Nur Abdul Kader

Leptospirosis, a major issue in veterinary medicine and public health, is a bacterial systemic disease caused by pathogenic spirochetes of the genus Leptospira. This infectious disease affects a wide range of animal species, including humans, indicating its widespread impact. Leptospires are highly diverse, with over 20 species, which are divided into over 300 serovars and more than 24 serogroups, which complicates the pathogenicity of the disease. Leptospirosis causes economic losses in livestock, which has larger consequences for food security and farming communities. Leptospirosis develops differently in livestock and wildlife, with small mammals, especially rodents, playing a crucial role as maintenance hosts. Effective management requires surveillance systems that employ serological, molecular, and cultural approaches. The interdependence of human and animal health emphasizes the need for a worldwide One Health approach that prioritizes collaborative work, research, and targeted interventions to address the multifaceted challenges of leptospirosis in a unified manner.

Escherichia albertii and Escherichia fergusonii are recognized as emerging pathogens with zoonotic potential. Despite their increasing importance, there is a paucity of data on the cytotoxicity of these two pathogens. Therefore, in the present study, we investigated the cytotoxic potentials of the cell-free supernatants from 10 E. albertii and 15 E. fergusonii isolates for their cytotoxic effects on four different cell lines (CHO, Vero, HeLa, and MDCK). All E. albertii isolates (100%) and all but one E. fergusonii (93.33%) were cytotoxic. E. albertii isolates produced similar cytotoxicity titres across the cell lines, whereas the Vero cell was found to be the most sensitive to toxins produced by E. fergusonii (p < 0.05), followed by HeLa and CHO cells. MDCK was the least sensitive cell line to E. fergusonii toxins (p < 0.05). PCR detection of cytotoxicity-associated genes (cdtB, stx1, and stx2) indicated uniform possession of cdtB gene by all E. albertii isolates, while stx1 and stx2 genes were harboured neither by E. albertii, nor E. fergusonii. Taken together, our results provided experimental evidence of the cytotoxic effects of these two emerging pathogens, and Vero cells were identified as an optimal candidate to study the cytotoxic effects of E. albertii and E. fergusonii.