Different regulatory mechanisms of the capsule in hypervirulent Klebsiella pneumonia: “direct” wcaJ variation vs. “indirect” rmpA regulation
IntroductionHypervirulent Klebsiella pneumoniae produce an increased amount of capsular substance and are associated with a hypermucoviscous phenotype. Capsule production is regulated by capsular regulatory genes and capsular gene cluster variations. In the present study, we focus on the effect of r...
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Frontiers Media S.A.
2023-04-01
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| Series: | Frontiers in Cellular and Infection Microbiology |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fcimb.2023.1108818/full |
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| author | Weiwen Wang Dongxing Tian Dakang Hu Wenjie Chen Ying Zhou Xiaofei Jiang |
| author_facet | Weiwen Wang Dongxing Tian Dakang Hu Wenjie Chen Ying Zhou Xiaofei Jiang |
| author_sort | Weiwen Wang |
| collection | DOAJ |
| description | IntroductionHypervirulent Klebsiella pneumoniae produce an increased amount of capsular substance and are associated with a hypermucoviscous phenotype. Capsule production is regulated by capsular regulatory genes and capsular gene cluster variations. In the present study, we focus on the effect of rmpA and wcaJon capsule biosynthesis.MethodsPhylogenetic trees were constructed to analyze wcaJ and rmpA sequence diversity in different serotypes hypervirulent strains. Then mutant strains (K2044ΔwcaJ, K2044K1wcaJ, K2044K2wcaJand K2044K64wcaJ) were used to verify the effects of wcaJ and its diversity on capsule synthesis and strain virulence. Furthmore, the role of rmpA in capsular synthesis and its mechanisms were detected in K2044ΔrmpA strain.ResultsRmpA sequences are conversed in different serotypes. And rmpA promoted the production of hypercapsules by simultaneously acting on three promoters in cps cluster. Whereas wcaJ, its sequences are different in different serotypes, and its loss result in the termination of capsular synthesis. Moreover, the results verified that K2 wcaJ could form hypercapsule in K2044 strains (K1 serotype), but K64 wcaJ could not.DiscussionThe interaction of multiple factors is involved in capsule synthesis, including wcaJ and rmpA. RmpA, an known conserved capsular regulator gene, acts on cps cluster promoters to promote the production of the hypercapsule. WcaJ as initiating enzyme of CPS biosynthesis, its presence determines the synthesis of capsule. Besides, different from rmpA, wcaJ sequence consistency is limited to the same serotype, which cause wcaJ functioning in different serotype strains with sequence recognition specificity. |
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| language | English |
| last_indexed | 2024-04-09T16:06:01Z |
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| series | Frontiers in Cellular and Infection Microbiology |
| spelling | doaj.art-20313fcb1eda4b01ab0b543929e0212c2023-04-25T05:05:47ZengFrontiers Media S.A.Frontiers in Cellular and Infection Microbiology2235-29882023-04-011310.3389/fcimb.2023.11088181108818Different regulatory mechanisms of the capsule in hypervirulent Klebsiella pneumonia: “direct” wcaJ variation vs. “indirect” rmpA regulationWeiwen Wang0Dongxing Tian1Dakang Hu2Wenjie Chen3Ying Zhou4Xiaofei Jiang5Department of Clinical Laboratory, Huashan Hospital of Fudan University, Shanghai, ChinaDepartment of Laboratory Medicine, Affiliated Hospital of Jining Medical University, Jining, ChinaDepartment of Laboratory Medicine, Taizhou Municipal Hospital, Taizhou, ChinaDepartment of Infectious Disease, Huashan Hospital of Fudan University, Shanghai, ChinaDepartment of Clinical Laboratory, Shanghai Pulmonary Hospital of Tongji University, Shanghai, ChinaDepartment of Clinical Laboratory, Huashan Hospital of Fudan University, Shanghai, ChinaIntroductionHypervirulent Klebsiella pneumoniae produce an increased amount of capsular substance and are associated with a hypermucoviscous phenotype. Capsule production is regulated by capsular regulatory genes and capsular gene cluster variations. In the present study, we focus on the effect of rmpA and wcaJon capsule biosynthesis.MethodsPhylogenetic trees were constructed to analyze wcaJ and rmpA sequence diversity in different serotypes hypervirulent strains. Then mutant strains (K2044ΔwcaJ, K2044K1wcaJ, K2044K2wcaJand K2044K64wcaJ) were used to verify the effects of wcaJ and its diversity on capsule synthesis and strain virulence. Furthmore, the role of rmpA in capsular synthesis and its mechanisms were detected in K2044ΔrmpA strain.ResultsRmpA sequences are conversed in different serotypes. And rmpA promoted the production of hypercapsules by simultaneously acting on three promoters in cps cluster. Whereas wcaJ, its sequences are different in different serotypes, and its loss result in the termination of capsular synthesis. Moreover, the results verified that K2 wcaJ could form hypercapsule in K2044 strains (K1 serotype), but K64 wcaJ could not.DiscussionThe interaction of multiple factors is involved in capsule synthesis, including wcaJ and rmpA. RmpA, an known conserved capsular regulator gene, acts on cps cluster promoters to promote the production of the hypercapsule. WcaJ as initiating enzyme of CPS biosynthesis, its presence determines the synthesis of capsule. Besides, different from rmpA, wcaJ sequence consistency is limited to the same serotype, which cause wcaJ functioning in different serotype strains with sequence recognition specificity.https://www.frontiersin.org/articles/10.3389/fcimb.2023.1108818/fullcapsulewcaJrmpAVirulencehypervirulent Klebsiella pneumoniae |
| spellingShingle | Weiwen Wang Dongxing Tian Dakang Hu Wenjie Chen Ying Zhou Xiaofei Jiang Different regulatory mechanisms of the capsule in hypervirulent Klebsiella pneumonia: “direct” wcaJ variation vs. “indirect” rmpA regulation Frontiers in Cellular and Infection Microbiology capsule wcaJ rmpA Virulence hypervirulent Klebsiella pneumoniae |
| title | Different regulatory mechanisms of the capsule in hypervirulent Klebsiella pneumonia: “direct” wcaJ variation vs. “indirect” rmpA regulation |
| title_full | Different regulatory mechanisms of the capsule in hypervirulent Klebsiella pneumonia: “direct” wcaJ variation vs. “indirect” rmpA regulation |
| title_fullStr | Different regulatory mechanisms of the capsule in hypervirulent Klebsiella pneumonia: “direct” wcaJ variation vs. “indirect” rmpA regulation |
| title_full_unstemmed | Different regulatory mechanisms of the capsule in hypervirulent Klebsiella pneumonia: “direct” wcaJ variation vs. “indirect” rmpA regulation |
| title_short | Different regulatory mechanisms of the capsule in hypervirulent Klebsiella pneumonia: “direct” wcaJ variation vs. “indirect” rmpA regulation |
| title_sort | different regulatory mechanisms of the capsule in hypervirulent klebsiella pneumonia direct wcaj variation vs indirect rmpa regulation |
| topic | capsule wcaJ rmpA Virulence hypervirulent Klebsiella pneumoniae |
| url | https://www.frontiersin.org/articles/10.3389/fcimb.2023.1108818/full |
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