Recent Trends in Bacteriology of Adult Patients with Chronic Rhinosinusitis

Insights from bioinformatics analysis reveal that lipopolysaccharide induces activation of chemokine-related signaling pathways in human nasal epithelial cells

Lipopolysaccharide (LPS) is known to elicit a robust immune response. This study aimed to investigate the impact of LPS on the transcriptome of human nasal epithelial cells (HNEpC). HNEpC were cultured and stimulated with LPS (1 μg/mL) or an equivalent amount of normal culture medium. Subsequently, total RNA was extracted, purified, and sequenced using next-generation RNA sequencing technology. Differentially expressed genes (DEGs) were identified and subjected to functional enrichment analysis. A protein-protein interaction (PPI) network of DEGs was constructed, followed by Ingenuity Pathway Analysis (IPA) to identify molecular pathways influenced by LPS exposure on HNEpC. Validation of key genes was performed using quantitative real-time PCR (qRT-PCR). A total of 97 DEGs, comprising 48 up-regulated genes and 49 down-regulated genes, were identified. Results from functional enrichment analysis, PPI, and IPA indicated that DEGs were predominantly enriched in chemokine-related signaling pathways. Subsequent qRT-PCR validation demonstrated significant upregulation of key genes in these pathways in LPS-treated HNEpC compared to control cells. In conclusion, LPS intervention profoundly altered the transcriptome of HNEpC, potentially exacerbating inflammatory responses through the activation of chemokine-related signaling pathways.

Bacteriology of Different Phenotypes of Chronic Rhinosinusitis

OBJECTIVES

Chronic rhinosinusitis (CRS) reduces the health-related quality of life and subsequently causes a tremendous socio-economic impact. Although many studies have been conducted, few have identified a relationship between bacteriological characteristics and different phenotypes or endotypes. Therefore, this study aimed to elucidate the recent trends in bacterial cultures from different types of CRS in the Asian population.

METHODS

This retrospective case-control study recruited patients diagnosed with CRS who underwent functional endoscopic sinus surgery (FESS) at a tertiary hospital in Taiwan. The patients were classified into those with chronic rhinosinusitis with nasal polyps (CRSwNP)/chronic rhinosinusitis without nasal polyps (CRSsNP), eosinophilic chronic rhinosinusitis (eCRS)/non-eosinophilic chronic rhinosinusitis (NECRS), and central compartment atopic disease (CCAD)/lateral-dominant nasal polyp (LDNP) groups. The demographic data and bacteriological characteristics of the groups were analyzed.

RESULTS

We included 503 patients, identifying no significant difference between CRSwNP and CRSsNP for several common bacteria in CRS. The number of Staphylococcus epidermidis isolates in culture was significantly higher in the NECRS group (50.46% vs. 32.56%, p = 0.0003) than that in the eCRS group. The number of methicillin-resistant Staphylococcus aureus (MRSA; 8.51% vs. 2.35%, p = 0.0221) positive isolates was significantly higher in the CCAD group than that in the LDNP group.

CONCLUSIONS

This was the first study in Asia to analyze the relationship between bacteriological characteristics and CCAD. MRSA is significantly higher in the CCAD group than that in the LDNP group. Recognizing the unique microbiology of CRSwNP, eCRS, and CCAD is crucial when selecting antimicrobial therapy to lessen the socio-economic impact.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:1071-1076, 2024.

Comparison of Bacteriology Between Eosinophilic and Noneosinophilic Chronic Rhinosinusitis With Nasal Polyps

OBJECTIVE

To compare culture results between eosinophilic chronic rhinosinusitis (CRS) with nasal polyps (ECRSwNP) and noneosinophilic CRS with nasal polyps (nECRSwNP).

STUDY DESIGN

Retrospective study.

SETTING

Tertiary medical center.

METHODS

We retrospectively analyzed a cohort of CRSwNP patients undergoing primary functional endoscopic sinus surgery. Prior to surgery, swab samples for bacterial culture were collected from their middle meatus using cotton tips. After surgery, postoperative specimens were histologically examined for tissue eosinophilia. A tissue eosinophil density of >10 cells at high power magnification was used to discriminate between ECRSwNP and nECRSwNP.

RESULTS

A total of 295 patients were studied with polyps present on 471 sides of the nasal cavity. Among them, 236 sides were ECRSwNP, and the remaining 235 sides were nECRSwNP. Bacterial growth was found in 94 ECRSwNP sides, and in 88 nECRSwNP sides. Culture rates were similar between ECRSwNP and nECRSwNP sides (p = .595). However, Gram-negative aerobes were found in 25 of 236 ECRSwNP sides, and in 42 of 235 nECRSwNP sides. The Gram-negative culture rate was significantly higher in nECRSwNP than in ECRSwNP sides (p = .024).

CONCLUSION

The bacteriology of CRS was different between ECRSwNP and nECRSwNP. The Gram-negative aerobes were present more in nECRSwNP than in ECRSwNP.

Effect of microplastics on nasal and intestinal microbiota of the high-exposure population

Background

Microplastic has become a growing environmental problem. A balanced microbial environment is an important factor in human health. This study is the first observational cross-sectional study focusing on the effects of microplastics on the nasal and gut microbiota in a highly exposed population.

Methods

We recruited 20 subjects from a Plastic Factory (microplastics high-exposure area) and the other 20 from Huanhuaxi Park (microplastics low-exposure area) in Chengdu, China. We performed the microplastic analysis of soil, air, and intestinal secretions by laser infrared imaging, and microbiological analysis of nasal and intestinal secretions by 16S rDNA sequencing.

Results

The result shows that the detected points of microplastics in the environment of the high-exposure area were significantly more than in the low-exposure area. Polyurethane was the main microplastic component detected. The microplastic content of intestinal secretions in the high-exposure group was significantly higher than in the low-exposure group. Specifically, the contents of polyurethane, silicone resin, ethylene-vinyl acetate copolymer, and polyethylene in the high-exposure group were significantly higher than in the low-exposure group. Moreover, high exposure may increase the abundance of nasal microbiotas, which are positively associated with respiratory tract diseases, such as Klebsiella and Helicobacter, and reduce the abundance of those beneficial ones, such as Bacteroides. Simultaneously, it may increase the abundance of intestinal microbiotas, which are positively associated with digestive tract diseases, such as Bifidobacterium, Streptococcus, and Sphingomonas, and reduce the abundance of intestinal microbiotas, which are beneficial for health, such as Ruminococcus Torquesgroup, Dorea, Fusobacterium, and Coprococcus. A combined analysis revealed that high exposure to microplastics may not only lead to alterations in dominant intestinal and nasal microbiotas but also change the symbiotic relationship between intestinal and nasal microbiotas.

Conclusion

The results innovatively revealed how microplastics can affect the intestinal and nasal microecosystems.

Clinical trial registration

ChiCTR2100049480 on August 2, 2021.

The difference in pathogenic bacteria between chronic rhinosinusitis in patients with and without Sjogren's syndrome: a retrospective case-control study

Background

Chronic rhinosinusitis (CRS) affects the quality of life of many people worldwide and can cause comorbidities. Our previous research proved that Sjogren’s syndrome (SS) is a predisposing factor for CRS, with a 2.5-fold associated risk. Antibiotics are important in CRS treatment; however, there is a paucity of research on the pathogenic bacteria of SS-CRS in the past. We conducted this study to investigate the pathogenic difference of SS-CRS and non-SS-CRS and aimed to give clinicians references when selecting antibiotics to treat SS-CRS.

Materials and methods

A total of 14,678 patients hospitalized for CRS operation from 2004 to 2018 were identified from the Chang Gung Research Database. These CRS cases were classified as either SS-CRS or non-SS-CRS. We analyzed their bacterial distribution by studying the results of the pus cultures performed alongside surgery.

Results

The top three facultative anaerobic or aerobic isolated bacteria in the SS-CRS group were coagulase-negative Staphylococcus (CoNS: 34.3%), Pseudomonas aeruginosa (28.6%), methicillin-sensitive Staphylococcus aureus (MSSA: 20%), and Staphylococcus epidermidis (20%). In the non-SS-CRS group, S. epidermidis (29.3%), CoNS (25.7%), and MSSA (14.2%) were identified. The top three anaerobic bacterial genera were Cutibacterium (54.3%), Peptostreptococcus (11.4%), and Fusobacterium (11.4%) in the SS-CRS group and Cutibacterium (53.8%), Peptostreptococcus (25%), and Prevotella (12.9%) in the non-SS-CRS group.

Conclusions

P.aeruginosa is a major pathogen in SS-CRS patients. In addition, physicians should be aware of potential Fusobacterium and antibiotic-resistant bacterial infection in patients with SS-CRS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07652-4.

Benzyl Isothiocyanate Attenuates Inflammasome Activation in Pseudomonas aeruginosa LPS-Stimulated THP-1 Cells and Exerts Regulation through the MAPKs/NF-κB Pathway

Inflammasomes are a group of intracellular multiprotein platforms that play important roles in immune systems. Benzyl isothiocyanate (BITC) is a constituent of cruciferous plants and has been confirmed to exhibit various biological activities. The modulatory effects of BITC on inflammasome-mediated interleukin (IL)-1β expression and its regulatory mechanisms in Pseudomonas aeruginosa (P. aeruginosa) LPS/ATP-stimulated THP-1 cells was investigated. Monocytic THP-1 cells were treated with phorbol myristate acetate (PMA) to induce differentiation into macrophages. Enzyme-linked immunosorbent assays (ELISA) were performed to measure the levels of IL-1β produced in P. aeruginosa LPS/ATP-exposed THP-1 cells. Western blotting was performed to examine the BITC modulatory mechanisms in inflammasome-mediated signaling pathways. BITC inhibited IL-1β production in P. aeruginosa LPS/ATP-induced THP-1 cells. BITC also inhibited activation of leucine-rich repeat protein-3 (NLRP3) and caspase-1 in P. aeruginosa LPS/ATP-induced THP-1 cells. Furthermore, we show that mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) activation in P. aeruginosa LPS was attenuated by BITC. These BITC-mediated modulatory effects on IL-1β production may have therapeutic potential for inflammasome-mediated disorders such as a nasal polyp.

Murine Model of Sinusitis Infection for Screening Antimicrobial and Immunomodulatory Therapies

The very common condition of sinusitis is characterized by persistent inflammation of the nasal cavity, which contributes to chronic rhinosinusitis and morbidity of cystic fibrosis patients. Colonization by opportunistic pathogens such as Staphylococcus aureus and Pseudomonas aeruginosa triggers inflammation that is exacerbated by defects in the innate immune response. Pathophysiological mechanisms underlying initial colonization of the sinuses are not well established. Despite their extensive use, current murine models of acute bacterial rhinosinusitis have not improved the understanding of early disease stages due to analytical limitations. In this study, a model is described that is technically simple, allows non-invasive tracking of bacterial infection, and screening of host-responses to infection and therapies. The model was modified to investigate longer-term infection and disease progression by using a less virulent, epidemic P. aeruginosa cystic fibrosis clinical isolate LESB65. Tracking of luminescent bacteria was possible after intranasal infections, which were sustained for up to 120 h post-infection, without compromising the overall welfare of the host. Production of reactive oxidative species was associated with neutrophil localization to the site of infection in this model. Further, host-defense peptides administered by Respimat® inhaler or intranasal instillation reduced bacterial burden and impacted disease progression as well as cytokine responses associated with rhinosinusitis. Thus, future studies using this model will improve our understanding of rhinosinusitis etiology and early stage pathogenesis, and can be used to screen for the efficacy of emerging therapies pre-clinically.