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Green Metal-Based Nanoparticles Synthesized Using Medicinal Plants and Plant Phytochemicals against Multidrug-Resistant Staphylococcus aureus
Published in Richard L. K. Glover, Daniel Nyanganyura, Rofhiwa Bridget Mulaudzi, Maluta Steven Mufamadi, Green Synthesis in Nanomedicine and Human Health, 2021
Abeer Ahmed Qaed Ahmed, Lin Xiao, Tracey Jill Morton McKay, Guang Yang
Many infectious diseases, including S. aureus, became curable due to antibiotics. However, the treatment of S. aureus infections is complex as S. aureus can acquire resistance to antibiotics due to mobile genetic elements (MGEs), the primary way that genetic information can be exchanged by horizontal gene transfer between bacterial cells. MGEs facilitate horizontal genetic exchange, enabling S. aureus to become antibiotic resistant (Partridge et al., 2018). Through this, bacterial cells overcome antibiotics by obtaining pre-existing resistance factors from the bacterial gene pool of bacteria. Mobile genetic elements can move between or within DNA molecules via transposons, gene cassettes/integrons and insertion sequences. Some, such as integrative conjugative elements and plasmids, can be transferred between bacterial cells. S. aureus has MGEs that explain their ability to develop resistance to antibiotics over the years (Fig. 10.3).
Genetically Modified Salmonella as Cancer Therapeutics: Mechanisms, Advances, and Challenges
Published in Ananda M. Chakrabarty, Arsénio M. Fialho, Microbial Infections and Cancer Therapy, 2019
For bacterial delivery of cytotoxic compounds, genetic stability and a controllable high expression of heterologous genes are critical to ensure long-term release of therapeutic proteins. The heterologous genes can be either integrated into the bacterial chromosome or expressed on a plasmid. Replacement of specific sequences of chromosome with a therapeutic gene cassette allows the maximum genetic stability, as chromosomal DNA rarely undergoes mutation or deletion. Green fluorescent protein (GFP), cytosine deaminase (CDase) gene, and LIGHT have been successfully integrated into chromosome [12, 71, 72]. However, as only one copy of the heterologous gene is integrated into the chromosome, limited heterologous proteins are expressed and therapeutic outcomes are restricted.
Genetic Approaches for Modulating MRI Contrast
Published in Michel M. J. Modo, Jeff W. M. Bulte, Molecular and Cellular MR Imaging, 2007
Eric T. Ahrens, William F. Goins, Clinton S. Robison
Ideally, effective MRI gene reporter systems should be highly sensitive and have a rapid response time. The reporter gene “cassette” should be kept to a minimal nucleotide length for incorporation into vectors with insert size constraints. Furthermore, the gene products should be relatively nontoxic to cells even when expressed at high levels. From within the FT superfamily there are an immense number of different ferritin molecules that could be investigated for their efficacy as MRI gene reporters. These possibilities include FTs from various animals, plants, and bacteria. The nucleotide length (nt) of ferritin subunits is modest (~540 nt) compared to many common gene reporters (GFP, ~750 nt; LacZ, ~1020 nt).
Guidelines for the treatment of dysentery (shigellosis): a systematic review of the evidence
Published in Paediatrics and International Child Health, 2018
Phoebe C. M. Williams, James A. Berkley
Evidence suggests that antibiotic resistance is an increasing challenge in the therapeutic management of shigellosis, as recognised by the WHO prioritising ciprofloxacin-resistant shigella as a target of current international focus on antimicrobial resistance [52]. There are several mechanisms by which this may occur. In shigella spp., antimicrobial resistance is often owing to classes 1 and 2 integrons which contain resistance gene cassettes which are mobile and transferrable from one bacterium to another, providing a flexible way for bacteria to adapt to the environmental pressure caused by antibiotics. This may account for the dissemination of resistant genes and the emergence of multidrug-resistant strains, and explain why shigella resistance patterns vary worldwide – as the distribution of integrons varies according to the species and resistance phenotype (with. S. sonnei and S. boydii strains containing a single class 2 integron, while S. flexneri and S. dysenteriae carry a class 1 integron, often in combination with a class 2 integron which increases the propensity of dissemination of MDR strains of shigella) [53]. This underpins the importance of any antimicrobial resistance programme including surveillance to document changes in prevalent species in regions worldwide.
Design, selection and optimization of an anti-TRAIL-R2/anti-CD3 bispecific antibody able to educate T cells to recognize and destroy cancer cells
Published in mAbs, 2018
Alessandro Satta, Delia Mezzanzanica, Francesco Caroli, Barbara Frigerio, Massimo Di Nicola, Roland E. Kontermann, Federico Iacovelli, Alessandro Desideri, Andrea Anichini, Silvana Canevari, Alessandro Massimo Gianni, Mariangela Figini
A tascFv gene cassette (VHTRAIL-R2-flexible linker-VLTRAIL-R2-short linker-VHCD3-flexible linker-VLCD3 – see cartoon in Figure 1a-b) was designed and synthesized by GeneArt (Thermo Fisher Scientific). The cassette was originally designed containing clone 8 from the above library selection and the variable domains of the anti-CD3 TR66. The sequences of the variable domains of the TR66 mAb were obtained from the TR66 hybridoma provided by Prof. Lanzavecchia. For construction of the library we kept the anti-CD3 TR66 variable domains fixed and cloned as anti-TRAIL-R2 the pool of VH and VL that we selected after the second panning against the native protein, amplified by PCR, using a set of primers specific for all VH and Jk/Jλ germ lines.37
Characterization of integrons, extended-spectrum β-lactamases, AmpC cephalosporinase, quinolone resistance, and molecular typing of Shigella spp. from Iran
Published in Infectious Diseases, 2018
Sajjad Zamanlou, Mohammad Ahangarzadeh Rezaee, Mohammad Aghazadeh, Reza Ghotaslou, Farhad Babaie, Younes Khalili
PCR amplification of the internal variable region of the class 1 integron in 78 ESC-resistant isolates using CS-F/CS-R primers produced two different products of approximately 750 and 1600 bp in 2 (2.6%) and 19 (24.3%) isolates, respectively. Sequence analysis of the variable region indicated the presence of dfrA7 and dfrA17-aadA5 resistance gene cassettes among the isolates, which corresponded to 750 and 1600 bp PCR products, respectively. Furthermore, amplification of the internal variable region for the class 2 integron using hep74 and hep51 primers showed that 63 (80.8%) isolates harbored the class 2 integron. In addition, two types of gene cassettes were identified in class 2 integrons. Fifty-two (66.7%) strains had a 2300-bp fragment (with the sequence of dfrA1-sat1-aadA1), and 11 (14.1%) strains showed a 1500-bp fragment (with the sequence of dfrA1-sat1) (Figures in supplement data).