[The protagonist microbe: notes on the communication of bacteriology in the Gazeta Médica da Bahia journal, nineteenth century]. / O micróbio protagonista: notas sobre a divulgação da bacteriologia na Gazeta Médica da Bahia, século XIX.

Germ theory, derived particularly from the work of Louis Pasteur and Robert Koch, shook the foundations of medical knowledge in the second half of the nineteenth century and triggered a revolution in the "art of healing." The search for specific microbes for diseases guided the investigations of the researchers converted to the Pasteurian tenets. This paper aims to show what role the Gazeta Médica da Bahia journal played in spreading knowledge about bacteriology to the medical communities in Bahia and throughout Brazil. Some works and reflections by the newspaper's authors at the time are presented, as are some of the controversies that help depict the way germ theory was divulged in Brazil throughout the nineteenth century.