scholarly journals Effect of Vancomycin Minimal Inhibitory Concentration on the Outcome of Methicillin-Susceptible Staphylococcus aureus Endocarditis

2014 ◽  
Vol 58 (12) ◽  
pp. 1668-1675 ◽  
Author(s):  
C. Cervera ◽  
X. Castaneda ◽  
C. G. de la Maria ◽  
A. del Rio ◽  
A. Moreno ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Minimal Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Staphylococcus Aureus Endocarditis

Antimicrobial Activity of N,N'-bis(decylmethyl)- α,ω-alkanediamine Dioxides [1]

1983 ◽  
Vol 38 (1-2) ◽  
pp. 151-152 ◽  
Author(s):  
Ferdinand Devínsky ◽  
Ivan Lacko ◽  
Ludovít Krasnec ◽  
Dušan Mlynarčík
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Minimal Inhibitory Concentration ◽  
Inhibitory Concentration

Antimicrobial activity of N,N′-bis(decylmethyl)-α,ω-alkanediamine dioxides determined on Staphylococcus aureus, Escherichia coli, and Candida albicans is presented as minimal inhibitory concentration (MIC). The effect of the length of linking alkylene chain on this activity has been followed.

scholarly journals Reduced Triclosan Susceptibility in Methicillin-Resistant Staphylococcus epidermidis

2004 ◽  
Vol 48 (4) ◽  
pp. 1397-1399 ◽  
Author(s):  
Molly B. Schmid ◽  
Nachum Kaplan
Keyword(s):  
Staphylococcus Aureus ◽  
Minimal Inhibitory Concentration ◽  
Staphylococcus Epidermidis ◽  
Inhibitory Concentration ◽  
Clinical Isolates ◽  
Methicillin Resistant

ABSTRACT Triclosan MIC determination showed that recent Staphylococcus aureus clinical isolates (n = 100) were highly susceptible to triclosan, with a 50% minimal inhibitory concentration (MIC50) of 0.12 μg/ml and a MIC90 of 0.25 μg/ml. Staphylococcus epidermidis isolates (n = 96) were less susceptible, with a MIC50 of 0.12 μg/ml and a MIC90 of 8 μg/ml. Decreased susceptibility to triclosan was more prevalent among methicillin-resistant S. epidermidis than among methicillin-sensitive S. epidermidis isolates.

Induction of staphylococcal β-lactamase in response to low concentrations of methicillin under simulated diving environments

1977 ◽  
Vol 23 (1) ◽  
pp. 116-121
Author(s):  
James R. Wild
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Hydrostatic Pressure ◽  
Minimal Inhibitory Concentration ◽  
Gas Phase ◽  
Inhibitory Concentration ◽  
Hyperbaric Pressure ◽  
Low Concentrations ◽  
Antibiotic Efficacy

The influence of simulated diving environments on the antimicrobial activity of a variety of penicillin and cephalosporin congeners was studied in Staphylococcus aureus. Pressure reduced bacteriostatic action provided the antibiotic was susceptible to β-lactamase hydrolysis and the bacterium was inducible for penicillinase. Ethidium bromide curing of the penicillinase plasmid of an inducible strain eliminated the hyperbaric effect. The minimal inhibitory concentration of benzylpenicillin increased about threefold with increasing hyperbaric pressure from 17 to 136 atm. Additional pressurization to 204 atm did not change antibiotic efficacy further. The efficacy of benzylpenicillin was reduced by 68 atm of hyperbaric helium, nitrogen, or a mixture of neon and helium, but was slightly increased by 68 atm of argon, removal of the gas phase, or 68 atm of hydrostatic pressure. Hyperbaric helium had no effect on β-lactamase activity in vitro. An effect was demonstrated upon induction by suboptimal concentrations of methicillin. The concentration of methicillin required for the induction of half-maximal levels of penicillinase in late log cultures of S. aureus was reduced from 0.15 μg/ml at 1 atm to 0.06 μg/ml at 68 atm. The basis of increased resistance to antibiotics exhibited by S. aureus in hyperbaric environments appears to be enhanced efficiency of penicillinase induction.

scholarly journals ANTIMICROBIAL SUSCEPTIBILITY PATTERN OF STAPHYLOCOCCUS AUREUS STRAINS IN ISLAMABAD, PAKISTAN

2021 ◽  
Vol 71 (3) ◽  
pp. 1056-60
Author(s):  
Ambreen Gul ◽  
Yasir Rasheed ◽  
Kaleem Imdad ◽  
Raheela Yasmin ◽  
Aneela Jamil ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Minimal Inhibitory Concentration ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Inhibitory Concentration ◽  
Media Analysis ◽  
Aureus Strain ◽  
Disc Diffusion ◽  
Diffusion Test ◽  
Methicillin Resistant ◽  
Group 1

Objective: To investigate the prevalence of S. aureus in hospitalized patients of Islamabad. Study Design: Cross-sectional study. Study Duration: Pakistan Institute of Medical Science, Applied Microbiology and Biotechnology Lab, COMSATS Institute of Information Technology, Islamabad, from Sep 2017 to Sep 2018. Methodology: A total of 500 samples were collected. The isolates were divided into four study groups according to their source of origin i.e. group 1 (dermal group), group 2 (nasal group), group 3 (blood group) and group 4 (urine group). Gram staining, catalase test and DNA se media analysis were done for validation of S. aureus. Disc diffusion test (for antibiotic susceptibility), Oxacillin disc test (to differentiate between methicillin-resistant Staphylococcus aureus and methicillin-susceptible staphylococcus aureus) and minimal inhibitory concentration (for susceptibility to vancomycin), were performed. Results: Degree of the prevalence of staphylococcus aureus was 21%, 17%, 9% and 8% in group 1, 2, 3 & 4 respectively. The overall prevalence of staphylococcus aureus was 19.5% in all isolates. The disc diffusion test showed the descending resistance pattern of isolates i.e. 100, 94, 94, 76, 58, 55, 47, 43, 40 and 37% for penicillin, ciprofloxacin, Kanamycin, erythromycin, tetracycline, oxazolidinone, sulfamethoxazole, doxycycline, clindamycin, and cipoxin respectively. Minimal inhibitory concentration found only one sample resistant at 2ug/l concentration of Vancomycin. Moreover, Oxacillin disc test showed 52% methicillin-susceptibleStaphylococcus aureus while 48.2% methicillin-resistant staphylococcus aureus among all isolates. Conclusion: There is an increase in the frequency of methicillin-resistant staphylococcus aureus. Single vancomycin resistant staphylococcus aureus strain was also isolated.

scholarly journals Antimicrobial Activity and LC-MS Data Comparison from Lichen Parmotrema praesorediosum in Malaysia

2021 ◽  
Vol 50 (2) ◽  
pp. 383-393
Author(s):  
Anis Asmi Azman ◽  
Nurul Nadiah ◽  
Andi Rifki Rosandy ◽  
Afnani Alwi ◽  
Nurkhalida Kamal ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Minimal Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Methanol Extract ◽  
Bacterial Species ◽  
Acetone Extract ◽  
Data Comparison ◽  
Broth Microdilution Method ◽  
Pure Compounds

The research study regarding antimicrobial activity of pure compounds and LCMS data comparison from extract of lichen Parmotrema praesorediosum in Bangi, Selangor, Malaysia. Antimicrobial activity of acetone, ethanol, and methanol extracts as well as five compounds, namely methyl divaricatinate, methyl haematommate, methyl chlorohaematommate, methyl β-orsellinate, and vinapraesorediosic acid from methanol extract were identified for the microbial activity against four bacterial species, Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus, Enterobacter aerogens, and Escerichia coli as well as two fungal species, Candida albicans and Candida parapsilosisbased on standards. The determination of IC50 using minimal inhibitory concentration (MIC) by broth microdilution method was carried out. For acetone extract, 201 μg/mL concentration was required to inhibit 50% (IC50) growth of positive gram bacteria, S. aureus while the concentrations of 430 and 480 μg/mL were able to inhibit 50% (IC50) growth of C. albicans and C. parapsilosis, respectively. Ethanol and methanol extract as well as five pure compounds did not inhibit 50% (IC50) of bacterial and yeast growths. Five pure compounds were first reported to determine IC50 of minimal inhibitory concentration (MIC) from lichen, Parmotrema praesorediosum in Malaysia. The comparison of LC-MS data between ethanol and acetone extracts showed that there was a peak of the main compound, atranorin in the acetone extract, but was invisible in the ethanol extract where the main bond broke down and produced other compounds. Result of pure compounds from antimicrobial activity and LCMS data comparison from extract of lichen Parmotrema praesorediosum were first reported in Bangi, Selangor, Malaysia. Data produced from this study will be used to show the comparison and latest result that will provide ongoing body of research into the issue of natural product.

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