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Introduction

Resident bacterial flora have been isolated from uninflamed sinuses in several studies , but whether they have a pathogenic role or not remains to be seen. According to the National Ambulatory Medical Care Survey data, sinusitis is the fifth most common diagnosis for which antibiotics are prescribed . While there is a general consensus on the pathogenic microbes responsible for acute sinusitis, the role of microbes in chronic rhinosinusitis is still debated . In both polypoid and non-polypoid chronic rhinosinusitis, the role of microbes and their influence on the disease’s onset and recurrence remain unclear. The bacteria most commonly isolated in cases of chronic rhinosinusitis with no nasal polyposis are Staphylococcus aureus , coagulase negative staphylococci, and Gram-negative rods (especially Pseudomonas aeruginosa ) , but several studies have shown that anaerobic bacteria were also being isolated more and more often, especially Prevotella spp and Peptostreptococcus spp . It has been suggested that these different pictures emerging on isolating anaerobic bacteria related to microbe selection after the administration of antibiotics, to the development of conditions appropriate for anaerobic growth in the nasal mucosa, and to different sample collection methods . The exact role of these microbes in the pathogenesis of chronic sinusitis also remains to be clarified. A review of the available literature supports the hypothesis that the microbes in the maxillary sinus of patients with chronic sinusitis and polyposis do not differ from those in patients with chronic sinusitis but no polyposis , although anaerobic bacteria were isolated more frequently in the former in some series . Niederfuhr et al. found no significant differences in the bacteriological features of ethmoidal biopsy specimens from patients with chronic rhinosinusitis with and without nasal polyps.

Burkholderia cepacia was first described as a plant pathogen causing sour skin of onion , and given the name of Pseudomonas cepacia . It has gone from a single species to become a complex ( Burkholderia cepacia complex [Bcc]) comprising at least 17 closely-related species, or genomovars, that can only be classified properly by means of a combination of different molecular diagnostic procedures. Published and unpublished results of recA sequencing and multilocus sequence analyses indicate that a considerable number of Bcc species remain to be named . Bcc strains are remarkably adaptable to diverse lifestyles, and can also behave as opportunistic pathogens in immunocompromised patients . Bcc bacteria are endowed with an extraordinary metabolic diversity and emerged in the 1980s as life-threatening, difficult-to-treat pathogens among patients with cystic fibrosis. More recently, these bacteria became recognized as a threat to hospitalized patients suffering from other diseases too, and oncological patients in particular . Bcc has also contaminated many pharmaceutical end-products (including oxymetazoline hydrochloride nasal spray ) and environments where pharmaceuticals are manufactured . One of the main problems associated with Bcc lies in their intrinsic resistance to most clinically-available antimicrobials, including aminoglycosides, quinolones, polymyxins, and β -lactams. The multi-resistance of Bcc bacteria seems to be due to various efflux pumps that efficiently remove antibiotics from the cell, to the antibiotics having less contact with the bacteria’s cell surface due to their ability to form biofilms, and to changes in the cell envelope that reduce the membrane’s permeability to the antibiotic .

In the present prospective study, we investigated the microbes isolated in nasal swabs from a cohort of 34 patients with polypoid and non-polypoid chronic rhinosinusitis before and after functional endoscopic sinonasal surgery (FESS). None of the patients enrolled had cystic fibrosis. Bcc had already been isolated in sinonasal polyposis , but this is the first report of its isolation in chronic rhinosinusitis patients with no nasal polyposis.