A sustainable green-approach for biofabrication of chitosan nanoparticles, optimization, characterization, its antifungal activity against phytopathogenic Fusarium culmorum and antitumor activity.

Chitosan is a natural non-toxic, biocompatible, biodegradable, and mucoadhesive polymer. It also has a broad spectrum of applications such as agriculture, medical fields, cosmetics and food industries. In this investigation, chitosan nanoparticles were produced by an aqueous extract of Cympopogon citratus leaves as a reducing agent. According to the SEM and TEM micrographs, CNPs had a spherical shape, and size ranging from 8.08 to 12.01 nm. CNPs have a positively charged surface with a Zeta potential of + 26 mV. The crystalline feature of CNPs is determined by X-ray diffraction. There are many functional groups, including C꞊C, CH2-OH, C-O, C-S, N-H, CN, CH and OH were detected by FTIR analysis. As shown by the thermogravimetric study, CNPs have a high thermal stability. For the optimization of the green synthesis of CNPs, a Face centered central composite design (FCCCD) with 30 trials was used. The maximum yield of CNPs (13.99 mg CNPs/mL) was produced with chitosan concentration 1.5%, pH 4.5 at 40 °C, and incubation period of 30 min. The antifungal activity of CNPs was evaluated against phytopathogenic fungus; Fusarium culmorum. A 100% rate of mycelial growth inhibition was gained by the application of 20 mg CNPs/mL. The antitumor activity of the green synthesized CNPs was examined using 6 different cell lines, the viability of the cells reduced when the concentration of green synthesized CNPs increased, the IC50 dose of the green synthesized CNPs on the examined cell lines HePG-2, MCF-7, HCT-116, PC-3, Hela and WI-38 was 36.25 ± 2.3, 31.21 ± 2.2, 67.45 ± 3.5, 56.30 ± 3.3, 44.62 ± 2.6 and 74.90 ± 3.8; respectively.

Bacterial nanocellulose production using Cantaloupe juice, statistical optimization and characterization.

The bacterial nanocellulose has been used in a wide range of biomedical applications including carriers for drug delivery, blood vessels, artificial skin and wound dressing. The total of ten morphologically different bacterial strains were screened for their potential to produce bacterial nanocellulose (BNC). Among these isolates, Bacillus sp. strain SEE-3 exhibited potent ability to produce the bacterial nanocellulose. The crystallinity, particle size and morphology of the purified biosynthesized nanocellulose were characterized. The cellulose nanofibers possess a negatively charged surface of - 14.7 mV. The SEM images of the bacterial nanocellulose confirms the formation of fiber-shaped particles with diameters of 20.12‒47.36 nm. The TEM images show needle-shaped particles with diameters of 30‒40 nm and lengths of 560‒1400 nm. X-ray diffraction show that the obtained bacterial nanocellulose has crystallinity degree value of 79.58%. FTIR spectra revealed the characteristic bands of the cellulose crystalline structure. The thermogravimetric analysis revealed high thermal stability. Optimization of the bacterial nanocellulose production was achieved using Plackett-Burman and face centered central composite designs. Using the desirability function, the optimum conditions for maximum bacterial nanocellulose production was determined theoretically and verified experimentally. Maximum BNC production (20.31 g/L) by Bacillus sp. strain SEE-3 was obtained using medium volume; 100 mL/250 mL conical flask, inoculum size; 5%, v/v, citric acid; 1.5 g/L, yeast extract; 5 g/L, temperature; 37 °C, Na2HPO4; 3 g/L, an initial pH level of 5, Cantaloupe juice concentration of 81.27 percent and peptone 11.22 g/L.

Exploration of a novel and efficient source for production of bacterial nanocellulose, bioprocess optimization and characterization.

The demand for bacterial nanocellulose is expected to rise in the coming years due to its wide usability in many applications. Hence, there is a continuing need to screen soil samples from various sources to isolate a strain with a high capacity for bacterial nanocellulose production. Bacillus sp. strain SEE-12, which was isolated from a soil sample collected from Barhiem, Menoufia governorate, Egypt, displayed high BNC production under submerged fermentation. Bacillus sp. strain SEE-12 was identified as Bacillus tequilensis strain SEE-12. In static cultures, BNC was obtained as a layer grown in the air liquid interface of the fermentation medium. The response surface methodology was used to optimise the process parameters. The highest BNC production (22.8 g/L) was obtained using 5 g/L peptone, 5 g/L yeast extract, 50%, v/v Cantaloupe juice, 5 g/L Na2HPO4, 1.5 g/L citric acid, pH 5, medium volume of 100 mL/250 mL conical flask, inoculum size 5%, v/v, temperature 37 °C and incubation time 6 days. The BNC was purified and characterized by scanning electron microscopy (SEM), Energy-dispersive X-ray (EDX) spectroscopy, differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and transmission electron microscopy (TEM).

Green synthesis of chitosan nanoparticles, optimization, characterization and antibacterial efficacy against multi drug resistant biofilm-forming Acinetobacter baumannii.

Chitosan nanoparticles (CNPs) are promising versatile cationic polymeric nanoparticles, which have received growing interest over last few decades. The biocompatibility, biodegradability, environmental safety and non-toxicity of the chitosan nanoparticles makes it preferred for a wide range of biological applications including agriculture, medical and pharmaceutical fields. In this study, CNPs were biosynthesized by aqueous extract of Eucalyptus globulus Labill fresh leaves as bio-reductant. Box-Behnken design in 29 experimental runs was used for optimization of different factors affecting the production of CNPs. The maximum yield of CNPs was 9.91 mg/mL at pH of 4.5, chitosan concentration of 1%, incubation time of 60 min and temperature of 50 °C. The crystallinity, particle size and morphology of the biosynthesized CNPs were characterized. The CNPs possess a positively charged surface of 31.1 mV. The SEM images of the CNPs confirms the formation of spherical form with smooth surface. The TEM images show CNPs were spherical in shape and their size range was between 6.92 and 10.10 nm. X-ray diffraction indicates the high degree of CNPs crystallinity. FTIR analysis revealed various functional groups of organic compounds including NH, NH2, C-H, C-O, C-N, O-H, C-C, C-OH and C-O-C. The thermogravimetric analysis results revealed that CNPs are thermally stable. The antibacterial activity of CNPs was determined against pathogenic multidrug-resistant bacteria, Acinetobacter baumannii. The diameters of the inhibition zones were 12, 16 and 30 mm using the concentrations of 12.5, 25 and 50 mg/mL; respectively. When compared to previous studies, the biosynthesized CNPs produced using an aqueous extract of fresh Eucalyptus globulus Labill leaves have the smallest particle sizes (with a size range between 6.92 and 10.10 nm). Consequently, it is a promising candidate for a diverse range of medical applications and pharmaceutical industries.

Virulence Determinants and Antimicrobial Profiles of Pasteurella multocida Isolated from Cattle and Humans in Egypt.

Pasteurella multocida is a Gram-negative bacterium that causes drastic infections in cattle and humans. In this study, 55 isolates were recovered from 115 nasal swabs from apparently healthy and diseased cattle and humans in Minufiya and Qalyubia, Egypt. These isolates were confirmed by kmt1 existence, and molecular classification of the capsular types showed that types B, D, and E represented 23/55 (41.8%), 21/55 (38.1%), and 11/55 (20.0%), respectively. The isolates were screened for five virulence genes with hgbA, hgbB, and ptfA detected in 28/55 (50.9%), 30/55 (54.5%), and 25/55 (45.5%), respectively. We detected 17 capsular and virulence gene combinations with a discriminatory power (DI) of 0.9286; the most prevalent profiles were dcbF type D and dcbF type D, hgbA, hgbB, and ptfA, which represented 8/55 (14.5%) each. These strains exhibited high ranges of multiple antimicrobial resistance indices; the lowest resistances were against chloramphenicol, ciprofloxacin, amoxicillin/clavulanic acid, and levofloxacin. The macrolide-lincosamide-streptogramin B methylase gene erm(Q), with erm(42) encoding MLSB monomethyltransferase, mph(E) encoding a macrolide efflux pump, and msr(E) encoding macrolide-inactivating phosphotransferase were present. The class 1 and 2 integrons and extended-spectrum ß-lactamase genes intl1, intl2, blaCTX-M, blaCTX-M-1, and blaTEM were detected. It is obvious to state that co-occurrence of resistance genes resulted in multiple drug-resistant phenotypes. The identified isolates were virulent, genetically diverse, and resistant to antimicrobials, highlighting the potential risk to livestock and humans.

Comparative study between zinc oxide nanoparticles synthesis by biogenic and wet chemical methods in vivo and in vitro against Staphylococcus aureus.

ZnO nanoparticles (ZnO-NPs) can be used as nano medicine for Staphylococcus aureus infection, which causes deleterious effects on liver, kidney and lung tissue, as it causes catarrhal bronchitis, peri-bronchial oedema, lymphocytic granulomas, oedematous fluid and haemorrhage inside the bronchi, and interstitial pneumonia. In this research ZnO nanoparticle (ZnO-NPs) synthesis by biogenic method using green alga Ulva fasciata and by wet chemical method. Both of them tested in vitro and in vivo against Staphylococcus aureus. The characterization of ZnO-NPs was detected by U.V spectroscopy, Fourier-transform infrared (FTIR), Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). In vivo assessment eight groups, each group contain of five rats and the treatment as follow (1) an uninfected control group; (2) an infected group; groups (3), (4), and (5) were injected with biogenic or chemical ZnO-NPs or zinc acetate, as the bulk group, respectively; and groups (6), (7) and (8) were infected and then treated in the same manner as groups (3), (4), and (5), respectively. The blood profile, biochemical parameters, phagocytic activity and histological assessment of liver, kidney and lung tissue of each rat was investigated after 20 days. The rats treated with 5 mg/1 kg natural ZnO-NPs showed improved lung characteristics, and the number of platelets in the infected groups treated with ZnO-NPs from chemical and natural sources (G6 and G7) was close to those in the control group. However, the trend was reversed for regarding lymphocytes, which remained at higher levels in uninfected animals treated with synthetic ZnO-NPs (G4) than in infected rats treated with synthetic ZnO-NPs (G7). Moreover, a significant difference in phagocytic activity was found among all groups compared to that of controls. Compared to control group rats (G1), uninfected rats injected with only natural ZnO-NPs (G3) showed a significant (P < 0.05) improvement in the phagocytic index. We propose that ZnO-NPs produced from natural sources are preferable to those produced from chemical sources for use as nano medicine for the treatment of S. aureus infection in albino rats.