In_depth_analysis_of_Haemolytic_Escherichia_coli_from__human_urinary_tract_infections__rectal_swabs_from_humans__pigs__roe_deer__martens__raccoons__red_foxes_and_mallard_ducks

We isolated 81 haemolytic E. coli from: human urinary tract infections, rectal swabs from humans, pigs, roe deer, martens, raccoons, red foxes and mallard ducks. We have developed an automated microscopy-based system named VideoScan for monitoring the ability of haemolytic E. coli isolates to exfoliate cells. Using VideoScan, we have determined the cell line toxicity for aforementioned haemolytic E. coli isolates. This analysis was performed with use of four different cell lines: LoVo (human colon adenocarcinoma cell line) and 5637 (human bladder carcinoma cell line) and IPEC-J2 (intestinal porcine epithelial cells) and PK-15 (porcine kidney epithelial cells). Testing for cytotoxicity, we found a diverse patterns of our isolates against the four cell lines. We observed that human and porcine E. coli destroyed intestinal more than urothelial cell monolayers. E. coli from wild animals were more potent in destroying cell monolayers compared to human or porcine E. coli. Having the isolates and cytotoxicity data we would like to investigate factors responsible for different cell line exfoliation phenotypes. Therefore we would like to carry out whole genome sequencing of 81 E. coli isolates. This would allow us to: identify haemolysin types in our collection of isolates; analyse influence of single nucleotide polymorphism in haemolysin operon on cytotoxicity; identify new genetic loci involved in regulation of haemolysin expression; determine the virulence factors associated with haemolytic E. coli and pathotyping of investigated isolates; comparison of haemolytic E. coli isolated from various hosts; comparison of haemolytic and non-haemolytic E. coli genomes. This work will allow us to better understand role of haemolysin in E. coli pathogenesis and will provide useful information about diversity of haemolytic E. coli isolated from various hosts.