Biophysical analysis of the Mycobacteria tuberculosis peptide binding protein DppA reveals a stringent peptide binding pocket.

The peptide binding protein DppA is an ABC transporter found in prokaryotes that has the potential to be used as drug delivery tool for hybrid antibiotic compounds. Understanding the motifs and structures that bind to DppA is critical to the development of these bivalent compounds. This study focused on the biophysical analysis of the MtDppA from M.

17-DMAG dually inhibits Hsp90 and histone lysine demethylases in alveolar rhabdomyosarcoma.

Histone lysine demethylases (KDMs) play critical roles in oncogenesis and therefore may be effective targets for anticancer therapy. Using a time-resolved fluorescence resonance energy transfer demethylation screen assay, in combination with multiple orthogonal validation approaches, we identified geldanamycin and its analog 17-DMAG as KDM inhibitors. In addition, we found that these Hsp90 inhibitors increase degradation of the alveolar rhabdomyosarcoma (aRMS) driver oncoprotein PAX3-FOXO1 and induce the repressive epigenetic mark H3K9me3 and H3K36me3 at genomic loci of PAX3-FOXO1 targets.

Discovery and Characterization of the Antimetabolite Action of Thioacetamide-Linked 1,2,3-Triazoles as Disruptors of Cysteine Biosynthesis in Gram-Negative Bacteria.

Increasing rates of drug-resistant Gram-negative (GN) infections, combined with a lack of new GN-effective antibiotic classes, are driving the need for the discovery of new agents. Bacterial metabolism represents an underutilized mechanism of action in current antimicrobial therapies. Therefore, we sought to identify novel antimetabolites that disrupt key metabolic pathways and explore the specific impacts of these agents on bacterial metabolism.

Next Generation of Tn-Based Single-Copy Insertion Elements for Use in Multi- and Pan-Drug-Resistant Strains of Acinetobacter baumannii.

The purpose of this study was to create single-copy gene expression systems for use in genomic manipulations of multidrug-resistant (MDR) and extensively drug-resistant (XDR) clinical isolates of In this study, mini-Tn vectors with zeocin and apramycin selection markers were created by cloning the and genes, respectively, enabling either inducible gene expression (pUC18T-mini-TnT-Zeo-LAC and pUC18T-mini-TnT-Apr-LAC) or expression from native or constitutive promoters (pUC18T-mini-TnT-Zeo and pUC18T-mini-TnT-Apr). The selection markers of these plasmids are contained within a Flp recombinase target (FRT) cassette, which can be used to obtain unmarked mini-Tn insertions upon introduction of a source of Flp recombinase. To this end, site-specific excision vectors pFLP2A and pFLP2Z (containing apramycin and zeocin selection markers, respectively) were created in this study as an accessory to the mini-Tn vectors described above.

New β-lactam - Tetramic acid hybrids show promising antibacterial activities.

β-Lactams are the most important class of antibiotics, for which the emergence of resistance threatens their utility. As such, we explored the extent to which the tetramic acid motif, frequently found in naturally occurring antibiotics, can be used to generate novel β-lactam antibiotics with improved antibacterial activity. We synthesized new ampicillin - tetramic acid, cephalosporin - tetramic acid, and cephamycin - tetramic acid analogs and evaluated their activities against problematic Gram-positive and Gram-negative pathogens.

Effect of Incubation Temperature on Antibiotic Resistance and Virulence Factors of Acinetobacter baumannii ATCC 17978.

is a notorious opportunistic pathogen that is prevalent mainly in hospital settings. The ability of to adapt and to survive in a range of environments has been a key factor for its persistence and success as an opportunistic pathogen. In this study, we investigated the effect of temperature on the clinically relevant phenotypes displayed by at 37°C and 28°C.

Prevalence of antibiotic resistance genes in bacterial communities associated with Cladophora glomerata mats along the nearshore of Lake Ontario.

The alga Cladophora glomerata can erupt in nuisance blooms throughout the lower Great Lakes. Since bacterial abundance increases with the emergence and decay of Cladophora, we investigated the prevalence of antibiotic resistance (ABR) in Cladophora-associated bacterial communities up-gradient and down-gradient from a large sewage treatment plant (STP) on Lake Ontario. Although STPs are well-known sources of ABR, we also expected detectable ABR from up-gradient wetland communities, since they receive surface run-off from urban and agricultural sources.

Characteristics of road traffic accident casualties admitted to a tertiary care hospital in Sri Lanka.

The mortality and morbidity of road traffic accidents (RTA) is increasing in the South Asian region, including Sri Lanka. Therefore, the demographic factors, types of vehicles involved, and the severity of injuries sustained in RTA was studied. Age, gender, and details of the incident of all patients admitted to hospital following a RTA, between January 2007 and August 2012, were obtained by interview.

Multi-omics approach to study global changes in a triclosan-resistant mutant strain of Acinetobacter baumannii ATCC 17978.

Acinetobacter baumannii AB042, a triclosan-resistant mutant strain, was examined for modulated gene expression using whole-genome sequencing, transcriptomics and proteomics in order to understand the mechanism of triclosan resistance as well as its impact on A. baumannii. Data revealed modulated expression of the fatty acid metabolism pathway, co-factors known to play a role in the synthesis of fatty acids, as well as several transcriptional regulators.

Isolation and Characterization of Recovered from Selective Medium.

, a Gram-negative opportunistic pathogen, is known to cause multidrug resistant infections. This organism has primarily been isolated from clinical environments and its environmental reservoirs remain largely unknown. In the present study, we recovered seven isolates of growing under conditions selective for spp.

Hybrid Antibiotic Overcomes Resistance in P. aeruginosa by Enhancing Outer Membrane Penetration and Reducing Efflux.

Therapeutic interventions to treat multidrug-resistant (MDR) Pseudomonas aeruginosa infections are severely limited and often require the use of colistin as drug of last resort. The major challenges impeding the development of novel antipseudomonal agents are the lack of cell penetration and extensive efflux. We have discovered a tobramycin-moxifloxacin hybrid core structure which enhances outer membrane permeability and reduces efflux by dissipating the proton motive force of the cytoplasmic membrane in P.

Detection of Antibiotic Resistance Genes in Source and Drinking Water Samples from a First Nations Community in Canada.

Unlabelled: Access to safe drinking water is now recognized as a human right by the United Nations. In developed countries like Canada, access to clean water is generally not a matter of concern. However, one in every five First Nations reserves is under a drinking water advisory, often due to unacceptable microbiological quality.

KatG and KatE confer Acinetobacter resistance to hydrogen peroxide but sensitize bacteria to killing by phagocytic respiratory burst.

Aims: Catalase catalyzes the degradation of H2O2. Acinetobacter species have four predicted catalase genes, katA, katE, katG, and katX. The aims of the present study seek to determine which catalase(s) plays a predominant role in determining the resistance to H2O2, and to assess the role of catalase in Acinetobacter virulence.

Adjuvants Based on Hybrid Antibiotics Overcome Resistance in Pseudomonas aeruginosa and Enhance Fluoroquinolone Efficacy.

The use of adjuvants that rescue antibiotics against multidrug-resistant (MDR) pathogens is a promising combination strategy for overcoming bacterial resistance. While the combination of β-lactam antibiotics and β-lactamase inhibitors has been successful in restoring antibacterial efficacy in MDR bacteria, the use of adjuvants to restore fluoroquinolone efficacy in MDR Gram-negative pathogens has been challenging. We describe tobramycin-ciprofloxacin hybrid adjuvants that rescue the activity of fluoroquinolone antibiotics against MDR and extremely drug-resistant Pseudomonas aeruginosa isolates in vitro and enhance fluoroquinolone efficacy in vivo.

Penetrative Injury to the Face Resulting in Delayed Death After Rupture of a Cavernous Sinus Aneurysm on the Contralateral Side.

Delayed deaths after assault give rise to medicolegal issues such as whether the assault was directly responsible, did it contribute or was it totally unrelated to the death. We present the case of a patient who sustained penetrative trauma to the face resulting in the formation of a contralateral, carotid-cavernous fistula, which resulted in aneurysm formation, delayed rupture, and death. A literature search failed to find a similar case.

Triclosan can select for an AdeIJK-overexpressing mutant of Acinetobacter baumannii ATCC 17978 that displays reduced susceptibility to multiple antibiotics.

In order to determine if triclosan can select for mutants of Acinetobacter baumannii ATCC 17978 that display reduced susceptibilities to antibiotics, we isolated a triclosan-resistant mutant, A. baumannii AB042, by serial passaging of A. baumannii ATCC 17978 in growth medium supplemented with triclosan.

Necrotizing fasciitis and death following an insect bite.

A healthy man who presented to hospital with painful swelling of the left arm following a history of insect (tick) bite developed shock and died within 48 hours. The postmortem examination revealed swelling and desquamation of skin and erythema on the left arm extending below the elbow. The subcutaneous tissue was necrotic with healthy underlying muscles.

Resistance-Nodulation-Division Multidrug Efflux Pumps in Gram-Negative Bacteria: Role in Virulence.

Resistance-Nodulation-Division (RND) efflux pumps are one of the most important determinants of multidrug resistance (MDR) in Gram-negative bacteria. With an ever increasing number of Gram-negative clinical isolates exhibiting MDR phenotypes as a result of the activity of RND pumps, it is clear that the design of novel effective clinical strategies against such pathogens must be grounded in a better understanding of these pumps, including their physiological roles. To this end, recent evidence suggests that RND pumps play an important role in the virulence of Gram-negative pathogens.

Adrenaline toxicity following accidental administration of the 1:1000 solution during dental procedures: Four case reports.

Four patients aged between 35 and 50 years attended the out patients department of a dental hospital for tooth extraction. Following administration of, what was thought to be the local anesthetic, Lignocaine, to the gum and sub mucosa, they all collapsed. What had, in fact, been injected was 1:1000 adrenaline.

Occlusion of a coronary ostium by an ingrowing endocardial vegetation: a case report.

A 21-year-old primi, with a period of gestation of 35 weeks, was found collapsed in the toilet of a maternity hospital in Colombo, Sri Lanka. She had been admitted five days previously and echocardiography had detected a tight aortic stenosis with grade I aortic regurgitation. At autopsy, the heart showed multiple, large (> 10mm), friable vegetations on a stenosed, bicuspid aortic valve.