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Jacob C, Student J, Bridges DF, Chu W, Porwollik S, McClelland M, Melotto M. Intraspecies competition among Salmonella enterica isolates in the lettuce leaf apoplast. FRONTIERS IN PLANT SCIENCE 2024; 15:1302047. [PMID: 38352648 PMCID: PMC10861783 DOI: 10.3389/fpls.2024.1302047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 01/08/2024] [Indexed: 02/16/2024]
Abstract
Multiple Salmonella enterica serovars and strains have been reported to be able to persist inside the foliar tissue of lettuce (Lactuca sativa L.), potentially resisting washing steps and reaching the consumer. Intraspecies variation of the bacterial pathogen and of the plant host can both significantly affect the outcome of foliar colonization. However, current understanding of the mechanisms underlying this phenomenon is still very limited. In this study, we evaluated the foliar fitness of 14 genetically barcoded S. enterica isolates from 10 different serovars, collected from plant and animal sources. The S. enterica isolates were vacuum-infiltrated individually or in pools into the leaves of three- to four-week-old lettuce plants. To estimate the survival capacity of individual isolates, we enumerated the bacterial populations at 0- and 10- days post-inoculation (DPI) and calculated their net growth. The competition of isolates in the lettuce apoplast was assessed through the determination of the relative abundance change of barcode counts of each isolate within pools during the 10 DPI experimental period. Isolates exhibiting varying apoplast fitness phenotypes were used to evaluate their capacity to grow in metabolites extracted from the lettuce apoplast and to elicit the reactive oxygen species burst immune response. Our study revealed that strains of S. enterica can substantially differ in their ability to survive and compete in a co-inhabited lettuce leaf apoplast. The differential foliar fitness observed among these S. enterica isolates might be explained, in part, by their ability to utilize nutrients available in the apoplast and to evade plant immune responses in this niche.
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Affiliation(s)
- Cristián Jacob
- Departamento de Ciencias Vegetales, Facultad de Agronomía y Sistemas Naturales, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Joseph Student
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
- Horticulture and Agronomy Graduate Program, University of California, Davis, Davis, CA, United States
| | - David F. Bridges
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
- Plant Biology Graduate Group, University of California, Davis, Davis, CA, United States
| | - Weiping Chu
- Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA, United States
| | - Steffen Porwollik
- Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA, United States
| | - Michael McClelland
- Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA, United States
| | - Maeli Melotto
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
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Jeong GJ, Khan F, Tabassum N, Kim YM. Cellular and physiological roles of sigma factors in Vibrio spp.: A comprehensive review. Int J Biol Macromol 2024; 254:127833. [PMID: 37918595 DOI: 10.1016/j.ijbiomac.2023.127833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 10/30/2023] [Accepted: 10/30/2023] [Indexed: 11/04/2023]
Abstract
Vibrio species are motile gram-negative bacteria commonly found in aquatic environments. Vibrio species include pathogenic as well as non-pathogenic strains. Pathogenic Vibrio species have been reported in invertebrates and humans, whereas non-pathogenic strains are involved in symbiotic relationships with their eukaryotic hosts. These bacteria are also able to adapt to fluctuations in temperature, salinity, and pH, in addition to oxidative stress, and osmotic pressure in aquatic ecosystems. Moreover, they have also developed protective mechanisms against the immune systems of their hosts. Vibrio species accomplish adaptation to changing environments outside or inside the host by altering their gene expression profiles. To this end, several sigma factors specifically regulate gene expression, particularly under stressful environmental conditions. Moreover, other sigma factors are associated with biofilm formation and virulence as well. This review discusses different types of sigma and anti-sigma factors of Vibrio species involved in virulence and regulation of gene expression upon changes in environmental conditions. The evolutionary relationships between sigma factors with various physiological roles in Vibrio species are also discussed extensively.
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Affiliation(s)
- Geum-Jae Jeong
- Department of Food Science and Technology, Pukyong National University, Busan 48513, Republic of Korea
| | - Fazlurrahman Khan
- Institute of Fisheries Sciences, Pukyong National University, Busan 48513, Republic of Korea; Marine Integrated Biomedical Technology Center, The National Key Research Institutes in Universities, Pukyong National University, Busan 48513, Republic of Korea; Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan 48513, Republic of Korea.
| | - Nazia Tabassum
- Marine Integrated Biomedical Technology Center, The National Key Research Institutes in Universities, Pukyong National University, Busan 48513, Republic of Korea; Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan 48513, Republic of Korea
| | - Young-Mog Kim
- Department of Food Science and Technology, Pukyong National University, Busan 48513, Republic of Korea; Marine Integrated Biomedical Technology Center, The National Key Research Institutes in Universities, Pukyong National University, Busan 48513, Republic of Korea; Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan 48513, Republic of Korea.
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