[Rare complication of a dog bite: Capnocytophaga species bacteremia followed by an hemolytic uremic syndrome]. / Cas clinique. Complication méconnue des morsures canines : syndrome hémolytique et urémique suite à une bactériémie à Capnocytophaga Canimorsus.

Dog bites are a frequent reason for medical consultation. These can be responsible for severe infectious complications. Bacteria of the genus Capnocytophaga species are Gram-negative bacilli commonly found in the oral cavity of certain animals such as dogs and cats. Following a dog bite or wound contamination with animal spit, these bacteria can cause local (cellulitis), systemic and invasive manifestations (bacteremia, endocarditis, meningitis) or lead to rare and dreadful complications such as thrombotic microangiopathies. The identification of Capnocytophaga is slow due to their specific characteristics and their culture conditions. The treatment of Capnocytophaga species infections is based on antibiotic therapy with amoxicillin - clavulanic acid as the first choice. Although different types of Capnocytophaga have been described, C. Canimorsus appears to be associated with a higher rate of atypical complications. Here is the description of an immunocompetent patient who presented with C. Canimorsus bacteremia complicated by hemolytic uremic syndrome following a dog bite.

Les morsures de chien représentent un motif fréquent de consultation. Celles-ci peuvent entraîner des complications infectieuses graves. Les bactéries du genre Capnocytophaga species sont des bacilles Gram négatif fréquemment retrouvés dans la cavité buccale de certains animaux comme les chiens et les chats. à la suite d'une morsure canine ou d'une contamination de plaie par de la salive animale, ces bactéries peuvent provoquer des manifestations locales (cellulite), systémiques et invasives (bactériémie, endocardite, méningite) ou entraîner des complications rares et redoutables comme les microangiopathies thrombotiques. L'identification des Capnocytophaga est lente de par leurs caractéristiques propres et leurs conditions de mise en culture. Le traitement des infections à Capnocytophaga species repose sur une antibiothérapie par amoxicilline-acide clavulanique en première intention. Bien que différents types de Capnocytophaga aient été décrits, C. Canimorsus semble associé à un taux plus élevé de complications atypiques. Nous décrivons ici le cas d'une patiente immunocompétente ayant présenté une bactériémie à C. Canimorsus compliquée d'un syndrome hémolytique et urémique dans les suites d'une morsure de chien.

Revealing Hidden Orbital Pseudospin Texture with Time-Reversal Dichroism in Photoelectron Angular Distributions.

We performed angle-resolved photoemission spectroscopy (ARPES) of bulk 2H-WSe_{2} for different crystal orientations linked to each other by time-reversal symmetry. We introduce a new observable called time-reversal dichroism in photoelectron angular distributions (TRDAD), which quantifies the modulation of the photoemission intensity upon effective time-reversal operation. We demonstrate that the hidden orbital pseudospin texture leaves its imprint on TRDAD, due to multiple orbital interference effects in photoemission. Our experimental results are in quantitative agreement with both the tight-binding model and state-of-the-art fully relativistic calculations performed using the one-step model of photoemission. While spin-resolved ARPES probes the spin component of entangled spin-orbital texture in multiorbital systems, we unambiguously demonstrate that TRDAD reveals its orbital pseudospin texture counterpart.

Hydroureteronephrosis and fetal mummification secondary to uterine torsion in a Merino ewe.

A 6 year old pluriparous Merino ewe was presented for investigation of a large intra-abdominal mass. Post-mortem examination revealed a 360° clockwise uterine torsion was present with a mummifying fetus. The torsion involved the left ureter resulting in a severe hydroureteronephrosis. Uterine torsion is uncommon in the ewe, occurring in less than 0.1% of pregnancies in one report (Mahmoud et al. Livest Res Rural Dev 2018;30), but cases are likely to be undiagnosed, particularly under the extensive management conditions typical of Australia. The chronicity of the condition in this ewe would support this statement. To the authors' knowledge this is the first reported case of hydroureteronephrosis secondary to uterine torsion in any species.

Usefulness of pathological examinations of the central nervous system for monitoring and controlling perinatal lamb mortality.

Correct diagnosis of cause of death is necessary to suggest the most effective management interventions to reduce perinatal lamb mortality. Haemorrhage on the surface of the brain has been used as a field diagnostic tool to allocate lambs to a cause of death category, but the usefulness of this method was unclear. This study aimed to evaluate whether gross pathology was related to neuronal death and whether haemorrhage of the central nervous system (CNS) was distinct between differing causes of death, enabling indicators to be used in field diagnoses. Lambs dying from natural causes (n = 64) and from euthanasia (n = 7) underwent postmortem examination, then the brain and spinal cord were extracted and examined histologically. Histological changes consistent with neuronal death were not detected in any lamb. Haemorrhage of the meninges and/or parenchyma of the CNS occurred in all lambs. The age of the haemorrhage indicated that it occurred near the time of death in most lambs. Dilation of blood vessels varied in severity but appeared to be unrelated to causal diagnosis, severity of subcutaneous oedema, breathing or milk status. Moderate or severe dilation of blood vessels and haemorrhage of the CNS did not occur in all lambs with alternative clear indicators of dystocia and occurred in all death classifications, so it could not be used as diagnostic indicators for classification of cause of death. Dilation and haemorrhage were unrelated to neuronal damage and may have been artefactual. In conclusion, haemorrhage of the CNS was not indicative of neuronal damage and could not be used to distinguish between lambs with clear indicators of differing causes of death, so it is not recommended as a field diagnostic tool.

Neuronal tuning: Selective targeting of neuronal populations via manipulation of pulse width and directionality.

INTRODUCTION: Motor evoked potentials (MEP) in response to anteroposterior transcranial (AP) magnetic stimulation (TMS) are sensitive to the TMS pulse shape. We are now able to isolate distinct pulse properties, such as pulse width and directionality and evaluate them individually. Different pulse shapes induce different effects, likely by stimulating different populations of neurons. This implies that not all neurons respond in the same manner to stimulation, possibly, because individual segments of neurons differ in their membrane properties. OBJECTIVES: To investigate the effect of different pulse widths and directionalities of TMS on MEP latencies, motor thresholds and plastic aftereffects of rTMS. METHODS: Using a controllable pulse stimulator TMS (cTMS), we stimulated fifteen subjects with quasi-unidirectional TMS pulses of different pulse durations (40 µs, 80 µs and 120 µs) and determined thresholds and MEP AP latencies. We then compared the effects of 80 µs quasi-unidirectional pulses to those of 80 µs pulses with different pulse directionality characteristics (0.6 and 1.0 M ratios). We applied 900 pulses of the selected pulse shapes at 1 Hz. RESULTS: The aftereffects of 1 Hz rTMS depended on pulse shape and duration. 40 and 80 µs wide unidirectional pulses induced inhibition, 120 µs wide pulses caused excitation. Bidirectional pulses induced inhibition during the stimulation but had facilitatory aftereffects. Narrower pulse shapes caused longer latencies and higher resting motor thresholds (RMT) as compared to wider pulse shapes. CONCLUSIONS: We can tune the aftereffects of rTMS by manipulating pulse width and directionality; this may be due to the different membrane properties of the various neuronal segments such as dendrites. SIGNIFICANCE: To date, rTMS frequency has been the main determinant of the plastic aftereffects. However, we showed that pulse width also plays a major role, probably by recruiting novel neuronal targets.

The HLA-DQ2 genotype selects for early intestinal microbiota composition in infants at high risk of developing coeliac disease.

OBJECTIVE: Intestinal dysbiosis has been associated with coeliac disease (CD), but whether the alterations are cause or consequence of the disease is unknown. This study investigated whether the human leukocyte antigen (HLA)-DQ2 genotype is an independent factor influencing the early gut microbiota composition of healthy infants at family risk of CD. DESIGN: As part of a larger prospective study, a subset (n=22) of exclusively breastfed and vaginally delivered infants with either high genetic risk (HLA-DQ2 carriers) or low genetic risk (non-HLA-DQ2/8 carriers) of developing CD were selected from a cohort of healthy infants with at least one first-degree relative with CD. Infant faecal microbiota was analysed by 16S rRNA gene pyrosequencing and real time quantitative PCR. RESULTS: Infants with a high genetic risk had significantly higher proportions of Firmicutes and Proteobacteria and lower proportions of Actinobacteria compared with low-risk infants. At genus level, high-risk infants had significantly less Bifidobacterium and unclassified Bifidobacteriaceae proportions and more Corynebacterium, Gemella, Clostridium sensu stricto, unclassified Clostridiaceae, unclassified Enterobacteriaceae and Raoultella proportions. Quantitative real time PCR also revealed lower numbers of Bifidobacterium species in infants with high genetic risk than in those with low genetic risk. In high-risk infants negative correlations were identified between Bifidobacterium species and several genera of Proteobacteria (Escherichia/Shigella) and Firmicutes (Clostridium). CONCLUSIONS: The genotype of infants at family risk of developing CD, carrying the HLA-DQ2 haplotypes, influences the early gut microbiota composition. This finding suggests that a specific disease-biased host genotype may also select for the first gut colonisers and could contribute to determining disease risk.

Reduced intracortical inhibition and facilitation in the primary motor tongue representation of adults who stutter.

OBJECTIVE: We aimed at detecting neurophysiological changes, in the primary motor tongue representation in adults with persistent stuttering. METHODS: Using transcranial magnetic stimulation in 12 patients and 14 controls, we examined motor threshold, motor-evoked potential (MEP) input-output curve, short-term intracortical inhibition (SICI) and intracortical facilitation (ICF), based on eight trials per conditioning-test interval. RESULTS: In controls inhibition of the MEP-amplitude at short inter-stimulus intervals (ISI) and facilitation of the MEP-amplitude at long ISIs was evident. Patients showed an inhibition at ISI 3 ms and weaker non-significant inhibition at ISI 2 ms; this delay of inhibitory activity was especially prominent in the right hemisphere. Facilitation was reduced at ISI 10 and 15 ms in patients. Furthermore, MEP input-output curve was steeper in patients. Motor thresholds did not differ between groups. CONCLUSIONS: In persistent stuttering intracortical excitability of the primary motor tongue representation is altered with a deviant time course for inhibitory activity in the right hemisphere and reduced paired-pulse facilitation. SIGNIFICANCE: These results specify changes in intracortical networks possibly mediated by altered GABAergic regulations in persistent stuttering. Thus, a better understanding of pathomechanisms and a potential role in understanding pharmacological treatment responses emerge by using transcranial magnetic stimulation.

The actions of barium and strontium on exocytosis and endocytosis in the synaptic terminal of goldfish bipolar cells.

1. We investigated the properties of Ca2+-sensitive steps in the cycling of synaptic vesicles by comparing the actions of Ca2+, Ba2+ and Sr2+ in the synaptic terminal of depolarizing bipolar cells isolated from the retina of goldfish. FM1-43 fluorescence and capacitance measurements demonstrated that exocytosis, endocytosis and vesicle mobilization were maintained when external Ca2+ was replaced by either Ba2+ or Sr2+. 2. The rapidly releasable pool of vesicles (RRP) was equivalent to 1.5 % of the membrane surface area when measured in the presence of 2.5 mM Ca2+, but only 0.4 % in 2.5 mM Sr2+. The relative sizes of the RRP in Ca2+, Sr2+ and Ba2+ were 1.0, 0.28 and 0.1, respectively. We conclude that a smaller proportion of docked vesicles are available for fast exocytosis triggered by the influx of Sr2+ or Ba2+ compared to Ca2+. 3. The slow phase of exocytosis was not altered when Ca2+ was replaced by Ba2+, but it was accelerated 1.6-fold in Sr2+. The peak concentrations of Ca2+, Sr2+ and Ba2+ (measured using Mag-fura-5) were approximately 4, approximately 14 and approximately 60 microM, respectively. The order of efficiency for the stimulation of slow exocytosis was Ca2+ approximately Sr2+ > Ba2+. 4. Exocytosis was prolonged after the influx of Sr2+ and Ba2+. Sr2+ was cleared from the synaptic terminal with the same time constant as Ca2+ (1.3 s), but Ba2+ was cleared 10-100 times more slowly. Although Ba(2+) stimulates the slow release of a large number of vesicles, it did so less efficiently than Ca2+ or Sr2+. 5. The recovery of the membrane capacitance was equally rapid in Sr2+ and Ca2+, demonstrating that the fast mode of endocytosis could be triggered by either cation.

Description of Pseudaminobacter gen. nov. with two new species, Pseudaminobacter salicylatoxidans sp. nov. and Pseudaminobacter defluvii sp. nov.

An aerobic bacterium, strain BN12T, which degrades substituted naphthalenesulfonates and substituted salicylates was isolated from a 6-aminonaphthalene-2-sulfonate-degrading microbial consortium originating from the River Elbe, Germany. Chemotaxonomic investigations of quinones, polyamines and polar lipids allowed allocation of this strain to the alpha-subclass of the Proteobacteria and revealed similarity to species of the genera Aminobacter, Chelatobacter and Mesorhizobium. This was confirmed by typing with 16S rRNA-targeted oligonucleotide probes and 16S rDNA sequencing and phylogenetic analysis, indicating that BN12T clusters most closely with a strain 'Thiobacillus' THI 051T and with the above genera but comprising a separate branch. DNA-DNA hybridizations demonstrated that strain BN12T is different from all species of Aminobacter currently described and recognized. The fatty acid patterns, substrate utilization profile and biochemical characteristics displayed no obvious similarity to the characteristics of Aminobacter and Chelatobacter species. 'Thiobacillus' THI 051T, however, revealed phenotypic similarities to BN12T. Furthermore, 16S rRNA sequences of Chelatobacter heintzii showed a high similarity to the 16S rRNA sequences of all currently recognized Aminobacter species. On the basis of these and previously published results, the new genus Pseudaminobacter is proposed, harbouring the two new species Pseudaminobacter salicylatoxidans sp. nov. and Pseudaminobacter defluvii sp. nov. The type strains are BN12T (= DSM 6986T) and THI 051T (= IFO 14570T), respectively.

Detection of sphingomonads and in situ identification in activated sludge using 16S rRNA-targeted oligonucleotide probes.

The increasing significance of members of the genus Sphingomonas in biotechnological applications has led to an increased interest in the diversity, abundance and ecophysiological potential of this group of Gram-negative bacteria. This general focus provides a challenge to improve means for identification of sphingomonads; eg molecular genetic methods for rapid and specific detection could facilitate screening of new isolates. Here, fluorescently labeled oligonucleotide probes targeted against 16S rRNA were used to typify strains previously assigned to the genus. All 46 sphingomonads tested including type strains of 21 Sphingomonasspecies could be detected with a probe originally designed for the genus and all but one with a probe designed for the alpha-4 subgroup of the Proteobacteria. The two probes are suitable for direct detection of sphingomonads in pure and mixed cultures as well as in environmental samples of unknown composition. The probes were used to identify sphingomonads in situ in activated sludge samples. Sphingomonads were rather abundant accounting for about 5-10% of the total cells in municipal sludges. Distinct patterns in aggregation of the cells suggest that these organisms could be involved in the formation process of sludge flocs.

[Detection of airborne cultivatable microorganisms from compost sites--emissions and imissions]. / Erfassung von luftgetragenen kultivierbaren Mikroorganismen aus Kompostierungsanlagen--Emission und Immission.

The statement presented here gives an overview and assessment of the procedures and concepts currently used for the collection and determination of airborne, culturable microorganisms at sources of emission within composting plants and in their near vicinity. The paper focuses on "classical" methods, which involve cultivation as an intermediate step for the determination of viable, airborne microorganisms. The theoretical and practical requirements on such methods are discussed. Results and experiences from recent investigations are described.

[Recent methods for the detection of airborne microorganisms and source identification]. / Neuere Methoden zum Nachweis luftgetragener Mikroorganismen und zur Quellenidentifikation.

The detection of airborne microorganisms including selected cell constituents (e.g. allergens or endotoxins) depends on suitable methods and instruments for their collection. Furthermore, microbiological methods are necessary for their quantification and qualification. In the past these methods were largely based on the classical cultivation dependent approach. Modern molecular methods, e.g. direct staining procedures, hybridization assays with nucleic acids including the PCR-technology or immunological assays are promising new tools for a more sophisticated detection of bioaerosols. They allow a better detection rate, a more precise identification of certain members of the aerosol including cell constituents. With respect to speed and lower costs they are an important alternative to established detection methods.

[Measuring the spread of airborne microorganisms in the area of composting sites]. / Messungen zur Ausbreitung von luftgetragenen Mikroorganismen im Umfeld von Kompostierungsanlagen.

Emission concentrations of culturable microorganisms were determined in the vicinity of three open or partly encapsulated composting facilities. Sampling was performed during so-called worst case situations which should promote aerial transport of emissions. Suitability of thermophilic organisms to detect an emitting influence of the plant was confirmed. Generally, concentrations decreased significantly with increasing distances from the plant at all three locations. At one plant 10(6) CFU m-3 thermophilic actinomycetes were found in a distance of 200 m. Partly increased concentrations could be determined even in distances above 500 m. Concentrations could vary within one hour to more than ten times.

Two-electrode voltage clamp of Xenopus oocytes under high hydrostatic pressure.

Functional assays of cloned ion channels and other transport systems under various hydrostatic pressures provide information on the apparent changes in protein volume occurring during conformational rearrangements. Thus, they are valuable tools in the detailed study of the molecular steps underlying the functioning of such proteins. Here we present details of a set-up which can be used for two-electrode voltage-clamp experiments on Xenopus oocytes, commonly used for heterologous protein expression, at hydrostatic (oil) pressures as high as 60 MPa (approximately 600 atm.). The advantages of this set-up over pneumatic systems include the minimization of compression/decompression-induced temperature changes, and an increased safety of handling due to the small volume (< 10 ml) of compression medium (oil) required. The performance of the system is illustrated using experimental data on the effects of high pressure on currents recorded from oocytes expressing a Shaker potassium channel mutant. This set-up is suitable for the investigation of all electrically measurable transport systems expressed in Xenopus oocytes.

Population analysis in a denitrifying sand filter: conventional and in situ identification of Paracoccus spp. in methanol-fed biofilms.

The microbial community of a denitrifying sand filter in a municipal wastewater treatment plant was examined by conventional and molecular techniques to identify the bacteria actively involved in the removal of nitrate. In this system, denitrification is carried out as the last step of water treatment by biofilms growing on quartz grains with methanol as a supplemented carbon source. The biofilms are quite irregular, having a median thickness of 13 to 20 microns. Fatty acid analysis of 56 denitrifying isolates indicated the occurrence of Paracoccus spp. in the sand filter. 16S rRNA-targeted probes were designed for this genus and the species cluster Paracoccus denitrificans-Paracoccus versutus and tested for specificity by whole-cell hybridization. Stringency requirements for the probes were adjusted by use of a formamide concentration gradient to achieve complete discrimination of even highly similar target sequences. Whole-cell hybridization confirmed that members of the genus Paracoccus were abundant among the isolates. Twenty-seven of the 56 isolates hybridized with the genus-specific probes. In situ hybridization identified dense aggregates of paracocci in detached biofilms. Probes complementary to the type strains of P. denitrificans and P. versutus did not hybridize to cells in the biofilms, suggesting the presence of a new Paracoccus species in the sand filter. Analysis using confocal laser scanning microscopy detected spherical aggregates of morphologically identical cells exhibiting a uniform fluorescence. Cell quantification was performed after thorough disruption of the biofilms and filtration onto polycarbonate filters. An average of 3.5% of total cell counts corresponded to a Paracoccus sp., whereas in a parallel sand filter with no supplemented methanol, and no measurable denitrification, only very few paracocci (0.07% of cells stained with 4',6-diamidino-2-phenylindole) could be detected. Hyphomicrobium spp. constituted approximately 2% of all cells in the denitrifying unit and could not be detected in the regular sand filter. This clear link between in situ abundance and denitrification suggests an active participation of paracocci and hyphomicrobia in the process. Possible selective advantages favoring the paracocci in this habitat are discussed.