scholarly journals Bacteriophage Structure, Classification, Assembly and Phage Therapy

2021 ◽  
Vol 18 (2) ◽  
pp. 239-250
Author(s):  
Nabanita Giri
Keyword(s):  
Bacterial Infections ◽  
Bacterial Species ◽  
Multidrug Resistant ◽  
The Other ◽  
Basic Knowledge ◽  
New Antibiotics ◽  
Associated Proteins ◽  
Conventional Antibiotics ◽  
And Function ◽  
Structure Configuration

Current emergence of multidrug resistance and limitations in the development of the new antibiotics has proposed the problem of treating bacterial infections more challenging. This scenario may lead to the fear of failure in treating the multidrug resistant (MDR) bacterial infections and fuelled the uses of bacteriophages as an alternative of the conventional antibiotics in the post antibiotic era.So it is very much essential to know about the details of phage life cycle, assembly of phage complete structure, configuration and function of phage associated proteins etc. Although phages have been discovered a century ego, detailed study about lytic phages are gaining more interest in global fight against MDR bacterial species. This review has highlighted the basic knowledge of bacteriophage with the past and present scenario of several clinical studies targeting the MDR bacterial species. On the other hand it also discussed about the other uses of phages except human clinical trials.

scholarly journals Clinically relevant infections in hematology and oncology: bacterial infections and the role of novel antibiotics in times of multidrug resistance

2021 ◽  
Author(s):  
Gernot Fritsche
Keyword(s):  
Multidrug Resistance ◽  
Antibiotic Therapy ◽  
Bacterial Infections ◽  
Empirical Therapy ◽  
Multidrug Resistant ◽  
Infectious Complications ◽  
Novel Drugs ◽  
New Antibiotics ◽  
Conventional Antibiotics ◽  
Novel Antibiotics

SummaryMultidrug resistance of bacterial pathogens is an increasing problem wordwide, especially treatment of multidrug resistant (MDR) gramnegative bacteria is challenging. In the recent past, several new antibiotics as well as new betalactamase inhibitors have been introduced. These novel drugs are valuable new tools for the therapy of infectious complications in cancer patients once there is a high risk for infections due to multidrug-resistant pathogens. While it is necessary to start empirical antibiotic therapy immediately, novel antibiotics only provide benefits in certain situations, depending on the underlying pathogens. Thus, these new antibiotics are best used guided by microbiological testing, since the exact mechanism of resistance determines susceptibility or resistance to certain antibiotics. For empirical therapy, previous culture results and/or colonization with MDR pathogens can help to choose from conventional antibiotics or novel drugs. In clinical practice, optimal antibiotic therapy can be achieved by close collaboration of specialists in hematooncology, infectious diseases and microbiology.

Linear plasmids in Klebsiella and other Enterobacteriaceae

2021 ◽  
Author(s):  
Jane Hawkey ◽  
Hugh Cottingham ◽  
Alex Tokolyi ◽  
Ryan R Wick ◽  
Louise M Judd ◽  
...  
Keyword(s):  
Plasmid Stability ◽  
Bacterial Species ◽  
Salmonella Typhi ◽  
Multidrug Resistant ◽  
Linear Plasmid ◽  
Extrachromosomal Dna ◽  
Linear Plasmids ◽  
Future Studies ◽  
And Function

Linear plasmids are extrachromosomal DNA that have been found in a small number of bacterial species. To date, the only linear plasmids described in the Enterobacteriaceae family belong to Salmonella, first found in Salmonella Typhi. Here, we describe a collection of 12 isolates of the Klebsiella pneumoniae species complex in which we identified linear plasmids. We used this collection to search public sequence databases and discovered an additional 74 linear plasmid sequences in a variety of Enterobacteriaceae species. Gene content analysis divided these plasmids into five distinct phylogroups, with very few genes shared across more than two phylogroups. The majority of linear plasmid-encoded genes are of unknown function, however each phylogroup carried its own unique toxin-antitoxin system and genes with homology to those encoding the ParAB plasmid stability system. Passage in vitro of the 12 linear plasmid-carrying Klebsiella isolates in our collection (which include representatives of all five phylogroups) indicated that these linear plasmids can be stably maintained, and our data suggest they can transmit between K. pneumoniae strains (including members of globally disseminated multidrug resistant clones) and also between diverse Enterobacteriaceae species. The linear plasmid sequences, and representative isolates harbouring them, are made available as a resource to facilitate future studies on the evolution and function of these novel plasmids.

scholarly journals Loxosceles gaucho Spider Venom: An Untapped Source of Antimicrobial Agents

Toxins ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 522 ◽  
Author(s):  
Paula Segura-Ramírez ◽  
Pedro Silva Júnior
Keyword(s):  
Bacterial Infections ◽  
High Performance ◽  
Antimicrobial Agents ◽  
Chemical Properties ◽  
Carcinoma Cells ◽  
Promising Candidate ◽  
Human Red Blood Cells ◽  
New Antibiotics ◽  
Conventional Antibiotics ◽  
Human Cervical Carcinoma Cells

The remarkable ability of microorganisms to develop resistance to conventional antibiotics is one of the biggest challenges that the pharmaceutical industry currently faces. Recent studies suggest that antimicrobial peptides discovered in spider venoms may be useful resources for the design of structurally new anti-infective agents effective against drug-resistant microorganisms. In this work, we found an anionic antibacterial peptide named U1-SCRTX-Lg1a in the venom of the spider Loxosceles gaucho. The peptide was purified using high-performance liquid chromatography (HPLC), its antimicrobial activity was tested through liquid growth inhibition assays, and its chemical properties were characterized using mass spectrometry. U1-SCRTX-Lg1a was found to show a monoisotopic mass of 1695.75 Da, activity against Gram-negative bacteria, a lack of hemolytic effects against human red blood cells, and a lack of cytotoxicity against human cervical carcinoma cells (HeLa). Besides this, the sequence of the peptide exhibited great similarity to specific regions of phospholipases D from different species of Loxosceles spiders, leading to the hypothesis that U1-SCRTX-Lg1a may have originated from a limited proteolytic cleavage. Our data suggest that U1-SCRTX-Lg1a is a promising candidate for the development of new antibiotics that could help fight bacterial infections and represents an exciting discovery for Loxosceles spiders.

scholarly journals Protein–protein interactions in bacteria: a promising and challenging avenue towards the discovery of new antibiotics

2018 ◽  
Vol 14 ◽  
pp. 2881-2896 ◽  
Author(s):  
Laura Carro
Keyword(s):  
Protein Interactions ◽  
Bacterial Infections ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Protein Protein Interactions ◽  
Lead Discovery ◽  
Antibiotic Development ◽  
Cellular Processes ◽  
Ppi Networks ◽  
New Antibiotics

Antibiotics are potent pharmacological weapons against bacterial infections; however, the growing antibiotic resistance of microorganisms is compromising the efficacy of the currently available pharmacotherapies. Even though antimicrobial resistance is not a new problem, antibiotic development has failed to match the growth of resistant pathogens and hence, it is highly critical to discover new anti-infective drugs with novel mechanisms of action which will help reducing the burden of multidrug-resistant microorganisms. Protein–protein interactions (PPIs) are involved in a myriad of vital cellular processes and have become an attractive target to treat diseases. Therefore, targeting PPI networks in bacteria may offer a new and unconventional point of intervention to develop novel anti-infective drugs which can combat the ever-increasing rate of multidrug-resistant bacteria. This review describes the progress achieved towards the discovery of molecules that disrupt PPI systems in bacteria for which inhibitors have been identified and whose targets could represent an alternative lead discovery strategy to obtain new anti-infective molecules.

scholarly journals Antimicrobial Effects of Biogenic Nanoparticles

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1009 ◽  
Author(s):  
Priyanka Singh ◽  
Abhroop Garg ◽  
Santosh Pandit ◽  
V. Mokkapati ◽  
Ivan Mijakovic
Keyword(s):  
Infectious Diseases ◽  
Metallic Nanoparticles ◽  
Active Surface ◽  
Multidrug Resistant ◽  
Antimicrobial Drugs ◽  
Long Term Stability ◽  
New Antibiotics ◽  
Conventional Antibiotics ◽  
Biogenic Nanoparticles

Infectious diseases pose one of the greatest health challenges in the medical world. Though numerous antimicrobial drugs are commercially available, they often lack effectiveness against recently developed multidrug resistant (MDR) microorganisms. This results in high antibiotic dose administration and a need to develop new antibiotics, which in turn requires time, money, and labor investments. Recently, biogenic metallic nanoparticles have proven their effectiveness against MDR microorganisms, individually and in synergy with the current/conventional antibiotics. Importantly, biogenic nanoparticles are easy to produce, facile, biocompatible, and environmentally friendly in nature. In addition, biogenic nanoparticles are surrounded by capping layers, which provide them with biocompatibility and long-term stability. Moreover, these capping layers provide an active surface for interaction with biological components, facilitated by free active surface functional groups. These groups are available for modification, such as conjugation with antimicrobial drugs, genes, and peptides, in order to enhance their efficacy and delivery. This review summarizes the conventional antibiotic treatments and highlights the benefits of using nanoparticles in combating infectious diseases.

scholarly journals Cockroaches as a Source of High Bacterial Pathogens with Multidrug Resistant Strains in Gondar Town, Ethiopia

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Feleke Moges ◽  
Setegn Eshetie ◽  
Mengistu Endris ◽  
Kahsay Huruy ◽  
Dagnachew Muluye ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Bacterial Species ◽  
Multidrug Resistant ◽  
Resistance Rate ◽  
Control Measures ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Gondar Town ◽  
Resistant Strains ◽  
And Control

Background. Cockroaches are source of bacterial infections and this study was aimed to assess bacterial isolates and their antimicrobial profiles from cockroaches in Gondar town, Ethiopia.Methods. A total of 60 cockroaches were collected from March 1 to May 30, 2014, in Gondar town. Bacterial species were isolated from external and internal parts of cockroaches. Disk diffusion method was used to determine antibiotic susceptibility patterns. Data were entered and analyzed by using SPSS version 20;Pvalues <0.005 were considered as statistically significant.Results. Of 181 identified bacteria species, 110 (60.8%) and 71 (39.2%) were identified from external and internal parts of cockroaches, respectively.Klebsiella pneumoniae32 (17.7%),Escherichia coli29 (16%), andCitrobacterspp. 27 (15%) were the predominant isolates. High resistance rate was observed to cotrimoxazole, 60 (33.1%), and least resistance rate was noted to ciprofloxacin, 2 (1.1%). Additionally, 116 (64.1%) of the isolates were MDR strains;Salmonellaspp. were the leading MDR isolates (100%) followed byEnterobacter(90.5%) andShigellaspp. (76.9%).Conclusion. Cockroaches are the potential source of bacteria pathogens with multidrug resistant strains and hence effective preventive and control measures are required to minimize cockroach related infections.

scholarly journals Antibacterial and potentiation properties of charge-optimized polyrotaxanes for combating opportunistic bacteria

2018 ◽  
Vol 6 (33) ◽  
pp. 5353-5361 ◽  
Author(s):  
Jing Qiao ◽  
Zhi Liu ◽  
Max Purro ◽  
May P. Xiong
Keyword(s):  
Bacterial Infections ◽  
Multidrug Resistant ◽  
Opportunistic Bacteria ◽  
Conventional Antibiotics

Bacteria are now becoming more resistant to most conventional antibiotics. Approaches for the treatment of multidrug-resistant bacterial infections are urgently required.

scholarly journals Metabolic profiling and antibacterial activity of Eryngium pristis Cham. & Schltdl. - prospecting for its use in the treatment of bacterial infections

2021 ◽  
Vol 5 (1) ◽  
pp. 020-028
Author(s):  
Fernandes Laura Silva ◽  
da Costa Ygor Ferreira Garcia ◽  
de Bessa Martha Eunice ◽  
Ferreira Adriana Lucia Pires ◽  
do Amaral Corrêa José Otávio ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Bioactive Compounds ◽  
Metabolic Profile ◽  
Bacterial Infections ◽  
Ethanolic Extract ◽  
Multidrug Resistant ◽  
Gas Chromatography Mass Spectrometry ◽  
Resistant Bacteria ◽  
Bacterial Strains ◽  
New Antibiotics

Morbidity and mortality of the infected patients by multidrug-resistant bacteria have increased, emphasizing the urgency of fight for the discovery of new innovative antibiotics. In this sense, natural products emerge as valuable sources of bioactive compounds. Among the biodiversity, Eryngium pristis Cham. & Schltdl. (Apiaceae Lindl.) is traditionally used to treat thrush and ulcers of throat and mouth, as diuretic and emmenagogue, but scarcely known as an antimicrobial agent. With this context in mind, the goals of this study were to investigate the metabolic profile and the antibacterial activity of ethanolic extract (EE-Ep) and hexane (HF-Ep), dichloromethane (DF-Ep), ethyl acetate (EAF-Ep) and butanol (BF-Ep) fractions from E. pristis leaves. Gas Chromatography-Mass Spectrometry (GC-MS) was performed to stablish the metabolic profile and revealed the presence of 12 and 14 compounds in EAF-Ep and HF-Ep, respectively. β-selinene, spathulenol, globulol, 2-methoxy-4-vinylphenol, α-amyrin, β-amyrin, and lupeol derivative were some of phytochemicals identified. The antibacterial activity was determined by Minimal Inhibitory Concentration (MIC) using the broth micro-dilution against eight ATCC® and five methicillin-resistant Staphylococcus aureus (MRSA) clinical strains. HF-Ep was the most effective (MIC ≤ 5,000 µg/µL), being active against the largest part of tested Gram-positive and Gram-negative bacterial strains, including MRSA, with exception of Escherichia coli (ATCC 25922) and Pseudomonas aeruginosa (ATCC 9027) and (ATCC 27853). These results suggest that E. pristis is a natural source of bioactive compounds for the search of new antibiotics which can be an interesting therapeutic approach to recover patients mainly infected by MRSA strains.

scholarly journals Design, Overproduction and Purification of the Chimeric Phage Lysin MLTphg Fighting against Staphylococcus aureus

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1587
Author(s):  
Feng Wang ◽  
Xiaohang Liu ◽  
Zhengyu Deng ◽  
Yao Zhang ◽  
Xinyu Ji ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Conventional Antibiotics ◽  
Phage Lysin ◽  
Shed Light

With the increasing spread of multidrug-resistant bacterial pathogens, it is of great importance to develop alternatives to conventional antibiotics. Here, we report the generation of a chimeric phage lysin, MLTphg, which was assembled by joining the lysins derived from Meiothermus bacteriophage MMP7 and Thermus bacteriophage TSP4 with a flexible linker via chimeolysin engineering. As a potential antimicrobial agent, MLTphg can be obtained by overproduction in Escherichia coli BL21(DE3) cells and the following Ni-affinity chromatography. Finally, we recovered about 40 ± 1.9 mg of MLTphg from 1 L of the host E. coli BL21(DE3) culture. The purified MLTphg showed peak activity against Staphylococcus aureus ATCC6538 between 35 and 40 °C, and maintained approximately 44.5 ± 2.1% activity at room temperature (25 °C). Moreover, as a produced chimera, it exhibited considerably improved bactericidal activity against Staphylococcus aureus (2.9 ± 0.1 log10 reduction was observed upon 40 nM MLTphg treatment at 37 °C for 30 min) and also a group of antibiotic-resistant bacteria compared to its parental lysins, TSPphg and MMPphg. In the current age of growing antibiotic resistance, our results provide an engineering basis for developing phage lysins as novel antimicrobial agents and shed light on bacteriophage-based strategies to tackle bacterial infections.

scholarly journals Deimmunized Lysostaphin Synergizes with Small-molecule Chemotherapies and Re-sensitizes MRSA to β-Lactam Antibiotics

2020 ◽  
pp. AAC.01707-20
Author(s):  
Yongliang Fang ◽  
Jack R. Kirsch ◽  
Liang Li ◽  
Seth A. Brooks ◽  
Spencer Heim ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Standard Of Care ◽  
Rapid Onset ◽  
Multidrug Resistant ◽  
Genetically Engineered ◽  
High Potency ◽  
Onset Of Action ◽  
New Antibiotics

There is an urgent need for novel agents to treat drug-resistant bacterial infections, such as multidrug-resistant Staphylococcus aureus (MRSA). Desirable properties for new antibiotics include high potency, narrow species selectivity, low propensity to elicit new resistance phenotypes, and synergy with standard of care (SOC) chemotherapies. Here, we describe analysis of the anti-MRSA potential exhibited by F12, an innovative anti-MRSA lysin that has been genetically engineered to evade detrimental antidrug immune responses in human patients. F12 possesses high potency and rapid onset of action, it has narrow selectivity against pathogenic Staphylococci, and it manifests synergy with numerous SOC antibiotics. Additionally, resistance to F12 and β-lactam antibiotics appears mutually exclusive, and importantly we provide evidence that F12 re-sensitizes normally resistant MRSA strains to β-lactams both in vitro and in vivo. These results suggest that combinations of F12 and SOC antibiotics could be a promising new approach to treating refractory S. aureus infections.

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