The multiplicity of Staphylococcus aureus in chronic rhinosinusitis: Correlating surface biofilm and intracellular residence

Abstract

Objectives/Hypothesis:The biofilm paradigm of chronic rhinosinusitis (CRS) is increasingly understood to play a key role in the pathophysiology of this disease. The role of intracellular infection of sinonasal epithelial cells has been suggested as a potential reservoir of pathogenic organisms that can lead to recalcitrant disease despite maximal medical and surgical treatment. Could a surface biofilm play a role in allowing intracellular infection to occur, and what are the factors associated with potential intracellular infections? The aim of this study was to investigate these questions.Study Design:A prospective study including 36 CRS patients undergoing endoscopic sinus surgery and five control patients undergoing endonasal pituitary surgery.Methods:Sinonasal mucosa harvested at the time of surgery was examined with a Staphylococcus aureus fluorescence in situ hybridization probe and propodium iodide counterstain using the confocal scanning laser microscope for both biofilm status and evidence of intracellular organisms.Results:Intracellular S aureus was identified in 20/36 (56%) CRS patients compared to 0/8 (0%) control patients. CRS patients with intracellular infection were significantly more likely to harbor surface biofilm (20/20, P = .0014) and have a S aureus‐positive culture swab (12/20, P = .0485).Conclusions:This study gives further evidence supporting a role of intracellular S aureus in CRS. In all cases intracellular infection was associated with surface biofilm, suggesting a potential relationship between the two. Further work is required to delineate the true mechanisms of intracellular persistence and also the role that it plays in the recalcitrant nature of CRS. Laryngoscope, 2012

International Consensus Statement on Allergy and Rhinology: Rhinosinusitis

“…331 The precise relationship between biofilm formation and CRS pathogenesis is poorly understood. However, biofilm presence in the sinonasal tract is correlated with concurrent CRS, 332 and outcomes after ESS are worse in patients who have biofilm colonization. 333 Specifically, endpoints of postoperative symptoms, ongoing inflammation, and recurrent infections were all increased in biofilm-positive surgery patients.…”

Association of intracellular Staphylococcus aureus with prognosis in chronic rhinosinusitis

“…4,5,8,10,20 These have consistently observed ICSA in CRS patients with differing prevalence in the different CRS patient populations. These discrepancies can be attributed to differences in ICSA detection strategies, the definition of CRS phenotypes, and the use of CRS patient tissue types.…”

“…17,18 Presence of ICSA in healthy controls has also been reported in previous studies ranging from 0% to 33%. 5,[8][9][10]19 The true prevalence of ICSA in healthy individuals remains unknown as there has been no large-scale population study performed to address this because the detection is costly and laborious regardless of the choice of techniques.…”

“…5,8,9 A cross-sectional study performed by Tan et al 5 demonstrated an association between ICSA and surface biofilm in CRS with nasal polyps (CRSwNP) patients as well as a greater number of revision surgeries. A subsequent study by the same authors found the presence of ICSA in CRS patients was associated with early clinical and microbiological failure post-endoscopic sinus surgery (ESS).…”

“…1,2 S. aureus is traditionally thought to be an extracellular pathogen with the potential to cause severe diseases such as cellulitis, endocarditis, and osteomyelitis. 3 Recently, however, S. aureus has also been shown to have the capacity to invade the mucosa in CRS patients and has been identified both within the epithelium 4,5 and submucosal tissue. 6 In 2005, Clement et al 4 demonstrated intracellular S. aureus (ICSA) in nasal epithelial cells, myofibroblastic cells, as well as phagocytes within nasal polyp specimens of CRS patients.…”