16 research outputs found
Fecal carriage and phylodiversity of communityacquired bla TEM Enteric bacilli in Southwest Nigeria
Purpose: Increasing rates of clonal spread of fecal blaTEM bacilli remains a huge concern to the community health with resultant high morbidity. The fecal carriage and clonal diversity of blaTEM within the communities in Southwest Nigeria were surveyed.
Materials and methods: Enteric bacilli obtained from fresh fecal samples randomly collected
from community residents were biotyped and profiled for antibiotic susceptibility. Resistant
strains were typed for beta-lactamase, extended-spectrum beta-lactamases (ESBL), AmpC and
carbapenemase production while the R-plasmid carriage was detected and mating activities were
examined. The presence of blaTEM gene was assayed by PCR and its phylodiversity determined
with 16sRNA genomic profiling.
Results: Escherichia coli have the highest (28.6%) occurrence rate and Pseudomonas aeruginosa
(20.5%) showing significant resistance to beta-lactamase inhibitors (ampicillin, cefuroxime and
cefotaxime), and high-level multidrug resistance of more than 15.2% rate to ampicillin, cefuroxime, ceftazidime, tetracycline and imipenem. E. coli and Klebsiella oxytoca, are the highest
beta-lactamase, ESBL and AmpC producers encoded with high molecular weight R-plasmid
(>11.0 kbp) and significant rate of conjugation and transformational activities. Only 2/14, 1/13
and 1/6 ESBL-type of E. coli, K. oxytoca and Enterobacter cloaca, expressed blaTEM gene, clustering into five different phylodiverse groups with close genomic relatedness with other bacilli.
Conclusion: This is an indication of clonal dissemination of ESBL blaTEM encoded enteric
bacilli having high phylodiverse characteristics through fecal carriage in the Nigerian community which requires public health education, food and environmental hygiene for its preventio
IN-VITRO ANTIBACTERIAL, PHYTOCHEMICAL, ANTIMYCOBACTERIAL ACTIVITIES AND GC-MS ANALYSES OF Bidens pilosa LEAF EXTRACT.
The phytochemical constituents, antimicrobial activity, anti-mycobacterial activity and gas chromatography-mass spectrometry (GCMS) analysis of the West African ecotype of Bidens pilosa was investigated for possible medicinal properties. The antimicrobial activity of the hexane, dichloromethane, ethyl acetate and methanol extracts from the leaf of Bidens pilosa was evaluated using agar dilution method. The qualitative and quantitative phytochemical screening was carried out according to standard procedures. Partitioned fractions of the methanolic extract was subjected to anti-mycobacterial bioassay. Different fractions of the leaf were subjected to GCMS to ascertain the compounds present. The antimicrobial analysis revealed the methanolic fraction as having the highest number of activity against test organisms such as: Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Candida albicans and Rhizopus sp. between 10 - 40 mm. The minimum inhibitory concentration showed the methanolic fraction to be active against Candida albicans and Rhizopus sp. at the concentration of 6.25 g/ml and 3.25 g/ml respectively. The phytochemical screening revealed the presence of alkaloids, cardiac glycosides and terpenoids in all the solvents. Tannin was present in all the solvent fractions except hexane fraction. Saponin was not found in any of the solvents. The hexane-methanol interface of the partitioned solvents was sensitive to the anti-mycobacterial activity while other solvents showed resistance. The GC-MS and the chromatogram gave insight into the volatile components of the leaf extract. The findings reveals Bidens pilosa as a medicinal plant with potentials for the treatment of tuberculosis.
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Multi-antibiotics Resistant Relatedness of bla-gene Encoded Enteric Bacteria harbouring High Molecular R-plasmids.
Increase prevalence of multi-resistant enteric bacteria isolates encoded with high mobile R-plasmid
causing enteric infections was examined among the community residents in Abeokuta, Nigeria.
Random cluster sampling of 251 fecal samples of community residents were cultured for enteric
bacteria and biotyped. Disc diffusion and Micro-broth dilution assay were used to determine antibiotic
susceptibility while R-plasmid was profiled with photo-gel documentation. Antibiotic resistance
relatedness was detected using DendroUPGMA construction utility software. Of all isolates obtained,
31.3% were Escherichia coli Klebsiella oxytoca (19.5%), Pseudomonas aeruginosa (15.3%) and
Shigella specie (2.0%). Significant high rate of 62.6% showed resistant to Cefuroxime, 61.6% to
Ampicillin and Augmentin (54.2%) while 44.7%, 38.9% and 33.9% resist Cotrimoxazole,
Ciprofloxacin and Tetracycline respectively at MIC >16 μg/ml (p= 0.004). Only 54.1% harboured
high molecular weight R-plasmid (>11.0kbp) and 2.7% having <5kbp R-plasmid weight. Two distinct
clusters revealed significant multi-antibiotic resistant relatedness. Cluster A enteric isolates harboured
similar R-plasmid of only one bands with high molecular weight more than 11kbp while Cluster B
divided into subgroup a and subgroup b comprising different enteric species having similar high
molecular weights with high antibiotic resistant expressing more than two plasmid bands showing
computed cophenetic correlation of 0.94. Cluster analysis reveal a related high level multi-antibiotics
resistant enteric bacteria strains among the community residents suggesting a continuous
dissemination and imminent outbreak of resistant enteric pathotypes with resultant epidemic
proportion
Synthesis of low toxic silver-cobalt nanoparticles using Annona muricata leaf extract: Antimicrobial evaluation
In a bid for green chemistry, a sustainable approach using Annona muricata aqueous extract was engaged as a reducing agent to synthesise bimetallic silver-cobalt nanoparticles (Ag-Co NPS). Hot extraction using distilled water was done on the locally sourced plant (leaf part). It was then screened for biomolecules present as geographical location affects phytochemical compositions. Phytoreduction reaction with nanoparticle formation rate was monitored with a UV–Vis spectrophotometer. Then, further characterisations were achieved by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), Fourier-transform infrared (FTIR), and X-ray diffraction (XRD). The average particle size of 39.34 nm 9.21 nm was obtained. This study shows an interesting result, as the increase in Ag-Co NPs concentration did not significantly affect the flies’ survival compared to the control. At P < 0.05, similar behaviour was observed in the locomotive assay of the model used. An antibacterial agent can also be developed, as revealed in the antimicrobial assay on Staphylococcus aureus (ATCC25923), Streptococcus pneumoniae, Escherichia coli (ATCC 25922), Klebsiella sp., and Salmonella sp. and a fungus strain: Candida albicans
Modeling and Synthesis of Ag and Ag/Ni Allied Bimetallic Nanoparticles by Green Method: Optical and Biological Properties
In the quest for environmental remediation which involves eco-friendly synthetic routes, we herein report synthesis and modeling
of silver nanoparticles (Ag NPs) and silver/nickel allied bimetallic nanoparticles (Ag/Ni NPs) using plant-extract reductionmethod.
Secondary metabolites in the leaf extract of Canna indica acted as reducing agent. Electronic transitions resulted in emergence of
surface plasmon resonance in the regions of 416 nm (Ag NPs) and 421nm (Ag/Ni NPs) during optical measurements. Further
characterizations were done using TEM and EDX. Antimicrobial activity of the nanoparticles against clinical isolates was highly
significant a
Geospatial Investigation of Nigerian Honey and Detection of Anti-Enteric Biomarker
Geospatial mapping and antibacterial biomarkers were investigated in Nigerian honey used for therapeutic purposes in several
communities affected with prevalent antibiotic-resistant enteric bacilli. Randomly collected enteric bacilli from faecal samples
were biotyped and phenotypically assayed for antibiotic resistance and profiled for R plasmids. R plasmid molecular weight and
multiantibiotic resistance index (MARI) relatedness were evaluated for resistance among phylogroups. Honey cidal activity, time
kill kinetics, and bioactive markers were determined and analysed for geospatial distribution. More than 30% enteric biotypes
were resistant to cotrimoxazole, ciprofloxacin, and tetracycline at MIC ≥16 μg/ml (P � 0.004). Two unrelated cluster complexes
with diverse antibiotic resistance indices expressed high molecular weight plasmid (14.17 kbp) with 0.73 MARI to two classes of
antibiotics. Among the resistant bacilli, only 24.3% (MIC90 500 mg/mL) and 8.1% (MBC90 1000 mg/mL) were susceptible to honey
with evidence of 14.85% and 5.94% significant viable reduction at 2 × MIC to less than 2.50 Log10 CFU/mL (P < 0.05). Only
alkaloids significantly regressed (P � 0.028) with susceptibility of resistant bacilli significantly correlate with bacteria inhibition
(r � 0.534, P � 0.049) at optimal cutoff limit of 0.32 mg/ml. Antibacterial honey with significant alkaloid biomarkers was detected
at 3°10′0–3°30′0E and 6°30′0–7°30′0N of Southwest Nigeria. Spatial mapping evidently indicated variation in honey physicochemical
and bioactive compounds and identified geographical locations suitable for production of anti-enteric honey rich in
alkaloids marker required for prevention and treatment of resistant enteric bacilli infections
Phytochemical Screening and Antimicrobial Studies of Stem and Root Extracts of Crateva adansonii
Aim: This study was designed to explore the phytochemical and antimicrobial screening of the
stem and root extracts of Crateva adansonii.
Place and Duration of Study: Sample: Iyesi village, Ota, Ogun State, and analysis carried out at
Department of Chemistry and Department of Biological Sciences, Covenant University, Ota, Ogun
State and for duration of three months (November 2016 to February 2017).
Methodology: Standard universal procedures were employed for both phytochemical and
antimicrobial analysis.
Results: The result obtained from the stem and root extracts of Crateva adansonii indicated the
presence of flavonoids, terpenoids, alkaloids, and cardiac glycosides. Root extract was found to be
richer in source of phytochemicals when compared to the stem extract. However, the highest antibacterial activity was observed against selected bacteria by both stem and root extracts. The
potency of the root extract was observed to be higher than the stem extract against Bacillus cereus,
Staphylococcus aureus, Aspergillus niger and Serratia spp.
Conclusion: The preliminary studies on the stem and the root of Crateva adansonii extracts
revealed their antimicrobial potential which could be further investigated for global utilization in
pharmaceutical treatment, natural therapies, food preservation and cosmetic applications
Synthesis of low toxic silver-cobalt nanoparticles using Annona muricata leaf extract: Antimicrobial evaluation
In a bid for green chemistry, a sustainable approach using Annona muricata aqueous extract was engaged as a reducing agent to synthesise bimetallic silver-cobalt nanoparticles (Ag-Co NPS). Hot extraction using distilled water was done on the locally sourced plant (leaf part). It was then screened for biomolecules present as geographical location affects phytochemical compositions. Phytoreduction reaction with nanoparticle formation rate was monitored with a UV–Vis spectrophotometer. Then, further characterisations were achieved by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), Fourier-transform infrared (FTIR), and X-ray diffraction (XRD). The average particle size of 39.34 nm ± 9.21 nm was obtained. This study
shows an interesting result, as the increase in Ag-Co NPs concentration did not significantly affect the flies’
survival compared to the control. At P < 0.05, similar behaviour was observed in the locomotive assay of the
model used. An antibacterial agent can also be developed, as revealed in the antimicrobial assay on Staphylococcus aureus (ATCC25923), Streptococcus pneumoniae, Escherichia coli (ATCC 25922), Klebsiella sp., and Salmonella sp. and a fungus strain: Candida albicans
Anti-mycobacterial and GC-MS Studies of Irvingia gabonensis Baill Ex. Lanen Stem Extracts
Irvingia gabonensis baill ex. lanen (Bush mango) is an ethno-medicinal plant that has
been used for traditional therapeutic purposes. With the increasing rate of drug
resistance to various diseases in the society today, there is the need for alternative
sources of drugs for the treatment of such disease. The Bush mango plant presents a
potential candidate for such drugs discovery. Extracts from the plant stem were derived
by cold maceration separately in methanol (MeOH) and Dichloromethane (DCM) for
a period of 7 days. Phyto-constituents were also identified in extracts of stems by using
hyphenated mass spectrometer and chromatographic technique, the Gas
Chromatography - Mass Spectrometer (GC/MS) while the functional group of such
phyto-constituents were identified with the aid of Nicolet 5700 Fourier Transform–
Infra-Red spectrometer. Anti-tubercular screening was performed on extracts against
clinically isolated drug-susceptible strains (DS-MTB-1 - DS-MTB-5), drug resistant
strains (DR-MTB-1, DR-MTB-2) and a standard tubercular strain, H37Rv. This was
controlled with drug standards, rifampicin and levofloxacin. Extracts revealed the
presence of phyto-constituents such as saponins, tannin, alkaloids and phenol. It was
observed that both extracts recorded high % alkaloid content at 10.37±0.02. Also,
identified by FTIR as the principal part of the extracts are hydrocarbon groups such as
carboxylic acid (1042), while the presence of the volatile components such as 9-
Oxabicyclo [6.1.0] nonane (C8H14O) and 1-Chlorobutatriene (C4H3C) were reported by
GC-MS. Extracts exhibited significant anti-tubercular activity against all organisms.
Therefore, this study promotes the use of Irvingia gabonensis baill ex. lanen for phytotherapeutics
purposes
Infection Control of Spatial Disseminated Multi-Antibiotics Resistant And Phylo- Diverse Staphylococcus Aureus Pathotypes
Focal dissemination of multi-antibiotic resistant (MAR) Staphylococci pathotypes
regulated by agr functionalities was investigated and evaluated for infection control.
Non-repetitive Staphylococcus aureus strains from soft and skin infections disseminated
in several communities were recovered and biotyped, assayed for biofilm and profiled for
antibiotic resistance. Strains were further genotyped for spa types, virulence and
resistant genes; and mapped for geospatial distribution. Clonal diversity and functional
accessory gene regulators ( agr ) were also evaluated. Staphylococcal infection was not
significant with age group (p>0.05), but high rate of MSSA (53.0%) and MRSA (1.5%)
was observed. Median resistance rates were significantly differ (p=0.001) but highest 75
th percentile and media resistance rates were observed in wound infection. Resistance
rate of 78.8% at MIC 50 32μg/ml and MIC 90 128μg/ml to amoxicillin-clavulanate, and
more than 40% resistance to ceftazidime, ciprofloxacin, gentamycin, ofloxacin,
sulfamethoxazole and tetracycline with MIC 90 and MIC 50 at 32 μg/ml were observed.
More than 0.83 multi-antibiotic resistance index (MARI) were observed among the
strains that clustered into separate phylo-group expressing high beta- lactamase and
strong biofilm production. Heterogeneous spa types t442 (wound and pus), t657
(wound), t091 (ear) and t657 (ear and wound) revealed high phylo- diversity. Only 4.6%
pvl + MSSA-CC1 agr I, pvl + MSSA-CC5 (13.6%) and pvl + MRSA-CC7 agr II (4.6%),
expressed enterotoxin; sea, sec, sed, sej, Leukocidins ( LukF-PV, lukD, lukE ),
proteases ( aur, slpA sspB, sspE ) and resistance genes ( fosB, msr (A), bla
mph(C),aphA3, sat, fosB, sdrM, Q7A4X2) . Phylogenetic related spa types of livestock
origin, specifically bovine milk clustered with detected strains that were prevalent in
urban communities with focal dissemination to other nearest suburbs. Clonal
dissemination resistant pvl+ MAR MSSA-CC1 and MRSA- CC5 encoding agr were
predominant in several peri-urban communities. This require adequate genosurveillance,
population-target antimicrobial stewardship, extensive community health
care intervention policy and well-structured infection control programs to prevent further
focal dissemination