So Fields Virology (two volume set) is an extremely good source to knowing the exact molecular details and pathogenesis of various viruses (this textbook is usually used for graduate students since the material is extremely complex). However when it comes to a finding a textbook that can be used for bacteria in the same manner its very hard to state which text is better then the next time (since various authors go into more detail than others or leave out information for various species). Also depending on what you want to get out of finding a textbook like this also plays a role but what I recommend is going to the ASCP certification homepage and clicking on the certification for Microbiology. When you click this a link on the right hand side appears in which is book references to help those study for the certification exam should buy, read and study from. There is roughly 20 fish books they recommend which contain various textbooks with ample amount of information in bacteria such as medical microbiology diagnostic texts, etc.