Microbiology Flashcards
Essential components of bacteria, EXCEPT:
A. Cell wall B. Ribosome C. Nuceloid D. Mesosome E. Capsule
E. Capsule
ESSENTIAL:
- cell wall
- cytoplasmic membrane
- ribosome
- nucleoid
- mesosome
- periplasm
NON-ESSENTIAL:
- capsule
- pilius or fimbrium
- glycocalyx
- flagellum
- spore
- plasmid
- granule
Non-cellular infectious proteins resistant to nucleases, proteases and normal autoclaving
A. Viruses B. Bacteria C. Viroids D. Prions E. None of the above
D. Prions
The following can cause infections in humans, EXCEPT:
A. Bacteria B. Viruses C. Viroids D. Prions E. None of the above
C. Viroids
Viroids are obligate intracellular parasites of PLANTS and are not known to cause any human disease.
True of Gram-positive bacteria:
A. Thicker peptidoglycan layer B. Presence of teichoic acids C. Does not contain Lipopolysaccharide D. No periplasmic space E. All of the above
E. All of the above
Gram-negative bacteria:
- thinner peptidoglycan layer
- lipopolysaccharide (endotoxin)
- periplasmic space
- no teichoic acids
Bacteria with a capsule composed of polypeptide.
A. Bacillus anthracis B. Bacillus cereus C. Clostridium tetani D. Listeria monocytogenes E. Both A and B
A. Bacillus anthracis
All bacterial capsules are composed of polysaccharride except B. anthracis.
A 72 year old male admitted at the wards, with a known history of BPH, developed fever and leukocytosis. Presence of a biofilm was noted on the patient’s catheter, what is the most likely organism?
A. Streptococcus pyogenes B. Streptococcusviridans C. Staphylococcus saprophyticus D. Staphylococcus epidermidis E. Stapylococcus aureus
D. Staphylococcus epidermidis
S. epidermidis is noted for its ability to form biofilms which adhere to intravenous lines, prosthetic joints, ventriculoperitoneal shunts and indwelling catheters.
Which of the following describes the organism involved in the case discussed in the previous question?
A. Catalase-negative, α-hemolytic, bacitracin- sensitive
B. Catalase-negative, α-hemolytic, bile-optochin-resistant
C. Catalase-positive, coagulase-negative, novobiocin-resistant
D. Catalase-positive, coagulase-negative, novobiocin-sensitive
E. Catalase-positive, coagulase-positive
D. Catalase-positive, coagulase-negative, novobiocin-sensitive
A - Streptococcus pyogenes B - Streptococcus viridans C - Staphylococcus saprohyticus D - Staphylococcus epidermidid E - Staphylococcus aureus
A 32 year old male who is an overseas worker, arrived at the ER presenting with sudden onset of high fever, chills and myalgias, on physical examination a murmur was heard at the left lower sternal border, multiple puncture marks were also noted on the right and left cubital fossa. Patient later confessed to using heroin. What is most likely organism involved?
A. Catalase-negative, α-hemolytic, bacitracin- sensitive
B. Catalase-negative, α-hemolytic, bile-optochin-resistant
C. Catalase-positive, coagulase-negative, novobiocin-resistant
D. Catalase-positive, coagulase-negative, novobiocin-sensitive
E. Catalase-positive, coagulase-positive
E. Catalase-positive, coagulase-positive
The patient in the case discussed is most likely experiencing acute endocarditis, caused by S. aureus. It is associated to tricuspid valve insufficiency and IV drug use.
A 17 year old female living in a dormitory, arrived at the ER, presenting with fever, headache and stiff neck, spinal fluid revealed increase level of PMNs. What is the drug of choice ?
A. Penicillin G B. Ceftriaxone C. Ampicillin D. Erythromycin E. Rifampin
A. Penicillin G
Most common cause of meningitis among those aged 2-18 years old is N. meningitides, associated with high carriage rates in close quarters like military camps and dormitories.
What should be given as prophylaxis to the dorm mates of the patient discussed in the previous question?
A. Penicillin G B. Cefuroxime C. Doxycycline D. Erythromycin E. Rifampiin
E. Rifampin
RIFAMPIN - chemoprophylaxis of choice against N. meningitides
Granulomatosis infantiseptica is caused by:
A. Streptococcus agalactiae B. Escherichia coli C. Listeria monocytogenes D. Haemophilus influenzae E. Streptococcus pneumoniae
C. Listeria monocytogenes
Usually transmitted tranplacentally, characterized by late miscarriage or birth complicated by sepsis, multiorgan abscesses and disseminated granulomas.
Urease-postitive bacteria:
A. Proteus mirabilis B. Klebsiella pneumoniae C. Helicobacter pylori D. Only A and C E. All of the above
E. All of the above
Urease-positive:
- Proteus mirabilis
- Klebsiella pneumoniae
- Helicobacter pylori
- Ureaplasma urealyticum
The following are negative-sense RNA viruses, EXCEPT:
A. Paramyxoviridae B. Orthomyxoviridae C. Filoviridae D. Flaviviridae E. Rhabdoviridae
D. Flaviviridae
Negative-sense RNA viruses:
- Arenaviridae
- Bunyaviridae
- Paramyxoviridae
- Orthomyxoviridae
- Filoviridae
- Rhabdoviridae
5 year old male presented with a centrifugal rash 2 weeks after a respiratory infection, rash was noted to have a “dewdrop on arose appearance”. The disease is most likely caused by a:
A. DNA virus that is double-stranded and enveloped
B. DNA virus that is double-stranded and naked
C. DNA virus that is single-stranded and naked
D. RNA virus that is single-stranded, enveloped and helical.
E. RNA virus that is double-stranded and naked
A. DNA virus that is double-stranded and enveloped
Varicella zoster is part of Herpeviridae, together with HSV 1, HSV 2, EBV, CMV, HHV-6, and HHV-8.
Which of the following is/are true about Cytomegalovirus
A. Causes heterophil-negative mononucleosis
B. Most common cause of congenital abnormalities
C. Affects immunocompromised patients
D. Only B and C
E. All of the above
E. All of the above
CMV = heterophil-NEGATIVE mononucleosis
Toxoplasma gondii = heterophil-NEGATIVE mononucleosis
EBV = heterophil-POSITIVE mononucleosis
The following infection is associated with the autoimmune vaculitides, polyarteritis nodosa.
A. Hepatitis A B. Hepatitis B C. Hepatitis C D. HIV E. EBV
B. Hepatitis B
Hep B is associated with PAN.
Which of the following describes Cryptococcos neoformans
A. Polysaccharide encapsulated yeast, presents with a surrounding halo in India ink stain
B. Non-encapsulated dimorphic fungus, usually found in bird and bat droppings
C. May appear as oval yeast with a single bud or as pseudohyphae
D. Thick yeast with multiple buds in wheel configuration “mariner’s wheel”
E. All of the above
A. Polysaccharide encapsulated yeast, presents with a surrounding halo in India ink stain
A 62 year old woman presented with head, fever,drowsiness and confusion, CT-scan revealed ring-enhancing lesions. Further investigation revealed that she lives alone, and owns several cats. What is the drug of choice for the patient’s likely condition?
A. Melarsoprol B. Pentamidine C. Sulfadiazine + Pyrimethamine D. Sodium stibogluconate E. Nifurtimox
C. Sulfadiazine + Pyrimethamine
Toxoplasma gondii = definitive host- the domestic cat, infective stage- fecal oocyst
Spectrum of disease includes heterophil-negative mononucleosis, encephalitis, and congenital toxoplasmosis.
Treament of choice is sulfadiazine + pyrimethamine.
7 year old male was brought to the clinic by her mother due to complaints of itching and frequent scratching of his anus. The parasite most likely is involved is usually diagnosed by?
A. Harada mori culture B. Kato-Katz technique C. Direct fecal smear D. Graham scotch tape technique E. Both B and C
D. Graham scotch tape technique
Enterobius vermicularis may present with pruritus ani, diagnosis is by graham scotch tape technique, drug of choice is pyrantel pamoate.
he following are nematodes, EXCEPT:
A. Ascaris lumbricoides B. Trichuris trichiura C. Enterobius vermicularis D. Strongyloides stercoralis E. Diphylobotrium latum
E. Diphylobotrium latum
Diphylobotrium latum is a cestode, together with Taenia spp. and Echinocoocus granulosus.
