scholarly journals Evaluation of antibacterial properties of hydroxyapatite/bioactive glass and fluorapatite/bioactive glass nanocomposite foams as a cellular scaffold of bone tissue

2018 ◽  
Vol 10 (03) ◽  
pp. 265-270 ◽  
Author(s):  
Seyedali Seyedmajidi ◽  
Ramazan Rajabnia ◽  
Maryam Seyedmajidi
Keyword(s):  
Staphylococcus Aureus ◽  
Bioactive Glass ◽  
Bone Tissue ◽  
Streptococcus Mutans ◽  
Enterococcus Faecalis ◽  
Agar Medium ◽  
Antibacterial Properties ◽  
Disk Diffusion ◽  
Diffusion Test ◽  
Nanocomposite Foams

ABSTRACT AIMS AND OBJECTIVES: Infection is a serious problem for patients after implantation surgery, which is difficult to treat with antibiotic therapy. The present study was developed to evaluate and compare the antibacterial properties of hydroxyapatite/bioactive glass (HA/BG) and fluorapatite/bioactive glass (FA/ BG) nanocomposite foams as a cellular scaffold for use in bone defects by two macrodilution and disk diffusion methods. MATERIALS AND METHODS: Staphylococcus aureus, Enterococcus faecalis, and Streptococcus mutans were cultured in brain heart infusion broth medium with nanocomposite powder for 5 days, and their bioactivity levels were evaluated by daily culturing on solid agar medium plates. To carry out the disk diffusion test, a disc form of nanocomposite foams was used on agar medium with 48 h incubation. Results: None of two nanocomposites even at their highest concentration (200 mg/mL) did not prevent the growth of two Staphylococcus aureus and Enterococcus faecalis microorganisms. However, HA/BG nanocomposite on the 3rd day at a concentration of 200 mg/mL and on 4th and 5th day at a concentration of 100 mg/mL and FA/BG nanocomposite on the 4th day at a concentration of 100 mg/mL and on the 5th day at a concentration of 50 mg/mL could be able to kill Streptococcus mutans microorganism. In the disc diffusion test, none of the nanocomposites could create a nongrowth zone. Both tested biomaterials showed increased antibacterial properties over time and concentration increase. Conclusions: HA/BG and FA/BG nanocomposites, due to their biocompatibility and antimicrobial properties, are good choices for implantation instead of damaged bone tissue in tissue engineering.

scholarly journals Antimicrobial activity of mouth rinses incorporating zein coated magnesium oxide nanoparticles

2020 ◽  
Author(s):  
Ghada H Naguib ◽  
Mohamed T Hamed ◽  
Abdulkarim A Hatrom ◽  
Abeer M Alnowaiser ◽  
Sahar MN Bukhary ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Streptococcus Mutans ◽  
Enterococcus Faecalis ◽  
Antimicrobial Effect ◽  
Oral Bacteria ◽  
Disc Diffusion ◽  
Diffusion Test ◽  
Mgo Nanoparticles

Abstract Background The addition of antibacterial agents to oral prophylaxis materials showed inhibition of plaque accumulation and bacterial acid production. This study aimed to test the antimicrobial effect of distinctive oral mouth washes on an exemplary of oral bacteria after the addition of zein-coated MgO nanoparticles.Materials and Methods Three hundred and twelve groups were used in this study. MgO nanoparticles in five concentrations with zein and without zein-coating, were incorporated in three oral mouth washes: Listerine Zero, Listerine Total Control and Oral B in the mass percentages of 0.3%, 0.5%, 1%, 2%, 5% and 10%, in addition to controls with no MgO nanoparticles. The three mouthwashes with variable concentrations were studied in opposition of Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis and Candida albicans using two different tests, the Disc Diffusion Test (DDT) and Direct Contact Test (DCT). Data was analyzed with Kruskall-Wallis and Mann-Whitney U tests.Results Results showed a highly significant statistical difference of antimicrobial activity for all tested mouth washes with Zein coated MgO nanoparticles on Streptococcus mutans, Staphylococcus aureus, Enterococcus faecalis, and Candida albicans in the disc diffusion test. While in the DCT, all tested mouth washes with MgO nanoparticles with and without zein coating showed antimicrobial activity on all tested microorganisms.Conclusion Zein coated MgO nanoparticles is a potent antimicrobial agent when added to oral mouth washes. It is recommended to incorporate Zein MgO nanoparticles to Oral mouth washes to improve its antibacterial property.

scholarly journals Evaluation of Mannitol Salt Agar for Detection of Oxacillin Resistance in Staphylococcus aureus by Disk Diffusion and Agar Screening

1998 ◽  
Vol 36 (8) ◽  
pp. 2254-2257 ◽  
Author(s):  
Günter Kampf ◽  
Christoph Lecke ◽  
Ann-Katrin Cimbal ◽  
Klaus Weist ◽  
Henning Rüden
Keyword(s):  
Staphylococcus Aureus ◽  
Disk Diffusion ◽  
Diffusion Test ◽  
Mannitol Salt Agar ◽  
Disk Diffusion Test ◽  
Zone Diameter ◽  
Oxacillin Resistance

Mannitol salt agar was evaluated for detection of oxacillin resistance in 136 Staphylococcus aureus isolates. AllmecA-positive isolates (n = 54) were correctly categorized as oxacillin resistant by the disk diffusion test (1-μg disk; zone diameter, <16 mm); the specificity was 97.6%. Agar screening (2 μg of oxacillin per ml) revealed a sensitivity of 98.1% and a specificity of 95.1%.

scholarly journals Antimicrobial activity of oregan and clove essential oils against some foodborne pathogens

2020 ◽  
Vol 41 (1) ◽  
pp. 3
Author(s):  
Flavia Debiagi ◽  
Renata K.T. Kobayashi ◽  
Gerson Nakazato ◽  
Luciano Aparecido Panagio ◽  
Suzana Mali
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Aspergillus Niger ◽  
Essential Oils ◽  
Bacillus Cereus ◽  
Streptococcus Mutans ◽  
Enterococcus Faecalis ◽  
Foodborne Pathogens ◽  
Penicillium Citrinum

A preferência mundial para alimentos mais saudáveis e livres de aditivos químicos pelos consumidores, associada ao aumento da resistência bacteriana, resultaram na necessidade de medidas alternativas no setor de alimentos. Os óleos correspondem a antimicrobianos naturais e constituem uma classe emergente como substitutos dos produtos químicos sintéticos na conservação de alimentos. O objetivo deste trabalho foi avaliar a atividade antimicrobiana de óleos essenciais de orégano (OEO) e cravo (CEO ) frente a bactérias, fungos e leveduras de importância no setor de alimentos. OEO e CEO foram avaliados in natura (IN) e após processamento térmico (TP) a 120 o C por 5 minutos. Para avaliar a atividade antimicrobiana frente a cada microrganismo empregou-se o método de discodifusão e o teste de microdiluição em caldo (MIC). Tanto o OEO quanto o CEO apresentaram zonas de inibição semelhantes para amostras IN e TP, indicando que a atividade antimicrobiana desses óleos são resistentes a altas temperaturas. Os microrganismos mais sensíveis para ambos os óleos essenciais foram os fungos (Aspergillus niger, Penicillium citrinum e Candida albicans), seguidos por Staphylococcus aureus, Bacillus cereus e Staphylococcus aureus resistente à meticilina (MRSA). Já as cepas Streptococcus mutans e Enterococcus faecalis apresentaram uma maior resistência frente à atividade antimicrobiana dos óleos essenciais. Em geral, os maiores halos de inibição e menores valores de MIC foram obtidos quando empregado o OEO, sugerindo uma maior atividade microbiana do mesmo quando comparado ao CEO

scholarly journals Cefazolin inoculum effect among methicillinsusceptible Staphylococcus aureus isolated from patients with skin infections

2021 ◽  
Vol 23 (2) ◽  
pp. 205-211
Author(s):  
Anastasia N. Vaganova ◽  
S.V. Borisenko ◽  
E.V. Nesterova ◽  
N.N. Trofimova ◽  
I.V. Litvinenko ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Real Time ◽  
Real Time Pcr ◽  
Disk Diffusion ◽  
Skin Infections ◽  
Beta Lactamase ◽  
Broth Microdilution ◽  
Diffusion Test ◽  
Disk Diffusion Test ◽  
Inoculum Effect

Objective. To evaluate frequency and intensity of cefazolin inoculum effect among methicillin-susceptible staphylococci isolated from patients with skin infections. Materials and Methods. A total of 80 methicillin susceptible isolates of Staphylococcus aureus were identified by cefoxitin disk-diffusion test and negative results of real-time PCR for mecA gene. Inoculum effect was measured by broth microdilution test with two inocula with concentrations of 5 × 105 CFU/mL and 5 × 107 CFU/mL. The disk-diffusion test with cefoxitin was also performed. Penicillin susceptibility was determined by disk-diffusion method. Beta-lactamase blaZ gene was identified by real-time PCR. Results. The frequency of cefazolin inoculum effect in tested isolates was 30% which is consistent with data from different countries. The MIC values for concentrated inoculum reached CLSI breakpoint for cefazolin resistance in 2.5% of isolates. The isolates with inoculum effect and those without it had the similar MIC values for cefazolin in broth microdilution test for standard inocula and similar diameters of inhibition zone in disk-diffusion test with cefazolin. Penicillin resistance was more frequent in inoculum effect-positive isolates. Beta-lactamase activity is considered as a main cause of cefazolin inoculum effect in staphylococci. The beta-lactamase blaZ gene was identified in the majority of isolates with cefazolin inoculum effect, but it was also prevalent among inoculum effect-negative isolates. Conclusions. Up to 30% of MSSA isolates from skin lesions in dermatological patients from SaintPetersburg are positive for cefazolin inoculum effect. Those isolates are usually characterized by penicillin resistance. Most of the cefazolin inoculum effect-positive isolates also carry beta-lactamase blaZ gene.

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