Characterization of fungi in chronic rhinosinusitis using polymerase chain reaction and sequencing

Estimated burden of serious human fungal diseases in Turkey

The current number of fungal infections occurring each year in Turkey is unknown. We estimated the burden of serious human fungal diseases based on the population at risk, existing epidemiological data from 1920 to 2017 and modelling previously described by the LIFE program (http://www.LIFE-worldwide.org). Among the population of Turkey (80.8 million in 2017), approximately 1 785 811 (2.21%) people are estimated to suffer from a serious fungal infection each year. The model used predicts high prevalences of allergic fungal rhinosinusitis episodes (312 994 cases) (392/100 000), of severe asthma with fungal sensitisation (42 989 cases) (53.20 cases/100 000 adults per year), of allergic bronchopulmonary aspergillosis (32 594 cases) (40.33/100 000), of fungal keratitis (26 671 cases) (33/100 000) and of chronic pulmonary aspergillosis (5890 cases) (7.29/100 000). The estimated annual incidence for invasive aspergillosis is lower (3911 cases) (4.84/100 000 annually). Among about 22.5 million women aged 15-50 years, recurrent vulvovaginal candidiasis is estimated to occur in 1 350 371 (3342/100 000) females. The burden of three superficial fungal infections was also estimated: tinea pedis (1.79 million), tinea capitis (43 900) and onychomycosis (1.73 million). Given that the modelling estimates reported in the current study might be substantially under- or overestimated, formal epidemiological and comprehensive surveillance studies are required to validate or modify these estimates.

Direct measurement of upper airway inflammation in children with chronic rhinosinusitis: implications for asthma

PURPOSE OF REVIEW

Chronic rhinosinusitis (CRS) is a common heterogenous multifactorial disorder affecting children and adults. The exact mechanism is not completely understood. In this review, we aim to summarize our recent findings regarding etiologies and pathogenesis of CRS in children and review recent studies investigating inflammatory patterns in the upper airways in children and adults with CRS.

RECENT FINDINGS

There are only a few small studies measuring upper airway inflammation in children with CRS. These studies demonstrated more toward eosinophilic and T-cell driven inflammatory pattern. Cytokine patterns in upper airways seem to correlate with asthma symptoms in children with CRS. Adult studies demonstrate eosinophilic and Th-2 (T helper-1) driven inflammation in CRS with nasal polyps and Th-1 (T helper-2) driven inflammation in CRS without nasal polyps.

SUMMARY

Current knowledge about the characteristics of tissue inflammation in upper airways in children with CRS is limited. More studies are needed to better understand the pathogenesis and better define the subgroups of CRS. The findings of such studies will lead to identifying the biological targets to treat this condition.

Association of Mucosal Organisms with Patterns of Inflammation in Chronic Rhinosinusitis

Background

Chronic rhinosinusitis is a multifactorial process disease in which bacterial infection or colonization may play an important role in the initiation or persistence of inflammatory response. The association between mucosal bacteria presence and inflammatory patterns has only been partially explored.

Objective

To demonstrate specific mucosal microorganisms possible association with inflammatory patterns.

Methods

We collected nasal polyps or sinus tissues from a clinical selection of six patient groups with defined sinus disease using tissue biomarkers. In the tissues, we detected bacteria using peptide nucleic acid fluorescence in situ hybridization (PNA-FISH).

Results

After reviewing a total of 115 samples (15–20 samples per group), the mucosal presence of Staphylococcus aureus was correlated with IL-5 and SE-IgE positive chronic rhinosinusitis with nasal polyps and nasal polyps from cystic fibrosis patients. Chronic rhinosinusitis without nasal polyps with TNFα >20 pg/ml was associated with the mucosal presence of Pseudomonas aeruginosa.

Conclusion

This study identifies the relationship between intramucosal microbes and inflammatory patterns, suggesting that bacteria may affect the type of inflammation in chronic rhinosinusitis. Additional investigation is needed to further identify the nature of the relationship.

The inflammatory response of eosinophil-related fungal rhinosinusitis varies with inciting fungi

Earlier studies demonstrated immunological response to Alternaria alternata in patients with eosinophil-related fungal rhinosinusitis (FRS). However, Aspergillus flavus rather than A. alternata is predominantly isolated from such patients in Asia. We compared immunological response to A. flavus and A. alternata in our patients with eosinophil related FRS. Total immunoglobulin E, absolute eosinophil count (AEC), cytokine response, and in vitro eosinophil degranulation in the presence of A. flavus/A. alternata were compared among patients with eosinophil-related FRS, non-eosinophilic rhinosinusitis (NECRS), and healthy individuals. Eosinophil-related FRS patients were subgrouped into: Group A - presence of mucin with fungus in tissues and positive immediate hypersensitivity; group B - presence of mucin with fungus in biopsies and no immediate hypersensitivity; and group C - presence of mucin without fungi and hypersensitivity. A. flavus was the predominant (89%) isolate. Significantly higher major basic protein (MBP) was induced by A. flavus in Group A (279.15 ± 32.29 ng/2.5 × 10(5) cells) compared to Group B (254.9 ± 17.14 ng), Group C (238.33 ± 17.56 ng), NECRS (56.96 ± 10.97 ng), and normal subjects (28.73 ± 7.04 ng). A. alternata - eosinophil interaction failed to induce detectable MBP. AEC and serum cytokines, interleukin (IL)- 2, IL-4, IL-5, IL-10, tumor necrosis factor α, and interferon-γ were significantly higher (P < 0.001) in eosinophil-related FRS compared to NECRS and control. Thus a mixed Th1 and Th2 cytokine response was observed in eosinophil-related FRS. In conclusion, immune response in eosinophil-related FRS depends on locally inciting fungi rather than A. alternata in all instances, and the categorization of this group appears to be arbitrary.

The microbiome of chronic rhinosinusitis: culture, molecular diagnostics and biofilm detection

Background

Bacteria and fungi are believed to influence mucosal inflammation in chronic rhinosinusitis (CRS). However their presence and relationship to disease is debated. This study used multiple detection methods to compare microbial diversity and microbial abundance in healthy and diseased sinonasal mucosa. The utility of contemporary detection methods is also examined.

Methods

Sinonasal mucosa was analyzed from 38 CRS and 6 controls. Bacterial and fungal analysis was performed using conventional culture, molecular diagnostics (polymerase chain reaction coupled with electrospray ionization time-of-flight mass spectrometry) and fluorescence in situ hybridization.

Results

Microbes were detected in all samples, including controls, and were often polymicrobial. 33 different bacterial species were detected in CRS, 5 in control patients, with frequent recovery of anaerobes. Staphylococcus aureus and Propionibacterium acnes were the most common organisms in CRS and controls, respectively. Using a model organism, FISH had a sensitivity of 78%, and a specificity of 93%. Many species were detected in both CRS and controls however, microbial abundance was associated with disease manifestation.

Conclusions

This study highlights some cornerstones of microbial variations in healthy and diseased paranasal sinuses. Whilst the healthy sinus is clearly not sterile, it appears prevalence and abundance of organisms is critical in determining disease. Evidence from high-sensitivity techniques, limits the role of fungi in CRS to a small group of patients. Comparison with molecular analysis suggests that the detection threshold of FISH and culture is related to organism abundance and, furthermore, culture tends to select for rapidly growing organisms.

Role of fungi in the pathophysiology of chronic rhinosinusitis: an update

The pathogenesis of chronic rhinosinusitis (CRS) is multi-factorial with an infectious process likely at least partly involved. While bacteria have been proposed to play a critical role in CRS, fungi have also been implicated by some investigators, although the pathogenesis of fungi in CRS represents a significant controversy among rhinologists. Fungal-associated factors believed to be involved in CRS include the ability of fungi to induce significant inflammatory reactions by different means through inducing localized cytokine production in the sinonasal tract. Despite these observations, randomized, controlled studies on CRS patients using antifungal therapy have not resulted in significant improvement in CRS patients. The role of fungi in the pathogenesis of CRS remains controversial.

Simultaneous detection and identification of Aspergillus and mucorales species in tissues collected from patients with fungal rhinosinusitis

Rapid detection and differentiation of Aspergillus and Mucorales species in fungal rhinosinusitis diagnosis are desirable, since the clinical management and prognosis associated with the two taxa are fundamentally different. We describe an assay based on a combination of broad-range PCR amplification and reverse line blot hybridization (PCR/RLB) to detect and differentiate the pathogens causing fungal rhinosinusitis, which include five Aspergillus species (A. fumigatus, A. flavus, A. niger, A. terreus, and A. nidulans) and seven Mucorales species (Mucor heimalis, Mucor racemosus, Mucor cercinelloidea, Rhizopus arrhizus, Rhizopus microsporus, Rhizomucor pusillus, and Absidia corymbifera). The assay was validated with 98 well-characterized clinical isolates and 41 clinical tissue specimens. PCR/RLB showed high sensitivity and specificity, with 100% correct identifications of 98 clinical isolates and no cross-hybridization between the species-specific probes. Results for five control isolates, Candida albicans, Fusarium solani, Scedosporium apiospermum, Penicillium marneffei, and Exophiala verrucosa, were negative as judged by PCR/RLB. The analytical sensitivity of PCR/RLB was found to be 1.8 × 10(-3) ng/μl by 10-fold serial dilution of Aspergillus genomic DNA. The assay identified 35 of 41 (85.4%) clinical specimens, exhibiting a higher sensitivity than fungal culture (22 of 41; 53.7%) and direct sequencing (18 of 41; 43.9%). PCR/RLB similarly showed high specificity, with correct identification 16 of 18 specimens detected by internal transcribed spacer (ITS) sequencing and 16 of 22 detected by fungal culture, but it also has the additional advantage of being able to detect mixed infection in a single clinical specimen. The PCR/RLB assay thus provides a rapid and reliable option for laboratory diagnosis of fungal rhinosinusitis.