Survey Of Genes Of Escherichia Coli Causing Bovine Mastitis With DNA Microarrays
Background: Mastitis in dairy cattle is a common ailment worldwide. A cause of mastitis can be bacteria such as Escherichia coli. Mastitis is not a deadly ailment and sometimes the dairy cows show no symptoms but if certain virulence genes are present in the bacteria that cause the mastitis, the bacteria can be transmitted to humans and cause severe diseases. The potential presence of enterohemorrhagic Escherichia coli (EHEC) in particular would be a major concern for human health.Aim: The aim for this study was to analyze the presence of virulence genes known to be present in E.coli strains isolated from dairy cows with mastitis in Sweden.Method: A Qiagen BIO ROBOT EZ1 was used to purify DNA from 90 bacterial cultures. A panel of virulence genes were amplified and biotinylated from the purified DNA by PCR and an E.coli based DNA microarray was used to detect presumed virulence genes in E.coli.Result: There were no samples that had all the genes traditionally used to classify E.coli as EHEC or potential EHEC. 63 samples were analyzed without any problems but 27 samples were not fully analyzed.Conclusion: The DNA based microarray proved to be a reliable method to detect genes from pathogenic bacteria but it needed high concentration of purified DNA which was not always easy to obtain. There were some samples in this study that contained virulence genes.