The antibacterial effect of AgNPs was investigated by determining MIC/MBC and growth kinetics assay. The lowest MIC/MBC was found to be in the range of 11.25-22.5 µg ml(-1) . The growth kinetics curve shows that 25 µg ml(-1) AgNPs strongly inhibits the bacterial growth. Confocal laser scanning electron microscopy (CLSM) shows that as the concentration of NPs increases, reduction in the number of cells was observed and at 50 µg ml(-1) of NPs, 100% death was noticed. Scanning electron microscopy (SEM) shows cells were severely damaged with pits, multiple depressions, and indentation on cell surface and original rod shape has swollen into bigger size. High resolution-transmission electron microscopic (HR-TEM) micrograph shows that cells were severely ruptured. The damaged cells showed either localized or complete separation of the cell membrane. The NPs that anchor onto cell surface and penetrating the cells may cause membrane damage, which could result in cell lysis. The interaction of AgNPs to membrane biomolecules; lipopolysaccharide (LPS) and L-α-phosphatidyl-ethanolamine (PE) were investigated by attenuated total reflectance-fourier transform infrared (ATR-FTIR) spectroscopy. LPS and PE showed IR spectral changes after AgNPs exposure. The O-antigen part of LPS was responsible for interaction of NPs through hydrogen bonding. The phosphodiester bond of PE was broken by AgNPs, forming phosphate monoesters and resulting in the highly disordered alkyl chain. The AgNPs-induced structural changes in phospholipid may lead to the loss of amphiphilic properties, destruction of the membrane and cell leaking. The biomolecular changes in bacterial cell envelope revealed by ATR-FTIR provide a deeper understanding of cytotoxicity of AgNPs.

The ability of bacteria to develop antibiotic resistance and colonize abiotic surfaces by forming biofilms is a major cause of medical implant-associated infections and results in prolonged hospitalization periods and patient mortality. Different approaches have been used for preventing biofilm-related infections in health care settings. Many of these methods have their own demerits that include chemical-based complications; emergent antibiotic-resistant strains, and so on. Silver nanoparticles (AgNPs) are renowned for their influential antimicrobial activity. We demonstrate the biofilm formation by extended spectrum b-lactamases-producing Escherichia coli and Klebsiella spp. by direct visualization applying tissue culture plate, tube, and Congo red agar methods. Double fluorescent staining for confocal laser scanning microscopy (CLSM) consisted of propidium iodide staining to detect bacterial cells and concanavalin A-fluorescein isothiocyanate staining to detect the exopolysaccharides matrix were used. Scanning electron microscopy observations clearly indicate that AgNPs reduced the surface coverage by E. coli and Klebsiella spp. thus prevent the biofilm formations. Double-staining technique using CLSM provides the visual evidence that AgNPs arrested the bacterial growth and prevent the exopolysaccharides formation. The AgNPs-coated surfaces effectively restricted biofilm formation of the tested bacteria. In our study, we could demonstrate the complete antibiofilm activity AgNPs at a concentration as low as 50 lg/ml. Our findings suggested that AgNPs can be exploited towards the development of potential antibacterial coatings for various biomedical and environmental applications. These formulations can be used for the treatment of drug-resistant bacterial infections caused by biofilms, at much lower nanosilver loading with higher efficiency.

Poor growth with underweight for age, decreased length/height for age, and underweight-for-height are all relatively common in children with CHD. The underlying causes of this failure to thrive may be multifactorial, including innate growth potential, severity of cardiac disease, increased energy requirements, decreased nutritional intake, malabsorption, and poor utilisation of absorbed nutrition. These factors are particularly common and severe in low-and middle-income countries.Although nutrition should be carefully assessed in all patients, failure of growth is not a contraindication to surgical repair, and patients should receive surgical repair where indicated as soon as possible.Close attention should be paid to nutritional support -primarily enteral feeding, with particular use of breast milk in infancy -in the perioperative period and in the paediatric ICU. This nutritional support requires specific attention and allocation of resources, including appropriately skilled personnel.Thereafter, it is essential to monitor growth and development and to identify causes for failure to catch-up or grow appropriately.

BackgroundPhotodynamic therapy (PDT) has been found to be effective in inhibiting biofilm producing organisms. We investigated the photodynamic effect of gold nanoparticle (GNP) conjugated photosensitizers against Candida albicans biofilm. We also examined the photodynamic efficacy of photosensitizer (PS) conjugated GNPs (GNP-PS) to treat skin and oral C. albicans infection in BALB/c mice.MethodsThe biomimetically synthesized GNPs were conjugated to photosensitizers viz. methylene blue (MB) or toluidine blue O (TB). The conjugation of PSs with GNPs was characterized by spectroscopic and microscopic techniques. The efficacy of gold nanoparticle conjugates against C. albicans biofilm was demonstrated by XTT assay and microscopic studies. The therapeutic efficacy of the combination of the GNP conjugates against cutaneous C. albicans infection was examined in mouse model by enumerating residual fungal burden and histopathological studies.ResultsThe GNP-PS conjugate based PDT was found to effectively kill both C. albicans planktonic cells and biofilm populating hyphal forms. The mixture of GNPs conjugated to two different PSs significantly depleted the hyphal C. albicans burden against superficial skin and oral C. albicans infection in mice.ConclusionThe GNP-PS conjugate combination exhibits synergism in photodynamic inactivation of C. albicans. The GNP conjugate based PDT can be employed effectively in treatment of cutaneous C. albicans infections in model animals. The antibiofilm potential of PDT therapy can also be exploited in depletion of C. albicans on medical appliances such as implants and catheters etc.

Clinical isolates (n = 55) of Pseudomonas aeruginosa were screened for the extended spectrum β-lactamases and metallo-β-lactamases activities and biofilm forming capability. The aim of the study was to demonstrate the antibiofilm efficacy of gum arabic capped-silver nanoparticles (GA-AgNPs) against the multi-drug resistant (MDR) biofilm forming P. aeruginosa. The GA-AgNPs were characterized by UV-spectroscopy, X-ray diffraction, and high resolution-transmission electron microscopy analysis. The isolates were screened for their biofilm forming ability, using the Congo red agar, tube method and tissue culture plate assays. The biofilm forming ability was further validated and its inhibition by GA-AgNPs was demonstrated by performing the scanning electron microscopy (SEM) and confocal laser scanning microscopy. SEM analysis of GA-AgNPs treated bacteria revealed severely deformed and damaged cells. Double fluorescent staining with propidium iodide and concanavalin A-fluorescein isothiocyanate concurrently detected the bacterial cells and exopolysaccharides (EPS) matrix. The CLSM results exhibited the GA-AgNPs concentration dependent inhibition of bacterial growth and EPS matrix of the biofilm colonizers on the surface of plastic catheters. Treatment of catheters with GA-AgNPs at 50 µg ml(-1) has resulted in 95% inhibition of bacterial colonization. This study elucidated the significance of GA-AgNPs, as the next generation antimicrobials, in protection against the biofilm mediated infections caused by MDR P. aeruginosa. It is suggested that application of GA-AgNPs, as a surface coating material for dispensing antibacterial attributes to surgical implants and implements, could be a viable approach for controlling MDR pathogens after adequate validations in clinical settings.

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BackgroundCisplatin is an effective anticancer drug that elicits many side effects mainly due to induction of oxidative and nitrosative stresses during prolonged chemotherapy. The severity of these side effects consequently restricts its clinical use under long term treatment. Riboflavin is an essential vitamin used in various metabolic redox reactions in the form of flavin adenine dinucleotide and flavin mononucleotide. Besides, it has excellent photosensitizing property that can be used to ameliorate these toxicities in mice under photodynamic therapy.Methods and FindingsRiboflavin, cisplatin and their combinations were given to the separate groups of mice under photoilluminated condition under specific treatment regime. Their kidney and liver were excised for comet assay and histopathological studies. Furthermore, Fourier Transform Infrared Spectroscopy of riboflavin-cisplatin combination in vitro was also conducted to investigate any possible interaction between the two compounds. Their comet assay and histopathological examination revealed that riboflavin in combination with cisplatin was able to protect the tissues from cisplatin induced toxicities and damages. Moreover, Fourier Transform Infrared Spectroscopy analysis of the combination indicated a strong molecular interaction among their constituent groups that may be assigned for the protective effect of the combination in the treated animals.ConclusionInclusion of riboflavin diminishes cisplatin induced toxicities which may possibly make the cisplatin-riboflavin combination, an effective treatment strategy under chemoradiotherapy in pronouncing its antineoplastic activity and sensitivity towards the cancer cells as compared to cisplatin alone.

Potassium bromate (KBrO3) is widely used as a food additive and is a major water disinfection by-product. It induces multiple organ toxicity in humans and experimental animals and is a probable human carcinogen. The present study reports the protective effect of dietary antioxidant taurine on KBrO3-induced damage to the rat intestine. Animals were randomly divided into four groups: control, KBrO3 alone, taurine alone and taurine+ KBrO3. Administration of KBrO3 alone led to decrease in the activities of intestinal brush border membrane enzymes while those of antioxidant defence and carbohydrate metabolism were also severely altered. There was increase in DNA damage and DNA-protein cross-linking. Treatment with taurine, prior to administration of KBrO3, resulted in significant attenuation in all these parameters but the administration of taurine alone had no effect. Histological studies supported these biochemical results showing extensive intestinal damage in KBrO3-treated animals and greatly reduced tissue injury in the taurine+ KBrO3 group. These results show that taurine ameliorates bromate induced tissue toxicity and oxidative damage by improving the antioxidant defence, tissue integrity and energy metabolism. Taurine can, therefore, be potentially used as a therapeutic/protective agent against toxicity of KBrO3 and related compounds.