| Course | PA 514 Comprehensive Clinical Module Infectious Disease |
|---|---|
| Week | 5 |
| Paper type | Culture narrowing memo |
| Length | About 680 words, 5 pages |
| Format | APA 7 student paper |
| School | Chamberlain University |
| Program | Master of Physician Assistant Studies (MPAS) |
| Updated | October 2026 |
Free sample paper for PA 514 Week 5
Culture Narrowing Memo: Salmonella From Two Blood Culture Sets, Ampicillin Removed, Ceftriaxone Kept and Ciprofloxacin Passed Over at an MIC of 0.25
Student Name
Chamberlain University
PA 514: Comprehensive Clinical Module Infectious Disease
Instructor Name
Month Day, Year
Culture Narrowing Memo: Salmonella From Two Blood Culture Sets, Ampicillin Removed, Ceftriaxone Kept and Ciprofloxacin Passed Over at an MIC of 0.25
The Report, as Received
Blood cultures: two sets collected Thursday, April 9, at 10:50 p.m., before the first antibiotic dose. Both flagged positive Friday, April 10, at 1:15 p.m.; Gram stain gram-negative rods. Identification released Saturday, April 11, at 9:05 a.m.: Salmonella species, serogroup B. Susceptibilities released Sunday, April 12, at 4:30 p.m.
Table 1
Blood Isolate Susceptibilities as Reported
| Agent | MIC | Interpretation |
|---|---|---|
| Ampicillin | 32 or more | Resistant |
| Ceftriaxone | 1 or less | Susceptible |
| Ciprofloxacin | 0.25 | Intermediate |
| Trimethoprim-sulfamethoxazole | 20 or less | Susceptible |
Note. Note. MIC in micrograms per milliliter; interpretations as printed by the laboratory using current breakpoints.
Stool multiplex panel: collected Friday, April 10, 6:10 a.m., resulted 6:20 p.m.: Salmonella detected; Campylobacter, Shiga toxin genes and other targets not detected. Repeat blood cultures collected Saturday, April 11, 7:00 a.m.: no growth at 24 hours.
The gap between collection and release, almost three days for the susceptibilities, is why the empiric plan had to stand on its own until now.
Finding or Passenger
Blood is a sterile site. Salmonella growing in two separate sets is a true bloodstream infection, not contamination. The stool panel detects DNA from a nonsterile site and could, in another patient, reflect carriage; here it agrees with the blood and with the chick exposure, so it is read as the same infection.
Removals, Retentions, Additions
Removed: ampicillin. The blood grew a gram-negative organism, not Listeria, and the isolate is resistant to ampicillin, so the drug is neither aimed at a remaining candidate nor active against the organism found.
Retained: ceftriaxone 2 g every 24 hours. The isolate is susceptible, and ceftriaxone is a listed option for nontyphoidal Salmonella in an immunosuppressed host (Shane et al., 2017).
Not added: ciprofloxacin. The MIC of 0.25 is in the intermediate range for Salmonella under current laboratory breakpoints (Clinical and Laboratory Standards Institute, 2024), and fluoroquinolones are less reliable at that level. Trimethoprim-sulfamethoxazole is susceptible but is avoided because of R.A.'s methotrexate.
The Coverage Given Up
Stopping ampicillin gives up Listeria coverage. That is accepted because the blood grew another organism, and a second bloodstream organism is unlikely. It would be reconsidered if a later culture grew gram-positive rods or if R.A. developed headache, confusion or neck stiffness. Campylobacter and Shiga toxin are no longer candidates, since the stool panel did not detect them.
How the Plan Was Communicated
The change was discussed with the attending hospitalist before the order was written and entered on Sunday evening, so the 10 p.m. ampicillin dose was the last. The bedside nurse was told why the four-hourly infusions were ending, and the pharmacist was asked to review the remaining regimen against R.A.'s kidney function, which had improved to a creatinine of 1.0 with fluids. R.A. was told that the infection had been identified, that one of the two antibiotics was no longer needed and that the other would continue. The infectious diseases service, consulted on Friday when the cultures flagged, agreed with the narrowing by phone.
Gaps in the Report
It does not give the serotype, which the state laboratory will determine from the isolate. It does not say whether the infection has seeded a blood vessel or a joint, which matters in a patient over 50 and will be considered in the treatment length. And an intermediate result for ciprofloxacin does not say the drug would fail, only that it is less reliable. The memo therefore asks for three follow-ups: the serotype from the state laboratory when it is posted, a decision on imaging if back pain, a new murmur or a swollen joint appears, and a fixed day to settle the total course length once the repeat cultures are final at five days.
References
Clinical and Laboratory Standards Institute. (2024). Performance standards for antimicrobial susceptibility testing (34th ed., CLSI supplement M100).
Shane, A. L., Mody, R. K., Crump, J. A., Tarr, P. I., Steiner, T. S., Kotloff, K., Langley, J. M., Wanke, C., Warren, C. A., Cheng, A. C., Cantey, J., & Pickering, L. K. (2017). 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea. Clinical Infectious Diseases, 65(12), e45-e80. https://doi.org/10.1093/cid/cix669
What the PA 514 Week 5 assignment asks for
In week five the empiric plan meets the culture report, and the memo explains how therapy changes. Reproduce the report as received, including collection times, release times, identification and each susceptibility with its MIC and interpretation, so a reader can see when information arrived. Decide whether each positive result is a true finding or a contaminant or colonizer, using the specimen site and the number of positive sets. Then sort every drug into removed, retained or added, and tie each decision to a specific line of the report and a cited source. Say what coverage is lost by narrowing and what would bring it back. Record how the change was communicated and who agreed. Close with what the report does not tell you. Use memo format with To, From, Date and Subject lines.
How this PA 514 Week 5 example is built
The memo is addressed from the PA student to the attending hospitalist and dated Sunday, April 12. Its first section copies the report: two blood sets drawn before the first dose, flagged Friday, identified Saturday and with susceptibilities released Sunday, shown in Table 1 with MICs for ampicillin, ceftriaxone, ciprofloxacin and trimethoprim-sulfamethoxazole. The stool panel and the negative repeat cultures are added. A finding or passenger section treats the blood isolate as real and reads the stool result as the same infection. Ampicillin is removed, ceftriaxone kept with an IDSA citation and ciprofloxacin passed over using CLSI M100 breakpoints. The lost Listeria coverage is accepted with triggers for its return. Communication with the nurse, pharmacist, patient and infectious diseases service is recorded, and the gaps section ends with three dated follow-ups.
Reading the PA 514 Week 5 grading rubric
Grading here centers on whether every change in therapy points back to a specific result. A memo that simply announces the new regimen loses the largest share, because the reader cannot check it. Next comes interpretation of the report itself: treating a stool result or a single set as equal to two sterile-site cultures, or misreading an intermediate MIC, costs heavily. Faculty give real credit for naming the coverage surrendered by narrowing and the signs that would reverse it, since that is where narrowing becomes safe. Communication carries a smaller share, rewarded when the memo states who agreed and when the order took effect. Deductions also follow for missing release times, a table without units and memo headings that are absent or incomplete. References to breakpoint standards must be current editions.
Common PA 514 Week 5 mistakes, and how to avoid them
The usual setback with this memo is rewriting the plan without showing which line of the report caused each change. Send your culture and susceptibility report and the empiric regimen from your case, and the requested memo will copy the report into a dated table, judge each positive result and then sort every drug into removed, retained or added with its reason. Intermediate and resistant results are explained in terms of what they mean for the drug choice, not just restated. The section on surrendered coverage names the clinical signs that would bring a drug back. If your instructor wants a different memo layout or a stewardship form, the sample follows it. Your own case values, dose checks and final regimen should still be confirmed before submission.
Get a PA-514 Week 5 example written to your instructions
Send the Week 5 instructions with the case and whatever laboratory report your section attached to it, and a custom example is returned inside 24 to 48 hours with every change tied back to a line of that report. The first one is free. A supplied memo template is filled in as issued rather than replaced with something tidier.
More PA 514 papers and MPAS samples
- PA 514 Week 1: Exposure-First Discussion Post
- PA 514 Week 2: Exposure History Timeline
- PA 514 Week 3: Incubation Window Analysis
- PA 514 Week 4: Empiric Coverage Rationale
- PA 514 Week 6: Antibiogram Reading Exercise
- PA 514 Week 7: Stop Date Justification
- PA 514 Week 8: Reportable Condition Brief
- PA 512 Week 5: Serial Value Table
- PA 510 Week 5: Skin Tone Description Audit
- PA 505 Week 5: Delirium Versus Depression
- PA 504 Week 5: Interpreted Encounter Analysis
PA 514 Week 5 questions, answered
The report names an organism nobody on our list predicted.
That is a common setup here and it is not a failure of the earlier work. The memo records the surprise, says which part of the history the result now points back at, and changes the plan on the report rather than on the original reasoning. Most sections award points for revisiting the exposure account rather than for defending the first list.
Do intermediate results count?
They are usually the part a rubric looks for, because a susceptible column is easy to read and everything else needs a sentence. The memo states what the laboratory reported for each element rather than sorting results into two piles, and where the report carries a comment or a footnote, that gets quoted rather than summarized away.
Our case has two organisms.
Then the memo handles them separately and says so in its opening line, since a change justified by one report and applied to both is the error the setup is testing for. Each organism keeps its own site, its own dates and its own set of changes, and the closing paragraph states where the two plans overlap.
Where can I find a free PA 514 Week 5 sample paper?
A complete PA 514 Week 5 culture narrowing memo is on this page, with the susceptibility table, each drug decision tied to a result and the follow-ups still open.
Why is ciprofloxacin not used in the PA 514 Week 5 memo?
The isolate's MIC of 0.25 reads as intermediate under current CLSI breakpoints, so a fluoroquinolone is less reliable than the susceptible ceftriaxone already running.