scholarly journals Antimicrobial Activity of Divaricatic Acid Isolated from the Lichen Evernia mesomorpha against Methicillin-Resistant Staphylococcus aureus

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3068 ◽  
Author(s):  
Jong Oh ◽  
Yi Kim ◽  
Hyo-Seung Gang ◽  
Jin Han ◽  
Hyung-Ho Ha ◽  
...  

One hundred and seventy seven acetone extracts of lichen and 258 ethyl acetate extracts of cultured lichen-forming fungi (LFF) were screened for antimicrobial activity against Staphylococcus aureus and Enterococcus faecium using a disk diffusion method. Divaricatic acid was isolated from Evernia mesomorpha and identified by LC-MS, 1H-, 13C- and DEPT-NMR. Purified divaricatic acid was effective against Gram + bacteria, such as Bacillus subtilis, Staphylococcus epidermidis, Streptococcus mutans, and Enterococcus faecium, with the minimum inhibitory concentration (MIC) values ranging from 7.0 to 64.0 μg/mL, whereas vancomycin was effective in the MICs ranging from 0.78 to 25.0 μg/mL. Interestingly, the antibacterial activity of divaricatic acid was higher than vancomycin against S. epidermidis and E. faecium, and divaricatic acid was active against Candida albicans. In addition, divaricatic acid was active as vancomycin against S. aureus (3A048; an MRSA). These results suggested that divaricatic acid is a potential antimicrobial agent for the treatment of MRSA infections.

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1094
Author(s):  
Melissa M. Cadelis ◽  
Soeren Geese ◽  
Benedict B. Uy ◽  
Daniel R. Mulholland ◽  
Shara J. van de Pas ◽  
...  

Antimicrobial bioassay-guided fractionation of the endophytic fungi Neofusicoccum australe led to the isolation of a new unsymmetrical naphthoquinone dimer, neofusnaphthoquinone B (1), along with four known natural products (2–5). Structure elucidation was conducted by nuclear magnetic resonance (NMR) spectroscopic methods, and the antimicrobial activity of all the natural products was investigated, revealing 1 to be moderately active towards methicillin-resistant Staphylococcus aureus (MRSA) with a minimum inhibitory concentration (MIC) of 16 µg/mL.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Irma Zarwinda ◽  
Fauziah Fauziah ◽  
Shara Shevalinda ◽  
Dwi Putri Rejeki

Startfruit (Averrhoa bilimbi L.) is one the kind of plant that is widely used as a traditional herbal medicineto overcome various diseases i.e. diabetes mellitus, cough, rheumatism, thrush, diabetes, toothache, acne, etc. The secondary metabolites of the starfruit leaves contain flavonoids and tannins, whereby these activecompounds can be used as an antibacterial. This study aimed to determine the inhibiting power of starfruit leaf ethanol extract against Staphylococcus epidermidis at concentrations of 25%, 50%, 75%, and 100%. The research was conducted at the  AKAFARMA Laboratory and the Chemistry Laboratory , Faculty of Teacher Training and Education, Syiah Kuala University from June to July 2020. The research method was laboratory experimental using the disk diffusion method. The population of starfruit leaves was obtained from Lhokseumawe  using a purposive sampling technique. Ethanol extract of starfruit leaves with concentrations of 25%, 50%, 75%, and 100%. The diameter of the inhibition zone of the ethanol extract  from the starfruit leaves at  concentrations of 100%, 75%, 50%, and 25% were 15 mm, 12 mm, 11 mm and 10 mm, respectively. It can be concluded that  ethanol extract of starfruit leaves can inhibit the growth  of  Staphylococcus  epidermidis  with  a  maximum inhibitory concentration  of  100%,  which is classified  as a strong category.


2012 ◽  
Vol 45 (2) ◽  
pp. 189-193 ◽  
Author(s):  
Karinne Spirandelli Carvalho Naves ◽  
Natália Vaz da Trindade ◽  
Paulo Pinto Gontijo Filho

INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) is spread out in hospitals across different regions of the world and is regarded as the major agent of nosocomial infections, causing infections such as skin and soft tissue pneumonia and sepsis. The aim of this study was to identify risk factors for methicillin-resistance in Staphylococcus aureus bloodstream infection (BSI) and the predictive factors for death. METHODS: A retrospective cohort of fifty-one patients presenting bacteraemia due to S. aureus between September 2006 and September 2008 was analysed. Staphylococcu aureus samples were obtained from blood cultures performed by clinical hospital microbiology laboratory from the Uberlândia Federal University. Methicillinresistance was determined by growth on oxacillin screen agar and antimicrobial susceptibility by means of the disk diffusion method. RESULTS: We found similar numbers of MRSA (56.8%) and methicillin-susceptible Staphylococcus aureus (MSSA) (43.2%) infections, and the overall hospital mortality ratio was 47%, predominantly in MRSA group (70.8% vs. 29.2%) (p=0.05). Age (p=0.02) was significantly higher in MRSA patients as also was the use of central venous catheter (p=0.02). The use of two or more antimicrobial agents (p=0.03) and the length of hospital stay prior to bacteraemia superior to seven days (p=0.006) were associated with mortality. High odds ratio value was observed in cardiopathy as comorbidity. CONCLUSIONS: Despite several risk factors associated with MRSA and MSSA infection, the use of two or more antimicrobial agents was the unique independent variable associated with mortality.


Author(s):  
Abolfazl Jafari-Sales ◽  
Zahra Sadeghi Deylamdeh ◽  
Afsoon Shariat

Introduction: Staphylococcus aureus causes a wide range of infections and as a multivalent pathogen is one of the causative agents of nosocomial and community infections. Therefore, the aim of this study was to identify and determine the pattern of antibiotic resistance of methicillin-resistant Staphylococcus aureus (MRSA) isolates from patients in hospitals and medical centers in Marand city and also to evaluate the presence of mecA gene. Materials and Methods: In this cross-sectional descriptive study, 385 samples of S. aureus were collected from different clinical samples of patients in hospitals and medical centers of Marand city. S. aureus was identified using standard biochemical methods.  Methicillin resistance was determined by disk diffusion method in the presence of oxacillin and cefoxitin. The pattern of antibiotic resistance of the strains was determined by disk diffusion method and according to CLSI recommendation and also PCR method was used to evaluate the frequency of MecA gene. Results: In the present study, out of 385 samples of S. aureus, 215 (55.84%) samples were methicillin resistant. PCR results for mecA gene showed that 110 samples had mecA gene.  The highest antibiotic resistance was observed against penicillin (100%) and erythromycin (83.63%). Most MRSA were isolated from urine and wound samples. Conclusion: The results of this study indicate the prevalence of methicillin-resistant species and also the increase in antibiotic resistance of MRSA to various antibiotics.  Therefore, in order to prevent increased resistance to other antibiotics, it is recommended to avoid inappropriate use of antibiotics.


2021 ◽  
Vol 30 (1) ◽  
pp. 109-114
Author(s):  
Nancy M. Attia ◽  
Abeer Abd El Rahim Ghazal ◽  
Omnia M. Khaleel ◽  
Ahmed Gaballah

Background: Methicillin-resistant Staphylococcus aureus (MRSA) colonization is considered a major risk factor for nosocomial infections and its decolonization has reduced these infections. Mupirocin (MUP) is the topical antibiotic of choice for decolonization. MUP decolonization failure is attributed to MUP resistance. Objective: The aim of the current study is to assess MUP resistance among MRSA isolates phenotypically and genotypically. Methodology: Fifty MRSA isolates were identified in Microbiology Department in the Medical Research Institute hospital, Alexandria University. Antibiotic susceptibility to different classes of antibiotics by disk diffusion method was done. MUP minimum inhibitory concentration (MIC) was determined phenotypically by MUP Ezy MIC™ Strips. MUP resistance was determined genetically by multiplex PCR detection of mupA and mupB. Results: Of all MRSA isolates, 6% exhibited high level and none showed low level MUP resistance. Only mupA was detected in all resistant isolates. Conclusion: Despite low prevalence of MUP resistance, it is appropriate to test MUP resistance prior nasal decolonization


Author(s):  
SUNDAR MADASAMY ◽  
SURESH SUNDAN ◽  
LINGAKUMAR KRISHNASAMY

Objective: A simple formulation of cold cream from methanolic extract Caralluma adscendens var. attenuata (MECA) and their antimicrobial activity was tested against various clinical pathogens, namely, Escherichia coli, methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium, and Candida albicans. Methods: Methanol extract of these plant extract was prepared by the Soxhlet method. We analyzed phytochemical nature of theses plant, and subsequently, a cream was formulated cold-cream C. adscendens var. attenuata (FCA) different concentration such as FCA 50 mg, FCA 100 mg, and FCA 200 mg. In the present study, aimed to the antimicrobial activity of cold cream was measured by agar well diffusion method, and standard antibiotic Neosporin (market available) cream was used as positive control and dummy cold cream (without-MECA) were used as the negative control. Results: Phytochemical screening showed that the plant extracts were found a rich source of secondary metabolites. For more, the efficacy of cold cream from MECA extracts to against the clinical pathogen. Positive control Neosporin and 200 mg FCA cream was a highly significant difference in the zone of inhibition when compared to dummy cream. The 200 mg FCA was activity against Escherichia coli, methicillin-resistant Staphylococcus aureus, vancomycin-resistant E. faecium, and C. albicans highly significantly difference (p<0.05) compared FCA 50 mg and FAC 100 mg creams. Conclusion: The results from this study suggested that the cold cream form base of MECA crude had antimicrobial activity in the different clinical pathogen. They could be used as an alternative source to conventional antimicrobial agents for the treatment of pathological infection.


2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Pavithra L. Jayatilake ◽  
Helani Munasinghe

Endophytic and rhizosphere fungi are understood to be aiding the host plant to overcome a range of biotic and abiotic stresses (nutrition depletion, droughts, etc.) hence, they remain to be reservoirs of plethora of natural products with immense use. Consequently, this investigation of endophytic and rhizosphere fungi isolated from Mikania cordata (a perennial vine that is well established in Sri Lanka) for their antimicrobial properties was performed with the aim of future derivation of potential beneficial pharmaceutical products. Leaves, twigs, and roots of M. cordata were utilized to isolate a total of 9 endophytic fungi out of which the highest amount (44%) accounted was from the twigs. A sample of the immediate layer of soil adhering to the root of M. cordata was utilized to isolate 15 rhizosphere fungi. Fusarium equiseti and Phoma medicaginis were endophytes that were identified based on colony and molecular characteristics. The broad spectrum of antimicrobial activity depicted by F. equiseti (MK517551) was found to be significantly greater (p≤0.05, inhibitory against Bacillus cereus ATCC 11778, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 25853) than P. medicaginis (MK517550) (inhibitory against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 25853) as assessed using the Kirby-Bauer disk diffusion method. Trichoderma virens and Trichoderma asperellum were rhizospere fungi that exhibited remarkable antimicrobial properties against the test pathogens chosen for the study. T. asperellum indicated significantly greater bioactivity against all four bacterial pathogens and Candida albicans ATCC 10231 under study. The ranges of minimum inhibitory concentrations (MICs) of the fungi depicting antimicrobial properties were determined. The results obtained suggest that F. equiseti, P. medicaginis, T. asperellum, and T. virens of M. cordata harness bioprospective values as natural drug candidates. This is the first report on isolation and evaluation of the antimicrobial properties of endophytic and rhizosphere fungi of Mikania cordata.


1999 ◽  
Vol 6 (3) ◽  
pp. 163-167 ◽  
Author(s):  
Bahri Ülküseven ◽  
Aydin Tavman ◽  
Gülten Ötük

The metal complexes of nine 2-substituted-1H-benzimidazoles (I-IX) with Ni(II), Pd(II), Cu(II), Ag(I), Zn(II) salts were synthesized. The compounds were characterized by melting point, analytical data, IR spectroscopy and magnetic susceptibility. The antimicrobial activity of the compounds was determined by the disk diffusion method in Mueller-Hinton Agar on Staphylococcus aureusATCC 6538, Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 8739, Klebsiella pneumoniae ATCC 4352, Pseudomonas aeruginosa ATCC 1539, Salmonella typhi, Shigella flexneri, Proteus mirabilis, Candida albicans ATCC 10231. Cu(II)and Ag(I)complexes of II, III and IV showed considerable activity against S. aureus, S. epidermidis, Ps. aeruginosa, S. typhi, Sh. flexneri and C. albicans microorganisms, the ligands themselves having no effect.


2020 ◽  
Vol 8 (4) ◽  
pp. 176
Author(s):  
Carla Indianara Bonetti ◽  
Mariana Dalmagro ◽  
Juliana Cristhina Friedrich ◽  
Douglas Rossi Jesus ◽  
Mariana Moraes Pinc ◽  
...  

Echinodorus grandiflorus has pharmacological properties due to its secondary metabolism, such as anti-inflammatory, antioxidant, diuretic, analgesic, anti-rheumatic, antihypertensive, and cardioprotective effects. The aim of this study was to determine the phytochemical profile and evaluate the antimicrobial activity of crude extract of E. grandiflorus form its leaves. In the analysis of the phytochemical profile, qualitative tests were performed to identify tannins, alkaloids, flavonoids, anthraquinones, steroids, triterpenes, saponins, polysaccharides, and coumarins. Antimicrobial tests were performed using the disk diffusion method and minimum inhibitory concentration (MIC) in 96-well microplates, using hydroalcoholic crude extract obtained by maceration in the proportions 1:5 and 1:10. The higher content of crude extract was observed by maceration 1:5 (3.26%). In phytochemical tests, the presence of tannins, alkaloids, flavonoids, and saponins was detected. The microbial strains evaluated were Staphylococcus aureus, S. epidermidis, Lactobacillus casei, Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. The antimicrobial activity of crude extract has not apparent against the tested organisms. It is concluded that the crude extract present several phytochemical, however did not show antimicrobial activity, and furthermore studies should be carried out researching isolated chemical compounds and the antimicrobial activity leaves crude extract of Echinodorus grandiflorus plant.


Antibiotics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 375
Author(s):  
Vanessa Silva ◽  
Sara Hermenegildo ◽  
Catarina Ferreira ◽  
Célia M. Manaia ◽  
Rosa Capita ◽  
...  

In this study we aimed to characterize antimicrobial resistance in methicillin-resistant Staphylococcus aureus (MRSA) isolated from bloodstream infections as well as the associated genetic lineages of the isolates. Sixteen MRSA isolates were recovered from bacteremia samples from inpatients between 2016 and 2019. The antimicrobial susceptibility of these isolates was tested by the Kirby–Bauer disk diffusion method against 14 antimicrobial agents. To determine the macrolide–lincosamide–streptogramin B (MLSB) resistance phenotype of the isolates, erythromycin-resistant isolates were assessed by double-disk diffusion (D-test). The resistance and virulence genes were screened by polymerase chain reaction (PCR). All isolates were characterized by multilocus sequence typing (MLST), spa typing, staphylococcal chromosomal cassette mec (SCCmec) typing, and accessory gene regulator (agr) typing. Isolates showed resistance to cefoxitin, penicillin, ciprofloxacin, erythromycin, fusidic acid, clindamycin, and aminoglycosides, confirmed by the presence of the blaZ, ermA, ermC, mphC, msrA/B, aac(6’)-Ie-aph(2’’)-Ia, and ant(4’)-Ia genes. Three isolates were Panton–Valentine-leukocidin-positive. Most strains (n = 12) presented an inducible MLSB phenotype. The isolates were ascribed to eight spa-types (t747, t002, t020, t1084, t008, t10682, t18526, and t1370) and four MLSTs (ST22, ST5, ST105, and ST8). Overall, most (n = 12) MRSA isolates had a multidrug-resistance profile with inducible MLSB phenotypes and belonged to epidemic MRSA clones.


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