In the early twentieth century, scientists at the Pasteur Institute and its colonial affiliates developed a historically specific form of bacteriological technoscience, which abstracted the human–microbe relationship from its environmental and social context, and created a model for public health governance that operated at the scale of the empire, rather than at the level of individual colonies or regions. Using a case study of tuberculosis management, this article argues that the success of the Pastorian model relied on its technopolitical vision of a universal model of managing human–microbe relations, while, in reality, exploiting precisely those fissures created by the uneven political and scientific landscape of the colonial and scientific world in which it operated. Pastorian bacteriology helped imperial administrators to imagine a globe-spanning, standardized empire, while restricting public health governance to technological innovations, rather than a proposal for social hygiene that would have expanded labour and associational rights for subject populations.