Abstract: The aim of the study was to investigate phytochemical
properties, antimicrobial activity and cytotoxicity of Aloe vera. The
phytochemical screening of the extracts of leaves of A. vera revealed
the presence of bioactive compounds such as alkaloids, tannins,
flavonoids phenolic compounds, and etc. with absence of cyanogenic
glycosides. Three different solvents such as methanol, ethanol and
Di-Methyl sulfoxide were used to screen the antimicrobial activity of
A. vera leaves against four human clinical pathogens by agar well
diffusion method. The maximum antibacterial activities were
observed in methanol extract followed by ethanol and Di-Methyl
sulfoxide. It was also found that remarkable antibacterial activities
with methanolic and ethanolic extracts of A. vera compared with the
standard antibiotic, tetracycline that was not active against E. coli
and S. boydii and supported the view that A. vera is a potent
antimicrobial agent compared with the conventional antibiotic.
Moreover, the brine shrimps (Artemia salina) toxicity test exhibited
LC50 value was 569.52 ppm. The resulting data indicated that the A.
vera plant have less toxic effects on brine shrimp. Hence, it is
signified that Aloe vera plant extract is safe to be used as an
antimicrobial agent.
Abstract: Proteins levels produced by bacteria may be increased
in stressful surroundings, such as in the presence of antibiotics. It
appears that many antimicrobial agents or antibiotics, when used at
low concentrations, have in common the ability to activate or repress
gene transcription, which is distinct from their inhibitory effect.
There have been comparatively few studies on the potential of
antibiotics or natural compounds in nature as a specific chemical
signal that can trigger a variety of biological functions. Therefore,
this study was focusing on the effect of essential oils from
Cymbopogon flexuosus and C. nardus in regulating proteins
production by Bacillus subtilis ATCC 21332. The Minimum
Inhibition Concentrations (MICs) of both essential oils on B. subtilis
were determined by using microdilution assay, resulting 0.2% and
1.56% for each C. flexuosus and C. nardus subsequently. The
bacteria were further exposed to each essential oils at concentration
of 0.01XMIC for 2 days. The proteins were then isolated and
analyzed by sodium dodecyl sulfate polyacrylamide gel
electrophoresis (SDS-PAGE). Protein profile showed that a band
with approximate size of 250 kD was appeared for the treated
bacteria with essential oils. Thus, Bacillus subtilis ATCC 21332 in
stressful condition with the presence of essential oils at low
concentration could induce the protein production.
Abstract: Carbon nanotubes (CNTs) are attractive because of
their excellent chemical durability mechanical strength and electrical
properties. Therefore there is interest in CNTs for not only electrical
and mechanical application, but also biological and medical
application.
In this study, the dispersion power of surfactant-treated multiwalled
carbon nanotubes (MWCNTs) and their effect on the antibacterial
activity were examined. Surfactant was used sodium
dodecyl-benzenesulfonate (SDBS). UV-vis absorbance and
transmission electron microscopy(TEM) were used to characterize the
dispersion of MWCNTs in the aqueous phase, showing that the
surfactant molecules had been adsorbed onto the MWCNTs surface.
The surfactant-treated MWCNTs exhibited antimicrobial activities
to streptococcus mutans. The optical density growth curves and viable
cell number determined by the plating method suggested that the
antimicrobial activity of surfactant-treated MWCNTs was both
concentration and treatment time-dependent.
Abstract: This study was set to determine the antimicrobial
activities of brine salting, chlorinated solution, and oil frying
treatments on enteric bacteria and fungi in Rastrineobola argentea
fish from fish landing beaches within L. Victoria basin of western
Kenya. Statistical differences in effectiveness of the different
treatment methods was determined by single factor ANOVA, and
paired two-tail t-Test was performed to compare the differences in
moisture contents before and after storage. Oil fried fish recorded the
lowest microbial loads, sodium chloride at 10% concentration was
the second most effective and chlorinated solution even at 150ppm
was the least effective against the bacteria and fungi in fish. Moisture
contents of the control and treated fish were significantly lower after
storage. These results show that oil frying of fish should be adopted
for processing and preserving Rastrineobola argentea which is the
most abundant and affordable fish species from Lake Victoria.
Abstract: A series of 1-(1H-benzimidazol-2-yl)-3-(substituted phenyl)-2-propen-1-one were allowed to react with hydrazine hydrate and phenyl hydrazine in submitted reactions to get pyrazoline and phenyl pyrazoline derivatives. All the compounds entered for screening at the Tuberculosis Antimicrobial Acquisition and Coordinating Facility (TAACF) for their in vitro antibacterial activity against Mycobacterium tuberculosis H37Rv strain (ATCC 27294) using Microplate Alamar Blue Assay (MABA) susceptibility test. The results expressed as MIC (minimum inhibitory concentration) in μg/mL. Among the fifteen compounds, eight compounds were found to have MIC values less than 10 μg/mL. These were subjected for cytotoxicity assay in VERO cells to determine CC50 (cytotoxic concentration 50%) values and finally SI (Selectivity Index) were calculated. Compound (XV) 2-[5-(4- fluorophenyl)-1-phenyl-4,5-dihydro-1H-3-pyrazolyl]-1Hbenzimidazole was considered the best candidate of the series that could be a good starting point to develop new lead compounds in the fight against tuberculosis.
Abstract: The increasing usage of antibiotics in the animal
farming industry is an emerging worldwide problem contributing to
the development of antibiotic resistance. The purpose of this work was
to investigate the prevalence and antibiotic resistance profile of
bacterial isolates collected from aquatic environments and meats in a
peri-urban community in Daejeon, Korea. In an antibacterial
susceptibility test, the bacterial isolates showed a high incidence of
resistance (~ 26.04 %) to cefazolin, tetracycline, gentamycin,
norfloxacin, erythromycin and vancomycin. The results from a test for
multiple antibiotic resistance indicated that the isolates were
displaying an approximately 5-fold increase in the incidence of
multiple antibiotic resistance to combinations of two different
antibiotics compared to combinations of three or more antibiotics.
Most of the isolates showed multi-antibiotic resistance, and the
resistance patterns were similar among the sampling groups.
Sequencing data analysis of 16S rRNA showed that most of the
resistant isolates appeared to be dominated by the classes
Betaproteobacteria and Gammaproteobacteria in the phylum
Proteobacteria.
Abstract: Antimicrobial resistant is becoming a major factor in
virtually all hospital acquired infection may soon untreatable is a
serious public health problem. These concerns have led to major
research effort to discover alternative strategies for the treatment of
bacterial infection. Nanobiotehnology is an upcoming and fast
developing field with potential application for human welfare. An
important area of nanotechnology for development of reliable and
environmental friendly process for synthesis of nanoscale particles
through biological systems In the present studies are reported on the
use of fungal strain Aspergillus species for the extracellular synthesis
of bionanoparticles from 1 mM silver nitrate (AgNO3) solution. The
report would be focused on the synthesis of metallic bionanoparticles
of silver using a reduction of aqueous Ag+ ion with the
culture supernatants of Microorganisms. The bio-reduction of the
Ag+ ions in the solution would be monitored in the aqueous
component and the spectrum of the solution would measure through
UV-visible spectrophotometer The bionanoscale particles were
further characterized by Atomic Force Microscopy (AFM), Fourier
Transform Infrared Spectroscopy (FTIR) and Thin layer
chromatography. The synthesized bionanoscale particle showed a
maximum absorption at 385 nm in the visible region. Atomic Force
Microscopy investigation of silver bionanoparticles identified that
they ranged in the size of 250 nm - 680 nm; the work analyzed the
antimicrobial efficacy of the silver bionanoparticles against various
multi drug resistant clinical isolates. The present Study would be
emphasizing on the applicability to synthesize the metallic
nanostructures and to understand the biochemical and molecular
mechanism of nanoparticles formation by the cell filtrate in order to
achieve better control over size and polydispersity of the
nanoparticles. This would help to develop nanomedicine against
various multi drug resistant human pathogens.
Abstract: Commercial nanocomposite food packaging type nano-silver containers were characterised using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The presence of nanoparticles consistent with the incorporation of 1% nano-silver (Ag) and 0.1% titanium dioxide (TiO2) nanoparticle into polymeric materials formed into food containers was confirmed. Both nanomaterials used in this type of packaging appear to be embedded in a layered configuration within the bulk polymer. The dimensions of the incorporated nanoparticles were investigated using X-ray diffraction (XRD) and determined by calculation using the Scherrer Formula; these were consistent with Ag and TiO2 nanoparticles in the size range 20-70nm both were spherical shape nanoparticles. Antimicrobial assessment of the nanocomposite container has also been performed and the results confirm the antimicrobial activity of Ag and TiO2 nanoparticles in food packaging containers. Migration assessments were performed in a wide range of food matrices to determine the migration of nanoparticles from the packages. The analysis was based upon the relevant European safety Directives and involved the application of inductively coupled plasma mass spectrometry (ICP-MS) to identify the range of migration risk. The data pertain to insignificance levels of migration of Ag and TiO2 nanoparticles into the selected food matrices.
Abstract: Lectins have a good scope in current clinical
microbiology research. In the present study evaluated the
antimicrobial activities of a D-galactose binding lectin (PnL) was
purified from the annelid, Perinereis nuntia (polychaeta) by affinity
chromatography. The molecular mass of the lectin was determined to
be 32 kDa as a single polypeptide by SDS-PAGE under both reducing
and non-reducing conditions. The hemagglutinating activity of the
PnL showed against trypsinized and glutaraldehyde-fixed human
erythrocytes was specifically inhibited by D-Gal, GalNAc,
Galβ1-4Glc and Galα1-6Glc. PnL was evaluated for in vitro
antibacterial screening studies against 11 gram-positive and
gram-negative microorganisms. From the screening results, it was
revealed that PnL exhibited significant antibacterial activity against
gram-positive bacteria. Bacillus megaterium showed the highest
growth inhibition by the lectin (250 μg/disc). However, PnL did not
inhibit the growth of gram-negative bacteria such as Vibrio cholerae
and Pseudomonas sp. PnL was also examined for in vitro antifungal
activity against six fungal phytopathogens. PnL (100 μg/mL) inhibited
the mycelial growth of Alternaria alternata (24.4%). These results
indicate that future findings of lectin applications obtained from
annelids may be of importance to life sciences.
Abstract: The present study has been taken to explore the
screening of in vitro antimicrobial activities of D-galactose-binding
sponge lectin (HOL-30). HOL-30 was purified from the marine
demosponge Halichondria okadai by affinity chromatography. The
molecular mass of the lectin was determined to be 30 kDa with a
single polypeptide by SDS-PAGE under non-reducing and reducing
conditions. HOL-30 agglutinated trypsinized and glutaraldehydefixed
rabbit and human erythrocytes with preference for type O
erythrocytes. The lectin was subjected to evaluation for inhibition of
microbial growth by the disc diffusion method against eleven human
pathogenic gram-positive and gram-negative bacteria. The lectin
exhibited strong antibacterial activity against gram-positive bacteria,
such as Bacillus megaterium and Bacillus subtilis. However, it did
not affect against gram-negative bacteria such as Salmonella typhi
and Escherichia coli. The largest zone of inhibition was recorded of
Bacillus megaterium (12 in diameter) and Bacillus subtilis (10 mm in
diameter) at a concentration of the lectin (250 μg/disc). On the other
hand, the antifungal activity of the lectin was investigated against six
phytopathogenic fungi based on food poisoning technique. The lectin
has shown maximum inhibition (22.83%) of mycelial growth of
Botrydiplodia theobromae at a concentration of 100 μg/mL media.
These findings indicate that the lectin may be of importance to
clinical microbiology and have therapeutic applications.
Abstract: Multidrug resistant organisms have been taunting the
medical world for the last few decades. Even with new antibiotics
developed, resistant strains have emerged soon after. With the
advancement of nanotechnology, we investigated colloidal silver
nanoparticles for its antimicrobial activity against Pseudomonas
aeruginosa. This organism is a multidrug resistant which contributes
to the high morbidity and mortality in immunocompromised patients.
Five multidrug resistant strains were used in this study. The
antimicrobial effect was studied using the disc diffusion and broth
dilution techniques. An inhibition zone of 11 mm was observed with
10 μg dose of the nanoparticles. The nanoparticles exhibited MIC of
50 μg/ml when added at the lag phase and the subinhibitory
concentration was measured as 100 μg/ml. The MIC50 value showed
to be 15 μg/ml. This study suggests that silver nanoparticles can be
further developed as an antimicrobial agent, hence decreasing the
burden of the multidrug resistance phenomena.
Abstract: The present research was designed to investigate the
anti-microbial activity of aristolochic acid from the root of
Aristolochia bracteata. From the methanolic & ethyl extract extracts
of Aristolochia bracteata aristolochic acid I was isolated and
conformed through IR, NMR & MS. The percentage purity of
aristolochic acid I was determined by UV & HPLC method. Antibacterial
activity of extracts of Aristolochia bracteata and the
isolated compound was determined by disc diffusion method. The
results reveled that the isolated aristolochic acid from methanolic
extract was more pure than the compound from ethyl acetate extract.
The various extracts (500μg/disc) of Aristolochia bracteata showed
moderate antibacterial activity with the average zone of inhibition of
7-18 mm by disc diffusion method. Among the extracts, ethyl acetate
& methanol extracts were shown good anti-microbial activity and the
growth of E.coli (18 mm) was strongly inhibited. Microbial assay of
isolated compound (Aristolochic acid I) from ethyl acetate &
methanol extracts were shown good antimicrobial activity and the
zone of inhibition of both at higher concentration 50 μg/ml was
similar with the standard aristolochic acid. It may be concluded that
the isolated compound of aristolochic acid I has good anti-bacterial
activity.
Abstract: A new composite sorbent based on carbonized rice
husk (CRH) and immobilized on it living cells and inactivated
cultural liquid containing antimicrobials metabolites of Bacillus
subtilis CK-245 is developed. The sorption and antimicrobic activity
of CRH concerning five species of Enterobacteriaceae is studied.
Prospects of use of developed sorbent in medicine and veterinary
science is shown.