The incidence of anaerobic bacteria in adult patients with chronic sinusitis: A prospective, single-centre microbiological study 1,2 3p 4 European Journal of EDIT URBAN ,MARIOGAJDACS and ATTILA TORKOS Microbiology and Immunology 1 Department of Public Health, Faculty of Medicine, University of Szeged, 6720 Szeged, Dom ter 10., Szeged, Hungary 10 (2020) 2, 107-114 2 Institute for Translational Medicine, Medical School, University of Pecs, 7624 Pecs, Szigeti ut 12., DOI: Pecs, Hungary 10.1556/1886.2020.00010 © 2020 The Authors 3 Department of Pharmacodynamics and Biopharmacy, Faculty of Pharmacy, University of Szeged, 6720 Szeged, Eotv€ os€ utca 6., Szeged, Hungary 4 Department of Oto-Rhino-Laryngology and Head-, Neck Surgery, Faculty of Medicine, University of Szeged, Szeged, Hungary Received: April 14, 2020 • Accepted: April 23, 2020 ORIGINAL RESEARCH Published online: June 5, 2020 PAPER ABSTRACT Introduction: Chronic sinusitis caused by anaerobes is a particular concern clinically, because many of the complications are associated with infections caused by these organisms. The aim of this study was to evaluate the incidence of anaerobic bacteria in chronic sinusitis in adults as a part of a prospective microbiological study. Materials and methods: Over a one-year period, aspirations of maxillary sinus secretions and/or ethmoid cavities were derived in n 5 79 adult patients with chronic sinusitis by endoscopy in a tertiary-care teaching hospital in Hungary. The qualitative and quantitative compositions of the total cultivable aerobic and anaerobic bacterial and fungal flora cultured on the samples were compared. Correct anaerobic species level identifications were carried out according to standard methods. Results: Bacteria were recovered for all of the 79 aspirates and the numbers of the significant cultured isolates (with colony forming units ≥103) were between 1 and 10. A total of 206 isolates, 106 anaerobic and 100 aerobic or facultative-anaerobic strains were isolated. The most common aerobic bacteria were Streptococcus pneumoniae (n 5 40), Haemo- philus influenzae (n 5 29), Moraxella catarrhalis (n 5 6), Staphylococcus aureus (n 5 7) and Streptococcus pyogenes (n 5 6). The anaerobic bacteria included black-pigmented Prevotella spp. and Porphyromonas spp. (n 5 27), Actinomyces spp. (n 5 13), Gram-positive anaerobic cocci (n 5 16), Fusobacterium spp. (n 5 19) and Cutibacterium acnes (n 5 8). Conclusions: This study il- lustratesthemicrobialdynamicsinwhichanaerobic and aerobic bacteria prevail and highlights the importance of obtaining cultures from patients with chronic sinusitis for guidance in selection of proper antimicrobial therapy. KEYWORDS anaerobic bacteria, chronic sinusitis, prospective, microbiology, Prevotella, Porphyromonas, otolaryngology INTRODUCTION Chronic sinusitis (CS) is an inflammatory disorder of the upper airways, which lasts longer *Corresponding author. than 12 weeks, often causing residual damage to the sinus mucosa, leading to long-term Tel.: þ36 62 341 330. E-mail: [email protected] symptoms (according the definition of the International Rhinosinusitis Advisory Board) [1, 2]. Based on literature findings, chronic sinusitis is almost always accompanied by concurrent nasal airway inflammation, and is often preceded by symptoms of rhinitis; thus, the term chronic rhinosinusitis (CRS) has evolved to more accurately describe this condition [1]. CRS is a multifactorial morbidity, in which the complex microbiome plays a pathogenic role [2]. It Unauthenticated | Downloaded 09/25/21 01:10 PM UTC 108 European Journal of Microbiology and Immunology 10 (2020) 2, 107-114 is a frequent bacterial infection among adults, affecting there were qualitative differences observed in the compo- approximately 5% of the Western population; the overall sition of the sinus microbiota among healthy and CRS- prevalence of CRS in the United States is 146/1,000 pop- patients [9]. Defining the nature of the role of the micro- ulation [3]. This involves nearly 30 million US adults biota in CRS is important because of the associated ther- annually, accounting for approximately 20 million office apeutic implications. Streptococcus pneumoniae, visits and 1.2 million hospital visits, making CRS more Haemophilus influenzae, Moraxella catarrhalis, Coryne- common than any other chronic condition, and for un- bacterium spp., Staphylococcus epidermidis and members known reasons, the incidence of this disease appears to be of the Enterobacterales order have been noted as the pre- increasing. According to the data from the US, the ratio of dominant aerobic pathogens recovered from patients with the recurrence is around 25% and the ratio of therapy- sinusitis; however, with the exception of Staphylococcus resistant cases of CRS is 10–15%. The European Position aureus, the association between any single species and CRS Paper on Rhinosinusitis and Nasal Polyps 2007 (EPOS is tenuous [10]. Many of these bacteria can interfere with 2007) found that the prevalence of CRS to be around 15– the overgrowth of potential other pathogens and may play 16% (this is in part, mostly speculative because of the non- a role in preventing the development of infections. Most uniformity in symptoms criteria and definitions), among cases of CRS are due to acute sinusitis that either is un- which, diagnosis by general practitioners was only around treated or does not respond to treatment [11]. However, 2–4% [4].TheEuropeanprevalencebytheEPOSand/ when sinusitis becomes chronic, these organisms are GA(2)LEN epidemiological study criteria was estimated to replaced by a variety of both aerobic and anaerobic bacteria be 10.9% overall and ranging between 5 and 15% in and it has been suggested that anaerobic bacteria play a different countries [4, 5]. Based on the results of the Na- significant role in the pathogenesis of CRS [12]. This may tional Ambulatory Medical Care Survey of the Centers for be the result of the selective pressure of antimicrobial agents, Disease Control and Prevention (CDC), rhinosinusitis is sometimes redundantly used in the management of acute the fifth most common cause for the prescription of anti- viral sinusitis, that enables resistant anaerobic organisms to biotics [6]. CRS begins with an inflammation of the mu- survive, and over time, for the development of conditions cous membranes in the sinuses, the air-filled passages appropriate for anaerobic growth, which include the reduc- around the nose and throat, leading to mucous stagnation tion in oxygen tension and an increase in acidity within the in the sinus, which forms a rich medium for the growth of sinus cavity [11, 12]. CRS caused by anaerobic bacteria is a various pathogens [1–3]. This early stage of sinusitis is particular concern clinically because many of very serious often caused by a viral infection, generally lasting up to 10 complications associated with this condition (spread of days, completely resolving in 99% of cases; however, a infection into the bones of the face, mucocele formation, small number of patients may develop a secondary acute osteomyelitis, meningitis and/or and brain abscess) are asso- bacterial infection, which is generally caused by aerobic ciated with these microorganisms [8]. Because of the special bacteria [1, 2]. The inflammation causes fluid build-up, techniques required for the collection, transport and culture eventually plugging the sinus cavity and preventing normal of anaerobes, the availability of reliable data on anaerobic mucus drainage. CRS may be caused by infections of the bacteria associated with CRS, especially in adult patients is upper respiratory tract — the nose, pharynx, sinuses and limited; however, based on various reports, anaerobic path- throat — but there are some non-infectious triggers, such ogens were recovered in 8–93% of cases [12–14]. The vari- as allergens, toxins and underlying genetic predisposition. ability in their recovery rate may be due to differences in the Approximately 10% of all sinusitis cases are the result of an methodologies used for sample preparation, transportation, odontogenic process, with several reports in the literature laboratory possibilities of culturing and identification, patient stating that up to 40% of all sinusitis cases may have an population, different geography and previous surgical and/or underlying dental pathology [7, 8]. The pathophysiology of antimicrobial therapy. this condition is still poorly understood, with multiple The evaluation of the pathogenic role of anaerobic bac- environmental, host and microbial factors being impli- teria in the acute exacerbation of CRS is of utmost impor- cated: allergies are a common cause, and anatomical tance. Establishing the correct microbiological diagnosis of problems such as a deviated nasal septum can bring on sinusitis is of primary importance, as it can serve as a guide chronic sinusitis, other suspected causes putative patho- to the choice of adequate antimicrobial therapy. Therefore, logical factors include changes in the microbiota, imbal- the aim of our study was to assess the microbial aetiology of ance of the local or systemic immune system, and the CRS in at a tertiary-care hospital in Hungary over a one-year presence of moulds or other fungi in the sinuses [9]. There long period. are a lot of the different studies clarifying some microbi- ological aspects of acute and chronic sinusitis, including its pathophysiology, epidemiology, role of bacterial biofilms MATERIALS AND METHODS and more recently, the microbiome of healthy and/or