Multi-Centered Field Evaluation of a Salmonella spp. Point-of-Care PCR Assay Using Equine Feces and Environmental Samples.

The research article is about an evaluation of a novel point-of-care (POC) PCR testing method for detecting Salmonella spp. in equine feces and environmental samples. The study shows strong agreement with traditional qPCR assays and short turn-around time, making it a practical solution for rapid diagnosis of salmonellosis in a hospital setting.

Background and Purpose of the Study

• The research study sought to test and evaluate a novel Point-of-Care (POC) PCR assay designed to detect the presence of Salmonella spp. in both feces and environmental samples. The ultimate goal was to provide equine veterinarians with an accurate POC PCR assay to support timely and efficient diagnosis of salmonellosis and monitor environmental risk factors for nosocomial (hospital-acquired) infections.

Methods and Procedure

• A total of 143 fecal samples and 132 environmental samples were collected for testing. The samples were first inoculated into a mixture called selenite broth and incubated for a period spread between 18 to 24 hours.
• Then, the researchers introduced the POC PCR assay, which involved mixing a specified amount of the selenite broth with a PCR reaction mix. This solution was then pipetted into a microfluidic test card, which specifically targets certain gene markers of Salmonella enterica, a bacterium that causes salmonellosis.
• For comparison purposes, another method, known as the qPCR analysis, was also performed on the samples. It involved the purification of DNA from the selenite broth and subsequential testing for Salmonella spp., again targeting the specific invA gene.

Findings and Conclusion

• The results of the two testing methods were then compared. It was found that the agreement between the POC PCR Salmonella spp. assay and qPCR assay was 88.1% for fecal samples and 97.0% for environmental samples. This high level of agreement suggests that the POC PCR assay is an accurate and reliable method for the detection of Salmonella spp. in samples.
• The study showed that POC PCR assay holds considerable promise as a rapid and immediate diagnostic tool for equine veterinarians. This tool could potentially allow for the immediate detection of Salmonella spp. in a hospital setting, eliminating the need to send samples to an off-site veterinary diagnostic laboratory.
• Overall, the successful implementation of this POC PCR assay could significantly enhance the diagnostic capabilities of equine veterinarians, aiding in the timely diagnosis of salmonellosis and monitoring of environmental factors to reduce the risk of nosocomial infections.