Tufts at Tech Research Advances Antimicrobial Stewardship and Access to Veterinary Care

The impetus for the study was to determine if in-house screening tools perform as well at detecting bacteria in urine (bacteriuria) as sending samples to a reference lab for antimicrobial susceptibility testing (C&S), the historical standard. The presence of bacteriuria indicates a UTI, which shares many of the same symptoms as other lower urinary tract diseases, such as stones or bladder cancer. C&S is more expensive than in-house testing options, running at a cost to the owner of a few hundred dollars, depending on the individual clinic. Tufts at Tech has always run urine cultures in-house, offered at a much lower cost because the samples are not submitted to a reference laboratory.  

“Even though we’ve been doing this here for over 10 years, it’s not found in any veterinary literature, so the goal was to publish literature that vets can do this, and it’s significantly less expensive than sending cultures out,” says Sample.

Sample felt some initial apprehension about taking on the study since she had no formal research training prior to her residency, but she had a strong team behind her. Cummings School professors who contributed to and co-authored the study include Dr. Claire Fellman, Dr. Jennifer Grady V12, and Tufts at Tech Director Dr. Greg Wolfus V98, in addition to Benjamin Koethe, a statistician at Tufts Clinical and Translational Science Institute. Sarah Tainter, a veterinary assistant at Tufts at Tech, also played an integral part in the study by performing the in-house testing and recording data.

The team compared three in-house screening tools for identifying bacteria with C&S: the in-house culture plate and two table-side tests, a computerized urine sediment analyzer, and a rapid immunoassay. Over one year, the team tested urine samples of 101 canine patients at Tufts at Tech with UTI symptoms, such as incontinence or blood in the urine, using all four methods.

The results backed up Sample’s hypothesis that the three in-house tests would accurately detect the presence of bacteriuria. The in-house culture plates were the least expensive option with the highest accuracy. The paper suggests that veterinarians should consider using these in-house tests to rule out a UTI as the cause of a patient’s symptoms to more accurately determine which pets would benefit from antibiotics and how to best prioritize client resources if further workup is needed. All three tests performed well to rule out bacteria, with the in-house urine cultures having a 99% negative predictive value, meaning that 99% of the pets tested negative on an in-house plate did not have bacteria in their urine.

The paper also elucidates an additional benefit, beyond expense, of utilizing these in-house tools before pulling in the laboratory: antimicrobial stewardship. Only 25 of the 101 cultures tested were positive for bacteriuria.

Grady (she/her), co-author of the study and Sample’s residency advisor explains, “One of the big takeaways is that 75% of the urine cultures we submit for canine patients will be negative for bacterial growth. Our research demonstrated that a negative urine culture result could be accurately predicted by all three of the inexpensive in-house methodologies, particularly the in-house urine culture plating. This would allow 75% of the pet owners to avoid the high cost of send-out urine culture, but still rule out bacterial infection as a cause of their pet’s clinical problems.”

While UTIs are treated with antibiotics, other urinary tract diseases are not. Sample explains that many practitioners prescribe antibiotics “just in case,” when they might not be needed, and that creates resistance.

“Antimicrobial stewardship aligns with Tufts at Tech’s mission, figuring out how to practice the best medicine while balancing financing,” says Sample. “Clinicians can feel comfortable knowing that if they chose to plate urine in-house, it would be similar to the reference standard. We can decide when antibiotics should be sent home and when we can wait. This helps all vets. Research allows us to make more informed decisions and lets us tailor which test we think will be best for patients.”

Sample’s writing and research skills have come a long way since she first took on the project. “The idea of research still makes me uncomfortable, but I’m starting to embrace that the more uncomfortable I feel, the more I’m growing. I have all these topics I feel passionate about, and the only way to make others aware is to publish what you’re doing.”

Grady comments on Sample’s role in the study, “Kayla has a lot of perseverance and grit when she is working towards a goal that will be directly helpful for her clients and patients. This was an example of how her commitment to high level patient care and antimicrobial stewardship pushed her to accomplish this very successful research project despite a host of other responsibilities during her residency.”

The study’s publication in JAVMA, with the highest readership of any veterinary journal, spreads awareness of the team’s findings to veterinary professionals across the country.

“I’m very honored that JAVMA accepted publication,” says Sample. “So much teamwork went into this research project, and many incredible people contributed. I’m proud to have this data published on what we’ve been doing for so many years.”