14 research outputs found
Identification of a major Listeria monocytogenes outbreak clone linked to soft cheese in Northern Italy - 2009-2011
Background: Molecular subtyping and enhanced surveillance in Lombardy region identified a cluster of possibly related listeriosis cases from 2006 to 2010. This cluster grouped 31 isolates that belonged to serotype 1/2a and Sequence Type 38 (ST38) as defined by Multilocus Sequence Typing (MLST).
Methods: Our study expanded the previous investigation to include cases from 2011 to 2014 and used Multi-Virulence- Locus Sequence Typing (MVLST) on all ST38 isolates to better understand their epidemiology and possibly identify a common source outbreak.
Results: Out of 306 L. monocytogenes clinical isolates collected, 43 (14.1%) belonged to ST38 with cases occurring in nine out of twelve Lombardy provinces. The ST38 isolates were split by MVLST into two Virulence Types (VTs): VT80 (n = 12) and VT104 (n = 31). VT104 cases were concentrated between 2009 and 2011 in two provinces, Bergamo and Milan. An epidemiologic investigation was performed and in one case, a matching VT104 isolate was retrieved from a soft cheese sample from a patient's refrigerator.
Conclusions: Our findings revealed a major listeriosis outbreak in Northern Italy linked to soft cheese in 20092011, which went undetected by local health authorities. Our study shows that integrating subtyping methods with conventional epidemiology can help identify the source of L. monocytogenes outbreak clones
On manifolds with nonhomogeneous factors
We present simple examples of finite-dimensional connected homogeneous spaces
(they are actually topological manifolds) with nonhomogeneous and nonrigid
factors. In particular, we give an elementary solution of an old problem in
general topology concerning homogeneous spaces
Proposal of an experimental scheme for realising a translucent eavesdropping on a quantum cryptographic channel
Purpose of this paper is to suggest a scheme, which can be realised with
today's technology and could be used for entangling a probe to a photon qubit
based on polarisation. Using this probe a translucent or a coherent
eavesdropping can be performed.Comment: in pres
Molecular characterization of Listeria monocytogenes isolates from pregnancy-related cases in Northern Italy
Background and aims
Invasive listeriosis usually affects pregnant, newborns, the elderly, and immunocompromised individuals. In pregnant women Listeria monocytogenes may cause abortion, fetal death, or neonatal morbidity. The aim of this study was to characterize pregnancy-related isolates of L. monocytogenes observed in Lombardy, Italy, from 2005 to 2012.
Methods
Intragenic regions of six virulence and seven housekeeping genes of 19 pregnancy-related isolates were amplified and analyzed. Virulence gene sequences were compared to available data obtained from isolates representing major human listeriosis outbreaks worldwide, and other unrelated isolates. Housekeeping alleles and STs were assigned by the Pasteur Institute, France.
Results
On the whole, 15 VTs and 14 STs were identified. Based on the MVLST results 37% of isolates (n=7) belonged to one the seven currently known ECs of L. monocytogenes. Interestingly, two ECI isolates (VT20) corresponded to ST1 and ST595 both included in the same Clonal Complex (CC) 1 which includes also VT87 (ST1). A similar picture was recorded for CC 101 which included ST38 (n=2) and ST101 (n=1) that have been typed as VT80 and 100, respectively, presenting just a SNP for both the typing protocols. Eight isolates proved to belong to previously observed VTs-STs (Table 1).
Conclusions
Typing of L. monocytogenes isolates analyzed herein from apparently sporadic pregnancy-related cases of listeriosis showed a possible relation between them. Such data will be important to better determine how ECs are distributed and trace their long-term spread
The peppermint breath test : A benchmarking protocol for breath sampling and analysis using GC-MS
Exhaled breath contains hundreds of volatile organic compounds (VOCs) which offer the potential for diagnosing and monitoring a wide range of diseases. As the breath research field has grown, sampling and analytical practices have become highly varied between groups. Standardisation would allow meta-analyses of data from multiple studies and greater confidence in published results. Washout of VOCs from ingestion into the blood and subsequently breath could provide data for an initial assessment of inter-group performance. The Peppermint Initiative has been formed to address this task of standardisation. In the current study we aimed to generate initial benchmark values for thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) analysis of breath samples containing peppermint-derived VOCs using data from three independent European research groups. Initially, headspace analysis of peppermint oil capsules was performed to determine compounds of interest. Ten healthy participants were recruited by each three groups across Europe. The standard Peppermint protocol was followed. In brief, each participant provided a baseline breath sample prior to taking a peppermint capsule, with further samples collected at 60, 90, 165, 285 and 360 min following ingestion. Sampling and analytical protocols were different for each group, in line with their usual practice. Samples were analysed by TD-GC-MS and benchmarking values determined for the time taken for detected peppermint VOCs to return to baseline values. Sixteen compounds were identified in the capsule headspace, and all were confirmed in breath following ingestion of the peppermint capsules. Additionally, 2,3-dehydro-1,8-cineole was uniquely found in the breath samples, with a washout profile that suggested it was a product of metabolism of peppermint compounds. Five compounds (α-pinene, β-pinene, eucalyptol, menthol and menthone) were quantified by all three groups. Differences were observed between the groups, particularly for the recovery of menthone and menthol. The average time taken for VOCs to return to baseline was selected as the benchmark and were 377, 423, 533, 418 and 336 min for α-pinene, β-pinene, eucalyptol, menthone and menthol respectively. We have presented an initial set of easy-to-measure benchmarking values for assessing the performance of TD-GC-MS systems for the analysis of VOCs in breath. These values will be updated when more groups provide additional data.</p
The Single-Phase ProtoDUNE Technical Design Report
ProtoDUNE-SP is the single-phase DUNE Far Detector prototype that is under construction and will be operated at the CERN Neutrino Platform (NP) starting in 2018. ProtoDUNE-SP, a crucial part of the DUNE effort towards the construction of the first DUNE 10-kt fiducial mass far detector module (17 kt total LAr mass), is a significant experiment in its own right. With a total liquid argon (LAr) mass of 0.77 kt, it represents the largest monolithic single-phase LArTPC detector to be built to date. It's technical design is given in this report