The Novel CarbaLux Test for Carbapenemases and Carbapenem Deactivating AmpC Beta-Lactamases

Objectives: To evaluate the rapid phenotypic CarbaLux test for routine diagnostics in the medical laboratory in a proof of concept study. Methods: isolates of Gram-negative bacteria suspicious for carbapenem resistance including Enterobacterales (67), Pseudomonas (10), Acinetobacter (5), and Stenotrophomonas (1) species, collected between 2016 and 2018 from in-patients, were tested for carbapenemase activity using a novel fluorescent carbapenem. When subjected to extracted bacterial carbapenemases its fluorescence disappears. All bacteria to be tested were cultured on Columbia blood agar and few on other commercial media. MALDI TOF MS, molecular assays, automated MIC testing, and in part, agar diffusion tests served to characterize the isolates. For comparison, few selected bacteria were also investigated by prior phenotypic tests for carbapenemase detection. Results: Under UV light, the CarbaLux test allowed a rapid detection of 39/39 carbapenemase-producing bacteria, including 15 isolates with OXA carbapenemases (e.g., OXA-23, OXA-24/40-like OXA-48-like or OXA-181). Several isolates had low MICs but still expressed carbapenemases. Among Enterobacter spp., it detected six strains with hyper-produced AmpC beta-lactamases, which deactivated carbapenems but were not detectable by prior rapid phenotypic assays. An unexpected high carbapenemase activity appeared with these enzymes. They were identified as AmpC variants by inhibition with cloxacillin. Conclusion: Other than prior rapid phenotypic assessments for carbapenemases, which use secondary effects such as a change of pH, the inactivation of the fluorescent carbapenem substrate can be visualized directly under UV light. The new test works at 100 to 200-fold lower, therapy-like substrate concentrations. It takes advantage of the high substrate affinity to carbapenemases allowing also the detection of less reactive resistance enzymes via a trapping mechanism, even from bacteria, which might appear unsuspicious from initial antibiograms. The novel fluorescence method allows simple and safe handling, reliable readings, and documentation and is suitable for primary testing in the clinical laboratory

High-resistivity metal-oxide films through an interlayer of graphene grown directly on copper electrodes

Functional oxides are important materials for multiple applications in flexible and transparent electronics. Electrically contacting these oxides to form active channels is often challenging as they suffer significant alteration or instabilities when interfaced with metal electrodes. Here, we demonstrate a new scheme to electrically contact thin films of semiconducting zinc tin oxide (ZnSnO) that employs pre-patterned copper electrodes encapsulated by chemical-vapour-deposited graphene. Measurement of over more than 100 channels with varying geometry and nature of contact shows that the bulk resistivity of the ZnSnO channels with graphene/Cu composite is at least two orders of magnitude larger than the same films deposited directly on aluminium (Al) contacts. Moreover, the ZnSnO channels with Cu/graphene contacts showed nearly ohmic transport, in contrast to space-charge-limited conduction observed for other contacting schemes. Our results outline a new application of graphene in a step towards the development of alternative contacting strategies for oxide electronics.S.M.L.P and A.J.F. acknowledge funding from the Engineering and Physical Sciences Research Council and Technology Strategy Board: Ref no.: TS/I001158/1. Printed Logic Supply Chain (FlexIC)—TSB App. No. 155

Electron transport in gated InGaAs and InAsP quantum well wires in selectively-grown InP ridge structures

The purpose of this work is to fabricate ribbon-like InGaAs and InAsP wires embedded in InP ridge structures and investigate their transport properties. The InP ridge structures that contain the wires are selectively grown by chemical beam epitaxy (CBE) on pre-patterned InP substrates. To optimize the growth and micro-fabrication processes for electronic transport, we explore the Ohmic contact resistance, the electron density, and the mobility as a function of the wire width using standard transport and Shubnikov-de Haas measurements. At low temperatures the ridge structures reveal reproducible mesoscopic conductance fluctuations. We also fabricate ridge structures with submicron gate electrodes that exhibit non-leaky gating and good pinch-off characteristics acceptable for device operation. Using such wrap gate electrodes, we demonstrate that the wires can be split to form quantum dots evidenced by Coulomb blockade oscillations in transport measurements.Comment: 5 pages, 4 figures, additional references and improved Fig. 4c, MSS-14 conference, submitted to Physica

Nanoparticulate PdZn as a Novel Catalyst for ZnO Nanowire Growth.

ZnO nanowires have been grown by chemical vapour deposition (CVD) using PdZn bimetallic nanoparticles to catalyse the process. Nanocatalyst particles with mean particle diameters of 2.6 ± 0.3 nm were shown to catalyse the growth process, displaying activities that compare well with those reported for sputtered systems. Since nanowire diameters are linked to catalyst morphology, the size-control we are able to exhibit during particle preparation represents an advantage over existing approaches in terms of controlling nanowire dimensions, which is necessary in order to utilize the nanowires for catalytic or electrical applications.(See supplementary material 1).RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Management of cryotherapy-ineligible women in a "screen-and-treat" cervical cancer prevention program targeting HIV-infected women in Zambia: Lessons from the field

Objective: We demonstrate the feasibility of implementing a referral and management system for cryotherapy-ineligible women in a "screen-and-treat" cervical cancer prevention program targeting HIV-infected women in Zambia. Methods: We established criteria for patient referral, developed a training program for loop electrosurgical excision procedure (LEEP) providers, and adapted LEEP to a resource-constrained setting. Results: We successfully trained 15 nurses to perform visual inspection with acetic acid (VIA) followed by immediate cryotherapy. Women with positive tests but ineligible for cryotherapy were referred for further evaluation. We trained four Zambian physicians to evaluate referrals, perform punch biopsy, LEEP, and manage intra-operative and post-operative complications. From January 2006 through October 2007, a total of 8823 women (41.5% HIV seropositive) were evaluated by nurses in outlying prevention clinics; of these, 1477 (16.7%) were referred for physician evaluation based on established criteria. Of the 875 (59.2% of 1147 referred) that presented for evaluation, 748 (8.4% of total screened) underwent histologic evaluation in the form of punch biopsy or LEEP. Complications associated with LEEP included anesthesia reaction (n = 2) which spontaneously resolved, intra-operative (n = 12) and post-operative (n = 2) bleeding managed by local measures, and post-operative infection (n = 12) managed with antibiotics. Conclusion: With adaptations for a resource-constrained environment, we have demonstrated that performing LEEP is feasible and safe, with low rates of complications that can be managed locally. It is important to establish referral and management systems using LEEP-based excisional evaluation for women with cryotherapy-ineligible lesions in VIA-based "screen-and-treat" protocols nested within HIV-care programs in resource-constrained settings

Advancing Cervical Cancer Prevention Initiatives in Resource-Constrained Settings: Insights from the Cervical Cancer Prevention Program in Zambia

Groesbeck Parham and colleagues describe their Cervical Cancer Prevention Program in Zambia, which has provided services to over 58,000 women over the past five years, and share lessons learned from the program's implementation and integration with existing HIV/AIDS programs

Implementation of 'see-and-treat' cervical cancer prevention services linked to HIV care in Zambia

Greater than 80% of the world's new cases and deaths due to cervical cancer occur in the developing world. No more than 5% of women in these settings are screened for cervical cancer even once in their lifetimes. Earlier attempts to establish population-based cervical cancer prevention programs using cytology screening in resource-limited settings have inevitably fallen short or failed. Although many of the reasons for failure can be attributed to lack of resources and trained manpower, the multiple visit requirements of cytology-based screening programs jeopardizes success and sustainability

ChromID identifies the protein interactome at chromatin marks

ISSN:1546-1696ISSN:1087-015

Myths and misconceptions about cervical cancer among Zambian women: rapid assessment by peer educators.

OBJECTIVE: To make a rapid assessment of the common myths and misconceptions surrounding the causes of cervical cancer and lack of screening among unscreened low-income Zambian women. METHODS: We initiated a door-to-door community-based initiative, led by peer educators, to inform unscreened women about the existence of a new see-and-treat cervical cancer prevention program. During home visits peer educators posed the following two questions to women: 1. What do you think causes cervical cancer? 2. Why haven't you been screened for cervical cancer? The most frequent types of responses gathered in this exercise were analyzed thematically. RESULTS: Peer educators contacted over 1100 unscreened women over a period of two months. Their median age was 33 years, a large majority (58%) were not educated beyond primary school, over two-thirds (71%) did not have monthly incomes over 500,000 Zambian Kwacha (US$100) per month, and just over half (51%) were married and cohabiting with their spouses. Approximately 75% of the women engaged in discussions had heard of cervical cancer and had heard of the new cervical cancer prevention program in the local clinic. The responses of unscreened low-income Zambian women to questions posed by peer educators in urban Lusaka reflect the variety of prevalent 'folk' myths and misconceptions surrounding cervical cancer and its prevention methods. CONCLUSION: The information in our rapid assessment can serve as a basis for developing future educational and intervention campaigns for improving uptake of cervical cancer prevention services in Zambia. It also speaks to the necessity of ensuring that programs addressing women's reproductive health take into account societal inputs at the time they are being developed and implemented. Taking a community-based participatory approach to program development and implementation will help ensure sustainability and impact

EC3-A modern telecommunications matrix for cervical cancer prevention in Zambia

Objectives.: Low physician density, undercapacitated laboratory infrastructures, and limited resources are major limitations to the development and implementation of widely accessible cervical cancer prevention programs in sub-Saharan Africa. Materials and methods.: We developed a system operated by nonphysician health providers that used widely available and affordable communication technology to create locally adaptable and sustainable public sector cervical cancer prevention program in Zambia, one of the world's poorest countries. Results.: Nurses were trained to perform visual inspection with acetic acid aided by digital cervicography using predefined criteria. Electronic digital images (cervigrams) were reviewed with patients, and distance consultation was sought as necessary. Same-visit cryotherapy or referral for further evaluation by a gynecologist was offered. The Zambian system of "electronic cervical cancer control" bypasses many of the historic barriers to the delivery of preventive health care to women in low-resource environments while facilitating monitoring, evaluation, and continued education of primary health care providers, patient education, and medical records documentation. Conclusions.: The electronic cervical cancer control system uses appropriate technology to bridge the gap between screening and diagnosis, thereby facilitating the conduct of "screen-and-treat" programs. The inherent flexibility of the system lends itself to the integration with future infrastructures using rapid molecular human papillomavirus-based screening approaches and wireless telemedicine communications