ABSTRACT We have developed a bioluminescent whole-cell biosensor that can be incorporated into biofilm ecosystems. RM4440 is Pseudomonas aeruginosa FRD1 derivative carries plasmid-based recA-luxCDABE fusion. immobilized in an alginate matrix to simulate biofilm, and we studied its response UV radiation damage. The showed protective property by physical shielding against C, B, A. Absorption of light the translated higher survival rate than observed with planktonic cells at similar input...

We investigated indole-3-acetic acid (IAA) production by 57 pathovars of Pseudomonas syringae and related species. Most those analyzed produced IAA, especially in the presence tryptophan. Eight strains high IAA concentrations absence Trp. The iaaM iaaH genes P. savastanoi pv. were detected a limited number only, including eight above-mentioned strains. Thus, synthesis most assayed species does not involve highly similar to iaaH. In contrast, iaaL gene encoding an IAA-lysine synthase was...

ABSTRACT The accessory gene regulator ( agr ) and the staphylococcal sar are central regulatory elements that control production of Staphylococcus aureus virulence factors. To date, functions these loci have been defined almost exclusively using RN6390, which is representative laboratory strain 8325-4. However, RN6390 was recently shown to a mutation in rsbU results phenotype resembling sigB mutant (I. Kullik et al., J. Bacteriol. 180:4814–4820, 1998). For reason, it remains unclear whether...

Abstract New methacrylate monomers containing pendant quaternary ammonium moieties based on 1,4‐diazabicyclo‐[2.2.2]‐octane (DABCO) were synthesized. The DABCO group contains either a butyl or hexyl comprising the hydrophobic segment of and one tether to moiety. homopolymerized in water by using 2,2′‐azobis(2‐methylpropionamide) dihydrochloride (V‐50) as an initiator. polymers characterized elemental analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), FTIR,...

Staphylococcus aureus possesses 16 two-component systems (TCSs), two of which (GraRS and NsaRS) belong to the intramembrane-sensing histidine kinase (IM-HK) family, is conserved within firmicutes. NsaRS has recently been documented as being important for nisin resistance in S. . In this study, we present a characterization reveal that, with other IM-HK TCSs, it responds disruptions cell envelope. Analysis using lacZ reporter–gene fusion demonstrated that nsaRS expression upregulated by...

Naturally occurring antimicrobial peptides (AMPs) display the ability to eliminate a wide variety of bacteria, without toxicity host eukaryotic cells. Synthetic polymers containing moieties mimicking lysine and arginine components found in AMPs have been reported show effectiveness against specific with mechanism activity purported depend on nature amino acid mimic. In an attempt incorporate both acids into single water-soluble copolymer, series copolymers aminopropyl methacrylamide (APMA)...

Abstract New water‐soluble methacrylate polymers with pendant quaternary ammonium (QA) groups were synthesized and used as antibacterial materials. The QA obtained by the reaction of alkyl halide a previously functional homopolymer various tertiary amines containing 12‐, 14‐, or 16‐carbon chains. structures polymer confirmed Fourier transform infrared 1 H 13 C NMR. degree conversion halides to sites in each was determined NMR be over 90% all cases. number‐average molecular weight...

A novel methacrylate monomer containing a quinolone moiety was synthesized and homopolymerized in N,N-dimethylformamide (DMF) by using azobisisobutyronitrile (AIBN) as an initiator. The new copolymerized with poly(ethylene glycol) methyl ether (MPEGMA) DMF the same monomer, homopolymer, copolymer were characterized elemental analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), size exclusion chromatography (SEC), FTIR, (13)C NMR, (1)H NMR. antibacterial...

We recently demonstrated that mutation of sarA in clinical isolates Staphylococcus aureus results a phenotype is distinct by comparison to mutants generated the laboratory strain RN6390 (J. S. Blevins, K. E. Beenken, M. O. Elasri, B. Hurlburt, and Smeltzer, Infect. Immun. 70:470-480, 2002). This raises possibility studies demonstrating are attenuated do not accurately reflect role pathogenesis staphylococcal disease. To test this hypothesis, we used murine model musculoskeletal infection...

Diclofenac is a non-steroidal anti-inflammatory drug (NSAID) which has been shown to increase the susceptibility of various bacteria antimicrobials and demonstrated have broad antimicrobial activity. This study describes transcriptome alterations in S. aureus strain COL grown with diclofenac characterizes effects this NSAID on antibiotic laboratory, clinical reduced-susceptibility (DcRS) strains. Transcriptional response growth were measured using gene expression microarrays quantitative...

These studies illustrate synthetic paths to covalently attach T1 and Φ11 bacteriophages (phages) inert polymeric surfaces while maintaining the bacteriophage's biological activities capable of killing deadly human pathogens. The first step involved formation acid (COOH) groups on polyethylene (PE) polytetrafluoroethylene (PTFE) using microwave plasma reactions in presence maleic anhydride, followed by covalent attachment species via primary amine groups. phages effectively retain their...

Community-acquired, methicillin-resistant Staphylococcus aureus strains often cause localized infections in immunocompromised hosts, but some show enhanced virulence leading to severe even among healthy individuals with no predisposing risk factors. The genetic basis for this has yet be determined. S. possesses a wide variety of factors, the expression which is carefully coordinated by regulators. Several regulators have been well characterized, others thoroughly investigated. Previously, we...

Staphylococcus aureus has evolved a complex regulatory network that controls multitude of defense mechanisms against the deleterious effects oxidative stress stimuli, subsequently leading to pathogen's survival and persistence in hosts. Previously, we characterized msaABCR operon as regulator virulence, antibiotic resistance, formation persister cells S. Deletion resulted downregulation several genes involved resistance stress. Notably, those included carotenoid biosynthetic ohr gene, which...

Abstract A series of statistical copolymers derived from 2‐(dimethylamino)ethyl methacrylate with four different hydrophobic comonomers (ethyl, butyl, cyclohexyl, and octyl methacrylates) have been prepared via conventional free radical copolymerization under bulk conditions. The subsequently modified, 1,3‐propanesultone to yield the corresponding polysulfoproylbetaine derivatives. Those exhibiting requisite aqueous solubility screened respect their antimicrobial activity against two common...

A new methacrylamide monomer (MAMP) containing a pyridine moiety was synthesized by reacting methacrylic anhydride and 3-(aminomethyl) pyridine. The homopolymerized in 1,4-dioxane copolymerized with N-isopropyl acrylamide DMF at two different compositions using AIBN as an initiator. groups of the homopolymer copolymers were reacted various bromoalkanes 12, 14, 16 carbon alkyl chains to obtain polymers pendant pyridinium groups. characterized elemental analysis, NMR, FTIR, SEC, TGA, DSC....

Staphylococcus aureus is an important human pathogen, causing a wide variety of diseases ranging from superficial skin infections to severe life threatening infections. S. one the leading causes nosocomial Its ability resist multiple antibiotics poses growing public health problem. In order understand mechanism pathogenesis aureus, several global expression profiles have been developed. These transcriptional included regulatory mutants and growth wild type under different conditions. The...

The staphylococcal accessory regulator (sarA) plays a central role in the regulation of virulence Staphylococcus aureus. To date, studies involving sarA have focused on its activity as global that modulates transcription wide variety genes (>100) and virulence. However, there is also evidence to suggest existence elements modulate SarA production and/or function. A reporter system was developed identify such elements, new gene, msa (SA1233), mutation which results reduced expression SarA,...

Abstract Background Staphylococcus aureus is an important pathogen that forms biofilms. The global regulator sarA essential for biofilm formation. Since the modulator of ( msa ) required full expression and regulates several virulence factors, we examined capacity mutant to form biofilm. Results We found mutation results in reduced formed a weak unstable able adhere surfaces begins but fails mature indicating defect accumulation stage not primary adhesion. Conclusion gene plays role...

The limited availability of genomic tools and data for nonmodel species impedes computational systems biology approaches in organisms. Here we describe the development, functional annotation, utilization avian wildlife Northern bobwhite (Colinus virginianus) to determine molecular impacts exposure 2,6-dinitrotoluene (2,6-DNT), a field contaminant military concern. Massively parallel pyrosequencing normalized multitissue library cDNAs yielded 71,384 unique transcripts that were annotated with...

Staphylococcus aureus produces several virulence factors that allow it to cause a variety of infections. One the major is capsule, which contributes survival pathogen within host as way escape phagocytosis. The production capsular polysaccharide encoded in 16 gene operon, regulated response environmental stimuli including nutrient availability. For instance, capsule produced late- and post-exponential growth phases, but not early- or mid-exponential phase. Several regulators are involved...

Persister cells comprise a phenotypic variant that shows extreme antibiotic tolerance resulting in treatment failures of bacterial infections. While this phenomenon has posed great threat public health, mechanisms underlying their formation Staphylococcus aureus remain largely unknown. Increasing evidences the presence persister recalcitrant infections underscores urgency to unravel mechanism by which these develop. Previously, we characterized msaABCR operon plays roles regulation...

In Staphylococcus aureus, the transcription factor CodY modulates expression of hundreds genes, including most virulence factors, in response to availability key nutrients like GTP and branched-chain amino acids. Despite numerous studies examining how controls gene directly or indirectly, virtually nothing is known about extent which exerts its effect through small regulatory RNAs (sRNAs). Herein, we report first set sRNAs under control CodY. We reveal that staphylococcal sRNA RsaD...