Gram Positive Bacteria Flashcards
List the common toxins associated with Staph aureus.
Enterotoxin
Exotoxin
Coagulase
Panton-Valentine leukocidin
You are treating a child for infection and there is the presence of the virulence factor Panton-Valentine. What bacteria are you dealing with?
Staph aureus
Are drugs such as ceftaroline or quinupristin-dalfopristin suitable for MRSA infections in children?
No because they are not FDA approved for use in children.
You are treating and infant for overwhelming sepsis due to gram positive bacteria in clusters in the blood stream. What empiric antibiotic regimen would you give?
Nafcillin +/- vancomycin. Don’t choos vancomycin by itself because nafcillin is more effective for MSSA than vanco.
True or false: Impetigo can be due to Staph or Strep.
True.
You are seeing a child in ICU with a proven Staph aureus brain abscess. What is also a likely condition in this child?
Cyanotic heart lesion. Staph aureus CNS infections are uncommon but brain abscesses are associated with cyanotic heart lesions.
You are treating a patient with TSS and the blood culture is negative. What organisms would then suspect? What if it did grow gram positive cocci?
Staph TSS usually has a negative blood culture. When positive, this is more often associated with Strep pyogenes TSS.
What organisms commonly cause impetigo?
Staph and strep
50% of TSS cases are associated with what population?
Menstruating females
What are the criteria for diagnosing toxic shock syndrome?
Temp > 102
SBP low 3 organ involvement
Negative serology for RMSF, leptospirosis, measles
What is the most common cause of food poisoning in the US?
Staph aureus
What organism is associated with food poisoning due to rice?
Bacillus cereus
You are treating a 13 year old child for infection of his VP shunt. What organism is most likely?
Coag-negative staph such as Staph epi
A 16 year old girl grew Staph saprophyticus in her urine culture. Should this be treated?
Yes, even if she is asymptomatic.
Which of the following antibiotics would be effective in treating a UTI with Staph saprophyticus? (More than one are valid)
Bactrim Nitrofurantoin Cefdinir Cefalexin Ceftriaxone
All except cefdinir, ceftriaxone. Second and third generation cephalopsopins are not effective against Staph saprophyticus
What is the most common organism in otitis media?
Strep pneumoniae
You are treating a patient empirically for otitis media. What antibiotic should you use first? How long of a time with no response should you wait before shifting therapy? What would you switch to?
Amoxicillin (high dose)
48 hours
Amox/clav or 2nd or 3rd gen cephalosporin
An 11-month old child with unilateral otitis media is seen in office. He does not appear unwell. Should he be treated with antibiotics? What is the guideline?
No it is safe to observe so long as they do not have otorrhea. Also safe for bilateral otitis if kid is > 2.
The guideline says 6 mo - 2 years with unilateral disease and otherwise well, ok to observe for 48-72 h.
A 3 year old child with non-purulent bilateral otitis is seen in office. He appears only mildly ill. He is leaving the country in two days. Should he be treated with antibiotics? What is the guideline?
Yes. It’s bilateral and this can be observed at his age but he cannot get close follow-up in 48-72 hours. Since you can’t reassess, you have to treat.
True or false: a child in the icu has a systemic strep infection and is seriously ill. The serotype is 19A. This proves he was not immunized with Prevnar.
False. Prevnar doesn’t cover this. It has become the most common strain in immunized children with invasive strep infection. It is also associated with increased abx resistance.
What particularly relevant strep strain is covered by PCV13 vs. PCV7?
Strep serotype 19A. Even older kids should get this if they are at risk.
True or false: strep pneumo is the most common cause of all pneumonia in kids.
False. Viral infections are most common. Strep is, however, the most common bacterial cause.
Other than E. coli O157:H7, what is the second most common cause of HUS?
Invasive strep pneumo.
A 2 month old infant has recovered from strep pneumo meningitis. What must be closely monitored at his well child checks?
Hearing. Up to 30% will suffer hearing loss.
What cell surface protein is a determinant of strep pyogenes virulence?
M protein
To avoid the complications associated with strep pyogenes infection, antibiotics must be started within how many days?
- That’s why you have time to wait on strep culture.
A 9 year old boy is in your clinic with a reddish sandpaper-like rash on his trunk and shoulders. He has lighter skin color around his lips. What infection should you be concerned about?
Strep pyogenes (scarlet fever)
A 9 year old boy is in your clinic with a reddish sandpaper-like rash on his trunk and shoulders. He has lighter skin color around his lips. What other findings would you look for that would support you suspicion of scarlet fever?
Pastia lines
Antecubital fossa rash
Flexor creases rash
Later in the coarse, desquamation.
How are impetigo and erysipelas the same? How are they different?
Both are most commonly strep infections. Erysipelas is infection of the deeper tissues. It is tender whereas impetigo is not tender.
You are seeing a 4 you old with honey-crusted lesions around his mouth. What symptom would change your opinion that this is impetigo?
If they were painful. Impetigo is not usually painful.
Infection with or recent infection with what virus is a risk factor for group A strep cellulitis?
Varicella
In a PCN allergic (anaphylaxis) child who has strep throat, is azithromycin an acceptable alternative?
Yes but there is resistance in 5-10% cases.
True or false: a child who was just diagnosed with strep throat has developed hematuria. This means he has strep glomerulonephritis.
False. This is probably IgA nephropathy. Strep glomerulonephritis has a latency of 21 days.
Pregnant women are tested for GBS prior to delivery. What is the full name of that bacteria?
Streptococcus agalactiae
Infants are given ampicillin when they are being treated for sepsis. What particular bacteria are covered by the ampicillin
Streptococcus agalactiae and listeria
What are the timeframe for early onset, late onset, and late – late onset GBS?
0 to 7 days
Seven days to three months
After three months
An infant is being treated for GBS infection of the proximal humerus. Was this likely to have been early, late, or late late onset?
Late onset.
Which GBS serotype is responsible for 90% of late onset GBS infection?
Serotype iii
You are seeing a infant suspected of group B strep infection. Which of the following is the best test to confirm the diagnosis?
A: blood culture
B. Urine GBB antigen test
C. Serum GPS antigen test
D. Heterophile antibody test
A. Blood culture is the gold standard. Antigen testing would only be useful in the situation where an infant has been on antibiotics already for other causes.
Which two antibiotics should most newborn infant be placed on if there is concern for sepsis?
Ampicillin plus gentamicin
What is the treatment duration for group B strep pneumonia? Bacteremia? Meningitis? Osteomyelitis?
10 days
10 days
14 to 21 days
3 to 4 weeks
Does maternal prophylaxis for group B strep have any affect on late onset disease?
No, it only prevents early onset disease
You are treating a 13 year old child for M RSA pneumonia. He has a true allergy to vancomycin. Can you use daptomycin?
No. Daptomycin is not approved for use in children. And infectious disease physician might resort to this in true vancomycin allergy, but daptomycin does not cover MRSA pneumonia.
Which organism is the most common cause of endocarditis in children with up to1/3 of cases due to it?
Strep viridans
You’re seeing a teenager and follow up for a pharyngitis. His throat culture grew group C streptococcus. True or false. He must be treated with antibiotics to prevent rheumatic fever.
False. Only group a strep (strep pyogenes) is associated with rheumatic fever.
You are treating an infant in the nicu for enterococcus line sepsis. What empiric antibiotic regimen should you choose?
Ampicillin for vancomycin plus gentamicin. You must use the combination because ampicillin and vancomycin alone are only inhibitory.
Which antibiotic should you use if you’re treating a child with vancomycin resistant enterococcus?
Linezolid
A septic neonate is growing diphtheroid like organisms from the CSF. When he was born, the amniotic fluid was brown stained. What organism should you consider? What is the best empiric treatment?
Listeria
Ampicillin
What infection is associated with granulomatosis Infantisepticum?
Listeriosis
What type of cheese is particularly associated with listeriosis?
Goat cheese
What organism is responsible for pharyngitis in college outbreaks? (Think bacterial.)
Group C streptococcus. Remember, this is not associated with rheumatic fever. Only group a strep carries that risk.
Strep bovis endocarditis and adults is associated with what type of cancer?
Colon cancer
What is the best antibiotic for treatment of bacteremia due to enterococcus faecium?
Ampicillin or vancomycin + gentamicin.
Remember, ampicillin and vancomycin are only inhibitory for enterococcus.
Which age group has the highest incidence of listeria infection?
Infants less than one month of age
True or false: a blood culture grows an organism preliminarily identified as diphtheroids with final identification available the next day. In a neonate, it is probably safe to assume that this organism is a contaminant.
False. This is likely listeria.
You’re seeing a 10-year-old in office with a low-grade fever, horse voice, and a swollen neck (bull neck). How should you treat this patient?
This patient has diphtheria.
Equine antitoxin and Erythromycin. The purpose of the erythromycin is to render the patient non-contagious. Second line choice is penicillin. Also, after recovery, immunize the patient with diphtheria toxoid.
You’re seeing a 13-year-old with horse voice and you suspect diphtheria. Which would support your suspicion: a temperature of 103 or a temperature of 100?
- The temp is usually low-grade.
What cardiac complication can develop in patients with diphtheria?
Myocarditis and arrhythmias.
What neurologic complications can occur with diphtheria?
A Guillan-Barre type syndrome or isolated peripheral nerve palsies.
You are seeing an adolescent with strep-like illness but his throat culture actually grew arcanobacterium haemolyticum. What is the treatment of choice?
Erythromycin. Pcn may fail.
A 10 year old presents with painless papules, some with black eschar. All have induration. He raises sheep for 4H. What is the treatment of choice?
Cipro or doxy.
You can use pcn if susceptible.
What are the three possible clinical presentations of anthrax?
Cutaneous (most common)
Pulmonic
Gastrointestinal.
What is the treatment of choice for anthrax exposure prophylaxis? What is the duration?
Ciprofloxacin or doxycycline for 30 to 60 days
Food-born bacillus cereus enteritis is associated with what food item?
Fried rice left out on the counter.
There are two forms of bacillus cereus enteritis. Describe the two forms and their related toxins.
- Short incubation (1-6 hr) due to heat stable toxin.
2. Longer incubation (8-16 hr) due to heat labile enterotoxin produced in vivo.
For mild to moderate disease, what is the treatment regimen for C diff infection first occurrence? Second occurrence? Third occurrence?
Metronidazole
Metronidazole
Vancomycin
Don’t use metronidazole past the first recurrence because of neurotoxicity.
For gas gangrene, what organisms are typical? What is the typical treatment?
C perfringiens is most common but can be speticum, tetani, sordellii, or novyi.
Treat with PCN and surgical debridement.
A refugee from a developing country brings in her infant who is 10 days old. The infant is fussy, crying, and seems unable to latch where in the preceding few days he was latching fine. Her culture has a practice of spreading manure on the umbilical cord. What illness should you think of?
Tetanus.
What is the treatment for active tetanus infection?
Human tetanus immunoglobulin (TIG)
Metronidazole
You can use PCN G is also acceptable.
TETANUS PROPHYLAXIS
NO treatment is required in two scenarios. What are they?
- CLEAN WOUND and immunizations up to date (most recent
TETANUS PROPHYLAXIS
There is one scenario where a child would get TIG and immunized as prophylaxis. What are the criteria?
Dirty wound and
A 17 year old girl is seen in office for a dirty wound and you have determined she needs tetanus immunization prophylaxis. Which tetanus immunization should she get?
Tdap if she has not had Tdap before. Otherwise, Td.
TETANUS SCENARIOS
Marla ha a staple injury (a clean, minor wound). She has had either an unknown number of tetanus immunizations or a known number
If
TETANUS SCENARIOS
Marla has a staple injury. She has had >= 3 prior tetanus immunizations with the last one
Nothing
TETANUS SCENARIOS
Marla has a staply injury anbd has had >= 3 prior tetanus immunizations. Her last was > 10 years ago. What should she get?
Tdap
TETANUS SCENARIOS
Marla steps on a dirty nail with cow feces on it. Her dog licks the foot after the injury. She has an unknown number of immunizations or a known number
TIG! Also give her immunization. If age
TETANUS SCENARIOS
Marla steps on a dirty nail with cow feces on it and her dog licks the foot after the injury. She has had >=3 immunizations with the most recent
Nothing
TETANUS SCENARIOS
Marla steps on a dirty nail with cow feces on it and her dog licks it after. She has had >= 3 immunizations with the most recent 5.5 years ago. What should she get?
DTap if
