In the paper abstract, the issues of UVA and visible light photoinactivation of bacteriophage PhiX174 in media with riboflavin and the impact of the composition of a medium on the dynamics of the reduction of a virus are raised. The influence of riboflavin acting as a photosensitizer on the effectiveness of UVA and visible light irradiation of the PhiX174 virus is studied in this case. Key findings indicate that the medium requires quite different doses for the photoinactivation of the microorganisms, which points to the very significant role of the medium, particularly riboflavin, in determining the photoinactivation efficiency. This underlines the potential to utilize different compositions of media to potentiate the inactivation of viruses through photoinactivation and discloses how disinfection protocols could be optimized in diverse setups.
Contextualization of the Study
The issue of viruses on a global level came under consideration because of the 2019 coronavirus pandemic. The focus is on an increasing need for proper disinfection in everyday life and healthcare, thereby underlining the concern for safe and effective strategies. Alternatives also being applied in joint practice include thermal and ultraviolet (UV) disinfection, though chemical disinfection of ethanol is considered acceptable. Even though UV disinfection has proven to be an effectual activity against viruses, its potential for harm to man is not without consideration (Anderson & Boehm, 2023). An innovative alternative, disinfection with visible light, already used in the case of photodynamic therapy and for the inactivation of microorganisms such as bacteria and fungi, is researched. In this way, an absorbed light is generated by flavins and porphyrins from external or endogenous photosensitizers, creating the reactive oxygen species that damage cellular components, thus inactivating the cells. The present study is on photoinactivation of bacteriophage PhiX174 using UVA and visible light in media with and without the photosensitizer riboflavin. Previous studies suggest that even enveloped viruses, such as coronaviruses or influenza viruses, can be inactivated by blue or violet light irradiation. This study tackles the subject of the impact of the media composition on viral photoinactivation and thus implies the ability for safer, greener disinfection treatments.
Materials and Methods
The experimental approach, as stated in the “Materials and Methods,” discusses a complete framework in which the photoinactivation of bacteriophage PhiX174 by UVA and visible light in two different media, i.e., SM buffer and DMEM-F12, is systematically explored. Bacteriophage PhiX174 and its host E. coli were purchased from the German Collection of Microorganisms and Cell Cultures, and this facilitated the study using standardized biological materials (Gomes & Bartolomeu, 2022). Growing these microorganisms included E. The optimal optical densities were reached concerning the set titers of enriching concentration colony-forming units of E. coli and PhiX174 bacteriophages in SM buffer. When designing a controlled experiment, time is an additive component that is put into careful preparation that adds to the precision of the research.
Thus, measurements of the UVA, violet, and blue light radiations from the high-power LEDs of the irradiation experiment were consistent and controlled in irradiances. Phage samples, in pre-determined concentration, were radiated in quartz and glass beakers with minimal oscillations in temperature in a water bath (Gomes & Bartolomeu, 2022). This article is so detailed in terms of the level of the experimental setup focus, subsequent dilutions, and incubations in establishing the reduction of the virus in question. Another excellent example of rigor in the measurement of photoinactivation is applied in the double agar layering technique for plaque assay, which provides a sturdy frame for evaluating the action of light irradiation in different media on bacteriophage PhiX174.
Results
The study results, therefore, presented a differentiated understanding of the photoinactivation efficiency of bacteriophage PhiX174 when exposed to multi-wavelengths of light, most importantly UVA (366 nm), violet (408 nm), and blue (455 nm), over two different media, that is SM buffer and DMEM-F12. About UVA irradiation, there was a significant difference in doses of bacteriophage required to produce a one-log reduction in concentration for the DMEM-F12 required dose (58.2 J/cm²) from that for SM buffer (42.5 J/cm²). This trend was in place during the comparison between violet and blue light, demonstrating a medium-dependent difference in photoinactivation efficiency, with DMEM-F12 consistently showing an exaggerated response to photoinactivation.
This differential response was further highlighted when analyzing D90 doses—the dose required to obtain 90% reductions in viral concentration—across the different wavelengths and media. In contrast, on 455 nm, the blue light spectrum example, a drastic difference was noted for the D90 doses needed within DMEM-F12 compared to SM buffer, in which DMEM-F12 showed a significantly low dose requirement (3217 J/cm2) compared to SM buffer high dose (4998 J/cm2). These results not only point out the effect of medium composition on the bacteriophages’ inactivation rates by light but also signal a plausible influence of photosensitizers, such as riboflavin in DMEM-F12, on the photoreaction, which may enhance the efficacy of the inactivation under given light conditions. As such, this differential efficacy demonstrates the complexity of photoinactivation processes and suggests that strategies must be tailored according to the medium composition.
Discussion
The research discussion section brings out riboflavin’s role in the efficient photoinactivation of bacteriophage phi X174 by the medium composition, in this case, DMEM-F12 medium. It showed that the differential photoinactivation rates observed through UVA and visible light wavelengths are significantly affected by both the medium’s optical properties and the medium’s content. Riboflavin, as a photosensitizer in DMEM-F12, is a significant factor in enhancing the process of photoinactivation, having deep effects on the outcome of the photoinactivation study. This result exemplifies the need to consider the medium components in photoinactivation studies, as external photosensitizers, such as riboflavin, could distort the assessment of the intrinsic photosensitivity of viruses.
Those findings have broader implications in the virology context and photoinactivation research. This would lead to a requirement to distinguish the intrinsic photosensitivity of viruses from those effects introduced by exogenous factor photosensitizers in the medium. This study thus argues for a more nuanced perspective in assessing the protocols of virus photoinactivation, in which the irradiation and composition of the medium were optimized towards the susceptibility of the virus to the method of inactivation by light. It provides valuable insight into the intricate interplay of light, photosensitizers, and viruses, which bodes well for the new development of more potent and environmentally friendly disinfection strategies.
Limitations
The limitations in the study of the photoinactivation of bacteriophage PhiX174 by UVA and visible light in SM buffer and DMEM-F12 were based on focusing on one bacteriophage, not considering other viruses. The main limitation of this single focus is that the findings are only universally relevant for some viruses, limiting generalizability. This, the study states, is a limitation, alluding to the fact that even though PhiX174 had shown medium-dependent photoinactivation, the same might be extended to other viruses (Sommerfeld et al., 2024). The other view of the study is that when it is assumed that photoinactivation is medium-independent for some viruses, then the studies and the conclusions must be executed empirically. By itself, the recognition suggests that more research is needed for the experimental evidence proving the medium dependency of photoinactivation against the broad spectrum of viruses and, as a result, increasing the knowledge about dynamics in photoinactivation.
Moreover, it is by sheer coincidence and powerfully amplifies that this research line took root with PhiX174 as its pioneer virus. This is even though medium dependency was present in the photoinactivation of PhiX174, as the authors suggested that similar effects could occur in other viruses. This hypothesis triggers further research to ascertain whether the intermediate dependence noticed is peculiar to PhiX174 or a standard feature for several other viruses (Sommerfeld et al., 2024). Moreover, the need for more studies was pointed out, which would emphasize the requirements for a better understanding of photoinactivation-impacting factors like the medium composition.
Any future effort in this area of research to increase this study’s current level of understanding of virus photoinactivation must be underpinned. This implies that the study further complicates the photoinactivation process, and the medium dependence in photoinactivation is to be investigated, with further complexity to draw general conclusions. This understanding of limitations, therefore, not only shows scientific rigor behind but also paves the way for the findings of the presented research to be built further and thus contributes to knowledge in the field of virus photoinactivation.
Conclusion
In summary, this paper gave a detailed overview of the processes involved in evidence-based research evaluation regarding psychiatric mental health nursing, pinpointing the role of the Psychiatric Mental Health Nurse Practitioner (PMHNP). The paper outlines the methodology for choosing and appraising the research articles, analyzing the research findings, and determining the implications for PMHNP practice. This importance is mirrored in this discourse of the critical evaluation of evidence-based research to inform and enhance practice in psychiatric mental health nursing. PMHNPs can improve care through clinical practices for clients with mental health problems by being up-to-date on findings from the most current research. Further, this process enriches professional development, contributing to the growth of the psychiatric mental health nursing specialty and, therefore, better patient outcomes and the deliverance of mental health care.
References
Anderson, C. E., & Boehm, A. B. (2023). Sunlight Inactivation of Enveloped Viruses in Clear Water. Environmental Science & Technology, 57(50), 21395–21404. https://doi.org/10.1021/acs.est.3c06680
Gomes, M., & Bartolomeu, M. (2022). Photoinactivation of Phage Phi6 as a SARS-CoV-2 Model in Wastewater: Evidence of Efficacy and Safety. Microorganisms, 10(3), 659–659. https://doi.org/10.3390/microorganisms10030659
Hetrick, S. E., & Cox, G. R. (2021). Where to Go from Here? An Exploratory Meta-Analysis of the Most Promising Approaches to Depression Prevention Programs for Children and Adolescents. International Journal of Environmental Research and Public Health, 12(5), 4758–4795. https://doi.org/10.3390/ijerph120504758
Sommerfeld, F., Weyersberg, L., Vatter, P., & Hessling, M. (2024). Photoinactivation of the bacteriophage PhiX174 by UVA radiation and visible light in SM buffer and DMEM-F12. BMC Research Notes, 17(1). https://doi.org/10.1186/s13104-023-06658-8
write