487 research outputs found
Outbreak of Burkholderia cepacia complex infections associated with contaminated octenidine mouthwash solution, Germany, August to September 2018
Three German patients developed nosocomial pneumonia after cardiac surgery and had Burkholderia
cepacia complex detected in respiratory specimens.
Two patients died of septic multi-organ failure. Wholegenome sequencing detected genetically identical B.
cepacia complex strains in patient samples, from a
batch of octenidine mouthwash solution, which had
been used for nursing care, as well as in samples
obtained from the manufacturer during production.
Contamination of medical products during manufacturing may lead to international outbreaks
Molecular epidemiology and antimicrobial resistance of Clostridioides difficile detected in chicken, soil and human samples from Zimbabwe
Background: Clostridioides difficile is the major cause of infectious nosocomial diarrhoea in industrialized nations. Data on the occurrence of C. difficile in Africa, ribotype (RT) distribution, antimicrobial susceptibility patterns and potential zoonotic transmission are scarce. Methods: 80 Zimbabwean C. difficile isolates from different sources (chicken [n = 30], soil [n = 21] and humans [n = 29]) were investigated using ribotyping, toxin gene detection, resistance testing, multiple-locus variable-number tandem repeat analysis (MLVA), and whole genome sequencing (WGS). Results: Among chicken isolates, the most common RTs were RT103 (6/30), RT025 (5/30) and RT070 (4/30). Within soil samples, RT025 and RT056 were most common (3/21 each). In contrast, the non-toxigenic RT084 was most frequently found in human isolates (4/29). Toxin genes were detected in only 19/29 human isolates. Susceptibility testing showed no resistance against metronidazole and vancomycin, and resistance against macrolides and rifampicin was scarce (3/80 and 2/80, respectively); however, 26/80 isolates showed moxifloxacin resistance. MLVA and WGS of strains with identical RTs stemming from different sources revealed clustering of RT025 and RT084 isolates from human und non-human samples. Conclusion: No "hypervirulent” strains were found. The detected clusters between human, chicken and soil isolates indicate ongoing transmission between humans and environmental sources and might point towards a zoonotic potential
Antigen-Specific vs. Neutralizing Antibodies Against Conditioned Media of Patients With Clostridioides difficile Infection: A Prospective Exploratory Study
The immunological response against Clostridioides difficile (C. difficile) is crucial for an
improved understanding of disease mechanisms and the development of novel therapeutic
strategies. From April 2014 to February 2015, adult patients with C. difficile infection (CDI)
were recruited, and the clinical course and treatment response were carefully monitored.
On day 1, 3, and 6 after diagnosis, patient plasma samples were screened for anti-GDH
(glutamate dehydrogenase), anti-TcdA, anti-TcdB, and anti-CWP84 (cell-wall protein 84)
antibodies by ELISA. Additionally, neutralization assays of toxins from conditioned media
of clinical isolates (RT010, RT014, and RT027) were performed. Most patients with CDI
(n=46) had antibodies against GDH (85%) and CWP84 (61%), but only few had antibodies
against TcdA (11%) and TcdB (28%). We found patients with neutralizing antibodies against
C. difficile toxins (conditioned media) produced by RT027 (26%). A subgroup of these
samples could neutralize both toxins from RT027 and RT014 [11%, (5/46)]; however, no
single sample neutralized only RT014. Overall, neutralizing antibody titers were low (≤1:16).
In a one week follow-up of acute infection, we never observed an early booster effect
with seroconversion or antibody increases, irrespective of disease severity. No correlation
was found between the presence of antigen-specific (ELISA) or neutralizing antibodies
and the clinical course of disease. Anti-TcdB but not anti-TcdA antibodies correlated with
the occurrence of neutralizing antibodies. In conclusion, natural antibody titers against C.
difficile toxins were absent or low and were not associated with disease severity. The
correlation between the anti-TcdB with toxin neutralization confirms the importance of
TcdB for virulence of CDI. Alternative sensitization strategies, e.g., through vaccine
development, are required to overcome the regular low-titer antibody production following
natural intestinal C. difficile exposure
Optical Properties of Radio-selected Narrow Line Seyfert 1 Galaxies
We present results from the analysis of the optical spectra of 47
radio-selected narrow-line Seyfert 1 galaxies (NLS1s). These objects are a
subset of the First Bright Quasar Survey (FBQS) and were initially detected at
20 cm (flux density limit ~1 mJy) in the VLA FIRST Survey. We run Spearman rank
correlation tests on several sets of parameters and conclude that, except for
their radio properties, radio-selected NLS1 galaxies do not exhibit significant
differences from traditional NLS1 galaxies. Our results are also in agreement
with previous studies suggesting that NLS1 galaxies have small black hole
masses that are accreting very close to the Eddington rate. We have found 16
new radio-loud NLS1 galaxies, which increases the number of known radio-loud
NLS1 galaxies by a factor of ~5.Comment: 18 pages, 20 figures, Accepted for publication in Ap
Application and clinical impact of the RESIST-4 O.K.N.V. rapid diagnostic test for carbapenemase detection in blood cultures and clinical samples
Invasive infections caused by carbapenemase-producing bacteria are associated with excess mortality. We applied a rapid diagnostic test (RDT) on clinical samples with an elevated likelihood of carbapenemase-producing bacteria and documented its impact on antibiotic treatment decisions. Among 38 patients, twelve tested positive for infections caused by carbapenemase-producing bacteria (31.6%), mainly in blood cultures. KPC (n = 10) was more frequent than OXA-48 (n = 2). RDT-based carbapenemase detection led to a treatment modification to ceftazidime/avibactam-containing regimens in all patients before detailed antibiotic testing results became available. Eleven patients (92%) survived the acute infection, whereas one patient with a ceftazidime/avibactam- and colistin-resistant OXA-48-positive isolate died
The Interaction between the ISM and Star Formation in the Dwarf Starburst Galaxy NGC 4214
We present the first interferometric study of the molecular gas in the
metal-poor dwarf starburst galaxy NGC 4214. Our map of the 12CO(1-0) emission,
obtained at the OVRO millimeter array, reveals an unexpected structural wealth.
We detected three regions of molecular emission in the north-west (NW),
south-east (SE) and centre of NGC 4214 which are in very different and distinct
evolutionary stages (total molecular mass: 5.1 x 10^6 M_sun). These differences
are apparent most dramatically when the CO morphologies are compared to optical
ground based and HST imaging: massive star formation has not started yet in the
NW region; the well-known starburst in the centre is the most evolved and star
formation in the SE complex started more recently. We derive a star formation
efficiency of 8% for the SE complex. Using high--resolution VLA observations of
neutral hydrogen HI and our CO data we generated a total gas column density map
for NGC 4214 (HI + H_2). No clear correlation is seen between the peaks of HI,
CO and the sites of ongoing star formation. This emphasizes the irregular
nature of dwarf galaxies. The HI and CO velocities agree well, so do the
H-alpha velocities. In total, we cataloged 14 molecular clumps in NGC 4214. Our
results from a virial mass analysis are compatible with a Galactic CO-to-H_2
conversion factor for NGC 4214 (lower than what is usually found in metal-poor
dwarf galaxies).Comment: accepted for publication in the AJ (February 2001), full ps file at:
ftp://ftp.astro.caltech.edu/users/fw/ngc4214/walter_prep.p
Discrimination between hypervirulent and non-hypervirulent ribotypes of Clostridioides difficile by MALDI-TOF mass spectrometry and machine learning
Hypervirulent ribotypes (HVRTs) of Clostridioides difcile such as ribotype (RT) 027 are epidemiologically important.
This study evaluated whether MALDI-TOF can distinguish between strains of HVRTs and non-HVRTs commonly found
in Europe. Obtained spectra of clinical C. difcile isolates (training set, 157 isolates) covering epidemiologically relevant
HVRTs and non-HVRTs found in Europe were used as an input for diferent machine learning (ML) models. Another 83
isolates were used as a validation set. Direct comparison of MALDI-TOF spectra obtained from HVRTs and non-HVRTs
did not allow to discriminate between these two groups, while using these spectra with certain ML models could diferentiate HVRTs from non-HVRTs with an accuracy >95% and allowed for a sub-clustering of three HVRT subgroups (RT027/
RT176, RT023, RT045/078/126/127). MALDI-TOF combined with ML represents a reliable tool for rapid identifcation of
major European HVRTs
A high velocity ionised outflow and XUV photosphere in the narrow emission line quasar PG1211+143
We report on the analysis of a ~60 ksec XMM observation of the bright, narrow
emission line quasar PG 1211+143. Absorption lines are seen in both EPIC and
RGS spectra corresponding to H- and He-like ions of Fe, S, Mg, Ne, O, N and C.
The observed line energies indicate an ionised outflow velocity of ~24000 km
s^-1. The highest energy lines require a column density of N_H ~ 5 x 10^23
cm^-2, at an ionisation parameter of log(xi) ~ 3.4. If the origin of this high
velocity outflow lies in matter being driven from the inner disc, then the flow
is likely to be optically thick within a radius ~130 Schwarzschild radii,
providing a natural explanation for the Big Blue Bump (and strong soft X-ray)
emission in PG 1211+143.Comment: Accepted by MNRAS; Table 1 correcte
The radio properties of a complete, X-ray selected sample of nearby, massive elliptical galaxies
We investigate the radio properties of a complete sample of nearby, massive,
X-ray bright elliptical and S0 galaxies. Our sample contains 18 galaxies with
ROSAT All-Sky Survey X-ray fluxes Fx_(0.1-2.4 keV) > 3 x 10^(-12) erg/s/cm^2,
within a distance of 100 Mpc. For these galaxies, we have complete (18/18) VLA
radio and Chandra X-ray coverage. Nuclear radio emission is detected from 17/18
of the galaxies. Ten of the galaxies exhibit extended radio emission; of these
ten, all but one also exhibit clear evidence of interaction of the radio source
with the surrounding, X-ray emitting gas. Among the seven galaxies with
unresolved radio sources, one has clear, and one has small, cavity-like
features in the Chandra X-ray images; a third has a disturbed X-ray morphology.
Using a radio luminosity limit equivalent to L_(1.4 Ghz) > 10^(23) W/Hz to
calculate the radio-loud fraction, we find that this misses the majority of the
radio detected galaxies in the sample. We determine integrated radio-to-X-ray
flux ratios for the galaxies, GRx, which are shown to span a large range
(factor of 100). We calculate the mass-weighted cooling times within 1 kpc, and
find hints for an anticorrelation with the radio luminosity. We also calculate
limits on k/f, where k is the ratio of the total particle energy to that of
relativistic electrons radiating in the range 10 MHz-10 GHz and f is the volume
filling factor of the plasma in the cavity. The k/f distribution is also broad,
reflecting previous results for larger galaxy clusters. Lowering the X-ray flux
limit, at the expense of less complete VLA and Chandra coverage, increases the
size of our sample to 42 galaxies. Nuclear radio activity is detected in at
least 34/42 of this extended sample.Comment: Accepted for publication in MNRAS, 19 pages, 11 Figures and 7 Table
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