Intracellular Staphylococcus aureus: the Trojan horse of recalcitrant chronic rhinosinusitis?

Abstract

Clinical and microbiological relapse of disease following ESS is significantly associated with intracellular S. aureus. Evidence suggests that this disease association is independent to surface biofilm status. Intracellular bacteria should be taken into consideration when designing novel treatment strategies to lessen the chance of reinfection.

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.…”

“…Nasal polyps were 1 of the first tissue types to be identified to have ICSA, 4 although they have been subsequently demonstrated in nonpolypoid mucosa of CRSsNP patients. 8 Corriveau et al 9 showed no difference in ICSA prevalence between CRSsNP, CRSwNP, and control groups, whereas studies by Tan et al 10 showed that ICSA was most prevalent in patients with CRSwNP. Interestingly, a subsequent study by Kim et al 8 reported a greater percentage of ICSA in CRSsNP although no statistically significant difference was observed.…”

“…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.…”

“…A similar pattern was also observed in other studies. 10,20 The lack of association can be partly because S. aureus that resides intracellularly is known to switch to a SCV phenotype, 7 which has proven to be more difficult to culture using traditional agar techniques. These findings indicate that the result of conventional swab culture remains a poor predictor for the presence of S. aureus intracellularly.…”

“…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). 10 One limitation of the study was the lack of use of validated patient reported outcome measures (PROMs). The purpose of our study was to address this limitation as well as to investigate whether the presence of ICSA had any additional effect on inflammation and fibrosis.…”