Search

Background Acinetobacter baumannii is a common cause of healthcare-associated infections. Carbapenem-resistant (CR) A baumannii is a significant threat globally. We used a large reference laboratory database to study the epidemiology of A baumannii in children in the United States. Methods Antimicrobial susceptibility data from The Surveillance Network were used to phenotypically identify antibiotic resistance in A baumannii isolates in children 1–17 years of age between January 1999 and July 2012. Logistic regression analysis was used to calculate trends in the prevalence of antibiotic resistance in A baumannii. Isolates from infants (<1 year old) were excluded. Results The crude proportion of cephalosporin-resistant (CephR) A baumannii increased from 13.2% in 1999 to 23.4% in 2012 with a peak of 32.5% in 2008, and the proportion of CR A baumannii increased from 0.6% in 1999 to 6.1% in 2012 with a peak of 12.7% in 2008. From 1999 to 2012, the proportion of CephR and CR A baumannii increased each year by 3% and 8%, respectively (CephR odds ratio [OR] = 1.03, 95% confidence interval [CI], 1.01–1.04; CR OR = 1.08, 95% CI, 1.05–1.12); however, after 2008, a significant decrease in trend was observed (CephR OR = 0.78, 95% CI, 0.71–0.87; CR OR = 0.73, 95% CI, 0.62–0.86), but resistance remained higher than baseline (1999). Conclusions Overall, between 1999 and 2012, CephR and CR A baumannii isolates increased in children; however, a decreasing trend was observed after 2008.There is a need for ongoing surveillance of A baumannii infections and continued assessment of effective prevention strategies in vulnerable populations. [ABSTRACT FROM AUTHOR]

Large tertiary care hospitals (TCHs) are thought to have higher antimicrobial resistance (AMR) rates when compared to small community hospitals (SCHs) as they provide care to patients with higher disease severity. However, we found no systematic differences in AMR rates between TCHs and SCHs in the United States. [ABSTRACT FROM AUTHOR]

Motivation: The arbor morphologies of brain microglia are important indicators of cell activation. This article fills the need for accurate, robust, adaptive and scalable methods for reconstructing 3-D microglial arbors and quantitatively mapping microglia activation states over extended brain tissue regions. Results: Thick rat brain sections (100-300 μm) were multiplex immunolabeled for IBA1 and Hoechst, and imaged by step-and-image confocal microscopy with automated 3-D image mosaicing, producing seamless images of extended brain regions (e.g. 5903×9874×229 voxels). An over-complete dictionary-based model was learned for the image-specific local structure of microglial processes. The microglial arbors were reconstructed seamlessly using an automated and scalable algorithm that exploits microglia-specific constraints. This method detected 80.1 and 92.8% more centered arbor points, and 53.5 and 55.5% fewer spurious points than existing vesselness and LoG-based methods, respectively, and the traces were 13.1 and 15.5% more accurate based on the DIADEM metric. The arbor morphologies were quantified using Scorcioni's L-measure. Coifman's harmonic co-clustering revealed four morphologically distinct classes that concord with known microglia activation patterns. This enabled us to map spatial distributions of microglial activation and cell abundances. [ABSTRACT FROM AUTHOR]

The effect of long-term heavy-metal contamination on soil microbial and meiofaunal communities was assessed with a view to determining whether analysis of these communities could be used for ecological assessment of contaminated sites. Thirty soil cores were taken from an industrial site formerly used for the burning of waste from an explosives factory. The predominant contaminants in the soil were a range of heavy metals, including lead, copper and zinc. The numbers of culturable bacteria (especially those grown on Pseudomonas selective media) and the microbial community response to a suite of 95 carbon sources were suppressed in samples with high heavy-metal contamination. This corresponded to a reduction in the density and evenness of the nematode communities in the samples with high metal concentrations. Conversely the bacterial counts and responses to the 95 carbon sources were greater at sites with higher and more diverse populations of nematodes. However, epifluorescence counts of bacteria and the profiles of extracted fatty acids were not consistently altered by the heavy-metal contamination. These results suggest that culturable bacteria are effective indicators of pollution in soil, and reflect the perturbations seen in other components of the soil biota. Furthermore, this is the first study to show that both meiofaunal communities and microbial communities give similar indications of the ecological impact of heavy-metal contamination in soil. [Copyright &y& Elsevier]