scholarly journals ANTIMICROBIAL ACTIVITY OF MORINGA OLEIFERA AGAINST MULTIDRUG-RESISTANT STAPHYLOCOCCUS AUREUS ISOLATED FROM RAW MILK

2019 ◽  
Vol 17 (1) ◽  
pp. 587-599 ◽  
Author(s):  
D TIRADO-TORRES ◽  
C A CHAN-KEB ◽  
R A PÉREZ-BALÁN ◽  
B AKE-CANCHÉ ◽  
M I GÓMEZ-SOLANO ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Moringa Oleifera ◽  
Raw Milk ◽  
Multidrug Resistant

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 In Vitro Bactericidal Activity of Human β-Defensin 3 against Multidrug-Resistant Nosocomial Strains

2006 ◽  
Vol 50 (2) ◽  
pp. 806-809 ◽  
Author(s):  
Giuseppantonio Maisetta ◽  
Giovanna Batoni ◽  
Semih Esin ◽  
Walter Florio ◽  
Daria Bottai ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Bactericidal Activity ◽  
Stenotrophomonas Maltophilia ◽  
Bactericidal Effect ◽  
Multidrug Resistant ◽  
Bacterial Strains ◽  
Gram Negative

ABSTRACT The antimicrobial activity of human β-defensin 3 (hBD-3) against multidrug-resistant clinical isolates of Staphylococcus aureus, Enterococcus faecium, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Acinetobacter baumannii was evaluated. A fast bactericidal effect (within 20 min) against all bacterial strains tested was observed. The presence of 20% human serum abolished the bactericidal activity of hBD-3 against gram-negative strains and reduced the activity of the peptide against gram-positive strains.

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 Effects of Carvacrol on Staphylococcus aureus isolated from bulk tank milk

2019 ◽  
Vol 75 (02) ◽  
pp. 6211-2019
Author(s):  
ERHAN KEYVAN ◽  
HIDAYET TUTUN
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Multidrug Resistant ◽  
Culture Collection ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Bulk Tank Milk ◽  
Microdilution Method ◽  
Bulk Tank ◽  
Susceptibility Profiles

The occurrence of multidrug-resistant Staphylococcus aureus is an important causative agent of mastitis in cattle and of foodborne diseases. It is a worldwide concern, making it essential to develop alternative treatments to fight against the bacteria. Thus, the aim of this study is to determine the ability of carvacrol to inhibit the growth of S. aureus isolated from bulk tank milk in Turkey’s Burdur Province. All strains (n = 31) were used to investigate the antimicrobial activity of carvacrol, including the methicillin-resistant S. aureus and strains from the American Type Culture Collection and England’s National Collection of Type Cultures. The minimum inhibitory concentration (MIC) values were determined via a microdilution method, and the antimicrobial susceptibility profiles via a disk diffusion method. Antibiotic resistance was detected in 20 strains (64.5%). Multidrug resistance was observed in 8 strains (25.8%). Carvacrol exhibited strong antimicrobial activity, with MIC value at 0.058-0.234 mg/ml, in the microdilution method. Inhibition zones of carvacrol were in the range of 19 to 45 mm. The results of this study emphasize the promising role of carvacrol among new antibacterial agents that can combat S. aureus strains.

scholarly journals Kisameet Clay Isolated from the Central Coast of British Columbia, Canada, Demonstrates Broad-Spectrum Antimicrobial Activity

mBio ◽  
2016 ◽  
Vol 7 (2) ◽  
Author(s):  
George G. Zhanel ◽  
James A. Karlowsky
Keyword(s):  
Staphylococcus Aureus ◽  
British Columbia ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Klebsiella Pneumoniae ◽  
Acinetobacter Baumannii ◽  
Enterococcus Faecium ◽  
Fine Particles ◽  
Multidrug Resistant ◽  
Central Coast

ABSTRACT Clay minerals are naturally occurring layered phyllosilicates which consist of fine particles and possess antimicrobial activity. In a recent article, Behroozian et al. obtained Kisameet clay (KC) from Kisameet, from the central coast of British Columbia, Canada, northwest of Vancouver and assessed its antimicrobial activity versus 16 selected ESKAPE pathogens ( Enterococcus faecium , Staphylococcus aureus , Klebsiella pneumoniae , Acinetobacter baumannii , Pseudomonas aeruginosa , and Enterobacter spp.) possessing a variety of different resistance profiles [S. Behroozian, S. L. Svensson, and J. Davies, mBio 7(1):e01842-15, 2016, http://dx.doi.org/10.1128/mBio.01842-15]. KC demonstrated complete bacterial eradication of Klebsiella pneumoniae , Acinetobacter baumannii , Pseudomonas aeruginosa , and Staphylococcus aureus within 24 h. For Enterobacter spp., the organisms were eradicated with 1% KC within 5 h, while for Enterococcus faecium , it took 48 h to kill all organisms. Although many questions need to be answered, these exciting findings highlight the importance of testing natural substances/products from around the globe to assess whether they possess antimicrobial activity and potential for usage as topical, oral, or systemic agents for the treatment of multidrug-resistant pathogens.

scholarly journals Antibacterial Activity Against Multidrug-Resistant Staphylococcus aureus and in Silico Evaluation of MepA Efflux Pump by Cinnamaldehyde Chalcone

2021 ◽  
Vol 12 (6) ◽  
pp. 7523-7531
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Natural Products ◽  
Efflux Pump ◽  
Competitive Inhibitor ◽  
Multidrug Resistant ◽  
Bacterial Strains ◽  
Efflux Pump Inhibition ◽  
Phytochemical Studies

Phytochemical studies on Croton species have identified the presence of secondary metabolites responsible for a wide variety of pharmacological activities, among them antimicrobial activity. Research for new substances with antimicrobial activity derived from natural products can give a major contribution to human health worldwide by finding more efficient and fewer toxic formulas in the race against pathogenic microorganisms' resistance. Among bacterial pathogens, Staphylococcus aureus species, despite being present in the skin and nasal mucosa, can cause many infections and diseases. These opportunists reach debilitated people in hospitals and are challenging to treat. Here, we performed the structural characterization, determination of antibiotic activity, and MepA efflux pump inhibition potential against S. aureus of the chalcone (2E, 4E) -1- (2-hydroxy-3,4,6-trimethoxyphenyl)-5-phenylpenta-2,4-dien-1-one, derived from natural products 2-hydroxy-3,4,6-trimethoxyacetophenone isolated from Croton anisodontus and cinnamaldehyde. The chalcone was synthesized by the Claisen-Schmidt condensation. In addition, microbiological tests were performed to investigate the antibacterial activity, modulator potential, and efflux pump inhibition against the S. aureus multi-resistant strains. MIC values obtained to chalcone were not clinically relevant (MIC ≥ 1024 µg/mL). However, chalcone hampers the binding of the antibiotic to the binding site of the MepA efflux pump. It acts as a competitive inhibitor, being expelled from the bacteria in place of the antibiotic and potentiating ciprofloxacin's action against multidrug-resistant bacterial strains of K2068. Therefore, chalcone can be used as a base for substance design with antibiotic modifying activity.

scholarly journals Unprocessed milk as a source of multidrug-resistant Staphylococcus aureus strains

2021 ◽  
Vol 90 (3) ◽  
pp. 357-363
Author(s):  
Marta Kiš ◽  
Ivana Kolačko ◽  
Nevijo Zdolec
Keyword(s):  
Staphylococcus Aureus ◽  
Health Management ◽  
Raw Milk ◽  
Multidrug Resistant ◽  
Control Measures ◽  
Multi Drug Resistance ◽  
Vending Machines ◽  
Microbiological Control ◽  
Microbiological Testing ◽  
One Year

Staphylococcus aureus is the most relevant pathogen of animal mastitis and milk-related intoxications. Its presence in directly sold milk is rather not to be expected if strict udder health management and regular microbiological control of raw milk are performed. In this one-year survey, we present the results of monthly microbiological testing of milk from vending machines in Croatia for S. aureus and its multi-drug resistance. Staphylococcus aureus was detected in 27.58% of the samples. Among 60 tested isolates from 10 farmers, a total of 41 isolates were resistant to at least one antimicrobial agent (68.33%). A Multiple Antibiotic Resistance (MAR) index of 0.2 or higher had 48.8% of the resistant isolates, which is considered a high-risk potential for the spread of antimicrobial resistance. The majority of the isolates were resistant to penicillin and ampicillin followed by ciprofloxacin, ceftazidime, and kanamycin. The results impose the need for improving the control measures in the raw milk distribution chain focused on MAR risk reduction.

scholarly journals Multidrug Resistant Coagulase-Positive Staphylococcus aureus and Their Enterotoxins Detection in Traditional Cheeses Marketed in Banat Region, Romania

Antibiotics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1458
Author(s):  
Adriana Morar ◽  
Alexandra Ban-Cucerzan ◽  
Viorel Herman ◽  
Emil Tîrziu ◽  
Khalid Ibrahim Sallam ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Susceptibility ◽  
Meca Gene ◽  
Raw Milk ◽  
Multidrug Resistant ◽  
Contamination Level ◽  
Traditional Cheeses ◽  
Antimicrobial Susceptibility Profile ◽  
Vitek 2 ◽  
Coagulase Positive Staphylococci

The main objectives of the present study were to determine the occurrence of coagulase positive staphylococci (CPS) and to assess the presence and antimicrobial susceptibility profile of Staphylococcus aureus isolates in different raw milk origin (cow and sheep) traditional cheeses marketed in Banat region, Romania. Additionally, the presence of mecA gene in S. aureus isolates and the staphylococcal enterotoxins (SEs) in cheese samples were evaluated. A total of 81.6% (138/169) of the screened samples were positive for CPS. Furthermore, 35.5% (49/138) of the investigated CPS positive cheese samples were contaminated with S. aureus, with an isolation frequency of 46.6% (14/30) in caș, 33.3% (32/96) in telemea, 25% (2/8) in burduf, and 25% (1/4) in urdă assortments, respectively. From the total number of S. aureus isolates, 6.1% (3/49) harbored the mecA gene. Detectable levels of SEs were identified in 4.3% (4/94) of cheese samples with a CPS contamination level higher than 105 log CFU g−1. The expressed antimicrobial susceptibility profile of the tested cheese-origin S. aureus isolates, with the automated Vitek 2 equipment, showed resistance towards amikacin (90.1%, 10 out from 11 tested), enrofloxacin (86.2%, 25/29), ceftiofur (72.7%, 8/11), neomycin (63.6%, 7/11), benzylpenicillin (53.1%, 26/49), kanamycin (41.4%, 12/29), rifampicin (39.5%, 15/38), tetracycline (38.8%, 19/49), tilmicosin (36.4%, 4/11), clindamycin (30.6%, 15/49), ciprofloxacin (30%, 6/20), erythromycin (22.4%, 11/49), tylosin (18.2%, 2/11), oxacillin (16.3%, 8/49), linezolid (15%, 3/20), teicoplanin (15%, 3/20), fusidic acid (13.1%), imipenem (10.5%, 4/38), vancomycin (7.9%, 3/38), ampicillin (5.5%, 1/18), mupirocin (5.5%, 1/18), fosfomycin (5%, 1/20), and gentamicin (4.1%, 2/49). Twenty-four (49%) S. aureus isolates exhibited multidrug resistance. The investigation highlighted a common occurrence of multidrug-resistant S. aureus strains in the monitored cheese assortments, which can constitute a potential risk for consumers’ health.

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