No abstract

The in vitro callus induction of Solanum incanum L. was executed on MS medium supplemented with different concentrations of auxin and cytokinin utilizing petioles and explants of leaves. The highest significant fresh weights from petioles and leaf explants were 4.68 and 5.13 g/jar for the medium supplemented with1.0 mg L−1 BA and 1.0 mg L−1 2,4-D. The callus extract of the leaves was used for the green synthesis of silver nanoparticles (Ag-NPs). Analytical methods used for Ag-NPs characterization were UV-vis spectroscopy, Fourier Transform Infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and Transmission Electron Microscopy (TEM). Spherical, crystallographic Ag-NPs with sizes ranging from 15 to 60nm were successfully formed. The FT-IR spectra exhibited the role of the metabolites involved in callus extract in reducing and capping Ag-NPs. The biological activities of Ag-NPs were dose-dependent. The MIC value for Staphylococcus aureus, Bacillus subtilis, and Escherichia coli was 12.5 µg mL−1, while it was 6.25 µg mL−1 for Klebsiella pneumoniae, Pseudomonas aeruginosa, and Candida albicans. The highest inhibition of phytopathogenic fungi Alternaria alternata, Fusarium oxysporum, Aspergillus niger, and Pythium ultimum was 76.3 ± 3.7, 88.9 ± 4.1, 67.8 ± 2.1, and 76.4 ± 1.0%, respectively at 200 µg mL−1. Moreover, green synthesized Ag-NPs showed cytotoxic efficacy against cancerous cell lines HepG2, MCF-7 and normal Vero cell line with IC50 values of 21.76 ± 0.56, 50.19 ± 1.71, and 129.9 ± 0.94 µg mL−1, respectively.

Background and Aim Recently, the extensive use of quinolones led to increased resistance to these antimicrobial agents, with different rates according to the organism and the geographical region. The aim of this study was to detect the resistance rate of Klebsiella pneumoniae Iraqi isolates toward quinolone antimicrobial agents, to determine genetic mutations in gyrA and parC , to screen for efflux-pump activity, and to screen the presence of plasmid-mediated quinolone resistance (PMQR) genes. Methods Forty-three K. pneumoniae isolates were confirmed phenotypically and genotypically by Vitek 2 system and species specific primers by PCR using the targeting rpo gene followed by sequencing. Antibiotic susceptibility test was carried out using disc diffusion method. Quinolone resistant isolates were subjected to ciprofloxacin MIC testing, and cartwheel method to screen for efflux pump activity. The presence of the plasmid mediated quinolone resistance genes qepA, qnrB, qnrS , and aac(6)Ib was tested by PCR. Sequencing of gyr A and par C was performed. Results We observed a high rate of resistance to ceftriaxone, gentamicin ciprofloxacin, and levofloxacin. Low rate of resistance was detected against amikacin and azithromycin. Ciprofloxacin MIC results revealed that 96.1% of the isolates had MICs >256 µg/mL, 83.4% had MICs >512 µg/mL while 34.6% had MIC >1024 µg/mL. Testing of isolates against ciprofloxacin mixed with EtBr at various concentrations resulted in decreased resistant. Sequencing results showed that Ser83Leu was the most common mutation in gyr A that was observed in all quinolone resistant isolates, followed by Asp87Asn. Ser80Ile mutation in par C was observed in 77.7% of the tested isolates. The prevalence of PMQR genes was 92.5% aac (6)-Ib , 51.8% qnr B, 40.7% qep A, and 37% qnr S. Conclusion Quinolone resistance is common in K. pneumoniae isolates in Baghdad. The frequent mutation in gyr A and par C, and the presence of PMQR genes is alarming.

AIM: This study investigated the antibacterial efficacy of five plant extracts, as well as the combinations of the two most effective plant, extracts either with or without commercial varnish (MI varnish) on the in vitro growth of Streptococcus mutans and Lactobacillus acidophilus in comparison to MI varnish using agar disk diffusion and broth dilution methods. METHODS: Methanolic extractions of five plants (Cinnamon, Turmeric, Ginger, Clove and Black seed,) were tested against the growth of the two oral pathogens. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined for the two most effective extracts, and their combinations with different ratios were evaluated against the growth of the two oral pathogens, followed by incorporating the two effective plants or each into commercial MI varnish to be assessed against the oral pathogens in comparison to MI varnish. RESULTS: Only Cinnamon and Clove produced inhibition zones against Streptococcus mutans and Lactobacillus acidophilus growth. MIC for the two plants showed equal antimicrobial activity against Streptococcus mutans, while Cinnamon had a higher sensitivity to Lactobacillus acidophilus than Clove. A mixture of Cinnamon and Clove in a ratio 1:2 exhibited the highest antibacterial activity. Integration the mixture of both plants into MI varnish in a ratio of 1:1:1 presented the highest antibacterial activity. Meanwhile, the lowest one was recorded for the MI varnish alone. CONCLUSION: Methanolic extract of Cinnamon and Clove has considerable antimicrobial activity against Streptococcus mutans and Lactobacillus acidophilus and a new tool for minimally invasive and adhesive dentistry avenues.