GRE scores? Based in the US? How good were your LORs?
I am going to assume USA. Right now, everyone wants to go into microbiology. Recruitment depends on funding. A good strategy for next year is to focus on schools that are R1 with T grants from NIAID or large center grants. Truth is no productive PI wants to take on generally useless grad students unless there is support coming in at the departmental level. Hence, look for departments that can bring in the $$ and support grad student training. Avoid schools that require you to TA, which is a sign of no funding.