Rotula aquatica Lour. mitigates oxidative stress and inflammation in acute pyelonephritic rats.

The current study evaluates the efficacy of methanolic extract of Rotula aquatica Lour. (MERA) against inflammatory changes associated with acute pyelonephritis. The antioxidant enzymes such as SOD, CAT, GPx, GR and oxidative stress markers like GSH content, malondialdehyde (MDA) level, nitrate level, reactive oxygen species (ROS) level and renal toxicity markers were evaluated in this study. The mRNA level expression of Toll-like receptor 4 (TLR-4), nuclear transcription factor kappa B (NF-κB), tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and Tamm Horsfall protein (THP) were studied by RT-PCR analysis. The oral administration of MERA increases the antioxidant enzyme status in pyelonephritis rat. The elevated levels of oxidative stress markers in pyelonephritic rats were ameliorated by the administration of MERA at 100 mg/kg and 200 mg/kg bwt of the rat. The mRNA level expression of major genes were restored to normal level by MERA.

Advantage of zinc oxide nanoparticles over silver nanoparticles for the management of Aeromonas veronii infection in Xiphophorus hellerii.

Bacterial pathogens cause significant challenge to the ornamental fish industry. Eventhough antibiotic administration has been recommended to manage fish diseases, there is alarming concern with emergence of antibiotic resistance. This indicates the need for the development of alternative methods with multi-targeted action to manage fish diseases. In the study, silver (AgNPs) and zinc oxide (ZnONPs) nanoparticles have been evaluated for its activity against Aeromonas veronii. Both the AgNPs and ZnONPs were found to have bactericidal activity against A. veronii. In vivo experiments with A. veronii was found to cause severe mortality in Xiphophorus hellerii with a LD50 of 1.4 × 108 CFU/mL. However, treatment with AgNPs and ZnONPs each at a concentration of 1 mg/L was found to enhance the survival rate of X. hellerii to 83.3% and 100% respectively. Further histopathological analysis showed alterations in gill, intestine and liver of X. hellerii due to A. veronii in the infection control. In the case of AgNPs treated group, symptoms of moderate tissue damage could be observed. However, the ZnONPs treated X. hellerii showed normal histological features with minimum tissue damage. The bath dip method further confirmed the protective ability of the zinc oxide nanoparticles (1 mg/L) on X. hellerii.

A potential antifungal and growth-promoting bacterium Bacillus sp. KTMA4 from tomato rhizosphere.

Plant growth-promoting rhizobacteria are indigenous beneficial bacteria that will enhance plant growth as well as suppress phytopathogens. In the present study, the isolate KTMA4 showed the highest inhibition against major phytopathogens of tomato; Fusarium oxysporum (66%) and Alternaria solani (54%) after seven days of incubation. Analysis of the 16S rRNA gene sequence revealed that the isolate KTMA4 is Bacillus cereus (MG547975). The isolate produced in vitro plants growth-promoting factors such as Indole-3-acetic acid, ammonia, catalase, siderophore and 1-aminocyclopropane-1-carboxylate deaminase and it has nitrogen fixation ability. The bacterial strain has also produced lytic enzymes such as amylase, cellulase, xylanase, lipase, and protease. Moreover, the bacterium Bacillus cereus KTMA4 effectively produced biofilm, biosurfactants and salt-tolerant (5% NaCl). The bacterium exhibited intrinsic antibiotic resistance. The in vivo studies using tomato plants grown from seeds treated with the bacterial strain KTMA4 demonstrated an enhancement in seed germination percentage (86.66 ± 2.88) and vigour index (637.5 ± 21.65) over the uninoculated control (germination percentage- 28.33 ± 2.88 and vigour index- 42.5 ± 4.33). 60 days of greenhouse study revealed that the bacterial isolate enhanced the plant growth significantly (P ≤ 0.05) compared to the uninoculated control and the treated plants. Therefore the study suggests that the newly isolated rhizosphere bacterial strain can be used as a potential biocontrol agent against a multitude of fungal pathogens as well as a biofertilizer inoculant for tomato cultivation.

Surface functionalization of central venous catheter with mycofabricated silver nanoparticles and its antibiofilm activity on multidrug resistant Acinetobacter baumannii.

The mycofabrication of silver nanoparticles (AgNPs) through green chemistry protocol is an advanced methodological progress in medical nanotechnology. Mycofabricated AgNPs are less toxic due to an aura of biomolecules around the nanoparticles. Hence the mycofabricated AgNPs can be used for clinical applications. The present study explores the antibiofilm activity of mycogenerated AgNPs, which were synthesized by the enzymatic reduction of silver nitrate using the marine algicolous endophytic fungus Penicillium polonicum ARA10. The mycogenerated AgNPs showed very specific and potent bactericidal activity against Acinetobacter baumannii. Anti-A.baumannii activities of mycogenerated AgNPs on planktonic as well as biofilm embedded cells were explored. The physical impact of synthesized AgNPs on A.baumannii was investigated by scanning electron microscopy and fluorescence microscopy. A bionanocomposite coating for the central venous catheter (CVC) was formulated using the mycogenerated AgNPs and polydopamine. The bionanocomposite surface was characterized by field emission scanning electron microscopy, water contact angle measurement, and Raman spectroscopy. The results showed that the mycogenerated AgNPs have potent antibiofilm activity on biofilms of A.baumannii. The scanning electron microscopy (SEM) and fluorescence microscopy images showed noticeable aberrations on the ultrastructure of A.baumannii. The SEM and FE-SEM images of biofilms on the surface of CVC samples proved that the AgNPs at minimum bactericidal concentration could destroy the structure of biofilms and lyses the bacterial cell. Thus, the present study establishes a new way to the development of 'antibacterial surfaces' based on mycogenerated AgNPs.

Protective effect of Rotula aquatica Lour against gentamicin induced oxidative stress and nephrotoxicity in Wistar rats.

Gentamicin is an aminoglycoside antibiotic widely used for the treatment of life-threatening infections caused by Gram-negative bacteria. The use of gentamicin was limited due to its ototoxic and nephrotoxic adverse effects. The current study was designed to evaluate the protective effect of ethyl acetate fraction from Rotula aquatica (EFRA) against gentamicin induced nephrotoxicity. The antioxidant enzymes status, lipid peroxidation, nitrate and ROS level, serum markers like creatinine, Urea, BUN were estimated in the present study. The histopathological analysis of renal tissues was done by H&E and PAS staining. The mRNA level expression of KIM-1, NF-κB, TNF- α, and IL-6 were measured by semi-quantitative reverse transcription-polymerase chain reaction. The changes in antioxidant parameters were restored by the treatment of EFRA at different dose (50 mg/kg bwt, 100 mg/kg bwt). The serum parameters, ROS, MDA and nitrate level were decreased by administration of EFRA. The EFRA ameliorates histological changes associated with gentamicin induced nephrotoxicity. The mRNA level expression of KIM-1, NF-κB, TNF- α, and IL-6 were downregulated in EFRA treated groups. The results from present study reveals the role of EFRA as good anti-inflammatory and nephro protective drug.

Studies on biofilm formation and virulence factors associated with uropathogenic Escherichia coli isolated from patient with acute pyelonephritis.

The current study aims to the detection of pathogenic potential and virulence factor identification of uropathogenic Escherichia coli BRL-17 isolated from patients urine. The organism was isolated from the patient with chronic pyelonephritis. The identification of organism was done by analyzing gram staining, biochemical, 16S rDNA analysis, Raman microscopy and SEM analysis. The pathogenic potential was identified by multiplex PCR analysis of virulence factor genes like sfa, hly D, pap C. The biofilm forming ability was tested by congo red agar assay and tissue culture plate assay. The result of gram staining and biochemical analysis shows the characteristics of E-coli. The 16S rDNA analysis of the clinically isolated uropathogen showed 100% similarity with uropathogenic Escherichia coli strain. Raman microscopy and SEM confirms the organism as E-coli. The Multiplex PCR study identifies virulence genes like sfa, hly D, pap C in isolated E-coli. The presence of P fimbriae coded pap C gene, S fimbriae coded sfa gene and hemolysin-D coded hly D gene discloses its potential to cause urinary tract infection. Biofilm assay result enhances the organism's role as strong biofilm former. This biofilm forming ability of Escherichia coli strain BRL-17 made the organism to escape from host immune system and helps to colonize in bladder and kidney. This also helps to enhance the resistance to antibiotics. Our study confirms the organism as multidrug resistant, highly virulent, strong biofilm forming E-coli. The strain may be used for the development of animal models of pyelonephritis for the purpose of drug discovery.

Efficient visible light induced synthesis of silver nanoparticles by Penicillium polonicum ARA 10 isolated from Chetomorpha antennina and its antibacterial efficacy against Salmonella enterica serovar Typhimurium.

The green synthesis of silver nanoparticles (AgNPs) using biological systems such as fungi has evolved to become an important area of nanobiotechnology. Herein, we report for the first time the light-induced extracellular synthesis of silver nanoparticles using algicolous endophytic fungus Penicillium polonicum ARA 10, isolated from the marine green alga Chetomorpha antennina. Parametric optimization, including the concentration of AgNO3, fungal biomass, ratio of cell filtrate and AgNO3, pH, reaction time and presence of light, was done for rapid AgNPs production. The obtained silver nanoparticles (AgNPs) were characterized by UV-Visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and Transmission electron microscopy (HRTEM-EDAX). The AgNPs showed a characteristic UV-visible peak at 430 nm with an average size of 10-15 nm. The NH stretches in FTIR indicate the presence of protein molecules. The Raman vibrational bands suggest that the molecules responsible for the reduction and stability of AgNPs were extracellular proteins produced by P.polonicum. Antibacterial evaluation of AgNPs against the major foodborne bacterial pathogen Salmonella enterica serovar Typhimurium MTCC 1251, was assessed by well diffusion, Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assay. Killing kinetic studies revealed complete killing of the bacterial cells within 4 h and the bactericidal nature of synthesized nanoparticles was confirmed by fluorescent microscopy and scanning electron microscopy. Furthermore, the bactericidal studies with Transmission electron microscopy (TEM) at different time intervals explored the presence of AgNPs in the cell wall of S.Typhimurium at about 30 min and the complete bacterial lysis was found at 24 h. The current research opens an insight into the green synthesis of AgNPs and the mechanism of bacterial lysis by direct damage to the cell wall.

Green synthesized silver nanoparticles by marine endophytic fungus Penicillium polonicum and its antibacterial efficacy against biofilm forming, multidrug-resistant Acinetobacter baumanii.

Acinetobacter baumanii, a gram-negative, non-motile, encapsulated coccobacillus which causes infections worldwide. The objective of this study was to find a fungal strain that could be utilized to biosynthesize antibacterial silver nanoparticles (AgNPs) against Acinetobacter baumanii. The present investigation explains rapid and extracellular biosynthesis of silver nanoparticles by the algicolous endophytic fungus, Penicillium polonicum, isolated from the marine green alga Chetomorpha antennina. The obtained silver nanoparticles were characterized by UV-Vis spectroscopy, Raman spectroscopy, Fourier transformation infrared (FTIR), and Transmission electron microscopy (TEM). The SNPs showed a characteristic UV- visible peak at 430 nm with an average size of 10-15 nm. As evident from the FTIR and Raman spectra, possibly the protein components of fungal extract have caused the reduction of silver nitrate. Parametric optimization, including the concentration of AgNO3, ratio of cell filtrate and AgNO3, fungal biomass, reaction time, pH, and presence of light, was done for rapid AgNPs production. The antibacterial efficacy of AgNPs against multi-drug-resistant, biofilm-forming Acinetobacter baumanii, was evaluated by well diffusion assay. The Minimum inhibitory concentration (MIC) of AgNP was 15.62 µgml-1 and the minimum bactericidal concentration (MBC) was 31.24 µgml-1. Killing kinetic assay revealed complete killing of the bacterial cells within 6 h. Log reduction and percent survival of bacterial cells were analyzed from killing kinetic study. Bactericidal nature of synthesized nanoparticles was confirmed by fluorescent microscopical analysis. The effect of AgNPs on the ultrastructure of bacterial pathogen was evaluated by Transmission electron microscopy.