Analysis of Phage Regulatory RNAs: Sequencing Library Construction from the Fraction of Small Prokaryotic RNAs Less Than 50 Nucleotides in Length.

So far, bacterial regulatory sRNAs of length less than 50 nucleotides have been poorly understood, and a low number of such molecules has been identified. The first microRNA-size functional ribonucleic acid occurring in a bacterial cell has been described only recently, and it was found to be encoded by a bacteriophage. One of the reasons for such a scarcity in this field is the lack of procedures intended for the isolation and selection of molecules of this size from bacterial cells. To meet these difficulties, we describe here the few-step procedure of isolation, purification, selection, and sequencing library preparation that is dedicated to the fraction of very small, bacterial RNA molecules.

Bacteriophage-encoded 24B_1 molecule resembles herpesviral microRNAs and plays a crucial role in the development of both the virus and its host.

The 24B_1 small non-coding RNA molecule has been identified in Escherichia coli after induction of Shiga toxin-converting bacteriophage Φ24B. In this work, we focused on its direct role during phage and bacterial host development. We observed that in many aspects, this phage sRNA resembles herpesviral microRNAs. Similar to microRNAs, the mature 24B_1 is a short molecule, consisting of just 20 nucleotides. It is generated by cleaving the 80-nt long precursor transcript, and likely it undergoes a multi-step maturation process in which the Hfq protein plays an important role, as confirmed by demonstration of its binding to the 24B_1 precursor, but not to the 24B_1 mature form. Moreover, 24B_1 plays a significant role in maintaining the prophage state and reprogramming the host's energy metabolism. We proved that overproduction of this molecule causes the opposite physiological effects to the mutant devoid of the 24B_1 gene, and thus, favors the lysogenic pathway. Furthermore, the 24B_1 overrepresentation significantly increases the efficiency of expression of phage genes coding for proteins CI, CII, and CIII which are engaged in the maintenance of the prophage. It seems that through binding to mRNA of the sdhB gene, coding for the succinate dehydrogenase subunit, the 24B_1 alters the central carbon metabolism and causes a drop in the ATP intracellular level. Interestingly, a similar effect, called the Warburg switch, is caused by herpesviral microRNAs and it is observed in cancer cells. The advantage of the Warburg effect is still unclear, however, it was proposed that the metabolism of cancer cells, and all rapidly dividing cells, is adopted to convert nutrients such as glucose and glutamine faster and more efficiently into biomass. The availability of essential building blocks, such as nucleotides, amino acids, and lipids, is crucial for effective cell proliferation which in turn is essential for the prophage and its host to stay in the lysogenic state.

[Waterpipe smoking among adolescents in Silesia region of Poland]. / Fajka wodna jako alternatywny sposób palenia tytoniu przez mlodziez na terenie województwa slaskiego.

SIGNIFICANCE: Waterpipe has been used for many centuries in Asia and Africa regions to smoke tobacco leaves. In recent years it has been gaining popularity also among adolescents and youths in Poland. AIM OF THE STUDY: The aim of the study was to examine waterpipe smoking prevalence among adolescents living in Silesia region of Poland. We investigated if waterpipe is used as alternative way to smoke tobacco and awareness among adolescents about heath risk of waterpipe smoking. METHODS: We surveyed 769 students of high schools located in Silesia region of Poland. RESULTS: Mean age of surveyed students was 16.5 years, and 52.5% were females. Our results showed that prevalence of waterpipe was higher than cigarette smoking (46.7% vs. 34.6%). Prevalence of waterpipe smoking among girls was almost the same as among boys. Most of the surveyed students used waterpipe as an alternative tool to smoke tobacco. CONCLUSIONS: The prevalence of waterpipe smoking among Polish adolescents is very high. There is an urgent need for education about health risks of waterpipe use in Poland.