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MI11.1-3 | Antimicrobial Resistance & Stewardship — Case Study
CLINICAL SCENARIO
You are a third-year MBBS student attached to the Department of Microbiology at a 500-bed tertiary-care teaching hospital in Pune. The Infection Control Committee has flagged Ward 6 (general medicine) for unusually high rates of antibiotic-resistant infections over the past quarter. The ward has 32 beds with an average occupancy of 90%. The antibiotic stewardship pharmacist, Dr. Meera Joshi, has asked you to (a) interpret the ward antibiogram and (b) draft a targeted stewardship intervention proposal for ward rounds.
The Ward 6 Antibiogram (last quarter, n=48 isolates):
| Organism (n) | Amoxicillin-clav | Ceftriaxone | Piperacillin-Taz | Meropenem | Colistin |
|---|---|---|---|---|---|
| E. coli (22) | 38% S | 45% S | 72% S | 91% S | 100% S |
| Klebsiella pneumoniae (14) | 21% S | 29% S | 55% S | 71% S | 100% S |
| Pseudomonas aeruginosa (8) | - | - | 62% S | 78% S | 100% S |
| Acinetobacter baumannii (4) | - | - | 12% S | 35% S | 100% S |
Additional data: 68% of E. coli isolates are ESBL-producing. 43% of Klebsiella isolates are carbapenemase-producing (OXA-48 and NDM detected). 75% of Acinetobacter isolates are pan-resistant to all agents except colistin.
Instructions
Read the scenario and antibiogram carefully. Answer ALL four sections. Use the ward antibiogram data to ground your responses. Total word guidance: 600–800 words across all sections.
Section 1 (Antibiogram Interpretation): Interpret the antibiogram for the dominant organism (E. coli) and explain the clinical significance of the ESBL prevalence figure.
Section 2 (Resistance Pattern Analysis): Identify the two most clinically alarming findings in the antibiogram. Justify your choice using resistance mechanisms covered in this module.
Section 3 (Stewardship Intervention Design): Design a three-point antimicrobial stewardship intervention for Ward 6. Each point must name the specific strategy (from the AMSP framework), describe the implementation step, and explain how it addresses the antibiogram finding.
Section 4 (Your Role as a Future Clinician): Describe two specific actions you will take as a junior doctor in this ward to contribute to the stewardship programme — beyond just following guidelines.
Length: 600-800 words
What to Submit
Section 1: Antibiogram Interpretation for E. coli
Interpret the E. coli antibiogram data. What does 68% ESBL prevalence mean for empirical antibiotic choices in this ward?
Guidance: Explain what ESBL means, how it affects which antibiotics can be used, and the clinical implication of using a cephalosporin in an ESBL producer despite an apparently susceptible result. Reference the reporting rule (CLSI/EUCAST). Approx. 150 words.
Section 2: Most Alarming Resistance Patterns
Identify and justify the two most clinically alarming findings in the Ward 6 antibiogram.
Guidance: Look beyond individual susceptibility percentages to the combination of findings. Consider: Which resistance mechanisms are present? Which organisms have the fewest remaining treatment options? What does 43% carbapenemase-producing Klebsiella mean for the ward? Approx. 150 words.
Section 3: Three-Point Stewardship Intervention
Design three specific AMSP interventions for Ward 6. Each must name the strategy, describe implementation, and link to the antibiogram finding.
Guidance: Choose from: formulary restriction/preauthorisation, prospective audit with feedback, antibiogram-guided empirical therapy guidelines, culture-before-antibiotic policy, de-escalation protocol. Be specific — 'don't use carbapenems' is not an intervention; a documented 72-hour review trigger with ID pharmacist sign-off is. Approx. 200 words.
Section 4: Your Role as a Junior Clinician
Beyond following guidelines, what two personal actions will you commit to as a junior doctor in this ward to contribute to antimicrobial stewardship?
Guidance: Think about communication, documentation, culture practices, consultation behaviours, and peer influence. Avoid vague statements ('prescribe wisely'). Name the concrete action and explain why it matters. Approx. 100 words.
Grading Rubric — Antibiogram Interpretation & Stewardship Intervention Rubric (25 points)
| Criterion | Points | Full-marks descriptor |
|---|---|---|
| Section 1 — Antibiogram Interpretation: Accuracy and clinical reasoning about E. coli ESBL data and its prescribing implications | 6 pts | Accurately explains ESBL mechanism, correctly applies CLSI reporting rule (report all cephalosporins as resistant), clearly explains why empirical cephalosporins are clinically dangerous despite in-vitro susceptibility, and correctly identifies carbapenems or temocillin as appropriate alternatives for serious infections. |
| Section 2 — Resistance Pattern Analysis: Identification and mechanistic justification of the two most alarming findings | 6 pts | Identifies both 43% CPE Klebsiella (OXA-48/NDM) and 75% pan-resistant Acinetobacter as the two most alarming findings. Correctly explains the mechanism of each (carbapenemase-mediated hydrolysis for Klebsiella; multi-mechanism including MBL, porin loss, efflux, AmpC for Acinetobacter). Explicitly connects to severely limited therapeutic options (colistin-sparing agents only). |
| Section 3 — Stewardship Intervention Design: Quality, specificity, and mechanistic grounding of the three proposed interventions | 9 pts | Three distinct AMSP strategies named correctly (e.g. preauthorisation restriction, prospective 72-hour audit, culture-before-antibiotic). Each implementation step is concrete and operationally feasible (e.g. 'meropenem requires ID pharmacist approval for empirical use after culture sent'). Each explicitly links to the specific antibiogram finding it addresses. |
| Section 4 — Personal Stewardship Role: Specificity, realism, and self-reflective commitment | 4 pts | Two concrete, named personal actions that go beyond passive guideline compliance — e.g. 'Always send a blood culture before initiating antibiotics for suspected sepsis and document the collection in the case notes before prescribing' and 'Raise the antibiogram findings in morning rounds when a broad-spectrum antibiotic is prescribed without documented review'. Both explain why the action matters. |
PEER REVIEW
Your peer's response will be shared with you for structured feedback. Review Sections 1 and 3 only. For Section 1: Does the response correctly apply the ESBL reporting rule? Does it explain why empirical cephalosporins fail even when the zone looks 'susceptible'? For Section 3: Are the three interventions distinct AMSP strategies (not the same idea restated)? Is each intervention operationally specific — could a ward manager actually implement it? Provide 2–3 sentences of specific, constructive feedback for each section. Avoid vague praise. Point to at least one strength and one area for improvement.