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57 result(s) for "Alfa, Michelle"
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Contaminated flexible endoscopes: Review of impact of channel sampling methods on culture results and recommendations for root-cause analysis
Recently, infection transmission risk associated with contaminated, patient-ready flexible endoscopes has attracted attention. Outbreaks of multidrug-resistant organisms resulting in infection and/or colonization have been particularly concerning. Recent CDC and FDA recommendations focus on reducing “exogenous” infection transmission and specifically recommend that endoscopy sites have quality systems in place for endoscope reprocessing. Another key recommendation is the culture of patient-ready endoscopes to detect contamination with organisms of concern. Remaining gaps in the guidelines include ensuring that optimal endoscope-channel sample methods are used and ensuring effective root-cause analysis and remediation when contamination is detected. In this review, we summarize the critical aspects of endoscope sample collection and present a practical approach to root-cause analysis and remedial action plans.
A comparative study of the gut microbiota in immune-mediated inflammatory diseases—does a common dysbiosis exist?
Background Immune-mediated inflammatory disease (IMID) represents a substantial health concern. It is widely recognized that IMID patients are at a higher risk for developing secondary inflammation-related conditions. While an ambiguous etiology is common to all IMIDs, in recent years, considerable knowledge has emerged regarding the plausible role of the gut microbiome in IMIDs. This study used 16S rRNA gene amplicon sequencing to compare the gut microbiota of patients with Crohn’s disease (CD; N  = 20), ulcerative colitis (UC; N  = 19), multiple sclerosis (MS; N = 19), and rheumatoid arthritis (RA; N  = 21) versus healthy controls (HC; N  = 23). Biological replicates were collected from participants within a 2-month interval. This study aimed to identify common (or unique) taxonomic biomarkers of IMIDs using both differential abundance testing and a machine learning approach. Results Significant microbial community differences between cohorts were observed (pseudo F  = 4.56; p  = 0.01). Richness and diversity were significantly different between cohorts (pFDR < 0.001) and were lowest in CD while highest in HC. Abundances of Actinomyces , Eggerthella, Clostridium III , Faecalicoccus , and Streptococcus (pFDR < 0.001) were significantly higher in all disease cohorts relative to HC, whereas significantly lower abundances were observed for Gemmiger , Lachnospira , and Sporobacter (pFDR < 0.001). Several taxa were found to be differentially abundant in IMIDs versus HC including significantly higher abundances of Intestinibacter in CD, Bifidobacterium in UC, and unclassified Erysipelotrichaceae in MS and significantly lower abundances of Coprococcus in CD, Dialister in MS, and Roseburia in RA. A machine learning approach to classify disease versus HC was highest for CD (AUC = 0.93 and AUC = 0.95 for OTU and genus features, respectively) followed by MS, RA, and UC. Gemmiger and Faecalicoccus were identified as important features for classification of subjects to CD and HC. In general, features identified by differential abundance testing were consistent with machine learning feature importance. Conclusions This study identified several gut microbial taxa with differential abundance patterns common to IMIDs. We also found differentially abundant taxa between IMIDs. These taxa may serve as biomarkers for the detection and diagnosis of IMIDs and suggest there may be a common component to IMID etiology.
A prospective, multicenter, clinical study of duodenoscope contamination after reprocessing
Several clinical procedures utilize duodenoscopes, which are processed for reuse after the procedures are completed. However, infection outbreaks due to improper duodenoscope processing occur frequently. To address this, we aimed to assess the contamination rates of duodenoscopes after reprocessing in nonoutbreak settings. Prospective study in 16 clinical sites in the United States. We sampled and cultured reprocessed duodenoscopes following the FDA/CDC/ASM guideline; \"Duodenoscope Surveillance Sampling and Culturing - Reducing the Risks of Infection.\" High-concern (HC) organisms were those highly associated with disease, including gram-negative rods, , β-hemolytic , spp, and yeasts. We evaluated duodenoscopes with ≥1 CFU of organisms after reprocessing. The reprocessing environments were also sampled and cultured. We assessed 859 newer-model (NM) duodenoscopes (TJF-Q180V) and 850 older-model (OM) duodenoscopes (TJF-160F/VF); of these, 35 NM samples (4.1%) and 56 OM samples (6.6%) were contaminated with HC organisms. We detected and classified the HC organisms as gastrointestinal (45.4%), human origin (16.7%), environmental (24.1%), waterborne (13.0%), and unidentified (0.9%). We detected an overall HC contamination rate of 5.3% in nonoutbreak settings. Although the relationship between endoscopic contamination and the occurrence of infections remains unclear, attempts should continue to be made to further reduce contamination rates. Additional improvements to the manufacturer's instructions for use, human factors during the reprocessing procedure, ongoing training programs, cleanliness of reprocessing environments, and the design of the distal end of the duodenoscope should be considered.
Increasing levels of Parasutterella in the gut microbiome correlate with improving low-density lipoprotein levels in healthy adults consuming resistant potato starch during a randomised trial
Background Prebiotics, defined as a substrate that is selectively utilized by host microorganisms conferring a health benefit, present a potential option to optimize gut microbiome health. Elucidating the relationship between specific intestinal bacteria, prebiotic intake, and the health of the host remains a primary microbiome research goal. Objective To assess the correlations between gut microbiota, serum health parameters, and prebiotic consumption in healthy adults. Methods We performed ad hoc exploratory analysis of changes in abundance of genera in the gut microbiome of 75 participants from a randomized, placebo-controlled clinical trial that evaluated the effects of resistant potato starch (RPS; MSPrebiotic®, N  = 38) intervention versus a fully digestible placebo ( N  = 37) for which primary and secondary outcomes have previously been published. Pearson correlation analysis was used to identify relationships between health parameters (ie. blood glucose and lipids) and populations of gut bacteria. Results Abundance of Parasutterella (phylum Proteobacteria) tended to increase in the gut microbiome of individuals consuming RPS and those increases in Parasutterella were correlated with reductions in low-density lipoprotein (LDL) levels in participants consuming RPS but not placebo. Segregating RPS-consuming individuals whose LDL levels decreased (ie “Responders”) from those who did not (ie. “Non-Responders”) revealed that LDL Responders had significantly higher levels of Parasutterella both at baseline and after 12 weeks of consuming RPS. Conclusion Our analyses suggest that RPS may help improve LDL levels depending upon the levels of Parasutterella in an individual’s gut microbiome. Trial registration This study protocol was reviewed and approved by Health Canada (Submission #188517; “Notice of Authorization” dated 06/05/13) and registered as NCT01977183 (10/11/13) listed on NIH website: ClinicalTrials.gov. Data generated in this study have been submitted to NCBI ( http://www.ncbi.nlm.nih.gov/bioproject/381931 ). Funding MSP Starch Products Inc.
Consumption of resistant potato starch produces changes in gut microbiota that correlate with improvements in abnormal bowel symptoms: a secondary analysis of a clinical trial
Background Studies have linked a lack of dietary fibre, including resistant starch (RS), to disease-associated changes in intestinal bacteria. Healthy people often report abnormal bowel symptoms (ABS), including bloating, constipation, abdominal pain, and diarrhea, however, connections between these symptoms and the gut microbiota are poorly understood. Determining correlations between ABS and taxonomic groups may provide predictive value for using prebiotics to mitigate ABS in combination with stool microbiome testing. Methods Post hoc analysis of a three-arm randomized, double-blind, placebo-controlled clinical trial evaluating the effects of 3.5 g and 7 g resistant potato starch (RPS) doses or placebo was conducted. The study population ( n  = 70) were healthy adults aged 18–69 years old living in and around Guelph, ON. Participants evaluated their stools using the Bristol Stool Chart and also recorded any ABS daily. The presence of ABS was compared between treatment arms at baseline and changes in ABS were compared within treatment arms over 1- and 4-week periods. Pearson correlation analysis was used to identify significant relationships between changes in ABS and changes in bacterial taxa. Results Abdominal pain, belching, bloating, constipation, diarrhea, gas, and feeling unwell were reported by participants at low levels at baseline. Neither RPS nor placebo had significant effects on mean ABS scores. However, we identified positive correlations between treatment-dependent changes in symptoms and changes in Granulicatella , Haemophilus , Lachnospira , Olsenella , Papillibacter , Turicibacter , unclassified Enterobacteriaceae, unclassified Fusobacteriaceae, unclassified Pasteurellaceae, and unclassified Gammaproteobacteria. We also identified negative correlations between treatment-dependent changes in symptoms and changes in Anaerotruncus , Dorea , RFN20 , Victivallis , unclassified Coriobacteriaceae, and unclassified Oxalobacteraceae. These Pearson correlations were significant after correction for repeated testing. The mean relative abundance of these taxa did not change in response to treatment. Finally, macronutrient intake was unaffected by RPS or placebo treatments. Conclusion Changes in ABS can be positively or negatively correlated with changes in specific gut microbiota, creating opportunities for personalized microbiome-targeted interventions to resolve ABS. Trial Registration The trial was registered at ClinicalTrials.gov (NCT05242913) on February 16, 2022.
Consumption of Solnul™ Resistant Potato Starch Produces a Prebiotic Effect in a Randomized, Placebo-Controlled Clinical Trial
The effects of resistant starch at high doses have been well-characterized, but the potential prebiotic effects of resistant starch at doses comparable to oligosaccharide prebiotics have not been evaluated. A three-arm randomized, double-blind, placebo-controlled clinical trial was conducted to evaluate the effect of 3.5 g and 7 g daily doses of Solnul™ resistant potato starch (RPS) on beneficial populations of gut bacteria and stool consistency after a 4-week period. The relative abundance of Bifidobacterium and Akkermansia was determined by employing 16Sv4 sequencing of stool samples. To assess the effect of RPS on laxation and bowel movements, stools were recorded and scored using the Bristol Stool Form Scale. Participants consuming 3.5 g/day of RPS experienced significantly greater changes in Bifidobacterium and Akkermansia compared to the placebo after 4 weeks. The number of diarrhea- and constipation-associated bowel movements were both significantly lower in the 3.5 g RPS arm compared to the placebo group. Participants consuming 7 g of RPS responded similarly to those in the 3.5 g arm. Our analyses demonstrate that Solnul™ RPS has a prebiotic effect when consumed for 4 weeks at the 3.5 g per day dose, stimulating increases in beneficial health-associated bacteria and reducing diarrhea- and constipation-associated bowel movements when compared to the placebo group.
The polytetrafluoroethylene (PTFE) channel model of cyclic-buildup biofilm and traditional biofilm: The impact of friction, and detergent on cleaning and subsequent high-level disinfection
To evaluate the efficacy of detergent and friction on removal of traditional biofilm and cyclic-buildup biofilm (CBB) from polytetrafluoroethylene (PTFE) channels and to evaluate the efficacy of glutaraldehyde to kill residual bacteria after cleaning. PTFE channels were exposed to artificial test soil containing 108 CFU/mL of Pseudomonas aeruginosa and Enterococcus faecalis, followed by full cleaning and high-level disinfection (HLD) for five repeated rounds to establish CBB. For traditional biofilm, the HLD step was omitted. Cleaning with enzymatic and alkaline detergents, bristle brush, and Pull Thru channel cleaner were compared to a water flush only. Carbohydrate, protein, viable count, adenosine triphosphate (ATP) levels were analyzed and atomic force microscopy (AFM) was performed. In the absence of friction, cleaning of traditional biofilm and CBB was not effective compared to the positive control (Dunn-Bonferroni tests; P > .05) regardless of the detergent used. ATP, protein, and carbohydrate analyses were unable to detect traditional biofilm or CBB. The AFM analysis showed that fixation resulted in CBB being smoother and more compact than traditional biofilm. Friction during the cleaning process was a critical parameter regardless of the detergent used for removal of either traditional biofilm or CBB. Glutaraldehyde effectively killed the remaining microorganisms regardless of the cleaning method used.
Simulated-Use Polytetrafluorethylene Biofilm Model: Repeated Rounds of Complete Reprocessing Lead to Accumulation of Organic Debris and Viable Bacteria
OBJECTIVE Biofilm has been implicated in bacterial persistence and survival after endoscope reprocessing. In this study, we assessed the impact of different methods of reprocessing on organic residues and viable bacteria after repeated rounds of biofilm formation when each was followed by full reprocessing. METHODS ATS-2015, an artificial test soil containing 5-8 Log10 colony-forming units (CFU) of Enterococcus faecalis and Pseudomonas aeruginosa, was used to form biofilm in polytetrafluroethylene channels overnight on 5 successive days. Each successive day, full pump-assisted cleaning using bristle brushes or pull-through devices in combination with enzymatic or nonenzymatic detergents followed by fully automated endoscope reprocessor disinfection using peracetic acid was performed. Residuals were visualized by scanning electron microscopy (SEM). Destructive testing was used to assess expected cutoffs for adenosine triphosphate (ATP; <200 relative light units), protein (<2 µg/cm2), and viable bacteria count (0 CFU). RESULTS Protein residuals were above 2 µg/cm2, but ATP residuals were <200 relative light units for all methods tested. Only when enzymatic cleaner was used for cleaning were there no viable bacteria detected after disinfection irrespective of whether bristle brushes or pull-through devices were used. SEM revealed that some residual debris remained after all reprocessing methods, but more residuals were detected when a nonenzymatic detergent was used. CONCLUSIONS Surviving E. faecalis and P. aeruginosa were only detected when the non-enzymatic detergent was used, emphasizing the importance of the detergent used for endoscope channel reprocessing. Preventing biofilm formation is critical because not all current reprocessing methods can reliably eliminate viable bacteria within the biofilm matrix. Infect Control Hosp Epidemiol 2017;38:1284-1290.
Modeling microbial survival in buildup biofilm for complex medical devices
Background Flexible endoscopes undergo repeated rounds of patient-use and reprocessing. Some evidence indicates that there is an accumulation or build-up of organic material that occurs over time in endoscope channels. This \"buildup biofilm\" (BBF) develops as a result of cyclical exposure to wet and dry phases during usage and reprocessing. This study investigated whether the BBF matrix represents a greater challenge to disinfectant efficacy and microbial eradication than traditional biofilm (TBF), which forms when a surface is constantly bathed in fluid. Methods Using the MBEC (Minimum Biofilm Eradication Concentration) system, a unique modelling approach was developed to evaluate microbial survival in BBF formed by repetitive cycles of drying, disinfectant exposure and re-exposure to the test organism. This model mimics the cumulative effect of the reprocessing protocol on flexible endoscopes. Glutaraldehyde (GLUT) and accelerated hydrogen peroxide (AHP) were evaluated to assess the killing of microbes in TBF and BBF. Results The data showed that the combination of an organic matrix and aldehyde disinfection quickly produced a protective BBF that facilitated high levels of organism survival. In cross-linked BBF formed under high nutrient conditions the maximum colony forming units (CFU) reached ~6 Log 10 CFU/peg. However, if an oxidizing agent was used for disinfection and if organic levels were kept low, organism survival did not occur. A key finding was that once established, the microbial load of BBF formed by GLUT exposure had a faster rate of accumulation than in TBF. The rate of biofilm survival post high-level disinfection (HLD) determined by the maximum Log 10 CFU/initial Log 10 CFU for E. faecalis and P. aeruginosa in BBF was 10 and 8.6 respectively; significantly different compared to a survival rate in TBF of ~2 for each organism. Data from indirect outgrowth testing demonstrated for the first time that there is organism survival in the matrix. Both TBF and BBF had surviving organisms when GLUT was used. For AHP survival was seen less frequently in BBF than in TBF. Conclusion This BBF model demonstrated for the first time that survival of a wide range of microorganisms does occur in BBF, with significantly more rapid outgrowth compared to TBF. This is most pronounced when GLUT is used compared to AHP. The data supports the need for meticulous cleaning of reprocessed endoscopes since the presence of organic material and microorganisms prevents effective disinfection when GLUT and AHP are used. However, cross-linking agents like GLUT are not as effective when there is BBF. The data from the MBEC model of BBF suggest that for flexible endoscopes that are repeatedly used and reprocessed, the assurance of effective high-level disinfection may decrease if BBF develops within the channels.