Coding of shape and position in macaque lateral parietal area

The analysis of object shape is critical for both object recognition and grasping. Areas in the intraparietal sulcus of the rhesus monkey are important for the visuomotor transformations underlying actions directed toward objects. The lateral intraparietal (LIP) area has strong anatomical connections with the anterior intraparietal area, which is known to control the shaping of the hand during grasping, and LIP neurons can respond selectively to simple two-dimensional shapes. Here we investigate the shape representation in area LIP of awake rhesus monkeys. Specifically, we determined to what extent LIP neurons are tuned to shape dimensions known to be relevant for grasping and assessed the invariance of their shape preferences with regard to changes in stimulus size and position in the receptive field. Most LIP neurons proved to be significantly tuned to multiple shape dimensions. The population of LIP neurons that were tested showed barely significant size invariance. Position invariance was present in a minority of the neurons tested. Many LIP neurons displayed spurious shape selectivity arising from accidental interactions between the stimulus and the receptive field. We observed pronounced differences in the receptive field profiles determined by presenting two different shapes. Almost all LIP neurons showed spatially selective saccadic activity, but the receptive field for saccades did not always correspond to the receptive field as determined using shapes. Our results demonstrate that a subpopulation of LIP neurons encodes stimulus shape. Furthermore, the shape representation in the dorsal visual stream appears to differ radically from the known representation of shape in the ventral visual stream.status: publishe

Imported diseases in travellers presenting to the emergency department after a stay in a malaria-endemic country: a retrospective observational study.

We aimed to investigate the aetiology and outcomes of illnesses in patients presenting to an emergency department after travelling to a malaria-endemic country, in order to raise awareness of both tropical and cosmopolitan diseases.info:eu-repo/semantics/publishe

Considerations in evaluating equipment-free blood culture bottles: A short protocol for use in low-resource settings.

Use of equipment-free, "manual" blood cultures is still widespread in low-resource settings, as requirements for implementation of automated systems are often not met. Quality of manual blood culture bottles currently on the market, however, is usually unknown. An acceptable quality in terms of yield and speed of growth can be ensured by evaluating the bottles using simulated blood cultures. In these experiments, bottles from different systems are inoculated in parallel with blood and a known quantity of bacteria. Based on literature review and personal experiences, we propose a short and practical protocol for an efficient evaluation of manual blood culture bottles, aimed at research or reference laboratories in low-resource settings. Recommendations include: (1) practical equivalence of horse blood and human blood; (2) a diverse selection of 10 to 20 micro-organisms to be tested (both slow- and fast-growing reference organisms); (3) evaluation of both adult and pediatric bottle formulations and blood volumes; (4) a minimum sample size of 120 bottles per bottle type; (5) a formal assessment of usability. Different testing scenarios for increasing levels of reliability are provided, along with practical tools such as worksheets and surveys that can be used by laboratories wishing to evaluate manual blood culture bottles

Biphasic versus monophasic manual blood culture bottles for low-resource settings: an in-vitro study

Background: Manual blood culture bottles (BCBs) are frequently used in low-resource settings. There are few BCB performance evaluations, especially evaluations comparing them with automated systems. We evaluated two manual BCBs (Bi-State BCB and BacT/ALERT BCB) and compared their yield and time to growth detection with those of automated BacT/ALERT system. Methods: BCBs were spiked in triplicate with 177 clinical isolates representing pathogens common in low-resource settings (19 bacterial and one yeast species) in adult and paediatric volumes, resulting in 1056 spiked BCBs per BCB system. Growth in manual BCBs was evaluated daily by visually inspecting the broth, agar slant, and, for BacT/ALERT BCB, colour change of the growth indicator. The primary outcomes were BCB yield (proportion of spiked BCB showing growth) and time to detection (proportion of positive BCB with growth detected on day 1 of incubation). 95% CI for yield and growth on day 1 were calculated using bootstrap method for clustered data using. Secondary outcomes were time to colony for all BCBs (defined as number of days between incubation and colony growth sufficient to use for further testing) and difference between time to detection in broth and on agar slant for the Bi-State BCBs. Findings: Overall yield was 95·9% (95% CI 93·9–98·0) for Bi-State BCB and 95·5% (93·3–97·8) for manual BacT/ALERT, versus 96·1% (94·0–98·1) for the automated BacT/ALERT system (p=0·61). Day 1 growth was present in 920 (90·8%) of 1013 positive Bi-State BCB and 757 (75·0%) of 1009 positive manual BacT/ALERT BCB, versus 1008 (99·3%) of 1015 automated bottles. On day 2, detection rates were 100% for BI-State BCB, 97·7% for manual BacT/ALERT BCB, and 100% for automated bottles. For Bi-State BCB, growth mostly occurred simultaneously in broth and slant (81·7%). Sufficient colony growth on the slant to perform further tests was present in only 44·1% of biphasic bottles on day 2 and 59·0% on day 3. Interpretation: The yield of manual BCB was comparable with the automated system, suggesting that manual blood culture systems are an acceptable alternative to automated systems in low-resource settings. Bi-State BCB outperformed manual BacT/ALERT bottles, but the agar slant did not allow earlier detection nor earlier colony growth. Time to detection for manual blood culture systems still lags that of automated systems, and research into innovative and affordable methods of growth detection in manual BCBs is encouraged. Funding: Médecins Sans Frontières and Department of Economy, Science and Innovation of the Flemish Government.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Evaluation of microscan bacterial identification panels for low-resource settings

Bacterial identification is challenging in low-resource settings (LRS). We evaluated the MicroScan identification panels (Beckman Coulter, Brea, CA, USA) as part of Médecins Sans Frontières’ Mini-lab Project. The MicroScan Dried Overnight Positive ID Type 3 (PID3) panels for Gram-positive organisms and Dried Overnight Negative ID Type 2 (NID2) panels for Gram-negative organisms were assessed with 367 clinical isolates from LRS. Robustness was studied by inoculating Gram-negative species on the Gram-positive panel and vice versa. The ease of use of the panels and readability of the instructions for use (IFU) were evaluated. Of species represented in the MicroScan database, 94.6% (185/195) of Gram-negative and 85.9% (110/128) of Gram-positive isolates were correctly identified up to species level. Of species not represented in the database (e.g. Streptococcus suis and Bacillus spp.), 53.1% out of 49 isolates were incorrectly identified as non-related bacterial species. Testing of Gram-positive isolates on Gram-negative panels and vice versa (n = 144) resulted in incorrect identifications for 38.2% of tested isolates. The readability level of the IFU was considered too high for LRS. Inoculation of the panels was favorably evaluated, whereas the visual reading of the panels was considered error-prone. In conclusion, the accuracy of the MicroScan identification panels was excellent for Gram-negative species and good for Gram-positive species. Improvements in stability, robustness, and ease of use have been identified to assure adaptation to LRS constraints.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Best Practices of Blood Cultures in Low- and Middle-Income Countries

Bloodstream infections (BSI) have a substantial impact on morbidity and mortality worldwide. Despite scarcity of data from many low- and middle-income countries (LMICs), there is increasing awareness of the importance of BSI in these countries. For example, it is estimated that the global mortality of non-typhoidal Salmonella bloodstream infection in children under 5 already exceeds that of malaria. Reliable and accurate diagnosis of these infections is therefore of utmost importance. Blood cultures are the reference method for diagnosis of BSI. LMICs face many challenges when implementing blood cultures, due to financial, logistical, and infrastructure-related constraints. This review aims to provide an overview of the state-of-the-art of sampling and processing of blood cultures, with emphasis on its use in LMICs. Laboratory processing of blood cultures is relatively straightforward and can be done without the need for expensive and complicated equipment. Automates for incubation and growth monitoring have become the standard in high-income countries (HICs), but they are still too expensive and not sufficiently robust for imminent implementation in most LMICs. Therefore, this review focuses on "manual" methods of blood culture, not involving automated equipment. In manual blood cultures, a bottle consisting of a broth medium supporting bacterial growth is incubated in a normal incubator and inspected daily for signs of growth. The collection of blood for blood culture is a crucial step in the process, as the sensitivity of blood cultures depends on the volume sampled; furthermore, contamination of the blood culture (accidental inoculation of environmental and skin bacteria) can be avoided by appropriate antisepsis. In this review, we give recommendations regarding appropriate blood culture sampling and processing in LMICs. We present feasible methods to detect and speed up growth and discuss some challenges in implementing blood cultures in LMICs, such as the biosafety aspects, supply chain and waste management.status: publishe

Clinical bacteriology in low-resource settings: today's solutions

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FIRST-IN-MAN OBSERVATION OF TALAROMYCES MARNEFFEI-TRANSMISSION BY ORGAN TRANSPLANTATION

A lung transplant recipient was diagnosed with penicilliosis due to Talaromyces marneffei, a fungus endemic in South-East Asia, which was acquired by donor transmission. This first case of Talaromyces marneffei-transmission by transplantation underscores that current globalisation of travelling necessitates increased vigilance for transmission of unusual pathogens in organ recipients.status: publishe

Evaluation of InTray Cassettes Directly from Blood Cultures for the Diagnosis of Sepsis in Clinical Bacteriology Laboratories as an Alternative to Classic Culture Media

Culture media is fundamental in clinical bacteriology for the detection and isolation of bacterial pathogens. However, in-house media preparation could be challenging in low-resource settings. InTray® cassettes (Biomed Diagnostics) could be a valid alternative as they are compact, ready-to-use media preparations. In this study, we evaluate the use of two InTray media as a subculture alternative for the diagnosis of bloodstream infections: the InTray® Müller-Hinton (MH) chocolate and the InTray® Colorex™ Screen. The InTray MH chocolate was evaluated in 2 steps: firstly, using simulated positive blood cultures (reference evaluation study), and secondly, using positive blood cultures from a routine clinical laboratory (clinical evaluation study). The Colorex Screen was tested using simulated poly-microbial blood cultures. The sensitivity and specificity of the InTray MH chocolate were respectively 99.2% and 90% in the reference evaluation study and 97.1% and 88.2% in the clinical evaluation study. The time to detection (TTD) was ≤20 h in most positive blood cultures (99.8% and 97% in the two studies, respectively). The InTray® MH Chocolate agar showed good performance when used directly from clinical blood cultures for single bacterial infections. However, mixed flora is more challenging to interpret on this media than on Colorex™ Screen, even for an experienced microbiologist