Role of Clostridioides difficile in hospital environment and healthcare workers.

Clostridioides difficile infection (CDI) was traditionally considered to be transmitted within healthcare environment, from other patients or healthcare workers (HCW). Recently, this idea has been challenged. Our objective was to determine the extent of C. difficile contamination in hospital environment with a simplified method for C. difficile recovery. Environmental samples were taken from rooms of patients positive for CDI (Case) and negative for toxigenic C. difficile (Control). Environmental sampling was performed at the time a fecal sample was taken for CDI diagnosis, 48 h after, and 10 days after. HCW hands were also sampled. A total of 476 environmental samples were collected, 246 samples from "Case" rooms and 230 from "Control". Overall, 15.34% of environmental samples were positive for toxigenic C. difficile (TCD), 20.72% of "Case" rooms samples and 9.57% of the samples from "Control" rooms (p = 0.001). When samples from "Case" rooms were analyzed by sampling time, at diagnosis 52.94% were positive, 38.46% were positive at 48 h after symptom resolution and 23.07% were positive after course of treatment. Overall, the most contaminated site corresponded to the bathroom tap, followed by the toilet. We recovered TCD from alcohol-based dispensers and from 4.2% of HCW hands. We found a high proportion of surfaces contaminated with TCD, as well as hand colonization. Notably, even after isolation measures were terminated, there was still TCD contamination.

Faecal microbiota transplantation for recurrent Clostridioides difficile infection: experience with lyophilized oral capsules.

BACKGROUND: Faecal microbiota transplantation (FMT) is a highly effective approach for refractory and recurrent Clostridioides difficile infection (CDI). Despite its excellent efficacy, FMT is not yet a routine procedure in most centres. There is very little experience with FMT based on lyophilized capsules, and data from European institutions are lacking. This article describes our experience with FMT to treat recurrent CDI using lyophilized oral capsules. METHODS: A prospectively recorded single-centre case series of patients with recurrent CDI who underwent FMT between January 2018 and May 2019 were analysed. The primary outcome was defined as resolution of CDI without recurrences over a two-month period. Overall resolution was defined as resolution of diarrhoea without recurrence of CDI within two months after a further cycle of FMT. The FMT process involved oral ingestion of four or five lyophilized capsules in a single dose. All stool donors were rigorously screened. FINDINGS: FMT was performed in 32 patients. Primary cure was achieved in 81.3% of patients, and the overall cure rate was 87.5%. FMT via lyophilized capsules was well tolerated. No FMT procedure-related adverse events and no further complications were observed for lyophilized-capsule FMT. CONCLUSIONS: This initial clinical experience suggests that FMT based on oral lyophilized preparations is a safe, well-tolerated, and highly effective treatment for recurrent CDI. Administration of oral lyophilized capsules seems feasible in hospital routine and will enable FMT to be more widely used.

Clostridioides difficile contamination in a clinical microbiology laboratory?

OBJECTIVES: Clostridioides difficile infection has traditionally been considered to be transmitted predominantly within health-care settings. It is not recognized as a pathogen that presents a risk of laboratory acquisition. Data on laboratory contamination and acquisition by laboratory personnel are lacking. Our objective was to assess environmental contamination by C. difficile and its potential for transmission in a clinical microbiology laboratory. METHODS: Laboratory surfaces were screened for C. difficile. Samples were taken in areas that handle C. difficile isolates (high-exposure (HE) areas), areas adjacent to HE areas or those processing faecal samples (medium-exposure (ME) areas), and areas that do not process faecal samples or C. difficile isolates (low-exposure (LE) areas). We examined C. difficile carriage (hands/rectal samples) of laboratory workers. RESULTS: A total of 140 environmental samples were collected from two HE areas (n = 56), two ME areas (n = 56) and two LE areas (n = 28). Overall, 37.8% (37/98) of surfaces were contaminated with C. difficile, and 17.3% (17/98) with toxigenic C. difficile (TCD). HE areas were significantly more contaminated with TCD than LE areas (38.1% (16/42) versus 0.0% (0/14), p 0.005) and ME areas (38.1% (16/42) versus 2.4% (1/42), p <0.001). Hands were colonized with TCD in 11.8% (4/34) of cases. We found no rectal carriage of C. difficile. CONCLUSIONS: We found a significant proportion of laboratory surfaces to be contaminated with toxigenic C. difficile, as well as hand colonization of laboratory personnel. We recommend specific control measures for high-risk areas and laboratory personnel working in these areas.

Effect of Bias on the Response of GaN Axial p-n Junction Single-Nanowire Photodetectors.

We present a comprehensive study of the performance of GaN single-nanowire photodetectors containing an axial p-n junction. The electrical contact to the p region of the diode is made by including a p+/n+ tunnel junction as cap structure, which allows the use of the same metal scheme to contact both ends of the nanowire. Single-nanowire devices present the rectifying current-voltage characteristic of a p-n diode but their photovoltaic response to ultraviolet radiation scales sublinearly with the incident optical power. This behavior is attributed to the dominant role of surface states. Nevertheless, when the junction is reverse biased, the role of the surface becomes negligible in comparison to the drift of photogenerated carriers in the depletion region. Therefore, the responsivity increases by about 3 orders of magnitude and the photocurrent scales linearly with the excitation. These reverse-biased nanowires display decay times in the range of ∼10 µs, limited by the resistor-capacitor time constant of the setup. Their ultraviolet/visible contrast of several orders of magnitude is suitable for applications requiring high spectral selectivity. When the junction is forward biased, the device behaves as a GaN photoconductor with an increase of the responsivity at the price of a degradation of the time response. The presence of leakage current in some of the wires can be modeled as a shunt resistance which reacts to the radiation as a photoconductor and can dominate the response of the wire even under reverse bias.

Fecal microbiota transplantation for recurrent Clostridium difficile infection: Experience, protocol, and results.

OBJECTIVE: Fecal microbiota transplantation (FMT) is a highly effective therapy for recurrent Clostridium difficile infection (R-CDI). Despite its excellent efficacy, it is still not a routine procedure in most European centers. FMT has not been widely used in Spain to date. We describe our experience with FMT, including a novel approach based on oral fecal capsules. METHODS: We analyzed a prospectively recorded case series of patients with R-CDI treated with FMT at a single center (June 2014-July 2017). Primary outcome was defined as resolution of CDI without recurrence in a two-month period. FMT was administered via colonoscopy, nasojejunal tube, or oral capsules. All stool donors were rigorously screened. RESULTS: FMT was performed in 13 patients with R-CDI. Median age was 75.0 years and 76.9% were females. Six FMT were performed via nasojejunal tube, 5 via oral capsules, and 2 by colonoscopy. There were no procedure-related adverse events, except for bacteremia in one patient. During follow-up, R- CDI was observed in one patient at one month after FMT. The primary resolution rate was 83.3% and the overall resolution rate was 91.7%. FMT by capsules achieved a 100% resolution rate, colonoscopy 100%, and nasojejunal tube 80.0%. CONCLUSIONS: In our cohort, FMT proved to be safe and effective, even in high risk patients. Oral administration in capsules also proved to be safe, well-tolerated, and highly effective for R-CDI. In our experience, the FMT capsule formulation seems feasible in the routine of a hospital. This administration method will allow FMT to be more widely used.

Distribution of Vascular Patterns in Different Subtypes of Renal Cell Carcinoma. A Morphometric Study in Two Distinct Types of Blood Vessels.

To analyze the presence of mature and immature vessels as a prognostic factor in patients with renal cell carcinoma and propose a classification of renal cancer tumor blood vessels according to morphometric parameters. Tissue samples were obtained from 121 renal cell carcinoma patients who underwent radical nephrectomy. Staining with CD31 and CD34 was used to differentiate between immature (CD31+) and mature (CD34+) blood vessels. We quantified the microvascular density, microvascular area and different morphometric parameters: maximum diameter, minimum diameter, major axis, minor axis, perimeter, radius ratio and roundness. We found that the microvascular density was higher in CD31+ than CD34+ vessels, but CD34+ vessels were larger than CD31+ vessels, as well as being strongly correlated with the ISUP tumor grade. We also identified four vascular patterns: pseudoacinar, fascicular, reticular and diffuse. Pseudoacinar and fascicular patterns were more frequent in clear cell renal cell carcinoma (37.62 and 35.64% respectively), followed by reticular pattern (21.78%), while in chromophobe tumors the reticular pattern predominated (90%). The isolated pattern was present in all papillary tumors (100%). In healthy renal tissue, the pseudoacinar and isolated patterns were differentially found in the renal cortex and medulla respectively. We defined four distinct vascular patterns significantly related with the ISUP tumor grade in renal cell carcinomas. Further studies in larger series are needed in order to validate these results. Analysis of both mature and immature vessels (CD34+ and CD31+) provides additional information when evaluating microvascular density.

Rifaximin-resistant Clostridium difficile strains isolated from symptomatic patients.

BACKGROUND: Rifaximin has been proposed as an alternative treatment for specific cases of Clostridium difficile infection (CDI) and intestinal decontamination. Rifaximin-resistant C. difficile has occasionally been reported. Antibiotic susceptibility testing relies on anaerobic agar dilution (reference method), which is cumbersome and not routinely used. There is no commercial test for detection of resistance to rifaximin. OBJECTIVES: To assess resistance to rifaximin by C. difficile and to evaluate the correlation between the results of the rifampicin E-test and susceptibility to rifaximin. METHODS: We compared the in vitro susceptibility of clinical CDI isolates to rifaximin over a 6-month period using the agar dilution method with susceptibility to rifampicin using the E-test. All isolates were characterized using PCR-ribotyping. Clinical data were recorded prospectively. RESULTS: We recovered 276 consecutive C. difficile isolates and found that 32.2% of episodes were caused by rifaximin-resistant strains. The MICs for rifaximin ranged from <0.0009-256 mg/L, with a geometric mean (GM) of 0.256 mg/L, an MIC50/90 of 0.015/>256 mg/L. Rifaximin and rifampicin MICs were comparable, and all strains classed as resistant by agar dilution were correctly classified as resistant by E-test. The most common ribotypes were 001 (37.2%), 078/126 (14.3%), and 014 (12.0%). Ribotype 001 exhibited the highest MICs for rifaximin. CONCLUSIONS: Resistance to rifaximin was common; resistance rates were higher in ribotype 001 strains. Susceptibility to rifaximin determined by agar dilution correlated with susceptibility to rifampicin determined using the E-test, including rifaximin-resistant strains. Our results suggest that the rifampicin E-test is a valid method for the prediction of rifaximin-resistant C. difficile.

Silver-embedded screens in the intensive care unit. A new tool to control multi-drug resistant bacterial cross-transmission.

The purpose of this study was to assess the effectiveness of silver-embedded surfaces (BactiBlock®) to prevent surface colonization by multi-resistant bacteria (MRB) and to reduce the incidence of MRB colonization and infection in patients admitted to an intensive care unit (ICU). A 6-month prospective observational study in a 24-bed mixed ICU divided into two identical subunits (12 beds each) was designed. Seven solid mobile screens were placed in one of the subunits while in the other cloth screens remained. Solid screens were constructed with high-density polyethylene embedded in Bactiblock®. To evaluate the effectiveness of screens coated with Bactiblock®, number of MRB isolates on screens were compared for 6 months. Likewise, numbers of new patients and ICU-stays with MRB colonization in the two subunits were compared. One hundred forty screen samples were collected in 10-point prevalent days. MRB were detected on 28 (20.0%) samples. Over the 70 samples taken on cloth folding screens, MRB were detected in 25 (35.7%), while only 3 (4.3%) of the 70 samples taken on Bactiblock® screens were positive for MRB (p < 0.001). The unit with Bactiblock® screens presented fewer number of ICU stays with MRB colonization (27.8% vs 47.1%; p < 0.001). No significant differences were found in the global incidence of MRB nosocomial infection. The presence of Bactiblock® embedded in solid folding screens avoided MRB surface colonization and reduced MRB transmission to patients admitted to critical care units, proving to be an useful tool in the control of MRB.

Influence of aging and growth hormone on different members of the NFkB family and IkB expression in the heart from a murine model of senescence-accelerated aging.

Inflammation is related to several pathological processes. The aim of this study was to investigate the protein expression of the different subunits of the nuclear factor Kappa b (NFkBp65, p50, p105, p52, p100) and the protein expressions of IkB beta and alpha in the hearts from a murine model of accelerated aging (SAM model) by Western blot. In addition, the translocation of some isoforms of NFkB from cytosol to nuclei (NFkBp65, p50, p52) and ATP level content was studied. In addition we investigated the effect of the chronic administration of growth hormone (GH) on these age-related parameters. SAMP8 and SAMR1 mice of 2 and 10 months of age were used (n = 30). Animals were divided into five experimental groups: 2 old untreated (SAMP8/SAMR1), 2 young control (SAMP8/SAMR1) and one GH treated-old groups (SAMP8). Age-related changes were found in the studied parameters. We were able to see decreases of ATP level contents and the translocation of the nuclear factor kappa B p50, p52 and p65 from cytosol to nuclei in old SAMP8 mice together with a decrease of IKB proteins. However p100 and p105 did not show differences with aging. No significant changes were recorded in SAMR1 animals. GH treatment showed beneficial effects in old SAMP8 mice inducing an increase in ATP levels and inhibiting the translocation of some NFkB subunits such as p52. Our results supported the relation of NFkB activation with enhanced apoptosis and pro-inflammatory status in old SAMP8 mice and suggested a selective beneficial effect of the GH treatment, which was able to partially reduce the incidence of some deleterious changes in the heart of those mice.

IGF-1 deficiency causes atrophic changes associated with upregulation of VGluT1 and downregulation of MEF2 transcription factors in the mouse cochlear nuclei.

Insulin-like growth factor 1 (IGF-1) is a neurotrophic protein that plays a crucial role in modulating neuronal function and synaptic plasticity in the adult brain. Mice lacking the Igf1 gene exhibit profound deafness and multiple anomalies in the inner ear and spiral ganglion. An issue that remains unknown is whether, in addition to these peripheral abnormalities, IGF-1 deficiency also results in structural changes along the central auditory pathway that may contribute to an imbalance between excitation and inhibition, which might be reflected in abnormal auditory brainstem responses (ABR). To assess such a possibility, we evaluated the morphological and physiological alterations in the cochlear nucleus complex of the adult mouse. The expression and distribution of the vesicular glutamate transporter 1 (VGluT1) and the vesicular inhibitory transporter (VGAT), which were used as specific markers for labeling excitatory and inhibitory terminals, and the involvement of the activity-dependent myocyte enhancer factor 2 (MEF2) transcription factors in regulating excitatory synapses were assessed in a 4-month-old mouse model of IGF-1 deficiency and neurosensorial deafness (Igf1 (-/-) homozygous null mice). The results demonstrate decreases in the cochlear nucleus area and cell size along with cell loss in the cochlear nuclei of the deficient mouse. Additionally, our results demonstrate that there is upregulation of VGluT1, but not VGAT, immunostaining and downregulation of MEF2 transcription factors together with increased wave II amplitude in the ABR recording. Our observations provide evidence of an abnormal neuronal cytoarchitecture in the cochlear nuclei of Igf1 (-/-) null mice and suggest that the increased efficacy of glutamatergic synapses might be mediated by MEF2 transcription factors.

Growth hormone replacement therapy prevents sarcopenia by a dual mechanism: improvement of protein balance and of antioxidant defenses.

The aim of our study was to elucidate the role of growth hormone (GH) replacement therapy in three of the main mechanisms involved in sarcopenia: alterations in mitochondrial biogenesis, increase in oxidative stress, and alterations in protein balance. We used young and old Wistar rats that received either placebo or low doses of GH to reach normal insulin-like growth factor-1 values observed in the young group. We found an increase in lean body mass and plasma and hepatic insulin-like growth factor-1 levels in the old animals treated with GH. We also found a lowering of age-associated oxidative damage and an induction of antioxidant enzymes in the skeletal muscle of the treated animals. GH replacement therapy resulted in an increase in the skeletal muscle protein synthesis and mitochondrial biogenesis pathways. This was paralleled by a lowering of inhibitory factors in skeletal muscle regeneration and in protein degradation. GH replacement therapy prevents sarcopenia by acting as a double-edged sword, antioxidant and hypertrophic.

Age-related functional and structural retinal modifications in the Igf1-/- null mouse.

BACKGROUND: Mutations in the gene encoding human insulin-like growth factor-I (IGF-I) cause syndromic neurosensorial deafness. To understand the precise role of IGF-I in retinal physiology, we have studied the morphology and electrophysiology of the retina of the Igf1(-/-) mice in comparison with that of the Igf1(+/-) and Igf1(+/+) animals during aging. METHODS: Serological concentrations of IGF-I, glycemia and body weight were determined in Igf1(+/+), Igf1(+/-) and Igf1(-/-) mice at different times up to 360days of age. We have analyzed hearing by recording the auditory brainstem responses (ABR), the retinal function by electroretinographic (ERG) responses and the retinal morphology by immunohistochemical labeling on retinal preparations at different ages. RESULTS: IGF-I levels are gradually reduced with aging in the mouse. Deaf Igf1(-/-) mice had an almost flat scotopic ERG response and a photopic ERG response of very small amplitude at postnatal age 360days (P360). At the same age, Igf1(+/-) mice still showed both scotopic and photopic ERG responses, but a significant decrease in the ERG wave amplitudes was observed when compared with those of Igf1(+/+) mice. Immunohistochemical analysis showed that P360 Igf1(-/-) mice suffered important structural modifications in the first synapse of the retinal pathway, that affected mainly the postsynaptic processes from horizontal and bipolar cells. A decrease in bassoon and synaptophysin staining in both rod and cone synaptic terminals suggested a reduced photoreceptor output to the inner retina. Retinal morphology of the P360 Igf1(+/-) mice showed only small alterations in the horizontal and bipolar cell processes, when compared with Igf1(+/+) mice of matched age. CONCLUSIONS: In the mouse, IGF-I deficit causes an age-related visual loss, besides a congenital deafness. The present results support the use of the Igf1(-/-) mouse as a new model for the study of human syndromic deaf-blindness.

Covered metal stents for the treatment of biliary complications after orthotopic liver transplantation.

BACKGROUND: Biliary complications, a major source of morbidity after orthotopic liver transplantation (OLT), are increasingly being treated by endoscopic retrograde cholangiopancreatography (ERCP). Endoscopic management has been shown to be superior to percutaneous therapy and surgery. Covered self-expandable metal stents (CSEMSs) may be an alternative to the current endoscopic standard treatment with periodic plastic stent replacement. OBJECTIVE: To assess the safety and efficacy of temporary CSEMS insertion for biliary complications after OLT. METHODS: From November 2001 to December 2009, the 242 OLT performed in 226 patients included 67 cases that developed post-OLT leaks or strictures (29.6%), excluding ischemic biliary complications. CSEMSs were used in 22 patients (33%), 18 male and 4 female, with an overall median age of 55 years (range, 29-69). In-house OLT patients underwent an index ERCP at 26 days (range, 8-784) after OLT. Their records were reviewed to determine ERCP findings, technical success, and clinical outcomes. RESULTS: ERCP with sphincterotomy was performed in all 22 patients, revealing 18 with biliary strictures alone (82%), 3 with strictures and leaks (14%), and 1 with strictures and choledocholithiasis (4%). All strictures were anastomotic. All patients had 1-2 plastic stents inserted across the anastomosis (11 had prior balloon dilation); stones were successfully removed, for an initial technical success rate of 100% (22/22). CSEMSs, were placed at the second ERCP in 14 patients, at the third in 7, and at the fourth in 1. With a median follow-up of 12.5 months (range, 3-25) after CSEMS removal, 21/22 patients (95.5%) remain stricture free and one relapsed, requiring repeat CSEMS insertion. Four patients experienced pain after CSEMS insertion. At CSEMS removal, migration was noted in 5 cases, into either the distal duodenum (n=4) or the proximal biliary tree (n=1), and embedding was seen in 1 case. There were no serious complications; no patients needed hepatojejunostomy. CONCLUSIONS: ERCP is a safe first-line approach for post-OLT biliary complications. It was highly successful in a population with anastomotic leaks and strictures. The therapeutic role of ERCP to manage biliary complications after OLT in the long term is not well known. In our experience, the high rate (close to 95%) of efficacy and its relative safety allowed us to use CSEMS to manage refractory biliary post-OLT strictures. CSEMS insertion may preclude most post-OLT hepatojejunostomies.

A retrospective study of pediatric endoscopy as performed in an adult endoscopy unit.

Gastrointestinal endoscopy is a safe, efficient technique with minimal complications, and a useful diagnostic tool for the pediatric population. Under ideal conditions endoscopies for children should be performed by experienced pediatric endoscopists. In this study we report our experience with pediatric endoscopy at the general adult endoscopy unit in our hospital. Our goal is to quantify the number of endoscopies performed in children, as well as their indications and findings, the type of sedation or anesthesia used, and the time waiting for the test to occur. Our experience demonstrates that endoscopists in a general adult gastroenterology department, working together with pediatricians, may perform a relevant number of endoscopies in children in a fast, safe, effective manner.

Comparison of different aminoglycoside antibiotic treatments to refine ototoxicity studies in adult mice.

Hearing and balance receptors in the inner ear are highly susceptible to damage caused by a wide variety of toxic substances, including aminoglycosides. This class of antibiotics is commonly used in medicine, even though they may produce irreversible bilateral neurosensorial deafness. To identify potential ototoxic agents and novel therapeutic targets, it is necessary to generate standardized animal models of aminoglycoside ototoxicity, which will also serve to explore otic cell repair and regeneration. Although the mouse is the species most often used in biomedical research, due to the genetic information and genetically-modified strains available, there are few standard models of aminoglycoside ototoxicity in adult mice. Most protocols to produce ototoxicity in adult mice employ high doses of aminoglycosides for long periods of time, which causes systemic toxicity, side-effects and high mortality rates. Here, we compare the effects of systemic treatment with four different, yet common, aminoglycoside antibiotics in two mouse strains, evaluating their effects on mortality, cochlear morphology and auditory brainstem responses. Our data indicate that gentamicin and neomycin caused high mortality in the adult mouse without significantly changing the auditory threshold. Amikacin produced a tolerable rate of mortality but at doses that did not exhibit ototoxicity. Finally, intramuscular injection of kanamycin in C57BL/6JOlaHsd mice induced significant dose-dependent bilateral hearing loss with a moderate rate of mortality and less discomfort than following subcutaneous administration.

[PANDAS with a chorea-like clinical presentation and associated autoimmune pathology: a case report]. / PANDAS con clínica tipo corea-like y patología autoinmune asociada: presentación de un caso.

INTRODUCTION: The disorder known as 'PANDAS syndrome' (paediatric autoimmune neuro-psychiatric disorders associated with Streptococci) consists in an abrupt onset of obsessive-compulsive symptoms and/or movement disorders, a pre-puberal onset, and an episodic course. Antibiotic therapy has been postulated as a first choice therapeutic option. A summarised review of main literature on this topic is presented. CASE REPORT: A girl, 10 years and 6 months old, with a dramatic clinical onset of a chorea-like and obsessive-compulsive symptomathology with a remarkable improvement after 10 days penicillin p.o. intake. She has a positive family history of autoimmune disorders, with elevated anti-phospholipidic antibodies. CONCLUSION: The implications of the case follow-up with many relapses, the development of a diabetes after corticoid therapy and the elevated anti glutamic dexcarboxilasa (anti-GAD) are discussed regarding a common underlying autoimmune mechanism.