[Prevalence of multiresistant gram-negative bacteria in inhabitants of long-term care facilities in 2019 in Thuringia]. / Prävalenz von multiresistenten gramnegativen Erregern bei Bewohnern von stationären Pflegeeinrichtungen 2019 in Thüringen.

BACKGROUND: Multidrug-resistant gram-negative bacteria (MDRGN) pose an emerging threat in German hospitals and in the outpatient sector. However, only few studies have investigated the prevalence of MDRGN in nonhospital settings and the associated risk factors for colonization. OBJECTIVE: In our study we determined the prevalence of MDRGN in inhabitants of long-term care facilities (LTCFs) and associated risk factors for colonization in the region Weimar, Weimarer Land, and Jena. METHODS: Between May and August 2019, deep rectal swabs were taken from 307 inhabitants of 13 facilities and examined microbiologically for the presence of MDRGN. Furthermore, using a standardized questionnaire, the characteristics of the inhabitants were collected and their association with the likelihood for colonization with MDRGN was analyzed. RESULTS: MDRGN were found in 59 swabs, predominantly Escherichia coli (95%). The weighted prevalence of extended spectrum beta-lactamase-producing bacteria was 19.1% and for MDRGN with additional resistances to fluoroquinolones was 12.3%. Resistances to carbapenems or carbapenemases were not found. Multivariable as well as univariable analysis recognized the presence of chronic wounds to be a potential risk factor (OR: 2,66 [95 %-CI: 1,54-4,60]). Additionally, the univariable analysis detected the necessity of a wheelchair and the accommodation in double rooms as risk factors. DISCUSSION: The prevalence of MDRGN found in our study is similar to findings of previous German studies. The result shows the importance of strict compliance with basic hygiene guidelines for all inhabitants of LTCFs for the prevention of transmission of MDRGN.

Pro-apoptotic function of GABA-related transcripts following stroke.

Following cerebral injuries such as stroke, a structural and functional reorganization of the impaired tissue occurs, which is often accompanied by a re-expression of developmental genes. During brain development, embryonic splice variants of the GABA-synthesizing GAD67 gene (collectively termed EGAD) participate in cell proliferation, migration, and neuronal differentiation. We thus hypothesized an involvement of EGAD in post-ischemic plasticity. EGAD transcripts were up-regulated at early reperfusion times in the injured area following transient middle cerebral artery occlusion (with a peak expression of 4.5-fold at 6h in C57BL/6 mice). Cell-specific analysis by a combination of radioactive in situ hybridization and immunolabeling revealed EGAD up-regulation in TUNEL-positive neurons. This unexpected cell death-associated expression of EGAD was confirmed in cell culture models of ischemia (combined oxygen-glucose deprivation) and apoptosis (staurosporine). Staurosporine-mediated cell death led to cleaved Caspase-3 activation, a key regulator of apoptosis following stroke. Blocking of staurosporine-associated EGAD expression via antisense RNA treatment reduced cleaved Caspase-3 activation by ~30%. In addition to the involvement of EGAD in proliferative processes during brain development, we found here that EGAD participates in cell death under pathophysiological conditions in the adult brain. Re-expression of EGAD in neurons following stroke may play a role in aberrant cell cycle activation, consequently being pro-apoptotic. Our observation of a new GABA related pro-apoptotic mechanism and its successful modification might be of significant clinical relevance.

Identification of ischemic regions in a rat model of stroke.

BACKGROUND: Investigations following stroke first of all require information about the spatio-temporal dimension of the ischemic core as well as of perilesional and remote affected tissue. Here we systematically evaluated regions differently impaired by focal ischemia. METHODOLOGY/PRINCIPAL FINDINGS: Wistar rats underwent a transient 30 or 120 min suture-occlusion of the middle cerebral artery (MCAO) followed by various reperfusion times (2 h, 1 d, 7 d, 30 d) or a permanent MCAO (1 d survival). Brains were characterized by TTC, thionine, and immunohistochemistry using MAP2, HSP72, and HSP27. TTC staining reliably identifies the infarct core at 1 d of reperfusion after 30 min MCAO and at all investigated times following 120 min and permanent MCAO. Nissl histology denotes the infarct core from 2 h up to 30 d after transient as well as permanent MCAO. Absent and attenuated MAP2 staining clearly identifies the infarct core and perilesional affected regions at all investigated times, respectively. HSP72 denotes perilesional areas in a limited post-ischemic time (1 d). HSP27 detects perilesional and remote impaired tissue from post-ischemic day 1 on. Furthermore a simultaneous expression of HSP72 and HSP27 in perilesional neurons was revealed. CONCLUSIONS/SIGNIFICANCE: TTC and Nissl staining can be applied to designate the infarct core. MAP2, HSP72, and HSP27 are excellent markers not only to identify perilesional and remote areas but also to discriminate affected neuronal and glial populations. Moreover markers vary in their confinement to different reperfusion times. The extent and consistency of infarcts increase with prolonged occlusion of the MCA. Therefore interindividual infarct dimension should be precisely assessed by the combined use of different markers as described in this study.

Adult and embryonic GAD transcripts are spatiotemporally regulated during postnatal development in the rat brain.

BACKGROUND: GABA (gamma-aminobutyric acid), the main inhibitory neurotransmitter in the brain, is synthesized by glutamic acid decarboxylase (GAD). GAD exists in two adult isoforms, GAD65 and GAD67. During embryonic brain development at least two additional transcripts exist, I-80 and I-86, which are distinguished by insertions of 80 or 86 bp into GAD67 mRNA, respectively. Though it was described that embryonic GAD67 transcripts are not detectable during adulthood there are evidences suggesting re-expression under certain pathological conditions in the adult brain. In the present study we systematically analyzed for the first time the spatiotemporal distribution of different GADs with emphasis on embryonic GAD67 mRNAs in the postnatal brain using highly sensitive methods. METHODOLOGY/PRINCIPAL FINDINGS: QPCR was used to precisely investigate the postnatal expression level of GAD related mRNAs in cortex, hippocampus, cerebellum, and olfactory bulb of rats from P1 throughout adulthood. Within the first three postnatal weeks the expression of both GAD65 and GAD67 mRNAs reached adult levels in hippocampus, cortex, and cerebellum. The olfactory bulb showed by far the highest expression of GAD65 as well as GAD67 transcripts. Embryonic GAD67 splice variants were still detectable at birth. They continuously declined to barely detectable levels during postnatal development in all investigated regions with exception of a comparatively high expression in the olfactory bulb. Radioactive in situ hybridizations confirmed the occurrence of embryonic GAD67 transcripts in the olfactory bulb and furthermore detected their localization mainly in the subventricular zone and the rostral migratory stream. CONCLUSIONS/SIGNIFICANCE: Embryonic GAD67 transcripts can hardly be detected in the adult brain, except for specific regions associated with neurogenesis and high synaptic plasticity. Therefore a functional role in processes like proliferation, migration or synaptogenesis is suggested.