Absence of Protoheme IX Farnesyltransferase CtaB Causes Virulence Attenuation but Enhances Pigment Production and Persister Survival in MRSA

Xu, Tao; Han, Jian; Zhang, Jia; Chen, Jiazhen; Wu, Nan; Zhang, Wenhong; Zhang, Ying

doi:10.3389/fmicb.2016.01625

Cited by 19 publications

(27 citation statements)

References 63 publications

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“…Typically, clinical SCVs and ΔhemB mutants show no or decreased pigment production compared to that of the wild type (20). However, when CtaB, the enzyme that catalyzes the very last step of the pathway and couples the farnesyl diphosphate chain to protoheme IX, is removed in S. aureus, an increased pigmentation is observed, indicating that farnesyl diphosphate is fed into the pigment production pathway (30). Since the insertion into hemY interrupts the pathway between the steps catalyzed by HemB and CtaB, the hemY mutant was supplemented with hemin on an agar plate to assess staphyloxanthin production in the absence and presence of hemin.…”

Section: Resultsmentioning

confidence: 99%

Influence of IS 256 on Genome Variability and Formation of Small-Colony Variants in Staphylococcus aureus

Kleinert

Kallies

Hort

et al. 2017

Antimicrob Agents Chemother

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Staphylococcus aureus has acquired resistance to nearly all antibiotics used in clinical practice. Whereas some resistance mechanisms are conferred by uptake of resistance genes, others evolve by mutation. In this study, IS256 has been shown to play a role, e.g., in S. aureus strains displaying intermediate resistance to vancomycin (VISA). To characterize the IS256 insertion sites in the genomes of two closely related sequence type 247 (ST247) VISA strains, all insertions were mapped in both VISA and a susceptible control strain. The results showed that the three ST247 strains contained the highest number so far of IS256 insertions for all sequenced S. aureus strains. Furthermore, in contrast to the case with the other IS elements in these genomes, the IS256 insertion sites were not identical in the closely related strains, indicating a high transposition frequency of IS256. When IS256 was introduced into a laboratory strain which was then cultured in the presence of antibiotics, it was possible to isolate small-colony variants (SCVs) that possessed IS256 insertions in guaA and hemY that displayed increased resistance to vancomycin and aminoglycosides, respectively. For these clones, a very rapid reversion to the wild type that resembled the fast reversion of clinical SCVs was observed. The reversion was caused by excision of IS256 in a small number of fast-growing clones that quickly outcompeted the SCVs in broth cultures. In conclusion, the presence of IS256 confers a strong genomic plasticity that is useful for adaptation to antibiotic stress.

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Section: Resultsmentioning

confidence: 99%

Influence of IS 256 on Genome Variability and Formation of Small-Colony Variants in Staphylococcus aureus

Kleinert

Kallies

Hort

et al. 2017

Antimicrob Agents Chemother

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“…After terminal repair, base A and sequencing connector were added, the target fragments were collected by agarose gel electrophoresis, and amplified by PCR. The whole library was prepared and the library was sequenced by Illumina HiSeq2500 [21].…”

Section: Rna Isolation Mrna Enrichment and Sequencingmentioning

confidence: 99%

The bacteriostatic effect and mechanism of berberine on Methicillin resistant Staphylococcus aureus in vitro

Wang

Zhou

et al. 2020

Preprint

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Background: To observe the bacteriostatic effect of berberine (BBR) and BBR combined with gentamicin (GEN), levofloxacin (LEV) and amikacin (AMI) on Methicillin resistant Staphylococcus aureus (MRSA), while also exploring the bacteriostatic mechanism of BBR on MRSA. Methods: The minimal inhibitory concentration (MIC) of BBR, GEN, LEV and AMI on 26 clinical MRSA strains was determined by broth microdilution, while the MICs of BBR combined with GEN, LEV and AMI against MRSA were determined using a microdilution checkerboard. Time-killing curves were used to determine the kinetics of BBR combined with antibiotics for MRSA. We used conductivity tests to assess the changes in membrane permeability in response to BBR on MRSA, while also investigating the changes in MRSA morphology by transmission electron microscopy. RNA-sequencing was used to analyze the expression of differentially expressed genes in reference strain USA300 after its treatment with BBR at different concentrations.Results: The MICs range of BBR on 26 strains of MRSA was 32-256 µg/mL. BBR combined with GEN, LEV and AMI had obvious bacteriostatic effect on MASA. After co-culturing MRSA with BBR at 512 ug/mL, 64 ug/mL and 8 ug/mL, respectively, the electrical conductivity increased, compared with the control group, by 8.14%, 13.08% and 12.01%, respectively. Using transmission electron microscopy, we found that low concentration of BBR (8 ug/mL) had no significant effect on MRSA structure (keeping intact), medium concentration of BBR (64 ug/mL) thinned the cell wall of MRSA, while high concentration of BBR (512 ug/mL) induced the destruction and dissolution of MRSA cell wall structure and the leakage of bacterial contents, leading to bacterial lysis. RNA-sequencing results showed that there were 754 differentially expressed genes in the high concentration group compared with the normal control group. Compared with the low concentration group, there were 590 differentially expressed genes in the high concentration group. Compared with the control group, only 19 genes were differentially expressed in the low concentration group. The up-regulated genes are mainly related to the cell wall hydrolysis regulatory genes, while the down-regulated genes are mainly related to the serine protease family.Conclusions: BBR displayed an excellent bacteriostatic effect on MRSA. BBR combined with GEN and AMI significantly enhanced the bacteriostatic effect on MRSA, while BBR combined with LEV showed no significant change in the bacteriostatic effect on MRSA. BBR inhibited bacteria by destroying and dissolving the structure of MRSA cell wall. RNA-sequencing results further demonstrated that the expression of cell wall hydrolysis genes ssaA, lytM and virulence factor serine protease genes were significantly differentially expressed when high concentration BBR treated on MRSA.

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“…Stationary phase S. aureus persister formation is associated with low membrane potential (39), while phenol-soluble modulins limit S. aureus prsister cell formation (40). Deletion of ctaB can attenuate S. aureus growth and virulence in mice but enhanced the formation of persister cells in stationary phase (41).…”

Section: Introductionmentioning

confidence: 99%

“…It has been hypothesized that persister genes may overlap with virulence genes (28, 48). Few studies explored the relationship between virulence and persister formation, and mostly it remains unclear (41). In the present study, we identified by mutant library screen a new transcription factor NWMN_0037 which we named RpvA based on its involvement in both persister formation and virulence in S. aureus .…”

Section: Introductionmentioning

confidence: 99%

A Novel LysR-Type Global Regulator RpvA Controls Persister Formation and Virulence inStaphylococcus aureus

Han

Liu

et al. 2019

Preprint

Self Cite

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9Staphylococcus aureus is the leading cause of wound and nosocomial infections. 0Persister formation and virulence factors play crucial roles during S. aureus infection. 1However, the mechanisms of persister formation and its relationship to virulence in S.3 2 aureus are poorly understood. In this study, we screened a transposon mutant library 3 3 and identified a LysR-type global transcriptional regulator NWMN_0037, which we 3 4 called RpvA, for regulator of persistence and virulence, whose mutation leads to 3 5 higher susceptibility to antibiotics ampicillin and norfloxacin and various stresses 3 6including oxidative stress, heat, and starvation in late exponential and early stationary 3 7 phase. Interestingly, the rpvA mutant was highly attenuated for virulence compared 3 8with the parent S. aureus Newman strain as shown by a much higher lethal dose, 3 9 reduced ability to survive in macrophages and to form abscess in the mouse model. 4 0 Transcriptional profiling and metabolomic analysis revealed that RpvA could repress 4 1 multiple genes including gapR, gapA, tpi, pgm, eno, glpD, and acs expression and 4 2 enhance production of numerous intermediate metabolites including 4 3 dihydroxyacetone phosphate, 2-phosphoglycerate, acetyl-CoA, glycerol 3-phosphate, 4 4 L-glutamate in the cells. The differentially expressed genes and altered production of 4 5 metabolites are distributed in global metabolism including carbohydrate metabolism, 4 6 amino acid metabolism, energy metabolism and metabolism of cofactors and vitamins. 4 7These metabolic adjustments could cause the cell to go into dormancy, thus promoting 4 8 S. aureus to convert to persisters. In addition, RpvA could upregulate the expression 4 9 of virulence genes including hla, hlgA, hlgB, hlgC, lukF, lukS, lukD, sea and coa, and 5 0

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Absence of Protoheme IX Farnesyltransferase CtaB Causes Virulence Attenuation but Enhances Pigment Production and Persister Survival in MRSA

Cited by 19 publications

References 63 publications

Influence of IS 256 on Genome Variability and Formation of Small-Colony Variants in Staphylococcus aureus

Influence of IS 256 on Genome Variability and Formation of Small-Colony Variants in Staphylococcus aureus

The bacteriostatic effect and mechanism of berberine on Methicillin resistant Staphylococcus aureus in vitro

A Novel LysR-Type Global Regulator RpvA Controls Persister Formation and Virulence inStaphylococcus aureus

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