Search Results for: bacteri resist

Author: Zaika, L.L.; Kissinger, J.C.; Wasserman, A.E. Description: Increasing concentrations (0.5–8g/liter) of oregano, rosemary, sage, and thyme progressively delayed growth and acid production by Lactobacillus plantarum and Pediococcus acidilactici in a liquid medium. After the bacteriostatic activity was overcome, all four herbs strongly stimulated acid production. The relative inhibitory effect of the herbs toward both microorganisms was oregano ≫ rosemary = sage gt; thyme. L. plantarum was more resistant than P. acidilactici to the toxic effect of the herbs. Organisms from cultures exhibiting delayed fermentation in the presence of sublethal concentrations of an herb, when subcultured into fresh…

Author: Lam, S.J.; O’Brien-Simpson, N.M.; Pantarat, N.; Sulistio, A.; Wong, E.H.H.; Chen, Y.-Y.; Lenzo, J.C.; Holden, J.A.; Blencowe, A.; Reynolds, E.C.; Qiao, G.G. Description: With the recent emergence of reports on resistant Gram-negative ‘superbugs’, infections caused by multidrug-resistant (MDR) Gram-negative bacteria have been named as one of the most urgent global health threats due to the lack of effective and biocompatible drugs. Here, we show that a class of antimicrobial agents, termed ‘structurally nanoengineered antimicrobial peptide polymers’ (SNAPPs) exhibit sub-muM activity against all Gram-negative bacteria tested, including ESKAPE and colistin-resistant…

Author: Bai, X.; Ma, X.; Xu, F.; Li, J.; Zhang, H.; Xiao, X. Description: Two waterworks, with source water derived from the Huangpu or Yangtze River in Shanghai, were investigated, and the effluents were plate-screened for antibiotic-resistant bacteria (ARB) using five antibiotics: ampicillin (AMP), kanamycin (KAN), rifampicin (RFP), chloramphenicol (CM) and streptomycin (STR). The influence of water treatment procedures on the bacterial antibiotic resistance rate and the changes that bacteria underwent when exposed to the five antibiotics at concentration levels ranging from 1 to 100 mug/mL were studied. Multi-drug resistance…

Author: Wilson, D.N. Description: The ribosome is one of the main antibiotic targets in the bacterial cell. Crystal structures of naturally produced antibiotics and their semi-synthetic derivatives bound to ribosomal particles have provided unparalleled insight into their mechanisms of action, and they are also facilitating the design of more effective antibiotics for targeting multidrug-resistant bacteria. In this Review, I discuss the recent structural insights into the mechanism of action of ribosome-targeting antibiotics and the molecular mechanisms of bacterial resistance, in addition to the approaches that are being pursued for the…

Author: Samson, J.E.; Magadan, A.H.; Sabri, M.; Moineau, S. Description: Bacteria and their viral predators (bacteriophages) are locked in a constant battle. In order to proliferate in phage-rich environments, bacteria have an impressive arsenal of defence mechanisms, and in response, phages have evolved counter-strategies to evade these antiviral systems. In this Review, we describe the various tactics that are used by phages to overcome bacterial resistance mechanisms, including adsorption inhibition, restriction-modification, CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR-associated proteins) systems and abortive infection. Furthermore, we consider how these observations have…

Author: Sengeløv, G. Description: Resistance to tetracycline, macrolides and streptomycin was measured for a period of 8 months in soil bacteria obtained from farmland treated with pig manure slurry. This was done by spread plating bacteria on selective media (Luria Bertani (LB) medium supplemented with antibiotics). To account for seasonal variations in numbers of soil bacteria, ratios of resistant bacteria divided by total count on nonselective plates were calculated. Soil samples were collected from four different farms and from a control soil on a fifth farm. The control soil was…

Author: Glibota, Nicolas; Grande Burgos, Ma Jose; Galvez, Antonio; Ortega, Elena Description: BACKGROUND: Heavy metal pollution may act as persistent selective pressure that favors the spread of antimicrobial resistance in natural environments. The aim of this study was to isolate and identify metal-tolerant bacteria from soils in olive tree fields routinely treated with copper-derived compounds and to evaluate the tolerance of bacterial strains to other metals and their resistance to clinically relevant antibiotics. RESULTS: Five hundred and ninety-five bacterial isolates from 45 olive tree agricultural fields were studied. Minimum inhibitory…

Author: Spellberg, B.; Shlaes, D. Description: As a result of declining new antibacterial approvals and rising antibiotic resistance, society clearly needs new treatments for bacterial infections. Specific areas of unmet need evolve over time owing to changes in resistance patterns and treatment strategies. Our goal here is to describe and prioritize the current areas of greatest unmet need for new antibacterial development based on an understanding of the most serious treatment challenges facing patients and their providers today. Subject headings: Animals; Anti-Bacterial Agents/pharmacology/therapeutic use; Bacterial Infections/drug therapy/epidemiology; Drug Design; Drug…

Author: Luby, E.M.; Moorman, T.B.; Soupir, M.L. Description: Application of manure from swine treated with antibiotics introduces antibiotics and antibiotic resistance genes to soil with the potential for further movement in drainage water, which may contribute to the increase in antibiotic resistance in non-agricultural settings. We compared losses of antibiotic-resistant Enterococcus and macrolide-resistance (erm and msrA) genes in water draining from plots with or without swine manure application under chisel plow and no till conditions. Concentrations of ermB, ermC and ermF were all >10(9)copies g(-1) in manure from tylosin-treated swine,…

Author: Kim, T.; Bak, G.; Lee, J.; Kim, K.-S. Description: OBJECTIVES: To systematically analyse the interplay between the expression of Hfq-associated small non-coding RNAs (sRNAs) and antibiotic susceptibility in Gram-negative bacteria. METHODS: To identify the roles of sRNAs in the antibiotic susceptibility of Escherichia coli and Salmonella species, susceptibility tests, growth analyses and viability assays were performed using E. coli Hfq-associated sRNAs from overexpression libraries. Prediction, susceptibility testing of gene knockouts and expression analysis of target genes under conditions of sRNA overexpression or knockout were performed to identify candidate targets…