ABSITE Review - Infection Flashcards
What is the MC immune deficiency?
Malnutrition
What is the microflora in the stomach?
Virtually sterile; some GPCs, some yeast
What is the microflora in the proximal small bowel?
10^5 bacteria, mostly GPCs
What is the microflora in the distal small bowel?
10^7 bacteria, GPCs, GPRs, GNRs
What is the microflora in the colon?
10^11 bacteria, almost all anaerobes, some GNRs, GPCs
What is the MC organisms in the GI tract?
Anaerobes
What is the MC anaerobe in the colon?
Bacteroides fragilis
What is the MC aerobic bacteria in the colon?
Escherichia coli
What is the MC organism in gram-negative sepsis?
Escherichia coli
What is the endotoxin of gram-negative organisms? What it triggers?
Lipopolysaccharide lipid A
Triggers the release of TNF-alpha (from macrophages), activates complement and coagulation cascade
How clostridium difficile can be diagnosed? What is the treatment?
Dx - Fecal leukocytes in stool, C.difficile toxin
Tx - oral or IV flagyl, oral vancomycin, lactobacillus
How you classify the wound of an elective colon resection with prepped bowel?
Clean-contaminated = 3-5% risk of wound infection
How you classify the wound of GSW to colon with repair?
Contaminated = 5-10% risk of wound infection
How many bacteria are needed for a wound infection?
10^5 bacteria
Mention some risk factors for wound infection.
Long operations, hematoma or seroma formation, advanced age, chronic disease (COPD, renal failure, liver failure, DM), malnutrition, immunosuppressive drugs
Which are the agents involve with invasive soft tissue infection?
Clostridium perfringens and beta-hemolytic strep
What are the MC agents in ICU pneumonia?
#1 - Staph aureus #2 - Pseudomonas
What are the MC agents in ICU pneumonia?
#1 - Staph epidermidis #2 - Staph aureus #3 - yeast
What are the MC agents in necrotizing soft tissue infection?
Beta-hemolytic, Streptococcus (group A), C.perfringens and mixed organism
Mention signs and symptoms of necrotizing soft tissue infection.
WBC 20, thin gray drainage, marked induration, edema of entire limb, hypoNa (<135), skin blistering/slougihng, skin necrosis, crepitus/soft tissue gas on x-ray, pain out of proportion, sepsis
What is the treatment for necrotizing fasciitis?
Early debridement, high-dose penicillin or broad spectrum abx if polyorganismal
What is the toxin of C.perfringens?
Alpha-toxin
What is the MC presentation of C. perfringens? Describe the gram stain.
Myonecrosis and gas gangrene
Gram stain - GPRs without WBCs
C. perfringens is common in __________ injuries.
Farming
What is Fournier’s gangrene? Mention some risk factors.
Severe infection in perineal and scrotal region
RFs - DM, immunocopromised state
What are common symptoms of Actinomyces? What is the treatment?
MC - Pulmonary symptoms, tortous abscesses in cervical, thoracic, ad abdominal areas
Tx - drainage and penicillin G
What are common symptoms of Nocardia? What is the treatment?
Pulmonary and CNS symptoms
Tx - drainage and sulfonamides (Bactrim)
What are common symptoms of Histoplasmosis? What is the treatment?
Pulmonary symptoms, Mississippi and Ohio River valleys
Tx - amphotericin for severe infections
What are common symptoms of Cryptococcus? What is the treatment?
CNS symptoms
Tx - amphotericin for severe infections
What are common symptoms of Coccidiodomycosis? What is the treatment?
Pulmonary symptoms, Southwest
Tx - amphotericin for severe infections
What is a risk factor for SBP?
Protein < 1g/dLin peritoneal fluid
How is SBP diagnosed?
PMNs > 500 in peritoneal fluid is diagnostic
What is the treatment of SBP? Short-term prophylaxis?
Ceftriaxone, prophylaxis with fluoroquinolones
What are the 2 MCCs of laparotomy in HIV patients?
#1 - CMV infection #2 - neoplastic disease
Is upper or lower GI bleeding more common in HIV patients?
Lower GI bleeding is more common
Upper GI bleeds - Kaposi, lymphoma
Lower GI bleeds - CMV, bacterial, HSV
What is the bacteria in cat and dog bites?
Pausterella multocida
What is the bacteria in human bites?
Eikenella
