Related Experiment Video
Updated: Aug 9, 2026
Quasi-metagenomic Analysis of Salmonella from Food and Environmental Samples
Published on: October 25, 2018
Plasmid profile analysis of salmonellae in a large-animal hospital
Abstract:
The plasmid profiles of salmonellae isolated from the patients and environment of the Purdue Large Animal Hospital were used as markers to identify strains and to assess the impact of improvements in hospital operation on nosocomial salmonellosis. Plasmid profile analysis proved to be more sensitive than either serotyping or antimicrobial susceptibility testing in identifying Salmonella isolates. During June and July 1983, 29 of 34 salmonellae isolated were one of three strains with distinct plasmid profiles: one S. typhimurium var. Copenhagen, and two S. muenchen. Each of these strains was isolated from at least one patient and two environmental sites, suggesting the possibility that infections were hospital-acquired. Patient and environmental sampling was repeated in June and July 1984, after improvements had been made in hospital traffic flow and sanitation. In contrast to 1983, only seven isolates, representing six strains not seen previously, were obtained in 1984. None of these strains was isolated from both patient and environmental sources. The results indicate that the high incidence of clinical salmonellosis in 1983 was largely due to nosocomial infections. The decrease in the incidence of salmonellosis and the absence of the 1983 strains from samples taken in 1984 were presumed to be due to improvements made in hospital operation. This study demonstrates the value of plasmid analysis in monitoring nosocomial salmonellosis in a veterinary hospital.
Insights
Plasmid profile analysis identified hospital-acquired salmonellosis in veterinary patients. Improvements in hospital sanitation and traffic flow significantly reduced salmonella infections, demonstrating the value of plasmid analysis for monitoring.
Area of Science:
- Veterinary Medicine
- Microbiology
- Infectious Diseases
Background:
- Nosocomial salmonellosis is a significant concern in veterinary hospitals.
- Identifying the sources and transmission routes of Salmonella is crucial for control.
Purpose of the Study:
- To assess the impact of hospital operational improvements on nosocomial salmonellosis.
- To evaluate the utility of plasmid profile analysis in monitoring Salmonella strains.
Main Methods:
- Plasmid profiles of Salmonella isolates from patients and the hospital environment were analyzed.
- Strain identification was compared between plasmid profiling, serotyping, and antimicrobial susceptibility testing.
- Sampling was conducted before and after implementing hospital operational changes.
Main Results:
- Plasmid profile analysis was more sensitive than serotyping or antimicrobial susceptibility testing for identifying Salmonella isolates.
- In 1983, three distinct Salmonella strains were linked to both patients and environmental sites, indicating hospital-acquired infections.
- Following improvements in 1984, a significant decrease in Salmonella incidence was observed, with no recurring strains found in both patient and environmental samples.
Conclusions:
- The high incidence of salmonellosis in 1983 was primarily due to nosocomial infections.
- Improvements in hospital operations effectively reduced the incidence of salmonellosis.
- Plasmid analysis is a valuable tool for monitoring and controlling nosocomial salmonellosis in veterinary settings.
