A New Nano-Platform of Erythromycin Combined with Ag Nano-Particle ZnO Nano-Structure against Methicillin-Resistant Staphylococcus aureus

Nano-particles have been combined with antibiotics in recent studies to overcome multidrug-resistant bacteria. Here, we synthesized a nano-material in which Ag nano-particles were assembled with a ZnO nano-structure to form an Ag-ZnO (AZO) nano-composite at low temperature. This material was combined with erythromycin (Ery), an antibiotic effective towards gram-positive bacteria, using three different approaches (AZO + Ery (AZE) [centrifuged (AZE1), used separately after 1-h gap (AZE2), without centrifugation (AZE3)]) to prepare a nano-antibiotic against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). X-ray diffraction analysis and transmission electron microscopy confirmed the presence of Ag nano-particles and ZnO nano-structure. The elemental and chemical state of the elements present in the AZO nano-composite were assessed by X-ray photoelectron spectroscopy. The antibacterial activity of AZE samples against both Escherichia coli and S. aureus strains including MRSA was evaluated in antibacterial and morphological analyses. The AZE3 sample showed greater antibacterial activity than the other samples and was comparable to erythromycin. AZE3 was ~20-fold less prone to developing bacterial resistance following multiple exposures to bacteria compared to erythromycin alone. The AZE3 nano-composite showed good biocompatibility with 293 human embryonic kidney cells. Our newly synthesized nano-platform antibiotics may be useful against multidrug-resistant gram-positive bacteria.

Download Full-text

Antimicrobial activity of Rhipsalis baccifera and Drymoglossum piloselloides against Methicillin Resistant Staphylococcus Aureus and Drug Resistant Acinetobacter baumanii.

International Journal of KIU ◽

10.37966/ijkiu2021021011 ◽

2021 ◽

pp. 32-40

Author(s):

S. D. Kugaperumal ◽

R. D. De Silva ◽

T. D. Karunarathne ◽

C. P. Gunasekara ◽

D. N. A. W. Samarakoon

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Activity ◽

Antibacterial Activity ◽

Methicillin Resistant Staphylococcus Aureus ◽

Chronic Wounds ◽

Multidrug Resistant ◽

Antibiotic Activity ◽

Diffusion Method ◽

Acinetobacter Baumanii ◽

Methicillin Resistant

Methicillin Resistant Staphylococcus aureus (MRSA) and multidrug-resistant Acinetobacter baumanii are known to cause delayed healing of infections in both acute and chronic wounds. Plants are a natural source of novel antimicrobials and many new drugs are derived from plants, as plants contain phytochemicals that have antimicrobial activity. Sri Lanka is a tropical country with a wide variety of plant species, many of which were identified as possessing medicinal qualities and have been used by traditional medicinal practitioners in the treatment of various diseases and ailments. Dressings made of Rhipsalis baccifera and Drymoglossum piloselloides have been used to treat wounds by Sri Lankan traditional medicine practitioners. This study determined the antibacterial activity of aqueous and methanol extracts of R. baccifera and D. piloselloides against MRSA and Multidrug-resistant A. baumanii. Aqueous and methanolic extractions of both plants were done by maceration. Their antibacterial properties were checked against MRSA and A. baumanii by the well diffusion method. The effectiveness of the extract was further tested against factors like temperature and storage time. R. baccifera (aqueous extract) exhibited antimicrobial properties against MRSA but no activity against A. baumanii. The antibiotic activity against MRSA was increased after two months of storage at 4°C. D. piloselloides exhibited no antibiotic activity against both MRSA and A. baumanii. The methanolic extracts did not demonstrate any antibacterial activity.

Download Full-text

EVALUATION OF ANTIBACTERIAL ACTIVITY OF SILVER NANOPARTICLES AGAINST METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS AND DETECTION OF VIRULENCE FACTORS - NUCLEASE, PHOSPHATASE, AND BIO FILM PRODUCTION

Asian Journal of Pharmaceutical and Clinical Research ◽

10.22159/ajpcr.2018.v11i5.24097 ◽

2018 ◽

Vol 11 (5) ◽

pp. 224 ◽

Cited By ~ 1

Author(s):

Manipriya B ◽

Tasneem Banu ◽

Prem Kumar L ◽

Kalyani M

Keyword(s):

Staphylococcus Aureus ◽

Silver Nanoparticles ◽

Antibacterial Activity ◽

Virulence Factors ◽

Bactericidal Activity ◽

Methicillin Resistant Staphylococcus Aureus ◽

Nano Particles ◽

Clinical Isolates ◽

Ag Nps ◽

Methicillin Resistant

Objective: To determine the virulence factors-biofilm, nuclease and phosphatase production in Staphylococcus aureus isolates. To determine the effect of silver nano particles and antibiotics on MRSA by MIC determination and kirby baeur method respectively and finally to compare antibacterial activity of silver nano particles and antibiotics.Methods: In the present study, we explore the antibacterial activity of silver nanoparticles (Ag-NPs) dispersion (10 nm) against reference strain and clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). We evaluated the antibacterial activity of Ag-NPs against MRSA isolated from patients in Saveetha Medical College and Hospital, a tertiary care centre in Chennai, Tamil Nadu. The bactericidal activity of different concentrations of Ag-NPs (200, 100, 50, 25, 12.5, 6.25, 3.125, and 1.5625 μg/ml) was tested by determining MIC using microbroth dilution and MBC by agar dilution methods.. In addition, the virulence factors phosphatase, nuclease, and biofilm production were tested.Result: The values of minimal inhibitory concentration and minimal bactericidal concentration of Ag-NPs against all clinical isolates of MRSA and a single of S. aureus were found in the range of 12.5–50 μg/ml and 12.5–25 μg/ml, respectively, indicating very good bactericidal activity. Ag-NPs with the highest concentration showed almost no growth for up to 16 h representing a bactericidal effect at this concentration. Effect was proportional to dose since 50.0 μg/ml was the most effective dose since the bacterial population did not recover and 12.5 μg/ml was the least effective. All the MRSA isolates were positive for the virulence factors.Conclusion: The study result suggests that Ag-NPs could be used as an effective alternative antibacterial agent.

Download Full-text

Cysteines and Disulfide-Bridged Macrocyclic Mimics of Teixobactin Analogues and Their Antibacterial Activity Evaluation against Methicillin-Resistant Staphylococcus Aureus (MRSA)

Pharmaceutics ◽

10.3390/pharmaceutics10040183 ◽

2018 ◽

Vol 10 (4) ◽

pp. 183 ◽

Cited By ~ 7

Author(s):

Ruba Malkawi ◽

Abhishek Iyer ◽

Anish Parmar ◽

Daniel Lloyd ◽

Eunice Leng Goh ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antibacterial Activity ◽

Methicillin Resistant Staphylococcus Aureus ◽

Building Blocks ◽

Disulfide Bridge ◽

Methicillin Resistant ◽

Macrocyclic Ring ◽

Gram Positive Bacteria ◽

Ester Linkage ◽

First Time

Teixobactin is a highly potent cyclic depsipeptide which kills a broad range of multi-drug resistant, Gram-positive bacteria, such as Methicillin-resistant Staphylococcus aureus (MRSA) without detectable resistance. In this work, we describe the design and rapid synthesis of novel teixobactin analogues containing two cysteine moieties, and the corresponding disulfide-bridged cyclic analogues. These analogues differ from previously reported analogues, such as an Arg10-teixobactin, in terms of their macrocyclic ring size, and feature a disulfide bridge instead of an ester linkage. The new teixobactin analogues were screened against Methicillin-resistant Staphylococcus aureus and Methicillin-sensitive Staphylococcus aureus. Interestingly, one teixobactin analogue containing all l-amino acid building blocks showed antibacterial activity against MRSA for the first time. Our data indicates that macrocyclisation of teixobactin analogues with disulfide bridging is important for improved antibacterial activity. In our work, we have demonstrated the unprecedented use of a disulfide bridge in constructing the macrocyclic ring of teixobactin analogues.

Download Full-text

Antibacterial activity of unifloral honeys against clinical isolates of methicillin-resistant Staphylococcus aureus

Planta Medica ◽

10.1055/s-0029-1234974 ◽

2009 ◽

Vol 75 (09) ◽

Author(s):

A Hannan ◽

MB Hussain ◽

M Absar

Keyword(s):

Staphylococcus Aureus ◽

Antibacterial Activity ◽

Methicillin Resistant Staphylococcus Aureus ◽

Clinical Isolates ◽

Methicillin Resistant

Download Full-text

In vitro antibacterial activity of some spice extracts against methicillin-resistant Staphylococcus aureus isolated from nose of food handlers

International Journal of Pharmaceutical Research ◽

10.31838/ijpr/2020.12.03.412 ◽

2020 ◽

Vol 12 (03) ◽

Keyword(s):

Staphylococcus Aureus ◽

Antibacterial Activity ◽

Methicillin Resistant Staphylococcus Aureus ◽

Food Handlers ◽

Methicillin Resistant ◽

In Vitro Antibacterial Activity

Download Full-text

Faculty Opinions recommendation of Emergence of multidrug-resistant, community-associated, methicillin-resistant Staphylococcus aureus clone USA300 in men who have sex with men.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1102146.558131 ◽

2008 ◽

Author(s):

J Michael Kilby

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistant Staphylococcus Aureus ◽

Multidrug Resistant ◽

Methicillin Resistant ◽

Sex With Men

Download Full-text

The Prevalence of Virulence Determinants and Antibiotic Resistance Patterns in Methicillin—Resistant Staphylococcus aureus in a Nursing Home in Poland

Pathogens ◽

10.3390/pathogens10040427 ◽

2021 ◽

Vol 10 (4) ◽

pp. 427

Author(s):

Martyna Kasela ◽

Agnieszka Grzegorczyk ◽

Bożena Nowakowicz-Dębek ◽

Anna Malm

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistant Staphylococcus Aureus ◽

Variable Number Tandem Repeat ◽

Multidrug Resistant ◽

Variable Number ◽

Pulse Field ◽

Virulence Determinants ◽

Gene Encoding ◽

Methicillin Resistant ◽

Pulse Field Gel Electrophoresis

Nursing homes (NH) contribute to the regional spread of methicillin-resistant Staphylococcus aureus (MRSA). Moreover, residents are vulnerable to the colonization and subsequent infection of MRSA etiology. We aimed at investigating the molecular and phenotypic characteristics of 21 MRSA collected from the residents and personnel in an NH (Lublin, Poland) during 2018. All MRSA were screened for 20 genes encoding virulence determinants (sea-see, eta, etb, tst, lukS-F-PV, eno, cna, ebpS, fib, bbp, fnbA, fnbB, icaADBC) and for resistance to 18 antimicrobials. To establish the relatedness and clonal complexes of MRSA in NH we applied multiple-locus variable-number tandem-repeat fingerprinting (MLVF), pulse field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. We identified four sequence types (ST) among two clonal complexes (CC): ST (CC22) known as EMRSA-15 as well as three novel STs—ST6295 (CC8), ST6293 (CC8) and ST6294. All tested MRSA were negative for sec, eta, etb, lukS-F-PV, bbp and ebpS genes. The most prevalent gene encoding toxin was sed (52.4%; n = 11/21), and adhesins were eno and fnbA (100%). Only 9.5% (n = 2/21) of MRSA were classified as multidrug-resistant. The emergence of novel MRSA with a unique virulence and the presence of epidemic clone EMRSA-15 creates challenges for controlling the spread of MRSA in NH.

Download Full-text

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

Antibiotics ◽

10.3390/antibiotics10050543 ◽

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.

Download Full-text