Staphylococcus aureus atcc 25923

The antimicrobial activity of the AgHA, AgHA-C, and AgHA-T suspensions and tetracycline and ciprofloxacin were investigated in vitro using the reference Staphylococcus aureus ATCC 25923 (ATCC, Old Town Manassas, VA, USA), Escherichia coli ATCC 25922 (ATCC, Old Town Manassas, VA, USA), and Candida albicans ATCC 10231 (ATCC, Old Town Manassas, VA, USA) microbial strains. The antimicrobial assays were done according to a methodology previously reported in [69 (link),70 (link),71 (link),72 (link)], with 0.5 McFarland standard microbial cultures. Afterward, the samples were inoculated using 1.5 mL microbial suspension of a density of 5 × 10⁶ CFU/mL (colony forming units/mL), prepared in phosphate-buffered saline (PBS), and incubated for 24, 48, and 72 h, respectively. As a positive control (C+), free microbial culture was assessed at the same time intervals. Afterward, the suspension was collected at different time intervals (24, 48, and 72 h) and incubated on a LB agar medium for 24 h at 37 °C. The number of CFU/mL was determined for each of the incubated samples with the microbial suspensions. The values of the CFU/mL were determined. The experiments were performed three times and the data were presented as mean ± SD. The statistical analysis was performed using the ANOVA single-factor test.

The natural specimens consisting of 100 mg of Bangkhuntien's mangrove forest soil, Nam Nao National Park's soil, and Yaowarat Chinese market herbs were mixed with sterile distilled water to final volume of 10 mL. For Rayong's seawater, 10 mL was collected and diluted 1,000 times with NSS before use. After homogenization, 100 µL of the aqueous solutions was plated on agar plate of CDA, MEA, MRS, NA, PCA, PDA, SDA, and TSA (Difco, USA). We incubated the plate 3 days and then transferred single colony into new NA agar plate. During doing bacteria culture, bacterial Gram of all strains was identified by standard Gram staining. In this study, we used 4 importance human pathogens as standards for antibacterial assay, namely, Bacillus cereus ATCC14579, Escherichia coli ATCC25922, Pseudomonas aeruginosa ATCC27853, and Staphylococcus aureus ATCC25923 (ATCC, USA). In order to maintain all the isolated and standard bacterial strains, we kept their 3-day NB cultures with 25% glycerol and restocked them every 6 months at −80°C. All bacteria strains' genomic DNA was prepared using Presto™ Mini gDNA Bacteria Kit following the manufacturer protocol (Geneaid, Taiwan).

Medium molecular weight CS, degree of deacetylation~75% (molecular weight: 100,000–300,000 g/mol), and PVA, 13,000–23,000 g/mol, 87–89% degree of hydrolysis were purchased from Acros Organics BVBA (Geel, Belgium). Glutaraldehyde (GA) 50% in aqueous solution, anhydrous ≥98.0% magnesium sulfate (MgSO₄), and glycerine ≥99.7% were purchased from VWR International. Zinc oxide nanopowder (ZnO, 99+%, 10–30 nm) was obtained from US Research Nanomaterials, Inc. (Houston, TX, USA). Human dermal fibroblasts cell line (HDFa), Dulbeco’s modified Eagle’s Medium (DMEM), 10% fetal bovine serum (FBS), antibiotics (streptomycin/penicillin), non-essential amino acids, phosphate-buffered saline (PBS), and trypsin-EDTA, necessary for in vitro cytotoxicity assay, were purchased from Thermo Fisher Scientific (Waltham, MA, USA). 3-(4,5-Dimethyl-2-thia zolyl)-2,5-diphenyl-2H-tetrazolium bromide was obtained from Merck Millipore (Darmstadt, Germany). Freeze-dried stains (Staphylococcus aureus-ATCC 25923, Escherichia coli-ATCC 11775, Klebsiella pneumonia-ATCC BAA–1705, and Pseudomonas aeruginosa-ATCC 10145) were purchased from ATCC (Manassas, VA, USA). Chapman agar (mannitol salt agar) was purchased from Oxoid (Hampshire, United Kingdom) and MacConkey agar from G & M Procter Ltd. (Perth, UK). All other chemicals used were of analytical grade.

Micrococcus luteus (an environmental isolate) was a kind gift from Prof. Charles Greenblatt from the Hebrew university in Jerusalem, Israel. An inoculum was grown in Luria-Bertani (LB) medium at 30 °C with 220 rpm shaking overnight. Staphylococcus hominis (ATTC 27844) and Staphylococcus aureus (ATCC 25923) were purchased from ATCC, USA. An inoculum was grown in brain-heart infusion (BHI) media at 37 °C with 220 rpm shaking overnight.

Staphylococcus aureus ATCC 25923 (ATCC: American Type Culture Collection), S. aureus ST1065 (kindly provided by Tarek Msadek, Institut Pasteur Paris, France), multidrug-resistant S. aureus ATCC 43300 and ATCC BAA-44 (ATCC), Enterococcus faecalis ATCC 29212 (ATCC), Bacillus megaterium (laboratory collection), Escherichia coli ATCC 25922, E. coli ML-35p, Salmonella enterica serotype Enteritidis (kindly provided by Sylvie Rebuffat, Muséum National d'Histoire Naturelle, Paris, France), Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 13883, and Acinetobacter baumannii ATCC 19606 (ATCC) were incubated in lysogeny broth (LB, Sigma-Aldrich) for 2–3 h at 37°C to obtain a mid-logarithmic phase culture. Listeria ivanovii Li4pVS2 (kindly provided by Jean-Marc Berjeaud, Université de Poitiers, France), and Streptococcus pyogenes ATCC 19615 (ATCC) were cultured in brain heart infusion (BHI, Sigma-Aldrich) medium under the same conditions.

CMC, glycerol (GLY), AMK, NaOH, HCl, penicillin, streptomycin, Mueller–Hinton (MH) agar, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) solution, PBS tablets, silica gel beads, and transdermal diffusion membranes were obtained from Millipore Sigma (St. Louis, MO, US) and used without any modification. The human fetal lung fibroblast cells (MRC-5) (ATCC CCL-171) and bacterial strains (Escherichia coli (ATCC 8739), Pseudomonas aeruginosa (ATCC 9027), and Staphylococcus aureus (ATCC 25923)) were procured from the American Type Culture Collection (ATCC, Manassas, VI, USA). The culture medium RPM1-1640 and fetal bovine serum (FBS) were obtained from Nacalai Tesque (Kyoto, Japan) and Biosera (Nuaille, France), respectively. All experiments were performed in double-distilled water (DDW) unless otherwise specified. AX was extracted and characterized from Plantago ovata/psyllium seed husk (PSH) using our previously described method [12 (link),29 (link)].