No Genomic Signatures Were Found in Escherichia coli Isolates from Camels With or Without Clinical Endometritis

Clinical endometritis is a leading cause of infertility in she-camels. We commonly isolate <i>E. coli</i> from camel uteri with and without endometritis during our routine diagnosis of conception failure. From an epidemiological standpoint, it is critical to know if certain <i>E. coli</i> genotypes and virulence factors are specifically associated with endometritis. Thus, we aimed to compare the abundance of virulence elements and genotypes in uterine <i>E. coli</i> from camels with and without endometritis and understand their evolution. For this investigation, we retrieved data from the genomes of 28 <i>E. coli</i> isolates from humans, cats, dogs, horses, cows, and birds and 14 sequenced genomes of camel uterine <i>E. coli</i> isolates. We found no specific <i>E. coli</i> genotype or virulence factor associated with endometritis. Instead, multiple genotypes and high genomic diversity were observed. Moreover, horizontal gene transfer driven by genomic islands and plasmids contributed to the genetic diversity of the isolates, resulting in the acquisition of virulence genes, metabolic characteristics, and antibiotic resistance determinants to trimethoprim, sulfonamide, streptomycin, and tetracycline. Additionally, the phylogenetic position of the <i>E. coli</i> isolates from camel uteri suggests that they originated from intestinal strains. In conclusion, there was no evidence of <i>E. coli</i> specialization, and <i>E. coli</i> alone may not be able to develop endometritis, as other factors are required. Also, we elucidated the mechanism behind the diversity of the gene repertoire of <i>E. coli</i> isolated from camel uteri. These findings provide insight into the evolutionary origins of <i>E. coli</i> isolates from camel uteri.