Question Thread - Choose the Best Answer

DrIreland · 15-02-06, 18:18

A 24 year old women has fever, malaise, and a dry, nonproductive cough. She also complains of headache, muscle aches, and leg pain. Lab values are significant for elevated cold agglutinins. Which of the following microorganisms is responsible for her symptoms:

A Haemophilus influenza
B Klebsiella pneumonia
C Legionella pneumophilia
D Mycoplasma pnemonia
E Streptococcus pneumonia

Pversicolor · 16-02-06, 07:17

Hmmm...this one was tough for me.

I first broke the answer down to H. influenza, M. pneumonia, and K. pneumonia as they are the common causes of atypical pneumonia. L. pneumophilia was thrown out as she's not elderly or has a history of travel. S. pneumonia was thrown out because the presentation seems atypical (myalgia, npcough).

I don't know what the cold agglutinins stand for, could someone give a little tutorial on this?

My choice - H. influenza on a hunch.

DrIreland · 16-02-06, 09:13

Hi versicolor -

The answer here is M. pneumonia, a bacterium that causes pneumonia in young adults and elevated cold agglutinins (IgM) are the classic clue found in hald the patients.

H influenza causes a bronchopneumonia in infants and children

Klebsiella pneumonia occurs in debiliated patients, alcoholics, and diabetics and has the characteristic red currant jelly sputum.

S pneumoniae is most common in elderly or those with poor nutrition.

Legionella pneumophilia like you said is common in elderly from water sources (a/c, showers, etc)

A bit on agglutinins:
Warm – IgG AB that lyse RBCs by 2 mech – immune adherence of RBC to phagocytes mediated by antibody and complement and complement activation.
Cold – IgM cold reactive antibodies arise in two settings: monoclonal AB product of lymphocytic neoplasia or paraneoplasia and 2 polyclonal AB in response to infection, classically in Mycoplasma pneumonia

DrIreland · 16-02-06, 09:35

This one is without choices but try to respond to the questions, they are high yeild for the subject!

Febrile young person with rapid onset of stiff neck, mental confusoin, and skin petechiae, causative agent? What surface component enables CA to reach the blood brain barrier? What enables it to cross the BBB? Which serotype is least immunogenic? Is it contagious?

Mfurfur · 19-02-06, 21:25

Causative agent: Neisseria meningitidis most likely.

Surface components: Polysaccharide capsule (protection) and enable to reach BBB. Endotoxin in outer membrane promtoes inflammation and facilitates invasion of CNS.

Least immunogenic serotype: B capsule composed of sialenacid, not immunogenic.

Contagiousness: epidemic disease, many more colonised than develop disease.

Mfurfur · 19-02-06, 21:34

A 54-year-old woman suffering from influenza deteriorates and develops shaking chills and a high fever. Physical examination is remarkable for dullness to percussion at the left base and decreased breath sounds on the left. Chest x-ray confirms the diagnosis of lobar pneumonia, presumed to be caused by Streptococcus pneumoniae. The patient has no known drug allergies. Which of the following antibiotics would be most appropriate to treat the patient's condition?

A. Cefotaxime

B. Chloramphenicol

C. Erythromycin

D. Penicillin

E. Vancomycin

15-02-06, 18:18	#1
DrIreland Erik Administrator Join Date: Jan 2006 Posts: 168	Question Thread - Choose the Best Answer A 24 year old women has fever, malaise, and a dry, nonproductive cough. She also complains of headache, muscle aches, and leg pain. Lab values are significant for elevated cold agglutinins. Which of the following microorganisms is responsible for her symptoms: A Haemophilus influenza B Klebsiella pneumonia C Legionella pneumophilia D Mycoplasma pnemonia E Streptococcus pneumonia
OFF CALL

16-02-06, 07:17	#2
Pversicolor Junior Member Join Date: Jan 2006 Posts: 25	Hmmm...this one was tough for me. I first broke the answer down to H. influenza, M. pneumonia, and K. pneumonia as they are the common causes of atypical pneumonia. L. pneumophilia was thrown out as she's not elderly or has a history of travel. S. pneumonia was thrown out because the presentation seems atypical (myalgia, npcough). I don't know what the cold agglutinins stand for, could someone give a little tutorial on this? My choice - H. influenza on a hunch.
OFF CALL

16-02-06, 09:13	#3
DrIreland Erik Administrator Join Date: Jan 2006 Posts: 168	Hi versicolor - The answer here is M. pneumonia, a bacterium that causes pneumonia in young adults and elevated cold agglutinins (IgM) are the classic clue found in hald the patients. H influenza causes a bronchopneumonia in infants and children Klebsiella pneumonia occurs in debiliated patients, alcoholics, and diabetics and has the characteristic red currant jelly sputum. S pneumoniae is most common in elderly or those with poor nutrition. Legionella pneumophilia like you said is common in elderly from water sources (a/c, showers, etc) A bit on agglutinins: Warm – IgG AB that lyse RBCs by 2 mech – immune adherence of RBC to phagocytes mediated by antibody and complement and complement activation. Cold – IgM cold reactive antibodies arise in two settings: monoclonal AB product of lymphocytic neoplasia or paraneoplasia and 2 polyclonal AB in response to infection, classically in Mycoplasma pneumonia
OFF CALL

16-02-06, 09:35	#4
DrIreland Erik Administrator Join Date: Jan 2006 Posts: 168	This one is without choices but try to respond to the questions, they are high yeild for the subject! Febrile young person with rapid onset of stiff neck, mental confusoin, and skin petechiae, causative agent? What surface component enables CA to reach the blood brain barrier? What enables it to cross the BBB? Which serotype is least immunogenic? Is it contagious?
OFF CALL

19-02-06, 21:25	#5
Mfurfur Member Join Date: Jan 2006 Posts: 55	Causative agent: Neisseria meningitidis most likely. Surface components: Polysaccharide capsule (protection) and enable to reach BBB. Endotoxin in outer membrane promtoes inflammation and facilitates invasion of CNS. Least immunogenic serotype: B capsule composed of sialenacid, not immunogenic. Contagiousness: epidemic disease, many more colonised than develop disease.
OFF CALL

19-02-06, 21:34	#6
Mfurfur Member Join Date: Jan 2006 Posts: 55	A 54-year-old woman suffering from influenza deteriorates and develops shaking chills and a high fever. Physical examination is remarkable for dullness to percussion at the left base and decreased breath sounds on the left. Chest x-ray confirms the diagnosis of lobar pneumonia, presumed to be caused by Streptococcus pneumoniae. The patient has no known drug allergies. Which of the following antibiotics would be most appropriate to treat the patient's condition? A. Cefotaxime B. Chloramphenicol C. Erythromycin D. Penicillin E. Vancomycin
OFF CALL