Isolation and Molecular Detection of Leptospira spp. from Rat Population in Selected Areas of Mymensingh District, Bangladesh

Leptospira, the aetiology of leptospirosis, is one of the most important zoonotic bacteria that affects humans and animals all over the world. It has many carriers, but rat is considered as the first primary host for leptospirosis. Despite the fact that this disease is common in many countries, its presence in Bangladesh is little recognized. From a socioeconomic standpoint, it poses a serious risk to our cattle industry's sustainability. Therefore, the purpose of this work was to identify and characterize Leptospira from the rat population using molecular, dark field, and culture techniques, as well as to investigate its pathogenicity. Eighty rat samples were aseptically taken from both urban and rural parts of the Mymensingh district, including rat kidney and urine samples. The EMJH medium was used to first allow each sample to grow. Dark field microscopy was used to identify the bacterial isolates, and PCR was used for molecular detection. In urban areas, 16 out of 40 rat samples were positive (40%) whereas 10 out of 40 rat samples in rural regions were positive (25%). In both regions, it was discovered that adult rat samples had more Leptospira than juvenile rat samples, while female rat samples were more positive than male rat samples. We draw the conclusion that Leptospira is present in Bangladeshi rat populations in both urban and rural locations. The high pathogenicity of some serovars of this bacterium raises concerns about the hazards to public health posed by rat transmission of leptospirosis, even if the reported infection incidence is minimal.