Molecular Mechanisms of Antibiotic Resistance in Gram-Positive Pathogens.

2001 ◽  
Vol 1 (1) ◽  
pp. 63-77 ◽  
Author(s):  
A. Dessen ◽  
A. Di Guilmi ◽  
T. Vernet ◽  
O. Dideberg
Keyword(s):  
Antibiotic Resistance ◽  
Molecular Mechanisms ◽  
Gram Positive

scholarly journals Anti-staphylococcal activity and mode of action of thioridazine photoproducts

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tatiana Tozar ◽  
Sofia Santos Costa ◽  
Ana-Maria Udrea ◽  
Viorel Nastasa ◽  
Isabel Couto ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Molecular Docking ◽  
Infectious Diseases ◽  
Molecular Mechanisms ◽  
Dynamic Surface Tension ◽  
Docking Studies ◽  
Gram Positive ◽  
Dynamic Surface ◽  
Gram Positive Bacteria

Abstract Antibiotic resistance became an increasing risk for population health threatening our ability to fight infectious diseases. The objective of this study was to evaluate the activity of laser irradiated thioridazine (TZ) against clinically-relevant bacteria in view to fight antibiotic resistance. TZ in ultrapure water solutions was irradiated (1–240 min) with 266 nm pulsed laser radiation. Irradiated solutions were characterized by UV–Vis and FTIR absorption spectroscopy, thin layer chromatography, laser-induced fluorescence, and dynamic surface tension measurements. Molecular docking studies were made to evaluate the molecular mechanisms of photoproducts action against Staphylococcus aureus and MRSA. More general, solutions were evaluated for their antimicrobial and efflux inhibitory activity against a panel of bacteria of clinical relevance. We observed an enhanced antimicrobial activity of TZ photoproducts against Gram-positive bacteria. This was higher than ciprofloxacin effects for methicillin- and ciprofloxacin-resistant Staphylococcus aureus. Molecular docking showed the Penicillin-binding proteins PBP3 and PBP2a inhibition by sulforidazine as a possible mechanism of action against Staphylococcus aureus and MRSA strains, respectively. Irradiated TZ reveals possible advantages in the treatment of infectious diseases produced by antibiotic-resistant Gram-positive bacteria. TZ repurposing and its photoproducts, obtained by laser irradiation, show accelerated and low-costs of development if compared to chemical synthesis.

scholarly journals Next Generation Sequencing for the Prediction of the Antibiotic Resistance in Helicobacter pylori: A Literature Review

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 437
Author(s):  
Ilaria Maria Saracino ◽  
Matteo Pavoni ◽  
Angelo Zullo ◽  
Giulia Fiorini ◽  
Tiziana Lazzarotto ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Next Generation Sequencing ◽  
Literature Review ◽  
Molecular Mechanisms ◽  
World Health ◽  
Next Generation ◽  
Culture Methods ◽  
Phenotypic Resistance ◽  
H Pylori ◽  
Generation Sequencing

Background and aims: Only a few antimicrobials are effective against H. pylori, and antibiotic resistance is an increasing problem for eradication therapies. In 2017, the World Health Organization categorized clarithromycin resistant H. pylori as a “high-priority” bacterium. Standard antimicrobial susceptibility testing can be used to prescribe appropriate therapies but is currently recommended only after the second therapeutic failure. H. pylori is, in fact, a “fastidious” microorganism; culture methods are time-consuming and technically challenging. The advent of molecular biology techniques has enabled the identification of molecular mechanisms underlying the observed phenotypic resistance to antibiotics in H. pylori. The aim of this literature review is to summarize the results of original articles published in the last ten years, regarding the use of Next Generation Sequencing, in particular of the whole genome, to predict the antibiotic resistance in H. pylori.Methods: a literature research was made on PubMed. The research was focused on II and III generation sequencing of the whole H. pylori genome. Results: Next Generation Sequencing enabled the detection of novel, rare and complex resistance mechanisms. The prediction of resistance to clarithromycin, levofloxacin and amoxicillin is accurate; for other antimicrobials, such as metronidazole, rifabutin and tetracycline, potential genetic determinants of the resistant status need further investigation.

Gram-positive bacteria secrete RNA aptamers to activate human STING for IL-1β release.

2021 ◽  
Author(s):  
Shivalee N Duduskar ◽  
Mohamed Ghait ◽  
Martin Westermann ◽  
Huijuan Guo ◽  
Anuradha Ramoji ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Rna Aptamers ◽  
Inflammasome Activation ◽  
Accessory Gene ◽  
Group B Streptococci ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Accessory Gene Regulator ◽  
New Perspective ◽  
Group B

Molecular mechanisms through which Gram-positive bacteria induce the canonical inflammasome are poorly understood. Here, we studied the effects of Group B streptococci (GBS) and Staphylococcus aureus (SA) on inflammasome activation in human macrophages. Dinucleotide binding small RNA aptamers released by SA and GBS were shown to trigger increased IL-1β generation by inflammasomes. The stimulator of interferon genes-STING as a central mediator of innate immune responses has been identified as the key target of pathogenic RNA. Multi-lamellar lipid bodies (MLBs) produced by SA function as vehicles for the RNA aptamers. Notably, expression of RNA aptamers is controlled by an accessory gene regulator quorum sensing system of the bacteria. These findings have been translated to patients with Gram-positive sepsis showing hallmarks of MLB-RNA-mediated inflammasome activation. Together our findings may provide a new perspective for the pathogenicity of Gram-positive bacterial infection in man.

scholarly journals Antibiotic Resistance and Biofilm Production in Catalase-Positive Gram-Positive Cocci Isolated from Brazilian Pasteurized Milk

2020 ◽  
Author(s):  
M.A.A. Machado ◽  
W.A. Ribeiro ◽  
V.S. Toledo ◽  
G.L.P.A. Ramos ◽  
H.C. Vigoder ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Qualitative Evaluation ◽  
Multidrug Resistant ◽  
Gram Positive ◽  
Antibiotic Resistant ◽  
Pasteurized Milk ◽  
Biofilm Production ◽  
Diffusion Technique ◽  
Gram Positive Cocci

Background: Milk is a reservoir for several groups of microorganisms, which may pose health risks. The aim of this work was to assess the antibiotic resistance and biofilm production in catalase-positive Gram-positive cocci isolated from Brazilian pasteurized milk. Methods: The bacteria were isolated using Baird-Parker agar and identified by MatrixAssisted Laser Desorption/Ionization-Time-Of-Flight (MALDI-TOF) mass spectrometer. Disk diffusion technique was used to evaluate antimicrobial susceptibility. For qualitative evaluation of biofilm production, the growth technique was used on Congo Red Agar. Results: Totally, 33 out of 64 isolates were identified, including Staphylococcus epidermidis (n=3; 4.7%), Macrococcus caseolyticus (n=14; 21.9%), and Kocuria varians (n=16; 25%). Twenty-two isolates were resistant to at least one antibiotic. Biofilm production was detected in only 5 isolates of K. varians and 1 isolate of S. epidermidis. All 14 M. caseolyticus isolates were resistant to at least one antibiotic; but, multidrug resistant (MDR) isolates were not detected. Among all K. varians isolates, 4 were resistant to at least one antibiotic from three different classes and were considered to be MDR. Conclusion: The presence of antibiotic-resistant M. caseolyticus, S. epidermidis, and K. varians isolates, especially MDRs, in milk samples highlights the possible role of milk as a reservoir of resistance genes

scholarly journals Antibiotic resistance in lactococci and enterococci: phenotypic and molecular-genetic aspects

2017 ◽  
Vol 1 (1) ◽  
pp. 10-17
Author(s):  
Danuta Plotnikava ◽  
Anastasiya Sidarenka ◽  
Galina Novik
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Antibiotic Resistance Genes ◽  
Public Health Problem ◽  
Animal Husbandry ◽  
Resistant Bacteria ◽  
Monitoring And Control ◽  
Bacterial Drug Resistance

Abstract Extensive use of antibiotics in medicine, veterinary practice and animal husbandry has promoted the development and dissemination of bacterial drug resistance. The number of resistant pathogens causing common infectious diseases increases rapidly and creates worldwide public health problem. Commensal bacteria, including lactic acid bacteria of genera Enterococcus and Lactococcus colonizing gastrointestinal and urogenital tracts of humans and animals may act as vehicles of antibiotic resistance genes similar to those found in pathogens. Lactococci and enterococci are widely used in manufacturing of fermented products and as probiotics, therefore monitoring and control of transmissible antibiotic resistance determinants in industrial strains of these microorganisms is necessary to approve their Qualified Presumption of Safety status. Understanding the nature and molecular mechanisms of antibiotic resistance in enterococci and lactococci is essential, as intrinsic resistant bacteria pose no threat to environment and human health in contrast to bacteria with resistance acquired through horizontal transfer of resistance genes. The review summarizes current knowledge concerning intrinsic and acquired antibiotic resistance in Lactococcus and Enterococcus genera, and discusses role of enterococci and lactococci in distribution of this feature.

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