Bugs for Step 1

[MudPhud20XX]

the same for bugs....

the most common cause of osteomyelitis in sickle cell pts?

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[Apoplexy__]

I'll throw in a couple good ones to know too. Name the microbe:
1. Aplastic anemia in sickle cell?
2. Hyponatremia + pneumonia?
3. Endocarditis after cystoscopy?

 

[The Sports Doc]

Salmonella

the same for bugs....

the most common cause of osteomyelitis in sickle cell pts?

 

[MudPhud20XX]

Salmonella

correct.

 

[faisal 2000]

which organisms can cause chronic granulomatous disease ?

 

[MudPhud20XX]

which organisms can cause chronic granulomatous disease ?

most intracellular bugs and TB right?

 

[MudPhud20XX]

I'll throw in a couple good ones to know too. Name the microbe:
1. Aplastic anemia in sickle cell?
2. Hyponatremia + pneumonia?
3. Endocarditis after cystoscopy?

Kirby, I have no clue. Please help us out.

 

[MudPhud20XX]

A 7-year-old girl presented to the emergency room (ER) of a hospital in Oklahoma with fever, nausea, malaise, abdominal pain, and vomiting. She was diagnosed with viral gastroenteritis and released. Four days later, she was brought into another ER. In addition to the previous symptoms, she had cough, myalgias, and a measles-like petechial rash that began on the palms and soles and spread to the arms, legs, and trunk. She had marked leukocytosis. An immunofluorescent assay showed immunoglobulin G (IgG) antibodies reactive with the suspected pathogen. There was no history of a recent tick bite, but it was reported the family dogs often had ticks which were removed by members of the household. What was the most likely cause?

 

[faisal 2000]

most intracellular bugs and TB right?

chronic granulomatous disease -poor o2 dependent killing so organisms will cause this which produce catalase :
1-s.aureus 2-p.cepasia 3-nocardia 4-aspergillus

 

[mcloaf]

I'll throw in a couple good ones to know too. Name the microbe:
1. Aplastic anemia in sickle cell?
2. Hyponatremia + pneumonia?
3. Endocarditis after cystoscopy?

1. Parvovirus B19
2. Legionnaire's disease
3. ...Enterococcus?

which organisms can cause chronic granulomatous disease ?

I haven't done enough qbank questions to know what the classically tested ones are, but there is the SPANS KEC mnemonic for catalase positive bugs (Staph, pseudomonas, aspergillus, nocardia, serratia, klebsiella, e. coli, candida).

A 7-year-old girl presented to the emergency room (ER) of a hospital in Oklahoma with fever, nausea, malaise, abdominal pain, and vomiting. She was diagnosed with viral gastroenteritis and released. Four days later, she was brought into another ER. In addition to the previous symptoms, she had cough, myalgias, and a measles-like petechial rash that began on the palms and soles and spread to the arms, legs, and trunk. She had marked leukocytosis. An immunofluorescent assay showed immunoglobulin G (IgG) antibodies reactive with the suspected pathogen. There was no history of a recent tick bite, but it was reported the family dogs often had ticks which were removed by members of the household. What was the most likely cause?

RMSF.

 

[Apoplexy__]

I'll throw in a couple good ones to know too. Name the microbe:
1. Aplastic anemia in sickle cell?
2. Hyponatremia + pneumonia?
3. Endocarditis after cystoscopy?

1. Parvovirus B19
2. Legionnaire's disease
3. ...Enterococcus?

All correct! Good job man.

To be clear, Enterococcus endocarditis is after genitourinary procedures in general. This is in contrast to Strep bovis endocarditis, which has a GI implication (warrants an investigation for colon cancer).

 

[Macaroon_Berry]

.

 

[MudPhud20XX]

1. Parvovirus B19
2. Legionnaire's disease
3. ...Enterococcus?


I haven't done enough qbank questions to know what the classically tested ones are, but there is the SPANS KEC mnemonic for catalase positive bugs (Staph, pseudomonas, aspergillus, nocardia, serratia, klebsiella, e. coli, candida).


RMSF.

correct.

R. rickettsii is an intracellular bacterium from the spotted fever group Rickettsiae that causes Rocky Mountain Spotted Fever (RMSF). The bacterium infects endothelial cells and is transmitted by the wood tick, Dermacentor andersoni and the dog tick, Dermacentor variabilis. Symptoms of RMSF include fever, headache, myalgia, abdominal pain, vomiting, and diarrhea, followed by a rash that begins on the extremities and spreads to the trunk. The disease can involve multiple organ system failure with diffuse intravascular coagulation (DIC) and shock.

 

[MudPhud20XX]

A 12-year-old boy presents with erythema nodosum, heart murmur, and migratory joint pains involving hands, knees, and ankles. His history is remarkable for an episode of acute pharyngitis 3 weeks ago. Serum C-reactive protein is elevated, and the serologic test reveals high titers of antistreptolysin O (ASO) and anti-deoxyribonuclease (DNAse) antibodies. The pathogenesis of this patient's disease involves antibodies to:

 

[Mr. Mojo Risin]

A 12-year-old boy presents with erythema nodosum, heart murmur, and migratory joint pains involving hands, knees, and ankles. His history is remarkable for an episode of acute pharyngitis 3 weeks ago. Serum C-reactive protein is elevated, and the serologic test reveals high titers of antistreptolysin O (ASO) and anti-deoxyribonuclease (DNAse) antibodies. The pathogenesis of this patient's disease involves antibodies to:

M protein

 

[MudPhud20XX]

correct.

ARF is an immune-mediated disease that develops as a result of the cross-reaction between antibodies directed against streptococcal M protein and cardiac sarcolemma. It typically follows streptococcal pharyngitis but not impetigo. Group A streptococci of any M serotype can be involved.

 

[seminoma]

the same for bugs....

the most common cause of osteomyelitis in sickle cell pts?

Staph aureus is actually more common even in sickle cell patients.

All correct! Good job man.

To be clear, Enterococcus endocarditis is after genitourinary procedures in general. This is in contrast to Strep bovis endocarditis, which has a GI implication (warrants an investigation for colon cancer).

If anyone cares (the NBME might) it might be worth knowing that strep bovis has a new name.. can't remember off the top of my head though.

 

[seminoma]

20 year old male presents with a classic erythematous rash 10 days after returning from a camping trip in Pennsylvania. He is potentially coninfected with what three organisms?

 

[mcloaf]

20 year old male presents with a classic erythematous rash 10 days after returning from a camping trip in Pennsylvania. He is potentially coninfected with what three organisms?

Borrelia, babesia, anaplasma?

 

[seminoma]

Borrelia, babesia, anaplasma?

Yup. Borrelia, babesia, and ehrlichia. I think some people consider ehrlichia/anaplasma the same thing?

 

[mcloaf]

Yup. Borrelia, babesia, and ehrlichia. I think some people consider ehrlichia/anaplasma the same thing?

They are pretty similar/overlapping--I actually have no clue if telling the two apart is within the scope of step 1. They infect different WBCs, have different vectors, and semi-distinct geographic distributions. I went with Anaplasma because its geography is a little more in line with where you see lyme/babesia and it's also classically carried on the Ixodes tick. Then again I think there are also some historical things about naming, and Erlichiosis may be taken to mean infections caused both by anaplasma and ehrlichia (they are in the same family).

I would assume if you were ever expected to tell them apart you'd be told some combination of the tick, the region, and the blood cells involved.

 

[Apoplexy__]

They are pretty similar/overlapping--I actually have no clue if telling the two apart is within the scope of step 1. They infect different WBCs, have different vectors, and semi-distinct geographic distributions. I went with Anaplasma because its geography is a little more in line with where you see lyme/babesia and it's also classically carried on the Ixodes tick. Then again I think there are also some historical things about naming, and Erlichiosis may be taken to mean infections caused both by anaplasma and ehrlichia (they are in the same family).

I would assume if you were ever expected to tell them apart you'd be told some combination of the tick, the region, and the blood cells involved.

I memorized the differences, but never got tested on it in any practice Q or my real deal. Maybe just remember that they're similar rickettsiae and infect WBC's -- if you get a Q on them, you'll probably be able to rule out other answer choices to get it right.

Now the Babesia thing is definitely worth your time. Tested on both Step 1 and 2. They ask about jaundice and/or dark-colored urine after a tick bite.

 

[MudPhud20XX]

A 6-month-old infant was hospitalized with generalized edema and weakness in the upper and lower extremities. His family lived in a remote village in Turkmenistan where immunization was not available. Two weeks earlier, he had a febrile illness with fever, cough, foul breath, and swollen neck. His complete blood count was remarkable for white blood cells (WBCs) of 20,000/μL with 67% polymorphonuclear cells and 10% bands. A chest X-ray (CXR) revealed cardiomegaly and bilateral infiltrates in lower lung fields. Electromyography and nerve conductance test showed evidence of peripheral neuropathy. A Neisser stain of the isolate, recovered from the patient's throat culture, showed club-shaped rods with metachromatic volutin granules. What infectious agent was the most likely cause?

 

[Macaroon_Berry]

c diphtheria ?

 

[mcloaf]

c diphtheria ?

Concur.

 

[Mleechu]

What are the organisms associated with the following scenarios:

1-Culture negative endocarditis
2-Heterophil negative mononucleosis
3- Pleural effusion lymphoma
4-Nasopharyngeal Ca
5-Brain mass in HIV+

 

[Macaroon_Berry]

1. Hacek
2. CMV, Toxoplasma in healthy people
3. ?
4. EBV
5. Toxoplasma

 

[Mleechu]

1. Hacek
2. CMV, Toxoplasma in healthy people
3. ?
4. EBV
5. Toxoplasma

Good job. I'd add few more points

1- Coxiella, bordetella, mycoplasma, chlamydia are also known to cause culture negative endocarditis.

3- Primary Effusion Lymphoma(PEL) is caused by HHV-8 ( kapsosi sarcoma virus) and it is seen in HIV +.

4- toxo is correct. EBV associated CNS lymphoma can also present with brain mass.