Effects of gallic acid on capsular polysaccharide biosynthesis in Klebsiella pneumoniae
Background: Klebsiella pneumoniae is a gram-negative opportunistic pathogen that causes diseases mostly in immunocompromised individuals. Recently, hypervirulent K. pneumoniae strains also cause severe disease in healthy individuals. Capsular polysaccharide (CPS) is the major virulence determinant i...
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| Format: | Article |
| Language: | English |
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Elsevier
2022-12-01
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| Series: | Journal of Microbiology, Immunology and Infection |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S1684118221001419 |
| _version_ | 1797995168740147200 |
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| author | Tien-Huang Lin Chien-Chen Wu Cheng-Yin Tseng Jing-Han Fang Ching-Ting Lin |
| author_facet | Tien-Huang Lin Chien-Chen Wu Cheng-Yin Tseng Jing-Han Fang Ching-Ting Lin |
| author_sort | Tien-Huang Lin |
| collection | DOAJ |
| description | Background: Klebsiella pneumoniae is a gram-negative opportunistic pathogen that causes diseases mostly in immunocompromised individuals. Recently, hypervirulent K. pneumoniae strains also cause severe disease in healthy individuals. Capsular polysaccharide (CPS) is the major virulence determinant in hypervirulent K. pneumoniae and protects the cell against the bactericidal activity of the immune system. Gallic acid (GA), a natural phenolic compound, is known to exhibit wide spectrum antibacterial activity; however, its effect on hypervirulent K. pneumoniae remains largely unresolved. We aimed to identify the effects of GA on CPS biosynthesis in hypervirulent K. pneumoniae. Methods: Antibacterial activity of GA was evaluated by counting colonies. CPS amount was determined by glucuronic acid content. The transcriptions of cps gene cluster were measured by quantitative real time PCR (qRT-PCR) and the β-galactosidase activity. The effect of GA on the resistance of K. pneumoniae to streptonigrin (SNG), an iron-activated antibiotic, was evaluated. The effect of GA on the resistance of K. pneumoniae to serum killing and phagocytosis by macrophages was observed. Results: GA inhibited the growth and CPS biosynthesis in K. pneumoniae. GA may affect the iron availability in K. pneumoniae, thus possibly repressing the cps transcription. In addition, GA reduced the resistance of K. pneumoniae to serum killing and enhanced its susceptibility to phagocytosis. Conclusion: GA possesses bactericidal activity and inhibits the CPS biosynthesis in hypervirulent K. pneumoniae, thereby facilitating pathogen clearance by the host immune system. Therefore, GA may represent a promising strategy for the prevention or treatment of patients with hypervirulent K. pneumoniae infections. |
| first_indexed | 2024-04-11T09:57:09Z |
| format | Article |
| id | doaj.art-565a23aca83d420d82527420d2589237 |
| institution | Directory Open Access Journal |
| issn | 1684-1182 |
| language | English |
| last_indexed | 2024-04-11T09:57:09Z |
| publishDate | 2022-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Microbiology, Immunology and Infection |
| spelling | doaj.art-565a23aca83d420d82527420d25892372022-12-22T04:30:32ZengElsevierJournal of Microbiology, Immunology and Infection1684-11822022-12-0155612551262Effects of gallic acid on capsular polysaccharide biosynthesis in Klebsiella pneumoniaeTien-Huang Lin0Chien-Chen Wu1Cheng-Yin Tseng2Jing-Han Fang3Ching-Ting Lin4Division of Urology, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung, Taiwan; Post-Baccalaureate Chinese Medicine, Tzu Chi University, Hualien, TaiwanInstitute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, TaiwanGraduate Institute of Chinese Medicine, China Medical University, Taichung, Taiwan; Section of Infectious Disease, Hsinchu Mackay Memorial Hospital, Hsinchu, TaiwanSchool of Post-Baccalaureate Chinese Medicine, China Medical University, Taichung, TaiwanSchool of Chinese Medicine, China Medical University, Taichung, Taiwan; Corresponding author. School of Chinese Medicine, China Medical University, 91 Hsueh-Shih Rd, Taichung City, 40402, Taiwan. Fax: +886 4 22032295.Background: Klebsiella pneumoniae is a gram-negative opportunistic pathogen that causes diseases mostly in immunocompromised individuals. Recently, hypervirulent K. pneumoniae strains also cause severe disease in healthy individuals. Capsular polysaccharide (CPS) is the major virulence determinant in hypervirulent K. pneumoniae and protects the cell against the bactericidal activity of the immune system. Gallic acid (GA), a natural phenolic compound, is known to exhibit wide spectrum antibacterial activity; however, its effect on hypervirulent K. pneumoniae remains largely unresolved. We aimed to identify the effects of GA on CPS biosynthesis in hypervirulent K. pneumoniae. Methods: Antibacterial activity of GA was evaluated by counting colonies. CPS amount was determined by glucuronic acid content. The transcriptions of cps gene cluster were measured by quantitative real time PCR (qRT-PCR) and the β-galactosidase activity. The effect of GA on the resistance of K. pneumoniae to streptonigrin (SNG), an iron-activated antibiotic, was evaluated. The effect of GA on the resistance of K. pneumoniae to serum killing and phagocytosis by macrophages was observed. Results: GA inhibited the growth and CPS biosynthesis in K. pneumoniae. GA may affect the iron availability in K. pneumoniae, thus possibly repressing the cps transcription. In addition, GA reduced the resistance of K. pneumoniae to serum killing and enhanced its susceptibility to phagocytosis. Conclusion: GA possesses bactericidal activity and inhibits the CPS biosynthesis in hypervirulent K. pneumoniae, thereby facilitating pathogen clearance by the host immune system. Therefore, GA may represent a promising strategy for the prevention or treatment of patients with hypervirulent K. pneumoniae infections.http://www.sciencedirect.com/science/article/pii/S1684118221001419Hypervirulent Klebsiella pneumoniaeGallic acidCapsular polysaccharideAntimicrobial agent |
| spellingShingle | Tien-Huang Lin Chien-Chen Wu Cheng-Yin Tseng Jing-Han Fang Ching-Ting Lin Effects of gallic acid on capsular polysaccharide biosynthesis in Klebsiella pneumoniae Journal of Microbiology, Immunology and Infection Hypervirulent Klebsiella pneumoniae Gallic acid Capsular polysaccharide Antimicrobial agent |
| title | Effects of gallic acid on capsular polysaccharide biosynthesis in Klebsiella pneumoniae |
| title_full | Effects of gallic acid on capsular polysaccharide biosynthesis in Klebsiella pneumoniae |
| title_fullStr | Effects of gallic acid on capsular polysaccharide biosynthesis in Klebsiella pneumoniae |
| title_full_unstemmed | Effects of gallic acid on capsular polysaccharide biosynthesis in Klebsiella pneumoniae |
| title_short | Effects of gallic acid on capsular polysaccharide biosynthesis in Klebsiella pneumoniae |
| title_sort | effects of gallic acid on capsular polysaccharide biosynthesis in klebsiella pneumoniae |
| topic | Hypervirulent Klebsiella pneumoniae Gallic acid Capsular polysaccharide Antimicrobial agent |
| url | http://www.sciencedirect.com/science/article/pii/S1684118221001419 |
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