The human microbiome incorporates bacteria, archaea, fungi, viruses, and bacteriophages (phages).1 Phages play a remarkable role concurrently as microbiome-regulating mediators and immune factors. This discovery enhances the proposition of a correlation between the reduction of their presence and the exacerbation of symptoms in patients with allergies or asthma.2-5 This study has been conducted within the framework of a more extensive research project named CURE (Constructing a ‘Eubiosis Reinstatement Therapy’ for Asthma), which is dedicated to investigating the potency of phage therapy in patients with asthma. The present study examined intra- and interdaily fluctuations in the populations of Moraxella catarrhalis, Staphylococcus aureus, and Streptococcus pneumoniae phages that colonise the human upper respiratory system.
MATERIALS AND METHODS
This study included 18 subjects of both sexes, aged 18–54 years. Half of the participants had nasopharyngeal swab specimens collected twice daily, and the other half three times a day. Samples were collected day-by-day for a total of 3 days. In the 135 samples that were taken, DNA isolation was performed using the NucleoSpin® Plasmid (Macherey–Nagel, Düren, Germany) kit. The detection of the phage genetic material was carried out using SYBR Green-based quantitative PCR. Statistical analysis of the results was performed with SPSS version 20 (IBM, Armonk, New York, USA) and STATGRAPHICS 19 (Statgraphic Technologies, Inc., The Plains, Virginia, USA) softwares.
M. catarrhalis phage population was observed more frequently in comparison with the other two examined species. This species was detected in 80% of the subjects both in the morning and at night. The variation of the phage population was estimated by means of simple regression analysis. The expression of M. catarrhalis and S. aureus phages appeared to be associated with time. While there was no intradaily variation, a progressively increasing interdaily trend was observed in M. catarrhalis phages, while the S. aureus phage population seemed slightly reduced in the third night of the experiment.
No significant alterations were observed in the S. pneumoniae phages.
Evidence suggests that phage populations tend to differentiate in relation to time. Considering this underlying correlation, this subject has the potential of further investigation, for the elucidation of all its aspects.