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Air pollution induces Staphylococcus aureus USA300 respiratory tract colonization mediated by specific bacterial genetic responses involving the global virulence gene regulators Agr and Sae.

Published version
Peer-reviewed

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Authors

Hussey, Shane JK 
Corscadden, Louise 
Purser, Lillie 
Hall, Andie 

Abstract

Exposure to particulate matter (PM), a major component of air pollution, is associated with exacerbation of chronic respiratory disease, and infectious diseases such as community-acquired pneumonia. Although PM can cause adverse health effects through direct damage to host cells, our previous study showed that PM can also impact bacterial behaviour by promoting in vivo colonization. In this study we describe the genetic mechanisms involved in the bacterial response to exposure to black carbon (BC), a constituent of PM found in most sources of air pollution. We show that Staphylococcus aureus strain USA300 LAC grown in BC prior to inoculation showed increased murine respiratory tract colonization and pulmonary invasion in vivo, as well as adhesion and invasion of human epithelial cells in vitro. Global transcriptional analysis showed that BC has a widespread effect on S. aureus transcriptional responses, altering the regulation of the major virulence gene regulators Sae and Agr and causing increased expression of genes encoding toxins, proteases and immune evasion factors. Together these data describe a previously unrecognized causative mechanism of air pollution-associated infection, in that exposure to BC can increase bacterial colonization and virulence factor expression by acting directly on the bacterium rather than via the host.

Description

Funder: MRC DTP IMPACT studentship


Funder: National Centre for Atmospheric Science Air Pollution Science Training Studentship Programme

Keywords

Air Pollution, Animals, Bacterial Proteins, Carbon, Gene Expression Regulation, Bacterial, Humans, Mice, Particulate Matter, Peptide Hydrolases, Respiratory System, Staphylococcal Infections, Staphylococcus aureus, Virulence, Virulence Factors

Journal Title

Environ Microbiol

Conference Name

Journal ISSN

1462-2912
1462-2920

Volume Title

Publisher

Wiley
Sponsorship
Leverhulme Trust (RPG‐2015‐183)
Network on Antimicrobial Resistance in Staphylococcus aureus (NARSA) Program (HHSN272200700055C)