scholarly journals Targeted-Antibacterial-Plasmids (TAPs) combining conjugation and CRISPR/Cas systems achieve strain-specific antibacterial activity

2020 ◽  
Author(s):  
Audrey Reuter ◽  
Cécile Hilpert ◽  
Annick Dedieu-Berne ◽  
Sophie Lematre ◽  
Erwan Gueguen ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Carbapenem Resistance ◽  
Double Strand Breaks ◽  
Resistant Bacteria ◽  
Innovative Strategy ◽  
Strand Breaks ◽  
Drug Resistant Bacteria

AbstractThe global emergence of drug-resistant bacteria leads to the loss of efficacy of our antibiotics arsenal and severely limits the success of currently available treatments. Here, we developed an innovative strategy based on Targeted-Antibacterial-Plasmids (TAPs) that use bacterial conjugation to deliver CRISPR/Cas systems exerting a strain-specific antibacterial activity. TAPs are highly versatile as they can be directed against any specific genomic or plasmid DNA using the custom algorithm (CSTB) that identifies appropriate targeting spacer sequences. We demonstrate the ability of TAPs to induce strain-selective killing by introducing lethal double strand breaks (DSBs) into the targeted genomes. TAPs directed against a plasmid-born carbapenem resistance gene efficiently resensitise the strain to the drug. This work represents an essential step towards the development of an alternative to antibiotic treatments, which could be used for in situ microbiota modification to eradicate targeted resistant and/or pathogenic bacteria without affecting other non-targeted bacterial species.

scholarly journals Targeted-antibacterial-plasmids (TAPs) combining conjugation and CRISPR/Cas systems achieve strain-specific antibacterial activity

2021 ◽  
Vol 49 (6) ◽  
pp. 3584-3598
Author(s):  
Audrey Reuter ◽  
Cécile Hilpert ◽  
Annick Dedieu-Berne ◽  
Sophie Lematre ◽  
Erwan Gueguen ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Carbapenem Resistance ◽  
Double Strand Breaks ◽  
Resistant Bacteria ◽  
Innovative Strategy ◽  
Strand Breaks ◽  
Drug Resistant Bacteria

Abstract The global emergence of drug-resistant bacteria leads to the loss of efficacy of our antibiotics arsenal and severely limits the success of currently available treatments. Here, we developed an innovative strategy based on targeted-antibacterial-plasmids (TAPs) that use bacterial conjugation to deliver CRISPR/Cas systems exerting a strain-specific antibacterial activity. TAPs are highly versatile as they can be directed against any specific genomic or plasmid DNA using the custom algorithm (CSTB) that identifies appropriate targeting spacer sequences. We demonstrate the ability of TAPs to induce strain-selective killing by introducing lethal double strand breaks (DSBs) into the targeted genomes. TAPs directed against a plasmid-born carbapenem resistance gene efficiently resensitise the strain to the drug. This work represents an essential step toward the development of an alternative to antibiotic treatments, which could be used for in situ microbiota modification to eradicate targeted resistant and/or pathogenic bacteria without affecting other non-targeted bacterial species.

scholarly journals Comparative in vitro efficacy of eight essential oils as antibacterial agents against pathogenic bacteria isolated from pet-turtles

2018 ◽  
Vol 63 (No. 7) ◽  
pp. 335-343 ◽  
Author(s):  
BCJ De Silva ◽  
S. Hossain ◽  
SHMP Wimalasena ◽  
HNKS Pathirana ◽  
PS Dahanayake ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Essential Oils ◽  
Pathogenic Bacteria ◽  
Antibacterial Agents ◽  
Bacterial Species ◽  
Antimicrobial Properties ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Drug Resistant Bacteria

Essential oils are plant extracts that have been used for their antimicrobial properties for centuries. The keeping of turtles as pets exhibits a growing trend worldwide but these animals are known to harbour a range of pathogenic bacteria. In the current study, we assessed eight essential oils as alternative antibacterial agents against nine species of pet turtle-borne Gram-negative bacteria, namely Aeromonas caviae, A. dhakensis, A. hydrophila, Citrobacter freundii, Morganella morganii, Proteus mirabilis, P. vulgaris, Pseudomonas aeruginosa and Salmonella enterica. Except for Pseudomonas aeruginosa, all other bacterial species showed high susceptibility to six essential oils, namely oregano, cinnamon, clove, lemongrass, lavender and eucalyptus oils in descending order of efficacy. Minimum inhibitory concentrations and minimum bactericidal concentrations values of the essential oils against all tested species except for P. aeruginosa showed low heterogeneity, showing that these essential oils can effectively control the growth of nearly all the tested. However, most of the tested bacteria were multiple-antibiotic-resistant as determined in the antibiotic disc diffusion test, with multiple-antibiotic-resistant index values of ≥ 0.2 for most of the strains. Therefore, with regards to their in vitro activity in controlling growth of multi-drug resistant bacteria, we can classify oregano, cinnamon, clove, lemongrass, lavender and eucalyptus essential oils as effective antibacterial agents. Thus, prospective application of these essential oils in controlling and treating these bacteria should be considered.

A black phosphorus based synergistic antibacterial platform against drug resistant bacteria

2018 ◽  
Vol 6 (39) ◽  
pp. 6302-6310 ◽  
Author(s):  
Jiang Ouyang ◽  
Ren-Yu Liu ◽  
Wansong Chen ◽  
Zhenjun Liu ◽  
Qunfang Xu ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Ag Nanoparticles ◽  
Black Phosphorus ◽  
Growth Strategy ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Drug Resistant Bacteria ◽  
Synergistic Antibacterial Activity

Black phosphorus nanosheets were decorated with Ag nanoparticles through an in situ growth strategy, exhibiting synergistic antibacterial activity against drug-resistant bacteria.

scholarly journals Screening of in vitro Antibacterial Activity of Rumex vesicarius (L.) Leaves Extract against Twelve Pathogenic Bacterial

2020 ◽  
pp. 1-6
Author(s):  
Arnaba Saha Chaity ◽  
Md. Ashikul Islam ◽  
Tamanna Nasrin ◽  
Sathi Rani Sarker ◽  
Amit Kumar Dutta ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Xanthomonas Campestris ◽  
Pathogenic Bacteria ◽  
Methanol Extract ◽  
Bacterial Species ◽  
Resistant Bacteria ◽  
Zone Of Inhibition ◽  
Local Skin ◽  
In Vitro Antibacterial Activity

There is an alternative approaches from eradication of infections causes by pathogenic bacteria especially resistant bacteria. Methanol extract of Rumex vesicarius leaves were evaluated from in vitro antibacterial activity against twelve bacterial species were used which are four of them gram positive which are Streptococcus constellatus, Staphylococcus gallinarum, Staphylococcus sciuri and Streptococcus iniae and eight of them gram negative which are Aeromonas diversa, Xanthomonas campestris, Xanthomonas axonopodies, Siccibacter colletis, Edwardsielloa anguillarum, Aeromonas cavernicala, Enterobacter xiangfangenis and Vibro rotiferianus. The plant extract showed highest 12 mm zone of inhibition against Staphylococcus constellatus at the concentration of 20 μg/disc and no zone of inhibition was found from Aeromonas diversa. In minimum inhibitory concentration (MIC) test, methanol extract of Rumex vesicarious in 200μg/ml concentration showed best result against Vibrio rotiferianus. It can be concluded that methanol extracts of Rumex vesicarious leaves may be used as natural antibacterial from treatment of some diseases, especially local skin diseases.

scholarly journals Antibacterial Activity of Fluorobenzoylthiosemicarbazides and Their Cyclic Analogues with 1,2,4-Triazole Scaffold

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 170
Author(s):  
Urszula Kosikowska ◽  
Monika Wujec ◽  
Nazar Trotsko ◽  
Wojciech Płonka ◽  
Piotr Paneth ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Resistant Bacteria ◽  
Binding Affinities ◽  
Substitution Pattern ◽  
Minimal Inhibitory Concentrations ◽  
Gram Positive Bacteria ◽  
Structure Activity ◽  
Drug Resistant Bacteria ◽  
Reference Strains

The development of drug-resistant bacteria is currently one of the major challenges in medicine. Therefore, the discovery of novel lead structures for the design of antibacterial drugs is urgently needed. In this structure–activity relationship study, a library of ortho-, meta-, and para-fluorobenzoylthiosemicarbazides, and their cyclic analogues with 1,2,4-triazole scaffold, was created and tested for antibacterial activity against Gram-positive bacteria strains. While all tested 1,2,4-triazoles were devoid of potent activity, the antibacterial response of the thiosemicarbazides was highly dependent on substitution pattern at the N4 aryl position. The optimum activity for these compounds was found for trifluoromethyl derivatives such as 15a, 15b, and 16b, which were active against both the reference strains panel, and pathogenic methicillin-sensitive and methicillin-resistant Staphylococcus aureus clinical isolates at minimal inhibitory concentrations (MICs) ranging from 7.82 to 31.25 μg/mL. Based on the binding affinities obtained from docking, the conclusion can be reached that fluorobenzoylthiosemicarbazides can be considered as potential allosteric d-alanyl-d-alanine ligase inhibitors.

scholarly journals Development of an Immunochromatographic Strip Using Conjugated Gold Nanoparticles for the Rapid Detection of Klebsiella pneumoniae Causing Neonatal Sepsis

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1141
Author(s):  
Noha M. Elhosseiny ◽  
Tamer M. Samir ◽  
Aliaa A. Ali ◽  
Amani A. El-Kholy ◽  
Ahmed S. Attia
Keyword(s):  
Gold Nanoparticles ◽  
Klebsiella Pneumoniae ◽  
Causative Agent ◽  
Neonatal Sepsis ◽  
Bacterial Species ◽  
Resistant Bacteria ◽  
Immunochromatographic Strip ◽  
Amino Acid Peptide ◽  
Negative Results ◽  
Drug Resistant Bacteria

Neonatal sepsis is a leading cause of death among newborns and infants, especially in the developing world. The problem is compounded by the delays in pinpointing the causative agent of the infection. This is reflected in increasing mortality associated with these cases and the spread of multi-drug-resistant bacteria. In this work, we deployed bioinformatics and proteomics analyses to determine a promising target that could be used for the identification of a major neonatal sepsis causative agent, Klebsiella pneumoniae. A 19 amino acid peptide from a hypothetical outer membrane was found to be very specific to the species, well conserved among its strains, surface exposed, and expressed in conditions simulating infection. Antibodies against the selected peptide were conjugated to gold nanoparticles and incorporated into an immunochromatographic strip. The developed strip was able to detect as low as 105 CFU/mL of K. pneumoniae. Regarding specificity, it showed negative results with both Escherichia coli and Enterobacter cloacae. More importantly, in a pilot study using neonatal sepsis cases blood specimens, the developed strip selectively gave positive results within 20 min with those infected with K. pneumoniae without prior sample processing. However, it gave negative results in cases infected with other bacterial species.

scholarly journals Evolution of Chi motifs in Proteobacteria

2021 ◽  
Author(s):  
Angélique Buton ◽  
Louis-Marie Bobay
Keyword(s):  
Sequence Similarity ◽  
Bacterial Species ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Large Dataset ◽  
High Sequence Similarity ◽  
Strand Breaks ◽  
E Coli ◽  
Dna Motif ◽  
And Staphylococcus Aureus

Abstract Homologous recombination is a key pathway found in nearly all bacterial taxa. The recombination complex allows bacteria to repair DNA double strand breaks but also promotes adaption through the exchange of DNA between cells. In Proteobacteria, this process is mediated by the RecBCD complex, which relies on the recognition of a DNA motif named Chi to initiate recombination. The Chi motif has been characterized in Escherichia coli and analogous sequences have been found in several other species from diverse families, suggesting that this mode of action is widespread across bacteria. However, the sequences of Chi-like motifs are known for only five bacterial species: E. coli, Haemophilus influenzae, Bacillus subtilis, Lactococcus lactis and Staphylococcus aureus. In this study we detected putative Chi motifs in a large dataset of Proteobacteria and we identified four additional motifs sharing high sequence similarity and similar properties to the Chi motif of E. coli in 85 species of Proteobacteria. Most Chi motifs were detected in Enterobacteriaceae and this motif appears well conserved in this family. However, we did not detect Chi motifs for the majority of Proteobacteria, suggesting that different motifs are used in these species. Altogether these results substantially expand our knowledge on the evolution of Chi motifs and on the recombination process in bacteria.

scholarly journals Novel Seleno- and Thio-Urea Containing Dihydropyrrol-2-One Analogues as Antibacterial Agents

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 321
Author(s):  
Shekh Sabir ◽  
Tsz Tin Yu ◽  
Rajesh Kuppusamy ◽  
Basmah Almohaywi ◽  
George Iskander ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Antibiotic Resistance ◽  
Quorum Sensing ◽  
Antibacterial Agents ◽  
Inhibitory Concentration ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Positive Bacterium ◽  
Quorum Sensing Inhibition ◽  
Drug Resistant Bacteria

The quorum sensing (QS) system in multi-drug-resistant bacteria such as P. aeruginosa is primarily responsible for the development of antibiotic resistance and is considered an attractive target for antimicrobial drug discovery. In this study, we synthesised a series of novel selenourea and thiourea-containing dihydropyrrol-2-one (DHP) analogues as LasR antagonists. The selenium DHP derivatives displayed significantly better quorum-sensing inhibition (QSI) activities than the corresponding sulphur analogues. The most potent analogue 3e efficiently inhibited the las QS system by 81% at 125 µM and 53% at 31 µM. Additionally, all the compounds were screened for their minimum inhibitory concentration (MIC) against the Gram-positive bacterium S. aureus, and interestingly, only the selenium analogues showed antibacterial activity, with 3c and 3e being the most potent with a MIC of 15.6 µM.

scholarly journals Screening of active antimicrobial and biological enzymes of microbial isolated from soil in Thailand

2017 ◽  
Vol 10 (4) ◽  
pp. 73 ◽  
Author(s):  
Pannapa Powthong ◽  
Apichai Sripean ◽  
Pattra Suntornthiticharoen
Keyword(s):  
Pathogenic Bacteria ◽  
Soil Microorganisms ◽  
Extracellular Enzyme ◽  
Antimicrobial Activities ◽  
Lipase Production ◽  
Resistant Bacteria ◽  
Strong Activity ◽  
Preliminary Screening ◽  
Soil Microbial ◽  
Drug Resistant Bacteria

Objective: The objectives of this study were to isolate microorganisms and screen for potential antimicrobial activities from the soil. Methods: In this study, a total of 425 isolates were isolated from 100 soil samples. The preliminary screening for antimicrobial activities of these isolates was performed by modified cross-streak, agar diffusion, and modified icrodilution technique against 16 pathogenic bacteria and fungi.Results: In the anti-microbial activity, there were three isolates, namely, 277, 303, and 307 exhibited inhibitory activity against methicillin-resistantStaphylococcus aureus and Salmonella typhimurium respectively. This study also examined the various enzymes producing from soil microorganisms including chitinase, chitosanase, amylase, cellulose, caseinase, gelatinase, esterase, and lipase production of different selective media for 24 and 48hrs using the direct spot method. The results revealed that 28 isolates could produce various enzymes with strong activity. Most of them produced gelatinase (5.65%) and caseinase (5.18%). There were four isolates that produce broad-spectrum enzyme. In addition, the investigation of selectedmicroorganism identification showed that they can be divided into three groups: Burkholderia spp., Pseudomonas spp., and Rhodococcus spp.Conclusion: This study demonstrated that the microorganisms from soil are capable of producing potential, antibacterial, and bioactive enzymes.Keywords: Antimicrobial activity, Extracellular enzyme, Soil microbial, Drug-resistant bacteria.

scholarly journals Synergistic Antibacterial Activity of Lantana camara L., Parthenium hysterophorus L., Cannabis sativa L. and Justicia adhatoda L. Leaves Extract against Procured Multi-drug Resistant Bacteria In Vitro

2021 ◽  
pp. 34-40
Author(s):  
Jyoti Chandola ◽  
Pooja Singh ◽  
Rishabh Garg ◽  
Narotam Sharma
Keyword(s):  
Antibacterial Activity ◽  
Medicinal Plants ◽  
Cannabis Sativa ◽  
Lantana Camara ◽  
Parthenium Hysterophorus ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Drug Resistant Bacteria ◽  
Weed Plants ◽  
Justicia Adhatoda

The scientific study of this research has been focused on synergistic antibacterial activity of two weed plants, Lantana camara L., Parthenium hysterophorus L. alongwith two medicinal plants, Cannabis sativa L., Justicia adhatoda L. against multi- drug resistant (MDR) bacteria. Dried leaf powders of the plants were extracted using air-dried method followed by the ethanol- solvent extraction method for the crude extract of the leaves. The crude extracts were tested for antibacterial activity against three MDR bacteria, that is, one Gram positive bacteria- Staphylococcus aureus and two Gram negative bacteria- Escherichia coli and Proteus mirabilis. Out of 18 antibiotics tested against procured bacteria, Staphylococcus aureus was resistant to 10 out of 10 tested antibiotics, Escherichia coli was resistant to 4 out of 12 tested antibiotics and Proteus mirabilis was resistant to 9 out of 10 tested antibiotics. The tested weed plants and the medicinal plants when combined together showed more zone of inhibition against multidrug resistant bacteria ( Two combinations of phytochemicals Lantana camara, Cannabis sativa and Lantana camara, Cannabis sativa, Justicia adhatoda, Parthenium hysterophorus showed maximum zones of inhibition, that is, 30 mm) as compared to when these plants were tested solitarily, showing pronounced antibacterial activity. These findings showed that the antibacterial activity enhanced when they were combined together and this potential could be used against various infectious diseases with more research and modification in this area. Weed plants also holds as much importance as the medicinal plants although not to that extent, but they clearly inhibit the growth of bacteria and this property of weeds along with the medicinal plants holds a promising future in treating many diseases caused by multi-drug resistant bacteria on the pharmaceutical level.

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