Free resource with detailed medical information on diseases and conditions, including those caused by micro-organisms.
Medical topics, drug information, news, commentary, procedures, examinations, quizzes, case studies, calculators, audio, video, podcasts, and more on all aspects of medicine and health. From a leading publisher of medical reference resources.
For any micro-organism of medical interest. Try the MeSH search (very top menu bar) and search by organism, then narrow by checking the options for topics like cytology, genetics, etc.
MEDLINE provides authoritative medical information on medicine, nursing, dentistry, veterinary medicine, the health care system, pre-clinical sciences, and much more. Created by the National Library of Medicine, MEDLINE uses MeSH (Medical Subject Headings) indexing with tree hierarchy, subheadings and explosion capabilities to search citations from over 4,800 current biomedical journals. Use instead of PubMed.
For all biological topics. Search for organisms or diseases and use the Subject option to the left of the results to narrow down the search.
The collection contains biological science related full-text articles, granular access to figures and tables within articles, and the entire range of bibliographic records from Biological Sciences database. Supporting over two dozen areas of expertise, Biological Sciences provides access to literature from serials, as well as conference proceedings, technical reports, monographs and selected books and patents.
Bergey's Manuals of Systematic Bacteriology by 
The Springer Index of Viruses by 
