i am relocated to UK on spouse visa, i was working as an assistant professor in Microbiology at Pakistan, i have degrees of DVM and MSc (hons) in vet microbiology, now i am interested in PhD studentship in UK.. i will be highly obliged if any one here to guide in this contest.. thanks

Well there isn't a guide as such.. If you want to do a PhD then the best thing to do is to start searching for projects and contact potential supervisors, then start applying. There are lots of universities doing work on veterinary realted microbiology and so there will be lots of things out there to apply for. One problem I foresee is that you are not a UK/EU citizen so getting funding could be difficult.

Well you could have a look at the advertisements on this website. There's also jobs.ac.uk to try. One other possibility is to join the mailing lists of societies related to microbiology as a number of PhD posts get emailed around.