Akamu Ewunkem

Dr. Akamu Ewunkem

orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
25 May 2022 in Antibiotics
Verified
Journal Article
Open access
PDF file
SBSada Boyd
Sada Boyd
KRKristen Rhinehardt
Kristen Rhinehardt
AEAkamu Ewunkem
Akamu Ewunkem
SHScott H. Harrison
Scott H. Harrison
Misty ThomasMisty Thomas
Misty Thomas
JJJoseph Graves jr
Joseph Graves jr
The rise in antimicrobial resistant bacteria have prompted the need for antibiotic alternatives. To address this problem, significant attention has been given to the antimicrobial use and novel applications of copper. As novel applications of antimicrobial copper increase, it is important to investigate how bacteria may adapt to copper over time. Here, we used experimental evolution with re-sequencing (EER-seq) and RNA-sequencing to study the evolution of copper resistance in Escherichia coli. Subsequently, we tested whether copper resistance led to rifampicin, chloramphenicol, bacitracin, and/or sulfonamide resistance. Our results demonstrate that E. coli is capable of rapidly evolving resistance to CuSO4 after 37 days of selection. We also identified multiple de novo mutations and differential gene expression patterns associated with copper, most notably those mutations identified in the cpx gene. Furthermore, we found that the copper resistant bacteria had decreased sensitivity when compared to the ancestors in the presence of chloramphenicol, bacitracin, and sulfonamide. Our data suggest that the selection of copper resistance may inhibit growth in the antimicrobials tested, resulting in evolutionary trade-offs. The results of our study may have important implications as we consider the antimicrobial use of copper and how bacteria may respond to increased use over time.

29 December 2023 in Gene & Protein in Disease
Verified
Journal Article
Open access
PDF file
AEAkamu Ewunkem
Akamu Ewunkem
ZWZahirah J. Williams
Zahirah J. Williams
NJNiore S. Johnson
Niore S. Johnson
JBJustice L. Brittany
Justice L. Brittany
AMAdesewa Maselugbo
Adesewa Maselugbo
KNKyle Stephen Nowlin
Kyle Stephen Nowlin
The frequent use of antibiotics has created favorable conditions for bacteria to develop resistance. Bacterial resistance is an issue for global health killing at least 1 million people worldwide annually. The quest for new and effective antimicrobials with activities against resistance bacteria demands immediate attention. The use of nanoparticles as antimicrobials alternatives to conventional antibiotics may have the potential to combat bacterial resistance. Silver nanoparticles, silver nanoparticles have captivated the interest of most researchers by virtue of their broad-range antimicrobial activity against bacteria due to their strong biocidal effect against microorganisms. Silver nanoparticles have been traditionally synthesized by physical chemical and biological process. However, biosynthesis of silver nanoparticles from wings of carpenter bees Xylocopa virginica, which is abundantly available in summer in the United States of America, is yet to be explored. Herein, we report the synthesis of silver nanoparticles using wing extract of carpenter bees X. virginica. Subsequently the biosynthesized nanoparticles were characterized by UV–Visible absorption spectroscopy and scanning electron microscopy (SEM). Furthermore, the antimicrobial activity of the biosynthesized nanoparticles was investigated against two common Gram-negative and Gram-positive pathogenic bacteria viz Klebsiella pneumonia, Escherichia coli, Micrococcus luteus and Staphylococcus aureus using microdilution method. The results of this study indicate that biosynthesized silver nanoparticles from X. virginica wing extract showed an absorption band at 440 nm and SEM revealed spherical nanoparticles 20- 60 nm in size. Additionally, biosynthesizes silver nanoparticles from the wings of X. virginica exhibited antimicrobial activity against all the tested bacteria signifying their biomedical, pharmaceutical, and agricultural potential.

17 March 2023 in Antibiotics
Verified
Journal Article
Open access
PDF file
OJOlusola Jeje
Olusola Jeje
AEAkamu Ewunkem
Akamu Ewunkem
LJLiesl K Jeffers-Francis
Liesl K Jeffers-Francis
JJJoseph Graves jr
Joseph Graves jr
The prevalence of multidrug-resistant bacteria and their increased pathogenicity has led to a growing interest in metallic antimicrobial materials and bacteriophages as potential alternatives to conventional antibiotics. This study examines how resistance to excess iron (III) influences the evolution of bacteriophage resistance in the bacterium Escherichia coli. We utilized experimental evolution in E. coli to test the effect of the evolution of phage T7 resistance on populations resistant to excess iron (III) and populations without excess iron resistance. Phage resistance evolved rapidly in both groups. Dual-resistant (iron (III)/phage) populations were compared to their controls (excess iron (III)-resistant, phage-resistant, no resistance to either) for their performance against each stressor, excess iron (III) and phage; and correlated resistances to excess iron (II), gallium (III), silver (I) and conventional antibiotics. Excess iron (III)/phage-resistant populations demonstrated superior 24 h growth compared to all other populations when exposed to increasing concentrations of iron (II, III), gallium (III), ampicillin, and tetracycline. No differences in 24 h growth were shown between excess iron (III)/phage-resistant and excess iron (III)-resistant populations in chloramphenicol, sulfonamide, and silver (I). The genomic analysis identified selective sweeps in the iron (III) resistant (rpoB, rpoC, yegB, yeaG), phage-resistant (clpX →/→ lon, uvaB, yeaG, fliR, gatT, ypjF, waaC, rpoC, pgi, and yjbH) and iron (III)/phage resistant populations (rcsA, hldE, rpoB, and waaC). E. coli selected for resistance to both excess iron (III) and T7 phage showed some evidence of a synergistic effect on various components of fitness. Dual selection resulted in correlated resistances to ionic metals {iron (II), gallium (III), and silver (I)} and several conventional antibiotics. There is a likelihood that this sort of combination antimicrobial treatment may result in bacterial variants with multiple resistances.

29 September 2022 in International Journal of Zoology
Verified
Journal Article
Open access
PDF file
AEAkamu Ewunkem
Akamu Ewunkem
KAKyle Agee
Kyle Agee
Spiders (Arachnida, Araneae) represent one of the largest groups of organisms on Earth with more than 45,000 recorded species found in nearly all terrestrial communities. In these communities, spiders are obligate predators and generalist consumers regulating the density of pests. Spiders have a stupefying array of prey hunting strategies ranging from ambushing to the use of complex silk nares. Spider silk is incredibly tough and can be used for many applications such as wrapping and immobilization, catching prey, as dragline to connect spiders to the web, as ballooning to aid dispersal of juveniles, as shelters in burrows, for mating, and as egg sacs (or cocoons). Typically, spider egg sacs are multilayered, complex structures that physically protect the eggs and hatchlings against parasitoids, predators as well as changing temperatures. Much research has been undertaken to elucidate the ecological role of spiders and the mechanical characteristics of silks. However, few studies have examined the parental care of spiders and the role of egg sacs. This review goes into great detail about spider parental care and the functions of egg sacs.

21 November 2024 in Antibiotics
Verified
Journal Article
Open access
PDF file
AEAkamu Ewunkem
Akamu Ewunkem
LMLydia Camden Merrills
Lydia Camden Merrills
ZWZahirah Williams
Zahirah Williams
BJBrittany Justice
Brittany Justice
UIUchenna Iloghalu
Uchenna Iloghalu
DSDinesh Singh
Dinesh Singh
Background: Infectious diseases caused by bacteria are life-threating and are among the major causes of death in the world. Antibiotics have offered humans a new approach to infection control. Antibiotics are reckoned as the “magic bullets” for the fight against bacterial infections, therefore increasing life expectancy and decreasing mortality and morbidity. However, the overuse of antibiotics has resulted in the persistent growth of resistant bacterial pathogens. New antimicrobial approaches against resistant pathogens are being examined. Mushrooms seem to be a promising, and possibly more efficient, alternative method to that of conventional antimicrobials. This work aimed to investigate the phytochemical constituents and antimicrobial potential of ethanolic, aqueous, and dual solvent extracts of mushroom Ganoderma lucidum. Methods: The antimicrobial studies were carried out by broth dilution against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. The present research work was also carried out to examine genomic changes associated with ethanolic, aqueous, and dual solvent extracts of G. lucidum in S. aureus and E. coli. Results: Our data quantitatively showed that all the extracts of G. lucidum were found to exhibit various degrees of antimicrobial effects against S. aureus and E. coli where the ethanolic extract exhibited the most potent antimicrobial activity. SEM images showed untreated cells with normal cell characteristics while, after treatment with extracts of G. lucidum, cells appeared damaged with irregular cell surfaces and cell wall defacement. The results of HPLC analysis showed that ethanolic and aqueous extract of G. lucidum consisted of beta[1-3] glucans, ganoderic acid, and triterpenoids. Genomic analysis identified selective sweeps in several genes associated with growth, biosynthesis transport, and stress. Conclusions: This study concludes that the extracts of three solvents of G. lucidum have antimicrobial activity against infectious bacteria causing morphological changes and the acquisition of mutations in genes. Therefore, the extracts of G. lucidum may be candidates for preventing infectious diseases in the future. Ganoderma lucidum mushroom is therefore a reliable source of antimicrobial agent that can be used against infectious diseases.

1 January 2023 in AIMS Microbiology
Verified
Journal Article
Open access
PDF file
AEAkamu Ewunkem
Akamu Ewunkem
ABA'LYiha F. Beard
A'LYiha F. Beard
BJBrittany L. Justice
Brittany L. Justice
SPSabrina L. Peoples
Sabrina L. Peoples
JMJeffery A. Meixner
Jeffery A. Meixner
UIUchenna B. Iloghalu
Uchenna B. Iloghalu
Natural surfaces with remarkable properties and functionality have become the focus of intense research. Heretofore, the natural antimicrobial properties of insect wings have inspired research into their applications. The wings of cicadas, butterflies, dragonflies, and damselflies have evolved phenomenal anti-biofouling and antimicrobial properties. These wings are covered by periodic topography ranging from highly ordered hexagonal arrays of nanopillars to intricate “Christmas-tree” like structures with the ability to kill microbes by physically rupturing the cell membrane. In contrast, the topography of honeybee wings has received less attention. The role topography plays in antibiofouling, and antimicrobial activity of honeybee wings has never been investigated. Here, through antimicrobial and electron microscopy studies, we showed that pristine honeybee wings displayed no microbes on the wing surface. Also, the wings displayed antimicrobial properties that disrupt microbial cells and inhibit their growth. The antimicrobial activities of the wings were extremely effective at inhibiting the growth of Gram-negative bacterial cells when compared to Gram-positive bacterial cells. The fore wing was effective at inhibiting the growth of Gram-negative bacteria compared to Gram-positive samples. Electron microscopy revealed that the wings were studded with an array of rough, sharp, and pointed pillars that were distributed on both the dorsal and ventral sides, which enhanced anti-biofouling and antimicrobial effects. Our findings demonstrate the potential benefits of incorporating honeybee wings nanopatterns into the design of antibacterial nanomaterials which can be translated into countless applications in healthcare and industry.