Hazim Khalifa

Dr. Hazim Khalifa

Devision of Clinical Research, Medical Mycology Research Center, Chiba University
orcid

Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

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

Representative Publications

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14 August 2025 in Frontiers in Cellular and Infection Microbiology
Verified
Journal Article
Open access
PDF file
Hazim KhalifaHazim Khalifa
Hazim Khalifa
AOAtef Oreiby
Atef Oreiby
TMTemesgen Mohammed
Temesgen Mohammed
MAMohamed A. A. Abdelhamid
Mohamed A. A. Abdelhamid
ESEssam Nageh Sholkamy
Essam Nageh Sholkamy
RFRagab M. Fereig
Ragab M. Fereig
The escalating prevalence of multidrug-resistant (MDR) bacteria presents a critical global health challenge, necessitating the urgent development of alternative antimicrobial strategies. Silver nanoparticles (AgNPs) have emerged as promising antimicrobial agents due to their broad-spectrum activity, unique physicochemical properties, and multiple mechanisms of bacterial inhibition. Their nanoscale size, high surface area-to-volume ratio, and ability to generate reactive oxygen species (ROS) make them highly effective against both Gram-positive and Gram-negative bacteria. AgNPs exert their antimicrobial effects through diverse mechanisms, including membrane disruption, protein and DNA interactions, enzymatic inhibition, and interference with bacterial metabolic pathways. Despite their potent antibacterial activity, concerns regarding bacterial adaptation, cytotoxicity, and non-specific interactions have prompted extensive research into innovative delivery systems to enhance AgNP efficacy while minimizing adverse effects. This review comprehensively explores the synthesis methods and physical properties of AgNPs, emphasizing their antimicrobial mechanisms and emerging resistance patterns. Additionally, we discuss advanced targeted delivery approaches, including surface functionalization, biopolymer encapsulation, liposomal carriers, and stimuli-responsive nanoplatforms, which enhance the stability, selectivity, and controlled release of AgNPs. These strategies not only improve AgNP bioavailability but also reduce host toxicity and prevent bacterial resistance development. Furthermore, we highlight future directions in AgNP-based antimicrobial therapy, such as combinatorial treatments with antibiotics, advanced nanostructure modifications, and the integration of AgNPs into wound dressings, coatings, and biomedical devices. By synthesizing recent advancements, this review underscores the transformative potential of AgNPs as next-generation antimicrobial agents to combat MDR bacterial infections. Addressing the current limitations and optimizing AgNP formulations will be crucial for their successful clinical translation and for mitigating the global antibiotic resistance crisis.

23 May 2024 in Foods
Verified
Journal Article
Open access
PDF file
Hazim KhalifaHazim Khalifa
Hazim Khalifa
LSLamek Shikoray
Lamek Shikoray
Mohamed Yousif Ibrahim MohamedMohamed Yousif Ibrahim Mohamed
Mohamed Yousif Ibrahim Mohamed
Ihab HabibIhab Habib
Ihab Habib
TMTetsuya Matsumoto
Tetsuya Matsumoto
Veterinary medications are necessary for both contemporary animal husbandry and food production, but their residues can linger in foods obtained from animals and pose a dangerous human risk. In this review, we aim to highlight the sources, occurrence, human exposure pathways, and human health effects of drug residues in food-animal products. Following the usage of veterinary medications, pharmacologically active compounds known as drug residues can be found in food, the environment, or animals. They can cause major health concerns to people, including antibiotic resistance development, the development of cancer, teratogenic effects, hypersensitivity, and disruption of normal intestinal flora. Drug residues in animal products can originate from variety of sources, including water or food contamination, extra-label drug use, and ignoring drug withdrawal periods. This review also examines how humans can be exposed to drug residues through drinking water, food, air, and dust, and discusses various analytical techniques for identifying these residues in food. Furthermore, we suggest some potential solutions to prevent or reduce drug residues in animal products and human exposure pathways, such as implementing withdrawal periods, monitoring programs, education campaigns, and new technologies that are crucial for safeguarding public health. This review underscores the urgency of addressing veterinary drug residues as a significant and emerging public health threat, calling for collaborative efforts from researchers, policymakers, and industry stakeholders to develop sustainable solutions that ensure the safety of the global food supply chain.

21 June 2022 in Pathogens
Verified
Journal Article
Open access
PDF file
MBMohamed Ahmed Borham
Mohamed Ahmed Borham
AOAtef Orieby
Atef Orieby
AEAttia El-Gedawy
Attia El-Gedawy
YHYamen Hegazy
Yamen Hegazy
Hazim KhalifaHazim Khalifa
Hazim Khalifa
TMTetsuya Matsumoto
Tetsuya Matsumoto
Bovine tuberculosis is a serious infectious disease affecting a wide range of domesticated and wild animals, representing a worldwide economic and public health burden. The disease is caused by Mycobacteriumbovis and infrequently by other pathogenic mycobacteria. The problem of bovine tuberculosis is complicated when the infection is associated with multidrug and extensively drug resistant M. bovis. Many techniques are used for early diagnosis of bovine tuberculosis, either being antemortem or postmortem, each with its diagnostic merits as well as limitations. Antemortem techniques depend either on cellular or on humoral immune responses, while postmortem diagnosis depends on adequate visual inspection, palpation, and subsequent diagnostic procedures such as bacterial isolation, characteristic histopathology, and PCR to reach the final diagnosis. Recently, sequencing and bioinformatics tools have gained increasing importance for the diagnosis of bovine tuberculosis, including, but not limited to typing, detection of mutations, phylogenetic analysis, molecular epidemiology, and interactions occurring within the causative mycobacteria. Consequently, the current review includes consideration of bovine tuberculosis as a disease, conventional and recent diagnostic methods, and the emergence of MDR-Mycobacterium species.

1 May 2016 in Antimicrobial Agents and Chemotherapy
Verified
Journal Article
Closed access
PDF file
SEShimaa S. Elnahriry
Shimaa S. Elnahriry
Hazim KhalifaHazim Khalifa
Hazim Khalifa
ASAhmed M. Soliman
Ahmed M. Soliman
AAAshraf M. Ahmed
Ashraf M. Ahmed
AHAlaaddin M. Hussein
Alaaddin M. Hussein
TSTadashi Shimamoto
Tadashi Shimamoto

1 May 2016 in International Journal of Antimicrobial Agents
Verified
Journal Article
Closed access
Hazim KhalifaHazim Khalifa
Hazim Khalifa
AAAshraf M. Ahmed
Ashraf M. Ahmed
AOAtef F. Oreiby
Atef F. Oreiby
AEAmal M. Eid
Amal M. Eid
TSToshi Shimamoto
Toshi Shimamoto
TSTadashi Shimamoto
Tadashi Shimamoto

13 February 2017 in Microbial Drug Resistance
Verified
Journal Article
Closed access
Hazim KhalifaHazim Khalifa
Hazim Khalifa
ASAhmed M. Soliman
Ahmed M. Soliman
AAAshraf M. Ahmed
Ashraf M. Ahmed
TSToshi Shimamoto
Toshi Shimamoto
THToshinori Hara
Toshinori Hara
TSTadashi Shimamoto
Tadashi Shimamoto
The emergence and spread of carbapenem-resistant gram-negative bacteria poses a serious threat to human health worldwide. Currently, little is known about the molecular mechanisms underlying carbapenem resistance and their prevalence among gram-negative bacteria in Egypt. In this study, we analyzed carbapenemase production in gram-negative bacteria isolated from hospitalized patients in Egypt in 2014. All isolates were subjected to phenotypic and genotypic susceptibility testing for carbapenem resistance. Our results indicated a high level of carbapenem-resistant gram-negative bacteria in Egypt, with 50.8% of the isolates harboring at least one carbapenem resistance gene. OXA-48-like and NDM-1 were the most prevalent carbapenemases, being detected in 49.2%, and 47.7% of carbapenemase-positive isolates, respectively, whereas Verona integron-encoded metallo-β-lactamase (VIM) was detected in only 26.2% of carbapenemase-positive isolates. This study reports for the first time carbapenemase-producing Serratia marcescens , Morganella morganii , and bla VIM-1-like -producing Pseudomonas aeruginosa in Egypt. It is also the first demonstration of the coexistence of different carbapenemases, being detected in 21.5% of carbapenemase-positive isolates. Effective antibiotic supervision, regional surveillance, and early detection of carbapenemase producers are imperative to prevent their future spread to epidemic levels.
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