Molecular monitoring of Razi Institute NIH strain laboratory mice colony for infection with Leptospira interrogans bacteria

Leptospira interrogans is the cause of leptospirosis, a common disease among humans and animals. One of the most important recommendations of international associations concerned with laboratory animals, is the use of defined animals. Based on the recommendation of the FELASA, the diagnostic monitoring is required to evaluate the contamination of animals to different microbial agents. In this study, the prevalence of this bacteria was investigated in a colony of NIH strain laboratory mice of laboratory animal breeding unit at the Razi Institute in 1396.74 adult mice (in the range of 30-35g and age 6-8 weeks) were randomly selected from both sexes in breeding colony and 6 wild mice were selected by means of live traps from the outside of facility. After ethical euthanasia and autopsy, samples were taken from their kidney tissues and after preparation, the PCR method was performed using Leptospira interrogans specific primers. Designing and preparing the positive control was carried out using plasmid (pGEM -T easy vector) transformation containing the pathogenic of Leptospira interrogans gene (LipL32) in E.coli for gene amplification and extraction. No positive cases were observed from the examined samples. According to FELASA instructions, it can be concluded that with 99.9% confidence, the Leptospira interrogans infection in breeding salons of Razi Institute NIH mice was discarded.