Flow cytometry antibiotic

Broad spectrum activities, a unique mode of actions and rare resistant variants make antimicrobial peptide (AMP) a potential alternative to antibiotics. However, AMPs still have limitations in clinical development due to their physiological stability, toxicity and manufacturing costs. Cbf-14, derived from cathelicidin-BF has been proven to be effective against drug-resistant bacteria. Herein, a series of Cbf-14 mutants were designed to overcome these limitations. Design strategies included substitutions of lysine (Lys) or leucine (Leu) with similar residues such as ornithine (Orn) and norleucine (Ile), which are unnatural amino acids, to generate AMPs with enhanced therapeutic potential...

Objective To investigate the relationship between intestinal inflammation and the central and peripheral innate immune system, in the pathogenesis of HLA-B27 associated spondyloarthritis. Methods The myeloid compartment of the bone marrow and blood of HLA-B27 transgenic (B27), control HLA-B7 transgenic (B7), and non-transgenic rats were evaluated by flow cytometry. Plasma from rats were assessed by ELISA for CCL2 and IL-1α levels. Rats were treated for 4 weeks with antibiotics and the blood and bone marrow myeloid compartments were evaluated by flow cytometry...

The expanding global distribution of multi-resistant Klebsiella pneumoniae demands faster antimicrobial susceptibility testing (AST) to guide antibiotic treatment. Current ASTs rely on time-consuming differentiation of resistance and susceptibility after initial isolation of bacteria from a clinical specimen. Here we describe a flow cytometry workflow to determine carbapenem susceptibility from bacterial cell characteristics in an international K. pneumoniae isolate collection (n = 48), with a range of carbapenemases...

Salinomycin is a polyether ionophore antibiotic that has recently been shown to induce cell apoptosis in human cancer cells displaying multiple mechanisms of drug resistance. In the present study, we explored the impact of salinomycin on the apoptosis and autophagy as well as the correlation between those effects and endoplasmic reticulum (ER) stress molecular mechanisms in human glioma U87MG cells. Apoptosis, autophagy and reactive oxygen species (ROS) were analyzed using flow cytometry. In addition, expression levels of apoptosis-, autophagy- and ER stress-related proteins were determined by western blotting...

The TCR Vβ repertoire from patients with recurrent tonsillitis and/or tonsillar hyperplasia was examined to determine whether the TCR Vβ composition is suggestive of local superantigen activity and if so, whether it is associated with the presence of superantigen producing bacteria. Tonsil specimens were cultured aerobically to allow identification and isolation of the bacterial pathogens Staphylococcus aureus and Group A Streptococcus. TCR Vβ subset analysis of tonsil leucocytes was performed by flow cytometry...

The role of reactive oxygen species (ROS) in microbial metabolism and stress response has emerged as a major theme in microbiology and infectious disease. Reactive fluorescent dyes have the potential to advance the study of ROS in the complex intracellular environment, especially for high-content and high-throughput analyses. However, current dye-based approaches to measuring intracellular ROS have the potential for significant artifacts. Here, we describe a robust platform for flow cytometric quantification of ROS in bacteria using fluorescent dyes, with ROS measurements in 10s-of-1000s of individual cells under a variety of conditions...

BACKGROUND AND AIM: Antibiotics have many beneficial effects but their uncontrolled use may lead to increased risk of serious diseases in the future. Our hypothesis is that an early antibiotic exposition may affect immune system by altering gut microbiota. Therefore, the aim of the study was to determine the effect of penicillin treatment on gut microorganisms and immune system of mice. METHODS: 21-days old C57BL6/J/cmdb male mice were treated with low-dose of penicillin (study group) or water only (control group) for 4 weeks...

Activation of efflux systems and the formation of biofilm are majorly adapted by microbes to resist antimicrobial agents. PPEF (bisbenzimidazole) targeting topoisomerase IA is observed to be an effective bactericidal agent against both Gram-positive and Gram-negative bacterial strains and thus can be developed as potent broad-spectrum antibiotic against MDR strains. PPEF treatment did not cause target specific mutation instead it leads to up-regulation of efflux gene in E. coli K12 as a mechanism of resistance...

OBJECTIVES: This study investigated the phenotypic stability and biological properties of two human tongue cancer cell lines after transduction of fluorescent proteins. DESIGN: The human tongue cancer cell lines UM1 and UM2 were cultured with GFP and RFP lentiviral particles stock for 72h. Cells with successful transduction of fluorescent proteins were selected in a medium containing G418 antibiotics for two weeks. The proliferation rates of parental and transduced cell lines were evaluated by their population doubling time (PDT)...

Worm predation (WP) by Tubifex tubifex was investigated using waste activated sludge (WAS) as the substrate. In order to better understand the sludge degradation mechanisms during WP, the activity of five common hydrolytic enzymes was determined and compared among the initial feed activated sludge, endogenous respirated sludge and worm predated sludge. The results showed that the enzymatic activity decreased upon aerobic (worm) treatment of WAS and that this activity was predominantly associated with the removed solids fraction of the sludge...

BACKGROUND: For most physicians, quantification of drug-specific immunoglobulin E (drug-sIgE) antibodies constitutes the primary in vitro measure to document immediate drug hypersensitivity reactions (IDHR). Unfortunately, this is often insufficient to correctly identify patients with IgE-mediated IDHR and impossible for non-IgE-mediated IDHR that result from alternative routes of basophil and mast cell activation. In these difficult cases, diagnosis might benefit from cellular tests such as basophil activation tests (BAT)...

We reported defective efferocytosis associated with cigarette smoking and/or airway inflammation in chronic lung diseases, including chronic obstructive pulmonary disease, severe asthma, and childhood bronchiectasis. We also showed defects in phagocytosis of nontypeable Haemophilus influenzae (NTHi), a common colonizer of the lower airway in these diseases. These defects could be substantially overcome with low-dose azithromycin; however, chronic use may induce bacterial resistance. The aim of the present study was therefore to investigate two novel macrolides-2'-desoxy-9-(S)-erythromycylamine (GS-459755) and azithromycin-based 2'-desoxy molecule (GS-560660)-with significantly diminished antibiotic activity against Staphylococcus aureus, Streptococcus pneumonia, Moraxella catarrhalis, and H...

Antimicrobial peptides (AMPs) are potential alternatives to conventional antibiotics, as they have a fast mode of action, a low likelihood of resistance development and can act in conjunction with existing drug regimens. We report in this study the effects of batroxicidin (BatxC), a cathelicidin-related AMP from Bothrops atrox venom gland, over Trypanosoma cruzi, a protozoan that causes Chagas' disease. BatxC inhibited all T. cruzi (Y strain: benznidazole-resistant) developmental forms, with selectivity index of 315...

The use of lactic acid bacteria (LAB) as bioprotective cultures can be an alternative to chemical preservatives or antibiotic to prevent fungal spoilage in dairy products. Among antifungal LAB, Lactobacillus harbinensis K.V9.3.1Np showed a remarkable antifungal activity for the bioprotection of fermented milk without modifying their organoleptic properties (Delavenne et al., 2015). The aim of the present study was to elucidate the action mechanism of this bioprotective strain against the spoilage yeast Yarrowia lipolytica...

Pathogenic bacteria are able to develop resistance mechanisms to avoid the antimicrobial potential of antibiotics becoming an increasing problem for the healthcare systems. The search for more effective and selective antimicrobial materials, though not harmful to mammalian cells, seems imperative. Herein we propose the use of gold-chitosan nanocomposites as effective bactericidal materials avoiding the damage to human cells. Nanocomposites were obtained taking advantage of the reductive and stabilizing action of chitosan solutions on two different gold precursor concentrations...

Use of antibiotic-contaminated manure in crop production poses a severe threat to soil and plant health. However, few studies have studied the mechanism by which plant development is affected by antibiotics. Here, we used microscopy, flow cytometry, gene expression analysis and fluorescent dyes to study the effects of oxytetracycline (OTC), a widely used antibiotic in agriculture, on root meristem activity and the accumulation of hydrogen peroxide (H2O2) and nitric oxide (NO) in the root tips of tomato seedlings...

The changes induced in bacterial strains under stress conditions provide an insight into metal resistance strategies. Trivalent chromium resistant bacterium were isolated and identified by 16S rRNA gene sequencing and designated as Alcaligenes faecalis VITSIM2. The growth pattern was monitored. The organism also showed resistance to copper, cadmium, and certain antibiotics. The differentially expressed proteins in SDS PAGE were identified by mass spectrometry as flagellin and 50S ribosomal L36 protein. The morphological changes were identified by scanning electron microscopy...

Macrophages are natural host cells for pathogenic mycobacteria, like Mycobacterium tuberculosis (M.tb). Immune surveillance by T cells and interaction with M.tb infected macrophages is crucial for protection against M.tb reactivation and development of active tuberculosis. Several factors play a role in the control of M.tb infection but reliable biomarkers remain elusive. One major obstacle is the absence of functional in vitro assays which allow concomitant determination of i) mycobacterial eradication; ii) cytotoxic effects on host macrophages; and iii) effector T-cell functions...

OBJECTIVE: To determine whether intestinal colonization with methicillin-resistant Staphylococcus aureus (MRSA) can be the source of surgical site infections (SSIs). BACKGROUND: We hypothesized that gut-derived MRSA may cause SSIs via mechanisms in which circulating immune cells scavenge MRSA from the gut, home to surgical wounds, and cause infection (Trojan Horse Hypothesis). METHODS: MRSA gut colonization was achieved by disrupting the microbiota with antibiotics, imposing a period of starvation and introducing MRSA via gavage...

BACKGROUND: Medical advances in the field of infection therapy has led to an increasing use of antibiotics, which, apart from eliminating pathogens, also partially eliminate naturally existing commensal bacteria. It has become increasingly clear that less exposure to microbiota early in life may contribute to the observed rise in "immune-mediated" diseases including autoimmunity and allergy. OBJECTIVE: We sought to test whether the change of gut microbiota with the broad spectrum antibiotic enrofloxacin will modulate contact sensitivity (CS) in mice...