Biannual and Quarterly Comparison Analysis of Agglutinating Antibody Kinetics on a Subcohort of Individuals Exposed to Leptospira interrogans in Salvador, Brazil

Infection and re-infection of Leptospira spp. in stray dogs and cats from Bogota, Colombia

Background and Aim

Leptospirosis is a re-emerging zoonosis that is under-reported in tropical countries, and canines can be a potential reservoir of the disease. The objective of this study was to diagnose Leptospira spp. that is actively infected and re-infected in stray dogs and cats from Bogota, D.C., Colombia.

Materials and Methods

A sample of 200 animals, including dogs and cats from the animal protection programs of Bogota, Colombia, were used in this study. Blood was collected from these animals for serum and DNA analysis. Conventional polymerase chain reaction (PCR) was performed using the 16s rRNA primer set, and higher-quality amplification products were sequenced by Sanger. For serodiagnosis, a group of PCR-positive samples was tested using the microagglutination test (MAT).

Results

The overall PCR positivity of stray dogs and cats was 56%, 52.9%, and 65.3% in dogs and cats, respectively. The MAT seropositivity was 77.3%, and only dogs showed titers higher than 1:400. Canicola, Icterohaemorrhagiae, Pomona, Hardjo Prajitno, and Canicola and Hardjo prajitno were the serogroups associated with dogs and cats, respectively. Phylogenetic analysis revealed that the strains belonging to Leptospira interrogans serovars related to isolated samples of American, European, and Asian bats (Myotis myotis), dogs, and bovines of American origin.

Conclusion

These results showed that stray dogs and cats were previously exposed to different serovars of Leptospira spp. and re-infected with other serovars that actively participated in the transmission cycle. These findings highlight the importance of actively diagnosing infectious animals to design effective intervention strategies.