Microbiological Monitoring Analysis of Laboratory Rats and Mice from Vendors: Department of Laboratory Animal Science of Fudan University as an Example

Abstract

Objective Conduct routine microbiological monitoring of laboratory rats and mice from vendors to provide an important basis for the scientific management of laboratory animal facility and ensure the reliability of relevant experimental data obtained from laboratory animals. Methods Taking the Department of Laboratory Animal Science of Fudan University as an example, between April 2021 and April 2023, rats and mice purchased from 7 vendors were sampled for microbiological quality according to the principle of simple random sampling on the arrival days of animal delivery. Then, surveillance tests were conducted to examine the microbiological contaminations according to the national standards of SPF laboratory animals. Results The total qualified rate was 80.36%, with 52.63% in SD rat, 82.76% in inbred mice, 86.67% in outbred mice and 86.36% in immunodeficient mice in details. The most frequent bacteria isolated were Staphylococcus aureus, Pseudomonas aeruginosa, Klebsilla pneumoniae and Rodentibacter heylii, and their detection rates were 10.76%, 3.16%, 2.53% and 0.63%, respectively. Serological assays demonstrated the highest prevalence for virus was Sendai virus, and the detection rate was 2.53%. In addition to the pathogens those must be excluded from SPF rodents, Entamoeba muris and Enterobacter spp. were also detected in inbred mice, and Klebsiella oxytoca was detected in immunodeficient mice, with the detection rates of 1.15%, 2.30% and 4.55%, respectively. Conclusion There are certain incidences of pathogen infections in laboratory rats and mice from vendors, and an efficient microbiological monitoring of laboratory animals should be implemented in animal facilities, in order to eliminate pathogen infections in laboratory animals, which is required for improving the accuracy of research results and protecting the occupational health of laboratory animal practitioners as well.

Keywords

• microbiology
• monitoring
• vendor
• laboratory animal quality
• rat
• mouse