Quantification ofBrucella abortuspopulation structure in a natural host

• DOI: 10.1073/pnas.2023500118
• Publication Date: 2021-03-09T20:51:00Z
• Authors: Aretha Fiebig; Catherine E. Vrentas; Thien Le; Marianne Huebner; Paola M. Boggiatto; Steven C. Olsen; Sean Crosson
• Keywords: 0301 basic medicine; 2. Zero hunger; Virulence; Brucella abortus; Cattle Diseases; 04 agricultural and veterinary sciences; Brucellosis; 0403 veterinary science; 03 medical and health sciences; Animals; Cattle; Female; Lymph Nodes

SignificanceUnderstanding microbial population dynamics during infection has important implications for disease management, transmission, and pathogen evolution. A quantitative analysis of microbial population structure requires the ability to track individual strains. We used a pool of individually barcoded strains to measure changes inBrucella abortuspopulation structure during infection of bovine hosts via the ocular conjunctiva, a natural route of entry. Cattle exert a severe bottleneck on the bacterial population entering through the conjunctival mucosa such that individual cells have a 0.0001 probability of colonizing a local draining lymph node. The populations in lymph nodes, even on different sides of the same animal, are distinct and dominated by a small number of highly abundant, spatially distinct clones.