Related Experiment Video
Updated: Jun 14, 2025

Bacterial Delivery of RNAi Effectors: Transkingdom RNAi
Published on: August 18, 2010
Photodynamic therapy on mRNA levels in bacteria
Bruno Ricardo Barreto Pires1, Flavia de Paoli2, Andre Luiz Mencalha1
1Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Boulevard Vinte e Oito de Setembro, 87, fundos, Vila Isabel, Rio de Janeiro, 20551030, Brazil.
Abstract:
Antimicrobial photodynamic therapy (aPDT) has shown efficacy in inactivating different bacterial species by photosensitizer-induced free radical production. Despite aPDT is considered unable to cause resistant strains, enzymatic pathways for detoxification of reactive oxygen species and transmembrane photosensitizer efflux systems could cause resistance to aPDT. Resistance mechanisms can be evaluated by measurement of mRNA from by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Thus, the aim of this study was to access the mRNA level data obtained by RT-qPCR in bacterial cells submitted to photodynamic therapy. Studies performed on mRNA levels in bacteria after PDT were assessed on MEDLINE/Pubmed. The mRNA levels from genes related to various functions have been successfully evaluated in both Gram-positive and -negative bacteria after aPDT by RT-qPCR. Such an approach has improved the understanding of aPDT-induced effects, and reinforced the effectiveness of aPDT on bacteria, which can cause infections in different human tissues.
Insights
Antimicrobial photodynamic therapy (aPDT) effectively inactivates bacteria. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) can measure bacterial mRNA levels to understand aPDT resistance mechanisms and confirm its effectiveness against infections.
Area of Science:
- Microbiology
- Photochemistry
- Molecular Biology
Background:
- Antimicrobial photodynamic therapy (aPDT) uses photosensitizers and light to generate reactive oxygen species, inactivating bacteria.
- While generally effective, potential bacterial resistance mechanisms like reactive oxygen species detoxification and photosensitizer efflux exist.
- Measuring bacterial mRNA levels offers a way to investigate these resistance mechanisms.
Purpose of the Study:
- To evaluate mRNA levels in bacteria treated with photodynamic therapy (PDT).
- To assess the utility of quantitative reverse transcription polymerase chain reaction (RT-qPCR) in studying aPDT effects on bacteria.
- To understand gene expression changes related to bacterial responses to aPDT.
Main Methods:
- Literature search on MEDLINE/Pubmed for studies measuring mRNA levels in bacteria post-PDT.
- Analysis of RT-qPCR data from bacterial cells exposed to aPDT.
- Evaluation of gene expression related to various cellular functions.
Main Results:
- RT-qPCR successfully measured mRNA levels in both Gram-positive and Gram-negative bacteria after aPDT.
- The study demonstrated the feasibility of assessing gene expression changes in response to aPDT.
- Data indicated aPDT's effectiveness in impacting bacterial gene expression.
Conclusions:
- RT-qPCR is a valuable tool for investigating bacterial responses and potential resistance to aPDT.
- Understanding mRNA level changes enhances the comprehension of aPDT's mechanisms of action.
- This approach reinforces the efficacy of aPDT in combating bacterial infections.
Related Concept Videos
Types of RNA
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
Transcription Attenuation in Prokaryotes
There are several different mechanisms used to attenuate transcription. In ribosome mediated...

