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Microbiologie​ Preparation (Dr. Aim Sothea​)

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1) A 55-year-old man came to IPD complaining of weakness, malaise, and cough. He has history of
smoking and social drinking. General condition upon admission was moderate: axillar temperature of
38 °C, respiratory rate of 21/min, SpO2 of 92%, heart rate at 90 beats/min, and blood pressure of
130/70 mm Hg. Bilateral pneumonia was suspected on chest-x ray. Culture of sputum showed
coagulase positive, Gram positive cocci. Which of the following microorganism causes for this
condition?

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2) A 6-year-old boy developed an erythematous rash around his face and arms. Swollen lymph nodes around the infection were reported on the physical examination but no other abnormality. A gram- positive and coagulase positive cocci were identified. What is most likely pathogen for above condition?

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3) Streptococcus viridans can be differentiated from other haemolytic Streptococci on the basis of
its resistance to

4 / 52

4) 60-man is hospitalized for pneumonia and urine catheter is placed. Patient feels better after 2
days, however he has dysuria and urgency. A urine culture reveals gramm+ in pairs and chain.
Antibiogram is resistant to vancomycin. What is true about the pathogen?

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5) What is major virulence factor for Streptococcus pneumoniae uses to evade the host’s immune
response?

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6) A 17-year female was admitted complaining about a fever of 39.3oC and vomiting. She started
her menstrual period 4 days before she became ill. On the next day of admission, she had continued
fever, vomiting and loose stools. She was hypotensive of SBP of 78 & DBP 54 mmHg with a heart
rate of 120 beats per min. Physical exam found most prominent erythematous rash on her trunk.
Cultures were obtained from vaginal specimen show catalase positive, Gram positive cocci of
staphylococcus colonies. Which cytokines are responsible for systemic shock syndrome?

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7) During one week, a 7-year boy develops pustules on his face. Then, some of the pustules break,
forming shallow erosions in appearance of a honey-colored crust. Next, new lesions form around the
crust. The boy’s¬ father has similar lesions after one week of the son’s illness. The Gram stain from a
skin pustule showed gram positive in grape-like clusters. The colonies were catalase positive. What
is the most likely microorganism?

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8) Before dental procedure Ampicillin is given to prevent bacterial sub-acute endocarditis in high-
risk person. What is most likely pathogen for this condition?

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9) A 19-y sexually active woman came to OPD having dysuria and pain when urinating. Urine
culture reveals Gram positive, Coagulase negative and novobiocin negative cocci. What pathogen is
most likely causing the presenting problem?

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10) Staphylococcus spp. and Streptococcus spp. are

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11) A 39-y patient is on Central Venous Perfusion line in an ICU. Culture around the line grows
Gramm positive, Coagulase negative cocci in cluster. Which of the following is most likely pathogen
for the above description?

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12) A 25-y woman came to ER having 5-hour of fever, rash, and altered mental status. Her BP is low (76/58) and HR is fast. After physical exam, a used tampon is removed from genital tract. Culture of vaginal and nasal specimen reveals Gram positive in cluster. What most likely mechanism is responsible for problem?

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13) A 25-y woman came to ER having 5-hour of fever, rash, and altered mental status. Her BP is low (76/58) and HR is fast. After physical exam, a used tampon is removed from genital tract. Culture ofvaginal and nasal specimen reveals Gram positive in cluster. What factor is responsible for systemic shock syndrome?

14 / 52

14) A 6-year-old boy presents to his pediatrician for sore throat and a headache. His symptoms
began approximately 2 days ago and have not improved. The boy appears uncomfortable and feels
warm. Physical examination is notable for perioral crusted lesions with tonsillar swelling with
exudates. Pharyngeal swap reveals gram positive cocci, with catalase negative and bacitracin
sensitive. Which Lancefield group the pathogen belongs?

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15) A 35-y patient was put on Central Venous Perfusion (CVP) line in an Intensive Care Unit (ICU)
for 10 days. Culture grows staph epidermidis. What is appropriate description about staph
epidermidis?

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16) Part of the success of the Streptococcus pyogenes bacterium lies in its ability to evade
phagocytosis. Which of the following helps in this evasion?

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17) A 6-year-old boy presents to his pediatrician for sore throat and a headache. His symptoms
began approximately 2 days ago and have not improved. The boy appears uncomfortable and feels
warm. Physical examination is notable for perioral crusted lesions with tonsillar swelling with
exudates. Pharyngeal swap reveals gram positive cocci, with catalase negative and bacitracin
sensitive. Which of the following pathogens is causing the problem?

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18) Which of the following bacteria is also called the gamma or nonhemolytic streptococci?

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19) Within hours of food consumption, 45 year old man experienced acute gastroenteritis was admitted to the ICU. The patient progressed on to develop system shock. Culture of stool was positive for Staphylococcus aureus. What factor is responsible for acute gastroenteritis?

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20) A 25-y woman came to ER having 5-hour of fever, rash, and altered mental status. Her BP is low (76/58) and HR is fast. Nasal specimen reveals Gramm positive in cluster with positive test for coagulase. What is most likely organism responsible for problem?

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21) Which test to be conducted to differentiate between Staph epidermidis and Staph saprophyticus?

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22) A 65-old man transferred to ER having sudden nausea vomiting & confusion. Physical exam:
high fever 38.8C, Brudzinski positive and altered mental status. CSF Gramm stain reveals gramm+
lancet-shape diplococci. What pathogen is most likely pathogen responsible for the patient problem?

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23) Which of the following cocci is found in the mouth as normal flora?

24 / 52

24) The bacteria involved in the production of dental caries is

25 / 52

25) Which of bacteria having property of catalase positive, coagulase negative and Novobiocin sensitive?

26 / 52

26) A 19-y sexually active woman came to OPD having dysuria and pain when urinating. Urine
culture reveals Gram positive, catalase positive cocci. Which two lab tests would be most helpful to
distinguish the causal organism from other members?

27 / 52

27) A 6-year-old boy presents to his pediatrician for sore throat and a headache. His symptoms
began approximately 2 days ago and have not improved. The boy appears uncomfortable and feels
warm. Physical examination is notable for perioral crusted lesions with tonsillar swelling with
exudates. Pharyngeal swap reveals Strep pyogenes as causal agent. Which of the following is true
about the pathogen?

28 / 52

28) A 39-y patient is on Central Venous Perfusion line in an ICU. Culture around the line grows
staph epidermidis. What is pathogenesis mechanism for this pathogen?

29 / 52

29) A 19-y sexually active woman came to OPD having dysuria and pain when urinating. Urine
culture reveals staph saprophyticus. Which is urease test result for this pathogen?

30 / 52

30) 60-man is hospitalized for pneumonia and urine catheter is placed. Patient feels better after 2
days, however he has dysuria and urgency. A urine culture reveals gramm+ in pairs and chain.
Antibiogram is resistant to vancomycin.What is most likely pathogen for this condition?

31 / 52

31) A 39-y patient is on Central Venous Perfusion line in an ICU. Culture around the line grows
Gramm positive, Coagulase negative cocci in cluster. What the pathogen most likely reacts with
Novobiocin test?

32 / 52

32) A 4-year boy was admitted establish the diagnosis of a generalized skin rash and fever. The
family histories were not known because the boy was in care center from age of 2 months. The boy
experienced frequent upper respiratory infections and tonsillitis. Diffused epidermal exfoliation from
the face, thorax, members, and scalp were observed. What is most likely diagnosis for above
condition?

33 / 52

33) A 17-year female was admitted complaining about a fever of 39.3oC and vomiting. She started
her menstrual period 4 days before she became ill. Physical exam found most prominent
erythematous rash on her trunk. Vaginal specimen shows catalase positive, Gram positive cocci. The
patient was given intravenous fluids and IV antibiotics and transported to the hospital. Which of the
following microorganism causes the condition?

34 / 52

34) A 10-year-old male is taken to his physician by his parents due to a sore throat. The bacteria
from throat specimen are gram-positive and bacitracin inhibits their growth. The child is given
treatment of Penicillin G and sent home. Which of the following is most likely cause the problem?

35 / 52

35) A 10-year-old male is taken to his physician by his parents due to a sore throat. The bacteria
from throat specimen are gram-positive and bacitracin inhibits their growth. The child is given
treatment of Penicillin G and sent home. 20 years later, the patient presents to the emergency
department with dyspnea on exertion and CXR showed an enlarged cardiac silhouette and
pulmonary edema. The patient’s current symptomatology most likely occurred secondary to which of
the following?

36 / 52

36) A 17-year female was admitted complaining about a fever of 39.3oC and vomiting. She started
her menstrual period 4 days before she became ill. On the next day of admission, she had continued
fever, vomiting and loose stools. She was hypotensive of SBP of 78 & DBP 54 mmHg with a heart
rate of 120 beats per min. Physical exam found most prominent erythematous rash on her trunk.
Cultures were obtained from vaginal specimen show catalase positive, Gram positive cocci of
staphylococcus colonies. Which pathogen is responsible the stated problem?

37 / 52

37) A 4-year boy was admitted establish the diagnosis of a generalized skin rash and fever. The
family histories were not known because the boy was in care center from age of 2 months. The boy
experienced frequent upper respiratory infections and tonsillitis. Diffused epidermal exfoliation from
the face, thorax, members, and scalp were observed. What is most likely pathogen for above
condition?

38 / 52

38) A 17-year female was admitted complaining about a fever of 39.3oC and vomiting. She started
her menstrual period 4 days before she became ill. On the next day of admission, she had continued
fever, vomiting and loose stools. She was hypotensive of SBP of 78 & DBP 54 mmHg with a heart
rate of 120 beats per min. Physical exam found most prominent erythematous rash on her trunk.
Cultures were obtained from vaginal specimen show catalase positive, Gram positive cocci. The
patient was given intravenous fluids and IV antibiotics and transported to the hospital. Which
pathogen causes the systemic syndrome?

39 / 52

39) Which of the following bacteria have been found to be most resistant to the drug vancomycin?

40 / 52

40) A 17-year female was admitted complaining about a fever of 39.3oC and vomiting. She started
her menstrual period 4 days before she became ill. On the next day of admission, she had continued
fever, vomiting and loose stools. She was hypotensive of SBP of 78 & DBP 54 mmHg with a heart
rate of 120 beats per min. Physical exam found most prominent erythematous rash on her trunk.
Cultures were obtained from vaginal specimen show catalase positive, Gram positive cocci of
staphylococcus colonies. Which action of the factors is explained for systemic shock syndrome?

41 / 52

41) A 4-year boy was admitted establish the diagnosis of a generalized skin rash and fever. The
family histories were not known because the boy was in care center from age of 2 months. The boy
experienced frequent upper respiratory infections and tonsillitis. Diffused epidermal exfoliation from
the face, thorax, members, and scalp were observed. Culture of injured skin was positive for
Staphylococcus aureus. What factor is responsible for the problem?

42 / 52

42) What pathogen causing indwelling device-associated infection?

43 / 52

43) A 55-year-old man came to IPD complaining of weakness, malaise, and cough. He has history of
smoking and social drinking. General condition upon admission was moderate: axillar temperature of
38 °C, respiratory rate of 21/min, SpO2 of 92%, heart rate at 90 beats/min, and blood pressure of
130/70 mm Hg. Bilateral pneumonia was suspected on chest-x ray. Culture of sputum showed
coagulase positive, Gram positive cocci. What factor is responsible for the problem?

44 / 52

44) A 14-year-old male is brought to the Emergency Department by his mother. She is worried
because his face has become puffy and his urine has turned a tea-color. Patient history reveals the
child recently suffered from a sore throat. The physician suspects a bacterial infection. Which of the
following describes the likely bacterium responsible?

45 / 52

45) What is the most common type of infection caused by Streptococcus pneumoniae?

46 / 52

46) Which biochemical test to distinguish between Staph epidermidis and Staph areus?

47 / 52

47) A 17-year female was admitted complaining about a fever of 39.3oC and vomiting. She started
her menstrual period 4 days before she became ill. Physical exam found most prominent
erythematous rash on her trunk. Vaginal specimen revealed Staphylococcus aureus. The patient was
given intravenous fluids and IV antibiotics and transported to the hospital. Which is true about the
pathogen?

48 / 52

48) A 6-year-old boy presents to his pediatrician for sore throat and a headache. His symptoms
began approximately 2 days ago and have not improved. The boy appears uncomfortable and feels
warm. Physical examination is notable for perioral crusted lesions with tonsillar swelling with
exudates. Pharyngeal swap reveals gram positive cocci, with catalase negative and bacitracin
sensitive. Which group of hemolysis the pathogen belong?

49 / 52

49) A 65-old man transferred to ER having sudden nausea vomiting & confusion. Physical exam:
high fever 38.8C, Brudzinski positive and altered mental status. CSF Gramm stain reveals gramm+
lancet-shape diplococci. Which of the following is true about the pathogen?

50 / 52

50) A 6-year-old boy presents to his pediatrician for sore throat and a headache. His symptoms
began approximately 2 days ago and have not improved. The boy appears uncomfortable and feels
warm. Physical examination is notable for perioral crusted lesions with tonsillar swelling with
exudates. Which of the following is most likely cause the problem?

51 / 52

51) What are property of Staph aureus ?

52 / 52

52) A 6-year-old boy presents to his pediatrician for sore throat and a headache. His symptoms
began approximately 2 days ago and have not improved. The boy appears uncomfortable and feels
warm. Physical examination is notable for perioral crusted lesions with tonsillar swelling with
exudates. Pharyngeal swap reveals gram positive cocci, with catalase negative and bacitracin
sensitive. What is most likely diagnosis?

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