155 research outputs found

    The housefly Musca domestica as a mechanical vector of Clostridium difficile

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    Background - Clostridium difficile is a bacterial healthcare-associated infection that may be transferred by houseflies (Musca domestica) due to their close ecological association with humans and cosmopolitan nature. Aim - To determine the ability of M. domestica to transfer C. difficile both mechanically and following ingestion. Methods - M. domestica were exposed to independent suspensions of vegetative cells and spores of C. difficile, then sampled on to selective agar plates immediately postexposure and at 1-h intervals to assess the mechanical transfer of C. difficile. Fly excreta was cultured and alimentary canals were dissected to determine internalization of cells and spores. Findings - M. domestica exposed to vegetative cell suspensions and spore suspensions of C. difficile were able to transfer the bacteria mechanically for up to 4 h upon subsequent contact with surfaces. The greatest numbers of colony-forming units (CFUs) per fly were transferred immediately following exposure (mean CFUs 123.8 +/− 66.9 for vegetative cell suspension and 288.2 +/− 83.2 for spore suspension). After 1 h, this had reduced (21.2 +/− 11.4 for vegetative cell suspension and 19.9 +/− 9 for spores). Mean C. difficile CFUs isolated from the M. domestica alimentary canal was 35 +/− 6.5, and mean C. difficile CFUs per faecal spot was 1.04 +/− 0.58. C. difficile could be recovered from fly excreta for up to 96 h. Conclusion - This study describes the potential for M. domestica to contribute to environmental persistence and spread of C. difficile in hospitals, highlighting flies as realistic vectors of this micro-organism in clinical areas

    Note. Colonisation of bench cover materials by Salmonella typhimurium

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    Due to the increasing requirements of food safety, it is of utmost importance to know the mechanisms that can determine the occurrence of the phenomenon commonly assigned by cross contamination, which can be expressed by the transference of harmful substances or microorganisms to the human food chain. This is particularly susceptible during food preparation, because it can occur by the transference of the pathogen microorganisms from food to the surfaces where they had been prepared, and from there to foods initially not contaminated, therefore initiating the cycle. This study attempted to investigate the colonisation by Salmonella typhimurium ATCC 13311 of marble and granite, two materials commonly used as bench covers in kitchens of many countries. These materials were selected because there is a lack of studies in the literature about their ability for bacterial colonisation. In addition, the colonisation of stainless steel (SS) 304, a material usually studied, was also analysed in terms of comparison. Surface hydrophobicity and roughness were determined in order to explain the differences in the extent of adhesion. The results showed that SS was the material with a greater extent of colonisation by S. typhimurium, followed by marble and, almost to the same extent, by granite. S. typhimurium adheres to a greater extent to the most hydrophobic material and to the material with roughest surface.Fundação para a Ciência e a Tecnologia (FCT) - PRAXIS SFRH/BPD/11553/2002, projecto POCI/AGR/59358/200

    Integrated hepatitis C testing and linkage to care at a local health department sexually transmitted disease clinic: Determining essential resources and evaluating outcomes

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    Guidance about integration of comprehensive hepatitis C virus (HCV)-related services in sexually transmitted disease (STD) clinics is limited. We evaluated a federally funded HCV testing and linkage-to-care program at an STD clinic in Durham County, North Carolina. During December 10, 2012, to March 31, 2015, the program tested 733 patients for HCV who reported 1 or more HCV risk factor; 81 (11%) were HCV-infected (ie, HCV antibody-positive and HCV ribonucleic acid-positive). Fifty-one infected patients (63%) were linked to care. We concluded that essential program resources include reflex HCV ribonucleic acid testing; a dedicated bridge counselor to provide test results, health education, and linkage-to-care assistance; and referral relationships for local HCV management and treatment

    Acquisition and retention of Clostridium difficile by Musca domestica larvae and pupae during metamorphosis

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    Background: Transfer of Clostridium difficile by Musca domestica has been demonstrated, revealing their potential for disseminating infection in the hospital environment. Aim: To determine the ability of M. domestica larvae to acquire and retain C. difficile throughout their metamorphosis into adult flies. Methods: Larvae were exposed to spores of C. difficile in a faecal emulsion and examined externally and internally to determine carriage and internalisation of spores through their development to adults. Findings: Larvae harboured C. difficile externally, with means of 21.56 +/- 5.76 CFUs at day zero, 22.44 +/- 9.90 after two days, decreasing to 0.56 +/- 0.34 at day four, with no C. difficile isolated thereafter. The same larvae harboured C. difficile internally, with means of 587.33 +/- 238.29 CFUs at day zero, decreasing to 297.44 +/- 155.21 after two days, decreasing further to 73.67 +/- 46.74 after four days, with no C. difficile isolated thereafter. The zero recovery of C. difficile coincided with the development of M. domestica larvae into pupae. From day six onwards, all larvae had developed into the pupal stage and no C. difficile was recoverable from any pupae. No C. difficile was recovered from adult flies (emerged on day twelve), or empty puparia. Conclusion: Although C. difficile spores are readily acquired and internalised by larvae during feeding, they are not retained through development to adults. Adult flies therefore acquire C. difficile contamination as adults. The potential antimicrobial action of M. domestica larvae and their extracts against C. difficile spores warrants further investigation

    Functional Anatomy of the Female Pelvic Floor

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    The anatomic structures in the female that prevent incontinence and genital organ prolapse on increases in abdominal pressure during daily activities include sphincteric and supportive systems. In the urethra, the action of the vesical neck and urethral sphincteric mechanisms maintains urethral closure pressure above bladder pressure. Decreases in the number of striated muscle fibers of the sphincter occur with age and parity. A supportive hammock under the urethra and vesical neck provides a firm backstop against which the urethra is compressed during increases in abdominal pressure to maintain urethral closure pressures above the rapidly increasing bladder pressure. This supporting layer consists of the anterior vaginal wall and the connective tissue that attaches it to the pelvic bones through the pubovaginal portion of the levator ani muscle, and the uterosacral and cardinal ligaments comprising the tendinous arch of the pelvic fascia. At rest the levator ani maintains closure of the urogenital hiatus. They are additionally recruited to maintain hiatal closure in the face of inertial loads related to visceral accelerations as well as abdominal pressurization in daily activities involving recruitment of the abdominal wall musculature and diaphragm. Vaginal birth is associated with an increased risk of levator ani defects, as well as genital organ prolapse and urinary incontinence. Computer models indicate that vaginal birth places the levator ani under tissue stretch ratios of up to 3.3 and the pudendal nerve under strains of up to 33%, respectively. Research is needed to better identify the pathomechanics of these conditions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72597/1/annals.1389.034.pd

    2022 Upgrade and Improved Low Frequency Camera Sensitivity for CMB Observation at the South Pole

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    Constraining the Galactic foregrounds with multi-frequency Cosmic Microwave Background (CMB) observations is an essential step towards ultimately reaching the sensitivity to measure primordial gravitational waves (PGWs), the sign of inflation after the Big-Bang that would be imprinted on the CMB. The BICEP Array telescope is a set of multi-frequency cameras designed to constrain the energy scale of inflation through CMB B-mode searches while also controlling the polarized galactic foregrounds. The lowest frequency BICEP Array receiver (BA1) has been observing from the South Pole since 2020 and provides 30 GHz and 40 GHz data to characterize the Galactic synchrotron in our CMB maps. In this paper, we present the design of the BA1 detectors and the full optical characterization of the camera including the on-sky performance at the South Pole. The paper also introduces the design challenges during the first observing season including the effect of out-of-band photons on detectors performance. It also describes the tests done to diagnose that effect and the new upgrade to minimize these photons, as well as installing more dichroic detectors during the 2022 deployment season to improve the BA1 sensitivity. We finally report background noise measurements of the detectors with the goal of having photon noise dominated detectors in both optical channels. BA1 achieves an improvement in mapping speed compared to the previous deployment season.Comment: Proceedings of SPIE Astronomical Telescopes + Instrumentation 2022 (AS22

    Search for the doubly heavy baryon Ξbc+\it{\Xi}_{bc}^{+} decaying to J/ψΞc+J/\it{\psi} \it{\Xi}_{c}^{+}

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    A first search for the Ξbc+J/ψΞc+\it{\Xi}_{bc}^{+}\to J/\it{\psi}\it{\Xi}_{c}^{+} decay is performed by the LHCb experiment with a data sample of proton-proton collisions, corresponding to an integrated luminosity of 9fb19\,\mathrm{fb}^{-1} recorded at centre-of-mass energies of 7, 8, and 13TeV13\mathrm{\,Te\kern -0.1em V}. Two peaking structures are seen with a local (global) significance of 4.3(2.8)4.3\,(2.8) and 4.1(2.4)4.1\,(2.4) standard deviations at masses of 6571MeV ⁣/c26571\,\mathrm{Me\kern -0.1em V\!/}c^2 and 6694MeV ⁣/c26694\,\mathrm{Me\kern -0.1em V\!/}c^2, respectively. Upper limits are set on the Ξbc+\it{\Xi}_{bc}^{+} baryon production cross-section times the branching fraction relative to that of the Bc+J/ψDs+B_{c}^{+}\to J/\it{\psi} D_{s}^{+} decay at centre-of-mass energies of 8 and 13TeV13\mathrm{\,Te\kern -0.1em V}, in the Ξbc+\it{\Xi}_{bc}^{+} and in the Bc+B_{c}^{+} rapidity and transverse-momentum ranges from 2.0 to 4.5 and 0 to 20GeV ⁣/c20\,\mathrm{Ge\kern -0.1em V\!/}c, respectively. Upper limits are presented as a function of the Ξbc+\it{\Xi}_{bc}^{+} mass and lifetime.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-005.html (LHCb public pages

    Study of the lineshape of the chi(c1) (3872) state

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    A study of the lineshape of the chi(c1) (3872) state is made using a data sample corresponding to an integrated luminosity of 3 fb(-1) collected in pp collisions at center-of-mass energies of 7 and 8 TeV with the LHCb detector. Candidate chi(c1)(3872) and psi(2S) mesons from b-hadron decays are selected in the J/psi pi(+)pi(-) decay mode. Describing the lineshape with a Breit-Wigner function, the mass splitting between the chi(c1 )(3872) and psi(2S) states, Delta m, and the width of the chi(c1 )(3872) state, Gamma(Bw), are determined to be (Delta m=185.598 +/- 0.067 +/- 0.068 Mev,)(Gamma BW=1.39 +/- 0.24 +/- 0.10 Mev,) where the first uncertainty is statistical and the second systematic. Using a Flatte-inspired model, the mode and full width at half maximum of the lineshape are determined to be (mode=3871.69+0.00+0.05 MeV.)(FWHM=0.22-0.04+0.13+0.07+0.11-0.06-0.13 MeV, ) An investigation of the analytic structure of the Flatte amplitude reveals a pole structure, which is compatible with a quasibound D-0(D) over bar*(0) state but a quasivirtual state is still allowed at the level of 2 standard deviations
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