Study on Demethoxycurcumin as a promising approach to reverse methicillin-resistance of Staphylococcus aureus

Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA) has always been a thorny pathogen, posing serious threat to public health. Current treatment resort for MRSA infections is still scarce. Research on phytochemical component that can replace antibiotics with limited efficacy may be an innovative method to solve intractable MRSA infections. The present study was devoted to investigating the antibacterial activity of the natural compound demethoxycurcumin (DMC) against MRSA and exploring its possible mechanism for eliminating MRSA resistance. Methods The present study determined minimum inhibitory concentrations (MICs) of DMC, oxacillin, ampicillin and gentamicin against MRSA strains by the broth microdilution method. The synergistic effects of DMC and antibiotics were investigated by the checkerboard method and the time-kill assay. The membrane-permeabilizing agents and ATP synthase inhibitors were employed to explore their impact on the antibacterial ability of DMC. Western blot analysis and qRT-PCR were performed to detect the proteins and genes related to drug resistance and S. aureus exotoxins. Results The MIC of DMC against MRSA is 62.5 µg/ml by broth microdilution method. The synergy between DMC and gentamicin was confirmed by checkerboard method and time-kill assay. When ATP synthase inhibitors blocked the metabolic ability of bacteria, the antibacterial effect of DMC was enhanced. The production of penicillin-binding protein 2a (PBP2a) protein and related genes were reduced by DMC at sub-inhibitory concentrations. In addition, DMC hindered the translation of staphylococcal enterotoxin and the transcription of related gene. Conclusions Based on our results, DMC has a significant inhibitory effect on the vitality of MRSA, and it can be inferred that the mechanism by which DMC reverses MRSA resistance is related to the ability of DMC to block resistance determinants (PBP2a and β-lactamase) and S. aureus exotoxin. This study provides experimental evidences that DMC has the potential to be a candidate substance for the treatment of MRSA infections.

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Study on Demethoxycurcumin as a Promising Approach to Reverse Methicillin-Resistance of Staphylococcus aureus

International Journal of Molecular Sciences ◽

10.3390/ijms22073778 ◽

2021 ◽

Vol 22 (7) ◽

pp. 3778

Author(s):

Qian-Qian Li ◽

Ok-Hwa Kang ◽

Dong-Yeul Kwon

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistant Staphylococcus Aureus ◽

Methicillin Resistance ◽

Synergistic Effects ◽

Penicillin Binding Protein ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Mrsa Strains ◽

Phytochemical Components ◽

Time Kill

Methicillin-resistant Staphylococcus aureus (MRSA) has always been a threatening pathogen. Research on phytochemical components that can replace antibiotics with limited efficacy may be an innovative method to solve intractable MRSA infections. The present study was devoted to investigate the antibacterial activity of the natural compound demethoxycurcumin (DMC) against MRSA and explore its possible mechanism for eliminating MRSA. The minimum inhibitory concentrations (MICs) of DMC against MRSA strains was determined by the broth microdilution method, and the results showed that the MIC of DMC was 62.5 μg/mL. The synergistic effects of DMC and antibiotics were investigated by the checkerboard method and the time–kill assay. The ATP synthase inhibitors were employed to block the metabolic ability of bacteria to explore their synergistic effect on the antibacterial ability of DMC. In addition, western blot analysis and qRT-PCR were performed to detect the proteins and genes related to drug resistance and S. aureus exotoxins. As results, DMC hindered the translation of penicillin-binding protein 2a (PBP2a) and staphylococcal enterotoxin and reduced the transcription of related genes. This study provides experimental evidences that DMC has the potential to be a candidate substance for the treatment of MRSA infections.

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Combination Therapy of Sophoraflavanone B against MRSA:In VitroSynergy Testing

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2013/823794 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 8

Author(s):

Su-Hyun Mun ◽

Ok-Hwa Kang ◽

Dae-Ki Joung ◽

Sung-Bae Kim ◽

Yun-Soo Seo ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Activity ◽

Antibacterial Activity ◽

Multidrug Resistant ◽

Antibacterial Drug ◽

Broth Microdilution ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Kill Curve ◽

Time Kill

Sophoraflavanone B (SPF-B), a known prenylated flavonoid, was isolated from the roots ofDesmodium caudatum. The aim of this study was to determine the antimicrobial synergism of SPF-B combined with antibiotics against methicillin-resistantStaphylococcus aureus(MRSA). MRSA, a multidrug-resistant pathogen, causes both hospital- and community-acquired infections worldwide. The antimicrobial activity of SPF-B was assessed by the broth microdilution method, checkerboard dilution test, and time-kill curve assay. The MIC of SPF-B for 7 strains ofS. aureusranges from 15.6 to 31.25 μg/mL determined. In the checkerboard method, the combinations of SPF-B with antibiotics had a synergistic effect; SPF-B markedly reduced the MICs of theβ-lactam antibiotics: ampicillin (AMP) and oxacillin (OXI); aminoglycosides gentamicin (GET); quinolones ciprofloxacin (CIP) and norfloxacin (NOR) against MRSA. The time-kill curves assay showed that a combined SPF-B and selected antibiotics treatment reduced the bacterial counts below the lowest detectable limit after 24 h. These data suggest that the antibacterial activity of SPF-B against MRSA can be effectively increased through its combination with three groups of antibiotics (β-lactams, aminoglycosides, and quinolones). Our research can be a valuable and significant source for the development of a new antibacterial drug with low MRSA resistance.

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8-hydroxyquinoline-5-(N-4-chlorophenyl) sulfonamide and fluconazole combination as a preventive strategy for Candida biofilm in haemodialysis devices

Journal of Medical Microbiology ◽

10.1099/jmm.0.001377 ◽

2021 ◽

Vol 70 (7) ◽

Author(s):

Letícia Fernandes da Rocha ◽

Bruna Pippi ◽

Angélica Rocha Joaquim ◽

Saulo Fernandes de Andrade ◽

Alexandre Meneghello Fuentefria

Keyword(s):

Biofilm Formation ◽

Synergistic Effects ◽

Local Treatment ◽

The Other ◽

Antibiofilm Activity ◽

Preventive Strategy ◽

Clinical Issue ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Time Kill

Introduction. The presence of Candida biofilms in medical devices is a concerning and important clinical issue for haemodialysis patients who require constant use of prosthetic fistulae and catheters. Hypothesis/Gap Statement. This prolonged use increases the risk of candidaemia due to biofilm formation. PH151 and clioquinol are 8-hydroxyquinoline derivatives that have been studied by our group and showed interesting anti-Candida activity. Aim. This study evaluated the biofilm formation capacity of Candida species on polytetrafluoroethylene (PTFE) and polyurethane (PUR) and investigated the synergistic effects between the compounds PH151 and clioquinol and fluconazole, amphotericin B and caspofungin against biofilm cells removed from those materials. Further, the synergistic combination was evaluated in terms of preventing biofilm formation on PTFE and PUR discs. Methodology. Susceptibility testing was performed for planktonic and biofilm cells using the broth microdilution method. The checkerboard method and the time–kill assay were used to evaluate the interactions between antifungal agents. Antibiofilm activity on PTFE and PUR materials was assessed to quantify the prevention of biofilm formation. Results. Candida albicans, Candida glabrata and Candida tropicalis showed ability to form biofilms on both materials. By contrast, Candida parapsilosis did not demonstrate this ability. Synergistic interaction was observed when PH151 was combined with fluconazole in 77.8 % of isolates and this treatment was shown to be concentration- and time-dependent. On the other hand, indifferent interactions were predominantly observed with the other combinations. A reduction in biofilm formation on PUR material of more than 50 % was observed when using PH151 combined with fluconazole. Conclusion. PH151 demonstrated potential as a local treatment for use in a combination therapy approach against Candida biofilm formation on haemodialysis devices.

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In VitroAntistaphylococcal Effects ofEmbelia schimperiExtracts and Their Component Embelin with Oxacillin and Tetracycline

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2015/175983 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 4

Author(s):

Johana Rondevaldova ◽

Olga Leuner ◽

Alemtshay Teka ◽

Ermias Lulekal ◽

Jaroslav Havlik ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Medicinal Plants ◽

Bacterial Infections ◽

Inhibitory Concentration ◽

Developed Countries ◽

Positive Interactions ◽

Fractional Inhibitory Concentration ◽

Broth Microdilution ◽

Microdilution Method ◽

Broth Microdilution Method

Bacterial infections are in less-developed countries traditionally treated by remedies prepared from medicinal plants.Embelia schimperi(Vatke) is a plant used as a taenicide or disinfectant in Ethiopia, very often taken mixed with another plant species. In the present study, we examined two extracts prepared from seeds and twigs with leaves ofE. schimperiand its main present secondary metabolite embelin for their antibacterial combinatory effect with oxacillin and tetracycline against sensitive and resistantStaphylococcus aureusstrains. Minimum inhibitory concentrations were determined through the broth microdilution method, whereas the combinatory effect was evaluated through fractional inhibitory concentration sum (ΣFIC) indices. Results show many positive interactions and synergy occurring in embelin and oxacillin combinations against 4 out of 9 strains (ΣFIC 0.203–0.477) and for embelin and tetracycline combination against 3 out of 9 strains (ΣFIC 0.400–0.496). Moreover, the resistance to oxacillin has been overcome in 2 strains and to tetracycline in 3 strains. According to our knowledge, this is the first study showing antimicrobial combinatory effect ofE. schimperias well as of embelin. These findings can be used for the further research targeted on the development of new antistaphylococcal agents.

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Antibacterial Triterpenoids from the Bark of Sonneratia alba (Lythraceae)

Natural Product Communications ◽

10.1177/1934578x1501000215 ◽

2015 ◽

Vol 10 (2) ◽

pp. 1934578X1501000

Author(s):

Harizon ◽

Betry Pujiastuti ◽

Dikdik Kurnia ◽

Dadan Sumiarsa ◽

Yoshihito Shiono ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antibacterial Activity ◽

Mass Spectrometric ◽

Broth Microdilution ◽

Mass Spectrometric Data ◽

Spectrometric Data ◽

Gram Positive Bacteria ◽

Microdilution Method ◽

Sonneratia Alba ◽

Broth Microdilution Method

The new lupane-type triterpenoid, 3β-hydroxy-lup-9(11), 12-diene, 28-oic acid (1), along with two known lupane-type triterpenoids, lupeol (2) and lupan-3p-ol (3), were isolated from the bark of Sonnetaria alba. The structure of the new compound was elucidated on the basis of spectroscopic and mass spectrometric data analysis. Using the broth microdilution method, all compounds exhibited antibacterial activity against the Gram-positive bacteria Staphylococcus aureus ATCC 6538 and Streptococcus mutans ATCC 25175, with minimum inhibitory concentrations ranging from 15-33 to 35-55 ng/mL, respectively.

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Nosocomial methicillin-resistant Staphylococcus aureus (MRSA) bacteremia in Taiwan: Mortality analyses and the impact of vancomycin, MIC = 2 mg/L, by the broth microdilution method

BMC Infectious Diseases ◽

10.1186/1471-2334-10-159 ◽

2010 ◽

Vol 10 (1) ◽

Cited By ~ 50

Author(s):

Jiun-Ling Wang ◽

Jann-Tay Wang ◽

Wang-Huei Sheng ◽

Yee-Chun Chen ◽

Shan-Chwen Chang

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistant Staphylococcus Aureus ◽

Broth Microdilution ◽

Methicillin Resistant ◽

Microdilution Method ◽

Broth Microdilution Method ◽

The Impact

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Anti Bacterial Activity of Lavandula Extracts, Pathogen and Probiotics Bacteria

10.21203/rs.3.rs-709254/v1 ◽

2021 ◽

Author(s):

Asal khodagholi ◽

Mahdieh Soltani ◽

Mohammad Mehdi Akbarin ◽

Zahra Farjami

Keyword(s):

Food Industry ◽

Herbal Product ◽

Inhibitory Effect ◽

Bacterial Activity ◽

Broth Microdilution ◽

Time Consumption ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Long Time ◽

Bacterial Effect

Abstract Introduction: Herbs of the lavender genus are widely used today as anti-bacterial drugs in traditional medicine. Lavandula angustifolia (LA) is endemic in the Iberian Peninsula and common in Iran that belongs to the Lamiaceae family. Lavandula oils, well known for their scent and aroma, have been used in the perfumery and food industry for many years, therefore the aim of this study is the assessment of the anti-bacterial effect of LA extracts against pathogens and non-pathogen bacteria. Methods: 96-well microplates MICs were determined by the broth microdilution method. Five Serial dilutions from 50 to 1 μg/mL concentrations were admitted for all bacteria which include: Escherichia Coli ATCC 25922, Enterococcus faecalis ATCC 29212, Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 25923, and Probiotics complex. Results: LA watery extract demonstrate the statically inhibitory effect in just 50 g/L concentration against E.Coli, E. Faecalis, Pu, and Probiotic p= 0.024, 0.025, 0.004, and 0.012 respectively, whereas this concentration was 1g/L for Staph. aureus p=0.026. LA alcohol extracts display the same effect in 1g/L for all bacteria p= 0.000.Conclusion: Our results showed that LA in both watery and Alcohol extractions can inhibit both pathogenic and non-pathogen bacteria whereas active compounds are alcohol soluble. Long-time consumption of LA in the herbal product could disrupt normal bacteria of the gastrointestinal system.

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Development, optimization, standardization, and validation of a simple in-house agar gradient method to determine minimum inhibitory concentration of vancomycin for Staphylococcus aureus

Journal of Laboratory Physicians ◽

10.4103/jlp.jlp_11_19 ◽

2019 ◽

Vol 11 (03) ◽

pp. 220-228

Author(s):

Sumit Rai ◽

Mukta Tandon ◽

Narendra Pal Singh ◽

Vikas Manchanda ◽

Iqbal Rajinder Kaur

Keyword(s):

Staphylococcus Aureus ◽

Gradient Method ◽

Inhibitory Concentration ◽

Control Strain ◽

Broth Microdilution ◽

Clinical Strains ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Commercial Strip ◽

Validation Stage

Abstract BACKGROUND: The Clinical and Laboratory Standards Institute recommends reporting minimum inhibitory concentration (MIC) values of vancomycin for Staphylococcus aureus. Commercial MIC strips are expensive, and the traditional broth microdilution method is cumbersome. With this background, we attempted to develop and standardize an in-house agar gradient method to determine MIC values of vancomycin for S. aureus. OBJECTIVES: To develop and validate an in-house vancomycin MIC strip, based on simple agar gradient method for S. aureus as per bioassay development guidelines. MATERIALS AND METHODS: Filter paper gradient strips were made in house and impregnated with varying concentrations of vancomycin to create an antibiotic gradient. During standardization, MICs of ninety clinical strains of S. aureus and ATCC 29213 were tested by the broth microdilution and commercial strip followed by the in-house strip. During the validation stage, MICs of ninety different clinical strains of S. aureus and ATCC 29213 were determined by the in-house strip followed by MIC detection by broth microdilution and commercial strips. A reading of more than ± 1log2 dilution compared with broth microdilution was considered as an outlier. RESULTS: During the initial stage, there were 7/90 outliers in the clinical strains, and no outliers were seen with the ATCC 29213 control strain. Corrective action included increasing precaution during the antibiotic impregnation on the strip. During validation stage, only 4/90 outliers were observed in the clinical strains. The commercial strips had 29/90 among clinical and 15/30 outliers in the control strain during the prevalidation phase. Despite maintaining cold chain during the validation phase, the outliers for commercial strip were 18/90 and 4/30 for clinical and control strains, respectively. CONCLUSION: Reporting vancomycin MIC for S. aureus may be attempted using the in-house method after validating it with a gold standard broth microdilution method and quality control as per protocol.

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