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

2020 ◽  
Author(s):  
Lei Wang ◽  
Fangfang Zhou ◽  
Minyi Xu ◽  
Pei Lu ◽  
Ming Lin ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Rna Sequencing ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Differentially Expressed ◽  
Control Group ◽  
High Concentration ◽  
Bacteriostatic Effect ◽  
Low Concentration ◽  
Cell Wall Hydrolysis

Abstract 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. 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 MRSA. After co-culturing MRSA with BBR at 512 µg/mL, 64 µg/mL and 8 µg/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 µg/mL; 1/8 MIC) caused no significant damage to MRSA, and the bacterial structure of MRSA remained intact, while high concentration of BBR (512 µg/mL; 8 MIC) 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.

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

2020 ◽  
Author(s):  
Lei Wang ◽  
Fangfang Zhou ◽  
Minyi Xu ◽  
Pei Lu ◽  
Ming Lin ◽  
...  
Keyword(s):  
Cell Wall ◽  
Rna Sequencing ◽  
Differentially Expressed Genes ◽  
Differentially Expressed ◽  
Control Group ◽  
High Concentration ◽  
Bacteriostatic Effect ◽  
Low Concentration ◽  
Transmission Electron ◽  
Cell Wall Hydrolysis

Abstract 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.

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

2019 ◽  
Author(s):  
Lei Wang ◽  
Fangfang Zhou ◽  
Minyi Xu ◽  
Wei Gong ◽  
Shuiying Ji
Keyword(s):  
Cell Wall ◽  
Rna Sequencing ◽  
Differentially Expressed Genes ◽  
Differentially Expressed ◽  
Control Group ◽  
High Concentration ◽  
Bacteriostatic Effect ◽  
Low Concentration ◽  
Kinetics Of

Abstract Background: To observe the bacteriostatic effect of berberine on MRSA, while also exploring the bacteriostatic mechanism of BBR on MRSA. Methods: The MIC of BBR, gentamicin, levofloxacin，amikacin was determined by broth microdilution, while the MICs of BBR combined with gentamicin, levofloxacin，amikacin against MRSA were determined using microdilution checkerboard. Time-killing test were used to determine the kinetics of BBR combined with antibiotics for MRSA. We used conductivity to assess the changes in membrane permeability in response to BBR on MRSA, while also investigating the changes in MRSA morphology by TEM. RNA-sequencing was used to analyze the expression of differentially expressed genes in USA300 after its treatment with BBR. Results: The MICs range of BBR on MRSA was 32-256 µg/mL. The range of FICIs of BBR combined with gentamicin, levofloxacin，amikacin were 0.53-1.06, 0.62-1.5, 0.16-1.25. After co-culturing MRSA with BBR at 512 ug/mL, 64 ug/mL,8 ug/mL, respectively, the conductivity of these group increased by 8.14%,13.08% and 12.01%, respectively. Using TEM, we found that low-concentration of BBR had no significant effect on MRSA structure, medium-concentration of BBR thinned the cell wall of MRSA, while high-concentration of BBR destroyed cell wall, leading to bacterial lysis. RNA-sequencing results showed that there were 754 differentially expressed genes in the high-concentration group compared with the control group, of which 561 genes were up-regulated and 193 genes were down-regulated. Compared with the low-concentration group, there were 590 differentially expressed genes, of which 402 genes were up-regulated and 188 genes were down-regulated. Compared with the control group, 19 genes were differentially expressed in the low-concentration group, of which 11 genes were up-regulated,8 genes were down-regulated. Conclusions: BBR displayed an excellent bacteriostatic effect on MRSA. BBR combined with antibiotics significantly enhanced the bacteriostatic effect on MRSA. BBR inhibited bacteria by destroying the structure of cell wall. RNA-sequencing results demonstrated that the expression of cell wall hydrolysis genes and virulence factor were significantly differentially expressed on MRSA.

Antimicrobial Activity of Galangin and Its Effects on Murein Hydrolases of Vancomycin-Intermediate Staphylococcus aureus (VISA) Strain Mu50

Chemotherapy ◽  
2017 ◽  
Vol 63 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Jing Ouyang ◽  
Fengjun Sun ◽  
Wei Feng ◽  
Yonghong Xie ◽  
Lijuan Ren ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Cell Wall ◽  
Morphological Changes ◽  
Control Group ◽  
Cellular Division ◽  
Murein Hydrolase ◽  
Triton X ◽  
Cell Wall Hydrolysis ◽  
Induced Autolysis

Backgroud: Antibiotic treatment for infections caused by vancomycin-intermediate Staphylococcus aureus (VISA) strains is challenging, and only a few effective and curative methods have been developed to combat these strains. This study aimed to investigate the antimicrobial activity of galangin against S. aureus and its effects on the murein hydrolases of VISA strain Mu50. This is the first report on these effects of galangin, and it may help to improve the treatment for VISA infections by demonstrating the effective use of galangin. Methods: Firstly, the minimum inhibitory concentration (MIC) and growth curve were used to investigate the antimicrobial activity of galangin against S. aureus. Secondly, transmission electron microscopy (TEM) was used to observe morphological changes of VISA strain Mu50. Thirdly, Triton X-100-induced autolysis and cell wall hydrolysis assays were performed to determine the activities of the murein hydrolases of Mu50. Finally, fluorescence real-time quantitative PCR was used to investigate the expression of the murein hydrolase-related Mu50 genes. Results: The results indicated that the MIC of galangin was 32 μg/mL against ATCC25293, N315, and Mu50, and galangin could significantly suppress the bacterial growth (p < 0.05) with concentrations of 4, 8 and 16 μg/mL, compared with control group (0 μg/mL). To explore the possible reasons of bacteriostatic effects of galangin, we observed morphological changes using TEM which showed that the division of Mu50 daughter cells treated with galangin was obviously inhibited. Considering the vital role of murein hydrolases in cellular division, assays were performed, and galangin markedly decreased Triton X-100-induced autolysis and cell wall hydrolysis. Galangin also significantly inhibited the expression of the murein hydrolase genes (atl, lytM, and lytN) and their regulatory genes (cidR, cidA, and cidB). Conclusions: Our findings indicated that galangin can effectively inhibit murein hydrolase activity as well as the growth of VISA strain Mu50.

The Effects of Shock Vancomycin Concentrations on the Formation of Heteroresistance in Staphylococcus aureus

2020 ◽  
Vol 65 (9-10) ◽  
pp. 3-7
Author(s):  
V. V. Gostev ◽  
Yu. V. Sopova ◽  
O. S. Kalinogorskaya ◽  
M. E. Velizhanina ◽  
I. V. Lazareva ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
In Vitro Selection ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
High Concentration ◽  
Short Term ◽  
High Concentrations ◽  
Selection Of ◽  
Selection Of Resistance ◽  
Test Cultures

Glycopeptides are the basis of the treatment of infections caused by MRSA (Methicillin-Resistant Staphylococcus aureus). Previously, it was demonstrated that antibiotic tolerant phenotypes are formed during selection of resistance under the influence of high concentrations of antibiotics. The present study uses a similar in vitro selection model with vancomycin. Clinical isolates of MRSA belonging to genetic lines ST8 and ST239, as well as the MSSA (ATCC29213) strain, were included in the experiment. Test isolates were incubated for five hours in a medium with a high concentration of vancomycin (50 μg/ml). Test cultures were grown on the medium without antibiotic for 18 hours after each exposure. A total of ten exposure cycles were performed. Vancomycin was characterized by bacteriostatic action; the proportion of surviving cells after exposure was 70–100%. After selection, there was a slight increase in the MIC to vancomycin (MIC 2 μg/ml), teicoplanin (MIC 1.5–3 μg/ml) and daptomycin (MIC 0.25–2 μg/ml). According to the results of PAP analysis, all strains showed an increase in the area under curve depending on the concentration of vancomycin after selection, while a heteroresistant phenotype (with PAP/AUC 0.9) was detected in three isolates. All isolates showed walK mutations (T188S, D235N, E261V, V380I, and G223D). Exposure to short-term shock concentrations of vancomycin promotes the formation of heteroresistance in both MRSA and MSSA. Formation of VISA phenotypes is possible during therapy with vancomycin.

scholarly journals Rhodomyrtone Accumulates in Bacterial Cell Wall and Cell Membrane and Inhibits the Synthesis of Multiple Cellular Macromolecules in Epidemic Methicillin-Resistant Staphylococcus aureus

Antibiotics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 543
Author(s):  
Ozioma F. Nwabor ◽  
Sukanlaya Leejae ◽  
Supayang P. Voravuthikunchai
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Cell Membrane ◽  
Bacterial Cell ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Treatment Options ◽  
Bacterial Cell Wall ◽  
Methicillin Resistant ◽  
Gram Positive Bacteria ◽  
Inhibitor Compounds

As the burden of antibacterial resistance worsens and treatment options become narrower, rhodomyrtone—a novel natural antibiotic agent with a new antibacterial mechanism—could replace existing antibiotics for the treatment of infections caused by multi-drug resistant Gram-positive bacteria. In this study, rhodomyrtone was detected within the cell by means of an easy an inexpensive method. The antibacterial effects of rhodomyrtone were investigated on epidemic methicillin-resistant Staphylococcus aureus. Thin-layer chromatography demonstrated the entrapment and accumulation of rhodomyrtone within the bacterial cell wall and cell membrane. The incorporation of radiolabelled precursors revealed that rhodomyrtone inhibited the synthesis of macromolecules including DNA, RNA, proteins, the cell wall, and lipids. Following the treatment with rhodomyrtone at MIC (0.5–1 µg/mL), the synthesis of all macromolecules was significantly inhibited (p ≤ 0.05) after 4 h. Inhibition of macromolecule synthesis was demonstrated after 30 min at a higher concentration of rhodomyrtone (4× MIC), comparable to standard inhibitor compounds. In contrast, rhodomyrtone did not affect lipase activity in staphylococci—both epidemic methicillin-resistant S. aureus and S. aureus ATCC 29213. Interfering with the synthesis of multiple macromolecules is thought to be one of the antibacterial mechanisms of rhodomyrtone.

COMMUNITY ACQUIRED METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS HAND INFECTIONS: A SOUTH PACIFIC PERSPECTIVE — CHARACTERISTICS AND IMPLICATIONS FOR ANTIBIOTIC COVERAGE

Hand Surgery ◽  
2012 ◽  
Vol 17 (03) ◽  
pp. 317-324 ◽  
Author(s):  
Derek Buchanan ◽  
Wolfgang Heiss-Dunlop ◽  
Jon A. Mathy
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Treatment ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
The United States ◽  
Control Group ◽  
Methicillin Resistant ◽  
Empiric Treatment ◽  
Sensitivity Data ◽  
Culture Positive ◽  
Antibiotic Coverage

Purpose: Community acquired methicillin resistant Staphylococcus aureus (CA-MRSA) infections are reported to be increasing worldwide. In the United States when rates exceed 15% empiric treatment is suggested. The aim of our study was to determine local rates and treatment of CA-MRSA within our region. Methods: Nine hundred and forty-two patients were admitted to our service during a six-year period with culture-positive hand infections identified from operative cultures at the time of surgery. Results: Sixty-six (7.0%) patients had CA-MRSA positive cultures identified. Thirty-two (48.5%) patients were noted to have remained on antibiotic treatment that did not reflect their MRSA positive status after cultures returned. Despite this, re-admission and re-operation rates were low and comparable to our non-MRSA control group. Conclusions: Within our CA-MRSA group, current rates do not support automatic empiric treatment for CA-MRSA. Based on sensitivity data, co-trimoxazole and intravenous vancomycin are appropriate and effective antibiotic treatment within our region. Our data supports the importance of drainage of pyogenic infections in helping to resolve complicated hand infections.

scholarly journals Utilizing Pharmacy Records to Assess Antibiotic Prescribing Patterns on the Incidence of Community-Acquired Methicillin-Resistant Staphylococcus aureus Infections in Children

2007 ◽  
Vol 12 (2) ◽  
pp. 91-101
Author(s):  
Peter N. Johnson ◽  
Robert P. Rapp ◽  
Christopher T. Nelson ◽  
J.S. Butler ◽  
Sue Overman ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Therapy ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Prescribing Patterns ◽  
Control Group ◽  
Antibiotic Prescribing ◽  
Antibiotic Exposure ◽  
Pharmacy Records ◽  
Methicillin Resistant ◽  
Prior Antibiotic Therapy

OBJECTIVE To assess the effect of prior antibiotic therapy on the incidence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections in children. METHODS This was a concurrent and retrospective review of antibiotic records for children &lt; 18 years of age with documented CA-MRSA infection identified between January 1, 2004, and December 31, 2005. Antibiotic records were compared against a control group. The primary outcome was the incidence of CA-MRSA using linear regression as a function of age and prior antibiotic therapy (i.e., 3 months prior to admission). Secondary objectives included a comparison of antibiotic courses and classes and a description of antibiotic susceptibilities in patients with CA-MRSA RESULTS Data from 26 patients were included. Nine out of 51 patients (18%) with CA-MRSA were included. Another 17 children were enrolled in the control group. The median age was approximately 1.75 years (0.08–14 years) in the CA-MRSA group versus 2.75 years (0.005-15 years) in the control group. A statistical difference was noted in the number of patients with prior antibiotic exposure between the CA-MRSA and control group, 8 (88.9%) versus 6 (35.3%), respectively (P = .01). Antibiotic exposure was found to be a significant independent risk factor (P = .005; 95% CI, 0.167–0.846) for the development of CA-MRSA. The interaction between antibiotic exposure and age &lt; 3 was the most significant predictor of CA-MRSA (P = .019; 95% CI, 0.139–1.40). CONCLUSIONS Prior antibiotic therapy in patients &lt; 3 years of age was associated with a significant risk of developing CA-MRSA. A comprehensive assessment of CA-MRSA patients should include objective methods of measuring prior antibiotic exposure such as pharmacy records.

scholarly journals Glucanase-Induced Stipe Wall Extension Shows Distinct Differences from Chitinase-Induced Stipe Wall Extension of Coprinopsis cinerea

2019 ◽  
Vol 85 (21) ◽  
Author(s):  
Liqin Kang ◽  
Jiangsheng Zhou ◽  
Rui Wang ◽  
Xingwei Zhang ◽  
Cuicui Liu ◽  
...  
Keyword(s):  
Cell Wall ◽  
Elongation Growth ◽  
Extension Rate ◽  
Coprinopsis Cinerea ◽  
High Concentration ◽  
Content Type ◽  
Low Concentration ◽  
Cell Wall Extension ◽  
Stipe Elongation ◽  
Extension Activity

ABSTRACT This study reports that a high concentration of the endo-β-1,3-glucanase ENG (200 μg ml−1) induced heat-inactivated stipe wall extension of Coprinopsis cinerea, whereas a high concentration of the extracellular β-glucosidase BGL2 (1,000 μg ml−1) did not; however, in combination, low concentrations of ENG (25 μg ml−1) and BGL2 (260 μg ml−1) induced heat-inactivated stipe cell wall extension. In contrast to the previously reported chitinase-reconstituted stipe wall extension, β-1,3-glucanase-reconstituted heat-inactivated stipe cell wall extension initially exhibited a fast extension rate that quickly decreased to zero after approximately 60 min; the stipe cell wall extension induced by a high concentration of β-1,3-glucanase did not result in stipe breakage during measurement, and the inner surfaces of glucanase-reconstituted extended cell walls still remained as amorphous matrices that did not appear to have been damaged. These distinctive features of the β-1,3-glucanase-reconstituted wall extension may be because chitin chains are cross-linked not only to the nonreducing termini of the side chains and the backbones of β-1,6 branched β-1,3-glucans but also to other polysaccharides. Remarkably, a low concentration of either the β-1,3-glucanase ENG or of chitinase ChiE1 did not induce heat-inactivated stipe wall extension, but a combination of these two enzymes, each at a low concentration, showed stipe cell wall extension activity that exhibited a steady and continuous wall extension profile. Therefore, we concluded that the stipe cell wall extension is the result of the synergistic actions of glucanases and chitinases. IMPORTANCE We previously reported that the chitinase could induce stipe wall extension and was involved in stipe elongation growth of the mushroom Coprinopsis cinerea. In this study, we explored that β-1,3-glucanase also induced stipe cell wall extension. Interestingly, the extension profile and extended ultra-architecture of β-1,3-glucanase-reconstituted stipe wall were different from those of chitinase-reconstituted stipe wall. However, β-1,3-glucanase cooperated with chitinase to induce stipe cell wall extension. The significance of this synergy between glucanases and chitinases is that it enables a low concentration of active enzymes to induce wall extension, and the involvement of β-1,3-glucanases is necessary for the cell wall remodeling and the addition of new β-glucans during stipe elongation growth.

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