scholarly journals Antibacterial and Antibiofilm Activity of Mercaptophenol Functionalized-Gold Nanorods Against a Clinical Isolate of Methicillin-Resistant Staphylococcus Aureus

2021 ◽  
Author(s):  
Nahla O. Eltai ◽  
Nouf Mahmoud ◽  
Zain Z. Zakaria ◽  
Hana Abdelrahman ◽  
Ala-Eddin Al Moustafa ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Clinical Isolate ◽  
Gold Nanorods ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Antibiofilm Activity ◽  
Methicillin Resistant ◽  
Vis Spectroscopy ◽  
Sem Imaging ◽  
Surface Modified

Abstract Gold nanorods (AuNRs) were synthesized and surface functionalized with 4-mercaptophenol (4-MPH) ligand. The surface-functionalized AuNRs, 4-MPH-AuNRs, were characterized by UV-Vis spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM) imaging, zeta potential, and Fourier-Transformed Infrared (FTIR) spectroscopy. The antibacterial and antibiofilm activities of 4-MPH-AuNRs were evaluated against a clinical isolate of Methicillin-Resistant Staphylococcus aureus (MRSA). The results indicate that the surface-modified nanorods, 4-MPH-AuNRs, exhibit a bactericidal activity with a minimum inhibitory concentration (MIC) of ~6.25 \(\mu\)g/ml against a planktonic suspension of MRSA. Furthermore, 4-MPH-AuNRs resulted in 2-3 log-cycle reduction of MRSA biofilm viable count over a concentration range of 100-4.0 \(\mu\)g/ml. The bacterial uptake of surface-modified nanorods was investigated by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and scanning electron microscopy (SEM) imaging; the results reveal that ~27% of the nanorods were internalized into the bacterial cells after 6 hrs of exposure. SEM imaging revealed a significant accumulation of the nanorods at the bacterial cell wall and a possible cellular internalization. Thus, 4-MPH-AuNRs can be considered a potential novel antibacterial agent, particularly against resistant MRSA strain biofilm.

Protein expression profiles in methicillin-resistant Staphylococcus aureus (MRSA) under effects of subminimal inhibitory concentrations of imipenem

2019 ◽  
Vol 366 (15) ◽  
Author(s):  
Jichun Wang ◽  
Junrui Wang ◽  
Yanyan Wang ◽  
Peng Sun ◽  
Xiaohui Zou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Cellular Proliferation ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Expression Profiles ◽  
Gram Negative Bacteria ◽  
Beta Lactam ◽  
Gram Negative ◽  
Methicillin Resistant

ABSTRACT Imipenem is a beta-lactam antibiotic mainly active against gram-negative bacterial pathogens and also could cause cell wall impairment in methicillin-resistant Staphylococcus aureus(MRSA). However, related antibacterial mechanisms of imipenem on MRSA and mixed infections of MRSA and gram-negative bacteria are relatively poorly revealed. This study was to identify proteins in the MRSA response to subminimal inhibitory concentrations (sub-MICs) of imipenem treatment. Our results showed that 240 and 58 different expression proteins (DEPs) in sub-MICs imipenem-treated S3 (a standard MRSA strain) and S23 (a clinical MRSA strain) strains were identified through the isobaric tag for relative and absolute quantitation method when compared with untreated S3 and S23 strains, respectively, which was further confirmed by multiple reactions monitoring. Our result also demonstrated that expressions of multiple DEPs involved in cellular proliferation, metabolism and virulence were significantly changed in S3 and S23 strains, which was proved by gene ontology annotations and qPCR analysis. Further, transmission electron microscopy and scanning electron microscopy analysis showed cell wall deficiency, cell lysis and abnormal nuclear mitosis on S23 strain. Our study provides important information for understanding the antibacterial mechanisms of imipenem on MRSA and for better usage of imipenem on patients co-infected with MRSA and other multidrug-resistant gram-negative bacteria.

scholarly journals Fungal Extract of Lasiodiplodia pseudotheobromae IBRL OS-64 Inhibits the Growth of Skin Pathogenic Bacterium and Attenuates Biofilms of Methicillin-Resistant Staphylococcus aureus

2021 ◽  
Vol 28 (4) ◽  
pp. 24-36
Author(s):  
Mohd Taufiq Mat Jalil ◽  
Darah Ibrahim
Keyword(s):  
Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Cell Damage ◽  
Multidrug Resistant ◽  
Industrial Biotechnology ◽  
Bacterial Cells ◽  
Methicillin Resistant ◽  
Fungal Extract

Background: The emergence of multidrug-resistant pathogens associated with biofilm formation can cause life-threatening infections to humans. Therefore, the present study aims to evaluate the effects of the fungal extract of Lasiodiplodia pseudotheobromae (L. pseudotheobromae) Industrial Biotechnology Research Laboratory (IBRL) OS-64 on bacterial cells and the biofilm formation of methicillin-resistant Staphylococcus aureus (MRSA). Methods: Broth microdilution and semi-quantitative adherence assays were conducted to determine the anti-biofilm activity of the fungal extract. Light and scanning electron microscopy (SEM) analyses were performed to observe the effect of the fungal extract on biofilm formation by MRSA. Results: The transmission electron microscopy (TEM) microphotographs showed that the bacterial cells were severely damaged upon 24 h exposure to the extract and displayed several symptoms such as cell shrinkage and breakage. Meanwhile, results from the antibiofilm study indicated the extract attenuated the initial and preformed biofilms of MRSA by 80.82% and 61.39%, respectively. The initial biofilm was more sensitive to the extract compared to the pre-formed biofilm, as evidenced by the light microscopy and SEM observations that demonstrated more severe bacterial cell damage on the initial biofilms compared to pre-formed biofilms. Conclusion: The ethyl acetate extract of L. pseudotheobromae IBRL OS-64 significantly inhibited bacterial cells growth and eliminated biofilm formation by MRSA.

scholarly journals Antimicrobial and Antibiofilm Activities of Essential Oils against Escherichia coli O157:H7 and Methicillin-Resistant Staphylococcus aureus (MRSA)

Antibiotics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 730
Author(s):  
Nicolás Gómez-Sequeda ◽  
Marlon Cáceres ◽  
Elena E. Stashenko ◽  
William Hidalgo ◽  
Claudia Ortiz
Keyword(s):  
Staphylococcus Aureus ◽  
Essential Oils ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Biological Activities ◽  
Antibiofilm Activity ◽  
Methicillin Resistant ◽  
E Coli ◽  
Microbial Infections

The emergence of multidrug resistant microorganisms represents a global challenge due to the lack of new effective antimicrobial agents. In this sense, essential oils (EOs) are an alternative to be considered because of their anti-inflammatory, antiviral, antibacterial, and antibiofilm biological activities. Therefore, multiple efforts have been made to consider the potential use of EOs in the treatment of infections which are caused by resistant microorganisms. In this study, 15 EOs of both Colombian and introduced aromatic plants were evaluated against pathogenic strains of E. coli O157:H7 and methicillin resistant Staphylococcus aureus (MRSA) in planktonic and sessile states in order to identify relevant and promising alternatives for the treatment of microbial infections. Forty different compounds were identified in the 15 EO with nine of them constituted mainly by oxygenated monoterpenes (OM). EOs from Lippia origanoides, chemotypes thymol, and carvacrol, displayed the highest antibacterial activity against E. coli O157:H7 (MIC50 = 0.9 and 0.3 mg/mL, respectively) and MRSA (MIC50 = 1.2 and 0.6 mg/mL, respectively). These compounds from EOs had also the highest antibiofilm activity (inhibition percentage > 70.3%). Using scanning electron microscopy (SEM), changes in the size and morphology of both bacteria were observed when they were exposed to sub-inhibitory concentrations of L. origanoides EO carvacrol chemotype. EOs from L. origanoides, thymol, and carvacrol chemotypes represented a viable alternative for the treatment of microbial infections; however, the Selectivity Index (SI ≤ 3) indicated that it was necessary to study alternatives to reduce its in vitro cytotoxicity.

Bacteriological, Toxicological and Mutagenic Evaluations of the Formulated Ointment of Knobweed (Hyptis capitata Jacq.) Leaf Extract against Methicillin-Resistant Staphylococcus aureus

10.17158/339 ◽  
2014 ◽  
Vol 18 (2) ◽  
Author(s):  
Judee N. Nogodula ◽  
Rose Ann S. Mancenido ◽  
Ivana Lee M. Miranda ◽  
Darlene S. Quiñon
Keyword(s):  
Staphylococcus Aureus ◽  
Clinical Isolate ◽  
Leaf Extract ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Multiple Drug ◽  
Zone Of Inhibition ◽  
Methicillin Resistant ◽  
Multiple Drug Resistant ◽  
Crude Leaf Extract ◽  
Observation Results

<p>The emergence of multiple drug resistant Methicillin-Resistant Staphylococcus aureus (MRSA) has become a global problem. Fortunately, many plants found from Mindanaon lumads have potential curative property for different ailments. Hence, the ethnopharmacologic practice of the knobweed (Hyptis capitata) was scientifically assessed for antibacterial activity, toxicity, mutagenicity and pharmacological screenings of crude leaf extract in formulation of ointment as treatment of MRSA infections. Acute Dermal Toxicity employed female albino rabbits for 14 days. Antibacterial screenings used Kirby Bauer, Minimum Inhibitory Concentration (MIC) and potency tests. Ames test used Salmonella typhimurium TA98. Pharmacological assay was limited to physical characteristics of ointment and sensitivity (patch) test using albino rabbits (24 to 72 hours of observation). Results revealed that leaf extract was not toxic and had promising antibacterial action with 19.22 mm (±0.82) zone of inhibition on MRSA ATCC 43300 and 17.41 mm ±0.77 on clinical isolate. It had similar potency with Vancomycin at 6.54ug. MIC established the reduction of cell viability at 0.0263g/mL without revertant colonies grown; hence, it was not mutagenic. Efficacy of ointment with a hydrophilic base exhibited 16.11 mm (±1.73) zone of inhibition on MRSA ATCC and 16.12 mm (± 2.08) for clinical isolate. Neither erythema nor edema was observed.</p>

scholarly journals Complete Genome Sequence of Staphylococcus aureus Strain JKD6159, a Unique Australian Clone of ST93-IV Community Methicillin-Resistant Staphylococcus aureus

2010 ◽  
Vol 192 (20) ◽  
pp. 5556-5557 ◽  
Author(s):  
Kyra Chua ◽  
Torsten Seemann ◽  
Paul F. Harrison ◽  
John K. Davies ◽  
Scott J. Coutts ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Clinical Isolate ◽  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Skin Infection ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Aureus Strain ◽  
Invasive Infection ◽  
Methicillin Resistant

ABSTRACT Community methicillin-resistant Staphylococcus aureus (cMRSA) is an emerging issue that has resulted in multiple worldwide epidemics. We report the first complete genome sequence of an ST93-MRSA-IV clinical isolate that caused severe invasive infection and a familial outbreak of skin infection. This isolate is a representative of the most common Australian clone of cMRSA that is more distantly related to the previously sequenced genomes of S. aureus.

Antibiofilm activity of Vetiveria zizanioides root extract against methicillin-resistant Staphylococcus aureus

2017 ◽  
Vol 110 ◽  
pp. 313-324 ◽  
Author(s):  
Arunachalam Kannappan ◽  
Shanmugaraj Gowrishankar ◽  
Ramanathan Srinivasan ◽  
Shunmugiah Karutha Pandian ◽  
Arumugam Veera Ravi
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Antibiofilm Activity ◽  
Root Extract ◽  
Vetiveria Zizanioides ◽  
Methicillin Resistant
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