Survival of Bacterial Biofilms within Neutrophil Extracellular Traps Promotes Nontypeable Haemophilus influenzae Persistence in the Chinchilla Model for Otitis MediaHong W. · Juneau R.A. · Pang B. · Swords W.E.
Department of Microbiology and Immunology, Wake Forest University Health Sciences, Winston-Salem, N.C., USA
Nontypeable Haemophilus influenzae (NTHi) is a leading cause of acute and chronic otitis media, which are a major public health problem worldwide. The persistence of NTHi during chronic and recurrent otitis media infections involves multicellular biofilm communities formed within the middle-ear chamber. Bacterial biofilms resist immune clearance and antibiotic therapy due in part to encasement within a polymeric matrix. In this study, the contribution of biofilms to bacterial persistence in vivo and composition of the NTHi biofilm matrix during experimental otitis media were investigated. The presence of biofilms within the chinchilla middle-ear chamber was significantly correlated with increased bacterial load in middle-ear effusions and tissue. Examination of thin sections revealed polymorphonuclear cells within a DNA lattice containing elastase and histones, which is consistent with the definition of neutrophil extracellular traps. Viable multicellular biofilm communities with biofilm phenotypes were found within the DNA lattice throughout the biofilm. Further, NTHi was resistant to both phagocytic and extracellular neutrophil killing in vitro by means of lipooligosaccharide moieties that promote biofilm formation. These data support the conclusion that NTHi subverts neutrophil extracellular traps to persist in vivo. These data also indicate that a more inclusive definition for biofilms may be warranted.
Dr. W. Edward Swords
Department of Microbiology and Immunology
Wake Forest University Health Sciences, 5101A Gray Building
1000 Medical Center Boulevard, Winston-Salem, NC 27157 (USA)
Tel. +1 336 713 5049, Fax +1 336 716 9928, E-Mail firstname.lastname@example.org
W.H. and R.A.J. contributed equally to this work.
Received: September 10, 2008
Accepted after revision: November 24, 2008
Published online: February 27, 2009
Number of Print Pages : 10
Number of Figures : 5, Number of Tables : 1, Number of References : 42
Journal of Innate Immunity
Vol. 1, No. 3, Year 2009 (Cover Date: April 2009)
Journal Editor: Herwald H. (Lund), Egesten A. (Lund)
ISSN: 1662-811X (Print), eISSN: 1662-8128 (Online)
For additional information: http://www.karger.com/JIN