Conclusion
To our knowledge, this work is the first study reporting H2S as a novel potential virulence determinant ofM. bovis isolated in Egypt. Due to the occurrence of fluoroquinolone resistance in M. bovis as well as increased resistance to other antibiotics, susceptibility testing of this pathogen should be implemented as a routine procedure and as a part of the diagnostic process. This study also draws attention on the increasing number of drug-resistant M. bovis , in particular in Egypt asin Europe and worldwide. The data obtained in the present study shows the weak presence of the vsp  gene and the conjunctive absence of theuvr C gene in all field isolates tested provides evidence that the serological tests based on Vsp antigens and molecular identification depending on the uvr C gene used for cattle is not appropriate for testing samples recovered from camels. In addition, these potential virulence factors could not be used as candidates for drug therapy and vaccine design.