Erick N Ondari | Kampala International University dar es salaam (original) (raw)

Papers by Erick N Ondari

Streptococcus suis and Streptococcus parauberis are both contagious organisms devastating the hum... more Streptococcus suis and Streptococcus parauberis are both contagious organisms devastating the humans and the economy as well. The former is responsible for endocarditis, arthritis, pneumonia, septicemia, meningitis and lately has been reported for toxic shock syndrome (STSS) and the latter causes mastitis in cows and streptococcisis in tfish. The current study hypothesized to model structure for DapB gene encoding dihydrodipicolinate reductase enzyme yields diaminopimelate acid and meso-diaminopimelate which are necessary for peptidoglycan as the main component for cell wall in both Gram positive and negative bacteria. Hence, identification of potential inhibitors against DapB could potentially inhibit synthesis of final components making up the cell thus bacterial death. The findings revealed homology structures attained were good with phi/psi angles of 90.1 %, 91.8 % residues fell in the most favored regions respectively for S. parauberis and S. suis. Interaction studies revealed ...

Non-coding functional elements recently have proved to play vital functions in eukaryotes worthy ... more Non-coding functional elements recently have proved to play vital functions in eukaryotes worthy ignoring in the prokaryotic counter parts. We argue that elucidating these non-coding elements will lead to a better understanding of the differences coexisting between the Streptococci species, an important human pathogen responsible for vast diseases devastating the economy. The study analyzed 56 strains from NCBI, where 44,523 sequences were extracted by PERL script. Similarity search by Blast, Genemark and CPC revealed a total of 1443 potential sequences preceding functional studies by deploying Pfam, InterproScan and COG depicting 144 proteins allowing them to be designated as novel ones. The results potentially could be used as new vaccine targets, better understanding of the different biological niches; re-annotation also can be looked unto for potential genomic island identification and further wet-lab extensions research work for better understanding of the Streptococci family f...

ABSTRACT The research illuminates DHFR from Pneumocystis jiroveci as a newly potential drug targe... more ABSTRACT The research illuminates DHFR from Pneumocystis jiroveci as a newly potential drug target against pneumonia. P. jiroveci DHFR sequence Q9UUP5 was obtained from Swiss-Prot database and deployed for 3-dimensional structure prediction. Sequence similarity templates searching found between P.j DHFR against 1CD2, 1VJ3 and 1DR1 paved the modeling with high confidence. The superimposition of the predicted template structures revealed the sequence identity of more than 30% and RMSD values of 4vs.1, 4vs.2, 4vs.3 and 4vs.5 and RMSD values 0.094, 0.093, 0.094 and 0.108 respectively; it comes under the expected range of <2Ȧ. The structure showed overall conservation domains involved in binding affinity, energy minimization value, as well as inter-subunit interactions. Our results provided a basis of structural modeling (threading), energy minimization, RMSD value, structural validation and evaluation, to compare the overall structure and functional amino acids dependent on P.j DHFR in Pneumocystis. Further analysis to show the differences found between the inter and intra species of P.j DHFR is a leeway to design inhibitors targeted specifically against Pneumocystis jiroveci pneumonia (PJP).

Asian Journal of Chemistry, 2021

Mycotoxins like aflatoxins, ochratoxins, patulin, citrinin, deoxynivalenol (DON), fumonisins, tri... more Mycotoxins like aflatoxins, ochratoxins, patulin, citrinin, deoxynivalenol (DON), fumonisins, trichothecenes, etc., produced by molds (Aspergillus avus, A. parasiticus, Penicillin spp, etc.) could occupy such grains as peanuts, millet, sunower, cassava, beans, sesame, sorghum, maize, etc. In order to either eliminate and or reduce the levels of mycotoxins, as well as detection limits, there are a number of grain processing techniques that have been reported in the literature. In this article, an overview of the effectiveness of grain processing methods to eliminate mycotoxins was performed. Specifically, the grain processing techniques considered include: extrusion, alkaline cooking, flaking, roasting, frying, baking, milling, cooking, cold plasma, cleaning, trimming, sorting, as well as chemical treatments like the use of sodium hydroxide, citric acid, sodium bisulfite and ammonia. Overall, while most methods seem effective in reducing some mycotoxins over others, more studies are ...

Resistance emergency has necessitated continuous search for drugs with least toxicity, effective,... more Resistance emergency has necessitated continuous search for drugs with least toxicity, effective, affordable and eco-friendly which possess new mode of action to cater the rising emergency. In this study, T. procumbens was used for biogenic synthesis of silver nanoparticles and investigated for antibacterial and antifungal activity. Characterization was done by UV-Vis spectrum, SEM, XRD, EDAX and FTIR. The UV-vis spectrum max was observed at 452 nm. EDAX AgNPs revealed total yield of 96.7% with 100 % purity, whilst SEM and XRD revealed spherical and elongated shape with an average grain size of 3.973 nm. FTIR examination provided evidence for presence of primary amides, aromatic ketones and aliphatic amines groups that could be responsible for synthesis and stability of the synthesized silver nanoparticles. Bio potential analysis of the synthesized biogenic silver nanoparticles showed antimicrobial activity against the twelve human and fish pathogens tested with 10 mm zone of inhibi...

Foods

Mycotoxins are produced by fungi and are known to be toxic to humans and animals. Common mycotoxi... more Mycotoxins are produced by fungi and are known to be toxic to humans and animals. Common mycotoxins include aflatoxins, ochratoxins, zearalenone, patulin, sterigmatocystin, citrinin, ergot alkaloids, deoxynivalenol, fumonisins, trichothecenes, Alternaria toxins, tremorgenic mycotoxins, fusarins, 3-nitropropionic acid, cyclochlorotine, sporidesmin, etc. These mycotoxins can pose several health risks to both animals and humans, including death. As several mycotoxins simultaneously occur in nature, especially in foods and feeds, the detoxification and/or total removal of mycotoxins remains challenging. Moreover, given that the volume of scientific literature regarding mycotoxins is steadily on the rise, there is need for continuous synthesis of the body of knowledge. To supplement existing information, knowledge of mycotoxins affecting animals, foods, humans, and plants, with more focus on types, toxicity, and prevention measures, including strategies employed in detoxification and rem...

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2015

There is an exigent necessity for development of environmental friendly bio-control agent(s) for ... more There is an exigent necessity for development of environmental friendly bio-control agent(s) for elimination of mosquito due to increased resistance resurgence against synthetic control agents. Mosquito control strategy will lay a strong foundation to malaria exclusion or it can be curbed to certain level especially in the developing nations. In this study, silver nanoparticles were synthesized by green chemistry approach using Tridax procumbens leaf extract as a reducing agent. The reaction medium involved in the synthesis process was optimized by statistical experimental design using response surface methodology to obtain better yield, uniform size, shape and stability. Further, these synthesized nanoparticles were confirmed through UV-Visible, FT-IR spectroscopy, PSA and SEM Subsequently, the bioefficacy of these particles were investigated on Anopheles stephensi for larvicidal and pupicidal activity. Interestingly, time period of 90 min, temperature of 76±2 °C, pH 7.2±2, 2 mM silver nitrate (AgNO3), 3mM PEG and 2mM PVP showed excellent parameters for bioprocess design for large scale production of stabilized nanoparticles. A concentration of 5 ppm of PVP stabilized nanoparticles exhibited 100% mortality. Thus, the obtained results clearly suggest that silver nanoparticles stabilized by PEG and PVP may have important function as stabilizers, dispersants as well as larvicides for mosquito control.

ABSTRACT Non-coding functional elements recently have proved to play vital functions in eukaryote... more ABSTRACT Non-coding functional elements recently have proved to play vital functions in eukaryotes worthy ignoring in the prokaryotic counter parts. We argue that elucidating these non-coding elements will lead to a better understanding of the differences coexisting between the Streptococci species, an important human pathogen responsible for vast diseases devastating the economy. The study analyzed 56 strains from NCBI, where 44,523 sequences were extracted by PERL script. Similarity search by Blast, Genemark and CPC revealed a total of 1443 potential sequences preceding functional studies by deploying Pfam, InterproScan and COG depicting 144 proteins allowing them to be designated as novel ones. The results potentially could be used as new vaccine targets, better understanding of the different biological niches; re-annotation also can be looked unto for potential genomic island identification and further wet-lab extensions research work for better understanding of the Streptococci family for further directions and incorporation of the identified proteins into database.

Malaria is a complex disease afflicting human race globally encompassing 1.2-2.7 million people a... more Malaria is a complex disease afflicting human race globally encompassing 1.2-2.7 million people annually. Thus, vector control is essential as sole malaria prevention strategy. It is worrying that though efforts are made to control mosquito vector borne organisms, the burden is still advancing rapidly due to resistance emergency, differential distribution of vectors and high genetic diversity. Therefore, the current research hypothesized to synthesis silver nanoparticles adopting green chemistry and further, the synthesized nanoparticles were investigated against the IV instar and pupal stage Anopheles stephensi. Results revealed that both SDS-AgNPs and Tween 20-AgNPs were more lethal on IV instar and pupa with 100% mortality at 5 ppm. Tridax procumbens extract (TPE) alone did not show significant mortality. LC 50 of SDS-AgNPs exhibited highest efficacy (1.900 & 1.719), closely followed by Tween 20-AgNPs (1.933 & 2.274) and TPE (1.235 & 1.321) for IV instar and pupa respectively. The findings strongly suggest that SDS-AgNPs and Tween 20-AgNPs could be potential for controlling Anopheles stephensi following thorough formulation studies. Further study for large scale production of biologically susceptible nanoparticles is the scope of the current findings.

There is an exigent necessity for development of environmental friendly bio-control agent(s) for ... more There is an exigent necessity for development of environmental friendly bio-control agent(s) for elimination
of mosquito due to increased resistance resurgence against synthetic control agents. Mosquito control
strategy will lay a strong foundation to malaria exclusion or it can be curbed to certain level
especially in the developing nations. In this study, silver nanoparticles were synthesized by green chemistry
approach using Tridax procumbens leaf extract as a reducing agent. The reaction medium involved in
the synthesis process was optimized by statistical experimental design using response surface methodology
to obtain better yield, uniform size, shape and stability. Further, these synthesized nanoparticles
were conﬁrmed through UV–Visible, FT-IR spectroscopy, PSA and SEM Subsequently, the bioefﬁcacy of
these particles were investigated on Anopheles stephensi for larvicidal and pupicidal activity.
Interestingly, time period of 90 min, temperature of 76 ± 2 C, pH 7.2 ± 2, 2 mM silver nitrate (AgNO
),
3 mM PEG and 2 mM PVP showed excellent parameters for bioprocess design for large scale production
of stabilized nanoparticles. A concentration of 5 ppm of PVP stabilized nanoparticles exhibited 100% mortality.
Thus, the obtained results clearly suggest that silver nanoparticles stabilized by PEG and PVP may
have important function as stabilizers, dispersants as well as larvicides for mosquito control.

Malaria is a complex disease afflicting human race globally encompassing 1.2-2.7 million people a... more Malaria is a complex disease afflicting human race globally encompassing 1.2-2.7 million people annually. Thus, vector control is essential as sole malaria prevention strategy. It is worrying that though efforts are made to control mosquito vector borne organisms, the burden is still advancing rapidly due to resistance emergency, differential distribution of vectors and high genetic diversity. Therefore, the current research hypothesized to synthesis silver nanoparticles adopting green chemistry and further, the synthesized nanoparticles were investigated against the IV instar and pupal stage Anopheles stephensi. Results revealed that both SDS-AgNPs and Tween 20-AgNPs were more lethal on IV instar and pupa with 100% mortality at 5 ppm. Tridax procumbens extract (TPE) alone did not show significant mortality. LC50 of SDS-AgNPs exhibited highest efficacy (1.900 & 1.719), closely followed by Tween 20-AgNPs (1.933 & 2.274) and TPE (1.235 & 1.321) for IV instar and pupa respectively. The findings strongly suggest that SDS-AgNPs and Tween 20-AgNPs could be potential for controlling Anopheles stephensi following thorough formulation studies. Further study for large scale production of biologically susceptible nanoparticles is the scope of the current findings.

Resistance emergency has necessitated continuous search for drugs with least toxicity, effective,... more Resistance emergency has necessitated continuous search for drugs with least toxicity, effective, affordable and eco-friendly which possess new mode of action to cater the rising emergency. In this study, T. procumbens was used for biogenic synthesis of silver nanoparticles and investigated for antibacterial and antifungal activity. Characterization was done by UV-Vis spectrum, SEM, XRD, EDAX and FTIR. The UV-vis spectrum λmax was observed at 452 nm. EDAX AgNPs revealed total yield of 96.7% with 100 % purity, whilst SEM and XRD revealed spherical and elongated shape with an average grain size of 3.973 nm. FTIR examination provided evidence for presence of primary amides, aromatic ketones and aliphatic amines groups that could be responsible for synthesis and stability of the synthesized silver nanoparticles. Bio potential analysis of the synthesized biogenic silver nanoparticles showed antimicrobial activity against the twelve human and fish pathogens tested with ≥ 10 mm zone of inhibition and among the eight fungal strains involved in this study, Penicillium restrictum MTCC 3391 and Trichoderma virens MTCC 794 recorded inhibition. The findings recommend the use of T. procumbens, a weed plant for biogenic nanoparticle production and can be applied as antimicrobial agent. Isolation and identification of the molecules acting as stabilizers and reducing agents is the scope of further research.

Non-coding functional elements recently have proved to play vital functions in eukaryotes worthy... more Non-coding functional elements recently have proved to play vital functions in
eukaryotes worthy ignoring in the prokaryotic counter parts. We argue that elucidating
these non-coding elements will lead to a better understanding of the differences coexisting
between the Streptococci species, an important human pathogen responsible
for vast diseases devastating the economy. The study analyzed 56 strains from NCBI,
where 44,523 sequences were extracted by PERL script. Similarity search by Blast,
Genemark and CPC revealed a total of 1443 potential sequences preceding functional
studies by deploying Pfam, InterproScan and COG depicting 144 proteins allowing
them to be designated as novel ones. The results potentially could be used as new
vaccine targets, better understanding of the different biological niches; re-annotation
also can be looked unto for potential genomic island identification and further wet-lab
extensions research work for better understanding of the Streptococci family for further
directions and incorporation of the identified proteins into database.

The research illuminates DHFR from Pneumocystis jiroveci as a newly potential drug target against... more The research illuminates DHFR from Pneumocystis jiroveci as a newly potential drug target against pneumonia. P. jiroveci DHFR sequence Q9UUP5 was obtained from Swiss-Prot database and deployed for 3-dimensional structure prediction. Sequence similarity templates searching found between P.j DHFR against 1CD2, 1VJ3 and 1DR1 paved the modeling with high confidence. The superimposition of the predicted template structures revealed the sequence identity of more than 30% and RMSD values of 4vs.1, 4vs.2, 4vs.3 and 4vs.5 and RMSD values 0.094, 0.093, 0.094 and 0.108 respectively; it comes under the expected range of <2Ȧ. The structure showed overall conservation domains involved in binding affinity, energy minimization value, as well as inter-subunit interactions. Our results provided a basis of structural modeling (threading), energy minimization, RMSD value, structural validation and evaluation, to compare the overall structure and functional amino acids dependent on P.j DHFR in Pneumocystis. Further analysis to show the differences found between the inter and intra species of P.j DHFR is a leeway to design inhibitors targeted specifically against Pneumocystis jiroveci pneumonia (PJP).

Asian Journal of Chemistry, 2021

Foods

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2015

There is an exigent necessity for development of environmental friendly bio-control agent(s) for ... more There is an exigent necessity for development of environmental friendly bio-control agent(s) for elimination
of mosquito due to increased resistance resurgence against synthetic control agents. Mosquito control
strategy will lay a strong foundation to malaria exclusion or it can be curbed to certain level
especially in the developing nations. In this study, silver nanoparticles were synthesized by green chemistry
approach using Tridax procumbens leaf extract as a reducing agent. The reaction medium involved in
the synthesis process was optimized by statistical experimental design using response surface methodology
to obtain better yield, uniform size, shape and stability. Further, these synthesized nanoparticles
were conﬁrmed through UV–Visible, FT-IR spectroscopy, PSA and SEM Subsequently, the bioefﬁcacy of
these particles were investigated on Anopheles stephensi for larvicidal and pupicidal activity.
Interestingly, time period of 90 min, temperature of 76 ± 2 C, pH 7.2 ± 2, 2 mM silver nitrate (AgNO
),
3 mM PEG and 2 mM PVP showed excellent parameters for bioprocess design for large scale production
of stabilized nanoparticles. A concentration of 5 ppm of PVP stabilized nanoparticles exhibited 100% mortality.
Thus, the obtained results clearly suggest that silver nanoparticles stabilized by PEG and PVP may
have important function as stabilizers, dispersants as well as larvicides for mosquito control.

Malaria is a complex disease afflicting human race globally encompassing 1.2-2.7 million people a... more Malaria is a complex disease afflicting human race globally encompassing 1.2-2.7 million people annually. Thus, vector control is essential as sole malaria prevention strategy. It is worrying that though efforts are made to control mosquito vector borne organisms, the burden is still advancing rapidly due to resistance emergency, differential distribution of vectors and high genetic diversity. Therefore, the current research hypothesized to synthesis silver nanoparticles adopting green chemistry and further, the synthesized nanoparticles were investigated against the IV instar and pupal stage Anopheles stephensi. Results revealed that both SDS-AgNPs and Tween 20-AgNPs were more lethal on IV instar and pupa with 100% mortality at 5 ppm. Tridax procumbens extract (TPE) alone did not show significant mortality. LC50 of SDS-AgNPs exhibited highest efficacy (1.900 & 1.719), closely followed by Tween 20-AgNPs (1.933 & 2.274) and TPE (1.235 & 1.321) for IV instar and pupa respectively. The findings strongly suggest that SDS-AgNPs and Tween 20-AgNPs could be potential for controlling Anopheles stephensi following thorough formulation studies. Further study for large scale production of biologically susceptible nanoparticles is the scope of the current findings.

Resistance emergency has necessitated continuous search for drugs with least toxicity, effective,... more Resistance emergency has necessitated continuous search for drugs with least toxicity, effective, affordable and eco-friendly which possess new mode of action to cater the rising emergency. In this study, T. procumbens was used for biogenic synthesis of silver nanoparticles and investigated for antibacterial and antifungal activity. Characterization was done by UV-Vis spectrum, SEM, XRD, EDAX and FTIR. The UV-vis spectrum λmax was observed at 452 nm. EDAX AgNPs revealed total yield of 96.7% with 100 % purity, whilst SEM and XRD revealed spherical and elongated shape with an average grain size of 3.973 nm. FTIR examination provided evidence for presence of primary amides, aromatic ketones and aliphatic amines groups that could be responsible for synthesis and stability of the synthesized silver nanoparticles. Bio potential analysis of the synthesized biogenic silver nanoparticles showed antimicrobial activity against the twelve human and fish pathogens tested with ≥ 10 mm zone of inhibition and among the eight fungal strains involved in this study, Penicillium restrictum MTCC 3391 and Trichoderma virens MTCC 794 recorded inhibition. The findings recommend the use of T. procumbens, a weed plant for biogenic nanoparticle production and can be applied as antimicrobial agent. Isolation and identification of the molecules acting as stabilizers and reducing agents is the scope of further research.

Non-coding functional elements recently have proved to play vital functions in eukaryotes worthy... more Non-coding functional elements recently have proved to play vital functions in
eukaryotes worthy ignoring in the prokaryotic counter parts. We argue that elucidating
these non-coding elements will lead to a better understanding of the differences coexisting
between the Streptococci species, an important human pathogen responsible
for vast diseases devastating the economy. The study analyzed 56 strains from NCBI,
where 44,523 sequences were extracted by PERL script. Similarity search by Blast,
Genemark and CPC revealed a total of 1443 potential sequences preceding functional
studies by deploying Pfam, InterproScan and COG depicting 144 proteins allowing
them to be designated as novel ones. The results potentially could be used as new
vaccine targets, better understanding of the different biological niches; re-annotation
also can be looked unto for potential genomic island identification and further wet-lab
extensions research work for better understanding of the Streptococci family for further
directions and incorporation of the identified proteins into database.