TY - JOUR
T1 - Otopathogenic Pseudomonas aeruginosa enters and survives inside macrophages
AU - Mittal, Rahul
AU - Lisi, Christopher V.
AU - Kumari, Hansi
AU - Grati, M'hamed
AU - Blackwelder, Patricia
AU - Yan, Denise
AU - Jain, Chaitanya
AU - Mathee, Kalai
AU - Weckwerth, Paulo H.
AU - Liu, Xue Z.
N1 - Funding Information:
We are grateful to Dr. R. E. W. Hancock for kindly providing anti-OprF monoclonal antibody. We are grateful to April Mann for critical reading of the manuscript. We are thankful to Electron Microscopy Core Facility at Miller School of Medicine, University of Miami for assisting in electron microscopy experiments. We are also thankful to Dr. Marcia Boulina, University of Miami Analytical Imaging Core Facility, for help in confocal microscopy experiments. The research work in Dr. XL's laboratory is supported by grants R01 DC05575, R01 DC01246, and R01 DC012115 from the National Institutes of Health/National Institute on Deafness and Other Communication Disorders.
Publisher Copyright:
© 2016 Mittal, Lisi, Kumari, Grati, Blackwelder, Yan, Jain, Mathee, Weckwerth and Liu.
PY - 2016/11/18
Y1 - 2016/11/18
N2 - Otitis media (OM) is a broad term describing a group of infectious and inflammatory disorders of the middle ear. Despite antibiotic therapy, acute OM can progress to chronic suppurative otitis media (CSOM) characterized by ear drum perforation and purulent discharge. Pseudomonas aeruginosa is the most common pathogen associated with CSOM. Although, macrophages play an important role in innate immune responses but their role in the pathogenesis of P. aeruginosa-induced CSOM is not known. The objective of this study is to examine the interaction of P. aeruginosa with primary macrophages. We observed that P. aeruginosa enters and multiplies inside human and mouse primary macrophages. This bacterial entry in macrophages requires both microtubule and actin dependent processes. Transmission electron microscopy demonstrated that P. aeruginosa was present in membrane bound vesicles inside macrophages. Interestingly, deletion of oprF expression in P. aeruginosa abrogates its ability to survive inside macrophages. Our results suggest that otopathogenic P. aeruginosa entry and survival inside macrophages is OprF-dependent. The survival of bacteria inside macrophages will lead to evasion of killing and this lack of pathogen clearance by phagocytes contributes to the persistence of infection in CSOM. Understanding host-pathogen interaction will provide novel avenues to design effective treatment modalities against OM.
AB - Otitis media (OM) is a broad term describing a group of infectious and inflammatory disorders of the middle ear. Despite antibiotic therapy, acute OM can progress to chronic suppurative otitis media (CSOM) characterized by ear drum perforation and purulent discharge. Pseudomonas aeruginosa is the most common pathogen associated with CSOM. Although, macrophages play an important role in innate immune responses but their role in the pathogenesis of P. aeruginosa-induced CSOM is not known. The objective of this study is to examine the interaction of P. aeruginosa with primary macrophages. We observed that P. aeruginosa enters and multiplies inside human and mouse primary macrophages. This bacterial entry in macrophages requires both microtubule and actin dependent processes. Transmission electron microscopy demonstrated that P. aeruginosa was present in membrane bound vesicles inside macrophages. Interestingly, deletion of oprF expression in P. aeruginosa abrogates its ability to survive inside macrophages. Our results suggest that otopathogenic P. aeruginosa entry and survival inside macrophages is OprF-dependent. The survival of bacteria inside macrophages will lead to evasion of killing and this lack of pathogen clearance by phagocytes contributes to the persistence of infection in CSOM. Understanding host-pathogen interaction will provide novel avenues to design effective treatment modalities against OM.
KW - Cell viability
KW - Monocyte-derived macrophages
KW - Mouse bone marrow-derived macrophages
KW - Otopathogenic P. aeruginosa
UR - http://www.scopus.com/inward/record.url?scp=85006751091&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85006751091&partnerID=8YFLogxK
U2 - 10.3389/fmicb.2016.01828
DO - 10.3389/fmicb.2016.01828
M3 - Article
AN - SCOPUS:85006751091
VL - 7
JO - Frontiers in Microbiology
JF - Frontiers in Microbiology
SN - 1664-302X
IS - NOV
M1 - 1828
ER -