most immediate result of destruction of a cell’s ribosomes would be
A. destruction of the cell’s DNA
B. formation of glycogen inclusions
C. material would not be able to cross the cell membrane
D. protein synthesis would stop
C. material would not be able to cross the cell
membrane
The M protein of Streptococcus pyogenes
A. is the basis for the organism belonging to Lancefield Group A
B. gives rise to a zone of beta hemolysis on blood agar
C. is also called streptokinase
D. protects against phagocytosis and enhances adherence
D. protects against phagocytosis and enhances adherence
Which of the following is NOT a similarity between Bacillus cereus and Clostridium perfringens?
A. They are both Gram-positive, endospore-forming bacteria
B. They are both obligate anaerobes
C. Symptoms of infection with either bacteria include nausea, vomiting, and diarrhea
D. They cause disease through contaminated foods
B. They are both obligate anaerobes
Which of the following makes possible the differentiation of members of the genus Mycobacterium and the genus Nocardia from other bacteria?
A. The capsule stain
B. The presence of flagella
C. The Gram stain
D. The acid-fast stain
C. The Gram stain
All of the following pertain to endotoxins, except they
A. can stimulate fever in the human body
B. are found in acid-fast bacterial cell walls
C. are specific bacterial cell wall lipids
D. can cause shock in the human body
B. are found in acid-fast bacterial cell walls
Which of the following does NOT pertain to Clostridium difficile infection?
A. It may be on the rise due to increased use of gastric acid inhibitors
B. It is a colitis that is a superinfection
C. It is a major cause of diarrhea in hospitals
D. It is due to ingestion of contaminated, improperly stored, cooked meats and gravies
D. It is due to ingestion of contaminated, improperly stored, cooked meats and gravies
Streptococcal pharyngitis involves all of the following, except
A. it is usually caused by the viridans streptococci
B. it causes redness, difficulty in swallowing, and fever
C. it can lead to serious sequelae
D. it can lead to scarlet fever if it is an erythrogenic toxin-producing stain
A. it is usually caused by the viridans streptococci
The outcome of the Gram stain is based on differences in the bacterial cell’s
A. inclusions
B. ribosomes
C. cell membrane
D. cell wall
D. cell wall
All of the following structures contribute to the ability of pathogenic bacteria to cause disease, except
A. capsule
B. fimbriae
C. Gram-negative outer membrane
D. inclusions
D. inclusions
Which of the following is NOT correct about Streptococcus pyogenes?
A. It can cause impetigo and erysipelas
B. Some of the streptococcal toxins act as superantigens
C. Humans are the only significant reservoir
D. Most strains do not have a capsule
D. Most strains do not have a capsule
If bacteria living in salty seawater were displaced to a freshwater environment, the cell structure that would prevent the cells from rupturing is the
A. capsule
B. cell membrane
C. endospore
D. cell wall
D. cell wall
The periplasmic space is
A. made up of lipopolysaccharides and phospholipids
B. an important reaction site for substances entering and leaving the cell
C. absent in Gram-negative bacteria Present
D. just external to the LPS layer of the outer membrane
B. an important reaction site for substances entering and leaving the cell
A pregnant sex worker is told she has a positive CAMP test and should be treated with a course of antibiotics. This test is indicative of
A. Group A Streptococci
B. Group B Streptococci
C. S. saprophyticus
D. S. epidermidis
B. Group B Streptococci
Bacterial cells could have any of the following appendages, except
A. fimbriae
B. cilia
C. flagella
D. sex pili
C. flagella
Which of the following does NOT pertain to infant botulism?
A. Symptoms include flaccid paralysis and respiratory complications
B. Neurotoxin is not involved in the disease process
C. Symptoms include “floppy baby” appearance
D. Ingested spores can germinate in the immature
intestines of the neonate
B. Neurotoxin is not involved in the disease process
A 48-year-old man has had nasal surgery and absorbent material has been inserted into his nasal cavity to control bleeding. Several hours ago he began to complain of a headache and has since developed a red rash over much of his body and is experiencing muscle cramps and diarrhea. His blood pressure has dropped to 75/50 mm Hg. This patient’s illness is most likely caused by
A. Staphylococcus aureus – toxic shock syndrome
toxin
B. Streptococcus pyogenes – streptolysin O
C. Streptococcus pyogenes – erythrogenic toxin
D. Staphylococcus aureus – exfoliative toxin
A. Staphylococcus aureus – toxic shock syndrome toxin
A prokaryotic cell wall that is primarily composed of peptidoglycan with small amounts of teichoic acid and lipoteichoic acid is _______ and would most likely stain _______.
A. Gram-positive; blue
B. Gram-negative; red
C. Gram-negative; blue
D. Gram-positive; red
A. Gram-positive; blue
Necrotizing fasciitis is
A. typically a sequelae of streptococcal pharyngitis
B. possibly caused by antibodies to Group A streptococci that cross-react with body tissues
C. not treatable with antimicrobic drugs
D. associated with strains of Streptococcus producing destructive enzymes and toxins
D. associated with strains of Streptococcus producing destructive enzymes and toxins
Which structure protects bacteria from being phagocytized?
A. Slime layer
B. Capsule
C. Cell membrane
D. Fimbriae
B. Capsule
In bacteria such as members of the Bacillus and Clostridium genera, nutrient depletion is likely to result in
A. sporulation
B. binary fission
C. plasmolysis
D. germination
A. sporulation
Generally, what must healthy adults consume in order to contract botulism?
A. Vegetative cells of C. botulinum
B. Botulism toxin in contaminated food
C. Endospores of C. botulinum
D. Botulism toxoid in contaminated food
B. Botulism toxin in contaminated food
What do the bacteria that cause botulism, tetanus, and diphtheria have in common?
A. Each of these diseases is caused by an endospore-forming bacterial species
B. Each of these bacteria make an exotoxin that responsible for the disease
C. Each of these diseases is caused by oligately anaerobic bacteria
D. Vaccines are widely used to prevent each of these diseases
B. Each of these bacteria make an exotoxin that responsible for the disease
In which of the following situations would Staphylococcus epidermidis be the most likely etiologic agent?
A. Cystitis in patient with temporary insertion of urinary catheter
B. Septicemia in dialysis patient with intrajugular catheter
C. Diarrhea in patient with nasogastric tube
D. Ear infection in patient with hearing aid
B. Septicemia in dialysis patient with intrajugular catheter
A specimen was collected from a deep wound. A smear was prepared and Gram stained and samples were inoculated onto two blood agar plates. The Gram stain of the original specimen showed large Gram-positive bacilli. After inoculation, there was no growth on the blood agar plate that was incubated aerobically, but the plate incubated in the anaerobe jar grew beta hemolytic colonies. A Gram stain of these colonies showed large Gram positive bacilli, some with unstained
inclusions, suggestive of endospores. What is the most likely genus of bacteria observed?
A. Mycobacterium
B. Clostridium
C. Bacillus
D. Corynebacterium
B. Clostridium
A seasonal farmworker has been brought into the emergency room showing early symptoms of tetanus, including spastic contractions of face and neck muscles. His coworkers indicated that he had received a puncture wound in his hand a week prior to the onset of symptoms. His tetanus vaccination status is uncertain. Which of the following should be administered to the patient first, as soon as possible?
A. Tetanus toxoid
B. Tetanus titer
C. Tetanus immune globulin
D. Antibiotics
C. Tetanus immune globulin
Rebecca Lancefield differentiated streptococci on the basis of differences in their
A. Gram stain appearance
B. cell wall carbohydrates in a serological test
C. ability to produce catalase
D. patterns of hemolysis on blood sugar
B. cell wall carbohydrates in a serological test
Which of the following characteristics of living things is/are not found among viruses?
A. Cellular metabolism
B. Ability to evolve
C. Presence of nucleic acid
D. All of these characteristics are lacking viruses
A. Cellular metabolism
Which of the following is the infectious period of measles virus infection?
A. 5-7 days before rash to 3-5 days after the rash
B. 1-2 days before prodrome to 4 days after the onset of rash
C. 2 days before to 5 days after the onset of rash
D. 3 days before to 7 days after the onset of rash
B. 1-2 days before prodrome to 4 days after the onset of rash
Viruses cannot multiply unless it invades a host cell; therefore, they are considered
A. Automatic intracellular parasites
B. True intracellular parasites
C. Non-intracellular parasites
D. Obligate intracellular parasites
D. Obligate intracellular parasites
The correct sequence of events in viral multiplication is
A. adsorption, penetration, replication, assembly, maturation, release
B. assembly, maturation, replication, release, penetration, adsorption
C. replication, penetration, maturation, assembly, adsorption, release
D. penetration, replication, maturation, adsorption, assembly, release
A. adsorption, penetration, replication, assembly, maturation, release
Which of the following is the most common life threatening complication of measles
A. Measles encephalitis
B. Meningitis
C. Otitis media
D. Pneumonia
D. Pneumonia
. All of the following pertain to virus envelopes, EXCEPT
A. Are located between the capsid and nucleic acid
B. Help the virus particle attach to host cells
C. They are formed by the virus utilizing parts of the host cell membrane
D. They contain special virus proteins
A. Are located between the capsid and nucleic acid
Which of the following is an example of a B subfamily of herpes virinae?
A. Herpes simplex type 1
B. Cytomegalovirus
C. Epstein Barr virus
D. Varicella zoster virus
B. Cytomegalovirus
Corynebacterium diphtheria is made virulent by incorporated prophage genes encoding the diphtheria toxin. Which term describes this process?
A. Lysogenic conversion
B. Lytic phase
C. Adsorption
D. Latent phase
A. Lysogenic conversion
The nucleocapsid is composed of
A. the envelope and capsid
B. the capsomeres assembled into the capsid
C. the nucleic acid of the virus only
D. the nucleic acid along the capsid
D. the nucleic acid along the capsid
Which of the following statements is correct with regards to measles virus infection?
A. Measles virus begins with malaise, low grade fever, and a morbilliform rash appearing on the same day
B. Measles immune response are involved in disease pathogenesis
C. Typical measles is diagnosed based on identification of the virus from nasopharyngeal and conjunctival swabs
D. Measles virus is a member of the togavirus
B. Measles immune response are involved in disease pathogenesis
Susceptible individuals are those that belong to the extremes of age
A. The production of multiple copies of a virus by a host cell
B. The copying of the viral DNA in a DNA virus
C. The copying of the genomic RNA in an RNA virus
D. All of these choices are correct
D. All of these choices are correct
Helical and icosahedral are terms used to describe the shapes of a virus
A. Core
B. Envelope
C. Capsomere
D. Capsid
D. Capsid
A 75-year-old male, hypersensitive on Amlodipine 5 mg 1 tab once daily sought consult with his physician due to skin lesion on the left side of his back and chest, associated with itching and burning sensation. Condition was noted about 2 days PTC as onset of body malaise and undocumented fever. Patient had history of varicella infection during childhood. On examination there were grouped vesicles at the back and chest with erythematous base. Some lesions are beginning to get crushed. What will you give to this patient?
A. Acyclovir 800 mg/tab 1 tab 5x a day for 7 days
B. Vitamin A 50,000 IU single dose
C. No need to give medicine for this patient
D. Co-amoxiclav 625 mg 1 tab 2x a day for 7 days
A. Acyclovir 800 mg/tab 1 tab 5x a day for 7 days
Which of the following statements is more likely to be true of German measles (rubella) than measles (rubeola)?
A. Transient arthralgia and arthritis are commonly seen in adults, especially women
B. Koplik spots are present
C. The rash, starts on the head and then spreads
progressively to the chest, the trunk, and down the limbs, appears as light pink, discrete maculopapules that coalesce to form blotches, becoming brownish in 5-10 das
D. Prodromal phase is characterized by low to moderate grade fever, sneezing, coughing, running nose and conjunctivitis
A. Transient arthralgia and arthritis are commonly seen in adults, especially women
In general, most DNA viruses multiply in the host cell’s ________ while most RNA viruses multiply in the host cell’s _______.
A. cytoplasm; cell membrane
B. cell membrane; cytoplasm
C. nucleus; cytoplasm
D. cytoplasm; nucleus
C. nucleus; cytoplasm
Which of the following causes exanthema subitum (roseola infantum) as well as infectious in immunocompromised patients?
A. Rubella
B. HHV 7
C. HHV 6
D. Rubeola
C. HHV 6
Which of the following statements is correct regarding measles and rubella virus? (MULTIPLE ANSWERS)
A. Their virions contain an RNA polymerase
B. They have single antigenic type
C. They are RNA enveloped virus
D. They are transmitted by respiratory aerosol
B. They have single antigenic type
C. They are RNA enveloped virus
D. They are transmitted by respiratory aerosol
A 50-year-old frail-looking woman with a 10-year medical history of systemic lupus erythematosus for which she was given corticosteroid treatment came to your clinic due to fever, cough, dyspnea, and hemoptysis. A direct sputum examination done reveals hyaline, septate, and uniform width hyphae that branch dichotomously. Which of the following is most likely the cause of her current condition?
A. Bipolaris spp.
B. Aspergillus spp.
C. Mucor spp.
D. Candida albicans
B. Aspergillus spp.
The most common mycotic pulmonary infection is caused by which of the following?
A. Pneumocystis spp.
B. Aspergillus fumigatus
C. Rhizopus spp.
D. Histoplasma capsulatum
D. Histoplasma capsulatum
Which of the following fungal diseases are NOT caused by the so-called “black molds”?
A. Phaeohyphomycosis
B. Maduromycosis
C. Aspergillosis
D. Chromoblastomycosis
D. Chromoblastomycosis
What laboratory dermatophyte identification method will show a long narrow septated and branching hyphase in dermatophytosis?
A. Periodic acid-Schiff
B. Potassium hydroxide preparation
C. Dermatophyte test medium
D. Culture
B. Potassium hydroxide preparation
Fungal cells that reproduce by budding are seen in the infected tissues of patients with which of the following diseases?
A. Mycetoma, candidiasis, and mucormycosis
B. Candidiasis, cryptococcosis, and sprorotrichosis
C. Tinea corporis, tinea unguium, and tinea versicolor
D. Sprorotrichosis, mycetoma, and aspergillosis
B. Candidiasis, cryptococcosis, and sprorotrichosis
A 60-year-old obese woman with long standing uncontrolled diabetes mellitus began to manifest swelling in the glabella associated with dark brown to black discoloration. As a resident physician in ENT training you called the attention of your consultant who considered rhinocerebral mucormycosis and insisted to have a direct examination of the nasal discharge ASAP. Which of the following findings would support the above diagnosis?
A. Formation of pseudohyphae and cell budding
B. Hyphae with production of blastoconidia
C. Appearance of hyphae with uniform width, regular cross walls and bifurcations
D. Presence of sparsely septated hyphae of uneven thickness and irregular branching
D. Presence of sparsely septated hyphae of uneven thickness and irregular branching
Which of the following statements associated with cutaneous mycoses are CORRECT?
A. Clinical forms are based on site of involvement
B. Lesions are somewhat worse with anthropophilic fungi as they produce the most number of irritants
C. The choice location to obtain specimen for diagnosis is at the center of the lesion where hyphal growth is the most robust
D. Zoophilic dermatophytes are easiest to identify because they produce the most number of conidia
A. Clinical forms are based on site of involvement
A 28-year-old florist had her finger pricked while pruning rose bushes. This leads to formation of localized pustule that became an ulcerated lesion. Few days later, nodules began to appear in her wrist and proximal arm. Tissue biopsy would most likely reveal which of the following?
A. Granulomatous formation
B. Presence of asteroid body
C. Fusiform yeast cells
D. All of the above
D. All of the above
A 10-year-old child undergoing chemotherapy for acute leukemia began to complain about recurring headaches, stiff neck, and disorientation. SF taken from a lumbar puncture reveal presence of encapsulated unicellular yeast cells on negative staining. The causative agent is best classified as a
A. deuteromycete
B. ascomycete
C. basidiomycete
D. zygomycete
C. basidiomycete
All of the following statements regarding Pneumocystis jiroveci are correct EXCEPT
A. no known reservoir is demonstrated
B. it does not cause disease in the absence of immunosuppression
C. itraconazole is the drug of choice
D. the cyst form is the infective stage
C. itraconazole is the drug of choice
- Case: ENT referral of 57-year old male.
Complaints: Sudden onset of fever, hypotension, tachycardia, no urine output, and a sunburn-like rash.
History: Patient went to the ENT 3 days ago for epistaxis and was managed with a nasal pack. The patient went home against doctor’s advice.
On examination, nasal packs still inside nostrils.
Laboratory results: Elevated liver enzymes and elevated creatinine.
Question: What toxin is primarily involved in this disease spectrum?
A. ET B
B. Spe A
C. TSST-1
D. ET A
C. TSST-1
This virulence factor is considered important and, in fact, is the first requirement for successful infection of a host:
A. Invasion factors
B. Adherence factors
C. Antigenic heterogeneity
D. Antiphagocytic factors
B. Adherence factors
Case: 56-year old diabetic female
Complaints: Fever, chills, and redness and swelling of her left posterior leg.
PE: Affected site appears edematous, with an erythematous, raised lesion with sharp distinct edges between the affected area and unaffected skin. It was warm and tender to touch.
Question: What is the most likely etiologic agent?
A. Streptococcus agalactiae
B. Streptococcus pneumoniae
C. Streptococcus pyogenes
D. Staphylococcus aureus
C. Streptococcus pyogenes
What is the drug of choice for B. anthracis treatment?
A. Cephalexin
B. Cotrimoxazole
C. Clindamycin
D. Ciprofloxacin
D. Ciprofloxacin
Which of the following show “cut glass” appearance on culture?
A. Clostridium
B. Corynebacterium
C. Bacillus
D. Mycobacterium
C. Bacillus
You find a microscopic slide from a patient’s specimen that contains S. mutans. The specimen is most likely:
A. Pus from patient’s acne
B. Patient’s vaginal secretions
C. Plaque from patient’s tooth
D. Patient’s stool
C. Plaque from patient’s tooth
Which of the following antibiotics can be used to suppress the toxin-producing bacteria causing
pharyngeal pseudomembranous disease?
A. Macrolides
B. Cephalosporins
C. Antifungals
D. Aminoglycosides
A. Macrolides
Which of the following body fluids is NOT generally considered sterile?
A. Tears
B. Gall bladder bile
C. Urinary bladder urine
D. Blood
A. Tears
Which of the following media allows growth of gram-positive cocci only?
A. CNA blood agar
B. Blood agar
C. MacConkey agar
D. Chocolate agar
A. CNA blood agar
What causes the “bull neck” appearance in patients with diphtheria?
A. Enlargement of lymph nodes
B. Destruction of neck epithelium
C. Necrosis of throat epithelium
D. Edema of mediastinum
A. Enlargement of lymph nodes
These refer to microorganisms that are regularly found in a given area at a given age, and promptly
reestablish themselves if disturbed:
A. Transient microbiota
B. Resident microbiota
C. Pathogenic microbiota
D. Opportunistic microbiota
B. Resident microbiota
It is during this phase of bacterial growth that sporulation of bacteria occur:
A. Stationary
B. Log
C. Lag
D. Death
A. Stationary
Which of the following statements concerning the staining of bacteria is correct?
A. Mycoplasma pneumoniae is not visible using Gram’s stain
B. Gram negative bacteria stains pink because it has a thick peptidoglycan layer
C. Capsules are stained best with safranin
D. Acid fast bacteria stains pink because it has a thick lipid layer
A. Mycoplasma pneumoniae is not visible using Gram’s stain