ClpP participates in stress tolerance, biofilm formation, antimicrobial tolerance, and virulence of Enterococcus faecalis

• DOI: 10.21203/rs.2.11200/v3
• Publication Date: 2020-02-04T15:47:35Z
• Authors: Jinxin Zheng; Yang Wu; Zhiwei Lin; Guangfu Wang; Sibo Jiang; Xiang Sun; Haopeng Tu; Zhi-jian Yu; Di Qu
• Keywords: ClpP; Proteomics; 0301 basic medicine; Virulence; Stress tolerance; Antimicrobial tolerance; Linezolid; Minocycline; Endopeptidase Clp; 16. Peace & justice; Microbiology; QR1-502; Anti-Bacterial Agents; 03 medical and health sciences; Bacterial Proteins; Stress, Physiological; Tandem Mass Spectrometry; Biofilms; Drug Resistance, Bacterial; Enterococcus faecalis; Biofilm formation; Gene Deletion; Research Article

Abstract Background ClpP is important for bacterial growth and plays an indispensable role in cellular protein quality control systems by refolding or degrading damaged proteins, but the physiological significance of ClpP in Enterococcus faecalis remains obscure. A clpP deletion mutant (△ clpP ) was constructed using the E. faecalis OG1RF strain to clarify the effect of ClpP on E. faecalis. The global abundance of proteins was determined by a mass spectrometer with tandem mass tag labeling. Results The Δ clpP mutant strain showed impaired growth at 20°C or 45°C at 5% NaCl or 2 mM H 2 O 2 . The number of surviving Δ clpP mutants decreased after exposure to the high concentration (50× minimal inhibitory concentration) of linezolid or minocycline for 96 h. The Δ clpP mutant strain also demonstrated decreased biofilm formation but increased virulence in a Galleria mellonella model. The mass spectrometry proteomics data indicated that the abundances of 135 proteins changed (111 increased, 24 decreased) in the Δ clpP mutant strain. Among those, the abundances of stress response or virulence relating proteins: FsrA response regulator, gelatinase GelE, regulatory protein Spx ( spxA ), heat-inducible transcription repressor HrcA, transcriptional regulator CtsR, ATPase/chaperone ClpC, acetyl esterase/lipase, and chaperonin GroEL increased in the Δ clpP mutant strain; however, the abundances of ribosomal protein L4/L1 family protein ( rplD ), ribosomal protein L7/L12 ( rplL2 ), 50S ribosomal protein L13 ( rplM ), L18 ( rplR ), L20 ( rplT ), 30S ribosomal protein S14 ( rpsN2 ) and S18 ( rpsR ) all decreased. The abundances of biofilm formation-related adapter protein MecA increased, while the abundances of dihydroorotase ( pyrC ), orotate phosphoribosyltransferase ( pyrE ), and orotidine-5'-phosphate decarboxylase ( pyrF ) all decreased in the Δ clpP mutant strain. Conclusion The present study demonstrates that ClpP participates in stress tolerance, biofilm formation, antimicrobial tolerance, and virulence of E. faecalis.