Respiratory viruses in the healthy middle ear and middle ear with otitis media with effusion.

To investigate the presence of respiratory viruses in the middle ear cavity of the individuals with a healthy middle ear and the children with otitis media with effusion (OME). A total of 72 middle ear samples were collected from 25 children with OME (Group 1) and 47 individuals with no middle ear disease (Group 2). Multiplex real-time polymerase chain reaction was used to investigate the presence of 20 different respiratory viruses. Virus results were compared with bacteriomes of the same populations. At least one respiratory virus was detected in 56% of the patients in Group 1 and 12.8% of the individuals in Group 2. The viral co-infection rate for Group 1 and 2 was 8% and 2.1%, respectively. In Group 1, adenovirus was the most frequently detected virus with a rate of 24%, either alone (16%) or concurrent with other viruses (8%), followed by influenza B (12%), rhinovirus, and bocavirus (8%) each. Parainfluenza 4, coronavirus OC43, and RSV A/B were detected in 4% of the sample each. In Group 2, rhinovirus was detected in two samples (4.3%) followed by adenovirus, coronavirus OC43, coronavirus E299, and coronavirus NL63 with a rate of 2.1% each. The detection rate of respiratory viruses was significantly higher in children aged 6 to 11 years. There was no positive association between virus and bacteria found in the middle ear cavity. The current study has provided comprehensive data indicating the presence of diverse respiratory viruses in the healthy middle ear cavity. Our results also suggest that respiratory viruses might have a contribution to OME pathogenesis.

Mycobiome in the Middle Ear Cavity with and Without Otitis Media with Effusion.

Objective: No data have yet been published revealing the composition and the diversity of fungal communities (mycobiome) in the human middle ear cavity. The presented study investigated the mycobiome in the middle ear cavities of individuals with healthy middle ears and patients with otitis media with effusion. Methods: A total of 77 middle ear and four adenoid samples were collected from 47 individuals (35 children and 12 adults) in Group 1 and from 20 children in Group 2. The mycobiome profile was analyzed with nuclear ribosomal internal transcribed spacer 2 (ITS2) based metabarcoding using an Illumina MiSeq metagenomics kit. Results: ITS2-based metabarcoding detected 14 different genera and 17 different species with a mean relative abundance of ≥1% in the samples analyzed. Mycobiome profile was similar between the adenoid tissue and the middle ear cavity, between Groups 1 and Group 2, and between children and adults. Fusarium, Stemphylium, Candida, and Cladosporium were the most abundant genera detected in all samples. The mean relative abundances of the genera Candida and Fusarium were remarkably higher in Group 2 compared to Group 1. Conclusion: The species Candida glaebosa, Candida cretensis, Aspergillus ruber, Penicillium desertorum, and Rhizopus arrhizus were significantly more abundant in patients with otitis media with effusion (OME), raising the possibility that they affect the pathogenesis of OME.

Mutations Observed in the SARS-CoV-2 Spike Glycoprotein and Their Effects in the Interaction of Virus with ACE-2 Receptor.

Coronaviruses (CoVs) classified in the Coronaviridae family infect a very large spectrum of vertebrate group. Seven CoVs that cause human disease consist of Alpha-CoVs, which are HCoV-229E, and NL63 and beta-CoVs, which are MERS-CoV, SARS-CoV, HCoV-OC43, HCoV-HKU1, and SARS-CoV-2. SARS-CoV-2 is an enveloped, positive-polarity, single-stranded RNA virus responsible for a new Coronavirus disease 2019 (COVID-19). The mutagenic ability of the SARS-CoV-2 directs its evolution and genome variability, thus allowing viruses to escape from host immunity and develop drug resistance. Tracing viral mutations is also important for the development of new vaccines, antiviral drugs, and diagnostic systems. During replication in the host cell, genomic mutations occur in the virus and these mutations are transferred to new generations. For this reason, systematic monitoring of mutations in the SARS-CoV-2 genome allows observation of the national and international molecular epidemiology of the virus. SARS-CoV-2 spike (S) glycoprotein is vital in the binding of the virus to the host cell receptor that is angiotensin converting-enzyme 2 (ACE2), membrane fusion, vaccine studies and immune response to the virus. Therefore, mutations in the gene encoding the S glycoprotein and especially the possible variations in the receptor binding domain (RBD) in S gene are important issues to be emphasized. In this article, information about the mutations observed in the SARS-CoV-2 S glycoprotein and their possible effects are presented.

The in vitro effect of antimicrobial photodynamic therapy on Candida and Staphylococcus biofilms

Background/aim: This study was designed to evaluate the effect of antimicrobial photodynamic treatment (APDT) in a biofilm model using combinations of various dyes (rose bengal, riboflavin, and methylene blue) as photosensitizers and light sources (LED and UVA) against staphylococcal and candidal biofilms. Materials and methods: Sterile microtiter plates were used for the development and quantification of the biofilms. APDT was carried out using combinations of the light sources and dyes. The percentage of the growth inhibition was then calculated using a spectrophotometer. The broth media in the wells were aspirated, wells were stained with crystal violet, and optical density values were measured spectrophotometrically. SEM analysis of the impact of APDT on bacterial and fungal biofilms was also performed. Results: The experiments showed that the most efficacious combination was red LED + methylene blue against both staphylococcal and candidal biofilms. A marked inhibition (45.4%) was detected on both C. albicans and C. parapsilosis biofilms. Red LED + methylene blue was also effective on S. aureus and S. epidermidis biofilms. SEM images suggested that the number of adherent cells and biofilm mass were markedly reduced after APDT treatment. Conclusion: Although the results of this study indicated the in vitro efficacy of APDT, it might also be a promising technique for the control of biofilm growth within intravenous catheters.

Role of hygienic factors in the etiology of allergic disorders in children.

BACKGROUND/AIM: We investigated the role of body flora and chronic inflammatory infections in the etiology of allergic disorders in Turkish children. MATERIALS AND METHODS: Forty pediatric asthma patients with positive skin prick tests and 40 age-matched healthy subjects with negative skin prick tests were enrolled in this cross-sectional study. Serum H. pylori IgG, viral hepatitis serology, IL-10, and TGF-beta levels were measured. Stool and throat cultures were taken and tested for occurrence of microorganisms. RESULTS: A significantly higher percentage of nonatopic subjects tested positive for anti-H. pylori antibodies compared to atopic subjects (60% vs. 20%). Serum IL-10 levels were also significantly higher in nonatopic subjects. No significant differences in direct microscopy and culture specimens of stools were observed. Examination of throat flora showed significantly higher occurrences of Neisseria and beta-hemolytic Streptococcus in nonatopic subjects, but higher occurrences of gram-positive bacilli in atopic subjects. CONCLUSION: Higher prevalence of anti-H. pylori antibody and higher serum levels of IL-10 in nonatopic subjects suggest that chronic infection and inflammation may protect against atopic disease. Higher occurrences of Neisseria and beta-hemolytic Streptococcus in throat cultures from nonatopic subjects are novel findings that lend further support to the hygiene hypothesis.