The Kiss of Death: Serratia marcescens Antibacterial Activities against Staphylococcus aureus Requires Both de novo Prodigiosin Synthesis and Direct Contact
ABSTRACT Prodigiosin possesses antibacterial activities, but as a highly hydrophobic compound, it raised the question about how Serratia marcescens introduce this compound to other microbes. Here, we demonstrate that the production of prodigiosin by newly isolated S. marcescens RH10 correlates with...
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| Format: | Article |
| Language: | English |
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American Society for Microbiology
2022-06-01
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| Series: | Microbiology Spectrum |
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| Online Access: | https://journals.asm.org/doi/10.1128/spectrum.00607-22 |
| _version_ | 1811238094374961152 |
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| author | Sungbin Lim Jihun Bhak Sungwon Jeon Wonsik Mun Jong Bhak Seong Yeol Choi Robert J. Mitchell |
| author_facet | Sungbin Lim Jihun Bhak Sungwon Jeon Wonsik Mun Jong Bhak Seong Yeol Choi Robert J. Mitchell |
| author_sort | Sungbin Lim |
| collection | DOAJ |
| description | ABSTRACT Prodigiosin possesses antibacterial activities, but as a highly hydrophobic compound, it raised the question about how Serratia marcescens introduce this compound to other microbes. Here, we demonstrate that the production of prodigiosin by newly isolated S. marcescens RH10 correlates with its antibacterial activity against a multidrug-resistant strain of S. aureus, with this pathogen’s viability decreasing 6-log over 24 h. While S. marcescens RH10 does secrete membrane vesicles that carry prodigiosin, this antibiotic was not active in this form, with 5 mg/L prodigiosin leading to only a 1.22-fold reduction in the S. aureus viability while the same quantity of purified prodigiosin led to a 2800-fold reduction. Contact assays, however, showed increased activity, with a 3-log loss in the S. aureus viabilities in only 6 h as long as de novo production of prodigiosin occurred. The role of prodigiosin was confirmed further by generating an isogenic ΔpigA mutant in S. marcescens RH10, based on the draft genome sequence reported here, to inhibit the synthesis of prodigiosin. In all experiments performed, this mutant was unable to kill S. aureus. Finally, the possibility that the type VI secretion system present in S. marcescens may also be important was also explored as it is known to be used by this strain to kill other microbes. The results here, however, found no obvious activity against S. aureus. In conclusion, the results presented here show prodigiosin requires both cell-to-cell contact and de novo synthesis for it to be effective as an antibiotic for its native host. IMPORTANCE The antibacterial activities of prodigiosin are well-established but, as a hydrophobic molecule, the mechanisms used to introduce it to susceptible microbes has never been studied. We found here, in contrast to violacein, another hydrophobic antibiotic that can be transferred using membrane vesicles (MVs), prodigiosin is also carried from Serratia marcescens in MVs released but its resulting activities were severely mitigated compared to the freely added compound, suggesting it is more tightly bound to the MVs than violacein. This led us to hypothesize that cell-to-cell contact is needed, which we demonstrate here. As well, we show de novo synthesis of prodigiosin is needed for it to be effective. As violacein- and prodigiosin-producing bacterial strains are both beneficial to amphibians, where they help protect the skin against pathogens, the findings presented here provide an important ecological perspective as they show the mechanisms used differ according to the antibacterial produced. |
| first_indexed | 2024-04-12T12:35:46Z |
| format | Article |
| id | doaj.art-f1fb9f8a561f4542a851a4bd545626b1 |
| institution | Directory Open Access Journal |
| issn | 2165-0497 |
| language | English |
| last_indexed | 2024-04-12T12:35:46Z |
| publishDate | 2022-06-01 |
| publisher | American Society for Microbiology |
| record_format | Article |
| series | Microbiology Spectrum |
| spelling | doaj.art-f1fb9f8a561f4542a851a4bd545626b12022-12-22T03:32:54ZengAmerican Society for MicrobiologyMicrobiology Spectrum2165-04972022-06-0110310.1128/spectrum.00607-22The Kiss of Death: Serratia marcescens Antibacterial Activities against Staphylococcus aureus Requires Both de novo Prodigiosin Synthesis and Direct ContactSungbin Lim0Jihun Bhak1Sungwon Jeon2Wonsik Mun3Jong Bhak4Seong Yeol Choi5Robert J. Mitchell6Department of Biological Sciences, Ulsan National institute of Science and Technology (UNIST), Ulsan, South KoreaDepartment of Biomedical Engineering, Ulsan National institute of Science and Technology (UNIST), Ulsan, South KoreaClinomics Inc., Ulsan, South KoreaDepartment of Biological Sciences, Ulsan National institute of Science and Technology (UNIST), Ulsan, South KoreaDepartment of Biomedical Engineering, Ulsan National institute of Science and Technology (UNIST), Ulsan, South KoreaDepartment of Biological Sciences, Ulsan National institute of Science and Technology (UNIST), Ulsan, South KoreaDepartment of Biological Sciences, Ulsan National institute of Science and Technology (UNIST), Ulsan, South KoreaABSTRACT Prodigiosin possesses antibacterial activities, but as a highly hydrophobic compound, it raised the question about how Serratia marcescens introduce this compound to other microbes. Here, we demonstrate that the production of prodigiosin by newly isolated S. marcescens RH10 correlates with its antibacterial activity against a multidrug-resistant strain of S. aureus, with this pathogen’s viability decreasing 6-log over 24 h. While S. marcescens RH10 does secrete membrane vesicles that carry prodigiosin, this antibiotic was not active in this form, with 5 mg/L prodigiosin leading to only a 1.22-fold reduction in the S. aureus viability while the same quantity of purified prodigiosin led to a 2800-fold reduction. Contact assays, however, showed increased activity, with a 3-log loss in the S. aureus viabilities in only 6 h as long as de novo production of prodigiosin occurred. The role of prodigiosin was confirmed further by generating an isogenic ΔpigA mutant in S. marcescens RH10, based on the draft genome sequence reported here, to inhibit the synthesis of prodigiosin. In all experiments performed, this mutant was unable to kill S. aureus. Finally, the possibility that the type VI secretion system present in S. marcescens may also be important was also explored as it is known to be used by this strain to kill other microbes. The results here, however, found no obvious activity against S. aureus. In conclusion, the results presented here show prodigiosin requires both cell-to-cell contact and de novo synthesis for it to be effective as an antibiotic for its native host. IMPORTANCE The antibacterial activities of prodigiosin are well-established but, as a hydrophobic molecule, the mechanisms used to introduce it to susceptible microbes has never been studied. We found here, in contrast to violacein, another hydrophobic antibiotic that can be transferred using membrane vesicles (MVs), prodigiosin is also carried from Serratia marcescens in MVs released but its resulting activities were severely mitigated compared to the freely added compound, suggesting it is more tightly bound to the MVs than violacein. This led us to hypothesize that cell-to-cell contact is needed, which we demonstrate here. As well, we show de novo synthesis of prodigiosin is needed for it to be effective. As violacein- and prodigiosin-producing bacterial strains are both beneficial to amphibians, where they help protect the skin against pathogens, the findings presented here provide an important ecological perspective as they show the mechanisms used differ according to the antibacterial produced.https://journals.asm.org/doi/10.1128/spectrum.00607-22Serratia marcescensStaphylococcus aureusprodigiosinmembrane vesiclestype VI secretion systemde novo assembly |
| spellingShingle | Sungbin Lim Jihun Bhak Sungwon Jeon Wonsik Mun Jong Bhak Seong Yeol Choi Robert J. Mitchell The Kiss of Death: Serratia marcescens Antibacterial Activities against Staphylococcus aureus Requires Both de novo Prodigiosin Synthesis and Direct Contact Microbiology Spectrum Serratia marcescens Staphylococcus aureus prodigiosin membrane vesicles type VI secretion system de novo assembly |
| title | The Kiss of Death: Serratia marcescens Antibacterial Activities against Staphylococcus aureus Requires Both de novo Prodigiosin Synthesis and Direct Contact |
| title_full | The Kiss of Death: Serratia marcescens Antibacterial Activities against Staphylococcus aureus Requires Both de novo Prodigiosin Synthesis and Direct Contact |
| title_fullStr | The Kiss of Death: Serratia marcescens Antibacterial Activities against Staphylococcus aureus Requires Both de novo Prodigiosin Synthesis and Direct Contact |
| title_full_unstemmed | The Kiss of Death: Serratia marcescens Antibacterial Activities against Staphylococcus aureus Requires Both de novo Prodigiosin Synthesis and Direct Contact |
| title_short | The Kiss of Death: Serratia marcescens Antibacterial Activities against Staphylococcus aureus Requires Both de novo Prodigiosin Synthesis and Direct Contact |
| title_sort | kiss of death serratia marcescens antibacterial activities against staphylococcus aureus requires both de novo prodigiosin synthesis and direct contact |
| topic | Serratia marcescens Staphylococcus aureus prodigiosin membrane vesicles type VI secretion system de novo assembly |
| url | https://journals.asm.org/doi/10.1128/spectrum.00607-22 |
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