scholarly journals Nanomaterials as Delivery Vehicles and Components of New Strategies to Combat Bacterial Infections: Advantages and Limitations

2019 ◽  
Vol 7 (9) ◽  
pp. 356 ◽  
Author(s):  
Atanu Naskar ◽  
Kwang-sun Kim

Life-threatening bacterial infections have been well-controlled by antibiotic therapies and this approach has greatly improved the health and lifespan of human beings. However, the rapid and worldwide emergence of multidrug resistant (MDR) bacteria has forced researchers to find alternative treatments for MDR infections as MDR bacteria can sometimes resist all the present day antibiotic therapies. In this respect, nanomaterials have emerged as innovative antimicrobial agents that can be a potential solution against MDR bacteria. The present review discusses the advantages of nanomaterials as potential medical means and carriers of antibacterial activity, the types of nanomaterials used for antibacterial agents, strategies to tackle toxicity of nanomaterials for clinical applications, and limitations which need extensive studies to overcome. The current progress of using different types of nanomaterials, including new emerging strategies for the single purpose of combating bacterial infections, is also discussed in detail.

Author(s):  
Chockaiyan Usha ◽  
Pandi Sakthieaswari ◽  
Parameswaran Kiruthika Lakshmi

Antibiotic therapy for life-threatening bacterial infections has greatly enhanced the lifespan and health of human beings. But continued increase in the improper usage of antibiotics and emergence of multidrug resistant bacteria (MDR) remains a major reason for the morbidity and mortality worldwide. Delay in the detection of pathogens, poor penetration power of the antimicrobial agent, and susceptibility for mutational resistance also resulted in clinical failure of conventional antibiotics. Innovation of nanoparticles (NPs) serves as a promising strategy to overcome MDR bacteria. The site-specific action of NPs, high penetration power, minimal dosage, and multidimensional mechanism makes NPs highly efficient to tackle MDR bacteria than conventional drugs. This chapter presents a brief overview on various types of NPs, strategies to combat drug resistance, mode of action of NPs as antibacterial agents, applicability in various medical fields, clinical manifestation, challenges in clinical translation, and future prospects.


2018 ◽  
Vol 115 (51) ◽  
pp. 12887-12895 ◽  
Author(s):  
Stephen J. Baker ◽  
David J. Payne ◽  
Rino Rappuoli ◽  
Ennio De Gregorio

Bacterial infections have been traditionally controlled by antibiotics and vaccines, and these approaches have greatly improved health and longevity. However, multiple stakeholders are declaring that the lack of new interventions is putting our ability to prevent and treat bacterial infections at risk. Vaccine and antibiotic approaches still have the potential to address this threat. Innovative vaccine technologies, such as reverse vaccinology, novel adjuvants, and rationally designed bacterial outer membrane vesicles, together with progress in polysaccharide conjugation and antigen design, have the potential to boost the development of vaccines targeting several classes of multidrug-resistant bacteria. Furthermore, new approaches to deliver small-molecule antibacterials into bacteria, such as hijacking active uptake pathways and potentiator approaches, along with a focus on alternative modalities, such as targeting host factors, blocking bacterial virulence factors, monoclonal antibodies, and microbiome interventions, all have potential. Both vaccines and antibacterial approaches are needed to tackle the global challenge of antimicrobial resistance (AMR), and both areas have the underpinning science to address this need. However, a concerted research agenda and rethinking of the value society puts on interventions that save lives, by preventing or treating life-threatening bacterial infections, are needed to bring these ideas to fruition.


2017 ◽  
Vol 63 (11) ◽  
pp. 865-879 ◽  
Author(s):  
Ayman El-Shibiny ◽  
Salma El-Sahhar

Since their discovery in 1915, bacteriophages have been used to treat bacterial infections in animals and humans because of their unique ability to infect their specific bacterial hosts without affecting other bacterial populations. The research carried out in this field throughout the 20th century, largely in Georgia, part of USSR and Poland, led to the establishment of phage therapy protocols. However, the discovery of penicillin and sulfonamide antibiotics in the Western World during the 1930s was a setback in the advancement of phage therapy. The misuse of antibiotics has reduced their efficacy in controlling pathogens and has led to an increase in the number of antibiotic-resistant bacteria. As an alternative to antibiotics, bacteriophages have become a topic of interest with the emergence of multidrug-resistant bacteria, which are a threat to public health. Recent studies have indicated that bacteriophages can be used indirectly to detect pathogenic bacteria or directly as biocontrol agents. Moreover, they can be used to develop new molecules for clinical applications, vaccine production, drug design, and in the nanomedicine field via phage display.


Author(s):  
Na Li ◽  
Yigang Zeng ◽  
Rong Bao ◽  
Tongyu Zhu ◽  
Demeng Tan ◽  
...  

Klebsiella pneumoniae is a dominant cause of community-acquired and nosocomial infections, specifically among immunocompromised individuals. The increasing occurrence of multidrug-resistant (MDR) isolates has significantly impacted the effectiveness of antimicrobial agents. As antibiotic resistance is becoming increasingly prevalent worldwide, the use of bacteriophages to treat pathogenic bacterial infections has recently gained attention. Elucidating the details of phage-bacteria interactions will provide insights into phage biology and the better development of phage therapy. In this study, a total of 22 K. pneumoniae isolates were assessed for their genetic and phenotypic relatedness by multi-locus sequence typing (MLST), endonuclease S1 nuclease pulsed-field gel electrophoresis (S1-PFGE), and in vitro antibiotic susceptibility testing. In addition, the beta-lactamase gene (blaKPC) was characterized to determine the spread and outbreak of K. pneumoniae carbapenemase (KPC)-producing enterobacterial pathogens. Using these ST11 carbapenem-resistant K. pneumoniae isolates, three phages (NL_ZS_1, NL_ZS_2, and NL_ZS_3) from the family of Podoviridae were isolated and characterized to evaluate the application of lytic phages against the MDR K. pneumoniae isolates. In vitro inhibition assays with three phages and K. pneumoniae strain ZS15 demonstrated the strong lytic potential of the phages, however, followed by the rapid growth of phage-resistant and phage-sensitive mutants, suggesting several anti-phage mechanisms had developed in the host populations. Together, this data adds more comprehensive knowledge to known phage biology and further emphasizes their complexity and future challenges to overcome prior to using phages for controlling this important MDR bacterium.


2020 ◽  
Vol 8 (2) ◽  
pp. 191 ◽  
Author(s):  
Despoina Koulenti ◽  
Elena Xu ◽  
Andrew Song ◽  
Isaac Yin Sum Mok ◽  
Drosos E. Karageorgopoulos ◽  
...  

Antimicrobial agents are currently the mainstay of treatment for bacterial infections worldwide. However, due to the increased use of antimicrobials in both human and animal medicine, pathogens have now evolved to possess high levels of multi-drug resistance, leading to the persistence and spread of difficult-to-treat infections. Several current antibacterial agents active against Gram-positive bacteria will be rendered useless in the face of increasing resistance rates. There are several emerging antibiotics under development, some of which have been shown to be more effective with an improved safety profile than current treatment regimens against Gram-positive bacteria. We will extensively discuss these antibiotics under clinical development (phase I-III clinical trials) to combat Gram-positive bacteria, such as Staphylococcus aureus, Enterococcus faecium and Streptococcus pneumoniae. We will delve into the mechanism of actions, microbiological spectrum, and, where available, the pharmacokinetics, safety profile, and efficacy of these drugs, aiming to provide a comprehensive review to the involved stakeholders.


2018 ◽  
Vol 12 (2) ◽  
pp. 12-20
Author(s):  
N. A. Korobkov ◽  
N. N. Volkov ◽  
E. R. Tsoy ◽  
S. М. Mikaelyan

The number of patients with nosocomial post-cesarean endometritis is steadily growing. Aim: to study the etiology of nosocomial post-cesarean endometritis and to propose a rationalized antimicrobial therapy. Material and methods. Sixty six puerperas with post-cesarean endometritis were examined. The spectrum of microflora and its resistance to antimicrobial agents were determined using an automatic microbiological analyzer based on mass spectrometry. Results. Enterococci, E. coli, staphylococci and streptococci were the most clinically significant pathogens found in the examined patients with post-cesarean endometritis. The microflora spectrum in the endometrium reflected the previous «antibacterial history»; this association must be taken into account when developing antibacterial therapy. Conclusion. If the new mother was previously treated with antibacterial agents, it is recommended to use a combination of the reserve antibiotics in order to block the entire spectrum of possible multidrug-resistant pathogens. In cases of the resistant Gram-positive microflora (MRSE, MRSA, E. faecium), it is advisable to prescribe vancomycin. For the resistant Gram-negative microflora (Enterobacter spp., Citrobacter spp., E. coli-ESBL+ and Klebsiella spp.-ESBL+), vancomycin should be combined with carbapenems.


2018 ◽  
Vol 87 (4) ◽  
pp. 181-187 ◽  
Author(s):  
N. Vander Elst ◽  
E. Meyer

The increase in bacterial drug resistance causes major difficulties in the clinical treatment of a growing number of bacterial infections worldwide. Consequently, there is an urgent need to develop novel anti-bacterial agents to control these resistant pathogens and to complement the currently used antibiotics. Mastitis is the most prevalent disease impacting dairy cattle, and therefore one of the costliest diseases in the global dairy industry. The excessive use of curative as well as preventive antibiotics in this sector entails a real risk for the emergence of antimicrobial resistance. Moreover, these traditional antimicrobial agents are often ineffective and lead to residues in the milk, which can affect dairy product consumers. As an alternative therapeutic approach, bacteriophages and phage-encoded endolysins have been proposed and are currently (re)investigated as potential antibacterial agents against mastitis.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2108
Author(s):  
Yin Wang ◽  
Hui Sun

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.


2022 ◽  
Author(s):  
Stephen Oloninefa ◽  
Abalaka Moses Enemaduku ◽  
Daniyan Safiya Yahaya ◽  
Mann Abdullahi

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 E<i>uphorbia heterophylla</i>, while characterization and the killing rate of conjugated silver nanoparticles (CA<sub>g</sub>NP<sub>s</sub>) were carried out using standard methods. The maximum wavelength obtained for CA<sub>g</sub>NP<sub>s</sub> 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<sup>-1</sup>), which is responsible for stabilising and reducing silver ions, while the Transmission Electron Microscopy revealed the presence of monodispersed spherical shapes CA<sub>g</sub>NP<sub>s</sub>. The Energy Dispersive Spectroscopy confirmed the presence of silver. There were reductions in the clinical bacterial isolates exposed to CA<sub>g</sub>NP<sub>s</sub> as the exposure time increased. <i>Escherichia coli</i> was killed between 6-7 h while<i> Salmonella typhimurium</i> was killed at the seven has the value of 0.00 log<sub>10</sub> 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 CA<sub>g</sub>NP<sub>s</sub> 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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