scholarly journals Comparison of culture and isolation methods for Clostridioides difficile and other anaerobes from stool samples in a routine microbiological laboratory practice

2021 ◽  
Vol 23 (2) ◽  
pp. 212-216
Author(s):  
Maria G. Shvydkaya ◽  
A.M. Zatevalov ◽  
S.D. Mitrokhin ◽  
D.T. Dzhandarova
Keyword(s):  
Statistical Significance ◽  
Anaerobic Bacteria ◽  
Test Results ◽  
Isolation Rate ◽  
Laboratory Practice ◽  
Clostridioides Difficile ◽  
Pearson Test ◽  
Isolation Methods ◽  
Microbiological Laboratory ◽  
Stool Samples

Objective. To improve stool sample culture and isolation of anaerobic flora, including Clostridioides difficile in the routine microbiological laboratory practice at the children’s oncology hospital. Materials and Methods. A total of 517 stool samples collected from patients in children’s oncology hospital from 2013 to 2015 were studied. All samples were analyzed by ELISA for C. difficile toxins and by culture according to dedicated 5 schemes for isolation of anaerobic bacteria, including C. difficile. Statistical significance of differences in isolation rates between the studied groups (culture schemes) was assessed by Pearson test. Results. Culture in liver broth and covering with technical agar followed by culture on anaerobic agar yielded 100% isolation rate of toxigenic C. difficile strains. This culture scheme is also suitable for isolating concomitant anaerobic flora: non-toxigenic C. difficile strains, Clostridium perfringens, other Clostridia spp. and Bacteroides spp. Conclusions. Use of the liquid accumulation medium and covering with technical agar make it possible to isolate anaerobic flora from stool samples and increase an isolation rate of toxigenic C. difficile strains to 100% of ELISA-positive samples.

scholarly journals Microbiological Characterization and Clinical Outcomes After Extended-Pulsed Fidaxomicin Treatment for Clostridioides difficile Infection in the EXTEND Study

2019 ◽  
Vol 6 (11) ◽  
Author(s):  
Mark H Wilcox ◽  
Oliver A Cornely ◽  
Benoit Guery ◽  
Chris Longshaw ◽  
Areti Georgopali ◽  
...  
Keyword(s):  
Clinical Outcomes ◽  
Statistical Significance ◽  
Clinical Signs ◽  
Signs And Symptoms ◽  
Enzyme Linked Immunosorbent Assay ◽  
Sequencing Analysis ◽  
Toxin A ◽  
Paired Samples ◽  
Clostridioides Difficile ◽  
Stool Samples

Abstract Background Clostridioides (Clostridium) difficile infection (CDI) is diagnosed using clinical signs and symptoms plus positive laboratory tests. Recurrence of CDI after treatment is common, and coinfection with other enteric pathogens may influence clinical outcomes. Methods We aimed to assess rates of C difficile positivity, by enzyme-linked immunosorbent assay (ELISA) toxin A/B and BioFire FilmArray, and the effect of enteric coinfection on clinical outcomes, using samples from the EXTEND study of extended-pulsed fidaxomicin (EPFX) versus standard vancomycin. Results All 356 randomized and treated patients tested positive for C difficile toxin A/B by local tests; a majority (225 of 356, 63.2%) also tested positive by both ELISA and BioFire. Most stool samples taken at screening tested positive for C difficile only using BioFire (EPFX: 112 of 165, 69.7%; vancomycin: 118 of 162, 72.8%). Of the 5 patients who failed treatment and had stool samples available, all (1) had tested negative for C difficile by BioFire at screening and (2) were negative by ELISA at time of treatment failure. When analyzed by BioFire results at screening, rates of sustained clinical cure at 30 days after end of treatment were numerically higher with EPFX than with vancomycin for almost all patients, except for those who tested negative for C difficile but positive for another pathogen. However, these outcome differences by presence of coinfection did not reach statistical significance. Whole-genome sequencing analysis determined that 20 of 26 paired samples from patients with recurrence were reinfections with the same C difficile strain. Conclusions Testing for presence of copathogens in clinical trials of antibiotics could help to explain clinical failures.

scholarly journals Effectiveness of Ultraviolet-C Room Disinfection on Preventing Healthcare-Associated Clostridioides difficile Infection

2020 ◽  
Vol 41 (S1) ◽  
pp. s33-s33
Author(s):  
Michihiko Goto ◽  
Erin Balkenende ◽  
Gosia Clore ◽  
Rajeshwari Nair ◽  
Loretta Simbartl ◽  
...  
Keyword(s):  
Acute Care ◽  
Acute Care Hospitals ◽  
Incidence Rates ◽  
Positive Test ◽  
Negative Binomial Regression Model ◽  
Test Results ◽  
Clostridioides Difficile ◽  
Ultraviolet C ◽  
Healthcare Associated ◽  
Uv C

Background: Enhanced terminal room cleaning with ultraviolet C (UVC) disinfection has become more commonly used as a strategy to reduce the transmission of important nosocomial pathogens, including Clostridioides difficile, but the real-world effectiveness remains unclear. Objectives: We aimed to assess the association of UVC disinfection during terminal cleaning with the incidence of healthcare-associated C. difficile infection and positive test results for C. difficile within the nationwide Veterans Health Administration (VHA) System. Methods: Using a nationwide survey of VHA system acute-care hospitals, information on UV-C system utilization and date of implementation was obtained. Hospital-level incidence rates of clinically confirmed hospital-onset C. difficile infection (HO-CDI) and positive test results with recent healthcare exposures (both hospital-onset [HO-LabID] and community-onset healthcare-associated [CO-HA-LabID]) at acute-care units between January 2010 and December 2018 were obtained through routine surveillance with bed days of care (BDOC) as the denominator. We analyzed the association of UVC disinfection with incidence rates of HO-CDI, HO-Lab-ID, and CO-HA-LabID using a nonrandomized, stepped-wedge design, using negative binomial regression model with hospital-specific random intercept, the presence or absence of UVC disinfection use for each month, with baseline trend and seasonality as explanatory variables. Results: Among 143 VHA acute-care hospitals, 129 hospitals (90.2%) responded to the survey and were included in the analysis. UVC use was reported from 42 hospitals with various implementation start dates (range, June 2010 through June 2017). We identified 23,021 positive C. difficile test results (HO-Lab ID: 5,014) with 16,213 HO-CDI and 24,083,252 BDOC from the 129 hospitals during the study period. There were declining baseline trends nationwide (mean, −0.6% per month) for HO-CDI. The use of UV-C had no statistically significant association with incidence rates of HO-CDI (incidence rate ratio [IRR], 1.032; 95% CI, 0.963–1.106; P = .65) or incidence rates of healthcare-associated positive C. difficile test results (HO-Lab). Conclusions: In this large quasi-experimental analysis within the VHA System, the enhanced terminal room cleaning with UVC disinfection was not associated with the change in incidence rates of clinically confirmed hospital-onset CDI or positive test results with recent healthcare exposure. Further research is needed to understand reasons for lack of effectiveness, such as understanding barriers to utilization.Funding: NoneDisclosures: None

scholarly journals Alpha Is Not the False Alarm Rate: An Activity to Dispel a Common Statistical Misconception

2018 ◽  
Vol 46 (1) ◽  
pp. 72-79 ◽  
Author(s):  
W. Burt Thompson
Keyword(s):  
False Alarm ◽  
False Alarm Rate ◽  
Research Finding ◽  
Statistical Power ◽  
Prior Probability ◽  
Statistical Significance ◽  
Statistical Test ◽  
Test Results ◽  
Web App ◽  
New Research

When a psychologist announces a new research finding, it is often based on a rejected null hypothesis. However, if that hypothesis is true, the claim is a false alarm. Many students mistakenly believe that the probability of committing a false alarm equals alpha, the criterion for statistical significance, which is typically set at 5%. Instructors should take specific steps to dispel this belief because it leads students to misinterpret statistical test results and it reinforces the more general misconception that results can be interpreted in isolation, without reference to theory or prior research. In the present study, students worked with a web app that shows how the false alarm rate is a function of the prior probability of an effect, statistical power, and alpha. Quiz scores suggest the activity helps correct the misconception, which can improve how students conduct and interpret research.

scholarly journals Therapeutic efficacy of connective tissue autotransplants with periosteum and platelet rich plasma in the management of gingival recession

2013 ◽  
Vol 70 (7) ◽  
pp. 664-669 ◽  
Author(s):  
Bojan Jovicic ◽  
Zoran Lazic ◽  
Milica Nedic ◽  
Stevo Matijevic ◽  
Aleksandra Gostovic-Spadijer
Keyword(s):  
Connective Tissue ◽  
Surgical Procedures ◽  
Platelet Rich Plasma ◽  
Statistical Significance ◽  
Surgical Techniques ◽  
Gingival Recession ◽  
Contralateral Side ◽  
Test Results ◽  
Keratinized Tissue ◽  
Student’S T

Background/Aim. Gingival recession progression in clinical practaice has influenced the development of various surgical procedures and techniques for solving esthetic imperfections and subjective difficulties coused by gingival recession. The aim of this study was to verify efficacy of surgical procedures and to compare both of surgical procedures through the keratinized tissue width. Methods. The study included 20 teeth with gingival recesion, M?ller class I and II. Ten teeth with gingival recession were treated with connective tissue autotransplants with periosteum in combination with coronary guided surgical flap (CTG group). On the contralateral side 10 teeth with gingival recession were treated with the same surgical procedures but in combination with platelet-rich plasma (CTGPRP group). We measured the keratinized tissue width. For statistical significance we used the Student's t-test. Results. The study reveled a statistical significance in reducing vertical deepress of recession by both used treatments. Root deepness in CTG and CTG-PRP group was 90% and 93.5%, respectively. With both surgical techniques we achieved larger zone of keratinized gingiva but with a wide zone of keratinized tissue in CTG - the PRP group. Conclusion. The concept regeneration technique with PRP and with the stimulating influence of platele activated growth factors results in the regeneration of deep periodontal tissue as an important prerequisite for the successful treatment of gingival recession.

scholarly journals The assessment of effects of partialling out of socially desirable responding variance on personality traits scores in instructed applicant situations

Psihologija ◽  
2019 ◽  
Vol 52 (3) ◽  
pp. 303-321
Author(s):  
Goran Opacic ◽  
Tatjana Mentus
Keyword(s):  
Personality Traits ◽  
Predictive Validity ◽  
Statistical Significance ◽  
Personality Inventory ◽  
Scale Structure ◽  
Test Results ◽  
Socially Desirable Responding ◽  
Personality Dimensions ◽  
Fake Good

The aim of this study was to examine the extent to which the socially desirable responding (SDR) distorts results of HEDONICA personaliy inventory (acronim based on eight dimensions of this inventory: Honesty, Disintegration, Impulsiveness, Openness, Extraversion, Neuroticism, Conscientiousness, and Agreeableness). The inventory HEDONICA was merged with components of the Balanced Inventory of Desirable Responding (BIDR) as a control inventory and was administered to a sample of 227 students under two experimental situations/ contexts, operationalized by two instructions: the standard (S) one (such as ?be honest?) and the ?fake good? (FG) one (such as ?portray yourself in a most positive way?). Comparing scores in S and FG situations by using MANOVA, a clear distortion on all personality traits in socially desirable directions were evidenced. When, however, the BIDR subscales in the FG situation were entered into MANOVA as covariates, differences between personality scores in S and FG sitautions were considerably reduced, and became statistically insignificant on five personality dimensions. When the variance of dimensions of the BIDR inventory was removed from the variance of HEDONICA traits in FG situation, the change between intercorrelations of personality dimensions in S and FG situations did not attain statistical significance. This lead to the conclusion that the SDR bias, if even does affect test results (i.e., enhances scores in FG situation), does not affect the scale structure and predictive validity of the examined personality inventory.

scholarly journals How the Anaerobic Enteropathogen Clostridioides difficile Tolerates Low O2 Tensions

mBio ◽  
2020 ◽  
Vol 11 (5) ◽  
Author(s):  
Nicolas Kint ◽  
Carolina Alves Feliciano ◽  
Maria C. Martins ◽  
Claire Morvan ◽  
Susana F. Fernandes ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Anaerobic Bacteria ◽  
Growth Defect ◽  
Strictly Anaerobic ◽  
Low Oxygen ◽  
Air Exposure ◽  
Vegetative Cells ◽  
Content Type ◽  
Clostridioides Difficile

ABSTRACT Clostridioides difficile is a major cause of diarrhea associated with antibiotherapy. After germination of C. difficile spores in the small intestine, vegetative cells are exposed to low oxygen (O2) tensions. While considered strictly anaerobic, C. difficile is able to grow in nonstrict anaerobic conditions (1 to 3% O2) and tolerates brief air exposure indicating that this bacterium harbors an arsenal of proteins involved in O2 detoxification and/or protection. Tolerance of C. difficile to low O2 tensions requires the presence of the alternative sigma factor, σB, involved in the general stress response. Among the genes positively controlled by σB, four encode proteins likely involved in O2 detoxification: two flavodiiron proteins (FdpA and FdpF) and two reverse rubrerythrins (revRbr1 and revRbr2). As previously observed for FdpF, we showed that both purified revRbr1 and revRbr2 harbor NADH-linked O2- and H2O2-reductase activities in vitro, while purified FdpA mainly acts as an O2-reductase. The growth of a fdpA mutant is affected at 0.4% O2, while inactivation of both revRbrs leads to a growth defect above 0.1% O2. O2-reductase activities of these different proteins are additive since the quadruple mutant displays a stronger phenotype when exposed to low O2 tensions compared to the triple mutants. Our results demonstrate a key role for revRbrs, FdpF, and FdpA proteins in the ability of C. difficile to grow in the presence of physiological O2 tensions such as those encountered in the colon. IMPORTANCE Although the gastrointestinal tract is regarded as mainly anoxic, low O2 tension is present in the gut and tends to increase following antibiotic-induced disruption of the host microbiota. Two decreasing O2 gradients are observed, a longitudinal one from the small to the large intestine and a second one from the intestinal epithelium toward the colon lumen. Thus, O2 concentration fluctuations within the gastrointestinal tract are a challenge for anaerobic bacteria such as C. difficile. This enteropathogen has developed efficient strategies to detoxify O2. In this work, we identified reverse rubrerythrins and flavodiiron proteins as key actors for O2 tolerance in C. difficile. These enzymes are responsible for the reduction of O2 protecting C. difficile vegetative cells from associated damages. Original and complex detoxification pathways involving O2-reductases are crucial in the ability of C. difficile to tolerate O2 and survive to O2 concentrations encountered in the gastrointestinal tract.

scholarly journals High Agreement Between an Ultrasensitive Clostridioides difficile Toxin Assay and a C. difficile Laboratory Algorithm Utilizing GDH-and-Toxin Enzyme Immunoassays and Cytotoxin Testing

2019 ◽  
Vol 58 (2) ◽  
Author(s):  
Marie L. Landry ◽  
Jeffrey E. Topal ◽  
Joel Estis ◽  
Phoebe Katzenbach ◽  
Niamh Nolan ◽  
...  
Keyword(s):  
Standard Of Care ◽  
Neutralization Assay ◽  
High Agreement ◽  
Content Type ◽  
Clostridioides Difficile ◽  
Automated Assay ◽  
Toxin Assay ◽  
Stool Samples ◽  
Testing Algorithm ◽  
Positive Agreement

ABSTRACT The Singulex Clarity C. diff toxins A/B (Clarity) assay is an automated, ultrasensitive immunoassay for the detection of Clostridioides difficile toxins in stool. In this study, the performance of the Clarity assay was compared to that of a multistep algorithm using an enzyme immunoassay (EIA) for detection of glutamate dehydrogenase (GDH) and toxins A and B arbitrated by a semiquantitative cell cytotoxicity neutralization assay (CCNA). The performance of the assay was evaluated using 211 residual deidentified stool samples tested with a GDH-and-toxin EIA (C. Diff Quik Chek Complete; Techlab), with GDH-and-toxin discordant samples tested with CCNA. The stool samples were stored at –80°C before being tested with the Clarity assay. For samples discordant between Clarity and the standard-of-care algorithm, the samples were tested with PCR (Xpert C. difficile; Cepheid), and chart review was performed. The testing algorithm resulted in 34 GDH+/toxin+, 53 GDH−/toxin−, and 124 GDH+/toxin− samples, of which 39 were CCNA+ and 85 were CCNA−. Clarity had 96.2% negative agreement with GDH−/toxin− samples, 100% positive agreement with GDH+/toxin+ samples, and 95.3% agreement with GDH+/toxin−/CCNA− samples. The Clarity result was invalid for one sample. Clarity agreed with 61.5% of GDH+/toxin−/CCNA+ samples, 90.0% of GDH+/toxin−/CCNA+ (high-positive) samples, and 31.6% of GDH+/toxin−/CCNA+ (low-positive) samples. The Singulex Clarity C. diff toxins A/B assay demonstrated high agreement with a testing algorithm utilizing a GDH-and-toxin EIA and CCNA. This novel automated assay may offer an accurate, stand-alone solution for C. difficile infection (CDI) diagnostics, and further prospective clinical studies are merited.

scholarly journals Bile Acid Profile and its Changes in Response to Cefoperazone Treatment in MR1 Deficient Mice

Metabolites ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 127 ◽  
Author(s):  
Jinchun Sun ◽  
Zhijun Cao ◽  
Ashley D. Smith ◽  
Paul E. Carlson Jr ◽  
Michael Coryell ◽  
...  
Keyword(s):  
Bile Acid ◽  
Intestinal Content ◽  
Knock Out ◽  
Mait Cells ◽  
Clostridioides Difficile ◽  
Clostridioides Difficile Infection ◽  
Infection Resistance ◽  
Stool Samples ◽  
Cecum Content ◽  
Microbiome Data

Mucosal associated invariant T-cells (MAIT cells) are activated following recognition of bacterial antigens (riboflavin intermediates) presented on major histocompatibility complex class I-related molecule (MR1). Our previous study showed that MR1−/− knock-out (KO) mice (lacking MAIT cells) harbor a unique microbiota that is resistant to antibiotic disruption and Clostridioides difficile colonization. While we have characterized the microbiota of this mouse strain, changes in global metabolic activity in these KO mice have not been assessed. Here, LC/MS-based untargeted metabolomics was applied to investigate the differences in the metabolome, specifically in the bile acid (BA) profile of wild-type (WT) and MR1−/− KO mice, as well as how antibiotics change these profiles. BA changes were evaluated in the intestinal content, cecum content, and stool samples from MR1−/− mice and WT mice treated with cefoperazone (Cef). Fecal pellets were collected daily and both intestinal and cecal contents were harvested at predetermined endpoints on day 0 (D0), day 1 (D1), day 3 (D3), and day 5 (D5). KO mice exhibited no changes in 6-hydroxymethyl-8-D-ribityllumazine (rRL-6-CH2OH; an MR1-restricted riboflavin derivative) in the stool samples at either time point vs. D0, while WT mice showed significant decreases in rRL-6-CH2OH in the stool samples on all treatment days vs. D0. Metabolomics analysis from cecal and stool samples showed that KO mice had more total BA intensity (KO/WT = ~1.7 and ~3.3 fold higher) than that from WT mice prior to Cef treatment, while the fold change difference (KO/WT = ~4.5 and ~4.4 fold) increased after five days of Cef treatment. Both KO and WT mice showed decreases in total BA intensity in response to Cef treatment, however, less dramatic decreases were present in KO vs. WT mice. Increases in taurocholic acid (TCA) intensity and decreases in deoxycholic acid (DCA) intensity in the stool samples from WT mice were associated with the depletion of certain gut bacteria, which was consistent with the previously reported microbiome data. Furthermore, the non-detected TCA and relatively higher DCA intensity in the KO mice might be related to Clostridioides difficile infection resistance, although this needs further investigation.

Incidence of Campylobacter jejuni/coli on Pork Carcasses in the Northeast Georgia Area

1985 ◽  
Vol 48 (9) ◽  
pp. 808-810 ◽  
Author(s):  
A. J. BRACEWELL ◽  
J. O. REAGAN ◽  
J. A. CARPENTER ◽  
L. C. BLANKENSHIP
Keyword(s):  
Campylobacter Jejuni ◽  
Campylobacter Coli ◽  
Skin Area ◽  
Isolation Rate ◽  
Direct Plating ◽  
Isolation Methods ◽  
Before And After

One hundred and twelve freshly slaughtered pork carcasses from three packing plants were sampled before and after chilling for the presence of Campylobacter jejuni/coli by the use of two isolation methods (Preston enrichment and Skirrow direct plating). Preston enrichment media gave the highest isolation rate, 12.5%, on freshly slaughtered carcasses. No isolations were obtained from chilled carcasses. More isolates were obtained from the ham skin area compared with the jowl area. All isolates were confirmed as Campylobacter coli.

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