Antibacterial efficacy of chemically and plant-synthesized zinc oxide nanocomposite against Staphylococcus aureus and Escherichia coli inoculated in Tilapia fillet

Aims@#Edible coatings developed from biodegradable materials such as starch and zinc oxide nanoparticles (ZnO-NPS) are efficient antimicrobials that could be used as a food additive to reduce the bacterial load on the food surface. Therefore, this study was aimed to examine the effect of chemical and green synthesized ZnO-NPS with different concentrations on the survival of Escherichia coli and Staphylococcus aureus in fish fillets during chilling storage at 4 ± 1°C.@*Methodology and results@#ZnO-NPS were chemically prepared by mixing zinc acetate dihydrate with sodium hydroxide. Lavandula officinalis was used for the green synthesis of ZnO-NPS. The sterile biodegradable coating containing 2 and 5% of both chemically and green synthesized ZnO-NPS were made using starch, gelatin, xanthan gum and glycerol. Different bacterial cocktail strains of both E. coli and S. aureus were inoculated onto Tilapia fillet samples. The coating solution with different antimicrobials was aseptically spread in Tilapia fillets and examined periodically within two days intervals for the survival of S. aureus and E. coli during chilling at 4 ± 1 °C. Both chemically and plantsynthesized ZnO-NPS reduced the growth of both S. aureus and E. coli by about 3.7 log10 CFU/cm2 of Tilapia fillet. The incorporation of L. officinalis increased the antibacterial activity of ZnO-NPS. Staphylococcus aureus was more sensitive than E. coli for both chemically and plant-synthesized ZnO-NPS. Moreover, zinc oxide biodegradable coating extended the shelf-life of chilled Tilapia fillets by about 4 days.@*Conclusion, significance and impact of study@#The results of the current study demonstrated the incorporation of L. officinalis into ZnO-NPS biodegradable coating which may be promising in reducing microbial growth on food surfaces.

Staphylococcus aureus derived hyaluronic acid and bacillus Calmette-Guérin purified proteins as immune enhancers to rabies vaccine and related immuno-histopathological alterations

Purpose@#One of the essential goals regarding the successful control of rabies infection is the development of a safe, effective, and inexpensive vaccine. the current study aimed to evaluate the inactivation potential of β-propiolactone (βPL), binary ethyleneimine (BEI), and hydrogen peroxide (H2O2). @*Materials and Methods@#Estimating the inactivation kinetics of βPL, BEI, and H2O2 revealed that the tested inactivants could completely and irreversibly inactivate rabies virus within 2, 12, and 4 hours, respectively while maintaining its viral immunogenicity. The potency of βPL, BEI, and H2O2 inactivated vaccines was higher than the World Health Organization acceptance limit and were in the order of 3.75, 4.21, and 3.64 IU/mL, respectively. Monitoring the humoral and cellular immunity elicited post-immunization using Staphylococcus aureus derived hyaluronic acid (HA) and bacillus Calmette-Guérin purified protein derivative (PPD) adjuvanted rabies vaccine candidates were carried out using enzyme-linked immunosorbent assay. @*Results@# @*Results@#demonstrated that both adjuvants could progressively enhance the release of anti-rabies total immunoglobulin G as well as the pro-inflammatory mediators (interferon-gamma and interleukin-5) relative to time. However, a higher immune response was developed in the case of HA adjuvanted rabies vaccine compared to PPD adjuvanted one. The harmful consequences of the tested adjuvants were considered via investigating the histopathological changes in the tissues of the immunized rats using hematoxylin and eosin stain. Lower adverse effects were observed post-vaccination with HA and PPD adjuvanted vaccines compared to that detected following administration of the currently used alum as standard adjuvant. @*Conclusion@#Our findings suggested that HA and PPD could serve as a promising platform for the development of newly adjuvanted rabies vaccines with elevated immune enhancing potentials and lower risk of health hazards.

Evaluation of zinc-oxide nanocoating on the characteristics and antibacterial behavior of nickel-titanium alloy

ABSTRACT Objective: To investigate the effect of ZnO nanocoating on mechanical properties of NiTi orthodontic wires and antibacterial activity. Methods: 0.016 x 0.022-in NiTi orthodontic wires were coated with ZnO nanoparticles using an electrochemical deposition method with three electrodes system in 0.1M Zn(NO3)2. Mechanical properties and frictional resistance of the coated wires were investigated using an universal testing machine. Antibacterial effect of ZnO coating was also investigated. Results: A stable adhered ZnO nanocoating on NiTi wires was obtained. The coated wires have a significant antibacterial activity against S. aureus, S. pyogens and E. coli, and a reduction of frictional forces by 34%. Conclusion: ZnO nanocoating may improve the antibacterial effects of NiTi wires and reduce the frictional resistance. Coating may be implanted in orthodontic practice for faster and safer treatment.

RESUMO Objetivos: Avaliar o efeito do nanorrevestimento de óxido de zinco (ZnO) sobre as propriedades mecânicas e propriedades antibacterianas de fios ortodônticos de NiTi. Métodos: Fios 0,016" x 0,022" de NiTi foram revestidos com nanopartículas de ZnO por meio de um método de deposição eletroquímica com um sistema de três eletrodos a 0,1M Zn(NO3)2. Uma máquina universal de testes foi utilizada para avaliar as propriedades mecânicas e a resistência friccional dos fios revestidos. Além disso, também foram analisadas as propriedades antibacterianas do revestimento de ZnO. Resultados: Obteve-se uma aderência estável das nanopartículas de ZnO sobre os fios NiTi. Os fios revestidos apresentaram atividade antibacteriana significativa contra S. aureus, S. pyogens e E. coli, e apresentaram uma redução de 34% na força de atrito. Conclusão: O revestimento com nanopartículas de óxido de zinco pode melhorar as propriedades antibacterianas e reduzir a resistência friccional dos fios de NiTi. Assim, o revestimento dos fios pode ser utilizado na Ortodontia visando tratamentos mais rápidos e seguros.

Effect of Cyclosporine A on the Kidney of Rabbit: A Light and Ultrastructural Study.

Background: Nephrotoxicity is a relatively common problem in patients immunosuppressed with cyclosporine A (CsA) with an incidence reaching up to thirty percent. The present work aimed to study the histological and ultrastructural effects of CsA on the kidney of rabbit. Materials andMethods: Two groups of Egyptian adult rabbits were used for this study (5 rabbits for each). One group was used as a control and the other group (experimental) was treated with CsA in a dose of 15 mg/kg of body weight for two weeks. The animals were anaesthetized; and kidney specimens were obtained, fixed and processed for light and electron microscopic examinations. Results: CsA had adverse effects on the kidney especially renal corpuscles, proximal convoluted tubules, distal convoluted tubules and afferent glomerular arterioles. The renal corpuscles were observed with shrunken glomeruli, widening of Bowman’s space and thickening of the Bowman’s capsule. Also, there was obvious increase in mesangial cell number and overall glomerular obliteration due to large lining endothelial cells and encroachment of the mesangial cell matrix onto the capillary lumen. The renal tubules showed vacuolization and PAS positive inclusion bodies. The cells showed disordered brush border of microvilli. Many fibrocytes appeared inbetween the tubules. Peritubular capillary congestion was observed with an increase in the surrounding connective tissue. Ultrastructurally, the proximal convoluted tubules showed thick basement membrane with loss of the basal infolding. Themitochondria appeared degenerated with damaged transverse cristae. Electron dense lysosomes were seen in the cytoplasm. In distal convoluted tubules, the cells showed degenerated mitochondria and pyknotic nuclei. The afferent glomerular arterioles appeared with hyperplasia of juxtaglomerular cells that containedmassive renin granules. The lining endothelial cells appeared protruding their nuclei into the lumen due to contraction of the smooth muscles. Conclusions: It could be concluded that CsA had adverse structural changes on the kidneymainly on the nephron; renal corpuscles, proximal convoluted tubules, distal convoluted tubules and afferent glomerular arterioles. Defective renal function should always be a concern in the management of CsA treated patient.

Value of MRI and inflammatory markers in assessment of erosive osteoarthritis hand

To investigate the role of MRI and inflammatory markers [serum C reactive protein [CRP] as a marker of erosive osteoarthritis [EOA] of the hand. Thirty three patients, 22 with EOA and 11 with non-EOA of the hand, were included in the study and analysed for radiographic score [RS], number of erosions, and joint count [JC] at clinical observation and at MRI CRP was assayed in a serum sample by a highly sensitive immunonephelometric method. The median [interquartile range] CRP level was 5.2[2.7-7.2] mg/l in the EOA and 2.8 [0.7-5.2] mg/I in the non-EOA group [p = 0.001]. In all patients, CRP correlated with RS [p<0.001], and mainly with JC at clinical observation [p<0.001] and MRI [p<0.001]. The correlation of CRP with RS and JC was confirmed at clinical observation and at MRI in the EOA subgroup, but only with JC at clinical observation in the non-EOA subgroup. CRP levels are higher in EOA than in non-EoA patients. These levels probably reflect the disease activity of EOA, as suggested by correlations between CRP and JC at clinical observation and MRI. BMI, body mass index; CRP, C reactive protein; EOA, erosive osteoarthritis; ESR, erythrocyte sedimentation rate; hsCRP, high sensitivity CRP; MRI, Magnetic Resonance Imaging; IL, interleukin; JC, joint count; OA, osteoarthritis; RS, radiographic score