Aeromonas salmonicida subsp. is a Gram-negative bacterium that the causative agent of furunculosis, bacterial septicaemia salmonid fish. While other species are opportunistic pathogens or found in commensal symbiotic relationships with animal hosts, A. causes disease healthy The genome sequence was determined to provide better understanding virulence factors used by this pathogen infect nucleotide sequences A449 chromosome and two large plasmids characterized. 4,702,402 bp encodes 4388...

Although the structural gene for diphtheria toxin, tox, is carried by a family of closely related corynebacteriophages, regulation tox expression controlled, to large extent, its bacterial host Corynebacterium diphtheriae. Optimal yields products are obtained only when iron becomes growth-rate-limiting substrate. Previous studies suggest that mediated through an iron-binding aporepressor. To facilitate molecular cloning regulatory element from genomic libraries C. diphtheriae, we constructed...

We report the characterization and determination of 2,6-dichloro-1,4-benzoquinone three new disinfection byproducts (DBPs): 2,6-dichloro-3-methyl-1,4-benzoquinone, 2,3,6-trichloro-1,4-benzoquinone, 2,6-dibromo-1,4-benzoquinone. These haloquinones are suspected bladder carcinogens likely produced during drinking water treatment. However, detection these is challenging, consequently, they have not been characterized as DBPs until recently. developed an electrospray ionization tandem mass...

N-Nitrosodimethylamine (NDMA), a member of group probable human carcinogens, has been detected as disinfection byproduct (DBP) in drinking water supplies Canada and the United States. To comprehensively investigate occurrence possible nitrosamines supplies, liquid chromatography-tandem mass spectrometry technique was developed to detect both thermally stable unstable nitrosamines. This consisted solid-phase extraction (SPE), chro matography (LC) separation, tandem quadrupole linear ion trap...

Formation of nine N-nitrosamines has been investigated when seven different source waters representing various qualities were each treated with eleven bench-scale disinfection processes, without addition nitrosamine precursors. These treatments included chlorine (OCl−), chloramine (NH2Cl), dioxide (ClO2), ozone (O3), ultraviolet (UV), advanced oxidation processes (AOP), and combinations. The total organic carbon (TOC) the ranged from 2 to 24 mg·L−1. disinfected water samples untreated...

Coming clean? Liquid chromatography–ESI tandem mass spectrometry is used to detect 2,6-dichloro-1,4-benzoquinone (see picture) in drinking water treated with chlorine or chloramine.

Halobenzoquinones (HBQs) are a class of disinfection byproducts (DBPs) health relevance. In this study, we aimed to uncover which HBQs present in swimming pools. To achieve goal, developed new method capable determining eight while overcoming matrix effects reliable quantification. The provided reproducible and quantitative recovery (67–102%) detection limits 0.03–1.2 ng/L for all HBQs. Using method, investigated water samples from 10 pools found 2,6-dichloro-1,4-benzoquinone (2,6-DCBQ) the...

Type IV pili play an important role in bacterial adhesion, motility, and biofilm formation. Here we present high-resolution atomic force microscopy (AFM) images of type from Pseudomonas aeruginosa bacteria. An individual pilus ranges length 0.5 to 7 microm has a diameter 4 6 nm, although often, bundles which the filaments differed both were seen. By attaching bacteria AFM tips, it was possible fasten mica surfaces by tethers. Force spectra tethered gave rupture forces 95 pN. The slopes...

The structural gene for diphtheria toxin, tox, has been modified at its Sph I site by the introduction of an oligonucleotide linker encoding a unique Pst restriction endonuclease and synthetic alpha-melanocyte-stimulating hormone (alpha-MSH). resulting fusion directs expression toxin-related alpha-MSH hybrid protein in which toxin receptor-binding domain replaced with sequences. chimeric partially purified from periplasmic extracts recombinant Escherichia coli K-12 found to be selectively...

Since the 1974 discovery of trihalomethanes as disinfection by-products (DBPs) in drinking water, regulatory and public health focus has been primarily directed at halogenated compounds, even though it is well established that chlorination chloramination also produce non-halogenated DBPs. Specific DBPs could reasonably explain correlation some adverse outcomes with consumption disinfected water a number epidemiologic studies have yet to be identified. We therefore explored an emerging class...

We report here the characterization of twelve halobenzoquinones (HBQs) using electrospray ionization (ESI) high resolution quadrupole time-of-flight mass spectrometry. The negative ESI spectra HBQs formed two parent ions, [M + H(+) 2e(-)], and radical M(-•). intensities these ions are dependent on their chemical structures instrumental parameters such as source temperature flow rate. characteristic were used to develop an ultra pressure liquid chromatography-tandem spectrometry (UPLC-MS/MS)...

Despite the significant morbidity and mortality associated with pheochromocytoma paraganglioma, little is known about their epidemiology. The primary objective was to determine incidence of paraganglioma in an ethnically diverse population. A secondary develop validate algorithms for case detection using laboratory administrative data.Population-based cohort study Alberta, Canada from 2012 2019.Patients or were identified linked databases clinical records. Annual rates per 100 000 people...

The recently described type III secretion system (TTSS) of Aeromonas salmonicida subsp. has been linked to virulence in salmonids. In this study, three TTSS effector genes, aexT, aopH or aopO, were inactivated by deletion, as was ascC, the gene encoding outer-membrane pore apparatus. Effects on assayed live challenge Atlantic salmon (Salmo salar). DeltaascC mutant strain avirulent both intraperitoneal (i.p.) injection and immersion, did not appear establish a clinically inapparent infection...

Aeromonas salmonicida subsp. salmonicida, a bacterial pathogen of Atlantic salmon, has no visible pili, yet its genome contains genes for three type IV pilus systems. One system, Tap, is similar to the Pseudomonas aeruginosa Pil and second, Flp, resembles Actinobacillus actinomycetemcomitans Flp pilus, while third homology mannose-sensitive hemagglutinin Vibrio cholerae. The latter system likely nonfunctional since eight genes, including gene encoding main pilin subunit, are deleted compared...

Halobenzoquinones (HBQs) are a group of emerging disinfection byproducts (DBPs) found in treated drinking water. Because the use UV treatment for is becoming more widespread, it important to understand how HBQs may be removed or changed due irradiation. Water samples containing four HBQs, 2,6-dichloro-1,4-benzoquinone (DCBQ), 2,3,6-trichloro-1,4-benzoquinone (TCBQ), 2,6-dichloro-3-methyl-1,4-benzoquinone (DCMBQ), and (DBBQ), were using modified bench scale collimated beam device, mimicking...

We have used site-directed mutagenesis to examine the role played by Arg191, Arg193, and Arg194 of fusion toxin DAB486-IL-2 in intoxication high affinity interleukin-2 receptor-bearing T-lymphocytes. These arginine residues are positioned proteolytically sensitive 14-amino acid loop subtended disulfide bond between Cys187 Cys202 this toxin. was formed genetic substitution native diphtheria receptor binding domain with human (Williams, D.P., Parker, K., Bacha, P., Bishai, W., Borowski, M.,...

The structural gene for diphtheria toxin, tox, is carried by a family of closely related corynebacteriophages; however, the regulation tox expression controlled Corynebacterium diphtheriae-encoded regulatory element, dtxR. molecular cloning and sequence analysis dtxR was recently described. Previous studies have suggested that DtxR-mediated operator involves formation an iron-repressor complex, which specifically binds to operator. We expressed purified DtxR from recombinant Escherichia...

N-nitrosodiphenylamine (NDPhA) is a disinfection byproduct (DBP) in drinking water. However, it not known what governs the formation of NDPhA and which precursor(s) raw water responsible for its formation. We report here diphenylamine (DPhA) as key precursor NDPhA, we describe effect pH chloramination conditions on NDPhA. To identify precursors samples were collected from same system was previously detected. Analysis showed presence 1.3 ng/L DPhA no detectable Seven hours after treatment...

The type II secretion system (T2SS) functions as a transport mechanism to translocate proteins from the periplasm extracellular environment. ExeA homologue in Aeromonas hydrophila, GspA(Ah), is an ATPase that interacts with peptidoglycan and forms inner membrane complex ExeB (GspB(Ah)). may be required generate space mesh necessary for assembly of megadalton-sized ExeD (GspD(Ah)) secretin multimer outer membrane. In this study, requirement GspAB T2SS Vibrio species was investigated. We have...