Label-Free Raman Microspectroscopy for Identifying Prokaryotic Virocells
ABSTRACT Raman microspectroscopy has been used to thoroughly assess growth dynamics and heterogeneity of prokaryotic cells, yet little is known about how the chemistry of individual cells changes during infection with virulent viruses, resulting in so-called virocells. Here, we investigate biochemic...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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American Society for Microbiology
2022-02-01
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| Series: | mSystems |
| Subjects: | |
| Online Access: | https://journals.asm.org/doi/10.1128/msystems.01505-21 |
| _version_ | 1819281823069372416 |
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| author | Indra Monsees Victoria Turzynski Sarah P. Esser André Soares Lara I. Timmermann Katrin Weidenbach Jarno Banas Michael Kloster Bánk Beszteri Ruth A. Schmitz Alexander J. Probst |
| author_facet | Indra Monsees Victoria Turzynski Sarah P. Esser André Soares Lara I. Timmermann Katrin Weidenbach Jarno Banas Michael Kloster Bánk Beszteri Ruth A. Schmitz Alexander J. Probst |
| author_sort | Indra Monsees |
| collection | DOAJ |
| description | ABSTRACT Raman microspectroscopy has been used to thoroughly assess growth dynamics and heterogeneity of prokaryotic cells, yet little is known about how the chemistry of individual cells changes during infection with virulent viruses, resulting in so-called virocells. Here, we investigate biochemical changes of bacterial and archaeal cells of three different species in laboratory cultures before and after addition of their respective viruses using single-cell Raman microspectroscopy. By applying multivariate statistics, we identified significant differences in the spectra of single cells with/without addition of virulent dsRNA phage (phi6) for Pseudomonas syringae. A general ratio of wavenumbers that contributed the greatest differences in the recorded spectra was defined as an indicator for virocells. Based on reference spectra, this difference is likely attributable to an increase in nucleic acid versus protein ratio of virocells. This method also proved successful for identification of Bacillus subtilis cells infected with the double-stranded DNA (dsDNA) phage phi29, displaying a decrease in respective ratio, but failed for archaeal virocells (Methanosarcina mazei with the dsDNA methanosarcina spherical virus) due to autofluorescence. Multivariate and univariate analyses suggest that Raman spectral data of infected cells can also be used to explore the complex biology behind viral infections of bacteria. Using this method, we confirmed the previously described two-stage infection of P. syringae’s phi6 and that infection of B. subtilis with phi29 results in a stress response within single cells. We conclude that Raman microspectroscopy is a promising tool for chemical identification of Gram-positive and Gram-negative virocells undergoing infection with virulent DNA or RNA viruses. IMPORTANCE Viruses are highly diverse biological entities shaping many ecosystems across Earth. However, understanding the infection of individual microbial cells and the related biochemical changes remains limited. Using Raman microspectroscopy in conjunction with univariate and multivariate statistics, we established a marker for identification of infected Gram-positive and Gram-negative bacteria. This nondestructive, label-free analytical method at single-cell resolution paves the way for future studies geared towards analyzing virus-host systems of prokaryotes to further understand the complex chemistry and function of virocells. |
| first_indexed | 2024-12-24T01:05:48Z |
| format | Article |
| id | doaj.art-a42f89bc9f4245e18bd9adeed4cf7320 |
| institution | Directory Open Access Journal |
| issn | 2379-5077 |
| language | English |
| last_indexed | 2024-12-24T01:05:48Z |
| publishDate | 2022-02-01 |
| publisher | American Society for Microbiology |
| record_format | Article |
| series | mSystems |
| spelling | doaj.art-a42f89bc9f4245e18bd9adeed4cf73202022-12-21T17:23:13ZengAmerican Society for MicrobiologymSystems2379-50772022-02-017110.1128/msystems.01505-21Label-Free Raman Microspectroscopy for Identifying Prokaryotic VirocellsIndra Monsees0Victoria Turzynski1Sarah P. Esser2André Soares3Lara I. Timmermann4Katrin Weidenbach5Jarno Banas6Michael Kloster7Bánk Beszteri8Ruth A. Schmitz9Alexander J. Probst10Group for Aquatic Microbial Ecology, Environmental Microbiology and Biotechnology, University Duisburg-Essen, Essen, GermanyGroup for Aquatic Microbial Ecology, Environmental Microbiology and Biotechnology, University Duisburg-Essen, Essen, GermanyGroup for Aquatic Microbial Ecology, Environmental Microbiology and Biotechnology, University Duisburg-Essen, Essen, GermanyGroup for Aquatic Microbial Ecology, Environmental Microbiology and Biotechnology, University Duisburg-Essen, Essen, GermanyGroup for Aquatic Microbial Ecology, Environmental Microbiology and Biotechnology, University Duisburg-Essen, Essen, GermanyInstitute for General Microbiology, Christian Albrechts University, Kiel, GermanyEssen, GermanyPhycology Group, Faculty of Biology, University Duisburg-Essen, Essen, GermanyPhycology Group, Faculty of Biology, University Duisburg-Essen, Essen, GermanyInstitute for General Microbiology, Christian Albrechts University, Kiel, GermanyGroup for Aquatic Microbial Ecology, Environmental Microbiology and Biotechnology, University Duisburg-Essen, Essen, GermanyABSTRACT Raman microspectroscopy has been used to thoroughly assess growth dynamics and heterogeneity of prokaryotic cells, yet little is known about how the chemistry of individual cells changes during infection with virulent viruses, resulting in so-called virocells. Here, we investigate biochemical changes of bacterial and archaeal cells of three different species in laboratory cultures before and after addition of their respective viruses using single-cell Raman microspectroscopy. By applying multivariate statistics, we identified significant differences in the spectra of single cells with/without addition of virulent dsRNA phage (phi6) for Pseudomonas syringae. A general ratio of wavenumbers that contributed the greatest differences in the recorded spectra was defined as an indicator for virocells. Based on reference spectra, this difference is likely attributable to an increase in nucleic acid versus protein ratio of virocells. This method also proved successful for identification of Bacillus subtilis cells infected with the double-stranded DNA (dsDNA) phage phi29, displaying a decrease in respective ratio, but failed for archaeal virocells (Methanosarcina mazei with the dsDNA methanosarcina spherical virus) due to autofluorescence. Multivariate and univariate analyses suggest that Raman spectral data of infected cells can also be used to explore the complex biology behind viral infections of bacteria. Using this method, we confirmed the previously described two-stage infection of P. syringae’s phi6 and that infection of B. subtilis with phi29 results in a stress response within single cells. We conclude that Raman microspectroscopy is a promising tool for chemical identification of Gram-positive and Gram-negative virocells undergoing infection with virulent DNA or RNA viruses. IMPORTANCE Viruses are highly diverse biological entities shaping many ecosystems across Earth. However, understanding the infection of individual microbial cells and the related biochemical changes remains limited. Using Raman microspectroscopy in conjunction with univariate and multivariate statistics, we established a marker for identification of infected Gram-positive and Gram-negative bacteria. This nondestructive, label-free analytical method at single-cell resolution paves the way for future studies geared towards analyzing virus-host systems of prokaryotes to further understand the complex chemistry and function of virocells.https://journals.asm.org/doi/10.1128/msystems.01505-21bacteriophagephagephi29phi6virus |
| spellingShingle | Indra Monsees Victoria Turzynski Sarah P. Esser André Soares Lara I. Timmermann Katrin Weidenbach Jarno Banas Michael Kloster Bánk Beszteri Ruth A. Schmitz Alexander J. Probst Label-Free Raman Microspectroscopy for Identifying Prokaryotic Virocells mSystems bacteriophage phage phi29 phi6 virus |
| title | Label-Free Raman Microspectroscopy for Identifying Prokaryotic Virocells |
| title_full | Label-Free Raman Microspectroscopy for Identifying Prokaryotic Virocells |
| title_fullStr | Label-Free Raman Microspectroscopy for Identifying Prokaryotic Virocells |
| title_full_unstemmed | Label-Free Raman Microspectroscopy for Identifying Prokaryotic Virocells |
| title_short | Label-Free Raman Microspectroscopy for Identifying Prokaryotic Virocells |
| title_sort | label free raman microspectroscopy for identifying prokaryotic virocells |
| topic | bacteriophage phage phi29 phi6 virus |
| url | https://journals.asm.org/doi/10.1128/msystems.01505-21 |
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