Tracing the origin of NDM-1-producing and extensively drug-resistant Pseudomonas aeruginosa ST357 in the Netherlands.

BACKGROUND: In the hospital environment, carbapenemase-producing Pseudomonas aeruginosa (CPPA) may lead to fatal patient infections. However, the transmission routes of CPPA often remain unknown. Therefore, this case study aimed to trace the origin of CPPA ST357, which caused a hospital-acquired pneumonia in a repatriated critically ill patient suffering from Guillain-Barré Syndrome in 2023. METHODS: Antimicrobial susceptibility of the CPPA isolate for 30 single and combination therapies was determined by disk-diffusion, Etest or broth microdilution. Whole-genome sequencing was performed for three case CPPA isolates (one patient and two sinks) and four distinct CPPA ST357 patient isolates received in the Dutch CPPA surveillance program. Furthermore, 193 international P. aeruginosa ST357 assemblies were collected via three genome repositories and analyzed using whole-genome multi-locus sequence typing in combination with antimicrobial resistance gene (ARG) characterization. RESULTS: A Dutch patient who carried NDM-1-producing CPPA was transferred from Kenya to the Netherlands, with subsequent dissemination of CPPA isolates to the local sinks within a month after admission. The CPPA case isolates presented an extensively drug-resistant phenotype, with susceptibility only for colistin and cefiderocol-fosfomycin. Phylogenetic analysis showed considerable variation in allelic distances (mean = 150, max = 527 alleles) among the ST357 isolates from Asia (n = 92), Europe (n = 58), Africa (n = 21), America (n = 16), Oceania (n = 2) and unregistered regions (n = 4). However, the case isolates (n = 3) and additional Dutch patient surveillance program isolates (n = 2) were located in a sub-clade of isolates from Kenya (n = 17; varying 15-49 alleles), the United States (n = 7; 21-115 alleles) and other countries (n = 6; 14-121 alleles). This was consistent with previous hospitalization in Kenya of 2/3 Dutch patients. Additionally, over half of the isolates (20/35) in this sub-clade presented an identical resistome with 9/17 Kenyan, 5/5 Dutch, 4/7 United States and 2/6 other countries, which were characterized by the blaNDM-1, aph(3')-VI, ARR-3 and cmlA1 ARGs. CONCLUSION: This study presents an extensively-drug resistant subclone of NDM-producing P. aeruginosa ST357 with a unique resistome which was introduced to the Netherlands via repatriation of critically ill patients from Kenya. Therefore, the monitoring of repatriated patients for CPPA in conjunction with vigilance for the risk of environmental contamination is advisable to detect and prevent further dissemination.

Infants' First Solid Foods: Impact on Gut Microbiota Development in Two Intercontinental Cohorts.

The introduction of solid foods is an important dietary event during infancy that causes profound shifts in the gut microbial composition towards a more adult-like state. Infant gut bacterial dynamics, especially in relation to nutritional intake remain understudied. Over 2 weeks surrounding the time of solid food introduction, the day-to-day dynamics in the gut microbiomes of 24 healthy, full-term infants from the Baby, Food & Mi and LucKi-Gut cohort studies were investigated in relation to their dietary intake. Microbial richness (observed species) and diversity (Shannon index) increased over time and were positively associated with dietary diversity. Microbial community structure (Bray-Curtis dissimilarity) was determined predominantly by individual and age (days). The extent of change in community structure in the introductory period was negatively associated with daily dietary diversity. High daily dietary diversity stabilized the gut microbiome. Bifidobacterial taxa were positively associated, while taxa of the genus Veillonella, that may be the same species, were negatively associated with dietary diversity in both cohorts. This study furthers our understanding of the impact of solid food introduction on gut microbiome development in early life. Dietary diversity seems to have the greatest impact on the gut microbiome as solids are introduced.

Interaction of preservation methods and radiation sterilization in human skin processing, with particular insight on the impact of the final water content and collagen disruption. Part I: process validation, water activity and collagen changes in tissues cryopreserved or processed using 50, 85 or 98% glycerol solutions.

Current regulatory requirements demand an in-depth understanding and validation of protocols used in tissue banking. The aim of this work was to characterize the quality of split thickness skin allografts cryopreserved or manufactured using highly concentrated solutions of glycerol (50, 85 or 98%), where tissue water activity (aw), histology and birefringence changes were chosen as parameters. Consistent aw outcomes validated the proposed processing protocols. While no significant changes in tissue quality were observed under bright-field microscopy or in collagen birefringence, in-process findings can be harnessed to fine-tune and optimize manufacturing outcomes in particular when further radiation sterilization is considered. Furthermore, exposing the tissues to 85% glycerol seems to derive the most efficient outcomes as far as aw and control of microbiological growth.

Intraoperative intorsional traction test of the inferior oblique.

PurposeWe present a novel variation of the traction test of the inferior oblique (IO) muscle. We demonstrate the correlation between the traction test and clinically graded IO overaction and describe the utility of this test to confirm IO weakening.MethodsWe performed a retrospective chart review on all patients who underwent IO surgery and intraoperative intorsion traction tests by a single surgeon over a 10-year period. We compared the traction test results, in 'clock hours' of freedom, before and after IO surgery. We correlated the torsion test at start of surgery with clinical observed IO overaction (scale 0 to +4) in 67 IO operations (56 myectomies, 6 anterior transpositions, 4 myotomies, and 1 recession) and compared to a control group of 23 eyes with minimal or no IO overaction.ResultsThe mean intorsion freedom in the eyes undergoing IO surgery was less than in control eyes (1.63 vs 1.89 clock hour; P<0.00005). There was a significant inverse relationship between grading of clinical IO action and the intorsion test result (Pearson rank coefficient, (r=-0.45; P<0.00001)). Myectomy produced the greatest change in torsion freedom (mean 1.32 clock hour), with all myectomies showing at least 1 clock hour extra freedom after the surgery.ConclusionsThe intorsion traction test confirmed that the IO stiffness correlated with pre-operative IO overaction grade. While it can be helpful in confirming that the entire IO muscle was weakened, it does not substitute for the careful inspection at the end of surgery to ensure there are no remaining IO fibers.

Combining mechanical foaming and thermally induced phase separation to generate chitosan scaffolds for soft tissue engineering.

In this paper, a novel foaming methodology consisting of turbulent mixing and thermally induced phase separation (TIPS) was used to generate scaffolds for tissue engineering. Air bubbles were mechanically introduced into a chitosan solution which forms the continuous polymer/liquid phase in the foam created. The air bubbles entrained in the foam act as a template for the macroporous architecture of the final scaffolds. Wet foams were crosslinked via glutaraldehyde and frozen at -20 °C to induce TIPS in order to limit film drainage, bubble coalescence and Ostwald ripening. The effects of production parameters, including mixing speed, surfactant concentration and chitosan concentration, on foaming are explored. Using this method, hydrogel scaffolds were successfully produced with up to 80% porosity, average pore sizes of 120 µm and readily tuneable compressive modulus in the range of 2.6 to 25 kPa relevant to soft tissue engineering applications. These scaffolds supported 3T3 fibroblast cell proliferation and penetration and therefore show significant potential for application in soft tissue engineering.

An enzyme-responsive controlled release system based on a dual-functional peptide.

A new controlled release system was developed by loading a dual-functional peptide (DFP) on a mesoporous silica material. One-pot synthesis produced a DFP that was stimuli responsive, releasing a therapeutic peptide by protease cleavage. The design provides new steps towards smart biomaterials.

Glaucoma prescribing trends in England 2000 to 2012.

PURPOSE: In 2009, the National Institute for Clinical Excellence (NICE) published guidance on the treatment of ocular hypertension and glaucoma. The aim of the present study was to describe the impact this guidance had on glaucoma prescribing and to describe recent prescribing trends in England. METHOD: Prescribing cost analysis data held by NHS Business Authority for the years 2000-2012 was analysed. RESULTS: The number of prescriptions dispensed increased by 67% from 4.76 million in 2000 to 7.96 million in 2012. Over the same time period, drug costs increased by 88% from £55.2 million to £103.7 million. Prescriptions for prostaglandin analogues increased fourfold, while there was a threefold decrease in the use of beta-blockers. The most commonly prescribed glaucoma medication was latanoprost. The introduction of generic latanoprost in 2012 more than halved the cost associated with this medication. NICE guidance appeared to have had no effect on the total number of prescriptions or the classes of medications prescribed. CONCLUSION: The introduction of the NICE guidelines did not change glaucoma prescribing practice, although it is not clear whether this represents non-adherence to the guidelines or whether the guidelines embodied pre-existing practice.

Force requirements in topical medicine use--the squeezability factor.

INTRODUCTION: Patient compliance is essential to ensure efficacious treatment. The ease of topical drop delivery is of paramount importance. At least 50% of patients report difficulty in self-administration of topical ocular medicine. The two most frequently reported causes of difficulty include aiming the bottle and squeezing the bottle. PURPOSE: The aims of this study were to identify (I) the force required to deliver a single drop from a bottle (the squeezability factor), (II) are some bottle designs easier to use than others? (III) Do compliance aids reduce the finger strength required to deliver an eye drop? METHOD: We measured the force required to deliver a single drop from a variety of commonly used ophthalmic preparations. Force was slowly applied at the midpoint along the bottle until a drop fell from the tip. Compliance aids were also tested with this technique. RESULTS: We report a wide variation in the force requirements needed to use topical medicines. Three of the four compliance aids tested increased force requirements but may have had other beneficial effects by altering the grip on the medicine bottle. CONCLUSION: This study highlights the large variability in force required to deliver a single drop using the ophthalmic preparations and compliance aids tested. We feel our results will be of interest and relevant to prescribing physicians and manufactures alike.

Use of a control test to aid pH assessment of chemical eye injuries.

Chemical burns of the eye represent 7.0%-9.9% of all ocular trauma. Initial management of ocular chemical injuries is irrigation of the eye and conjunctival sac until neutralisation of the tear surface pH is achieved.We present a case of alkali injury in which the raised tear film pH seemed to be unresponsive to irrigation treatment. Suspicion was raised about the accuracy of the litmus paper used to test the tear film pH. The error was confirmed by use of a control litmus pH test of the examining doctor's eyes. Errors in litmus paper pH measurement can occur because of difficulty in matching the paper with scale colours and drying of the paper, which produces a darker colour. A small tear film sample can also create difficulty in colour matching, whereas too large a sample can wash away pigment from the litmus paper. Samples measured too quickly after irrigation can result in a falsely neutral pH measurement. Use of faulty or inappropriate materials can also result in errors. We advocate the use of control litmus pH test in all patients. This would highlight errors in pH measurements and aid in the detection of the end point of irrigation.

Psychosocial needs in renal failure: development of a renal support team.

The purpose of this paper is to illustrate how social, emotional and educational support is provided by the Renal Support Team at Dulwich Hospital to clients approaching or already receiving renal replacement therapy. We aim to illustrate how psychosocial needs were met before the creation of the team, how support has developed since this time and how clients are benefiting from this. We will conclude by discussing some future developments within the team.

Application of self-refocusing band selective RF pulses for spectroscopic localization.

A new self-refocusing slice selection 90 degrees pulse is presented and its incorporation in the SPACE localization sequence described. Experimental comparisons are made with the self-refocusing pulse reported by Geen (H. Geen, S. Wimperis and R. Freeman, J. Magn. Reson. 85, 620 (1990)). The main source of localization error in the SPACE sequence is traced to the hard pi/2 pulse and the development of a shaped-pulse version of the sequence is described. This required the calculation of a slice-selective pulse capable of rotating coherent transverse magnetization to the z-axis. The RF power requirements for these experiments are also discussed.

Temporal relation between energy metabolism and myocardial function during ischemia and reperfusion.

The purpose of the present investigation was to study the relation between energy metabolism and contractile function in the isovolumic guinea pig heart. 31P nuclear magnetic resonance spectroscopy was used to measure changes in the intracellular levels of creatine phosphate, ATP, inorganic phosphate, and pH during 2.43 min total global ischemia and 2.43 min reperfusion, with a time resolution of 9.7 s. From these data, cytosolic changes in the phosphorylation potential, [ATP]-to-[ADP] ratio, free-energy change of ATP hydrolysis, and concentration of free ADP were estimated. The simultaneous monitoring of functional and biochemical parameters allowed them to be directly correlated with respect to time and with respect to each other. No significant changes in ATP were detected at any time, but changes in all other biochemical data were highly correlated with changes in contractile function. Kinetic analysis, using a nonlinear least-squares fit of the experimental points, revealed that the changes in most parameters fitted monoexponential functions. Each parameter was ranked according to its half time, which revealed that the phosphorylation potential was the only metabolic parameter to change at a rate faster than loss of contractile function during ischemia, and all metabolic changes, with the exception of pH, led the recovery of contractile function during reperfusion, the most rapid change occurring in the free ADP concentration. It is concluded that the cytosolic phosphorylation potential controls the contractile function of the heart and that cytosolic free ADP is important in the control of mitochondrial oxidative phosphorylation.

Anthelmintic resistance and sheep management practices in south western Victoria.

Twenty-eight farms in 7 shires in south western Victoria were selected and tested for presence of benzimidazole-resistant nematodes between November 1979 and June 1981. Mean faecal egg counts of sheep were less than 100 strongyloid eggs/g on 11 farms. Faecal egg count reduction tests were conducted on the remaining 17 farms and thiabendazole was less than 90% efficient in reducing egg counts in sheep from 5 (29%) of these farms. Thiabendazole-resistant Teladorsagia circumcincta were identified at necropsy of experimentally infected treated sheep. In further studies a survey of 104 farms was conducted in the Mount Rouse and Dundas shires of western Victoria in 1981 and 1982 respectively to determine the prevalence of anthelmintic resistance in these shires. Mean faecal egg counts among weaner sheep in the winter-spring of both years were less than 100 eggs/g which indicated low levels of parasitic nematode populations. A faecal egg count reduction test was conducted on 10 farms and thiabendazole was less than 90% efficient on 3; levamisole was greater than 90% efficient in all 10 tests. Most of the surveyed farms carried Merino or Merino crossbred sheep at 10 to 15 dry sheep equivalents per ha and weaners were treated with anthelmintics 3 to 6 times per year. Management procedures based mainly on anthelmintic therapy were effective in controlling nematode populations in weaner sheep, although many producers alternated between different groups of anthelmintics within the same year contrary to current recommendations for long-term preservation of anthelmintic efficacy. It was concluded that anthelmintic resistance was not of practical importance to the majority of sheep producers in the region.