The impact of Lactococcus lactis (probiotic nasal rinse) co-culture on growth of patient-derived strains of Pseudomonas aeruginosa

Advances in co-pathogenesis of the united airway diseases

According to the concept of "united airway diseases", the airway is a single organ in which upper and lower airway diseases are commonly comorbid. A range of inflammatory factors have been found to play an important role in the chain reaction of upper and lower airway diseases. However, the amount of research on this concept remains limited. The underlying mechanism of the relationship between typical diseases of the united airway, such as asthma, allergic rhinitis, and chronic sinusitis, also needs to be further explored. This review highlights the interaction between upper and lower respiratory diseases gathered from epidemiological, histoembryology, neural mechanistic, microbiological, and clinical studies, revealing the relationship between the upper and lower respiratory tracts.

Host-microbe interactions in chronic rhinosinusitis biofilms and models for investigation

Chronic rhinosinusitis (CRS) is a debilitating condition characterized by long-lasting inflammation of the paranasal sinuses. It affects a significant portion of the population, causing a considerable burden on individuals and healthcare systems. The pathogenesis of CRS is multifactorial, with bacterial infections playing a crucial role in CRS development and persistence. In recent years, the presence of biofilms has emerged as a key contributor to the chronicity of sinusitis, further complicating treatment and exacerbating symptoms. This review aims to explore the role of biofilms in CRS, focusing on the involvement of the bacterial species Staphylococcus aureus and Pseudomonas aeruginosa, their interactions in chronic infections, and model systems for studying biofilms in CRS. These species serve as an example of how microbial interplay can influence disease progression and exemplify the need for continued investigation and innovation in CRS research.

Role of probiotics in chronic rhinosinusitis: a systematic review of randomised, controlled trials

OBJECTIVE

This review evaluated the safety profile and efficacy of probiotics in chronic rhinosinusitis and was registered with Prospero (Centre for Reviews and Dissemination number: 42020193529).

METHOD

Literature databases were searched through inception to August 2022. Randomised, controlled trials exploring adjunctive probiotics in adult chronic rhinosinusitis patients were included. From 948 records screened, 4 randomised, controlled trials were included.

RESULTS

Probiotics-associated adverse effects comprised epistaxis and abdominal pain. No reduction in Sino-Nasal Outcome Test values before 4 weeks (p = 0.58) or beyond 8 weeks (p = 0.08) of treatment or reduction of severe symptom frequency (p = 0.75) was observed. Symptom relapse in probiotic-treated patients was significantly lower across all timepoints (p = 0.045). Lower sinusitis relapse risks during treatment (risk ratio = 0.49; p = 0.019) and 8 months post-treatment (risk ratio = 0.56, p = 0.013) were observed. Probiotics demonstrated potential in improving Sino-Nasal Outcome Test symptom subscales, including sleep, psychological and rhinology subscales.

CONCLUSION

The optimal mode of probiotic administration, treatment duration and target patient subgroups requires further study to evaluate the utility of probiotics.

Investigating the Antagonistic Effect of Indigenous Probiotics on Carbapenem-Resistant Pseudomonas aeruginosa Strains

Introduction

With the increase of hospital infections due to the indiscriminate use of antibiotics, multidrug resistance has increased, decreasing the effectiveness of antibiotics against these infections. For this reason, the identification of alternative agents such as probiotics has been considered. The aim of this study was to isolate and identify effective probiotics against carbapenem-resistant Pseudomonas aeruginosa strains. Material and Methods. During a period of eight months, isolates of P. aeruginosa were collected from patients in three hospitals in Isfahan. The presence of metallo-beta-lactamase enzymes was determined by the combination disc test (CDT). The inhibitory and antimicrobial activities of 20 probiotic bacteria isolated from local dairy products against these strains were investigated by agar dilution. Two probiotic strains that showed broader inhibition results were selected, and the values of the lowest inhibitory concentration (MIC) and the lowest lethal concentration (MBC) and their antibiofilm effect were determined using the microtiter plate method. The concentration of organic acids was done by HPLC. Findings. Of the 100 samples isolated and identified, 61 samples (61%) exhibited multiple drug resistance (MDR) and were selected for further investigation. Phenotypic diagnosis of the presence of metallo-beta-lactamase enzymes revealed that 74.5% of the strains were positive. The results showed that these two probiotics killed P. aeruginosa strains after only one hour, and the inhibition mechanism was due to the presence of lactic acid and acetic acid. The antibiofilm effect of these two probiotics was at concentrations of 1/2 and 1/4.

Conclusion

The two Lactobacillus isolates had potential antimicrobial and antibiofilm properties against all carbapenem-resistant P. aeruginosa strains, even at thinner dilutions. Considering the broad activity of this strain, it can potentially be used for biocontrol of these strains.

Intermittent fasting supports the balance of the gut microbiota composition

There is a growing body of detailed research demonstrating that intermittent fasting is essentially a cleansing activity in terms of health. Especially since its applications that exceed 16 h trigger autophagy, it continues its effect on all tissue and organ systems after the regeneration movement that starts at the cellular level. Similarly, it continues to be better understood with each passing day that the gut microbiota (GM) has many positive effects on all tissue and organ systems. Although the GM is affected by many different parameters, dietary habits are reported to be the most effective factor. Therefore, it is important to investigate the effects of different preferred fasting practices on the GM, which has numerous health benefits. Pointing out this situation, this study aims to determine the effects of 18-h intermittent fasting for 5 weeks on the shaping of GM. A 12-month-old male Wistar rat was chosen as the model organism in the study. At the end of the application, the metagenome was applied to the cecum content of the intestinal tissue collected from the sacrificed animals. Intermittent fasting practice led to an increase in alpha diversity, which expresses a significant bacterial diversity, the stabilization of Firmicutes and Bacteroidetes ratios (F/B), and the reshaping of the values with the highest prevalence in all stages of the classification, especially in the family, genus, and species care. Analysis results showed that the preferred intermittent fasting program helps balance the GM composition. This study is an important example showing the strong positive link between intermittent fasting and GM.

Recent Advances in Fungal Infections: From Lung Ecology to Therapeutic Strategies With a Focus on Aspergillus spp

Fungal infections are estimated to be the main cause of death for more than 1.5 million people worldwide annually. However, fungal pathogenicity has been largely neglected. This is notably the case for pulmonary fungal infections, which are difficult to diagnose and to treat. We are currently facing a global emergence of antifungal resistance, which decreases the chances of survival for affected patients. New therapeutic approaches are therefore needed to face these life-threatening fungal infections. In this review, we will provide a general overview on respiratory fungal infections, with a focus on fungi of the genus Aspergillus. Next, the immunological and microbiological mechanisms of fungal pathogenesis will be discussed. The role of the respiratory mycobiota and its interactions with the bacterial microbiota on lung fungal infections will be presented from an ecological perspective. Finally, we will focus on existing and future innovative approaches for the treatment of respiratory fungal infections.

Unravelling the role of the microbiome in chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a complex, heterogenous condition with likely infectious and inflammatory causative factors. Renewed interest in the role that microbes play in this condition has stemmed from advancements in microbe identification and parallel research that has implicated the role of the microbiome in other chronic inflammatory conditions. This clinical commentary provides a review of the current literature relevant to chronic rhinosinusitis. Particular focus is paid to factors specific to the investigation of the sinonasal microbiome, evidence for the role of dysbiosis in the disease state and influences that may impact the microbiome. Possible mechanisms of disease and therapeutic implications through microbial manipulation are also reviewed, as are deficiencies and limitations of the current body of research.

The Role of Probiotics in Chronic Rhinosinusitis Treatment: An Update of the Current Literature

Chronic rhinosinusitis (CRS) is a significant health problem. It affects 5–12% of the general population. The causes that underlie the onset of CRS are not yet well known. However, many factors may contribute to its onset, such as environmental factors and the host’s general condition. Medical treatment mainly uses local corticosteroids, nasal irrigation, and antibiotics. In recent years, a new therapeutic approach that employs the use of probiotics emerged. Probiotics have been extensively studied as a therapy for dysbiosis and inflammatory pathologies of various parts of the body. We aimed to examine the studies in vivo and in vitro and clinicals reports in the existing literature to update probiotics’ role in rhinosinusitis chronic medical treatment.

International consensus statement on allergy and rhinology: rhinosinusitis 2021

I.

EXECUTIVE SUMMARY

BACKGROUND: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR-RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR-RS-2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence-based findings of the document.

METHODS

ICAR-RS presents over 180 topics in the forms of evidence-based reviews with recommendations (EBRRs), evidence-based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary.

RESULTS

ICAR-RS-2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence-based management algorithm is provided.

CONCLUSION

This ICAR-RS-2021 executive summary provides a compilation of the evidence-based recommendations for medical and surgical treatment of the most common forms of RS.

Microbiomics of irrigation with xylitol or Lactococcus lactis in chronic rhinosinusitis

OBJECTIVE

Topical sinonasal rinse therapies may alter the local microbiome and improve disease control in chronic rhinosinusitis (CRS). The objective of this study was to examine microbiome changes in post-surgical CRS patients when rinsing with commercially available products containing xylitol or Lactococcus lactis.

METHODS

A crossover-type protocol with a washout period was designed. Swab samples from anterior ethmoid cavities of CRS patients were collected prospectively at baseline. Subjects were provided packets containing either L. lactis W136 or xylitol in non-blinded fashion and instructed to add it to their rinse bottles daily for 28 days, after which another swab was taken. A saline wash-out period was completed and a third swab taken. A final 28-day regimen of the opposite product was followed by a final swab. DNA extraction and sequencing of the 16S rRNA gene allowed for global microbiome analysis.

RESULTS

We enrolled 25 subjects with CRS and 10 controls resulting in 70 adequate samples. Increased detection of Lactococcus was observed after use of L. lactis. No significant trends in alpha or beta diversity as a result of treatment were observed. SNOT-22 score did not change significantly following treatment with xylitol, L. lactis, or saline.

CONCLUSION

We did not detect any major clinical or microbiome-level effect due to treatment with two topical rinse products. Further research is needed to elucidate their clinical utility and possible probiotic effect.

LEVEL OF EVIDENCE

3.

Contribution of Short Chain Fatty Acids to the Growth of Pseudomonas aeruginosa in Rhinosinusitis

Background: Chronic rhinosinusitis (CRS) is characterized by complex bacterial infections with persistent inflammation. Based on our rabbit model of sinusitis, blockage of sinus ostia generated a shift in microbiota to a predominance of mucin degrading microbes (MDM) with acute inflammation at 2 weeks. This was followed by conversion to chronic sinus inflammation at 3 months with a robust increase in pathogenic bacteria (e.g., Pseudomonas). MDMs are known to produce acid metabolites [short chain fatty acids (SCFA)] that have the potential to stimulate pathogen growth by offering a carbon source to non-fermenting sinus pathogens (e.g., Pseudomonas). The objective of this study is to evaluate the concentrations of SCFA within the mucus and its contribution to the growth of P. aeruginosa. Methods: Healthy and sinusitis mucus from the rabbit model were collected and co-cultured with the PAO1 strain of P. aeruginosa for 72 h and colony forming units (CFUs) were determined with the targeted quantification of three SCFAs (acetate, propionate, butyrate). Quantification of SCFAs in healthy and sinusitis mucus from patients with P. aeruginosa was also performed via high performance liquid chromatography. Results: To provide evidence of fermentative activity, SCFAs were quantified within the mucus samples from rabbits with and without sinusitis. Acetate concentrations were significantly greater in sinusitis mucus compared to controls (4.13 ± 0.53 vs. 1.94 ± 0.44 mM, p < 0.01). After 72 h of co-culturing mucus samples with PAO1 in the presence of mucin medium, the blue-green pigment characteristic of Pseudomonas was observed throughout tubes containing sinusitis mucus. CFUs were higher in cultures containing mucus samples from sinusitis (8.4 × 10⁹ ± 4.8 × 10⁷) compared to control (1.4 × 10⁹ ± 2.0 × 10⁷) or no mucus (1.5 × 10⁹ ± 2.1 × 10⁷) (p < 0.0001). To provide evidence of fermentative activity in human CRS with P. aeruginosa, the presence of SCFAs in human mucus was analyzed and all SCFAs were significantly higher in CRS with P. aeruginosa compared to controls (p < 0.05). Conclusion: Given that SCFAs are solely derived from bacterial fermentation, our evidence suggests a critical role for mucin-degrading bacteria in generating carbon-source nutrients for pathogens. MDM may contribute to the development of recalcitrant CRS by degrading mucins, thus providing nutrients for potential pathogens like P. aeruginosa.

The Microbiome in Cystic Fibrosis Pulmonary Disease

Cystic fibrosis (CF) is a genetic disease with mutational changes leading to profound dysbiosis, both pulmonary and intestinal, from a very young age. This dysbiosis plays an important role in clinical manifestations, particularly in the lungs, affected by chronic infection. The range of microbiological tools has recently been enriched by metagenomics based on next-generation sequencing (NGS). Currently applied essentially in a gene-targeted manner, metagenomics has enabled very exhaustive description of bacterial communities in the CF lung niche and, to a lesser extent, the fungi. Aided by progress in bioinformatics, this now makes it possible to envisage shotgun sequencing and opens the door to other areas of the microbial world, the virome, and the archaeome, for which almost everything remains to be described in cystic fibrosis. Paradoxically, applying NGS in microbiology has seen a rebirth of bacterial culture, but in an extended manner (culturomics), which has proved to be a perfectly complementary approach to NGS. Animal models have also proved indispensable for validating microbiome pathophysiological hypotheses. Description of pathological microbiomes and correlation with clinical status and therapeutics (antibiotic therapy, cystic fibrosis transmembrane conductance regulator (CFTR) modulators) revealed the richness of microbiome data, enabling description of predictive and follow-up biomarkers. Although monogenic, CF is a multifactorial disease, and both genotype and microbiome profiles are crucial interconnected factors in disease progression. Microbiome-genome interactions are thus important to decipher.