scholarly journals Ocimum gratissimum Capped Sulfur Nanoparticles and Antibacterial Efficacy against Multidrug-Resistant Microbes

2020 ◽  
pp. 85-95
Author(s):  
Owolabi M. Bankole ◽  
Oludare Temitope Osuntokun ◽  
Adedapo Adeola ◽  
Afolabi Owoeye
Keyword(s):  
Staphylococcus Aureus ◽  
Oxalic Acid ◽  
Plant Extract ◽  
Research Work ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Clinical Isolates ◽  
Ocimum Gratissimum ◽  
Salmonella Pullorum ◽  
Sulfur Nanoparticles

This manuscript reports for the first time synthesis of sulfur nanoparticles prepared from thiosulphatepentahydrate ( ) using either oxalic acid alone ( ), or mixture of oxalic acid and aqueous solution of Ocimum gratissimum ( ). The synthesized sulfur nanoparticles were obtained in satisfactory yields, and characterized with techniques such asUV-Vis, XRD, SEM, EDX, TEM, and FT-IR. Presence of capping agents: Oxalic acid and biomolecule contents of Ocimum gratissimum were confirmed by FTIR. Crystallinity, morphology, shapes and elemental compositions of as-prepared nanoparticles were confirmed by XRD, SEM, TEM and EDX, respectively. Antimicrobial activities of the prepared sulfur nanoparticles against five (5) multidrug-resistant microbes were used for this research work. This included Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and Salmonella pullorum. The zone of inhibition of the sulfur nanoparticles tested against selected clinical isolates. Staphylococcus aureus was observed to have the highest susceptibility to sulfur nanoparticles ( ) mediated with Ocimum gratissimum plant extract with diameter of 21.0mm; E.coli and Salmonella P. aeruginosa showed resistance. All tested clinical isolates were resistant to the other sulfur nanoparticles (SNP1) synthesized in the absence of Ocimum gratissimum plant extract.

scholarly journals Comparative Study of Ocimum gratissimum Mediated Nanoparticles and Conventional Antibiotics against Endophytic Leguminous Bacteria and Selected Clinical Isolates

2020 ◽  
pp. 42-59
Author(s):  
Oludare Temitope Osuntokun ◽  
Olayemi Stephen Bakare ◽  
Owolabi Mutolib Bankole ◽  
O. Ajayi Ayodele
Keyword(s):  
Antimicrobial Susceptibility ◽  
Endophytic Bacteria ◽  
Research Work ◽  
Clinical Isolates ◽  
Antimicrobial Susceptibility Test ◽  
Leguminous Plants ◽  
Ocimum Gratissimum ◽  
Zones Of Inhibition ◽  
Conventional Antibiotics ◽  
Sulfur Nanoparticles

The purpose of this research work is to compare the antimicrobial activities of conventional antibiotics and Ocimum gratissimum mediated nanoparticle against microorganisms isolated from endosphere of leguminous plants and selected clinical organisms. The microorganisms are becoming a resistant reservoir to conventional antibiotics, there is a great need, to research into plant mediated nanoparticles, to combat this great menace of resistant organisms, this therefore was the basic hypothesis of this research work. The Endophytic Leguminous plants used for this research work were Mucuna pruriens, Calopogonium mucunoides and Vigna unguiculata. The plants were randomly collected from Federal College of Agriculture, Akure (7.2704° N, 5.2241° E).Endophytic bacteria were isolated, identified and characterized from the endospheres of the leguminous plants using biochemical test, sugar fermentation and Bergey’s manual. The antimicrobial susceptibility test for endophytic isolates and clinical isolates were performed using Kirby-Bauer disc diffusion technique.The same procedure was repeated for the two sulfur nanoparticles The sulfur nanoparticles were synthesized using Sodium thiosulfate pentahydrate, citric acid (C_6 H_8 O_7,AR) with leaf extract of Ocimum gratissimum, SNP1 and SNP2 (Solid reflectance spectrum); SNP1/SNP2 was synthesized in the presence/absence of O. gratissimum and characterized on shimadzu UV-VIS-NIR spectrophotometer UV-3100 with a MPCF-3100 sample compartment. The probable number of organisms isolates from the leguminous plants ranges between 109-1022 cfu and all the endophytic isolates were found to be Gram positive rods. The probable organisms isolated from the leguminoius plants were Microbacterium lacticum, Cellulomonas flavigena and Bacillus spp including;B. pumilus, B. subtilis and B. amylolyticus. Bacillus subtilis. All endophytic bacteria were resistant to antimicrobial susceptibility test using Cephalosporins (oxoid) and multiple susceptibility disc with a diameter between 11mm and 20mm. Endophytic bacteria were susceptible to the SNP1 sulfur nano particles with a diameter between 9mm and 14mm diameter zones of inhibition. The clinical isolates were susceptible to multiple susceptibility disc with of diameter of 11mm and 20mm. Antimicrobial susceptible to SNP1 ranges between  18-20mm zones of inhibition  to SNP2.This study discovered that nanoparticles has better antimicrobial efficacy against both endophytic isolated bacteria and clinical isolates. The present of Ocimum gratissimum drastically increases the efficacy of sulpur mediated nanoparticles. it can be deduced that the Ocimum gratissimum mediated nanoparticle as a potential alternative to antibiotics in this widespread antibiotics resistance era.

scholarly journals Antimicrobial Activities of Ceragenins against Clinical Isolates of Resistant Staphylococcus aureus

2007 ◽  
Vol 51 (4) ◽  
pp. 1268-1273 ◽  
Author(s):  
Judy N. Chin ◽  
Michael J. Rybak ◽  
Chrissy M. Cheung ◽  
Paul B. Savage
Keyword(s):  
Staphylococcus Aureus ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Curve Analysis ◽  
Clinical Isolates ◽  
Resistant Bacteria ◽  
Inoculum Effect ◽  
Kill Curve ◽  
Time Required ◽  
Time Kill

ABSTRACT The rise in the rates of glycopeptide resistance among Staphylococcus aureus isolates is concerning and underscores the need for the development of novel potent compounds. Ceragenins CSA-8 and CSA-13, cationic steroid molecules that mimic endogenous antimicrobial peptides, have previously been demonstrated to possess broad-spectrum activities against multidrug-resistant bacteria. We examined the activities of CSA-8 and CSA-13 against clinical isolates of vancomycin-intermediate S. aureus (VISA), heterogeneous vancomycin-intermediate S. aureus (hVISA), as well as vancomycin-resistant S. aureus (VRSA) and compared them to those of daptomycin, linezolid, and vancomycin by susceptibility testing and killing curve analysis. We also examined CSA-13 for its concentration-dependent activity, inoculum effect, postantibiotic effect (PAE), and synergy in combination with various antimicrobials. Overall, the MICs and minimal bactericidal concentrations of CSA-13 were fourfold lower than those of CSA-8. Time-kill curve analysis of the VRSA, VISA, and hVISA clinical isolates demonstrated concentration-dependent bactericidal killing. An inoculum effect was also observed when a higher starting bacterial density was used, with the time required to achieve 99.9% killing reaching 1 h with a 6-log10-CFU/ml starting inoculum, whereas it was ≥24 h with a 8- to 9-log10-CFU/ml starting inoculum with 10× the MIC (P ≤ 0.001). A concentration-dependent PAE was demonstrated with CSA-13, nearly doubling from 2× to 4× the MIC (P = 0.03). With respect to the CSA-13 antimicrobial combinations, time-kill curve analysis showed no difference in the log10 CFU/ml at 24 h for the majority of the organisms tested. However, early synergy at 4 to 8 h was detected against the VRSA Pennsylvania strain (2002) when CSA-13 was tested in combination with gentamicin, while early additivity was demonstrated against all of the other organisms.

scholarly journals Highlighting the Biotechnological Potential of Deep Oceanic Crust Fungi through the Prism of Their Antimicrobial Activity

Marine Drugs ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. 411
Author(s):  
Maxence Quemener ◽  
Marie Dayras ◽  
Nicolas Frotté ◽  
Stella Debaets ◽  
Christophe Le Meur ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Oceanic Crust ◽  
Gene Clusters ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Antimicrobial Compounds ◽  
Human Pathogens ◽  
Biotechnological Potential ◽  
Fungal Isolates

Among the different tools to address the antibiotic resistance crisis, bioprospecting in complex uncharted habitats to detect novel microorganisms putatively producing original antimicrobial compounds can definitely increase the current therapeutic arsenal of antibiotics. Fungi from numerous habitats have been widely screened for their ability to express specific biosynthetic gene clusters (BGCs) involved in the synthesis of antimicrobial compounds. Here, a collection of unique 75 deep oceanic crust fungi was screened to evaluate their biotechnological potential through the prism of their antimicrobial activity using a polyphasic approach. After a first genetic screening to detect specific BGCs, a second step consisted of an antimicrobial screening that tested the most promising isolates against 11 microbial targets. Here, 12 fungal isolates showed at least one antibacterial and/or antifungal activity (static or lytic) against human pathogens. This analysis also revealed that Staphylococcus aureus ATCC 25923 and Enterococcus faecalis CIP A 186 were the most impacted, followed by Pseudomonas aeruginosa ATCC 27853. A specific focus on three fungal isolates allowed us to detect interesting activity of crude extracts against multidrug-resistant Staphylococcus aureus. Finally, complementary mass spectrometry (MS)-based molecular networking analyses were performed to putatively assign the fungal metabolites and raise hypotheses to link them to the observed antimicrobial activities.

scholarly journals Staphylococcus aureus Infections in Malaysia: A Review of Antimicrobial Resistance and Characteristics of the Clinical Isolates, 1990–2017

Antibiotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 128 ◽  
Author(s):  
Ainal Mardziah Che Hamzah ◽  
Chew Chieng Yeo ◽  
Suat Moi Puah ◽  
Kek Heng Chua ◽  
Ching Hoong Chew
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Sccmec Type ◽  
Epidemiological Data ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Type Iv ◽  
Resistant Strains ◽  
Vancomycin Resistant ◽  
Comprehensive Surveillance

Staphylococcus aureus is an important nosocomial pathogen and its multidrug resistant strains, particularly methicillin-resistant S. aureus (MRSA), poses a serious threat to public health due to its limited therapeutic options. The increasing MRSA resistance towards vancomycin, which is the current drug of last resort, gives a great challenge to the treatment and management of MRSA infections. While vancomycin resistance among Malaysian MRSA isolates has yet to be documented, a case of vancomycin resistant S. aureus has been reported in our neighboring country, Indonesia. In this review, we present the antimicrobial resistance profiles of S. aureus clinical isolates in Malaysia with data obtained from the Malaysian National Surveillance on Antimicrobial Resistance (NSAR) reports as well as various peer-reviewed published records spanning a period of nearly three decades (1990–2017). We also review the clonal types and characteristics of Malaysian S. aureus isolates, where hospital-associated (HA) MRSA isolates tend to carry staphylococcal cassette chromosome mec (SCCmec) type III and were of sequence type (ST)239, whereas community-associated (CA) isolates are mostly SCCmec type IV/V and ST30. More comprehensive surveillance data that include molecular epidemiological data would enable further in-depth understanding of Malaysian S. aureus isolates.

scholarly journals The activity of different extracts from Panax quinquefolium L. cultures against pathogenic Staphylococcus aureus with respect to ginsenoside content

2015 ◽  
Vol 67 (4) ◽  
pp. 1277-1284 ◽  
Author(s):  
Monika Sienkiewicz ◽  
Anna Głowacka ◽  
Edward Kowalczyk ◽  
Ewa Kochan
Keyword(s):  
Staphylococcus Aureus ◽  
Hairy Root ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Hairy Root Cultures ◽  
Root Cultures ◽  
Panax Quinquefolium ◽  
Disk Diffusion Method ◽  
Ginsenoside Content

Ginsenosides can be isolated from various cultures of Panax quinquefolium L., American ginseng. The aim of the study was to determine the antibacterial activity of extracts from leaves, stalks, hairy root cultures and field roots of P. quinquefolium L. containing ginsenosides against Staphylococcus aureus isolates obtained from various clinical materials. The agar well diffusion assay was used to evaluate microbial growth inhibition at various concentrations of extracts. The susceptibility of the clinical isolates to recommended antibiotics was determined with the disk-diffusion method. The results showed that the tested extracts inhibited the growth of all S. aureus clinical isolates, including MRSA (methicillin-resistant S. aureus) with MIC values ranging from 0.5 mg/mL to 1.7 mg/mL. The level of antimicrobial activity of extracts depends on the ginsenoside content. Both field roots and hairy root cultures represent excellent sources of these metabolites. Extracts with ginsenosides were found to inhibit multidrug-resistant staphylococci and can be a valuable complement to antistaphylococcal therapy.

Higher biofilm formation in multidrug-resistant clinical isolates of Staphylococcus aureus

2008 ◽  
Vol 32 (1) ◽  
pp. 68-72 ◽  
Author(s):  
An Sung Kwon ◽  
Gwang Chul Park ◽  
So Yeon Ryu ◽  
Dong Hoon Lim ◽  
Dong Yoon Lim ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Multidrug Resistant ◽  
Clinical Isolates

scholarly journals Promising Antibiofilm Agents: Recent Breakthrough against Biofilm Producing Methicillin-Resistant Staphylococcus aureus

Antibiotics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 667 ◽  
Author(s):  
Marwa I. Abd El-Hamid ◽  
El-sayed Y. El-Naenaeey ◽  
Toka M kandeel ◽  
Wael A. H. Hegazy ◽  
Rasha A. Mosbah ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Proteinase K ◽  
Zno Nps ◽  
Methicillin Resistant ◽  
Biofilm Production ◽  
Antibiofilm Agents

Multidrug resistant (MDR) methicillin-resistant Staphylococcus aureus (MRSA) is a superbug pathogen that causes serious diseases. One of the main reasons for the lack of the effectiveness of antibiotic therapy against infections caused by this resistant pathogen is the recalcitrant nature of MRSA biofilms, which results in an increasingly serious situation worldwide. Consequently, the development of innovative biofilm inhibitors is urgently needed to control the biofilm formation by this pathogen. In this work, we thus sought to evaluate the biofilm inhibiting ability of some promising antibiofilm agents such as zinc oxide nanoparticles (Zno NPs), proteinase K, and hamamelitannin (HAM) in managing the MRSA biofilms. Different phenotypic and genotypic methods were used to identify the biofilm producing MDR MRSA isolates and the antibiofilm/antimicrobial activities of the used promising agents. Our study demonstrated strong antibiofilm activities of ZnO NPs, proteinase K, and HAM against MRSA biofilms along with their transcriptional modulation of biofilm (intercellular adhesion A, icaA) and quorum sensing (QS) (agr) genes. Interestingly, only ZnO NPs showed a powerful antimicrobial activity against this pathogen. Collectively, we observed overall positive correlations between the biofilm production and the antimicrobial resistance/agr genotypes II and IV. Meanwhile, there was no significant correlation between the toxin genes and the biofilm production. The ZnO NPs were recommended to be used alone as potent antimicrobial and antibiofilm agents against MDR MRSA and their biofilm-associated diseases. On the other hand, proteinase-K and HAM can be co-administrated with other antimicrobial agents to manage such types of infections.

scholarly journals The Ancestral N-Terminal Domain of Big Defensins Drives Bacterially Triggered Assembly into Antimicrobial Nanonets

mBio ◽  
2019 ◽  
Vol 10 (5) ◽  
Author(s):  
Karine Loth ◽  
Agnès Vergnes ◽  
Cairé Barreto ◽  
Sébastien N. Voisin ◽  
Hervé Meudal ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Bactericidal Activity ◽  
Multidrug Resistant ◽  
High Salt ◽  
Clinical Isolates ◽  
Host Defense Peptides ◽  
Hydrophobic Domain ◽  
Content Type ◽  
Terminal Domain

ABSTRACT Big defensins, ancestors of β-defensins, are composed of a β-defensin-like C-terminal domain and a globular hydrophobic ancestral N-terminal domain. This unique structure is found in a limited number of phylogenetically distant species, including mollusks, ancestral chelicerates, and early-branching cephalochordates, mostly living in marine environments. One puzzling evolutionary issue concerns the advantage for these species of having maintained a hydrophobic domain lost during evolution toward β-defensins. Using native ligation chemistry, we produced the oyster Crassostrea gigas BigDef1 (Cg-BigDef1) and its separate domains. Cg-BigDef1 showed salt-stable and broad-range bactericidal activity, including against multidrug-resistant human clinical isolates of Staphylococcus aureus. We found that the ancestral N-terminal domain confers salt-stable antimicrobial activity to the β-defensin-like domain, which is otherwise inactive. Moreover, upon contact with bacteria, the N-terminal domain drives Cg-BigDef1 assembly into nanonets that entrap and kill bacteria. We speculate that the hydrophobic N-terminal domain of big defensins has been retained in marine phyla to confer salt-stable interactions with bacterial membranes in environments where electrostatic interactions are impaired. Those remarkable properties open the way to future drug developments when physiological salt concentrations inhibit the antimicrobial activity of vertebrate β-defensins. IMPORTANCE β-Defensins are host defense peptides controlling infections in species ranging from humans to invertebrates. However, the antimicrobial activity of most human β-defensins is impaired at physiological salt concentrations. We explored the properties of big defensins, the β-defensin ancestors, which have been conserved in a number of marine organisms, mainly mollusks. By focusing on a big defensin from oyster (Cg-BigDef1), we showed that the N-terminal domain lost during evolution toward β-defensins confers bactericidal activity to Cg-BigDef1, even at high salt concentrations. Cg-BigDef1 killed multidrug-resistant human clinical isolates of Staphylococcus aureus. Moreover, the ancestral N-terminal domain drove the assembly of the big defensin into nanonets in which bacteria are entrapped and killed. This discovery may explain why the ancestral N-terminal domain has been maintained in diverse marine phyla and creates a new path of discovery to design β-defensin derivatives active at physiological and high salt concentrations.

scholarly journals Targeting Methicillin-Resistant Staphylococcus aureus with Short Salt-Resistant Synthetic Peptides

2014 ◽  
Vol 58 (7) ◽  
pp. 4113-4122 ◽  
Author(s):  
Mohamed F. Mohamed ◽  
Maha I. Hamed ◽  
Alyssa Panitch ◽  
Mohamed N. Seleem
Keyword(s):  
Staphylococcus Aureus ◽  
Synthetic Peptides ◽  
Bactericidal Effect ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Net Charge ◽  
Methicillin Resistant ◽  
Content Type ◽  
C Terminus ◽  
Conventional Antibiotics

ABSTRACTThe seriousness of microbial resistance combined with the lack of new antimicrobials has increased interest in the development of antimicrobial peptides (AMPs) as novel therapeutics. In this study, we evaluated the antimicrobial activities of two short synthetic peptides, namely, RRIKA and RR. These peptides exhibited potent antimicrobial activity againstStaphylococcus aureus, and their antimicrobial effects were significantly enhanced by addition of three amino acids in the C terminus, which consequently increased the amphipathicity, hydrophobicity, and net charge. Moreover, RRIKA and RR demonstrated a significant and rapid bactericidal effect against clinical and drug-resistantStaphylococcusisolates, including methicillin-resistantStaphylococcus aureus(MRSA), vancomycin-intermediateS. aureus(VISA), vancomycin-resistantS. aureus(VRSA), linezolid-resistantS. aureus, and methicillin-resistantStaphylococcus epidermidis. In contrast to many natural AMPs, RRIKA and RR retained their activity in the presence of physiological concentrations of NaCl and MgCl2. Both RRIKA and RR enhanced the killing of lysostaphin more than 1,000-fold and eradicated MRSA and VRSA isolates within 20 min. Furthermore, the peptides presented were superior in reducing adherent biofilms ofS. aureusandS. epidermidiscompared to results with conventional antibiotics. Our findings indicate that the staphylocidal effects of our peptides were through permeabilization of the bacterial membrane, leading to leakage of cytoplasmic contents and cell death. Furthermore, peptides were not toxic to HeLa cells at 4- to 8-fold their antimicrobial concentrations. The potent and salt-insensitive antimicrobial activities of these peptides present an attractive therapeutic candidate for treatment of multidrug-resistantS. aureusinfections.

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