From the standpoint of medical bacteriology, micro-organisms may be divided into two large groups, namely, pathogenic and nonpathogenic bacteria and viruses. In many instances it is possible to prove the pathogenicity of a micro-organism by fulfilling all or some of Koch's postulates. On the other hand, it is a recognized fact that so-called nonpathogenic bacteria may occasionally cause disease in man and in animals. It is also established beyond doubt that certain bacterial species may be nonpathogenic at one particular site, for instance, in the intestinal tract or on the skin, and may become pathogenic when present in other organs and organ systems.
Bacillus alcaligenes is generally considered to be nonpathogenic for man. There are available, however, a number of reports indicating that this species may cause infections in man. We should like to present observations on a case of Bacillus alcaligenes bacteremia complicating diabetes mellitus.
REPORT OF A CASE