Polymeric Nanomaterials for Efficient Delivery of Antimicrobial Agents

Bacterial infections have threatened the lives of human beings for thousands of years either as major diseases or complications. The elimination of bacterial infections has always occupied a pivotal position in our history. For a long period of time, people were devoted to finding natural antimicrobial agents such as antimicrobial peptides (AMPs), antibiotics and silver ions or synthetic active antimicrobial substances including antimicrobial peptoids, metal oxides and polymers to combat bacterial infections. However, with the emergence of multidrug resistance (MDR), bacterial infection has become one of the most urgent problems worldwide. The efficient delivery of antimicrobial agents to the site of infection precisely is a promising strategy for reducing bacterial resistance. Polymeric nanomaterials have been widely studied as carriers for constructing antimicrobial agent delivery systems and have shown advantages including high biocompatibility, sustained release, targeting and improved bioavailability. In this review, we will highlight recent advances in highly efficient delivery of antimicrobial agents by polymeric nanomaterials such as micelles, vesicles, dendrimers, nanogels, nanofibers and so forth. The biomedical applications of polymeric nanomaterial-based delivery systems in combating MDR bacteria, anti-biofilms, wound healing, tissue engineering and anticancer are demonstrated. Moreover, conclusions and future perspectives are also proposed.

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Critically important antimicrobial preparations for veterinary medicine

Scientific Messenger of LNU of Veterinary Medicine and Biotechnology ◽

10.15421/nvlvet8704 ◽

2018 ◽

Vol 20 (87) ◽

pp. 19-26 ◽

Cited By ~ 1

Author(s):

T.I. Stetsko ◽

V.P. Muzyka ◽

V.M. Hunchak

Keyword(s):

Veterinary Medicine ◽

Antimicrobial Resistance ◽

Antimicrobial Therapy ◽

Bacterial Infections ◽

Antimicrobial Agents ◽

Animal Health ◽

Point Of View ◽

Animal Origin ◽

European Medicines Agency ◽

Antimicrobial Substances

The resistance of microorganisms, bacterial pathogens, to antimicrobials is a global problem in both healthcare and veterinary medicine. It is believed that the main reason for the emergence and spread of antimicrobial resistance in humans is the transfer of antibiotic resistant strains of microorganisms or genes, determinants of resistance, through products of animal origin from productive animals to humans. Thus, the main way of antimicrobial resistance containment is to restrain and minimize it through the prudent use of antibiotics in veterinary medicine, especially those that are critically important for productive animals. In addition, some classes of antibacterial substances and antibiotics, that are widely used in humane medicine, are used in veterinary medicine. The need to use and preserve these important therapeutic agents is relevant from the point of view of the concept «One Health». The article provides a list of all antibacterial substances used by productive animals for their importance in veterinary medicine, developed by a special group of experts of the World Organisation for Animal Health (OIE). Any antimicrobial agent authorized for use in veterinary medicine for productive animals, in accordance with the criteria for quality, safety and efficacy as defined in Section 6.9 of the Terrestrial Animal Health Code, is considered to be important for veterinary medicine. All the antimicrobial substances used for productive animals are divided in this list on critical, very important and important for veterinary medicine. Attention was also drawn to the peculiarities of the use of critical antimicrobial agents in veterinary medicine, especially those recognized as critical in humane medicine. These include aminoglycosides, cephalosporins of the 3rd and 4th generation, fluoroquinolones, glycopeptides, macrolides, some penicillins and polymyxins. The article also describes the classification of critical antimicrobials by the European Medicines Agency (EMA) and the Panel of Experts on Antimicrobials (AMEG) of the WHO based on the risk profile for humans through the development of antimicrobial resistance after application to productive animals. Such an assessment will give veterinary practitioners an important justification when they make decisions about the clinical treatment of bacterial infections and the responsible appointment of antimicrobial therapy. This will help to reach the balance among the achievement of the effectiveness of antimicrobial therapy of productive animals, reducing of the selective pressure on the development of antibiotic resistance and ensuring of a high level of human health.

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Characterization and Rate of Killing of Conjugated Silver Nanoparticles Against Selected Clinical Bacterial Isolates

10.53365/nrfhh/145339 ◽

2022 ◽

Author(s):

Stephen Oloninefa ◽

Abalaka Moses Enemaduku ◽

Daniyan Saﬁya Yahaya ◽

Mann Abdullahi

Keyword(s):

Drug Delivery ◽

Silver Nanoparticles ◽

Bacterial Infections ◽

Antimicrobial Agents ◽

Silver Ions ◽

Multidrug Resistant ◽

Bacterial Isolates ◽

Target Sites ◽

Alternative Agent ◽

The Fourier Transform

The menace of drug resistance, bioavailability and drug delivery to the target sites has motivated researchers to search for new antimicrobial agents from medicinal plants and subsequently use them for the biosynthesis of silver nanoparticles for effective killing of bacteria challenging to kill using crude extracts. The biosynthesis of silver nanoparticles was done using aqueous extract (AQE) of Euphorbia heterophylla, while characterization and the killing rate of conjugated silver nanoparticles (CAgNPs) were carried out using standard methods. The maximum wavelength obtained for CAgNPs was 410.33 nm, while the size distribution was 237.8 d.nm. The Fourier Transform Infra-Red result showed O-H (3308.94 cm-1), which is responsible for stabilising and reducing silver ions, while the Transmission Electron Microscopy revealed the presence of monodispersed spherical shapes CAgNPs. The Energy Dispersive Spectroscopy confirmed the presence of silver. There were reductions in the clinical bacterial isolates exposed to CAgNPs as the exposure time increased. Escherichia coli was killed between 6-7 h while Salmonella typhimurium was killed at the seven has the value of 0.00 log10 CFU/ml was recorded respectively. However, there were increments in the populations of clinical bacterial isolates in control as the time of exposure increased. Therefore, the study suggests that the CAgNPs exhibit intense antimicrobial activity and the potential to be developed as an alternative agent to treat bacterial infections, curb multidrug-resistant bacterial infection, and promote speedy drug delivery to the target sites.

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Electrospun antibacterial nanofibers for wound dressings and tissue medicinal fields: A Review

Journal of Innovative Optical Health Sciences ◽

10.1142/s1793545820300128 ◽

2020 ◽

Vol 13 (05) ◽

pp. 2030012 ◽

Cited By ~ 1

Author(s):

Zhimei Wei ◽

Liqun Wang ◽

Shouyu Zhang ◽

Tonghai Chen ◽

Jie Yang ◽

...

Keyword(s):

Wound Healing ◽

Biomedical Applications ◽

Bacterial Infections ◽

Antibacterial Agents ◽

Antimicrobial Agents ◽

Electrospinning Process ◽

Wound Dressings ◽

Electrospun Fibers ◽

Chronic Infections ◽

Antibacterial Material

Bacterial infections are a major cause of chronic infections. Thus, antibacterial material is an urgent need in clinics. Antibacterial nanofibers, with expansive surface area, enable efficient incorporation of antibacterial agents. Meanwhile, structure similar to the extracellular matrix can accelerate cell growth. Electrospinning, the most widely used technique to fabricate nanofiber, is often used in many biomedical applications including drug delivery, regenerative medicine, wound healing and so on. Thus, this review provides an overview of all recently published studies on the development of electrospun antibacterial nanofibers in wound dressings and tissue medicinal fields. This reviewer begins with a brief introduction of electrospinning process and then discusses electrospun fibers by incorporating various types of antimicrobial agents used as in wound dressings and tissue. Finally, we finish with conclusions and further perspectives on electrospun antibacterial nanofibers as 2D biomedicine materials.

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Principles of antibiotic therapy

Perspectives in Surgery ◽

10.33699/pis.2019.98.4.137-144 ◽

2019 ◽

Vol 98 (4) ◽

pp. 137-144

Keyword(s):

Antibiotic Therapy ◽

Antibiotic Prophylaxis ◽

Antibiotic Stewardship ◽

Bacterial Infections ◽

Bacterial Resistance ◽

Antimicrobial Agents ◽

Bacterial Pathogens ◽

Comprehensive Approach ◽

Contemporary Medicine ◽

Selection Of

The paper describes the basic sources and principles of antibiotic therapy in contemporary medicine in which the ability to treat bacterial infections may be lost. The main reason for that is the increasing resistance of bacterial pathogens to antibiotics. A possible solution is to implement a comprehensive program of antibiotic stewardship incorporating adequate consideration of indication and selection of antimicrobial agents including appropriate duration and way of administration. Another important component of the comprehensive approach to bacterial resistance and antibiotic therapy is adequately applied antibiotic prophylaxis in surgery.

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DIAGNOSTIC MARKERS IN NEONATAL SEPSIS

Fetal and Maternal Medicine Review ◽

10.1017/s0965539507001866 ◽

2007 ◽

Vol 18 (1) ◽

pp. 53-65

Author(s):

HUGH S. LAM ◽

PAK C NG

Keyword(s):

Bronchopulmonary Dysplasia ◽

Bacterial Infections ◽

Bacterial Resistance ◽

Antimicrobial Agents ◽

Very Low Birth Weight ◽

Late Onset ◽

Significant Proportion ◽

Control Measures ◽

Exogenous Surfactant ◽

Vlbw Infants

Breakthroughs in the management of sick newborns, including exogenous surfactant therapy, advance ventilation techniques, inhaled nitric oxide, and use of antenatal corticosteroids have led to substantial improvements in the survival of vulnerable preterm infants. Neonatal clinicians now have access to an ever increasing armament of antimicrobial agents to help combat infections. However, even with the support of such advanced therapeutic modalities, strict infection control measures and low thresholds for use of broad-spectrum antibiotics, the threat of bacterial infections especially in the most susceptible group of preterm, very low birth weight (VLBW) infants have persisted. A recent survey suggests that a significant proportion of VLBW infants (21%) have at least one episode of late-onset culture proven sepsis during their stay in the neonatal unit. Infected infants require longer hospital stay and have higher risk of developing complications, such as bronchopulmonary dysplasia and adverse long-term neurodevelopment. Neonates with infection often present with subtle and non-specific signs of sepsis. Some may be asymptomatic at the initial stages of infection. Even those infants with signs may not be clinically distinguishable from patients suffering from transient tachypnoea of the newborn, respiratory distress syndrome, apnoea of prematurity or acute exacerbation of bronchopulmonary dysplasia, during early phases of the disease. Such presentations can lead to both delayed treatment of genuinely infected infants and indiscriminate use of antibiotics in non-infected cases, resulting in acceleration of emergence of bacterial resistance, alteration of patterns of bacterial infection, and inefficient treatment of septicaemia. Both early and late-onset infections are important causes of neonatal morbidity and mortality. Methods to assist neonatal clinicians diagnose infants in the early stages of infection are, therefore, highly desirable.

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Antimicrobial Gold Nanoclusters: Recent Developments and Future Perspectives

International Journal of Molecular Sciences ◽

10.3390/ijms20122924 ◽

2019 ◽

Vol 20 (12) ◽

pp. 2924 ◽

Cited By ~ 21

Author(s):

Sibidou Yougbare ◽

Ting-Kuang Chang ◽

Shih-Hua Tan ◽

Jui-Chi Kuo ◽

Po-Hsuan Hsu ◽

...

Keyword(s):

Small Molecules ◽

Biomedical Applications ◽

Bacterial Infections ◽

Antimicrobial Agents ◽

Gold Nanoclusters ◽

Antimicrobial Activities ◽

Future Perspectives ◽

Structural And Optical Properties ◽

Surface Ligands ◽

Recent Developments

Bacterial infections have caused serious threats to public health due to the antimicrobial resistance in bacteria. Recently, gold nanoclusters (AuNCs) have been extensively investigated for biomedical applications because of their superior structural and optical properties. Great efforts have demonstrated that AuNCs conjugated with various surface ligands are promising antimicrobial agents owing to their high biocompatibility, polyvalent effect, easy modification and photothermal stability. In this review, we have highlighted the recent achievements for the utilizations of AuNCs as the antimicrobial agents. We have classified the antimicrobial AuNCs by their surface ligands including small molecules (<900 Daltons) and macromolecules (>900 Daltons). Moreover, the antimicrobial activities and mechanisms of AuNCs have been introduced into two main categories of small molecules and macromolecules, respectively. In accordance with the advancements of antimicrobial AuNCs, we further provided conclusions of current challenges and recommendations of future perspectives of antimicrobial AuNCs for fundamental researches and clinical applications.

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Multidrug-Resistant Acinetobacter baumannii Genetic Characterization and Spread in Lithuania in 2014, 2016, and 2018

Life ◽

10.3390/life11020151 ◽

2021 ◽

Vol 11 (2) ◽

pp. 151

Author(s):

Tatjana Kirtikliene ◽

Aistė Mierauskaitė ◽

Ilona Razmienė ◽

Nomeda Kuisiene

Keyword(s):

Acinetobacter Baumannii ◽

Resistance Genes ◽

Bacterial Infections ◽

Bacterial Resistance ◽

Antimicrobial Agents ◽

Variable Number Tandem Repeat ◽

Multidrug Resistant ◽

Resistant Bacteria ◽

Essential Information ◽

Acinetobacter Spp

Bacterial resistance to antimicrobial agents plays an important role in the treatment of bacterial infections in healthcare institutions. The spread of multidrug-resistant bacteria can occur during inter- and intra-hospital transmissions among patients and hospital personnel. For this reason, more studies must be conducted to understand how resistance occurs in bacteria and how it moves between hospitals by comparing data from different years and looking out for any patterns that might emerge. Multidrug-resistant (MDR) Acinetobacter spp. was studied at 14 healthcare institutions in Lithuania during 2014, 2016, and 2018 using samples from human bloodstream infections. In total, 194 isolates were collected and identified using MALDI-TOF and VITEK2 analyzers as Acinetobacter baumannii group bacteria. After that, the isolates were analyzed for the presence of different resistance genes (20 genes were analyzed) and characterized by using the Rep-PCR and MLVA (multiple-locus variable-number tandem repeat analysis) genotyping methods. The results of the study showed the relatedness of the different Acinetobacter spp. isolates and a possible circulation of resistance genes or profiles during the different years of the study. This study provides essential information, such as variability and diversity of resistance genes, genetic profiling, and clustering of isolates, to better understand the antimicrobial resistance patterns of Acinetobacter spp. These results can be used to strengthen the control of multidrug-resistant infections in healthcare institutions and to prevent potential outbreaks of this pathogen in the future.

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Antimicrobial applications of nanoliposome encapsulated silver nanoparticles: a potential strategy to overcome bacterial resistance

Current Nanoscience ◽

10.2174/1573413716999200712184148 ◽

2020 ◽

Vol 16 ◽

Author(s):

M.R. Mozafari ◽

Sarabanou Torkaman ◽

Fatemeh Mahsa Karamouzian ◽

Babak Rasti ◽

Bikash Baral

Keyword(s):

Silver Nanoparticles ◽

Bacterial Infections ◽

Bacterial Resistance ◽

Water Soluble ◽

Severe Illness ◽

Efficient System ◽

Antimicrobial Substances ◽

Potential Strategy

: Bacterial infections result in hundreds of million cases of severe illness annually worldwide. Rapidly increasing drug resistance of pathogens further aggravates this threat to human health and warrants the search for effective broadspectrum antibacterial agents. Silver metal has a long history of application in human medicine and healthcare. In ancient times, silver was employed as a disinfectant for water purification and storage while it is still being used as an antimicrobial ingredient in some nanotechnology-based products. Encapsulation of antimicrobial substances such as silver nanoparticles in nanoliposomes could provide protection and targeting for the encapsulated or entrapped material. Nanoliposomes are biocompatible and biodegradable drug delivery systems with the ability to encapsulate both lipidsoluble and water-soluble compounds, as well as metal ions. Furthermore, nanoliposomes have been shown to be able to deliver encapsulated agents to target bacteria in vitro as well as in vivo. In this review, we present the use of nanoliposome-encapsulated silver nanoparticles as an efficient system for antibacterial applications.

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Synergism between Host Defence Peptides and Antibiotics Against Bacterial Infections

Current Topics in Medicinal Chemistry ◽

10.2174/1568026620666200303122626 ◽

2020 ◽

Vol 20 (14) ◽

pp. 1238-1263 ◽

Cited By ~ 1

Author(s):

Jiarui Li ◽

Pablo Fernández-Millán ◽

Ester Boix

Keyword(s):

Bacterial Infections ◽

Bacterial Resistance ◽

Antimicrobial Agents ◽

Resistance Mechanisms ◽

Adjuvant Activity ◽

Biofilm Growth ◽

Intracellular Target ◽

Conventional Antibiotics ◽

Available Information ◽

Toxic Concentrations

Background: Antimicrobial resistance (AMR) to conventional antibiotics is becoming one of the main global health threats and novel alternative strategies are urging. Antimicrobial peptides (AMPs), once forgotten, are coming back into the scene as promising tools to overcome bacterial resistance. Recent findings have attracted attention to the potentiality of AMPs to work as antibiotic adjuvants. Methods: In this review, we have tried to collect the currently available information on the mechanism of action of AMPs in synergy with other antimicrobial agents. In particular, we have focused on the mechanisms of action that mediate the inhibition of the emergence of bacterial resistance by AMPs. Results and Conclusion: We find in the literature many examples where AMPs can significantly reduce the antibiotic effective concentration. Mainly, the peptides work at the bacterial cell wall and thereby facilitate the drug access to its intracellular target. Complementarily, AMPs can also contribute to permeate the exopolysaccharide layer of biofilm communities, or even prevent bacterial adhesion and biofilm growth. Secondly, we find other peptides that can directly block the emergence of bacterial resistance mechanisms or interfere with the community quorum-sensing systems. Interestingly, the effective peptide concentrations for adjuvant activity and inhibition of bacterial resistance are much lower than the required for direct antimicrobial action. Finally, many AMPs expressed by innate immune cells are endowed with immunomodulatory properties and can participate in the host response against infection. Recent studies in animal models confirm that AMPs work as adjuvants at non-toxic concentrations and can be safely administrated for novel combined chemotherapies.

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PROPAGATION OF ANTIMICROBIAL RESISTANT Salmonella spp. IN BIVALVE MOLLUSKS FROM ESTUARY AREAS OF BAHIA, BRAZIL

Revista Caatinga ◽

10.1590/1983-21252016v29n222rc ◽

2016 ◽

Vol 29 (2) ◽

pp. 450-457 ◽

Cited By ~ 3

Author(s):

CARLA SILVA DA SILVEIRA ◽

OSCARINA VIANA DE SOUSA ◽

NORMA SUELY EVANGELISTA-BARRETO

Keyword(s):

Nalidixic Acid ◽

Bacterial Infections ◽

Bacterial Resistance ◽

Antimicrobial Agents ◽

Resistance Index ◽

Multidrug Resistant ◽

Resistance Mechanisms ◽

Bivalve Mollusks ◽

Salmonella Spp ◽

Development Of Resistance

ABSTRACT: In recent years, the emergence of resistant pathogens has complicated the treatment of bacterial infections in livestock production as well as in the medical field, due to the development of resistance mechanisms by microorganisms. The objective of this study was to delineate the antimicrobial resistance profile of Salmonella spp. strains isolated from bivalve mollusks (oysters and mussels) and from estuarine environment water of two regions of Bahia, Brazil. Twenty-seven strains, 12 isolated from bivalve mollusks and 15 from estuarine water, were tested. Eight antimicrobial agents (phenicol, beta-lactams, tetracyclines, quinolones and fluoroquinolones classes) were used for a susceptibility test, Minimum Inhibitory Concentration (MIC) and extended-spectrum beta-lactamases (ESBLs) production. Isolates showed high susceptibility to the classes of antimicrobial agents tested, with resistance only to nalidixic acid (27%), ampicillin (25%) and tetracycline (25%). Bacterial resistance was of chromosomal origin and the multidrug resistance index (MAR) among isolates of shellfish (mussels in natura) was 0.25. The MIC was found to be 100 µg/mL, 500 µg/mL and 350 µg/mL to nalidixic acid, ampicillin and tetracycline, respectively. None of the isolates presented ESBLs production. The presence of multidrug-resistant and high MIC Salmonella spp. is being conveyed in extraction areas of bivalve mollusks in the State of Bahia, Brazil.

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