piperidines and Staphylococcal-Infections

Topics: Adenine; Agammaglobulinaemia Tyrosine Kinase; Aged; Blister; Hemorrhage; Humans; Leukemia, Lymphocytic, Chronic, B-Cell; Male; Piperidines; Protein Kinase Inhibitors; Purpura; Skin; Staphylococcal Infections; Staphylococcus aureus

Novel antibacterial agents needed constantly to counter the ever emergent resistance development to commercially available drugs; one of the effective synthetic antibacterial classes is fluoroquinolone (FQ). This study includes structure activity relationship based design and synthesis of novel fluoroquinolone molecules active against resistant pathogens bearing mutations of DNA gyrase and/or topoisomerase IV which also express efflux pumps. Here, series of compounds were prepared by treating 1-cyclopropyl-6,7-difluoro-8-methoxy-1,4-dihydro-4-oxo-quinoline-3-carboxylic acid as a core with various 4-substituted-3,3-dialkyl piperidines as side chains, through conventional synthetic approaches. Subsequently, antibacterial activities of these fluoroquinolones were examined against Streptococcus pneumoniae, SPN 5844 (Moxi resistant DNA gyrase and topo IV mutant) and SPN 706 (FQ efflux positive). The current manuscript covers >50 examples of fluoroquinolone NCEs, amongst 20 NCEs have shown MIC in the range of (0.4 to >6.25 μg/ml) for SPN 5844 and (0.1-12.5 μg/ml) for SPN 706 strains. During the course of this study; WCK 919, comprising two chiral isomers; WCK 1152 and WCK 1153 were emerged as lead among the different series synthesized. Advance studies suggested either WCK 1152 or WCK 1153 are the worthy candidates for further clinical developments for respiratory infections caused by resistant pneumococci and staphylococci. However, on the basis of in house preclinical work, WCK 1152 had been selected for phase-1 domestic clinical trials.

Topics: Anti-Bacterial Agents; DNA Gyrase; DNA Topoisomerase IV; Fluoroquinolones; Humans; Microbial Sensitivity Tests; Piperidines; Respiratory Tract Infections; Staphylococcal Infections; Staphylococcus; Streptococcus pneumoniae; Structure-Activity Relationship

Staphylococcus aureus is the leading cause of infections worldwide, and methicillin-resistant strains (MRSA) are emerging. New strategies are urgently needed to overcome this threat. Using a cell-based screen of ~45,000 diverse synthetic compounds, we discovered a potent bioactive, MAC-545496, that reverses β-lactam resistance in the community-acquired MRSA USA300 strain. MAC-545496 could also serve as an antivirulence agent alone; it attenuates MRSA virulence in Galleria mellonella larvae. MAC-545496 inhibits biofilm formation and abrogates intracellular survival in macrophages. Mechanistic characterization revealed MAC-545496 to be a nanomolar inhibitor of GraR, a regulator that responds to cell-envelope stress and is an important virulence factor and determinant of antibiotic resistance. The small molecule discovered herein is an inhibitor of GraR function. MAC-545496 has value as a research tool to probe the GraXRS regulatory system and as an antibacterial lead series of a mechanism to combat drug-resistant Staphylococcal infections.

Topics: Animals; Anti-Bacterial Agents; beta-Lactam Resistance; Biofilms; High-Throughput Screening Assays; Larva; Lepidoptera; Methicillin-Resistant Staphylococcus aureus; Mice; Microbial Sensitivity Tests; Piperidines; Pyridines; RAW 264.7 Cells; Staphylococcal Infections; Virulence Factors

Tofacitinib, a janus kinase inhibitor, is a novel immunosuppressive drug for treatment of rheumatoid arthritis (RA). Septic arthritis (SA) and sepsis caused by Staphylococcus aureus (S. aureus), for which RA patients are at risk, are infections with high mortality. The aim of this study was to investigate the effect of tofacitinib on S. aureus infections using mouse models. In vitro tofacitinib treated mouse splenocytes were stimulated with S. aureus derived stimuli. Mice pre-treated with tofacitinib were inoculated intravenously with either arthritogenic- or septic doses of S. aureus. Arthritis severity and mortality were compared between groups. Additionally, pre-treated mice were challenged with staphylococcal toxin TSST-1 to induce shock. Tofacitinib inhibited splenocyte proliferation and IFN-γ production in response to TSST-1 and dead S. aureus. In SA, tofacitinib treatment aggravated arthritis with more severe bone erosions. However, in sepsis, treated mice displayed significantly prolonged survival compared to controls. Similarly, in staphylococcal enterotoxin-induced shock tofacitinib pre-treatment, but not late treatment dramatically reduced mortality, which was accompanied by decreased levels of TNF-α and IFN-γ. Our findings show that tofacitinib treatment increase susceptibility of SA in mice, but has a positive effect on survival in S. aureus-induced sepsis and a strong protective effect in toxin-induced shock.

Topics: Animals; Arthritis, Infectious; Cytokines; Disease Progression; Drug Administration Schedule; Female; Immunosuppressive Agents; Janus Kinases; Mice; Mice, Inbred BALB C; Piperidines; Protein Kinase Inhibitors; Pyrimidines; Sepsis; Shock, Septic; Spleen; Staphylococcal Infections; Staphylococcus aureus; T-Lymphocytes

Staphylococcus aureus is often found in orthopaedic infections and may be protected from commonly prescribed antibiotics by forming biofilms or growing intracellularly within osteoblasts. To investigate the effect of non-antibiotic compounds in conjunction with antibiotics to clear intracellular and biofilm forming S. aureus causing osteomyelitis. SAOS-2 osteoblast-like cell lines were infected with S. aureus BB1279. Antibiotics (vancomycin, VAN; and dicloxacillin, DICLOX), bacterial efflux pump inhibitors (piperine, PIP; carbonyl cyanide m-chlorophenyl hydrazone, CCCP), and bone morphogenetic protein (BMP-2) were evaluated individually and in combination to kill intracellular bacteria. We present direct evidence that after gentamicin killed extracellular planktonic bacteria and antibiotics had been stopped, seeding from the infected osteoblasts grew as biofilms. VAN was ineffective in treating the intracellular bacteria even at 10× MIC; however in presence of PIP or CCCP the intracellular S. aureus was significantly reduced. Bacterial efflux pump inhibitors (PIP and CCCP) were effective in enhancing permeability of antibiotics within the osteoblasts and facilitated killing of intracellular S. aureus. Confocal laser scanning microscopy (CLSM) showed increased uptake of propidium iodide within osteoblasts in presence of PIP and CCCP. BMP-2 had no effect on growth of S. aureus either alone or in combination with antibiotics. Combined application of antibiotics and natural agents could help in the treatment of osteoblast infected intracellular bacteria and biofilms associated with osteomyelitis. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1086-1092, 2018.

Topics: Alkaloids; Anti-Bacterial Agents; Benzodioxoles; Bone Morphogenetic Protein 2; Carbonyl Cyanide m-Chlorophenyl Hydrazone; Cell Line, Tumor; Dicloxacillin; Drug Evaluation, Preclinical; Drug Synergism; Drug Therapy, Combination; Host-Pathogen Interactions; Humans; Microbial Sensitivity Tests; Osteoblasts; Osteomyelitis; Piperidines; Polyunsaturated Alkamides; Staphylococcal Infections; Staphylococcus aureus; Vancomycin

Immune cells utilize acetylcholine as a paracrine-signaling molecule. Many white blood cells express components of the cholinergic signaling pathway, and these are up-regulated when immune cells are activated. However, in vivo molecular imaging of cholinergic signaling in the context of inflammation has not previously been investigated.. We performed positron emission tomography (PET) using the glucose analogue 18F-FDG, and 11C-donepezil and 18F-FEOBV, markers of acetylcholinesterase and the vesicular acetylcholine transporter, respectively. Mice were inoculated subcutaneously with Staphylococcus aureus, and PET scanned at 24, 72, 120, and 144 h post-inoculation. Four pigs with post-operative abscesses were also imaged. Finally, we present initial data from human patients with infections, inflammation, and renal and lung cancer.. In mice, the FDG uptake in abscesses peaked at 24 h and remained stable. The 11C-donepezil and 18F-FEOBV uptake displayed progressive increase, and at 120-144 h was nearly at the FDG level. Moderate 11C-donepezil and slightly lower 18F-FEOBV uptake were seen in pig abscesses. PCR analyses suggested that the 11C-donepezil signal in inflammatory cells is derived from both acetylcholinesterase and sigma-1 receptors. In humans, very high 11C-donepezil uptake was seen in a lobar pneumonia and in peri-tumoral inflammation surrounding a non-small cell lung carcinoma, markedly superseding the 18F-FDG uptake in the inflammation. In a renal clear cell carcinoma no 11C-donepezil uptake was seen.. The time course of cholinergic tracer accumulation in murine abscesses was considerably different from 18F-FDG, demonstrating in the 11C-donepezil and 18F-FEOBV image distinct aspects of immune modulation. Preliminary data in humans strongly suggest that 11C-donepezil can exhibit more intense accumulation than 18F-FDG at sites of chronic inflammation. Cholinergic PET imaging may therefore have potential applications for basic research into cholinergic mechanisms of immune modulation, but also clinical applications for diagnosing infections, inflammatory disorders, and cancer inflammation.

Topics: Acetylcholinesterase; Adult; Aged; Animals; Carbon Radioisotopes; Carcinoma, Non-Small-Cell Lung; Carcinoma, Renal Cell; Cholinesterase Inhibitors; Donepezil; Female; Fluorodeoxyglucose F18; Humans; Indans; Kidney Neoplasms; Lung Neoplasms; Magnetic Resonance Imaging; Male; Mice; Mice, Inbred C57BL; Middle Aged; Piperidines; Positron Emission Tomography Computed Tomography; Radiopharmaceuticals; Staphylococcal Infections; Swine; Vesicular Acetylcholine Transport Proteins

We report four patients developing a late form of papulopustular rash induced by epidermal growth factor receptor inhibitors. These patients presented an unusual presentation of acneiform rash, characterized by late development (several months after treatment commenced), localization to the limbs with sparing of the face, and association with severe pruritus and Staphylococcus aureus superinfection in all cases. These clinical symptoms may suggest a distinct mechanism from the early acne-like rash frequently observed with these targeted anticancer therapies. Clinicians should be aware of this delayed adverse event, and we suggest the term 'late acneiform toxicity of EGFR inhibitors (LATE) syndrome' to permit better characterization of this clinical picture.

Topics: Adult; Aged; ErbB Receptors; Erlotinib Hydrochloride; Female; Humans; Male; Middle Aged; Piperidines; Protein Kinase Inhibitors; Pruritus; Quinazolines; Skin Diseases, Papulosquamous; Staphylococcal Infections; Staphylococcus aureus

The host innate immune response is the first line of defense against pathogens and is orchestrated by the concerted expression of genes induced by microbial stimuli. Deregulated expression of these genes is linked to the initiation and progression of diseases associated with exacerbated inflammation. We identified topoisomerase 1 (Top1) as a positive regulator of RNA polymerase II transcriptional activity at pathogen-induced genes. Depletion or chemical inhibition of Top1 suppresses the host response against influenza and Ebola viruses as well as bacterial products. Therapeutic pharmacological inhibition of Top1 protected mice from death in experimental models of lethal inflammation. Our results indicate that Top1 inhibition could be used as therapy against life-threatening infections characterized by an acutely exacerbated immune response.

Topics: Animals; Azepines; Camptothecin; DNA Topoisomerases, Type I; Ebolavirus; Flavonoids; Gene Expression Regulation; HEK293 Cells; Hemorrhagic Fever, Ebola; Host-Pathogen Interactions; Humans; Immunity, Innate; Inflammation; Influenza A virus; Interferon-beta; Mice; Mice, Inbred C57BL; Piperidines; Positive Transcriptional Elongation Factor B; RNA Polymerase II; Sendai virus; Staphylococcal Infections; Staphylococcus aureus; Topoisomerase I Inhibitors; Topotecan; Transcription, Genetic; Triazoles

Thymidylate kinase (TMK), an essential enzyme in bacterial DNA biosynthesis, is an attractive therapeutic target for the development of novel antibacterial agents, and we continue to explore TMK inhibitors with improved potency, protein binding, and pharmacokinetic potential. A structure-guided design approach was employed to exploit a previously unexplored region in Staphylococcus aureus TMK via novel interactions. These efforts produced compound 39, with 3 nM IC50 against S. aureus TMK and 2 μg/mL MIC against methicillin-resistant S. aureus (MRSA). This compound exhibits a striking inverted chiral preference for binding relative to earlier compounds and also has improved physical properties and pharmacokinetics over previously published compounds. An example of this new series was efficacious in a murine S. aureus infection model, suggesting that compounds like 39 are options for further work toward a new Gram-positive antibiotic by maintaining a balance of microbiological potency, low clearance, and low protein binding that can result in lower efficacious doses.

Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; Binding Sites; Crystallography, X-Ray; Drug Resistance, Bacterial; Gram-Positive Bacteria; Hydrophobic and Hydrophilic Interactions; Mice; Microbial Sensitivity Tests; Models, Molecular; Nucleoside-Phosphate Kinase; Piperidines; Protein Conformation; Pyrimidinones; Staphylococcal Infections; Staphylococcus aureus; Stereoisomerism; Structure-Activity Relationship

Medicinal plants represent an important opportunity to rural communities in Africa, as a source of affordable medicine and as a source of income. Increased patient awareness about safe usage is important as well as more training with regards to traditional medicine. The aim of this study was to evaluate the ethnomedicinal prowess of some indigenous South African plants commonly used in Eastern Cape Province of South Africa for the treatment of skin and respiratory tract infections, HIV and their toxicity potential.. Cassine transvaalensis, Vangueria infausta, Croton gratissimus and Vitex ferruginea were tested for antibacterial activities against Staphylococcus aureus and Staphylococcus epidermidis using Kirby-Bauer disk diffusion and minimum inhibition concentration (MIC). Cytotoxic and anti-HIV-1 activities of plants were tested using MTT Assay (3- (Dimethylthiozole-2-yl-2,5-diphenyltetrazolium bromide)) and anti- HIV-1iib assay. In search of bioactive lead compounds, Cassine transvaalensis which was found to be the most active plant extract against the two Staphylocoous bacteria was subjected to various chromatographic. Thin layer chromatography, Column chromatography and Nuclear Magnetic Resonance (NMR), (1H-1H, 13C-13C, in DMSO_d6, Bruker 600 MHz) were used to isolate and characterize 3-Oxo-28-hydroxylbetuli-20(29)-ene and 3,28-dihydroxylbetuli-20(29)-ene bioactive compounds from C. transvaalensis.. The four plants studied exhibited bioactive properties against the test isolates. The zones of inhibition ranged between 16 mm to 31 mm for multi-drug resistant staphylococci species. MIC values varied between 0.6 and 0.02 μg/ml. C. gratissimus and C. transvaalensis exhibited the abilities to inhibit HIV-1iib. Two bioactive compounds were isolated from C. transvaalensis.. Data from this study reveals the use of these plant by traditional healers in the Eastern Cape. Furthermore, C. transvaalensis and C. gratissimus were found to be more active as against HIV-1iib. While C. transvaalensis was most active against the two Staphylococcus bacteria.

Topics: Anti-Bacterial Agents; Anti-HIV Agents; Celastraceae; Chromatography, Thin Layer; Croton; HIV Infections; HIV-1; Humans; Ketones; Medicine, African Traditional; Microbial Sensitivity Tests; Piperidines; Plant Extracts; Plants, Medicinal; Rubiaceae; South Africa; Staphylococcal Infections; Staphylococcus; Vitex; Wound Healing

Novel non-fluoroquinolone inhibitors of bacterial type II topoisomerases (DNA gyrase and topoisomerase IV) are of interest for the development of new antibacterial agents that are not impacted by target-mediated cross-resistance with fluoroquinolones. N-Linked amino piperidines, such as 7a, generally show potent antibacterial activity, including against quinolone-resistant isolates, but suffer from hERG inhibition (IC(50) = 44 μM for 7a) and QT prolongation in vivo. We now disclose the finding that new analogues of 7a with reduced pK(a) due to substitution with an electron-withdrawing substituent in the piperidine moiety, such as R,S-7c, retained the Gram-positive activity of 7a but showed significantly less hERG inhibition (IC(50) = 233 μM for R,S-7c). This compound exhibited moderate clearance in dog, promising efficacy against a MRSA strain in a mouse infection model, and an improved in vivo QT profile as measured in a guinea pig in vivo model. As a result of its promising activity, R,S-7c was advanced into phase I clinical studies.

Topics: Administration, Oral; Animals; Anti-Bacterial Agents; Biological Availability; Dioxanes; DNA Topoisomerase IV; Dogs; Drug Resistance, Bacterial; ERG1 Potassium Channel; Ether-A-Go-Go Potassium Channels; Guinea Pigs; Methicillin-Resistant Staphylococcus aureus; Mice; Microbial Sensitivity Tests; Piperidines; Quinolones; Staphylococcal Infections; Stereoisomerism; Structure-Activity Relationship; Topoisomerase II Inhibitors

Piperine, a trans-trans-isomer of 1-piperoyl-piperidine, was tested in combination with mupirocin for antimicrobial activity against Staphylococcus aureus strains including meticillin-resistant S. aureus. The combination markedly reduced the MIC of mupirocin and also lowered the mutation frequency. Enhanced accumulation and efflux of ethidium bromide from wild-type and mutant (Mup(r)-1) strains in the presence of piperine indicated that inhibition of efflux could be a possible mechanism of potentiation of mupirocin activity by piperine. The combination of piperine with mupirocin in a dermal infection model of mice showed better in vivo efficacy when compared with the commercially available formulation of 2 % mupirocin.

Topics: Alkaloids; Animals; Anti-Bacterial Agents; Bacterial Proteins; Benzodioxoles; Disease Models, Animal; Drug Synergism; Enzyme Inhibitors; Ethidium; Female; Membrane Transport Proteins; Methicillin-Resistant Staphylococcus aureus; Mice; Microbial Sensitivity Tests; Mupirocin; Piperidines; Polyunsaturated Alkamides; Rodent Diseases; Staphylococcal Infections; Treatment Outcome

Novel non-fluoroquinolone inhibitors of bacterial type II topoisomerases (DNA gyrase and topoisomerase IV) are of interest for the development of new antibacterial agents that are not impacted by target-mediated cross-resistance with fluoroquinolones. Aminopiperidines that have a bicyclic aromatic moiety linked through a carbon to an ethyl bridge, such as 1, generally show potent broad-spectrum antibacterial activity, including quinolone-resistant isolates, but suffer from potent hERG inhibition (IC(50)= 3 μM for 1). We now disclose the finding that new analogues of 1 with an N-linked cyclic amide moiety attached to the ethyl bridge, such as 24m, retain the broad-spectrum antibacterial activity of 1 but show significantly less hERG inhibition (IC(50)= 31 μM for 24m) and higher free fraction than 1. One optimized analogue, compound 24l, showed moderate clearance in the dog and promising efficacy against Staphylococcus aureus in a mouse thigh infection model.

Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; DNA Topoisomerases, Type II; Dogs; Drug Resistance, Bacterial; ERG1 Potassium Channel; Ether-A-Go-Go Potassium Channels; Gram-Negative Bacteria; Gram-Positive Bacteria; Mice; Microbial Sensitivity Tests; Models, Molecular; Piperidines; Protein Conformation; Rats; Staphylococcal Infections; Structure-Activity Relationship; Topoisomerase Inhibitors

The pathophysiology of sepsis is due in part to early systemic inflammation. Here we describe molecular and cellular responses, as well as survival, in A 2A adenosine receptor (AR) agonist treated and untreated animals during experimental sepsis.. Sepsis was induced in mice by intraperitoneal inoculation of live bacteria (Escherichia coli or Staphylococcus aureus) or lipopolysaccharide (LPS). Mice inoculated with live bacteria were treated with an A 2A AR agonist (ATL313) or phosphate buffered saline (PBS), with or without the addition of a dose of ceftriaxone. LPS inoculated mice were treated with ATL313 or PBS. Serum cytokines and chemokines were measured sequentially at 1, 2, 4, 8, and 24 hours after LPS was administered. In survival studies, mice were followed until death or for 7 days.. There was a significant survival benefit in mice infected with live E. coli (100% vs. 20%, p = 0.013) or S. aureus (60% vs. 20%, p = 0.02) when treated with ATL313 in conjunction with an antibiotic versus antibiotic alone. ATL313 also improved survival from endotoxic shock when compared to PBS treatment (90% vs. 40%, p = 0.005). The serum concentrations of TNF-alpha, MIP-1 alpha, MCP-1, IFN-gamma, and IL-17 were decreased by ATL313 after LPS injection (p < 0.05). Additionally, ATL313 increased the concentration of IL-10 under the same conditions (p < 0.05). Circulating white blood cell concentrations were higher in ATL313 treated animals (p < 0.01).. Further studies are warranted to determine the clinical utility of ATL313 as a novel treatment for sepsis.

Topics: Animals; Anti-Inflammatory Agents; Ceftriaxone; Cytokines; Disease Models, Animal; Escherichia coli Infections; Female; Inflammation; Leukocytes; Lipopolysaccharides; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Piperidines; Receptor, Adenosine A2A; Sepsis; Staphylococcal Infections; Survival Analysis

The chemico-physical data and antimicrobial activities are described of a new series of 2-nitroimidazole derivatives prepared by condensing 1-methyl-2-nitroimidazole-5-carboxaldehyde with N-substituted hydroxylamines, N-aminopiperazines and N-aminopiperidines.

Topics: Animals; Anti-Bacterial Agents; Bacteria; Escherichia coli Infections; Mice; Nitroimidazoles; Piperazines; Piperidines; Staphylococcal Infections; Structure-Activity Relationship

Topics: Animals; Bacteria; Drug Resistance, Microbial; Escherichia coli Infections; Mice; Microbial Sensitivity Tests; Nalidixic Acid; Piperidines; Rifampin; Staphylococcal Infections