C.O. Esimone

Nnamdi Azikiwe University | Unizik · Department of Pharmaceutical Microbiology and Biotechnology

We previously demonstrated that the overall number of regulatory T (Treg) cells decrease proportionately with helper CD4⁺ T cells and their frequencies increase in antiretroviral therapy (ART)-naive human immunodeficiency virus type-1 (HIV-1) infected individuals. The question now is whether the discrepancies in Treg cell numbers and frequencies ar...

The study investigated the correlates of depression, anxiety and stress among pharmacy and nursing students in a university in south-south Nigeria, and explored the relationship between academic demands and mental health.

The study assessed the practice, and risk perception, of self-medication among pregnant women residing in Awka Nigeria.

The prevalence, molecular characterization, pathogenicity and antibioticsensitivity pattern of Clostridioides difficile from clinical samples in South-Eastern Nigeria wereevaluated in this study. Stool samples (450) were collected from patientsinsome selected public and private-owned clinics in the five South-Eastern states. Standard bacteriologica...

This study presents LHRH conjugated drug delivery via a magnetite nanoparticle-modified microporous Poly-Di-Methyl-Siloxane (PDMS) system for the targeted suppression of triple-negative breast cancer cells. First, the MNP-modified PDMS devices are fabricated before loading with targeted and untargeted cancer drugs. The release kinetics from the dev...

Human Immunodeficiency Virus (HIV) is a global public health challenge that has resulted in millions of deaths worldwide. Despite the introduction of the Highly Active Antiretroviral Therapy (HAART) regimen, which has significantly improved the life expectancy of HIV-positive individuals, there is still no cure for this disease. Therefore, alternat...

Endophytes have proven to be the promising sources of biologically active products which are of interest for specific medicinal applications. In this study, secondary metabolites of an endophytic fungus isolated from fresh leaves of Ageratum conyzoides was investigated for antimicrobial and immunomodulatory properties. Isolation of the endophytic f...

Introduction in areas with intense perennial malaria transmission, limited data is available on the impact of environmental conditions especially rainfall on naturally acquired immunity against promising malaria vaccine candidates. For this reason, we have compared IgG antibody responses specific to Plasmodium spp. derived MSP3 and UB05 vaccine can...

Delays in malaria diagnosis increase treatment failures and deaths. In endemic regions, standard diagnostic methods are microscopy and malaria rapid diagnostic tests (mRDTs) detecting Plasmodium falciparum histidine-rich protein 2/3 (PFHRP2/PFHRP3), but gene deletions can allow certain parasites to remain undetected. We enlisted a cohort comprising...

FIP International Conference Brisbane, Australia, 24-28 September, 2023.

Paediatric immunisation had been relevant in reducing the widespread of Hepatitis B virus, as an outcome of the induction of hepatitis B surface antigen specific-IgG antibodies (anti-HBs). Studies revealed alteration effects of memory B cells during antiretroviral therapy (ART). We aimed at assessing anti-HBs response profile with respect to the mo...

Vertical HIV-1 infection impairs the development of DENV specific immunity in children and probably exacerbates plasma accumulation of DENV NS1 protein.

A new siderophore, serratiochelin D (1), was isolated from a soil-derived, non-pigmented strain of Serratia marcescens along with two previously reported siderophores, serratiochelins A and B. Siderophores were obtained after cultivating the bacterium in an iron-deficient medium, and the chemical structures were elucidated based on HPLC-UV, mass sp...

Background Diarrhoea is a major cause of childhood disease in the developing countries. This experimental study investigated the prevalence of ESBL and MBL genes in enteropathogenic strains of Escherichia coli and Salmonella spp. isolated from diarrheagenic children in Awka, Nigeria. Methods Two hundred stool samples were collected from diarrhea p...

Endophytic fungi can inherently establish mutual relationships with host plants while also synthesizing similar and enhanced bioactive compounds as the host. The investigation of exploitable antibacterial and antioxidant bioactive compounds produced by fungal endophytes from selected medicinal plants was the focus of this study. Following standard...

Antimicrobial resistance is a threat to public health. This study investigated the occurrence of ESBL and colistin resistance among Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa recovered from clinical samples (n=500) in a tertiary teaching hospital in Abakaliki, Nigeria. The samples were bacteriologically analyzed using select...

In the science of drug discovery, ultraviolet (UV) irradiation has been applied to induce mutagenesis in fungi to provide possibilities for the stimulation or enhancement of fungal biosynthetic capabilities. This study was carried out to evaluate the effect of UV radiation on the biosynthesis of antibacterial secondary metabolites in an endophytic...

In the science of drug discovery, ultraviolet (UV) irradiation has been applied to induce mutagenesis in fungi to provide possibilities for the stimulation or enhancement of fungal biosynthetic capabilities. This study was carried out to evaluate the effect of UV radiation on the biosynthesis of antibacterial secondary metabolites in an endophytic...

Recent upsurge in mortality rate and long hospital stays in hospitals as a result of antimicrobial resistance caused by multidrug resistant bacteria is a huge burden to public health sector. Intensive search for more effective and newer agents to deal with these problems. Endophytes are a novel source of potentially useful medicinal compounds. Aim:...

The antimicrobial properties of secondary metabolites produced by the endophytic Aspergillus brunneoviolaceus associated with the Nigerian plant Bryophyllum pinnatum were investigated in this study. Standard procedures were followed for fungal isolation and identification, as well as fermentation and extraction of fungal secondary metabolites. The...

Background and Objectives: This study investigated the incidence and antibiotic susceptibility profile of extended spectrum β-lactamase (ESBL) producing uropathogenic Escherichia coli recovered from HIV/AIDS patients in Awka metropolis, Nigeria. Materials and Methods: A total of 363 urine samples were bacteriologically analyzed for the isolation of...

Endophytic fungi remain an unexplored reservoir of chemical diversity, and have become the primary focus is several bio-prospecting programs. This study was carried out to detect the constituents and bioactivity of the secondary metabolites of an endophytic Lasiodiplodia theobromae associated with Musa paradisiaca. Following standard protocols, the...

Background: Recent reports suggest that pregnant women living in holoendemic regions of sub-Sahara Africa die in great numbers annually due to malaria disease resulting from their higher susceptibility, reduced immunity and demographic associated factors. This work investigated the prevalence of Plasmodium falciparum in pregnant women attending an...

Bioactive compounds of microbial origin remain the frontline for novel drug discovery and development in the pharmaceutical industry. Endophytic fungi are gaining much attention as reservoirs of bioactive compounds with beneficial therapeutic activities. The present study is focused on evaluating the chemical compositions and antimicrobial activit...

Introduction: The genetic diversity of Plasmodium falciparum poses a threat to the development and implementation of malaria control strategies. Thus, there is a need for continuous surveillance of its genetic diversity, especially amongst the parasite's reservoir's asymptomatic population. Methodology: Three cohorts comprising children under te...

This study reported the antiplasmodial and immunomodulatory activities of extracts of endophytic fungi isolated from Azadirachta indica. The extracts were evaluated for potential in-vivo and in-vitro antiplasmodial activity using murine malaria models and microtechnique methods respectively. Immunomodulatory potentials of the extracts were assessed...

Miconazole is a Biopharmaceutics Classification System (BCS) class II drug, thus limiting its oral bioavailability. Nanosponges can improve the oral bioavailability of poorly soluble drugs and sustain their release. The work was aimed at formulating miconazole nanosponges to enhance its solubility and consequently, oral bioavailability. Batches of...

Natural products from Nigerian plants are significant in the search for drug compounds, as they contribute new compounds with biological properties to the fight against resistant pathogens, hence the study. Fresh leaves of M. indica were prepared for fungal isolation, identification, fermentation, and secondary metabolites extraction. The extract,...

Objectives: Dengue virus (DENV) infection is a mosquito-borne disease that stands out as one of the major public health issues and has a wide-ranging geographical distribution throughout the tropics and subtropics. The general alarming increase in the number of cases over the last two decades can be attributed to an extent to the change in national...

Purpose: To evaluate the xenosiderophoric properties of siderophores produced by Serratia marcescens towards Acinetobacter baumannii, Staphylococcus aureus and Mycobacterium tuberculosis. Methods: A non-pigmented strain of S. marcescens was isolated from soil after cultivation in iron-limited LB medium. The isolate was identified using both bioche...

Background The occurrence of artemisinin resistance (ART)-associated polymorphism of Plasmodium falciparum K13-propeller ( pfk13 ) gene before and after the introduction of artemisinin-based combination therapy (ACT) in two regions of Nigeria was investigated in this study. Regular surveillance is necessary to make a definite conclusion on the emer...

Bacterial Vaginosis (BV) is a polymicrobial syndrome characterized by a shift in the vaginal flora from a predominant population of Lactobacilli to a replacement with anaerobes. Vaginal suppositories containing L. pentosus KCA1 were formulated using glycerol-gelatin base. A prospective and follow-up community-based study was done. Vaginal samples w...

Background: The presence of infectious microorganisms in orally-administered herbal medicines is of great clinical importance and may portend grave danger to unsuspecting users of the products. Objectives: This study, therefore, investigated the presence of multidrug-resistant (MDR) Gram-negative bacteria in orally-administered herbal preparation...

The importance of the availability of good antioxidants for human health and the associated health challenges as a result of its deficiency calls for a search for newer bioactive compounds with the potentials to scavenge free radicals thus preventing oxidative stress. In this study, the antioxidant activities of some endophytic fungal extracts C...

Background Gram-negative bacteria (GNB) including Escherichia coli , Pseudomonas aeruginosa , and Klebsiella pneumoniae represent the most relevant reservoir of resistance genes such as metallo-β-lactamase (MBL) and AmpC genes that give them the undue advantage to resist antimicrobial onslaught. This study aimed to investigate the occurrence of MBL...

Background Plant endophytic fungi have been recognized as an important and novel resource of natural bioactive products with potential application in different fields of life. Purpose The present work evaluated the antioxidant and immunosuppressive activities of the extracts of endophytic fungi isolated from Psidium guajava and Newbouldia laevis....

Little is known about the molecular basis of antibiotic resistance among uropathogens in Southeast Nigeria. The aim of the study was to characterize enterobacterial uropathogens with respect to drug resistance. One hundred (100) enterobacterial uropathogens were studied. Their antibiotic susceptibility patterns were evaluated using disk diffusion,...

Background: A reversal of chloroquine (CQ) resistance following a period of withdrawal has raised the possibility of its re-introduction. This study evaluated the current prevalence of Pfcrt and Pfmdr1 alleles in Plasmodium falciparum isolates, 11 years after CQ withdrawal in Southeast Nigeria. Methods: Filter-paper blood samples were collected...

The revised edition of this chapter has been carefully and entirely rewritten. As a general rule, all sections have been revised and updated with current knowledge, more recent references included, and some sections expanded. Of particular note is the incorporation of significant additional materials in both sections dealing with some biological ac...

The use of antiretroviral (ARV) has been one of the most effective means of preventing vertical transmission of the human immunodeficiency virus (HIV) to exposed children born of HIV infected mothers. Nevertheless, responses to childhood vaccination against Hepatitis B virus (HBV) infections remain suboptimal in HIV exposed uninfected children irre...

The use of antiretroviral (ARV) has been one of the most effective means of preventing vertical transmission of the human immunodeficiency virus (HIV) to exposed children born of HIV infected mothers. Nevertheless, responses to childhood vaccination against Hepatitis B virus (HBV) infections remain suboptimal in HIV exposed uninfected children irre...

There have been several modifications in the use of immune stimulating complexes as adjuvants, such as the replacement of phospholipids with saponin content. Not much research has been done on the use of local alternatives. This actually instigated the use of a local alternative saponin source from Carica papaya leaves to formulate Iscomatrix adjuv...

Fungi remain a promising source of novel biologically active compounds with potentials in drug discovery and development. This study was aimed at investigating the secondary metabolites from endophytic Fusarium equiseti and Epicoccum sorghinum associated with leaves of Carica papaya collected from Agulu, Anambra State, Nigeria. Isolation of the end...

Background Immunoglobulin G (IgG)-specific responses against Plasmodium falciparum merozoite antigens such as the merozoite surface protein 3 (MSP3) and UBO5 are known to play critical roles in parasitaemia control and protection from symptomatic illness. However, when there is intense perennial malaria transmission coupled with concurrent infectio...

CITATIONS 0 READS 81 12 authors, including: Some of the authors of this publication are also working on these related projects: Gout, hyperuricemia and associated diseases View project Development of Feed safety plan and feed factory inspection programme in Cameroon View project Abel Lissom

Endophytic fungi associated with Nigerian plants have recently generated significant interest in drug discovery programmes due to their immense potential to contribute to the discovery of new bioactive compounds. This study was carried out to investigate the secondary metabolites of endophytic fungi isolated from leaves of Newbouldia laevis, Ocimum...

Background To our knowledge, there is no prior randomized study on the utility of Syferol-IHP (blend of virgin coconut oil and Ocimum sanctum oil) when coadministered with a triple therapy schedule. Aim This study determined the efficacy and safety of Syferol-IHP as adjunct to conventional triple therapy for the treatment of peptic ulcer disease (...

Pediatric vaccination against Hepatitis B Virus (HBV) leads to the induction of immunoglobulin G (IgG) antibodies specific to hepatitis B surface antigen (anti-HBs) consisting of four IgG subclasses. In the context of potential immuno-suppression arising from neonatal infection with the Immunodeficiency virus type one (HIV) an analyses of the anti-...

This study was conducted to investigate the incidence of community acquired extended-spectrum β-lactamase (ESBL)-producing bacteria among asymptomatic students of Nnamdi Azikiwe University, Awka, Anambra State, South-East Nigeria. A total of 102 non-duplicate strains of Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa were isolate...

Due to ever-growing insecticide resistance in mosquito vectors and environmental contamination by synthetic insecticides, plants may be a source of alternative agents for mosquito control. Therefore, the aim of this study was to investigate the mosquito oviposition-deterrent and ovicidal activities of different solvent fractions and essential oils...

Objectives: Gram-negative bacteria represent the most relevant reservoir of resistance to antibiotics in the environment. The natural selection of resistant clones of bacteria in the environment by antimicrobial selective pressure is a relevant mechanism for spreading antibiotic resistance traits in both the community and hospital environment. This...

The overall aim of this study was to evaluate the HIV-1 RNA viral load, CD4 count, and some haematological parameters among HIV treatment naïve subjects in Enugu metropolis. Blood samples were collected from all the participants and their HIV-1 status confirmed with immunoblot confirmatory test. Haematological parameters and CD4 count were evaluate...

Abstract Background In West and Central Africa areas of endemic Loa loa infections overlap with regions of high prevalence of human immunodeficiency virus type 1 (HIV-1) infections. Because individuals in this region are exposed to filarial parasites from birth, most HIV-1 infected individuals invariably also have a history of filarial parasite inf...

Some few studies on the endophytic fungal populations of Nigerian medicinal plants have confirmed the enormous potentials which abound in these organisms as sources of novel bioactive molecules. These studies highlight the need to further explore Nigeria’s plant biodiversity for endophytes producing biologically important molecules. In our study, a...

The endophytic fungus Aspergillus aculeatus isolated from leaves of the papaya plant Carica papaya was fermented on solid rice medium, yielding a new L-tryptophan-L-phenyllactic acid conjugate (1) and thirteen known compounds (11, 14–25). In addition, an OSMAC approach was employed by adding eight different sodium or ammonium salts to the rice medi...

Background: The high level of maternal mortality and morbidity as a result of complications due to childbirth is unacceptable. The impact of quality medicines in the management of these complications cannot be overemphasized. Most of those medicines are sensitive to environmental conditions and must be handled properly. In this study, the quality...

This study was carried out to determine the compliance of different brands of Hepatitis B vaccines marketed in open markets across South-Eastern Nigeria with Pharmacopoeial standards for safety and immunogenicity. Four different commercial brands of hepatitis B vaccines (Hepavax, Euvax, Sii and Engerix brands) were purchased from open markets acros...

Introduction: The membrane proximal external region (MPER) of HIV-1 envelope glycoprotein-41 (gp41) is targeted by several broadly neutralizing antibodies whose conserved linear epitopes are promising targets for vaccine design. However, a formidable challenge has remained the difficulty to design and deliver MPER based immunogens for the efficient...