NAPLEX / Infectious disease

Answer A,B,C and E. Advanced age, previous antimicrobial usage, duration of hospitalization, cancer chemotherapy, GI surgery, tube feeding, and use of acid-suppressing medications.
Reference:
Cohen S, Gerding D, Johnson S et al. Clinical Practice Guidelines for Clostridium difficile Infection in Adults: 2010 Update by the Society for Healthcare Epidemiology of America (SHEA) and the Infectious Diseases Society of America (IDSA). Infection Control and Hospital Epidemiology. 2010;31(5):431-455. Doi: 10.1086/651706

Answer D. Primary treatment for stenotrophomonas maltophilia is SMX-TMP. Meropenem, ciprofloxacin, and vancomycin have no coverage. Levofloxacin may work as well but is not the 1st line agent.

Answer E. The IDSA guidelines state that Pasteurella species are commonly cultured from animal bites, purulent and non-purulent.
Reference:
Reference: Stevens, Dennis L., et al. "Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America." Clinical Infectious Diseases (2014): ciu296. Available at: https://academic.oup.com/cid/article/59/2/e10/2895845/Practice-Guidelines-for-the-Diagnosis-and Management of Skin and Soft Tissue Infection.

Answer A. The IDSA guidelines recommends Augmentin for the initial treatment of an infection caused by an animal bite. Augmentin covers most of the aerobic and anaerobic bacteria that cause the infection. The other antibiotics listed here are not recommended, though ampicillin-sulbactam is recommended in the case of an infection caused by a human bite.
Reference:
Reference: Stevens, Dennis L., et al. "Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America." Clinical Infectious Diseases (2014): ciu296. Available at: https://academic.oup.com/cid/article/59/2/e10/2895845/Practice-Guidelines-for-the-Diagnosis-and Management of Skin and Soft Tissue Infection.

Answer A. The IDSA guidelines recommends Augmentin for the initial treatment of an infection caused by an animal bite. Augmentin covers most of the aerobic and anaerobic bacteria that cause the infection. The other antibiotics listed here are not recommended, though ampicillin-sulbactam is recommended in the case of an infection caused by a human bite.
Reference:
Reference: Stevens, Dennis L., et al. "Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America." Clinical Infectious Diseases (2014): ciu296. Available at: https://academic.oup.com/cid/article/59/2/e10/2895845/Practice-Guidelines-for-the-Diagnosis-and Management of Skin and Soft Tissue Infection.

Answer A. The IDSA SSTI guidelines recommends antimicrobial agents active against gram-negative bacteria and anaerobes, such as cephalosporins or fluoroquinolones, to be used in combination with metronidazole when treating a surgical site infection following an operation on the axilla, GI tract, perineum, or, as with this patient, female genital tract. The patient is allergic to fluoroquinolones, so ciprofloxacin should not be used for this patient. Reference: Stevens, Dennis L., et al. "Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America." Clinical Infectious Diseases (2014): ciu296. Available at: https://academic.oup.com/cid/article/59/2/e10/2895845/Practice-Guidelines-for-the-Diagnosis-and

Answer A. This patient is displaying signs of a severe case of cellulitis. Severe cellulitis is defined as having one of the following: failed oral antibiotic treatment, immunocompromised, clinical signs of deeper infection, or meeting the SIRS criteria. Based on this patient’s presentation they have failed antibiotic treatment and meet SIRS criteria. For severe cellulitis, IDSA SSTI guidelines recommend using Vancomycin along with Zosyn.
Reference:
Reference: Stevens, Dennis L., et al. "Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America." Clinical Infectious Diseases (2014): ciu296. Available at: https://academic.oup.com/cid/article/59/2/e10/2895845/Practice-Guidelines-for-the-Diagnosis-and Management of Skin and Soft Tissue Infection.

Answer A. This patient is showing signs of erysipelas. The patient does not appear to have a systemic infection, this indicates the infection is mild and can be treated effectively with oral medication in the outpatient setting. Linezolid and vancomycin are not recommended because MRSA is not suspected in this patient. Cephalexin has the most specific (narrow) coverage for streptococcus out of these antibiotics.
Reference:
Reference: Stevens, Dennis L., et al. "Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America." Clinical Infectious Diseases (2014): ciu296. Available at: https://academic.oup.com/cid/article/59/2/e10/2895845/Practice-Guidelines-for-the-Diagnosis-and Management of Skin and Soft Tissue Infection.

Answer B. Purulent skin soft tissue infection are most likely caused by Staph. Aureus. Empiric antibiotic should be targeted to Staph. Aureus. Streptococcus is normally found from the Nonpurulent necrotizing Infections. E. Coli is normally found in the UTI and intra-abdominal infection. Pseudomonas aeruginosa is found in Diabetic wound and infections associated with burns.
Reference:
Reference: Stevens, Dennis L., et al. "Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America." Clinical Infectious Diseases (2014): ciu296. Available at: https://academic.oup.com/cid/article/59/2/e10/2895845/Practice-Guidelines-for-the-Diagnosis-and Management of Skin and Soft Tissue Infection.

Answer B. The IDSA SSTI treatment guidelines recommends treating empirically with doxycycline or SMX/TMP in patients presenting with moderate purulent SSTI. Since this patient has a sulfa allergy SMX/TMP cannot be used in this patient. Doxycycline is the drug of choice here. Linezolid would be appropriate if the patient was presenting with a severe purulent SSTI indicated by meeting SIRS criteria or previously failing antibiotic therapy.
Reference:
Reference: Stevens, Dennis L., et al. "Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America." Clinical Infectious Diseases (2014): ciu296. Available at: https://academic.oup.com/cid/article/59/2/e10/2895845/Practice-Guidelines-for-the-Diagnosis-and Management of Skin and Soft Tissue Infection.