Evaluating variation in human gut microbiota profiles due to DNA extraction method and inter-subject differences.

PubMed

Wagner Mackenzie, Brett; Waite, David W; Taylor, Michael W

2015-01-01

The human gut contains dense and diverse microbial communities which have profound influences on human health. Gaining meaningful insights into these communities requires provision of high quality microbial nucleic acids from human fecal samples, as well as an understanding of the sources of variation and their impacts on the experimental model. We present here a systematic analysis of commonly used microbial DNA extraction methods, and identify significant sources of variation. Five extraction methods (Human Microbiome Project protocol, MoBio PowerSoil DNA Isolation Kit, QIAamp DNA Stool Mini Kit, ZR Fecal DNA MiniPrep, phenol:chloroform-based DNA isolation) were evaluated based on the following criteria: DNA yield, quality and integrity, and microbial community structure based on Illumina amplicon sequencing of the V4 region of bacterial and archaeal 16S rRNA genes. Our results indicate that the largest portion of variation within the model was attributed to differences between subjects (biological variation), with a smaller proportion of variation associated with DNA extraction method (technical variation) and intra-subject variation. A comprehensive understanding of the potential impact of technical variation on the human gut microbiota will help limit preventable bias, enabling more accurate diversity estimates.

Patient perceptions of stool DNA testing for pan-digestive cancer screening: A survey questionnaire

PubMed Central

Yang, Dennis; Hillman, Shauna L; Harris, Ann M; Sinicrope, Pamela S; Devens, Mary E; Ahlquist, David A

2014-01-01

AIM: To explore patient interest in a potential multi-organ stool-DNA test (MUST) for pan-digestive cancer screening. METHODS: A questionnaire was designed and mailed to 1200 randomly-selected patients from the Mayo Clinic registry. The 29-item survey questionnaire included items related to demographics, knowledge of digestive cancers, personal and family history of cancer, personal concern of cancer, colorectal cancer (CRC) screening behavior, interest in MUST, importance of test features in a cancer screening tool, and comparison of MUST with available CRC screening tests. All responses were summarized descriptively. χ2 and Rank Sum Test were used for categorical and continuous variables, respectively. RESULTS: Completed surveys were returned by 434 (29% aged 50-59, 37% 60-69, 34% 70-79, 52% women). Most participants (98%) responded they would use MUST. In order of importance, respondents rated multi-cancer detection, absence of bowel preparation, safety and noninvasiveness as most attractive characteristics. For CRC screening, MUST was preferred over colorectal-only stool-DNA testing (53%), occult blood testing (75%), colonoscopy (84%), sigmoidoscopy (91%), and barium enema (95%), P < 0.0001 for each. Among those not previously screened, most (96%) indicated they would use MUST if available. Respondents were confident in their ability to follow instructions to perform MUST (98%). Only 9% of respondents indicated that fear of finding cancer was a concern with MUST, and only 3% indicated unpleasantness of stool sampling as a potential barrier. CONCLUSION: Patients are receptive to the concept of MUST, preferred MUST over conventional CRC screening modalities and valued its potential feature of multi-cancer detection. PMID:24803808

DNA from fecal immunochemical test can replace stool for detection of colonic lesions using a microbiota-based model.

PubMed

Baxter, Nielson T; Koumpouras, Charles C; Rogers, Mary A M; Ruffin, Mack T; Schloss, Patrick D

2016-11-14

There is a significant demand for colorectal cancer (CRC) screening methods that are noninvasive, inexpensive, and capable of accurately detecting early stage tumors. It has been shown that models based on the gut microbiota can complement the fecal occult blood test and fecal immunochemical test (FIT). However, a barrier to microbiota-based screening is the need to collect and store a patient's stool sample. Using stool samples collected from 404 patients, we tested whether the residual buffer containing resuspended feces in FIT cartridges could be used in place of intact stool samples. We found that the bacterial DNA isolated from FIT cartridges largely recapitulated the community structure and membership of patients' stool microbiota and that the abundance of bacteria associated with CRC were conserved. We also found that models for detecting CRC that were generated using bacterial abundances from FIT cartridges were equally predictive as models generated using bacterial abundances from stool. These findings demonstrate the potential for using residual buffer from FIT cartridges in place of stool for microbiota-based screening for CRC. This may reduce the need to collect and process separate stool samples and may facilitate combining FIT and microbiota-based biomarkers into a single test. Additionally, FIT cartridges could constitute a novel data source for studying the role of the microbiome in cancer and other diseases.

Medical Surveillance Monthly Report (MSMR). Volume 22, Number 6, June 2015

DTIC Science & Technology

2015-06-01

and then plateaued (with marked year-to-year variability) through 2010 (Figure 2). women and among those who were not deployed within the fi rst...acids were extracted with the QIAamp stool DNA kit (QIAGEN, USA). For the respiratory samples, detection and characterization of human infl uenza...research by the Walter Reed Army Institute of Research Division of Human Subjects Protection. Some of the authors are military service members. Th is

Digital detection of multiple minority mutants in stool DNA for noninvasive colorectal cancer diagnosis.

PubMed

Deng, Lili; Qi, Zongtai; Zou, Binjie; Wu, Haiping; Huang, Huan; Kajiyama, Tomoharu; Kambara, Hideki; Zhou, Guohua

2012-07-03

Somatic mutations in stool DNA are quite specific to colorectal cancer (CRC), but a method being able to detect the extraordinarily low amounts of mutants is challengeable in sensitivity. We proposed a hydrogel bead-array to digitally count CRC-specific mutants in stool at a low cost. At first, multiplex amplification of targets containing multiple mutation loci of interest is carried out by a target enriched multiplex PCR (Tem-PCR), yielding the templates qualified for emulsion PCR (emPCR). Then, after immobilizing the beads from emPCR on a glass surface, the incorporation of Cy3-dUTP into the mutant-specific probes, which are specifically hybridized with the amplified beads from emPCR, is used to color the beads coated with mutants. As all amplified beads are hybridized with the Cy5-labeled universal probe, a mutation rate is readily obtained by digitally counting the beads with different colors (yellow and red). A high specificity of the method is achieved by removing the mismatched probes in a bead-array with electrophoresis. The approach has been used to simultaneously detect 8 mutation loci within the APC, TP53, and KRAS genes in stools from eight CRC patients, and 50% of CRC patients were positively diagnosed; therefore, our method can be a potential tool for the noninvasive diagnosis of CRC.

Early Adoption of a Multitarget Stool DNA Test for Colorectal Cancer Screening.

PubMed

Finney Rutten, Lila J; Jacobson, Robert M; Wilson, Patrick M; Jacobson, Debra J; Fan, Chun; Kisiel, John B; Sweetser, Seth; Tulledge-Scheitel, Sidna M; St Sauver, Jennifer L

2017-05-01

To characterize early adoption of a novel multitarget stool DNA (MT-sDNA) screening test for colorectal cancer (CRC) screening and to test the hypothesis that adoption differs by demographic characteristics and prior CRC screening behavior and proceeds predictably over time. We used the Rochester Epidemiology Project research infrastructure to assess the use of the MT-sDNA screening test in adults aged 50 to 75 years living in Olmsted County, Minnesota, in 2014 and identified 27,147 individuals eligible or due for screening colonoscopy from November 1, 2014, through November 30, 2015. We used electronic Current Procedure Terminology and Health Care Common Procedure codes to evaluate early adoption of the MT-sDNA screening test in this population and to test whether early adoption varies by age, sex, race, and prior CRC screening behavior. Overall, 2193 (8.1%) and 974 (3.6%) individuals were screened by colonoscopy and MT-sDNA, respectively. Age, sex, race, and prior CRC screening behavior were significantly and independently associated with MT-sDNA screening use compared with colonoscopy use after adjustment for all other variables (P<.05 for all). The rates of adoption of MT-sDNA screening increased over time and were highest in those aged 50 to 54 years, women, whites, and those who had a history of screening. The use of the MT-sDNA screening test varied predictably by insurance coverage. The rates of colonoscopy decreased over time, whereas overall CRC screening rates remained steady. The results of the present study are generally consistent with predictions derived from prior research and the diffusion of innovation framework, pointing to increasing use of the new screening test over time and early adoption by younger patients, women, whites, and those with prior CRC screening. Copyright © 2017 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

Detection of KRAS G12D in colorectal cancer stool by droplet digital PCR

PubMed Central

Olmedillas-López, Susana; Lévano-Linares, Dennis César; Alexandre, Carmen Laura Aúz; Vega-Clemente, Luz; Sánchez, Edurne León; Villagrasa, Alejandro; Ruíz-Tovar, Jaime; García-Arranz, Mariano; García-Olmo, Damián

2017-01-01

AIM To assess KRAS G12D mutation detection by droplet digital PCR (ddPCR) in stool-derived DNA from colorectal cancer (CRC) patients. METHODS In this study, tumor tissue and stool samples were collected from 70 patients with stage I-IV CRC diagnosed by preoperative biopsy. KRAS mutational status was determined by pyrosequencing analysis of DNA obtained from formalin-fixed paraffin-embedded (FFPE) tumor tissues. The KRAS G12D mutation was then analyzed by ddPCR in FFPE tumors and stool-derived DNA from patients with this point mutation. Wild-type (WT) tumors, as determined by pyrosequencing, were included as controls; analysis of FFPE tissue and stool-derived DNA by ddPCR was performed for these patients as well. RESULTS Among the total 70 patients included, KRAS mutations were detected by pyrosequencing in 32 (45.71%), whereas 38 (54.29%) had WT tumors. The frequency of KRAS mutations was higher in left-sided tumors (11 located in the right colon, 15 in the left, and 6 in the rectum). The predominant point mutation was KRAS G12D (14.29%, n = 10), which was more frequent in early-stage tumors (I-IIA, n = 7). In agreement with pyrosequencing results, the KRAS G12D mutation was detected by ddPCR in FFPE tumor-derived DNA, and only a residual number of mutated copies was found in WT controls. The KRAS G12D mutation was also detected in stool-derived DNA in 80% of all fecal samples from CRC patients with this point mutation. CONCLUSION ddPCR is a reliable and sensitive method to analyze KRAS G12D mutation in stool-derived DNA from CRC patients, especially at early stages. This non-invasive approach is potentially applicable to other relevant biomarkers for CRC management. PMID:29093617

Analysis of DNA Methylation at Specific Loci in Stool Samples Detects Colorectal Cancer and High-grade Dysplasia in Patients with Inflammatory Bowel Disease.

PubMed

Kisiel, John B; Klepp, Pasquale; Allawi, Hatim T; Taylor, William R; Giakoumopoulos, Maria; Sander, Tamara; Yab, Tracy C; Moum, Bjorn A; Lidgard, Graham P; Brackmann, Stephan; Mahoney, Douglas W; Roseth, Arne; Ahlquist, David A

2018-05-15

Patients with inflammatory bowel diseases (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), are at increased risk for colorectal cancer (CRC). Analyses of DNA methylation patterns in stool samples have been reported to detect CRC in patients with IBD. We sought to validate these findings in larger cohorts and assess the accuracy of analysis of DNA methylation patterns in stool for detection of CRC and high-grade dysplasia (HGD) normalized to methylation level at ZDHHC1. We obtained buffered, frozen stool samples from a United States case-control study and from 2 European surveillance cohorts (referral or population based) of patients with chronic UC (n=248), CD (n=82), indeterminate colitis (n=2), or IBD with primary sclerosing cholangitis (n=38). Stool samples were collected before bowel preparation for colonoscopy or at least 1 week after colonoscopy. Among the study samples, stools from individuals with IBD but without neoplasia were used as controls (n=291). DNA was isolated from stool, exposed to bisulfite, and then assayed by multiplex quantitative allele-specific real-time target and signal amplification. We analyzed methylation levels of BMP3, NDRG4, VAV3, and SFMBT2 relative to the methylation level of ZDHHC1, and compared these between patients with CRC or HGD and controls. Levels of methylation at BMP3 and VAV3, relative to ZDHHC1 methylation, identified patients with CRC and HGD with an area under curve value of 0.91 (95% CI, 0.77-1.00). Methylation levels at specific promotor regions of these genes identified 11 of the 12 patients with CRC and HGD, with 92% sensitivity (95% CI, 60%-100%) and 90% specificity (95% CI, 86%-93%). The proportion of false-positive results did not differ significantly among the case-control, referral cohort, and population cohort studies (P=.60) when the 90% specificity cut-off from the whole sample set was applied. In an analysis of stool samples from 3 independent studies, of 332 patients with IBD, we

Early Adoption of a Multi-target Stool DNA Test for Colorectal Cancer Screening

PubMed Central

Finney Rutten, Lila J.; Jacobson, Robert M.; Wilson, Patrick M.; Jacobson, Debra J.; Fan, Chun; Kisiel, John B.; Sweetser, Seth R.; Tulledge-Scheitel, Sidna M.; St. Sauver, Jennifer L.

2017-01-01

Objective To characterize early adoption of a novelmulti-target stool deoxyribonucleic acid (MTsDNA) screening test for colorectal cancer (CRC) and test the hypothesis that adoption differs by demographic characteristics, prior CRC screening behavior, and proceeds predictably over time. Patients and Methods We used the Rochester Epidemiology Project infrastructure to assess MTsDNA screening test use among adults aged 50–75 years, and identified 27,147 individuals eligible/due for screening colonoscopy from November 1, 2014 through November 30, 2015, and living in Olmsted County, Minnesota in2014. We used electronic Current Procedure Terminology and Health Care Common Procedure codes to evaluate early adoption of MTsDNA screening test in this population and to test whether early adoption varies by age, sex, race, and prior screening behavior. Results Overall, 2,193 (8.1%) and 974 (3.6%) of individuals were screened by colonoscopy and MT-sDNA, respectively. Age, sex, race, and prior screening were significantly and independently associated with MT-sDNA screening use compared to colonoscopy use after adjustment for all other variables. Rates of adoption of MTsDNA screening increased over time and were highest among those aged 50–54 years, females, whites, and had a prior history of screening. MT-sDNA screening use varied predictably by insurance coverage. Rates of colonoscopy decreased over time, while overall CRC screening rates remained steady. Conclusion Our results are generally consistent with predictions derived from prior research and Diffusion of Innovation framework, pointing to increasing use of the new screening test over time, and early adoption by younger patients, females, whites and those with prior CRC screening. PMID:28473037

DNA Extraction from Protozoan Oocysts/Cysts in Feces for Diagnostic PCR

PubMed Central

2014-01-01

PCR detection of intestinal protozoa is often restrained by a poor DNA recovery or by inhibitors present in feces. The need for an extraction protocol that can overcome these obstacles is therefore clear. QIAamp® DNA Stool Mini Kit (Qiagen) was evaluated for its ability to recover DNA from oocysts/cysts directly from feces. Twenty-five Giardia-positive, 15 Cryptosporidium-positive, 15 Entamoeba histolytica-positive, and 45 protozoa-free samples were processed as control by microscopy and immunoassay tests. DNA extracts were amplified using 3 sets of published primers. Following the manufacturer's protocol, the kit showed sensitivity and specificity of 100% towards Giardia and Entamoeba. However, for Cryptosporidium, the sensitivity and specificity were 60% (9/15) and 100%, respectively. A series of optimization experiments involving various steps of the kit's protocol were conducted using Cryptosporidium-positive samples. The best DNA recoveries were gained by raising the lysis temperature to the boiling point for 10 min and the incubation time of the InhibitEX tablet to 5 min. Also, using a pre-cooled ethanol for nucleic acid precipitation and small elution volume (50-100 µl) were valuable. The sensitivity of the amended protocol to Cryptosporidium was raised to 100%. Cryptosporidium DNA was successfully amplified by either the first or the second primer set. When applied on parasite-free feces spiked with variable oocysts/cysts counts, ≈ 2 oocysts/cysts were theoretically enough for detection by PCR. To conclude, the Qiagen kit with the amended protocol was proved to be suitable for protozoan DNA extraction directly from feces and support PCR diagnosis. PMID:25031466

DNA extraction from protozoan oocysts/cysts in feces for diagnostic PCR.

PubMed

Hawash, Yousry

2014-06-01

PCR detection of intestinal protozoa is often restrained by a poor DNA recovery or by inhibitors present in feces. The need for an extraction protocol that can overcome these obstacles is therefore clear. QIAamp® DNA Stool Mini Kit (Qiagen) was evaluated for its ability to recover DNA from oocysts/cysts directly from feces. Twenty-five Giardia-positive, 15 Cryptosporidium-positive, 15 Entamoeba histolytica-positive, and 45 protozoa-free samples were processed as control by microscopy and immunoassay tests. DNA extracts were amplified using 3 sets of published primers. Following the manufacturer's protocol, the kit showed sensitivity and specificity of 100% towards Giardia and Entamoeba. However, for Cryptosporidium, the sensitivity and specificity were 60% (9/15) and 100%, respectively. A series of optimization experiments involving various steps of the kit's protocol were conducted using Cryptosporidium-positive samples. The best DNA recoveries were gained by raising the lysis temperature to the boiling point for 10 min and the incubation time of the InhibitEX tablet to 5 min. Also, using a pre-cooled ethanol for nucleic acid precipitation and small elution volume (50-100 µl) were valuable. The sensitivity of the amended protocol to Cryptosporidium was raised to 100%. Cryptosporidium DNA was successfully amplified by either the first or the second primer set. When applied on parasite-free feces spiked with variable oocysts/cysts counts, ≈ 2 oocysts/cysts were theoretically enough for detection by PCR. To conclude, the Qiagen kit with the amended protocol was proved to be suitable for protozoan DNA extraction directly from feces and support PCR diagnosis.

DNA extraction in Echinococcus granulosus and Taenia spp. eggs in dogs stool samples applying thermal shock.

PubMed

Hidalgo, Alejandro; Melo, Angélica; Romero, Fernando; Hidalgo, Víctor; Villanueva, José; Fonseca-Salamanca, Flery

2018-03-01

The extraction of DNA in taeniid eggs shows complications attached to the composition of stool samples and the high resistance of eggs to degradation. The objective of this study was to test a method of DNA extraction in taeniid eggs by applying a thermal shock to facilitate the chemical-enzymatic degradation of these elements. A group of six tubes containing 1 ml of dog stool sample was spiked with eggs of Echinococcus granulosus and another group of six with Taenia pisiformis. Samples were floated with supersaturated sugar solution and centrifuged. The upper portion of each tube (500 μl) was aspirated and deposited in 1.5 ml tubes. Three tubes from each group were incubated at -20 °C and then at 90 °C, the remaining three from each group, incubated at room temperature. Proteinase K and lysis buffer were added to each tube and incubated for 12 h at 58 °C. The lysis effect was evaluated by microscopy at 3, 6 and 12 h and integrity by electrophoresis in 1% agarose gels. With the same experimental scheme, the thermal shock effect was evaluated in extractions of 1, 2, 3 and 4 eggs of each species and the DNA was quantified. Additionally, the protocol was applied in samples of 4 dogs diagnosed with natural infection by Taeniidae worms. Finally, all the extractions were tested by PCR amplification. Both E. granulosus and T. pisiformis eggs showed a similar response in the tests. In samples without treatment, the lysis effect was poor and showed no differences over time, but in those subjected to thermal shock, eggs degradation increased with time. In both treatments, there was no DNA loss integrity. The protocol applied to limited amounts of eggs yielded PCR products in 100% of the samples exposed to thermal shock, allowing PCR amplifications up to 1 egg. In non-exposed samples, the results were not replicable. However, DNA quantification showed low values in both treatments. In turn, DNA extractions with thermal shock in infected dog samples

Stool-based biomarkers of interstitial cystitis/bladder pain syndrome.

PubMed

Braundmeier-Fleming, A; Russell, Nathan T; Yang, Wenbin; Nas, Megan Y; Yaggie, Ryan E; Berry, Matthew; Bachrach, Laurie; Flury, Sarah C; Marko, Darlene S; Bushell, Colleen B; Welge, Michael E; White, Bryan A; Schaeffer, Anthony J; Klumpp, David J

2016-05-18

Interstitial cystitis/bladder pain syndrome (IC) is associated with significant morbidity, yet underlying mechanisms and diagnostic biomarkers remain unknown. Pelvic organs exhibit neural crosstalk by convergence of visceral sensory pathways, and rodent studies demonstrate distinct bacterial pain phenotypes, suggesting that the microbiome modulates pelvic pain in IC. Stool samples were obtained from female IC patients and healthy controls, and symptom severity was determined by questionnaire. Operational taxonomic units (OTUs) were identified by16S rDNA sequence analysis. Machine learning by Extended Random Forest (ERF) identified OTUs associated with symptom scores. Quantitative PCR of stool DNA with species-specific primer pairs demonstrated significantly reduced levels of E. sinensis, C. aerofaciens, F. prausnitzii, O. splanchnicus, and L. longoviformis in microbiota of IC patients. These species, deficient in IC pelvic pain (DIPP), were further evaluated by Receiver-operator characteristic (ROC) analyses, and DIPP species emerged as potential IC biomarkers. Stool metabolomic studies identified glyceraldehyde as significantly elevated in IC. Metabolomic pathway analysis identified lipid pathways, consistent with predicted metagenome functionality. Together, these findings suggest that DIPP species and metabolites may serve as candidates for novel IC biomarkers in stool. Functional changes in the IC microbiome may also serve as therapeutic targets for treating chronic pelvic pain.

Stool Tests

MedlinePlus

... 2014 More on this topic for: Parents Teens E. Coli Giardiasis Yersiniosis Stool Test: Bacteria Culture Stool Test: ... Stool Test: Ova and Parasites (O&P) Diarrhea E. Coli View more About Us Contact Us Partners Editorial ...

Improved diagnosis of Trichuris trichiura by using a bead-beating procedure on ethanol preserved stool samples prior to DNA isolation and the performance of multiplex real-time PCR for intestinal parasites.

PubMed

Kaisar, Maria M M; Brienen, Eric A T; Djuardi, Yenny; Sartono, Erliyani; Yazdanbakhsh, Maria; Verweij, Jaco J; Supali, Taniawati; VAN Lieshout, Lisette

2017-06-01

For the majority of intestinal parasites, real-time PCR-based diagnosis outperforms microscopy. However, the data for Trichuris trichiura have been less convincing and most comparative studies have been performed in populations with low prevalence. This study aims to improve detection of T. trichuria DNA in human stool by evaluating four sample preparation methods. Faecal samples (n = 60) were collected at Flores island, Indonesia and examined by microscopy. Aliquots were taken and a bead-beating procedure was used both on directly frozen stool and on material preserved with 96% ethanol. PCR on frozen samples showed 40% to be positive for T. trichiura, compared with 45% positive by microscopy. The percentage positive increased when using ethanol preservation (45·0%), bead-beating (51·7%) and a combination (55·0%) and all three methods showed significantly higher DNA loads. The various procedures had a less pronounced effect on the PCR results of nine other parasite targets tested. Most prevalent were Ascaris lumbricoides (≈60%), Necator americanus (≈60%), Dientamoeba fragilis (≈50%) and Giardia lamblia (≈12%). To validate the practicality of the procedure, bead-beating was applied in a population-based survey testing 910 stool samples. Findings confirmed bead-beating before DNA extraction to be a highly efficient procedure for the detection of T. trichiura DNA in stool.

Evaluating Protocols for Porcine Faecal Microbiome Recollection, Storage and DNA Extraction: from the Farm to the Lab.

PubMed

Muiños-Bühl, Anixa; González-Recio, Oscar; Muñoz, María; Óvilo, Cristina; García-Casco, Juan; Fernández, Ana I

2018-06-01

There is a growing interest in understanding the role of the gut microbiome on productive and meat quality-related traits in livestock species in order to develop new useful tools for improving pig production systems and industry. Faecal samples are analysed as a proxy of gut microbiota and here the selection of suitable protocols for faecal sampling and DNA isolation is a critical first step in order to obtain reliable results, even more to compare results obtained from different studies. The aim of the current study was to establish in a cost-effective way, using automated ribosomal intergenic spacer analysis technique, a protocol for porcine faecal sampling and storage at farm and slaughterhouse and to determine the most efficient microbiota DNA isolation kit among those most widely used. Operational Taxonomic Unit profiles were compared from Iberian pig faecal samples collected from rectum or ground, stored with liquid N 2 , room temperature or RNAlater, and processed with QIAamp DNA Stool (Qiagen), PowerFecal DNA Isolation (Mobio) or SpeedTools Tissue DNA extraction (Biotools) commercial kits. The results, focused on prokaryote sampling, based on DNA yield and quality, OTU number and Sørensen similarity Indexes, indicate that the recommended protocol for porcine faecal microbiome sampling at farm should include: the collection from porcine rectum to avoid contamination; the storage in liquid N 2 or even at room temperature, but not in RNAlater; and the isolation of microbiota DNA using PowerFecal DNA Isolation kit. These conditions provide more reliable DNA samples for further microbiome analysis.

Multitarget stool DNA tests increases colorectal cancer screening among previously noncompliant Medicare patients

PubMed Central

Prince, Mark; Lester, Lynn; Chiniwala, Rupal; Berger, Barry

2017-01-01

AIM To determine the uptake of noninvasive multitarget stool DNA (mt-sDNA) in a cohort of colorectal cancer (CRC) screening non-compliant average-risk Medicare patients. METHODS This cross sectional primary care office-based study examined mt-sDNA uptake in routine clinical practice among 393 colorectal cancer screening non-compliant Medicare patients ages 50-85 ordered by 77 physicians in a multispecialty group practice (USMD Physician Services, Dallas, TX) from October, 2014-September, 2015. Investigators performed a Health Insurance Portability and Accountability Act compliant retrospective review of electronic health records to identify mt-sDNA use in patients who were either > 10 years since last colonoscopy and/or > 1 year since last fecal occult blood test. Test positive patients were advised to get diagnostic colonoscopy and thereafter patients were characterized by the most clinically significant lesion documented on histopathology of biopsies or excisional tissue. Descriptive statistics were employed. Key outcome measures included mt-sDNA compliance and diagnostic colonoscopy compliance on positive cases. RESULTS Over 12 mo, 77 providers ordered 393 mt-sDNA studies with 347 completed (88.3% compliance). Patient mean age was 69.8 (50-85) and patients were 64% female. Mt-sDNA was negative in 85.3% (296/347) and positive in 14.7% (51/347). Follow-up colonoscopy was performed in 49 positive patients (96.1% colonoscopy compliance) with two patients lost to follow up. Index findings included: colon cancer (4/49, 8.2%), advanced adenomas (21/49, 42.9%), non-advanced adenomas (15/49, 30.6%), and negative results (9/49, 18.4%). The positive predictive value for advanced colorectal lesions was 51.0% and for any colorectal neoplasia was 81.6%. The mean age of patients with colorectal cancer was 70.3 and all CRC's were localized Stage I (2) and Stage II (2), three were located in the proximal colon and one was located in the distal colon. CONCLUSION Mt-sDNA provided

Multitarget stool DNA tests increases colorectal cancer screening among previously noncompliant Medicare patients.

PubMed

Prince, Mark; Lester, Lynn; Chiniwala, Rupal; Berger, Barry

2017-01-21

To determine the uptake of noninvasive multitarget stool DNA (mt-sDNA) in a cohort of colorectal cancer (CRC) screening non-compliant average-risk Medicare patients. This cross sectional primary care office-based study examined mt-sDNA uptake in routine clinical practice among 393 colorectal cancer screening non-compliant Medicare patients ages 50-85 ordered by 77 physicians in a multispecialty group practice (USMD Physician Services, Dallas, TX) from October, 2014-September, 2015. Investigators performed a Health Insurance Portability and Accountability Act compliant retrospective review of electronic health records to identify mt-sDNA use in patients who were either > 10 years since last colonoscopy and/or > 1 year since last fecal occult blood test. Test positive patients were advised to get diagnostic colonoscopy and thereafter patients were characterized by the most clinically significant lesion documented on histopathology of biopsies or excisional tissue. Descriptive statistics were employed. Key outcome measures included mt-sDNA compliance and diagnostic colonoscopy compliance on positive cases. Over 12 mo, 77 providers ordered 393 mt-sDNA studies with 347 completed (88.3% compliance). Patient mean age was 69.8 (50-85) and patients were 64% female. Mt-sDNA was negative in 85.3% (296/347) and positive in 14.7% (51/347). Follow-up colonoscopy was performed in 49 positive patients (96.1% colonoscopy compliance) with two patients lost to follow up. Index findings included: colon cancer (4/49, 8.2%), advanced adenomas (21/49, 42.9%), non-advanced adenomas (15/49, 30.6%), and negative results (9/49, 18.4%). The positive predictive value for advanced colorectal lesions was 51.0% and for any colorectal neoplasia was 81.6%. The mean age of patients with colorectal cancer was 70.3 and all CRC's were localized Stage I (2) and Stage II (2), three were located in the proximal colon and one was located in the distal colon. Mt-sDNA provided medical benefit to screening

Validation of methylation-sensitive high-resolution melting (MS-HRM) for the detection of stool DNA methylation in colorectal neoplasms.

PubMed

Xiao, Zhujun; Li, Bingsheng; Wang, Guozhen; Zhu, Weisi; Wang, Zhongqiu; Lin, Jinfeng; Xu, Angao; Wang, Xinying

2014-04-20

Methylation-sensitive high-resolution melting (MS-HRM) is a new technique for assaying DNA methylation, but its feasibility for assaying stool in patients with colorectal cancer (CRC) is unknown. First, the MS-HRM and methylation-specific PCR (MSP) detection limits were tested. Second, the methylation statuses of SFRP2 and VIM were analyzed in stool samples by MS-HRM, and in matching tumor and normal colon tissues via bisulfite sequencing PCR (BSP). Third, a case-control study evaluated the diagnostic sensitivity and specificity of MS-HRM relative to results obtained with MSP and the fecal immunochemical test (FIT). Finally, the linearity and reproducibility of MS-HRM were assessed. The detection limits of MS-HRM and MSP were 1% and 5%, respectively. The diagnostic sensitivities of MS-HRM (87.3%, 55/63) in stool and BSP in matching tumor tissue (92.1%, 58/63) were highly consistent (κ=0.744). The MS-HRM assay detected 92.5% (37/40) methylation in CRCs, 94.4% (34/36) in advanced adenomas, and 8.8% (5/57) in normal controls. The results of MS-HRM analysis were stable and reliable and showed fairly good linearity for both SFRP2 (P<0.001, R(2)=0.957) and VIM (P<0.001, R(2)=0.954). MS-HRM shows potential for CRC screening. Copyright © 2014 Elsevier B.V. All rights reserved.

Diagnosis of amphimeriasis by LAMPhimerus assay in human stool samples long-term storage onto filter paper

PubMed Central

Calvopiña, Manuel; Buendía-Sánchez, María; López-Abán, Julio; Vicente, Belén; Muro, Antonio

2018-01-01

Amphimeriasis, a fish-borne zoonotic disease caused by the liver fluke Amphimerus spp., has recently been reported as an emerging disease affecting an indigenous Ameridian group, the Chachi, living in Ecuador. The only method for diagnosing amphimeriasis was the microscopic detection of eggs from the parasite in patients' stool samples with very low sensitivity. Our group developed an ELISA technique for detection of anti-Amphimerus IgG in human sera and a molecular method based on LAMP technology (named LAMPhimerus) for specific and sensitive parasite DNA detection. The LAMPhimerus method showed to be much more sensitive than classical parasitological methods for amphimeriasis diagnosis using human stool samples for analysis. The objective of this work is to demonstrate the feasibility of using dried stool samples on filter paper as source of DNA in combination with the effectiveness of our previously designed LAMPhimerus assay for successfully Amphimerus sp. detection in clinical stool samples. A total of 102 untreated and undiluted stool samples collected from Chachi population were spread as thin layer onto common filter paper for easily transportation to our laboratory and stored at room temperature for one year until DNA extraction. When LAMPhimerus method was applied for Amphimerus sp. DNA detection, a higher number of positive results was detected (61/102; 59.80%) in comparison to parasitological methods (38/102; 37.25%), including 28/61 (45.90%) microscopy-confirmed Amphimerus sp. infections. The diagnostic parameters for the sensitivity and specificity werecalculated for our LAMPhimerus assay, which were 79.17% and 65.98%, respectively. We demonstrate, for the first time, that common filter paper is useful for easy collection and long-term storage of human stool samples for later DNA extraction and molecular analysis of human-parasitic trematode eggs. This simple, economic and easily handling method combined with the specific and sensible LAMPhimerus

Enterococcus caccae sp. nov., isolated from human stools.

PubMed

Carvalho, Maria da Glória S; Shewmaker, P Lynn; Steigerwalt, Arnold G; Morey, Roger E; Sampson, A J; Joyce, Kevin; Barrett, Timothy J; Teixeira, Lucia M; Facklam, Richard R

2006-07-01

The National Antimicrobial Resistance Monitoring System Laboratory at the Centers for Disease Control and Prevention (CDC) isolated two enterococcus-like strains that were referred to the CDC Streptococcus Laboratory for further identification. The isolates were recovered from human stool samples collected on different occasions from the same individual in Portland (OR, USA) in July 2000. Conventional physiological tests distinguished these strains from all known species of enterococci. Analyses of whole-cell-protein electrophoretic profiles showed the same unique profile for the two isolates, being most similar those of Enterococcus moraviensis and Enterococcus haemoperoxidus albeit not close enough to allow conclusive inclusion in any enterococcal species. Both isolates gave positive results in tests using the AccuProbe Enterococcus genetic probe, and Lancefield extracts reacted with CDC group D antiserum. Comparative 16S rRNA gene sequencing studies also revealed that these strains were closely related to the species E. moraviensis (99.6 % identity). The results of DNA-DNA relatedness experiments confirmed that these strains represented a single novel taxon. The highest level of DNA-DNA relatedness found between the novel taxon and any of the currently recognized species of Enterococcus was 32 %, for both E. moraviensis and E. haemoperoxidus. On the basis of this evidence, it is proposed that these stool isolates constitute a novel species, for which the name Enterococcus caccae sp. nov. is proposed. The type strain is 2215-02(T) (=SS-1777(T)=ATCC BAA-1240(T)=CCUG 51564(T)).

Evaluation of a shortened QIAsymphony DNA extraction protocol for stool samples using a multiplex real-time PCR for the detection of enteric pathogens.

PubMed

van Zanten, E; Wisselink, G J; Stoll, S; Alvarez, R; Kooistra-Smid, A M D

2011-02-01

A shortened DNA extraction protocol for the QIAsymphony SP was evaluated by quantitative and qualitative comparison of real-time PCR results of 150 co-extracted stool samples. The average ∆Cycle threshold value for positive pathogenic targets was 0.28 Ct. A consensus of 96.91%, with a correlation coefficient of 0.9880 was recorded. Copyright © 2010 Elsevier B.V. All rights reserved.

Successful collection of stool samples for microbiome analyses from a large community-based population of elderly men.

PubMed

Abrahamson, Melanie; Hooker, Elizabeth; Ajami, Nadim J; Petrosino, Joseph F; Orwoll, Eric S

2017-09-01

The relationship of the gastrointestinal microbiome to health and disease is of major research interest, including the effects of the gut microbiota on age related conditions. Here we report on the outcome of a project to collect stool samples on a large number of community dwelling elderly men using the OMNIgene-GUT stool/feces collection kit (OMR-200, DNA Genotek, Ottawa, Canada). Among 1,328 men who were eligible for stool collection, 982 (74%) agreed to participate and 951 submitted samples. The collection process was reported to be acceptable, almost all samples obtained were adequate, the process of sample handling by mail was uniformly successful. The DNA obtained provided excellent results in microbiome analyses, yielding an abundance of species and a diversity of taxa as would be predicted. Our results suggest that population studies of older participants involving remote stool sample collection are feasible. These approaches would allow large scale research projects of the association of the gut microbiota with important clinical outcomes.

Comparison of different approaches to quantitative adenovirus detection in stool specimens of hematopoietic stem cell transplant recipients.

PubMed

Kosulin, K; Dworzak, S; Lawitschka, A; Matthes-Leodolter, S; Lion, T

2016-12-01

Adenoviruses almost invariably proliferate in the gastrointestinal tract prior to dissemination, and critical threshold concentrations in stool correlate with the risk of viremia. Monitoring of adenovirus loads in stool may therefore be important for timely initiation of treatment in order to prevent invasive infection. Comparison of a manual DNA extraction kit in combination with a validated in-house PCR assay with automated extraction on the NucliSENS-EasyMAG device coupled with the Adenovirus R-gene kit (bioMérieux) for quantitative adenovirus analysis in stool samples. Stool specimens spiked with adenovirus concentrations in a range from 10E2-10E11 copies/g and 32 adenovirus-positive clinical stool specimens from pediatric stem cell transplant recipients were tested along with appropriate negative controls. Quantitative analysis of viral load in adenovirus-positive stool specimens revealed a median difference of 0.5 logs (range 0.1-2.2) between the detection systems tested and a difference of 0.3 logs (range 0.0-1.7) when the comparison was restricted to the PCR assays only. Spiking experiments showed a detection limit of 10 2 -10 3 adenovirus copies/g stool revealing a somewhat higher sensitivity offered by the automated extraction. The dynamic range of accurate quantitative analysis by both systems investigated was between 10 3 and 10 8 virus copies/g. The differences in quantitative analysis of adenovirus copy numbers between the systems tested were primarily attributable to the DNA extraction method used, while the qPCR assays revealed a high level of concordance. Both systems showed adequate performance for detection and monitoring of adenoviral load in stool specimens. Copyright © 2016 Elsevier B.V. All rights reserved.

Stool Color: When to Worry

MedlinePlus

Stool color: When to worry Yesterday, my stool color was bright green. Should I be concerned? Answers from Michael ... M.D. Stool comes in a range of colors. All shades of brown and even green are ...

Bristol Stool Form Scale reliability and agreement decreases when determining Rome III stool form designations

USDA-ARS?s Scientific Manuscript database

Rater reproducibility of the Bristol Stool Form Scale (BSFS), which categorizes stools into one of seven types, is unknown. We sought to determine reliability and agreement by individual stool type and when responses are categorized by Rome III clinical designation as normal or abnormal (constipatio...

An optimized work-flow to reduce time-to-detection of carbapenemase-producing Enterobacteriaceae (CPE) using direct testing from rectal swabs.

PubMed

O'Connor, C; Kiernan, M G; Finnegan, C; O'Hara, M; Power, L; O'Connell, N H; Dunne, C P

2017-05-04

Rapid detection of patients with carbapenemase-producing Enterobacteriaceae (CPE) is essential for the prevention of nosocomial cross-transmission, allocation of isolation facilities and to protect patient safety. Here, we aimed to design a new laboratory work-flow, utilizing existing laboratory resources, in order to reduce time-to-diagnosis of CPE. A review of the current CPE testing processes and of the literature was performed to identify a real-time commercial polymerase chain reaction (PCR) assay that could facilitate batch testing of CPE clinical specimens, with adequate CPE gene coverage. Stool specimens (210) were collected; CPE-positive inpatients (n = 10) and anonymized community stool specimens (n = 200). Rectal swabs (eSwab™) were inoculated from collected stool specimens and a manual DNA extraction method (QIAamp® DNA Stool Mini Kit) was employed. Extracted DNA was then processed on the Check-Direct CPE® assay. The three step process of making the eSwab™, extracting DNA manually and running the Check-Direct CPE® assay, took <5 min, 1 h 30 min and 1 h 50 min, respectively. It was time efficient with a result available in under 4 h, comparing favourably with the existing method of CPE screening; average time-to-diagnosis of 48/72 h. Utilizing this CPE work-flow would allow a 'same-day' result. Antimicrobial susceptibility testing results, as is current practice, would remain a 'next-day' result. In conclusion, the Check-Direct CPE® assay was easily integrated into a local laboratory work-flow and could facilitate a large volume of CPE screening specimens in a single batch, making it cost-effective and convenient for daily CPE testing.

21 CFR 868.6700 - Anesthesia stool.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthesia stool. 868.6700 Section 868.6700 Food... DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6700 Anesthesia stool. (a) Identification. An anesthesia stool is a device intended for use as a stool for the anesthesiologist in the operating room. (b...

21 CFR 868.6700 - Anesthesia stool.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Anesthesia stool. 868.6700 Section 868.6700 Food... DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6700 Anesthesia stool. (a) Identification. An anesthesia stool is a device intended for use as a stool for the anesthesiologist in the operating room. (b...

21 CFR 868.6700 - Anesthesia stool.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Anesthesia stool. 868.6700 Section 868.6700 Food... DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6700 Anesthesia stool. (a) Identification. An anesthesia stool is a device intended for use as a stool for the anesthesiologist in the operating room. (b...

21 CFR 868.6700 - Anesthesia stool.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Anesthesia stool. 868.6700 Section 868.6700 Food... DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6700 Anesthesia stool. (a) Identification. An anesthesia stool is a device intended for use as a stool for the anesthesiologist in the operating room. (b...

21 CFR 868.6700 - Anesthesia stool.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Anesthesia stool. 868.6700 Section 868.6700 Food... DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6700 Anesthesia stool. (a) Identification. An anesthesia stool is a device intended for use as a stool for the anesthesiologist in the operating room. (b...

Use of DNA from human stools to detect aberrant CpG island methylation of genes implicated in colorectal cancer.

PubMed

Belshaw, Nigel J; Elliott, Giles O; Williams, Elizabeth A; Bradburn, David M; Mills, Sarah J; Mathers, John C; Johnson, Ian T

2004-09-01

Hypermethylation of cytosine residues in the CpG islands of tumor suppressor genes is a key mechanism of colorectal carcinogenesis. Detection and quantification of CpG island methylation in human DNA isolated from stools might provide a novel strategy for the detection and investigation of colorectal neoplasia. To explore the feasibility of this approach, colorectal biopsies and fecal samples were obtained from 32 patients attending for colonoscopy or surgery, who were found to have adenomatous polyps, colorectal cancer, or no evidence of neoplasia. A further 18 fecal samples were obtained from healthy volunteers, with no bowel symptoms. Isolated DNA was modified with sodium bisulfite and analyzed by methylation-specific PCR and combined bisulfite restriction analysis for CpG island methylation of ESR1, MGMT, HPP1, p16(INK4a), APC, and MLH1. CpG island methylation was readily detectable in both mucosal and fecal DNA with methylation-specific PCR. Using combined bisulfite restriction analysis, it was established that, in volunteers from whom biopsies were available, the levels of methylation at two CpG sites within ESR1 assayed using fecal DNA were significantly correlated with methylation in DNA from colorectal mucosa. Thus, noninvasive techniques can be used to obtain quantitative information about the level of CpG island methylation in human colorectal mucosa. The methods described here could be applied to a much expanded range of genes and may be valuable both for screening purposes and to provide greater insight into the functional consequences of epigenetic changes in the colorectal mucosa of free-living individuals.

An Optimized DNA Analysis Workflow for the Sampling, Extraction, and Concentration of DNA obtained from Archived Latent Fingerprints.

PubMed

Solomon, April D; Hytinen, Madison E; McClain, Aryn M; Miller, Marilyn T; Dawson Cruz, Tracey

2018-01-01

DNA profiles have been obtained from fingerprints, but there is limited knowledge regarding DNA analysis from archived latent fingerprints-touch DNA "sandwiched" between adhesive and paper. Thus, this study sought to comparatively analyze a variety of collection and analytical methods in an effort to seek an optimized workflow for this specific sample type. Untreated and treated archived latent fingerprints were utilized to compare different biological sampling techniques, swab diluents, DNA extraction systems, DNA concentration practices, and post-amplification purification methods. Archived latent fingerprints disassembled and sampled via direct cutting, followed by DNA extracted using the QIAamp® DNA Investigator Kit, and concentration with Centri-Sep™ columns increased the odds of obtaining an STR profile. Using the recommended DNA workflow, 9 of the 10 samples provided STR profiles, which included 7-100% of the expected STR alleles and two full profiles. Thus, with carefully selected procedures, archived latent fingerprints can be a viable DNA source for criminal investigations including cold/postconviction cases. © 2017 American Academy of Forensic Sciences.

Strong-LAMP: A LAMP Assay for Strongyloides spp. Detection in Stool and Urine Samples. Towards the Diagnosis of Human Strongyloidiasis Starting from a Rodent Model.

PubMed

Fernández-Soto, Pedro; Sánchez-Hernández, Alicia; Gandasegui, Javier; Bajo Santos, Cristina; López-Abán, Julio; Saugar, José María; Rodríguez, Esperanza; Vicente, Belén; Muro, Antonio

2016-07-01

Strongyloides stercoralis, the chief causative agent of human strongyloidiasis, is a nematode globally distributed but mainly endemic in tropical and subtropical regions. Chronic infection is often clinically asymptomatic but it can result in severe hyperinfection syndrome or disseminated strongyloidiasis in immunocompromised patients. There is a great diversity of techniques used in diagnosing the disease, but definitive diagnosis is accomplished by parasitological examination of stool samples for morphological identification of parasite. Until now, no molecular method has been tested in urine samples as an alternative to stool samples for diagnosing strongyloidiasis. This study aimed to evaluate the use of a new molecular LAMP assay in a well-established Wistar rat experimental infection model using both stool and, for the first time, urine samples. The LAMP assay was also clinically evaluated in patients´ stool samples. Stool and urine samples were obtained daily during a 28-day period from rats infected subcutaneously with different infective third-stage larvae doses of S. venezuelensis. The dynamics of parasite infection was determined by daily counting the number of eggs per gram of feces from day 1 to 28 post-infection. A set of primers for LAMP assay based on a DNA partial sequence in the 18S rRNA gene from S. venezuelensis was designed. The set up LAMP assay (namely, Strong-LAMP) allowed the sensitive detection of S. venezuelensis DNA in both stool and urine samples obtained from each infection group of rats and was also effective in S. stercoralis DNA amplification in patients´ stool samples with previously confirmed strongyloidiasis by parasitological and real-time PCR tests. Our Strong-LAMP assay is an useful molecular tool in research of a strongyloidiasis experimental infection model in both stool and urine samples. After further validation, the Strong-LAMP could also be potentially applied for effective diagnosis of strongyloidiasis in a clinical

Trypsin and chymotrypsin in stool

MedlinePlus

... the stool. You can catch the stool on plastic wrap that is loosely placed over the toilet bowl ... child wears a diaper, line the diaper with plastic wrap. Place the plastic wrap so that urine and ...

[Bristol Stool Chart: Prospective and monocentric study of "stools introspection" in healthy subjects].

PubMed

Amarenco, G

2014-09-01

The Bristol Stool Chart (BSC) allows patients to identify their stool form using seven different images with accompanying written descriptors. Stool form was found to correlate better than stool frequency with whole-gut transit as measured by a radio-opaque marker study. This score is widely used in order to verify the presence of a constipation and to evaluate the therapeutic impact of various treatments. In our clinical practice, we was strongly surprised by the facility and the great precision of the patients to report their stool form, meaning that they usually and daily verify these stools. We wanted to precise the goals of a such attitude. Two questionnaires were proposed to healthy and voluntary subjects. Q1 was supposedly presented in order to verify the sensibility of a French version of BSC in a healthy population. Thus, Q1 precised the difficulties or not to understand pictures and written descriptors, asked about exhaustive analysis by means of BSC of stool form and bowel condition. All subjects with history of ano-rectal disorders or specific treatment for bowel dysfunction were excluded. After Q1 fulfilled, Q2 was proposed to the subjects. Q2 was designed to precise the goals of the patient when he look at his stool and the frequency of such an investigation. Finally a specific question concerning the subject opinion about this behavior in terms of bothersome, shame, or metaphysic interrogation. Eighty-five healthy subjects were recruited (42 female and 43 male). Mean age was 37.2 (sd = 15.7). Mean score of BCS was 2.07 (sd =1.05) (2.07 for female and 1.81 for male, P = 0.22). Number of categories of stool form was only 1 in 40%, 2 categories in 31%, 3 in 19%, 4 in 10%. Presence of a constipation defined by category 1 or 2 was found in 17% (23% in F, 12% in M, P = 0.075). Precision of BSC was noted as excellent in 68%, moderated in 18% and poor in 14%. BSC was considered as easy to use in 75%. Frequency of inspection of feces was systematic for 37%, 1

Development of a TaqMan based real-time PCR assay for detection of Clonorchis sinensis DNA in human stool samples and fishes.

PubMed

Cai, Xian-Quan; Yu, Hai-Qiong; Bai, Jian-Shan; Tang, Jian-Dong; Hu, Xu-Chu; Chen, Ding-Hu; Zhang, Ren-Li; Chen, Mu-Xin; Ai, Lin; Zhu, Xing-Quan

2012-03-01

Clonorchiasis caused by the oriental liver fluke Clonorchis sinensis is a fish-borne zoonosis endemic in a number of countries. This article describes the development of a TaqMan based real-time PCR assay for detection of C. sinensis DNA in human feces and in fishes. Primers targeting the first internal transcribed spacer (ITS-1) sequence of the fluke were highly specific for C. sinensis, as evidenced by the negative amplification of closely related trematodes in the test with the exception of Opisthorchis viverrini. The detection limit of the assay was 1pg of purified genomic DNA, 5EPG (eggs per gram feces) or one metacercaria per gram fish filet. The assay was evaluated by testing 22 human fecal samples and 37 fish tissues microscopically determined beforehand, and the PCR results were highly in agreement with the microscopic results. This real-time PCR assay provides a useful tool for the sensitive detection of C. sinensis DNA in human stool and aquatic samples in China and other endemic countries where O. viverrini and Opisthorchis felineus are absent. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Stools - floating

MedlinePlus

... diagnosis. Alternative Names Floating stools Images Lower digestive anatomy References Schiller LR, Sellin JH. Diarrhea. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease . 10th ed. Philadelphia, PA: Elsevier Saunders; 2016: ...

Strong-LAMP: A LAMP Assay for Strongyloides spp. Detection in Stool and Urine Samples. Towards the Diagnosis of Human Strongyloidiasis Starting from a Rodent Model

PubMed Central

Gandasegui, Javier; Bajo Santos, Cristina; López-Abán, Julio; Saugar, José María; Rodríguez, Esperanza; Vicente, Belén; Muro, Antonio

2016-01-01

Background Strongyloides stercoralis, the chief causative agent of human strongyloidiasis, is a nematode globally distributed but mainly endemic in tropical and subtropical regions. Chronic infection is often clinically asymptomatic but it can result in severe hyperinfection syndrome or disseminated strongyloidiasis in immunocompromised patients. There is a great diversity of techniques used in diagnosing the disease, but definitive diagnosis is accomplished by parasitological examination of stool samples for morphological identification of parasite. Until now, no molecular method has been tested in urine samples as an alternative to stool samples for diagnosing strongyloidiasis. This study aimed to evaluate the use of a new molecular LAMP assay in a well-established Wistar rat experimental infection model using both stool and, for the first time, urine samples. The LAMP assay was also clinically evaluated in patients´ stool samples. Methodology/Principal Findings Stool and urine samples were obtained daily during a 28-day period from rats infected subcutaneously with different infective third-stage larvae doses of S. venezuelensis. The dynamics of parasite infection was determined by daily counting the number of eggs per gram of feces from day 1 to 28 post-infection. A set of primers for LAMP assay based on a DNA partial sequence in the 18S rRNA gene from S. venezuelensis was designed. The set up LAMP assay (namely, Strong-LAMP) allowed the sensitive detection of S. venezuelensis DNA in both stool and urine samples obtained from each infection group of rats and was also effective in S. stercoralis DNA amplification in patients´ stool samples with previously confirmed strongyloidiasis by parasitological and real-time PCR tests. Conclusions/Significance Our Strong-LAMP assay is an useful molecular tool in research of a strongyloidiasis experimental infection model in both stool and urine samples. After further validation, the Strong-LAMP could also be potentially

Diagnostic value of stool DNA testing for multiple markers of colorectal cancer and advanced adenoma: a meta-analysis.

PubMed

Yang, Hua; Xia, Bing-Qing; Jiang, Bo; Wang, Guozhen; Yang, Yi-Peng; Chen, Hao; Li, Bing-Sheng; Xu, An-Gao; Huang, Yun-Bo; Wang, Xin-Ying

2013-08-01

The diagnostic value of stool DNA (sDNA) testing for colorectal neoplasms remains controversial. To compensate for the lack of large-scale unbiased population studies, a meta-analysis was performed to evaluate the diagnostic value of sDNA testing for multiple markers of colorectal cancer (CRC) and advanced adenoma. The PubMed, Science Direct, Biosis Review, Cochrane Library and Embase databases were systematically searched in January 2012 without time restriction. Meta-analysis was performed using a random-effects model using sensitivity, specificity, diagnostic OR (DOR), summary ROC curves, area under the curve (AUC), and 95% CIs as effect measures. Heterogeneity was measured using the χ(2) test and Q statistic; subgroup analysis was also conducted. A total of 20 studies comprising 5876 individuals were eligible. There was no heterogeneity for CRC, but adenoma and advanced adenoma harboured considerable heterogeneity influenced by risk classification and various detection markers. Stratification analysis according to risk classification showed that multiple markers had a high DOR for the high-risk subgroups of both CRC (sensitivity 0.759 [95% CI 0.711 to 0.804]; specificity 0.883 [95% CI 0.846 to 0.913]; AUC 0.906) and advanced adenoma (sensitivity 0.683 [95% CI 0.584 to 0.771]; specificity 0.918 [95% CI 0.866 to 0.954]; AUC 0.946) but not for the average-risk subgroups of either. In the methylation subgroup, sDNA testing had significantly higher DOR for CRC (sensitivity 0.753 [95% CI 0.685 to 0.812]; specificity 0.913 [95% CI 0.860 to 0.950]; AUC 0.918) and advanced adenoma (sensitivity 0.623 [95% CI 0.527 to 0.712]; specificity 0.926 [95% CI 0.882 to 0.958]; AUC 0.910) compared with the mutation subgroup. There was no significant heterogeneity among studies for subgroup analysis. sDNA testing for multiple markers had strong diagnostic significance for CRC and advanced adenoma in high-risk subjects. Methylation makers had more diagnostic value than mutation

Stool consistency is strongly associated with gut microbiota richness and composition, enterotypes and bacterial growth rates.

PubMed

Vandeputte, Doris; Falony, Gwen; Vieira-Silva, Sara; Tito, Raul Y; Joossens, Marie; Raes, Jeroen

2016-01-01

The assessment of potentially confounding factors affecting colon microbiota composition is essential to the identification of robust microbiome based disease markers. Here, we investigate the link between gut microbiota variation and stool consistency using Bristol Stool Scale classification, which reflects faecal water content and activity, and is considered a proxy for intestinal colon transit time. Through 16S rDNA Illumina profiling of faecal samples of 53 healthy women, we evaluated associations between microbiome richness, Bacteroidetes:Firmicutes ratio, enterotypes, and genus abundance with self-reported, Bristol Stool Scale-based stool consistency. Each sample's microbiota growth potential was calculated to test whether transit time acts as a selective force on gut bacterial growth rates. Stool consistency strongly correlates with all known major microbiome markers. It is negatively correlated with species richness, positively associated to the Bacteroidetes:Firmicutes ratio, and linked to Akkermansia and Methanobrevibacter abundance. Enterotypes are distinctly distributed over the BSS-scores. Based on the correlations between microbiota growth potential and stool consistency scores within both enterotypes, we hypothesise that accelerated transit contributes to colon ecosystem differentiation. While shorter transit times can be linked to increased abundance of fast growing species in Ruminococcaceae-Bacteroides samples, hinting to a washout avoidance strategy of faster replication, this trend is absent in Prevotella-enterotyped individuals. Within this enterotype adherence to host tissue therefore appears to be a more likely bacterial strategy to cope with washout. The strength of the associations between stool consistency and species richness, enterotypes and community composition emphasises the crucial importance of stool consistency assessment in gut metagenome-wide association studies. Published by the BMJ Publishing Group Limited. For permission to

I. POLIOMYELITIC VIRUS IN HUMAN STOOLS.

PubMed

Trask, J D; Paul, J R; Vignec, A J

1940-05-31

1. The detection of the virus of poliomyelitis in 10 stools from 8 individuals is reported. All were in relation to epidemic poliomyelitis and 7 of them represented well recognized forms of the disease. The positive stools were distributed among 56 specimens collected from 53 persons in the first 4 weeks of illness. 2. The ease of detection of virus was directly related to the non-paralytic type of disease and inversely related to the age of the patients. 3. The negative results with stools employed for controls gives point to the use of the fecal examinations as an epidemiological tool. 4. The stability of the virus in feces has been demonstrated by successful mailing of samples over long distances and during the heat of summer. 5. At least one infective dose per gram of fecal material was extracted from one stool.

Rapid Diagnosis of Diarrhea Caused by Shigella sonnei Using Dipsticks; Comparison of Rectal Swabs, Direct Stool and Stool Culture

PubMed Central

Duran, Claudia; Nato, Faridabano; Dartevelle, Sylvie; Thi Phuong, Lan Nguyen; Taneja, Neelam; Ungeheuer, Marie Noëlle; Soza, Guillermo; Anderson, Leslie; Benadof, Dona; Zamorano, Agustín; Diep, Tai The; Nguyen, Truong Quang; Nguyen, Vu Hoang; Ottone, Catherine; Bégaud, Evelyne; Pahil, Sapna; Prado, Valeria; Sansonetti, Philippe; Germani, Yves

2013-01-01

Background We evaluated a dipstick test for rapid detection of Shigella sonnei on bacterial colonies, directly on stools and from rectal swabs because in actual field situations, most pathologic specimens for diagnosis correspond to stool samples or rectal swabs. Methodology/Principal Findings The test is based on the detection of S. sonnei lipopolysaccharide (LPS) O-side chains using phase I-specific monoclonal antibodies coupled to gold particles, and displayed on a one-step immunochromatographic dipstick. A concentration as low as 5 ng/ml of LPS was detected in distilled water and in reconstituted stools in 6 minutes. This is the optimal time for lecture to avoid errors of interpretation. In distilled water and in reconstituted stools, an unequivocal positive reaction was obtained with 4 x 106 CFU/ml of S. sonnei. The specificity was 100% when tested with a battery of Shigella and different unrelated strains. When tested on 342 rectal swabs in Chile, specificity (281/295) was 95.3% (95% CI: 92.9% - 97.7%) and sensitivity (47/47) was 100%. Stool cultures and the immunochromatographic test showed concordant results in 95.5 % of cases (328/342) in comparative studies. Positive and negative predictive values were 77% (95% CI: 65% - 86.5%) and 100% respectively. When tested on 219 stools in Chile, Vietnam, India and France, specificity (190/198) was 96% (95% CI 92%–98%) and sensitivity (21/21) was 100%. Stool cultures and the immunochromatographic test showed concordant results in 96.3 % of cases (211/219) in comparative studies. Positive and negative predictive values were 72.4% (95% CI 56.1%–88.6%) and 100 %, respectively. Conclusion This one-step dipstick test performed well for diagnosis of S. sonnei both on stools and on rectal swabs. These data confirm a preliminary study done in Chile. PMID:24278267

Real time PCR to detect the environmental faecal contamination by Echinococcus multilocularis from red fox stools.

PubMed

Knapp, Jenny; Millon, Laurence; Mouzon, Lorane; Umhang, Gérald; Raoul, Francis; Ali, Zeinaba Said; Combes, Benoît; Comte, Sébastien; Gbaguidi-Haore, Houssein; Grenouillet, Frédéric; Giraudoux, Patrick

2014-03-17

The oncosphere stage of Echinococcus multilocularis in red fox stools can lead, after ingestion, to the development of alveolar echinococcosis in the intermediate hosts, commonly small mammals and occasionally humans. Monitoring animal infection and environmental contamination is a key issue in public health surveillance. We developed a quantitative real-time PCR technique (qPCR) to detect and quantify E. multilocularis DNA released in fox faeces. A qPCR technique using a hydrolysis probe targeting part of the mitochondrial gene rrnL was assessed on (i) a reference collection of stools from 57 necropsied foxes simultaneously investigated using the segmental sedimentation and counting technique (SSCT) (29 positive for E. multilocularis worms and 28 negative animals for the parasite); (ii) a collection of 114 fox stools sampled in the field: two sets of 50 samples from contrasted endemic regions in France and 14 from an E. multilocularis-free area (Greenland). Of the negative SSCT controls, 26/28 were qPCR-negative and two were weakly positive. Of the positive SSCT foxes, 25/29 samples were found to be positive by qPCR. Of the field samples, qPCR was positive in 21/50 (42%) and 5/48 (10.4%) stools (2 samples inhibited), originating respectively from high and low endemic areas. In faeces, averages of 0.1 pg/μl of DNA in the Jura area and 0.7 pg/μl in the Saône-et-Loire area were detected. All qPCR-positive samples were confirmed by sequencing. The qPCR technique developed here allowed us to quantify environmental E. multilocularis contamination by fox faeces by studying the infectious agent directly. No previous study had performed this test in a one-step reaction. Copyright © 2013 Elsevier B.V. All rights reserved.

Development of a polymerase chain reaction applicable to rapid and sensitive detection of Clonorchis sinensis eggs in human stool samples

PubMed Central

Cho, Pyo Yun; Na, Byoung-Kuk; Mi Choi, Kyung; Kim, Jin Su; Cho, Shin-Hyeong; Lee, Won-Ja; Lim, Sung-Bin; Cha, Seok Ho; Park, Yun-Kyu; Pak, Jhang Ho; Lee, Hyeong-Woo; Hong, Sung-Jong; Kim, Tong-Soo

2013-01-01

Microscopic examination of eggs of parasitic helminths in stool samples has been the most widely used classical diagnostic method for infections, but tiny and low numbers of eggs in stool samples often hamper diagnosis of helminthic infections with classical microscopic examination. Moreover, it is also difficult to differentiate parasite eggs by the classical method, if they have similar morphological characteristics. In this study, we developed a rapid and sensitive polymerase chain reaction (PCR)-based molecular diagnostic method for detection of Clonorchis sinensis eggs in stool samples. Nine primers were designed based on the long-terminal repeat (LTR) of C. sinensis retrotransposon1 (CsRn1) gene, and seven PCR primer sets were paired. Polymerase chain reaction with each primer pair produced specific amplicons for C. sinensis, but not for other trematodes including Metagonimus yokogawai and Paragonimus westermani. Particularly, three primer sets were able to detect 10 C. sinensis eggs and were applicable to amplify specific amplicons from DNA samples purified from stool of C. sinensis-infected patients. This PCR method could be useful for diagnosis of C. sinensis infections in human stool samples with a high level of specificity and sensitivity. PMID:23916334

Multiplex PCR detection of Cryptosporidium sp, Giardia lamblia and Entamoeba histolytica directly from dried stool samples from Guinea-Bissauan children with diarrhoea.

PubMed

Mero, Sointu; Kirveskari, Juha; Antikainen, Jenni; Ursing, Johan; Rombo, Lars; Kofoed, Poul-Erik; Kantele, Anu

2017-09-01

In developing countries, diarrhoea is the most common cause of death for children under five years of age, with Giardia lamblia, Cryptosporidium and Entamoeba histolytica as the most frequent pathogenic parasites. Traditional microscopy for stool parasites has poor sensitivity and specificity, while new molecular methods may provide more accurate diagnostics. In poor regions with sample storage hampered by uncertain electricity supply, research would benefit from a method capable of analysing dried stools. A real-time multiplex PCR method with internal inhibition control was developed for detecting Giardia lamblia, Cryptosporidium hominis/parvum and Entamoeba histolytica directly from stool specimens. Applicability to dried samples was checked by comparing with fresh ones in a small test material. Finally, the assay was applied to dried specimens collected from Guinea-Bissauan children with diarrhoea. The PCR's analytical sensitivity limit was 0.1 ng/ml for G. lamblia DNA, 0.01 ng/ml for E. histolytica DNA and 0.1 ng/ml for Cryptosporidium sp. In the test material, the assay performed similarly with fresh and dried stools. Of the 52 Guinea-Bissauan samples, local microscopy revealed a parasite in 15%, while PCR detected 62% positive for at least one parasite: 44% of the dried samples had Giardia, 23% Cryptosporidium and 0% E. histolytica. Our new multiplex real-time PCR for protozoa presents a sensitive method applicable to dried samples. As proof of concept, it worked well on stools collected from Guinea-Bissauan children with diarrhoea. It provides an epidemiological tool for analysing dried specimens from regions poor in resources.

Stool frequency recording in severe acute malnutrition ('StoolSAM'); an agreement study comparing maternal recall versus direct observation using diapers.

PubMed

Voskuijl, Wieger; Potani, Isabel; Bandsma, Robert; Baan, Anne; White, Sarah; Bourdon, Celine; Kerac, Marko

2017-06-07

Approximately 50% of the deaths of children under the age of 5 can be attributed to undernutrition, which also encompasses severe acute malnutrition (SAM). Diarrhoea is strongly associated with these deaths and is commonly diagnosed solely based on stool frequency and consistency obtained through maternal recall. This trial aims to determine whether this approach is equivalent to a 'directly observed method' in which a health care worker directly observed stool frequency using diapers in hospitalised children with complicated SAM. This study was conducted at 'Moyo' Nutritional Rehabilitation Unit, Queen Elizabeth Central Hospital, Malawi. Participants were children aged 5-59 months admitted with SAM. We compared 2 days of stool frequency data obtained with next-day maternal-recall versus a 'gold standard' in which a health care worker observed stool frequency every 2 h using diapers. After study completion, guardians were asked their preferred method and their level of education. We found poor agreement between maternal recall and the 'gold standard' of directly observed diapers. The sensitivity to detect diarrhoea based on maternal recall was poor, with only 75 and 56% of diarrhoea cases identified on days 1 and 2, respectively. However, the specificity was higher with more than 80% of children correctly classified as not having diarrhoea. On day 1, the mean stool frequency difference between the two methods was -0.17 (SD; 1.68) with limits of agreement (of stool frequency) of -3.55 and 3.20 and, similarly on day 2, the mean difference was -0.2 (SD; 1.59) with limits of agreement of -3.38 and 2.98. These limits extend beyond the pre-specified 'acceptable' limits of agreement (±1.5 stool per day) and indicate that the 2 methods are non-equivalent. The higher the stool frequency, the more discrepant the two methods were. Most primary care givers strongly preferred using diapers. This study shows lack of agreement between the assessment of stool frequency in SAM

Stool guaiac test

MedlinePlus

... guaiac test; gFOBT; Guaiac smear test; Fecal occult blood test - guaiac smear; Stool occult blood test - guaiac smear ... This test detects blood in the digestive tract. It may be done if: You are being screened or tested for colon cancer You ...

Review: Diagnostic accuracy of PCR-based detection tests for Helicobacter Pylori in stool samples.

PubMed

Khadangi, Fatemeh; Yassi, Maryam; Kerachian, Mohammad Amin

2017-12-01

Although different methods have been established to detect Helicobacter pylori (H. pylori) infection, identifying infected patients is an ongoing challenge. The aim of this meta-analysis was to provide pooled diagnostic accuracy measures for stool PCR test in the diagnosis of H. pylori infection. In this study, a systematic review and meta-analysis were carried out on various sources, including MEDLINE, Web of Sciences, and the Cochrane Library from April 1, 1999, to May 1, 2016. This meta-analysis adheres to the guidelines provided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses report (PRISMA Statement). The clinical value of DNA stool PCR test was based on the pooled false positive, false negative, true positive, and true negative of different genes. Twenty-six of 328 studies identified met the eligibility criteria. Stool PCR test had a performance of 71% (95% CI: 68-73) sensitivity, 96% (95% CI: 94-97) specificity, and 65.6 (95% CI: 30.2-142.5) diagnostic odds ratio (DOR) in diagnosis of H. pylori. The DOR of genes which showed the highest performance of stool PCR tests was as follows: 23S rRNA 152.5 (95% CI: 55.5-418.9), 16S rRNA 67.9 (95%CI: 6.4-714.3), and glmM 68.1 (95%CI: 20.1-231.7). The sensitivity and specificity of stool PCR test are relatively in the same spectrum of other diagnostic methods for the detection of H. pylori infection. In descending order of significance, the most diagnostic candidate genes using PCR detection were 23S rRNA, 16S rRNA, and glmM. PCR for 23S rRNA gene which has the highest performance could be applicable to detect H. pylori infection. © 2017 John Wiley & Sons Ltd.

Stool C difficile toxin

MedlinePlus

... toxin; Colitis - toxin; Pseudomembranous - toxin; Necrotizing colitis - toxin; C difficile - toxin ... be analyzed. There are several ways to detect C difficile toxin in the stool sample. Enzyme immunoassay ( ...

DNA extraction and barcode identification of development stages of forensically important flies in the Czech Republic.

PubMed

Olekšáková, Tereza; Žurovcová, Martina; Klimešová, Vanda; Barták, Miroslav; Šuláková, Hana

2018-04-01

Several methods of DNA extraction, coupled with 'DNA barcoding' species identification, were compared using specimens from early developmental stages of forensically important flies from the Calliphoridae and Sarcophagidae families. DNA was extracted at three immature stages - eggs, the first instar larvae, and empty pupal cases (puparia) - using four different extraction methods, namely, one simple 'homemade' extraction buffer protocol and three commercial kits. The extraction conditions, including the amount of proteinase K and incubation times, were optimized. The simple extraction buffer method was successful for half of the eggs and for the first instar larval samples. The DNA Lego Kit and DEP-25 DNA Extraction Kit were useful for DNA extractions from the first instar larvae samples, and the DNA Lego Kit was also successful regarding the extraction from eggs. The QIAamp DNA mini kit was the most effective; the extraction was successful with regard to all sample types - eggs, larvae, and pupari.

Bloody or tarry stools

MedlinePlus

... small intestine Diverticulosis (abnormal pouches in the colon) Hemorrhoids (common cause of bright red blood) Inflammatory bowel ... have an exam even if you think that hemorrhoids are causing the blood in your stool. In ...

First identification of eggs of the Asian fish tapeworm Bothriocephalus acheilognathi (Cestoda: Bothriocephalidea) in human stool.

PubMed

Yera, Hélène; Kuchta, Roman; Brabec, Jan; Peyron, François; Dupouy-Camet, Jean

2013-06-01

We report the first case of egg isolation of the Asian fish tapeworm Bothriocephalus acheilognathi (Bothriocephalidea) from human stool. A male patient from Saint Laurent du Maroni (French Guiana) presenting abdominal pain was examined in France for the diagnosis of intestinal parasites. Diphyllobothrium-like eggs were observed in his stool. However, molecular phylogenetic analyses based on sequences of rDNA and COI genes showed that the eggs observed belong to a bothriocephalidean cestode B. acheilognathi. The adult life stages of B. acheilognathi cestodes are known as invasive parasites of a wide spectrum of fish; however, they have not been described to parasitize any mammals. This human infection seems to be accidental and represents a parasite passage through human intestine after the consumption of an infected fish host. Copyright © 2013. Published by Elsevier Ireland Ltd.

Disposal of children's stools and its association with childhood diarrhea in India.

PubMed

Bawankule, Rahul; Singh, Abhishek; Kumar, Kaushalendra; Pedgaonkar, Sarang

2017-01-05

Children's stool disposal is often overlooked in sanitation programs of any country. Unsafe disposal of children's stool makes children susceptible to many diseases that transmit through faecal-oral route. Therefore, the study aims to examine the magnitude of unsafe disposal of children's stools in India, the factors associated with it and finally its association with childhood diarrhea. Data from the third round of the National Family Health Survey (NFHS-3) conducted in 2005-06 is used to carry out the analysis. The binary logistic regression model is used to examine the factors associated with unsafe disposal of children's stool. Binary logistic regression is also used to examine the association between unsafe disposal of children's stool and childhood diarrhea. Overall, stools of 79% of children in India were disposed of unsafely. The urban-rural gap in the unsafe disposal of children's stool was wide. Mother's illiteracy and lack of exposure to media, the age of the child, religion and caste/tribe of the household head, wealth index, access to toilet facility and urban-rural residence were statistically associated with unsafe disposal of stool. The odds of diarrhea in children whose stools were disposed of unsafely was estimated to be 11% higher (95% CI: 1.01-1.21) than that of children whose stools were disposed of safely. An increase in the unsafe disposal of children's stool in the community also increased the risk of diarrhea in children. We found significant statistical association between children's stool disposal and diarrhea. Therefore, gains in reduction of childhood diarrhea can be achieved in India through the complete elimination of unsafe disposal of children's stools. The sanitation programmes currently being run in India must also focus on safe disposal of children's stool.

A dental stool with chest support reduces lower back muscle activation.

PubMed

Tran, Viet; Turner, Reid; MacFadden, Andrew; Cornish, Stephen M; Esliger, Dale; Komiyama, Kunio; Chilibeck, Philip D

2016-09-01

Activation of back musculature during work tasks leads to fatigue and potential injury. This is especially prevalent in dentists who perform much of their work from a seated position. We examined the use of an ergonomic dental stool with mid-sternum chest support for reducing lower back muscle activation. Electromyography of lower back extensors was assessed from 30 dental students for 20 s during three conditions in random order: (a) sitting upright at 90° of hip flexion on a standard stool, (b) leaning forward at 80° of hip flexion on a standard stool, and (c) leaning forward at 80° of hip flexion while sitting on an ergonomic stool. Muscular activity of the back extensors was reduced when using the ergonomic stool compared to the standard stool, by 33-50% (p < 0.01). This suggests a potential musculoskeletal benefit with use of a dental stool with mid-sternum chest support.

Is "dried stool spots on filter paper method (DSSFP)" more sensitive and effective for detecting Blastocystis spp. and their subtypes by PCR and sequencing?

PubMed

Seyer, Ayse; Karasartova, Djursun; Ruh, Emrah; Güreser, Ayse Semra; Imir, Turgut; Taylan-Ozkan, Aysegul

2016-12-01

PCR and DNA sequencing are currently the diagnostic methods of choice for detection of Blastocystis spp. and their suptypes. Fresh or frozen stool samples have disadvantages in terms of several aspects such as transportation, storage, and existence of PCR inhibitors. Filter paper technology may provide a solution to these issues. The aim of the present study was to detect Blastocystis spp. and their subtypes by employing two different preservation methods: conventional frozen stool (FS) and dried stool spots on filter paper (DSSFP). Concentration and purity of DNA, sensitivity of PCR, and DNA sequencing results obtained from the two methods were also compared. A total of 230 fecal samples were included and separated into two parts: one part of the fecal samples were directly frozen and stored at -20 °C. The remaining portion of the specimens were homogenized with saline and spread onto the filter papers as thin layer with a diameter of approximately 3 cm. After air-dried, the filter papers were stored at room temperature. DSSFP samples were collected by scraping from the filter papers. DNA were extracted by EURx Stool DNA Extraction Kit from both samples. Concentration and purity were measured with Nano-Drop, then PCR and sequencing were conducted for detection of Blastocystis spp. and its genotypes. Pure DNA was obtained with a A260/A280 ratio of 1.7-2.2 in both methods. DNA yield from FS was 25-405 ng/μl and average DNA concentration was 151 ng/μl, while these were 7-339 and 122 ng/μl for DSSFP, respectively. No PCR inhibition was observed in two methods. DNA from DSSFP were found to be stable and PCR were reproducible for at least 1 year. FS-PCR- and DSSFP-PCR-positive samples were 49 (21.3 %) and 58 (25.3 %), respectively (p = 0.078). The 43 specimens were concordantly positive by both FS-PCR and DSSFP-PCR. When the microscopy was taken as the gold standard, sensitivity of DSSFP-PCR and FS-PCR was 95.5 and 86.4 %, while specificity of both

Validation of a modified Bristol stool scale - inter-rater reliability amongst pediatric gastroenterologists

USDA-ARS?s Scientific Manuscript database

Stool form and changes in stool form are important criteria in both clinical practice and clinical research. However, descriptions of stool form from both patients and physicians alike may be subjective and objective measurements of stool form are not well developed. Although the Bristol stool scale...

Assessment of commonly used pediatric stool scales: a pilot study.

PubMed

Saps, M; Nichols-Vinueza, D; Dhroove, G; Adams, P; Chogle, A

2013-01-01

The Bristol Stool Form Scale (BSFS) and a modified child-friendly version (M-BSFS) are frequently used in clinical practice and research. These scales have not been validated in children. 3-D stool scale models may be better adapted to the child's development. To assess the usefulness of the BSFS, M-BSFS, and a newly developed 3-D stool scale in children. Fifty children were asked to rank the picture cards of the BSFS and 3-D models from hardest to softest and to match the pictures with descriptors for each stool type. Thirty percent of the children appropriately characterized the stools as hard, loose, or normal using the BSFS vs. 36.6% with the 3-D model (p=0.27). Appropriate correlation of stools as hard, loose, or normal consistency using the BSFS vs. the 3-D model by age group was: 6 to 11-year-olds, 27.5% vs. 33.3% (p=0.58) and 12 to 17-year-olds, 32.1% vs. 39.5% (p=0.41). Thirty-three percent correlated the BSFS pictures with the correct BSFS words, 46% appropriately correlated with the M-BSFS words, and 46% correlated the 3-D stool models with the correct wording. The BSFS and M-BSFS that are widely used as stool assessment instruments are not user-friendly for children. The 3-D model was not found to be better than the BSFS and the M-BSFS. Copyright © 2013 Asociación Mexicana de Gastroenterología. Published by Masson Doyma México S.A. All rights reserved.

Stool fatty acid soaps, stool consistency and gastrointestinal tolerance in term infants fed infant formulas containing high sn-2 palmitate with or without oligofructose: a double-blind, randomized clinical trial.

PubMed

Nowacki, Joyce; Lee, Hung-Chang; Lien, Reyin; Cheng, Shao-Wen; Li, Sung-Tse; Yao, Manjiang; Northington, Robert; Jan, Ingrid; Mutungi, Gisella

2014-11-05

Formula-fed (FF) infants often have harder stools and higher stool concentrations of fatty acid soaps compared to breastfed infants. Feeding high sn-2 palmitate or the prebiotic oligofructose (OF) may soften stools, reduce stool soaps, and decrease fecal calcium loss. We investigated the effect of high sn-2 palmitate alone and in combination with OF on stool palmitate soap, total soap and calcium concentrations, stool consistency, gastrointestinal (GI) tolerance, anthropometrics, and hydration in FF infants. This double-blind trial randomized 165 healthy term infants 25-45 days old to receive Control formula (n = 54), formula containing high sn-2 palmitate (sn-2; n = 56), or formula containing high sn-2 palmitate plus 3 g/L OF (sn-2+OF; n = 55). A non-randomized human milk (HM)-fed group was also included (n = 55). The primary endpoint, stool composition, was determined after 28 days of feeding, and was assessed using ANOVA accompanied by pairwise comparisons. Stool consistency, GI tolerance and hydration were assessed at baseline, day 14 (GI tolerance only) and day 28. Infants fed sn-2 had lower stool palmitate soaps compared to Control (P = 0.0028); while those fed sn-2+OF had reduced stool palmitate soaps compared to both Control and sn-2 (both P < 0.0001). Stool total soaps and calcium were lower in the sn-2+OF group than either Control (P < 0.0001) or sn-2 (P < 0.0001). The HM-fed group had lower stool palmitate soaps, total soaps and calcium (P < 0.0001 for each comparison) than all FF groups. The stool consistency score of the sn-2+OF group was lower than Control and sn-2 (P < 0.0001), but higher than the HM-fed group (P < 0.0001). GI tolerance was similar and anthropometric z-scores were <0.2 SD from the WHO growth standards in all groups, while urinary hydration markers were within normal range for all FF infants. Increasing sn-2 palmitate in infant formula reduces stool palmitate soaps. A combination of high sn-2 palmitate and OF reduces

Culturing Stool Specimens for Campylobacter spp., Pennsylvania, USA

PubMed Central

M’ikanatha, Nkuchia M.; Dettinger, Lisa A.; Perry, Amanda; Rogers, Paul; Reynolds, Stanley M.

2012-01-01

In 2010, we surveyed 176 clinical laboratories in Pennsylvania regarding stool specimen testing practices for enteropathogens, including Campylobacter spp. Most (96.3%) routinely test for Campylobacter spp. In 17 (15.7%), a stool antigen test is the sole method for diagnosis. We recommend that laboratory practice guidelines for Campylobacter spp. testing be developed. PMID:22377086

Evaluation of four automated protocols for extraction of DNA from FTA cards.

PubMed

Stangegaard, Michael; Børsting, Claus; Ferrero-Miliani, Laura; Frank-Hansen, Rune; Poulsen, Lena; Hansen, Anders J; Morling, Niels

2013-10-01

Extraction of DNA using magnetic bead-based techniques on automated DNA extraction instruments provides a fast, reliable, and reproducible method for DNA extraction from various matrices. Here, we have compared the yield and quality of DNA extracted from FTA cards using four automated extraction protocols on three different instruments. The extraction processes were repeated up to six times with the same pieces of FTA cards. The sample material on the FTA cards was either blood or buccal cells. With the QIAamp DNA Investigator and QIAsymphony DNA Investigator kits, it was possible to extract DNA from the FTA cards in all six rounds of extractions in sufficient amount and quality to obtain complete short tandem repeat (STR) profiles on a QIAcube and a QIAsymphony SP. With the PrepFiler Express kit, almost all the extractable DNA was extracted in the first two rounds of extractions. Furthermore, we demonstrated that it was possible to successfully extract sufficient DNA for STR profiling from previously processed FTA card pieces that had been stored at 4 °C for up to 1 year. This showed that rare or precious FTA card samples may be saved for future analyses even though some DNA was already extracted from the FTA cards.

Optimal screening and donor management in a public stool bank.

PubMed

Kazerouni, Abbas; Burgess, James; Burns, Laura J; Wein, Lawrence M

2015-12-17

Fecal microbiota transplantation is an effective treatment for recurrent Clostridium difficile infection and is being investigated as a treatment for other microbiota-associated diseases. To facilitate these activities, an international public stool bank has been created, which screens donors and processes stools in a standardized manner. The goal of this research is to use mathematical modeling and analysis to optimize screening and donor management at the stool bank. Compared to the current policy of screening active donors every 60 days before releasing their quarantined stools for sale, costs can be reduced by 10.3 % by increasing the screening frequency to every 36 days. In addition, the stool production rate varies widely across donors, and using donor-specific screening, where higher producers are screened more frequently, also reduces costs, as does introducing an interim (i.e., between consecutive regular tests) stool test for just rotavirus and C. difficile. We also derive a donor release (i.e., into the system) policy that allows the supply to approximately match an exponentially increasing deterministic demand. More frequent screening, interim screening for rotavirus and C. difficile, and donor-specific screening, where higher stool producers are screened more frequently, are all cost-reducing measures. If screening costs decrease in the future (e.g., as a result of bringing screening in house), a bottleneck for implementing some of these recommendations may be the reluctance of donors to undergo serum screening more frequently than monthly.

Flushable reagent stool blood test

MedlinePlus

Stool occult blood test - flushable home test; Fecal occult blood test - flushable home test ... This test is performed at home with disposable pads. You can buy the pads at the drug store without ...

Performance characteristics and comparison of Abbott and artus real-time systems for hepatitis B virus DNA quantification.

PubMed

Ismail, Ashrafali M; Sivakumar, Jayashree; Anantharam, Raghavendran; Dayalan, Sujitha; Samuel, Prasanna; Fletcher, Gnanadurai J; Gnanamony, Manu; Abraham, Priya

2011-09-01

Virological monitoring of hepatitis B virus (HBV) DNA is critical to the management of HBV infection. With several HBV DNA quantification assays available, it is important to use the most efficient testing system for virological monitoring. In this study, we evaluated the performance characteristics and comparability of three HBV DNA quantification systems: Abbott HBV real-time PCR (Abbott PCR), artus HBV real-time PCR with QIAamp DNA blood kit purification (artus-DB), and artus HBV real-time PCR with the QIAamp DSP virus kit purification (artus-DSP). The lower limits of detection of these systems were established against the WHO international standards for HBV DNA and were found to be 1.43, 82, and 9 IU/ml, respectively. The intra-assay and interassay coefficients of variation of plasma samples (1 to 6 log(10) IU/ml) ranged between 0.05 to 8.34% and 0.16 to 3.48% for the Abbott PCR, 1.53 to 26.85% and 0.50 to 12.89% for artus-DB, and 0.29 to 7.42% and 0.94 to 3.01% for artus-DSP, respectively. Ninety HBV clinical samples were used for comparison of assays, and paired quantitative results showed strong correlation by linear regression analysis (artus-DB with Abbott PCR, r = 0.95; Abbott PCR with artus-DSP, r = 0.97; and artus-DSP with artus-DB, r = 0.94). Bland-Altman analysis showed a good level of agreement for Abbott PCR and artus-DSP, with a mean difference of 0.10 log(10) IU/ml and limits of agreement of -0.91 to 1.11 log(10) IU/ml. No genotype-specific bias was seen in all three systems for HBV genotypes A, C, and D, which are predominant in this region. This finding illustrates that the Abbott real-time HBV and artus-DSP systems show more comparable performance than the artus-DB system, meeting the current guidelines for assays to be used in the management of hepatitis B.

DNA Methylation and Mutation of Small Colonic Neoplasms in Ulcerative Colitis and Crohn's Colitis: Implications for Surveillance.

PubMed

Johnson, David H; Taylor, William R; Aboelsoud, Mohammed M; Foote, Patrick H; Yab, Tracy C; Cao, Xiaoming; Smyrk, Thomas C; Loftus, Edward V; Mahoney, Douglas W; Ahlquist, David A; Kisiel, John B

2016-07-01

Stool DNA testing in patients with inflammatory bowel disease (IBD) may detect colorectal cancer and advanced precancers with high sensitivity; less is known about the presence of DNA markers in small IBD lesions, their association with metachronous neoplasia, or contribution to stool test positivity. At a single center in 2 blinded phases, we assayed methylated bone morphogenic protein 3, methylated N-Myc downstream-regulated gene 4, and mutant KRAS in DNA extracted from paraffin-embedded benign lesions, and matched control tissues of patients with IBD, who were followed for subsequent colorectal dysplasia. Stool samples from independent cases and controls with lesions <1 cm or advanced neoplasms were assayed for the same markers. Among IBD lesions (29 low-grade dysplasia, 19 serrated epithelial change, and 10 sessile serrated adenoma/polyps), the prevalence of methylation was significantly higher than in mucosae from 44 matched IBD controls (P < 0.0001 for methylated bone morphogenic protein 3 or methylated N-Myc downstream-regulated gene 4). KRAS mutations were more abundant in serrated epithelial change than all other groups (P < 0.001). Subsequent dysplasia was not associated with DNA marker levels. In stools, the sensitivity of methylated bone morphogenic protein 3 as a single marker was 60% for all lesions <1 cm, 63% for low-grade dysplasia ≥1 cm and 81% for high-grade dysplasia/colorectal cancer, all at 91% specificity (P < 0.0001). Selected DNA markers known to be present in advanced IBD neoplasia can also be detected in both tissues and stools from IBD patients with small adenomas and serrated lesions. Mutant KRAS exfoliated from serrated epithelial change lesions might raise false-positive rates. These findings have relevance to potential future applications of stool DNA testing for IBD surveillance.

Performance Characteristics and Comparison of Abbott and artus Real-Time Systems for Hepatitis B Virus DNA Quantification ▿

PubMed Central

Ismail, Ashrafali M.; Sivakumar, Jayashree; Anantharam, Raghavendran; Dayalan, Sujitha; Samuel, Prasanna; Fletcher, Gnanadurai J.; Gnanamony, Manu; Abraham, Priya

2011-01-01

Virological monitoring of hepatitis B virus (HBV) DNA is critical to the management of HBV infection. With several HBV DNA quantification assays available, it is important to use the most efficient testing system for virological monitoring. In this study, we evaluated the performance characteristics and comparability of three HBV DNA quantification systems: Abbott HBV real-time PCR (Abbott PCR), artus HBV real-time PCR with QIAamp DNA blood kit purification (artus-DB), and artus HBV real-time PCR with the QIAamp DSP virus kit purification (artus-DSP). The lower limits of detection of these systems were established against the WHO international standards for HBV DNA and were found to be 1.43, 82, and 9 IU/ml, respectively. The intra-assay and interassay coefficients of variation of plasma samples (1 to 6 log10 IU/ml) ranged between 0.05 to 8.34% and 0.16 to 3.48% for the Abbott PCR, 1.53 to 26.85% and 0.50 to 12.89% for artus-DB, and 0.29 to 7.42% and 0.94 to 3.01% for artus-DSP, respectively. Ninety HBV clinical samples were used for comparison of assays, and paired quantitative results showed strong correlation by linear regression analysis (artus-DB with Abbott PCR, r = 0.95; Abbott PCR with artus-DSP, r = 0.97; and artus-DSP with artus-DB, r = 0.94). Bland-Altman analysis showed a good level of agreement for Abbott PCR and artus-DSP, with a mean difference of 0.10 log10 IU/ml and limits of agreement of −0.91 to 1.11 log10 IU/ml. No genotype-specific bias was seen in all three systems for HBV genotypes A, C, and D, which are predominant in this region. This finding illustrates that the Abbott real-time HBV and artus-DSP systems show more comparable performance than the artus-DB system, meeting the current guidelines for assays to be used in the management of hepatitis B. PMID:21795507

[When should a stool culture be done in adults with nosocomial diarrhea?].

PubMed

Mathieu, Alexandre; Tachet, Anne; Pariente, Alexandre

2005-01-29

To assess the diagnostic efficacy, cost and possible corrective measure of the indications for routine stool cultures in nosocomial diarrhoea in adults. A retrospective study over a 10-month period of 660 standard stool cultures, 256 of which were conducted after the 3rd day of hospitalisation, conducted in 528 patients at the hospital centre in Pau. The positivity rate of the stool cultures was of 26/336 patients (7.7%), and of 37/404 examinations (9%) within the first three days of hospitalisation, versus 2/192 patients (1%) and 3/256 examinations (1%) after the 3rd day of hospitalisation (p<0.05). In 83 patients a stool culture was repeated, and was only positive in one patient with an initially negative culture. If a stool culture had not been performed after the 3rd day, 2 infections would not have been diagnosed (1 salmonella and 1 K. oxytoca) and 256 stool cultures could have been economised (estimated cost: 6,144 euro). Moreover, by eliminating repeated stool cultures, 3 infections would not have been diagnosed (2 salmonella, and 1 K. oxytoca) and 321 stool cultures would have been avoided (estimated cost: 7,704 euro). If the stool cultures had been conducted after the 3rd day of hospitalisation only in those aged over 64 with comorbidity, immunosuppression or within the context of an epidemic, no false negative would have been observed and 149 stool cultures would have been economised (estimated cost: 3,576 euro). The positivity rate of the search for C. difficile, only conducted on explicit request from the practitioners, was of 5/23 (22%) and 4/28 (14%) before and after the 3rd day of hospitalisation (non-significant difference). Restriction of standard stool cultures after the 3rd day of hospitalisation to patients aged over 64 with comorbidity, to the immunodepressed, and within an epidemic context would economise around 4,300 euro per month in a medium-sized general hospital. No systematic restriction should be applied to the search for C. difficile.

Optimization of circulating cell-free DNA recovery for KRAS mutation and HPV detection in plasma.

PubMed

Mazurek, Agnieszka M; Fiszer-Kierzkowska, A; Rutkowski, T; Składowski, K; Pierzyna, M; Scieglińska, D; Woźniak, G; Głowacki, G; Kawczyński, R; Małusecka, E

2013-01-01

The precise analysis of tumour markers in blood such as circulating cell-free DNA (cfDNA) could have a significant impact in facilitating monitoring of patients after initial therapy. Although high levels of total cfDNA in plasma of cancer patients are consistently demonstrated, a low sensitivity of DNA alterations is reported. The major question regards the recovery of tumour-specific cfDNA such as KRAS mutated DNA and cancer-associated type 16 of human papillomavirus (HPV16). TaqMan technology was used for detection of KRAS mutation, HPV16 and to quantify cfDNA in blood plasma. Comparison of four different column-based commercial kits shows that the cfDNA purification carried out by the Genomic Mini AX Body Fluids kit and the QIAamp Circulating Nucleic Acid kit gave us the possibility to improve the sensitivity of detection of KRAS mutation and HPV16. The optimized method was used to follow the reduction in cancer-specific cfDNA after therapy. We found that large volume extractions with low volume of DNA eluate enabled trace amounts of tumour-specific cfDNA from cancer patients to be effectively identified. Data presented in this study facilitate detection of tumour-specific cfDNA and improve standards needed for the implementation of cfDNA technology into routine clinical practice.

Undigested Pills in Stool Mimicking Parasitic Infection.

PubMed

Mir, Fazia; Achakzai, Ilyas; Ibdah, Jamal A; Tahan, Veysel

2017-01-01

Background . Orally ingested medications now come in both immediate release and controlled release preparations. Controlled release preparations were developed by pharmaceutical companies to improve compliance and decrease frequency of pill ingestion. Case Report . A 67-year-old obese male patient presented to our clinic with focal abdominal pain that had been present 3 inches below umbilicus for the last three years. This pain was not associated with any trauma or recent heavy lifting. Upon presentation, the patient reported that for the last two months he started to notice pearly oval structures in his stool accompanying his chronic abdominal pain. This had coincided with initiation of his nifedipine pills for his hypertension. He reported seeing these undigested pills daily in his stool. Conclusion . The undigested pills may pose a cause of concern for both patients and physicians alike, as demonstrated in this case report, because they can mimic a parasitic infection. This can result in unnecessary extensive work-up. It is important to review the medication list for extended release formulations and note that the outer shell can be excreted whole in the stool.

Comparison of ELISA and Microscopy for detection of Cryptosporidium in stool

PubMed Central

Sharma, Madhu; Chaudhary, Uma; Yadav, Aparna

2014-01-01

Background: Cryptosporidiosis, a diarrheal disease caused by the protozoan parasite Cryptosporidium spp. has become recognized as one of the most common causes of water borne diseases in humans. Aims and Objectives: To compare the sensitivity of ELISA and Microscopy for detection of Cryptosporidium in stool samples Materials and Methods: The study was conducted in the Department of Microbiology of PT. B.D. Sharma PGIMS Rohtak, between January 2011 to june 2011 on 50 stool samples, which were processed for detection of cryptosporidial antigen by ELISA and detection of cysts by microscopy (Modified Ziehl and Nelsen staining). Study and Design: This was a prospective study conducted in the Department of Microbiology in PT. BD Sharma, PGIMS, Rohtak, India. Result: Out of total, 50 stool samples eighteen (36%) samples were found positive for Cryptosporidium cysts by microscopy in comparison to 3(6%) stool samples which were found positive for cryptosporidial antigen by ELISA. Samples found positive with ELISA were also positive with microscopy. Sensitivity, specificity, positive predictive value and negative predictive value for ELISA was 16.7%, 100%, 100% and 68% respectively. Conclusion: The study concludes that stool microscopic Modified acid fast staining is more sensitive method than ELISA for detection of Cryptosporidium in stool samples but the specificity of ELISA was more than microscopy. PMID:25584216

Comparison of five methods for extraction of Legionella pneumophila from respiratory specimens.

PubMed

Wilson, Deborah; Yen-Lieberman, Belinda; Reischl, Udo; Warshawsky, Ilka; Procop, Gary W

2004-12-01

The efficiencies of five commercially available nucleic acid extraction methods were evaluated for the recovery of a standardized inoculum of Legionella pneumophila in respiratory specimens (sputum and bronchoalveolar lavage [BAL] specimens). The concentrations of Legionella DNA recovered from sputa with the automated MagNA Pure (526,200 CFU/ml) and NucliSens (171,800 CFU/ml) extractors were greater than those recovered with the manual methods (i.e., Roche High Pure kit [133,900 CFU/ml], QIAamp DNA Mini kit [46,380 CFU/ml], and ViralXpress kit [13,635 CFU/ml]). The rank order was the same for extracts from BAL specimens, except that for this specimen type the QIAamp DNA Mini kit recovered more than the Roche High Pure kit.

Evaluation and optimization of microbial DNA extraction from fecal samples of wild Antarctic bird species

PubMed Central

Eriksson, Per; Mourkas, Evangelos; González-Acuna, Daniel; Olsen, Björn; Ellström, Patrik

2017-01-01

ABSTRACT Introduction: Advances in the development of nucleic acid-based methods have dramatically facilitated studies of host–microbial interactions. Fecal DNA analysis can provide information about the host’s microbiota and gastrointestinal pathogen burden. Numerous studies have been conducted in mammals, yet birds are less well studied. Avian fecal DNA extraction has proved challenging, partly due to the mixture of fecal and urinary excretions and the deficiency of optimized protocols. This study presents an evaluation of the performance in avian fecal DNA extraction of six commercial kits from different bird species, focusing on penguins. Material and methods: Six DNA extraction kits were first tested according to the manufacturers’ instructions using mallard feces. The kit giving the highest DNA yield was selected for further optimization and evaluation using Antarctic bird feces. Results: Penguin feces constitute a challenging sample type: most of the DNA extraction kits failed to yield acceptable amounts of DNA. The QIAamp cador Pathogen kit (Qiagen) performed the best in the initial investigation. Further optimization of the protocol resulted in good yields of high-quality DNA from seven bird species of different avian orders. Conclusion: This study presents an optimized approach to DNA extraction from challenging avian fecal samples. PMID:29152162

Evaluating the Impact of DNA Extraction Method on the Representation of Human Oral Bacterial and Fungal Communities

PubMed Central

Biswas, Kristi; Taylor, Michael W.; Gear, Kim

2017-01-01

The application of high-throughput, next-generation sequencing technologies has greatly improved our understanding of the human oral microbiome. While deciphering this diverse microbial community using such approaches is more accurate than traditional culture-based methods, experimental bias introduced during critical steps such as DNA extraction may compromise the results obtained. Here, we systematically evaluate four commonly used microbial DNA extraction methods (MoBio PowerSoil® DNA Isolation Kit, QIAamp® DNA Mini Kit, Zymo Bacterial/Fungal DNA Mini PrepTM, phenol:chloroform-based DNA isolation) based on the following criteria: DNA quality and yield, and microbial community structure based on Illumina amplicon sequencing of the V3–V4 region of the 16S rRNA gene of bacteria and the internal transcribed spacer (ITS) 1 region of fungi. Our results indicate that DNA quality and yield varied significantly with DNA extraction method. Representation of bacterial genera in plaque and saliva samples did not significantly differ across DNA extraction methods and DNA extraction method showed no effect on the recovery of fungal genera from plaque. By contrast, fungal diversity from saliva was affected by DNA extraction method, suggesting that not all protocols are suitable to study the salivary mycobiome. PMID:28099455

Early Detection of Neonatal Cholestasis: Inadequate Assessment of Stool Color by Parents and Primary Healthcare Doctors.

PubMed

Witt, Mauri; Lindeboom, Jeanet; Wijnja, Corry; Kesler, Anneke; Keyzer-Dekker, Claudia M G; Verkade, Henkjan J; Hulscher, Jan B F

2016-02-01

Early diagnosis and surgery (< 60 days of age) improve outcomes in children with biliary atresia. Only 56% of patients undergo timely surgery in the Netherlands. Lack of acquaintance with symptoms such as discolored stools might underlie this delay. We analyzed whether Dutch parents, youth healthcare doctors, or general practitioners recognized discolored stools and evaluated the effect of the Infant Stool Color Card (ISCC) on recognizing discolored stools. We asked 100 parents, 33 youth healthcare doctors, and 50 general practitioners to classify photographs of stools as "normal" or "abnormal." Subsequently, we asked whether parents would seek medical help and doctors would refer the patient for medical investigation. Finally, parents scored stools using the ISCC. Two-third of both parents and youth healthcare doctors recognized all discolored stools. Only half of them would seek medical help for all discolored stools resp. refer patient for medical investigation. Only one-third of the general practitioners recognized all discolored stools and would refer for medical investigation for all discolored stools. Using the ISCC, the percentage of parents recognizing all discolored stool increased from 66 to 87% (p < 0.01). Neither parents nor youth healthcare doctors nor general practitioners reliably recognize discolored stool. The ISCC is an effective screening method for discolored stool. Our data indicate that the ISCC should be accompanied by unequivocal advices regarding referral for medical investigation upon detection of discolored stools. Georg Thieme Verlag KG Stuttgart · New York.

Typeability of DNA in Touch Traces Deposited on Paper and Optical Data Discs.

PubMed

Sołtyszewski, Ireneusz; Szeremeta, Michał; Skawrońska, Małgorzata; Niemcunowicz-Janica, Anna; Pepiński, Witold

2015-01-01

Nucleated epithelial cells that are transferred by casual touching and handling of objects are the primary source of biological evidence that is found in high-volume crimes. Cellular material associated with touch traces usually contains low levels of DNA template making it challenging to acquire an informative profile. The main purpose of this study was to examine the efficacy of DNA typing in fingerprints deposited on optical data discs and the office paper. Latent fingerprints were made by 60 subjects of both sexes (30 males and 30 females). A highly effective DNA extraction method with QIAamp DNA Mini Kit (Qiagen) and an increased sensitivity PCR by AmpFlSTR® NGM™ Amplification Kit (Applied Biosystems) carried out at standard 30 cycles and at increased 34 cycles were used. The mean value of total DNA recovery was 0.4 ng from CDs/DVDs and 0.3 ng from the office paper. Amplification of Low Template DNA (LT-DNA) resulted in improved analytical success by increasing the number of PCR cycles from standard 30 to 34. On the other hand, the increased PCR cycles resulted in allele drop-ins showing additional peaks, the majority of which were outside the stutter positions. Rigorous procedures and interpretation guidelines are required during LT-DNA for producing reliable and reproducible DNA profiles for forensic purposes.

Shared and Distinct Features of Human Milk and Infant Stool Viromes

PubMed Central

Pannaraj, Pia S.; Ly, Melissa; Cerini, Chiara; Saavedra, Monica; Aldrovandi, Grace M.; Saboory, Abdul A.; Johnson, Kevin M.; Pride, David T.

2018-01-01

Infants acquire many of their microbes from their mothers during the birth process. The acquisition of these microbes is believed to be critical in the development of the infant immune system. Bacteria also are transmitted to the infant through breastfeeding, and help to form the microbiome of the infant gastrointestinal (GI) tract; it is unknown whether viruses in human milk serve to establish an infant GI virome. We examined the virome contents of milk and infant stool in a cohort of mother-infant pairs to discern whether milk viruses colonize the infant GI tract. We observed greater viral alpha diversity in milk than in infant stool, similar to the trend we found for bacterial communities from both sites. When comparing beta diversity, viral communities were mostly distinguishable between milk and infant stool, but each was quite distinct from adult stool, urine, and salivary viromes. There were significant differences in viral families in the infant stool (abundant bacteriophages from the family Siphoviridae) compared to milk (abundant bacteriophages from the family Myoviridae), which may reflect significant differences in the bacterial families identified from both sites. Despite the differences in viral taxonomy, we identified a significant number of shared viruses in the milk and stool from all mother-infant pairs. Because of the significant proportion of bacteriophages transmitted in these mother-infant pairs, we believe the transmission of milk phages to the infant GI tract may help to shape the infant GI microbiome. PMID:29910789

Stool Microbiome and Metabolome Differences between Colorectal Cancer Patients and Healthy Adults

PubMed Central

Weir, Tiffany L.; Manter, Daniel K.; Sheflin, Amy M.; Barnett, Brittany A.; Heuberger, Adam L.; Ryan, Elizabeth P.

2013-01-01

In this study we used stool profiling to identify intestinal bacteria and metabolites that are differentially represented in humans with colorectal cancer (CRC) compared to healthy controls to identify how microbial functions may influence CRC development. Stool samples were collected from healthy adults (n = 10) and colorectal cancer patients (n = 11) prior to colon resection surgery at the University of Colorado Health-Poudre Valley Hospital in Fort Collins, CO. The V4 region of the 16s rRNA gene was pyrosequenced and both short chain fatty acids and global stool metabolites were extracted and analyzed utilizing Gas Chromatography-Mass Spectrometry (GC-MS). There were no significant differences in the overall microbial community structure associated with the disease state, but several bacterial genera, particularly butyrate-producing species, were under-represented in the CRC samples, while a mucin-degrading species, Akkermansia muciniphila, was about 4-fold higher in CRC (p<0.01). Proportionately higher amounts of butyrate were seen in stool of healthy individuals while relative concentrations of acetate were higher in stools of CRC patients. GC-MS profiling revealed higher concentrations of amino acids in stool samples from CRC patients and higher poly and monounsaturated fatty acids and ursodeoxycholic acid, a conjugated bile acid in stool samples from healthy adults (p<0.01). Correlative analysis between the combined datasets revealed some potential relationships between stool metabolites and certain bacterial species. These associations could provide insight into microbial functions occurring in a cancer environment and will help direct future mechanistic studies. Using integrated “omics” approaches may prove a useful tool in identifying functional groups of gastrointestinal bacteria and their associated metabolites as novel therapeutic and chemopreventive targets. PMID:23940645

Recombinase Polymerase Amplification-Based Assay to Diagnose Giardia in Stool Samples

PubMed Central

Crannell, Zachary Austin; Cabada, Miguel Mauricio; Castellanos-Gonzalez, Alejandro; Irani, Ayesha; White, Arthur Clinton; Richards-Kortum, Rebecca

2015-01-01

Giardia duodenalis is one of the most commonly identified parasites in stool samples. Although relatively easy to treat, giardiasis can be difficult to detect as it presents similar to other diarrheal diseases. Here, we present a recombinase polymerase amplification-based Giardia (RPAG) assay to detect the presence of Giardia in stool samples. The RPAG assay was characterized on the bench top using stool samples spiked with Giardia cysts where it showed a limit-of-detection nearly as low as the gold standard polymerase chain reaction assay. The RPAG assay was then tested in the highlands of Peru on 104 stool samples collected from the surrounding communities where it showed 73% sensitivity and 95% specificity against a polymerase chain reaction and microscopy composite gold standard. Further improvements in clinical sensitivity will be needed for the RPAG assay to have clinical relevance. PMID:25510713

Fetal exposures and perinatal influences on the stool microbiota of premature infants.

PubMed

Chernikova, Diana A; Koestler, Devin C; Hoen, Anne Gatewood; Housman, Molly L; Hibberd, Patricia L; Moore, Jason H; Morrison, Hilary G; Sogin, Mitchell L; Zain-Ul-Abideen, Muhammad; Madan, Juliette C

2016-01-01

To test the hypothesis that maternal complications significantly affect gut colonization patterns in very low birth weight infants. Forty-nine serial stool samples were obtained weekly from nine extremely premature infants enrolled in a prospective longitudinal study. Sequencing of the bacterial 16S rRNA gene from stool samples was performed to approximate the intestinal microbiome. Linear mixed effects models were used to evaluate relationships between perinatal complications and intestinal microbiome development. Subjects with prenatal exposure to a non-sterile intrauterine environment, i.e. prolonged preterm premature rupture of membranes (PPPROM) and chorioamnionitis exposure, were found to have a relatively higher abundance of potentially pathogenic bacteria in the stool across all time points compared to subjects without those exposures, irrespective of exposure to postnatal antibiotics. Compared with those delivered by Caesarean section, vaginally delivered subjects were found to have significantly lower diversity of stool microbiota across all time points, with lower abundance of many genera, most in the family Enterobacteriaceae. We identified persistently increased potential pathogen abundance in the developing stool microbiota of subjects exposed to a non-sterile uterine environment. Maternal complications appear to significantly influence the diversity and bacterial composition of the stool microbiota of premature infants, with findings persisting over time.

Fetal exposures and perinatal influences on the stool microbiota of premature infants

PubMed Central

Chernikova, Diana A.; Koestler, Devin C.; Hoen, Anne Gatewood; Housman, Molly L.; Hibberd, Patricia L.; Moore, Jason H.; Morrison, Hilary G.; Sogin, Mitchell L.; Ul-Abideen, Muhammad Zain; Madan, Juliette C.

2015-01-01

Objective To test the hypothesis that maternal complications significantly affect gut colonization patterns in very low birth weight infants. Methods 49 serial stool samples were obtained weekly from 9 extremely premature infants enrolled in a prospective longitudinal study. Sequencing of the bacterial 16S rRNA gene from stool samples was performed to approximate the intestinal microbiome. Linear mixed effects models were used to evaluate relationships between perinatal complications and intestinal microbiome development. Results Subjects with prenatal exposure to a non-sterile intrauterine environment, i.e. PPPROM and chorioamnionitis exposure, were found to have a relatively higher abundance of potentially pathogenic bacteria in the stool across all time points compared to subjects without those exposures, irrespective of exposure to postnatal antibiotics. Compared with those delivered by Caesarean section, vaginally delivered subjects were found to have significantly lower diversity of stool microbiota across all time points, with lower abundance of many genera, most in the family Enterobacteriaceae. Conclusions We identified persistently increased potential pathogen abundance in the developing stool microbiota of subjects exposed to a non-sterile uterine environment. Maternal complications appear to significantly influence the diversity and bacterial composition of the stool microbiota of premature infants, with findings persisting over time. PMID:25394613

Comparative evaluation of in-house manual, and commercial semi-automated and automated DNA extraction platforms in the sample preparation of human stool specimens for a Salmonella enterica 5'-nuclease assay.

PubMed

Schuurman, Tim; de Boer, Richard; Patty, Rachèl; Kooistra-Smid, Mirjam; van Zwet, Anton

2007-12-01

In the present study, three methods (NucliSens miniMAG [bioMérieux], MagNA Pure DNA Isolation Kit III Bacteria/Fungi [Roche], and a silica-guanidiniumthiocyanate {Si-GuSCN-F} procedure for extracting DNA from stool specimens were compared with regard to analytical performance (relative DNA recovery and down stream real-time PCR amplification of Salmonella enterica DNA), stability of the extracted DNA, hands-on time (HOT), total processing time (TPT), and costs. The Si-GuSCN-F procedure showed the highest analytical performance (relative recovery of 99%, S. enterica real-time PCR sensitivity of 91%) at the lowest associated costs per extraction (euro 4.28). However, this method did required the longest HOT (144 min) and subsequent TPT (176 min) when processing 24 extractions. Both miniMAG and MagNA Pure extraction showed similar performances at first (relative recoveries of 57% and 52%, S. enterica real-time PCR sensitivity of 85%). However, when difference in the observed Ct values after real-time PCR were taken into account, MagNA Pure resulted in a significant increase in Ct value compared to both miniMAG and Si-GuSCN-F (with on average +1.26 and +1.43 cycles). With regard to inhibition all methods showed relatively low inhibition rates (< 4%), with miniMAG providing the lowest rate (0.7%). Extracted DNA was stable for at least 1 year for all methods. HOT was lowest for MagNA Pure (60 min) and TPT was shortest for miniMAG (121 min). Costs, finally, were euro 4.28 for Si-GuSCN, euro 6.69 for MagNA Pure and euro 9.57 for miniMAG.

Detection and sequencing of rotavirus among sudanese children.

PubMed

Magzoub, Magzoub Abbas; Bilal, Naser Eldin; Bilal, Jalal Ali; Alzohairy, Mohammad Abdulrahman; Elamin, Bahaeldin Khalid; Gasim, Gasim Ibrahim

2017-01-01

Diarrheal diseases are a big public health problem worldwide, particularly among developing countries. The current study was conducted to detect and characterize group A rotavirus among admitted children with gastroenteritis to the pediatric hospitals, Sudan. A total of 755 stool samples were collected from Sudanese children with less than 5 years of age presenting with acute gastroenteritis during the period from April to September 2010. Enzyme-linked immunosorbent assay (ELISA) was used to Detection of Rotavirus antigens. Ribonucleic acid (RNAs) were extracted from rotavirus-positive stool samples using (QIAamp ® Viral RNA Mini Kit). (Omniscript ® Reverse Transcription kit) was used to convert RNA to complementary Deoxyribonucleic acid (cDNA). The cDNAs were used as template for detection of VP4-P (P for Protease-sensitive) and VP7-G (G for Glycoprotein) genotyping of Rotavirus using nested PCR and sequencing. Out of the 755 stool samples from children with acute gastroenteritis, 121 were positive for rotavirus A. Among 24 samples that were sequenced; the VP7 predominant G type was G1 (83.3%), followed by G9 (16.7%). Out of these samples, only one VP4 P[8] genotype was detected. As a conclusion the VP7 predominant G type was G1, followed by G9 whereas only one VP4 genotype was detected and showed similarity to P[8] GenBank strain. It appears that the recently approved rotavirus vaccines in Sudan are well matched to the rotavirus genotypes identified in this study, though more studies are needed.

Multiplex Real-Time PCR Method for Simultaneous Identification and Toxigenic Type Characterization of Clostridium difficile From Stool Samples

PubMed Central

Alam, Mohammad J.; Tisdel, Naradah L.; Shah, Dhara N.; Yapar, Mehmet; Lasco, Todd M.; Garey, Kevin W.

2015-01-01

Background The aim of this study was to develop and validate a multiplex real-time PCR assay for simultaneous identification and toxigenic type characterization of Clostridium difficile. Methods The multiplex real-time PCR assay targeted and simultaneously detected triose phosphate isomerase (tpi) and binary toxin (cdtA) genes, and toxin A (tcdA) and B (tcdB) genes in the first and sec tubes, respectively. The results of multiplex real-time PCR were compared to those of the BD GeneOhm Cdiff assay, targeting the tcdB gene alone. The toxigenic culture was used as the reference, where toxin genes were detected by multiplex real-time PCR. Results A total of 351 stool samples from consecutive patients were included in the study. Fifty-five stool samples (15.6%) were determined to be positive for the presence of C. difficile by using multiplex real-time PCR. Of these, 48 (87.2%) were toxigenic (46 tcdA and tcdB-positive, two positive for only tcdB) and 11 (22.9%) were cdtA-positive. The sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of the multiplex real-time PCR compared with the toxigenic culture were 95.6%, 98.6%, 91.6%, and 99.3%, respectively. The analytical sensitivity of the multiplex real-time PCR assay was determined to be 103colonyforming unit (CFU)/g spiked stool sample and 0.0625 pg genomic DNA from culture. Analytical specificity determined by using 15 enteric and non-clostridial reference strains was 100%. Conclusions The multiplex real-time PCR assay accurately detected C. difficile isolates from diarrheal stool samples and characterized its toxin genes in a single PCR run. PMID:25932438

PoopMD, a Mobile Health Application, Accurately Identifies Infant Acholic Stools.

PubMed

Franciscovich, Amy; Vaidya, Dhananjay; Doyle, Joe; Bolinger, Josh; Capdevila, Montserrat; Rice, Marcus; Hancock, Leslie; Mahr, Tanya; Mogul, Douglas B

2015-01-01

Biliary atresia (BA) is the leading cause of pediatric end-stage liver disease in the United States. Education of parents in the perinatal period with stool cards depicting acholic and normal stools has been associated with improved time-to-diagnosis and survival in BA. PoopMD is a mobile application that utilizes a smartphone's camera and color recognition software to analyze an infant's stool and determine if additional follow-up is indicated. PoopMD was developed using custom HTML5/CSS3 and wrapped to work on iOS and Android platforms. In order to define the gold standard regarding stool color, seven pediatricians were asked to review 45 photographs of infant stool and rate them as acholic, normal, or indeterminate. Samples for which 6+ pediatricians demonstrated agreement defined the gold standard, and only these samples were included in the analysis. Accuracy of PoopMD was assessed using an iPhone 5s with incandescent lighting. Variability in analysis of stool photographs as acholic versus normal with intermediate rating weighted as 50% agreement (kappa) was compared between three laypeople and one expert user. Variability in output was also assessed between an iPhone 5s and a Samsung Galaxy S4, as well as between incandescent lighting and compact fluorescent lighting. Six-plus pediatricians agreed on 27 normal and 7 acholic photographs; no photographs were defined as indeterminate. The sensitivity was 7/7 (100%). The specificity was 24/27 (89%) with 3/27 labeled as indeterminate; no photos of normal stool were labeled as acholic. The Laplace-smoothed positive likelihood ratio was 6.44 (95% CI 2.52 to 16.48) and the negative likelihood ratio was 0.13 (95% CI 0.02 to 0.83). kappauser was 0.68, kappaphone was 0.88, and kappalight was 0.81. Therefore, in this pilot study, PoopMD accurately differentiates acholic from normal color with substantial agreement across users, and almost perfect agreement across two popular smartphones and ambient light settings. Poop

Recombinase polymerase amplification-based assay to diagnose Giardia in stool samples.

PubMed

Crannell, Zachary Austin; Cabada, Miguel Mauricio; Castellanos-Gonzalez, Alejandro; Irani, Ayesha; White, Arthur Clinton; Richards-Kortum, Rebecca

2015-03-01

Giardia duodenalis is one of the most commonly identified parasites in stool samples. Although relatively easy to treat, giardiasis can be difficult to detect as it presents similar to other diarrheal diseases. Here, we present a recombinase polymerase amplification-based Giardia (RPAG) assay to detect the presence of Giardia in stool samples. The RPAG assay was characterized on the bench top using stool samples spiked with Giardia cysts where it showed a limit-of-detection nearly as low as the gold standard polymerase chain reaction assay. The RPAG assay was then tested in the highlands of Peru on 104 stool samples collected from the surrounding communities where it showed 73% sensitivity and 95% specificity against a polymerase chain reaction and microscopy composite gold standard. Further improvements in clinical sensitivity will be needed for the RPAG assay to have clinical relevance. © The American Society of Tropical Medicine and Hygiene.

Diagnostic Yield of Routine Enteropathogenic Stool Tests in Pediatric Ulcerative Colitis.

PubMed

Ihekweazu, Faith D; Ajjarapu, Avanthi; Kellermayer, Richard

2015-01-01

It can be important to exclude infectious etiologies prior to adjusting immunosuppressive therapy in patients with ulcerative colitis (UC) exacerbation. We sought to determine the diagnostic yield of routine infectious stool studies in pediatric UC patients. We conducted a retrospective review of 152 pediatric UC patients at Texas Children's Hospital between January 2003 and December 2009. The patient records were followed through July 2014. The number and type of infectious stool studies performed and the results of those were collected. Three hundred fifty-four diagnostic stool tests were conducted for Clostridium difficile; 13.6% were positive. Two hundred twenty stool bacterial cultures were performed, and 1.8% were positive, all growing non-typhoid Salmonella. One of 13 (7.7%) Adenovirus PCR tests was positive. Two of 152 examinations (1.3%) for Ova and Parasites were positive. No stool tests for viral culture, viral particles, Yersinia or Rotavirus were positive. Clostridium difficile infection is common in pediatric UC, and routine screening during flares is strongly recommended. Other bacterial and parasitic infections routinely tested for are uncommon, but Salmonella may be a potentially important attribute to disease exacerbations in select patients. In patients without co-morbid conditions, the utility of performing non-specific fecal viral tests is questionable. © 2015 by the Association of Clinical Scientists, Inc.

First detection and genotyping of Giardia intestinalis in stool samples collected from children in Ghazni Province, eastern Afghanistan and evaluation of the PCR assay in formalin-fixed specimens.

PubMed

Lass, Anna; Karanis, Panagiotis; Korzeniewski, Krzysztof

2017-08-01

It is estimated that faecal-orally transmitted diseases are common in Afghanistan, as a consequence of poor hygienic standards of life and widespread contamination of water and food with both human and animal faeces. However, there is little information in the literature concerning infections caused by intestinal parasites in the Afghan population. In this study, we report the occurrence of Giardia intestinalis assemblages (A and B) in formalin-fixed stool samples collected from 245 Afghan schoolchildren living in Ghazni Province in eastern Afghanistan. Detection of the parasite's DNA and genotyping was performed using real-time PCR, specific to the β-giardin gene of G. intestinalis. Positive results were recorded in 52 (21.2%) samples. Genotyping was successful in 39 faecal samples and showed the predominance of assemblage B of G. intestinalis in this population (15 assemblage A and 24 assemblage B). Co-infection with both genotypes A and B was detected in four samples. Additionally, we evaluated the effect of 10% buffered formalin fixative on the detection of G. intestinalis DNA using real-time PCR and nested PCR characterised by different lengths of PCR products (74 and 479 bp, respectively). The human faeces containing the Giardia cysts were tested for 16 weeks. Amplification of G. intestinalis DNA with real-time PCR was possible up to 6 weeks of preservation of stool sample in formalin, compared to only 2 weeks with nested PCR. This suggests that real-time PCR is a more suitable tool in cases where stool samples have to be kept in formalin for longer periods of time.

IBS Patients Show Frequent Fluctuations between Loose/Watery and Hard/Lumpy Stools: Implications for Treatment

PubMed Central

Palsson, Olafur S.; Baggish, Jeffrey S.; Turner, Marsha J.; Whitehead, William E.

2013-01-01

Aims To determine how variable stool consistency is in patients with irritable bowel (IBS) and assess the relationship between stool consistency and gastrointestinal symptoms. Methods Individuals with a physician diagnosis of IBS were recruited by advertisement. Enrollment questionnaires included the Rome III Diagnostic Questionnaire and IBS Symptom Severity Scale. Then 185 patients meeting Rome criteria for IBS rated the consistency (using the Bristol Stool Scale) of each bowel movement (BM) for 90 days and whether the BM was accompanied by pain, urgency, or soiling. Each night they transferred BM ratings from a paper diary to an internet form and also reported the average daily intensity of abdominal pain, bloating, bowel habit dissatisfaction, and life interference of bowel symptoms. Only the longest sequence of consecutive days of diary data was used in analysis (average of 73 days). Results Patients were 89% female with average age 36.6 years. 78% had both loose/watery and hard/lumpy stools; the average was 3 fluctuations between these extremes per month. The proportion of loose/watery stools correlated r=.78 between the first and second months and the proportion of hard/lumpy stools correlated r=.85 between months. Loose/watery stools were associated with more BM-related pain, urgency, and soiling than hard/lumpy or normal stools; however, IBS-C patients had significantly more BM-unrelated abdominal pain, bloating, dissatisfaction with bowel habits, and life interference than IBS-D. Questionnaires overestimated the frequency of abnormal stool consistency and gastrointestinal symptoms compared to diaries. Conclusions Stool consistency varies greatly within individuals. However, stool patterns are stable within an individual from month to month. The paradoxical findings of greater symptom severity after individual loose/watery BMs vs. greater overall symptom severity in IBS-C implies different physiological mechanisms for symptoms in constipation compared to

DNA sequences and proteic antigens of H. pylori in cholecystic bile and tissue of patients with gallstones.

PubMed

Neri, V; Margiotta, M; de Francesco, V; Ambrosi, A; Valle, N Della; Fersini, A; Tartaglia, N; Minenna, M F; Ricciardelli, C; Giorgio, F; Panella, C; Ierardi, E

2005-10-15

Although Helicobacter pylori DNA sequences have been detected in cholecystic bile and tissue of patients with gallstones, controversial results are reported from different geographic areas. To detect H. pylori in cholecystic bile and tissue of patients with gallstones from a previously uninvestigated geographic area, southern Italy. Detection included both the bacterial DNA and the specific antigen (H. pylori stool antigen) identified in the stools of infected patients for diagnostic purposes. The study enclosed 33 consecutive patients undergoing laparoscopic cholecystectomy for gallstones. DNA sequences of H. pylori were detected by polymerase chain reaction in both cholecystic bile and tissue homogenate. Moreover, we assayed H.pylori stool antigen on gall-bladder cytosolic and biliary proteins after their extraction. Bacterial presence in the stomach was assessed by urea breath test in all patients and Deltadelta13CPDB value assumed as marker of intragastric load. Fisher's exact probability and Student's t-tests were used for statistical analysis. DNA sequences of H. pylori in bile were found in 51.5% and significantly correlated with its presence in cholecystic tissue homogenate (P<0.005), H. pylori stool antigen in gall-bladder (P=0.0013) and bile (P=0.04) proteins, gastric infection (P<0.01) and intragastric bacterial load (P<0.001). No correlation was found, however, with sex and age of the patients. Our prevalence value of bacterial DNA in bile and gall-bladder of patients with gallstones agreed with that of the only other Italian study. The simultaneous presence of both bacterial DNA and proteic antigen suggests that the same prototype of bacterium could be located at both intestinal and cholecystic level and, therefore, the intestine represents the source of biliary contagion.

Stool microbiome and metabolome differences between colorectal cancer patients and healthy adults

USDA-ARS?s Scientific Manuscript database

In this study we used stool profiling to identify intestinal bacteria and metabolites that are differentially represented in humans with colorectal cancer (CRC) compared to healthy controls to identify how microbial functions may influence CRC development. Stool samples were collected from healthy a...

An iPhone application using a novel stool color detection algorithm for biliary atresia screening.

PubMed

Hoshino, Eri; Hayashi, Kuniyoshi; Suzuki, Mitsuyoshi; Obatake, Masayuki; Urayama, Kevin Y; Nakano, Satoshi; Taura, Yasuyuki; Nio, Masaki; Takahashi, Osamu

2017-10-01

The stool color card has been the primary tool for identifying acholic stools in infants with biliary atresia (BA), in several countries. However, BA stools are not always acholic, as obliteration of the bile duct occurs gradually. This study aims to introduce Baby Poop (Baby unchi in Japanese), a free iPhone application, employing a detection algorithm to capture subtle differences in colors, even with non-acholic BA stools. The application is designed for use by caregivers of infants aged approximately 2 weeks-1 month. Baseline analysis to determine optimal color parameters predicting BA stools was performed using logistic regression (n = 50). Pattern recognition and machine learning processes were performed using 30 BA and 34 non-BA images. Additional 5 BA and 35 non-BA pictures were used to test accuracy. Hue, saturation, and value (HSV) were the preferred parameter for BA stool identification. A sensitivity and specificity were 100% (95% confidence interval 0.48-1.00 and 0.90-1.00, respectively) even among a collection of visually non-acholic, i.e., pigmented BA stools and relatively pale-colored non-BA stools. Results suggest that an iPhone mobile application integrated with a detection algorithm is an effective and convenient modality for early detection of BA, and potentially for other related diseases.

Modification of stool's water content in constipated infants: management with an adapted infant formula

PubMed Central

2011-01-01

Background Constipation is a common occurrence in formula-fed infants. The aim of this preliminary study was to evaluate the impact of a formula with high levels of lactose and magnesium, in compliance with the official regulations, on stool water content, as well as a parental assessment of constipation. Materials and methods Thirty healthy term-born, formula-fed infants, aged 4-10 weeks, with functional constipation were included. All infants were full-term and fed standard formula. Exclusion criteria were preterm and/or low birth weight, organic constipation, being breast fed or fed a formula specially designed to treat constipation. Stool composition was measured by near-infrared reflectance analysis (NIRA) and parents answered questions about crying associated with defecation and stool consistency at baseline and after two weeks of the adapted formula. Results After 2 weeks of the adapted formula, stool water content increased from 71 +/- 8.1% to 84 +/- 5.9%, (p < 0.02). There was no significant change in the stool's fat, protein or carbohydrate content. Parental impressions of constipation were improved with the decrease in stool hardness (100% with hard stools at baseline, 10% after 2 weeks), pain with defecation (90% at baseline, 10% after 2 weeks), and the requirement for rectal stimulation to achieve defecation (70% at baseline, 30% after 2 weeks, p < 0.001 for all three indicators). Conclusions This preliminary study suggests that an adapted formula with high levels of lactose and magnesium increases stool water content and improves symptoms of constipation in term-born, formula-fed infants. A larger randomized placebo-controlled trial is indicated. PMID:21595890

Differences in gut microbiota associated with age, sex, and stool consistency in healthy Japanese subjects.

PubMed

Takagi, Tomohisa; Naito, Yuji; Inoue, Ryo; Kashiwagi, Saori; Uchiyama, Kazuhiko; Mizushima, Katsura; Tsuchiya, Saeko; Dohi, Osamu; Yoshida, Naohisa; Kamada, Kazuhiro; Ishikawa, Takeshi; Handa, Osamu; Konishi, Hideyuki; Okuda, Kayo; Tsujimoto, Yoshimasa; Ohnogi, Hiromu; Itoh, Yoshito

2018-06-20

Human gut microbiota is involved in host health and disease development. Investigations of age-related and sex-related alterations in gut microbiota are limited, and the association between stool consistency and gut microbiota has not been fully investigated. We investigated gut microbiota differences related to age, sex, and stool consistency in healthy Japanese subjects. Two-hundred and seventy-seven healthy Japanese subjects aged 20-89 years were enrolled. Fecal samples were obtained to analyze the gut microbiome. We evaluated the association between stool consistency [Bristol stool scale (BSS)] and gut microbiota. Although there were significant differences in the microbial structure between males and females, the α-diversity of gut microbiota showed no difference between males and females or among age groups. There were significant increases in genera Prevotella, Megamonas, Fusobacterium, and Megasphaera and Bifidobacterium, Ruminococcus, and Akkermansia in males and females, respectively. The ratio of hard stools (BSS types 1 and 2) was higher in females; the ratio of loose stools (BSS type 6) was higher in males. No younger male had BSS type 1 or type 2. Fusobacterium in males was significantly higher in the loose consistency group, and Oscillospira was significantly higher in the hard consistency group in males; Campylobacter, SMB53, and Turicibacter were significantly higher in the hard consistency group in females. Several changes in gut microbiota were associated with age and sex. Stool consistency and gut microbiota associations emphasized the importance of stool consistency assessments to understand intestinal function.

Stool submission by general practitioners in SW England - when, why and how? A qualitative study.

PubMed

McNulty, Cliodna A M; Lasseter, Gemma; Newby, Katie; Joshi, Puja; Yoxall, Harry; Kumaran, Kalyanaraman; O'Brien, Sarah J; Evans, Mark

2012-08-08

We know little about when and why general practitioners (GPs) submit stool specimens in patients with diarrhoea. The recent UK-wide intestinal infectious disease (IID2) study found ten GP consultations for every case reported to national surveillance. We aimed to explore what factors influence GP's decisions to send stool specimens for laboratory investigation, and what guidance, if any, informs them. We used qualitative methods that enabled us to explore opinions and ask open questions through 20 telephone interviews with GPs with a range of stool submission rates in England, and a discussion group with 24 GPs. Interviews were transcribed and subjected to content analysis. Interviews: GPs only sent stool specimens to microbiology if diarrhoea persisted for over one week, after recent travel, or the patient was very unwell. Very few had a systematic approach to determine the clinical or public health need for a stool specimen. Only two GPs specifically asked patients about blood in their stool; only half asked about recent antibiotics, or potential food poisoning, and few asked about patients' occupations. Few GPs gave patients advice on how to collect specimens.Results from interviews and discussion group in relation to guidance: All reported that the HPA stool guidance and patient collection instructions would be useful in their clinical work, but only one GP (an interviewee) had previously accessed them. The majority of GPs would value links to guidance on electronic requests. Most GPs were surprised that a negative stool report did not exclude all the common causes of IID. GPs value stool culture and laboratories should continue to provide it. Patient instructions on how to collect stool specimens should be within stool collection kits. Through readily accessible guidance and education, GPs need to be encouraged to develop a more systematic approach to eliciting and recording details in the patient's history that indicate greater risk of severe infection or

Stool consistency and stool frequency are excellent clinical markers for adequate colon preparation after polyethylene glycol 3350 cleansing protocol: a prospective clinical study in children.

PubMed

Safder, Shaista; Demintieva, Yulia; Rewalt, Mary; Elitsur, Yoram

2008-12-01

Colon preparation for a colonoscopy in children is a difficult task because of the unpalatable taste and large volume of cleansing solution that needs to be consumed to ensure a clean colon. Consequently, an unprepared colon frequently occurs in routine practices, which causes early termination and a repeated procedure. (1) To assess the effectiveness of polyethylene glycol solution (PEG 3350) in preparing the colon of children scheduled for a colonoscopy and (2) to investigate clinical markers associated with an adequate colon preparation before a colonoscopy. A total of 167 children scheduled for a colonoscopy. In a prospective study, children scheduled for a colonoscopy were given PEG 3350 solution (1.5 g/kg per day, up to 100 g/d) over a 4-day preparation period. Each day, a simple questionnaire that documents the amount of liquid consumed, adverse effects, and the number and consistency of stool was completed by the parents. After a colonoscopy procedure, the colon preparation was assigned a number grade. The data were later assessed and were compared to determine the association between the grade of cleansing and the frequency and/or consistency of stool during preparation. Colon preparation was completed in 149 children, 133 of whom were adequately prepared. Inadequate preparation was found in 16 children; the procedure was terminated prematurely in 2 of these patients because of unacceptable conditions. No significant adverse effects were noted. A number of >or=5 stools/d, and liquid stool consistency in the last 2 days of preparation were associated with adequate colon preparation. PEG 3350 solution is safe, efficacious, and tolerable for children. Stool frequency and consistency in the last 2 days of preparation were excellent markers (positive predictive value 91%-95%), which predict an adequately clean colon before a colonoscopy in children.

Stool color card screening for biliary atresia.

PubMed

Tseng, Jui-Ju; Lai, Mei-Su; Lin, Ming-Chih; Fu, Yun-Ching

2011-11-01

Biliary atresia is a major cause of extrahepatic obstructive jaundice in neonates. Early Kasai operation is the gold standard of treatment. In this study, we evaluated the effectiveness of stool color card screening by using claims data from the National Health Insurance Research Database. This was a retrospective cohort study. Data from medical charts of all inpatients who were diagnosed with biliary atresia from 1996 to 2008 were collected from Taiwan's National Health Insurance Research Database. Patients who received a Kasai operation or liver transplant were identified by the Operation code. The patients' gender, age at admission, and type of operation were collected and analyzed. From 1996 to 2008, the overall incidence of biliary atresia was 1.48 per 10,000 live births. The median age at first admission for patients with suspected biliary atresia decreased after the implementation of stool color card screening (47 vs 43 days). The proportion of very late referral decreased from 9.5% to 4.9%. The median age of Kasai operation advanced from 51 to 48 days. The proportions of Kasai operation within 60 days of age were 68.9% before and 73.6% after screening program. Stool color card screening seemed to increase parents' and physicians' awareness of biliary atresia. It also was associated with a decline in the proportion of late referral. Thus, screening might be especially effective in areas with high a proportion of late referral. Improvements in the speed of workup and the operation room should be the focus of education and training in the future.

Reaction mechanism of Ru(II) piano-stool complexes: umbrella sampling QM/MM MD study.

PubMed

Futera, Zdeněk; Burda, Jaroslav V

2014-07-15

Biologically relevant interactions of piano-stool ruthenium(II) complexes with ds-DNA are studied in this article by hybrid quantum mechanics-molecular mechanics (QM/MM) computational technique. The whole reaction mechanism is divided into three phases: (i) hydration of the [Ru(II) (η(6) -benzene)(en)Cl](+) complex, (ii) monoadduct formation between the resulting aqua-Ru(II) complex and N7 position of one of the guanines in the ds-DNA oligomer, and (iii) formation of the intrastrand Ru(II) bridge (cross-link) between two adjacent guanines. Free energy profiles of all the reactions are explored by QM/MM MD umbrella sampling approach where the Ru(II) complex and two guanines represent a quantum core, which is described by density functional theory methods. The combined QM/MM scheme is realized by our own software, which was developed to couple several quantum chemical programs (in this study Gaussian 09) and Amber 11 package. Calculated free energy barriers of the both ruthenium hydration and Ru(II)-N7(G) DNA binding process are in good agreement with experimentally measured rate constants. Then, this method was used to study the possibility of cross-link formation. One feasible pathway leading to Ru(II) guanine-guanine cross-link with synchronous releasing of the benzene ligand is predicted. The cross-linking is an exergonic process with the energy barrier lower than for the monoadduct reaction of Ru(II) complex with ds-DNA. Copyright © 2014 Wiley Periodicals, Inc.

Detection of Helicobacter pylori by Real-Time PCR for 16s rRNA in Stools of NonInfected Healthy Children, Using ELISA Antigen Stool Test as the Gold Standard.

PubMed

George, Sergio; Mamani, Nora; Lucero, Yalda; Torres, Juan Pablo; Farfán, Mauricio; Lagomarcino, Anne J; Orellana, Andrea; O'Ryan, Miguel

2016-12-01

We previously detected Helicobacter pylori infection by stool antigen ELISA assay in 33-41% of asymptomatic Chilean children between 2-3 years of age, of which 11-20% had a transient infection and 21-22% a persistent infection. A total of 88% of ELISA-positive samples were also rtPCR positive, while 37/133 (33%) of ELISA-negative stool samples were rtPCR positive. The significance of a ELISA-negative/rtPCR-positive sample requires clarification. We aimed to determine whether rtPCR is able to detect persistent infections not detected by ELISA. We selected 36 children with an ELISA-negative/rtPCR-positive stool sample, of which 25 were never H. pylori infected according to ELISA, and 11 had a transient infection with an ELISA-positive sample before or after the discordant sample. At least two additional consecutive ELISA-negative samples per child were tested in duplicate by rtPCR for the 16s rRNA gene. A total of 14 of 78 (17.9%) rtPCR reactions were positive, but only 4/78 (5.1%) were positive in both duplicates, representing a total of 3/36 (8.3%) children with an additional rtPCR-positive sample, only one of whom was persistently negative by ELISA. One child with a transient infection had two positive rtPCR reactions despite negative ELISA samples. In H. pylori noninfected or transiently infected children, as determined by stool ELISA, additional ELISA-negative/rtPCR-positive stool samples were found in 8.3% of children, but a possible persistent infection was only identified in 2.7% of children. Thus, the characterization of infection dynamics in children is not being misrepresented by application of stool ELISA. Furthermore, rtPCR does not significantly improve dynamic characterization. © 2016 John Wiley & Sons Ltd.

LUMINEX®: a new technology for the simultaneous identification of five Entamoeba spp. commonly found in human stools

PubMed Central

2013-01-01

Background Six species of the genus Entamoeba, i.e., E. histolytica, E. dispar, E. moshkovskii, E. polecki, E. coli, and E. hartmanii can be found in human stools. Among these, only E. histolytica is considered to be pathogenic, causing intestinal and extra-intestinal disease, but it is morphologically identical to E. dispar and E. moshkovskii. In general, E. polecki, E. coli, and E. hartmanii can be differentiated morphologically from E. histolytica, but some of their diagnostic morphologic features may overlap creating issues for the differential diagnosis. Moreover, the previous inability to differentiate among Entamoeba species has limited epidemiologic information on E histolytica. The objective of this study was to develop a rapid, high-throughput screening method using Luminex technique for the simultaneous detection and differentiation of Entamoeba species. Methods PCR amplification was performed with biotinylated Entamoeba sp 18S rRNA gene primers, designed to amplify a fragment ranging from 382 to 429 bp of the Entamoeba spp studied. Regions of this fragment that could differentiate among E. histolytica, E. moshkovskii, E. dispar, E. hartmanii and E. coli were selected to design hybridization probes to link to Luminex beads. The assay was standardized with cloned DNA samples of each species and evaluated with 24 DNA extracts from samples obtained from individuals diagnosed with these amebas in their stools. Results Using this approach we were able to correctly identify E. histoltyica, E. dispar, E hartmanni, E. coli and E. moshkovskii in all specimens studied. From twenty four samples tested by microscopy, PCR/DNA Sequencing and real-time PCR, 100% agreed with PCR-Luminex assay for identification of E. dispar, E. moshkovskii, E. hartmanni, E. histolytica, and E. coli. Conclusion These results show that this method could be used in the diagnostic detection of Entamoeba spp in fecal samples. This diagnostic test was useful to clearly distinguish E

LUMINEX®: a new technology for the simultaneous identification of five Entamoeba spp. commonly found in human stools.

PubMed

Santos, Helena Lúcia Carneiro; Bandyopadhyay, Kakali; Bandea, Rebecca; Peralta, Regina Helena Saramago; Peralta, José Mauro; Da Silva, Alexandre Januário

2013-03-15

Six species of the genus Entamoeba, i.e., E. histolytica, E. dispar, E. moshkovskii, E. polecki, E. coli, and E. hartmanii can be found in human stools. Among these, only E. histolytica is considered to be pathogenic, causing intestinal and extra-intestinal disease, but it is morphologically identical to E. dispar and E. moshkovskii. In general, E. polecki, E. coli, and E. hartmanii can be differentiated morphologically from E. histolytica, but some of their diagnostic morphologic features may overlap creating issues for the differential diagnosis. Moreover, the previous inability to differentiate among Entamoeba species has limited epidemiologic information on E histolytica. The objective of this study was to develop a rapid, high-throughput screening method using Luminex technique for the simultaneous detection and differentiation of Entamoeba species. PCR amplification was performed with biotinylated Entamoeba sp 18S rRNA gene primers, designed to amplify a fragment ranging from 382 to 429 bp of the Entamoeba spp studied. Regions of this fragment that could differentiate among E. histolytica, E. moshkovskii, E. dispar, E. hartmanii and E. coli were selected to design hybridization probes to link to Luminex beads. The assay was standardized with cloned DNA samples of each species and evaluated with 24 DNA extracts from samples obtained from individuals diagnosed with these amebas in their stools. Using this approach we were able to correctly identify E. histoltyica, E. dispar, E hartmanni, E. coli and E. moshkovskii in all specimens studied. From twenty four samples tested by microscopy, PCR/DNA Sequencing and real-time PCR, 100% agreed with PCR-Luminex assay for identification of E. dispar, E. moshkovskii, E. hartmanni, E. histolytica, and E. coli. These results show that this method could be used in the diagnostic detection of Entamoeba spp in fecal samples. This diagnostic test was useful to clearly distinguish E histolytica from other species and also to

Detection of Gastrointestinal Pathogens from Stool Samples on Hemoccult Cards by Multiplex PCR

PubMed Central

Schlenker, Nicklas; Bauer, Malkin; Helfrich, Kerstin; Mengele, Carolin; Löscher, Thomas; Nothdurft, Hans Dieter; Bretzel, Gisela; Beissner, Marcus

2017-01-01

Purpose. Up to 30% of international travelers are affected by travelers' diarrhea (TD). Reliable data on the etiology of TD is lacking. Sufficient laboratory capacity at travel destinations is often unavailable and transporting conventional stool samples to the home country is inconvenient. We evaluated the use of Hemoccult cards for stool sampling combined with a multiplex PCR for the detection of model viral, bacterial, and protozoal TD pathogens. Methods. Following the creation of serial dilutions for each model pathogen, last positive dilution steps (LPDs) and thereof calculated last positive sample concentrations (LPCs) were compared between conventional stool samples and card samples. Furthermore, card samples were tested after a prolonged time interval simulating storage during a travel duration of up to 6 weeks. Results. The LPDs/LPCs were comparable to testing of conventional stool samples. After storage on Hemoccult cards, the recovery rate was 97.6% for C. jejuni, 100% for E. histolytica, 97.6% for norovirus GI, and 100% for GII. Detection of expected pathogens was possible at weekly intervals up to 42 days. Conclusion. Stool samples on Hemoccult cards stored at room temperature can be used in combination with a multiplex PCR as a reliable tool for testing of TD pathogens. PMID:28408937

Detection of Gastrointestinal Pathogens from Stool Samples on Hemoccult Cards by Multiplex PCR.

PubMed

Alberer, Martin; Schlenker, Nicklas; Bauer, Malkin; Helfrich, Kerstin; Mengele, Carolin; Löscher, Thomas; Nothdurft, Hans Dieter; Bretzel, Gisela; Beissner, Marcus

2017-01-01

Purpose . Up to 30% of international travelers are affected by travelers' diarrhea (TD). Reliable data on the etiology of TD is lacking. Sufficient laboratory capacity at travel destinations is often unavailable and transporting conventional stool samples to the home country is inconvenient. We evaluated the use of Hemoccult cards for stool sampling combined with a multiplex PCR for the detection of model viral, bacterial, and protozoal TD pathogens. Methods . Following the creation of serial dilutions for each model pathogen, last positive dilution steps (LPDs) and thereof calculated last positive sample concentrations (LPCs) were compared between conventional stool samples and card samples. Furthermore, card samples were tested after a prolonged time interval simulating storage during a travel duration of up to 6 weeks. Results . The LPDs/LPCs were comparable to testing of conventional stool samples. After storage on Hemoccult cards, the recovery rate was 97.6% for C. jejuni , 100% for E . histolytica , 97.6% for norovirus GI, and 100% for GII. Detection of expected pathogens was possible at weekly intervals up to 42 days. Conclusion . Stool samples on Hemoccult cards stored at room temperature can be used in combination with a multiplex PCR as a reliable tool for testing of TD pathogens.

Ladders and Easels and Stools, Oh My!

ERIC Educational Resources Information Center

Greenman, Geri

2002-01-01

Describes an art lesson for high school seniors in an intermediate oil painting class. Explains that the teacher set up a still life with a ladder, easel, and a stool with a white background to capture the shadows. States that the students painted their still life in oil. (CMK)

Stool antigen immunodetection for diagnosis of Giardia duodenalis infection in human subjects with HIV and cancer.

PubMed

Nooshadokht, Maryam; Kalantari-Khandani, Behjat; Sharifi, Iraj; Kamyabi, Hossein; Liyanage, Namal P M; Lagenaur, Laurel A; Kagnoff, Martin F; Singer, Steven M; Babaei, Zahra; Solaymani-Mohammadi, Shahram

2017-10-01

Human infection with the protozoan parasite Giardia duodenalis is one the most common parasitic diseases worldwide. Higher incidence rates of giardiasis have been reported from human subjects with multiple debilitating chronic conditions, including hypogammaglobulinemia and common variable immunodeficiency (CVID). In the current study, stool specimens were collected from 199 individuals diagnosed with HIV or cancer and immunocompetent subjects. The sensitivity of microscopy-based detection on fresh stool preparations, trichrome staining and stool antigen immunodetection for the diagnosis of G. duodenalis were 36%, 45.5% and 100%, respectively when compared with a highly sensitive stool-based PCR method as the gold standard. Further multilocus molecular analyses using glutamate dehydrogenase (gdh) and triose phosphate isomerase (tpi) loci demonstrated that the AI genotype of G. duodenalis was the most prevalent, followed by the AII genotype and mixed (AI+B) infections. We concluded that stool antigen immunodetection-based immunoassays and stool-based PCR amplification had comparable sensitivity and specificity for the diagnosis of G. duodenalis infections in these populations. Stool antigen detection-based diagnostic modalities are rapid and accurate and may offer alternatives to conventional microscopy and PCR-based diagnostic methods for the diagnosis of G. duodenalis in human subjects living with HIV or cancer. Copyright © 2017. Published by Elsevier B.V.

Patterns of detection of Strongyloides stercoralis in stool specimens: implications for diagnosis and clinical trials.

PubMed Central

Dreyer, G; Fernandes-Silva, E; Alves, S; Rocha, A; Albuquerque, R; Addiss, D

1996-01-01

Reported efficacies of drugs used to treat Strongyloides stercoralis infection vary widely. Because diagnostic methods are insensitive, therapeutic trials generally require multiple negative posttreatment stool specimens as evidence of drug efficacy. However, only a single positive stool specimen is usually required for study enrollment. To determine the reproducibility of detection of S. stercoralis larvae in the stool, 108 asymptomatic infected men submitted 25 g of fresh stool once a week for eight consecutive weeks for examination by the Baermann technique. During the 8-week study, 239 (27.7%) of 864 stool specimens were positive for S. stercoralis. Rates of detection of larvae in the stool specimens ranged from eight of eight specimens in 3 (2.8%) men to none of eight specimens in 36 (33.3%) men. Of 43 men for whom S. stercoralis was detected in at least two of the first four stool specimens, only 1 (2.3%) man tested negative on all of the next four specimens. In comparison, of 29 men who had detectable larvae in only one of the first four specimens, 22 (75.9%) tested negative on all of the next four samples. Thus, if these 29 men had been enrolled in a therapeutic trial between the first and second sets of four specimens, the efficacy of a drug with no activity against this parasite would have been estimated to be 76%. These data suggest that patterns of S. stercoralis detection vary widely among infected persons and that intermittent larval shedding can lead to inflated estimates of drug efficacy. Before a patient is entered in a clinical trial of drug efficacy, four consecutive stool specimens should be examined for S. stercoralis; only persons with two or more positive specimens should be enrolled. PMID:8880521

Oral diosmectite reduces stool output and diarrhea duration in children with acute watery diarrhea.

PubMed

Dupont, Christophe; Foo, Jimmy Lee Kok; Garnier, Philippe; Moore, Nicholas; Mathiex-Fortunet, Hèlène; Salazar-Lindo, Eduardo

2009-04-01

Diosmectite is a clay used to treat children with acute watery diarrhea. However, its effects on stool output reduction, the key outcome for pediatric antidiarrheal drugs, have not been shown. Two parallel, double-blind studies of diosmectite efficacy on stool reduction were conducted in children 1 to 36 months old in Peru (n = 300) and Malaysia (n = 302). Inclusion criteria included 3 or more watery stools per day for less than 72 hours and weight/height ratios of 0.8 or greater. Exclusion criteria were the need for intravenous rehydration, gross blood in stools, fever higher than 39 degrees C, or current treatment with antidiarrheal or antibiotic medications. Rotavirus status was determined. Diosmectite dosage was 6 g/day (children 1-12 months old) or 12 g/day (children 13-36 months old), given for at least 3 days, followed by half doses until complete recovery. Patients were assigned randomly to groups given diosmectite or placebo, in addition to oral rehydration solution (World Health Organization). Children in each study had comparable average ages and weights. The frequencies of rotavirus infection were 22% in Peru and 12% in Malaysia. Similar amounts of oral rehydration solution were given to children in the diosmectite and placebo groups. Stool output was decreased significantly by diosmectite in both studies, especially among rotavirus-positive children. In pooled data, children had a mean stool output of 94.5 +/- 74.4 g/kg of body weight in the diosmectite group versus 104.1 +/- 94.2 g/kg in the placebo group (P = .002). Diarrhea duration was reduced by diosmectite, which was well tolerated. These results show that diosmectite significantly decreased stool output in children with acute watery diarrhea, especially those who were rotavirus-positive.

Positive guaiac and bloody stool are poor predictors of intussusception.

PubMed

Kimia, Amir A; Williams, Scotty; Hadar, Peter N; Landschaft, Assaf; Porter, John; Bachur, Richard G

2018-06-01

Currant jelly stool is a late manifestation of intussusception and is rarely seen in clinical practice. Other forms of GI bleeding have not been thoroughly studied and little is known about their respective diagnostic values. To assess the predictive value of GI bleeding (positive guaiac test, bloody stool and rectal bleeding in evaluation of intussusception. We performed a retrospective cross-sectional study cohort of all children, ages 1month-6years of age, who had an abdominal ultrasound obtained evaluating for intussusception over 5year period. We identified intussusception if diagnosed by ultrasound, air-contrast enema or surgery. Univariate and a multivariate logistic regression analysis were performed. During the study period 1258 cases met the study criteria; median age was 1.7years (IQR 0.8, 2.9) and 37% were females. Overall 176 children had intussusception; 153 (87%) were ileo-colic and 23 were ileo-ileal. Univariate risk ratio and adjusted Odds ratio were 1.3 (95% CI, 0.8, 2.0) and 1.3 (0.7, 2.4) for positive guaiac test, 1.1 (0.6, 2.1) and 0.9 (0.3, 3.0) for bloody stool, and 1.7 (1.02, 2.8) and 1.3 (0.5, 3.1) for rectal bleeding . Blood in stool, whether visible or tested by guaiac test has poor diagnostic performance in the evaluation of intussusception and is not independently predictive of intussusception. If the sole purpose of a rectal exam in these patients is for guaiac testing it should be reconsidered. Copyright © 2017 Elsevier Inc. All rights reserved.

An optimised protocol for molecular identification of Eimeria from chickens☆

PubMed Central

Kumar, Saroj; Garg, Rajat; Moftah, Abdalgader; Clark, Emily L.; Macdonald, Sarah E.; Chaudhry, Abdul S.; Sparagano, Olivier; Banerjee, Partha S.; Kundu, Krishnendu; Tomley, Fiona M.; Blake, Damer P.

2014-01-01

Molecular approaches supporting identification of Eimeria parasites infecting chickens have been available for more than 20 years, although they have largely failed to replace traditional measures such as microscopy and pathology. Limitations of microscopy-led diagnostics, including a requirement for specialist parasitological expertise and low sample throughput, are yet to be outweighed by the difficulties associated with accessing genomic DNA from environmental Eimeria samples. A key step towards the use of Eimeria species-specific PCR as a sensitive and reproducible discriminatory tool for use in the field is the production of a standardised protocol that includes sample collection and DNA template preparation, as well as primer selection from the numerous PCR assays now published. Such a protocol will facilitate development of valuable epidemiological datasets which may be easily compared between studies and laboratories. The outcome of an optimisation process undertaken in laboratories in India and the UK is described here, identifying four steps. First, samples were collected into a 2% (w/v) potassium dichromate solution. Second, oocysts were enriched by flotation in saturated saline. Third, genomic DNA was extracted using a QIAamp DNA Stool mini kit protocol including a mechanical homogenisation step. Finally, nested PCR was carried out using previously published primers targeting the internal transcribed spacer region 1 (ITS-1). Alternative methods tested included sample processing in the presence of faecal material, DNA extraction using a traditional phenol/chloroform protocol, the use of SCAR multiplex PCR (one tube and two tube versions) and speciation using the morphometric tool COCCIMORPH for the first time with field samples. PMID:24138724

Analysis of DNA Methylation Status in Bodily Fluids for Early Detection of Cancer

PubMed Central

Yokoi, Keigo; Yamashita, Keishi; Watanabe, Masahiko

2017-01-01

Epigenetic alterations by promoter DNA hypermethylation and gene silencing in cancer have been reported over the past few decades. DNA hypermethylation has great potential to serve as a screening marker, a prognostic marker, and a therapeutic surveillance marker in cancer clinics. Some bodily fluids, such as stool or urine, were obtainable without any invasion to the body. Thus, such bodily fluids were suitable samples for high throughput cancer surveillance. Analyzing the methylation status of bodily fluids around the cancer tissue may, additionally, lead to the early detection of cancer, because several genes in cancer tissues are reported to be cancer-specifically hypermethylated. Recently, several studies that analyzed the methylation status of DNA in bodily fluids were conducted, and some of the results have potential for future development and further clinical use. In fact, a stool DNA test was approved by the U.S. Food and Drug Administration (FDA) for the screening of colorectal cancer. Another promising methylation marker has been identified in various bodily fluids for several cancers. We reviewed studies that analyzed DNA methylation in bodily fluids as a less-invasive cancer screening. PMID:28358330

High Prevalence of Methanobrevibacter smithii and Methanosphaera stadtmanae Detected in the Human Gut Using an Improved DNA Detection Protocol

PubMed Central

Dridi, Bédis; Henry, Mireille; El Khéchine, Amel; Raoult, Didier; Drancourt, Michel

2009-01-01

Background The low and variable prevalence of Methanobrevibacter smithii and Methanosphaera stadtmanae DNA in human stool contrasts with the paramount role of these methanogenic Archaea in digestion processes. We hypothesized that this contrast is a consequence of the inefficiencies of current protocols for archaeon DNA extraction. We developed a new protocol for the extraction and PCR-based detection of M. smithii and M. stadtmanae DNA in human stool. Methodology/Principal Findings Stool specimens collected from 700 individuals were filtered, mechanically lysed twice, and incubated overnight with proteinase K prior to DNA extraction using a commercial DNA extraction kit. Total DNA was used as a template for quantitative real-time PCR targeting M. smithii and M. stadtmanae 16S rRNA and rpoB genes. Amplification of 16S rRNA and rpoB yielded positive detection of M. smithii in 95.7% and M. stadtmanae in 29.4% of specimens. Sequencing of 16S rRNA gene PCR products from 30 randomly selected specimens (15 for M. smithii and 15 for M. stadtmanae) yielded a sequence similarity of 99–100% using the reference M. smithii ATCC 35061 and M. stadtmanae DSM 3091 sequences. Conclusions/Significance In contrast to previous reports, these data indicate a high prevalence of the methanogens M. smithii and M. stadtmanae in the human gut, with the former being an almost ubiquitous inhabitant of the intestinal microbiome. PMID:19759898

Validation of the 3-day rule for stool bacterial tests in Japan.

PubMed

Kobayashi, Masanori; Sako, Akahito; Ogami, Toshiko; Nishimura, So; Asayama, Naoki; Yada, Tomoyuki; Nagata, Naoyoshi; Sakurai, Toshiyuki; Yokoi, Chizu; Kobayakawa, Masao; Yanase, Mikio; Masaki, Naohiko; Takeshita, Nozomi; Uemura, Naomi

2014-01-01

Stool cultures are expensive and time consuming, and the positive rate of enteric pathogens in cases of nosocomial diarrhea is low. The 3-day rule, whereby clinicians order a Clostridium difficile (CD) toxin test rather than a stool culture for inpatients developing diarrhea >3 days after admission, has been well studied in Western countries. The present study sought to validate the 3-day rule in an acute care hospital setting in Japan. Stool bacterial and CD toxin test results for adult patients hospitalized in an acute care hospital in 2008 were retrospectively analyzed. Specimens collected after an initial positive test were excluded. The positive rate and cost-effectiveness of the tests were compared among three patient groups. The adult patients were divided into three groups for comparison: outpatients, patients hospitalized for ≤3 days and patients hospitalized for ≥4 days. Over the 12-month period, 1,597 stool cultures were obtained from 992 patients, and 880 CD toxin tests were performed in 529 patients. In the outpatient, inpatient ≤3 days and inpatient ≥4 days groups, the rate of positive stool cultures was 14.2%, 3.6% and 1.3% and that of positive CD toxin tests was 1.9%, 7.1% and 8.5%, respectively. The medical costs required to obtain one positive result were 9,181, 36,075 and 103,600 JPY and 43,200, 11,333 and 9,410 JPY, respectively. The 3-day rule was validated for the first time in a setting other than a Western country. Our results revealed that the "3-day rule" is also useful and cost-effective in Japan.

Improvement in the detection rate of diarrhoeagenic bacteria in human stool specimens by a rapid real-time PCR assay.

PubMed

Iijima, Yoshio; Asako, Nahoko T; Aihara, Masanori; Hayashi, Kozaburo

2004-07-01

A rapid laboratory system has been developed and evaluated that can simultaneously identify major diarrhoeagenic bacteria, including Salmonella enterica, Vibrio parahaemolyticus, Campylobacter jejuni and Shiga toxin-producing Escherichia coli, in stool specimens by real-time PCR. Specific identification was achieved by using selective TaqMan probes, detecting two targets in each pathogen. A positive result was scored only when both targets of a pathogen were amplified and the difference between threshold cycles for detection was less than five. Diagnosis of enteric bacterial infections using this highly sensitive method, including DNA extraction and real-time PCR, requires only 3 h. Forty stool specimens related to suspected food poisoning outbreaks were analysed: 16 (40%) of these samples were found to be positive for diarrhoeagenic bacteria using a conventional culture method; 28 (70%) were positive using the real-time PCR assay. Of the 12 PCR-positive but culture-negative cases, 11 patients had consumed pathogen-contaminated or high-risk food. Analysis of faecal samples from 105 outpatients who complained of diarrhoea and/or abdominal pain identified 19 (18%) patients as being positive for diarrhoeagenic bacteria using the culture method. An additional six (6%) patients were found to be positive by PCR analysis.

Preanalytical blood sample workup for cell-free DNA analysis using Droplet Digital PCR for future molecular cancer diagnostics.

PubMed

van Ginkel, Joost H; van den Broek, Daan A; van Kuik, Joyce; Linders, Dorothé; de Weger, Roel; Willems, Stefan M; Huibers, Manon M H

2017-10-01

In current molecular cancer diagnostics, using blood samples of cancer patients for the detection of genetic alterations in plasma (cell-free) circulating tumor DNA (ctDNA) is an emerging practice. Since ctDNA levels in blood are low, highly sensitive Droplet Digital PCR (ddPCR) can be used for detecting rare mutational targets. In order to perform ddPCR on blood samples, a standardized procedure for processing and analyzing blood samples is necessary to facilitate implementation into clinical practice. Therefore, we assessed the technical sample workup procedure for ddPCR on blood plasma samples. Blood samples from healthy individuals, as well as lung cancer patients were analyzed. We compared different methods and protocols for sample collection, storage, centrifugation, isolation, and quantification. Cell-free DNA (cfDNA) concentrations of several wild-type targets and BRAF and EGFR-mutant ctDNA concentrations quantified by ddPCR were primary outcome measurements. Highest cfDNA concentrations were measured in blood collected in serum tubes. No significant differences in cfDNA concentrations were detected between various time points of up to 24 h until centrifugation. Highest cfDNA concentrations were detected after DNA isolation with the Quick cfDNA Serum & Plasma Kit, while plasma isolation using the QIAamp Circulating Nucleic Acid Kit yielded the most consistent results. DdPCR results on cfDNA are highly dependent on multiple factors during preanalytical sample workup, which need to be addressed during the development of this diagnostic tool for cancer diagnostics in the future. © 2017 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Genomic Analysis of Vaccine-Derived Poliovirus Strains in Stool Specimens by Combination of Full-Length PCR and Oligonucleotide Microarray Hybridization

PubMed Central

Laassri, Majid; Dragunsky, Eugenia; Enterline, Joan; Eremeeva, Tatiana; Ivanova, Olga; Lottenbach, Kathleen; Belshe, Robert; Chumakov, Konstantin

2005-01-01

Sabin strains of poliovirus used in the manufacture of oral poliovirus vaccine (OPV) are prone to genetic variations that occur during growth in cell cultures and the organisms of vaccine recipients. Such derivative viruses often have increased neurovirulence and transmissibility, and in some cases they can reestablish chains of transmission in human populations. Monitoring for vaccine-derived polioviruses is an important part of the worldwide campaign to eradicate poliomyelitis. Analysis of vaccine-derived polioviruses requires, as a first step, their isolation in cell cultures, which takes significant time and may yield viral stocks that are not fully representative of the strains present in the original sample. Here we demonstrate that full-length viral cDNA can be PCR amplified directly from stool samples and immediately subjected to genomic analysis by oligonucleotide microarray hybridization and nucleotide sequencing. Most fecal samples from healthy children who received OPV were found to contain variants of Sabin vaccine viruses. Sequence changes in the 5′ untranslated region were common, as were changes in the VP1-coding region, including changes in a major antigenic site. Analysis of stool samples taken from cases of acute flaccid paralysis revealed the presence of mixtures of recombinant polioviruses, in addition to the emergence of new sequence variants. Avoiding the need for cell culture isolation dramatically shortened the time needed for identification and analysis of vaccine-derived polioviruses and could be useful for preliminary screening of clinical samples. The amplified full-length viral cDNA can be archived and used to recover live virus for further virological studies. PMID:15956413

Bacterial community in ancient permafrost alluvium at the Mammoth Mountain (Eastern Siberia).

PubMed

Brouchkov, Anatoli; Kabilov, Marsel; Filippova, Svetlana; Baturina, Olga; Rogov, Victor; Galchenko, Valery; Mulyukin, Andrey; Fursova, Oksana; Pogorelko, Gennady

2017-12-15

Permanently frozen (approx. 3.5Ma) alluvial Neogene sediments exposed in the Aldan river valley at the Mammoth Mountain (Eastern Siberia) are unique, ancient, and poorly studied permafrost environments. So far, the structure of the indigenous bacterial community has remained unknown. Use of 16S metagenomic analysis with total DNA isolation using DNA Spin Kit for Soil (MO-Bio) and QIAamp DNA Stool Mini Kit (Qiagen) has revealed the major and minor bacterial lineages in the permafrost alluvium sediments. In sum, 61 Operational Taxonomic Units (OTUs) with 31,239 reads (Qiagen kit) and 15,404 reads (Mo-Bio kit) could be assigned to the known taxa. Only three phyla, Bacteroidetes, Proteobacteria and Firmicutes, comprised >5% of the OTUs abundance and accounted for 99% of the total reads. OTUs pertaining to the top families (Chitinophagaceae, Caulobacteraceae, Sphingomonadaceae, Bradyrhizobiaceae, Halomonadaceae) held >90% of reads. The abundance of Actinobacteria was less (0.7%), whereas members of other phyla (Deinococcus-Thermus, Cyanobacteria/Chloroplast, Fusobacteria, and Acidobacteria) constituted a minor fraction of reads. The bacterial community in the studied ancient alluvium differs from other permafrost sediments, mainly by predominance of Bacteroidetes (>52%). The diversity of this preserved bacterial community has the potential to cause effects unknown if prompted to thaw and spread with changing climate. Therefore, this study elicits further reason to study how reintroduction of these ancient bacteria could affect the surrounding ecosystem, including current bacterial species. Copyright © 2017 Elsevier B.V. All rights reserved.

Extracting DNA from FFPE Tissue Biospecimens Using User-Friendly Automated Technology: Is There an Impact on Yield or Quality?

PubMed

Mathieson, William; Guljar, Nafia; Sanchez, Ignacio; Sroya, Manveer; Thomas, Gerry A

2018-05-03

DNA extracted from formalin-fixed, paraffin-embedded (FFPE) tissue blocks is amenable to analytical techniques, including sequencing. DNA extraction protocols are typically long and complex, often involving an overnight proteinase K digest. Automated platforms that shorten and simplify the process are therefore an attractive proposition for users wanting a faster turn-around or to process large numbers of biospecimens. It is, however, unclear whether automated extraction systems return poorer DNA yields or quality than manual extractions performed by experienced technicians. We extracted DNA from 42 FFPE clinical tissue biospecimens using the QiaCube (Qiagen) and ExScale (ExScale Biospecimen Solutions) automated platforms, comparing DNA yields and integrities with those from manual extractions. The QIAamp DNA FFPE Spin Column Kit was used for manual and QiaCube DNA extractions and the ExScale extractions were performed using two of the manufacturer's magnetic bead kits: one extracting DNA only and the other simultaneously extracting DNA and RNA. In all automated extraction methods, DNA yields and integrities (assayed using DNA Integrity Numbers from a 4200 TapeStation and the qPCR-based Illumina FFPE QC Assay) were poorer than in the manual method, with the QiaCube system performing better than the ExScale system. However, ExScale was fastest, offered the highest reproducibility when extracting DNA only, and required the least intervention or technician experience. Thus, the extraction methods have different strengths and weaknesses, would appeal to different users with different requirements, and therefore, we cannot recommend one method over another.

Picky eating in preschool children: Associations with dietary fibre intakes and stool hardness

PubMed Central

Taylor, Caroline M.; Northstone, Kate; Wernimont, Susan M.; Emmett, Pauline M.

2018-01-01

It has been suggested that constipation may be associated with picky eating. Constipation is a common condition in childhood and a low intake of dietary fibre may be a risk factor. Differences in fibre intake between picky and non-picky children and its relation to stool consistency is currently not well-understood. Children enrolled in the Avon Longitudinal Study of Parents and Children identified as picky eaters (PE) were compared with non-picky eaters (NPE): (1) to determine dietary fibre intake at 38 months; (2) to investigate whether any difference in dietary fibre intake was predictive of usual stool hardness at 42 months. PE was identified from questionnaires at 24 and 38 months. Usual stool hardness was identified from a questionnaire at 42 months. Dietary intake was assessed at 38 months with a food frequency questionnaire. Dietary fibre intake was lower in PE than NPE (mean difference −1.4 (95% CI −1.6, −1.2) g/day, p < 0.001). PE was strongly associated with dietary fibre intake (adjusted regression model; unstandardised B −1.44 (95% CI −1.62, −1.24) g/day, p < 0.001). PE had a lower percentage of fibre from vegetables compared with NPE (8.9% vs 15.7%, respectively, p < 0.001). There was an association between PE and usually having hard stools (adjusted multinomial model; OR 1.31, 95% CI 1.07, 1.61; p = 0.010). This was attenuated when dietary fibre was included in the model, suggesting that fibre intake mediated the association (OR 1.16, 95% CI 0.94, 1.43, p = 0.180). Picky eating in 3-year-old children was associated with an increased prevalence of usually having hard stools. This association was mediated by low dietary fibre intake, particularly from vegetables, in PE. For children with PE, dietary advice aimed at increasing fibre intake may help avoid hard stools. PMID:26879221

Picky eating in preschool children: Associations with dietary fibre intakes and stool hardness.

PubMed

Taylor, Caroline M; Northstone, Kate; Wernimont, Susan M; Emmett, Pauline M

2016-05-01

It has been suggested that constipation may be associated with picky eating. Constipation is a common condition in childhood and a low intake of dietary fibre may be a risk factor. Differences in fibre intake between picky and non-picky children and its relation to stool consistency is currently not well-understood. Children enrolled in the Avon Longitudinal Study of Parents and Children identified as picky eaters (PE) were compared with non-picky eaters (NPE): (1) to determine dietary fibre intake at 38 months; (2) to investigate whether any difference in dietary fibre intake was predictive of usual stool hardness at 42 months. PE was identified from questionnaires at 24 and 38 months. Usual stool hardness was identified from a questionnaire at 42 months. Dietary intake was assessed at 38 months with a food frequency questionnaire. Dietary fibre intake was lower in PE than NPE (mean difference -1.4 (95% CI -1.6, -1.2) g/day, p < 0.001). PE was strongly associated with dietary fibre intake (adjusted regression model; unstandardised B -1.44 (95% CI -1.62, -1.24) g/day, p < 0.001). PE had a lower percentage of fibre from vegetables compared with NPE (8.9% vs 15.7%, respectively, p < 0.001). There was an association between PE and usually having hard stools (adjusted multinomial model; OR 1.31, 95% CI 1.07, 1.61; p = 0.010). This was attenuated when dietary fibre was included in the model, suggesting that fibre intake mediated the association (OR 1.16, 95% CI 0.94, 1.43, p = 0.180). Picky eating in 3-year-old children was associated with an increased prevalence of usually having hard stools. This association was mediated by low dietary fibre intake, particularly from vegetables, in PE. For children with PE, dietary advice aimed at increasing fibre intake may help avoid hard stools. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Blastocystis sp. in Irritable Bowel Syndrome (IBS)--Detection in Stool Aspirates during Colonoscopy.

PubMed

Ragavan, Nanthiney Devi; Kumar, Suresh; Chye, Tan Tian; Mahadeva, Sanjiv; Shiaw-Hooi, Ho

2015-01-01

Blastocystis is one of the most common gut parasites found in the intestinal tract of humans and animals. Its' association with IBS is controversial, possibly as a result of irregular shedding of parasites in stool and variation in stool detection. We aimed to screen for Blastocystis in colonic stool aspirate samples in adult patients with and without IBS undergoing colonoscopy for various indications and measure the interleukin levels (IL-8, IL-3 and IL-5). In addition to standard stool culture techniques, polymerase chain reaction (PCR) techniques were employed to detect and subtype Blastocystis. All the serum samples collected were subjected for ELISA studies to measure the interleukin levels (IL-8, IL-3 and IL-5). Among 109 (IBS n = 35 and non-IBS n = 74) adults, direct stool examination and culture of colonic aspirates were initially negative for Blastocystis. However, PCR analysis detected Blastocystis in 6 (17%) IBS and 4 (5.5%) non-IBS patients. In the six positive IBS patients by PCR method, subtype 3 was shown to be the most predominant (3/6: 50%) followed by subtype 4 (2/6; 33.3%) and subtype 5 (1/6; 16.6%). IL-8 levels were significantly elevated in the IBS Blasto group and IBS group (p<0.05) compared to non-IBS and non-IBS Blasto group. The level of IL-3 in were seen to be significantly higher in than IBS Blasto group and IBS group (p<0.05) compared to non-IBS. Meanwhile, the IL-5 levels were significantly higher in IBS Blasto group (p<0.05) compared to non-IBS and non-IBS Blasto group. This study implicates that detecting Blastosystis by PCR method using colonic aspirate samples during colonoscopy, suggests that this may be a better method for sample collection due to the parasite's irregular shedding in Blastocystis-infected stools. Patients with IBS infected with parasite showed an increase in the interleukin levels demonstrate that Blastocystis does have an effect in the immune system.

Impact of palm olein in infant formulas on stool consistency and frequency: a meta-analysis of randomized clinical trials

PubMed Central

Lasekan, John B.; Hustead, Deborah S.; Masor, Marc; Murray, Robert

2017-01-01

ABSTRACT Background: Meta-analysis studies have documented that palm olein (PALM) predominant formulas reduce calcium and fat absorption, and bone mineralization in infants, but none have been documented for stool consistency and frequency. Objective: The study objective was to conduct a meta-analysis of published randomized clinical trials (RCTs) on the effect of PALM-based formulas on stool consistency and frequency in infants. Design: A literature search was conducted in BIOSIS Previews®, Embase®, Embase® Alert, MEDLINE® and Cochrane databases. PALM-based RCTs with available stool outcomes were selected and meta-analyzed. Mean rank stool consistency (MRSC, primary outcome) and stool frequency (secondary outcome) were compared between infants fed PALM-based and PALM-free formulas (NoPALM), using random effects model. Results: Nine out of identified16 studies were meta-analyzed. The mean MRSC (scale of 1 = watery to 5 = hard) in the NoPALM-fed infants was lower (softer stools) compared to the PALM-fed infants (mean difference ‒0.355, 95% Confidence Interval [CI] of ‒0.472 to ‒0.239, p < 0.001). Difference for stool frequency was not significant (p = 0.613). Conclusion: Meta-analysis of RCTs indicated that NoPALM-fed infants have significantly softer stools but similar stool frequencies versus PALM-fed infants, despite differences in study types and design. Future meta-analysis could benefit from including comparison with human milk-fed infants. PMID:28659741

Aeromonas isolates from human diarrheic stool and groundwater compared by pulsed-field gel electrophoresis.

PubMed

Borchardt, Mark A; Stemper, Mary E; Standridge, Jon H

2003-02-01

Gastrointestinal infections of Aeromonas species are generally considered waterborne; for this reason, Aeromonas hydrophila has been placed on the United States Environmental Protection Agency Contaminant Candidate List of emerging pathogens in drinking water. In this study, we compared pulsed-field gel electrophoresis patterns of Aeromonas isolates from stool specimens of patients with diarrhea with Aeromonas isolates from patients' drinking water. Among 2,565 diarrheic stool specimens submitted to a Wisconsin clinical reference laboratory, 17 (0.66%) tested positive for Aeromonas. Groundwater isolates of Aeromonas were obtained from private wells throughout Wisconsin and the drinking water of Aeromonas-positive patients. The analysis showed that the stool and drinking water isolates were genetically unrelated, suggesting that in this population Aeromonas gastrointestinal infections were not linked with groundwater exposures.

Isolation and characterization of Yersinia-specific bacteriophages from pig stools in Finland.

PubMed

Salem, M; Virtanen, S; Korkeala, H; Skurnik, M

2015-03-01

Bacteriophages infect bacteria, and they are present everywhere in the world including the intestinal tracts of animals. Yersiniosis is a common foodborne infection caused by Yersinia enterocolitica and Yersinia pseudotuberculosis. As these bacteria are frequently isolated from pigs, we wanted to know whether Yersinia-specific bacteriophages are also present in the pig stools and, if so, whether there is a positive or negative association between the prevalence of the Yersinia phages and the pathogenic Yersinia in the stool samples. Altogether 793 pig stool samples collected between November 2010 and March 2012 from 14 Finnish pig farms were screened for the presence of bacteriophages able to infect Y. enterocolitica serotype O:3, O:5,27 or O:9 strains, or Y. pseudotuberculosis serotype O:1a, O:1b or O:3 strains. Yersinia phages were isolated from 90 samples from eight farms. Yersinia enterocolitica O:3 was infected by 59 phages, 28 phages infected serotypes O:3 and O:5,27, and eight phages infected serotypes O:3, O:5,27 and O:9, and Y. pseudotuberculosis O:1a by eight phages. Many phages originating from pigs in the same farm were identical based on their restriction enzyme digestion patterns; 20 clearly different phages were selected for further characterization. Host ranges of these phages were tested with 94 Yersinia strains. Six of the phages infected eight strains, 13 phages infected three strains, and one phage infected only one strain, indicating that the phages had a relatively narrow host range. There was a clear association between the presence of the host bacteria and specific phages in the stools. The isolated bacteriophages may have potential as biocontrol agents for yersiniosis in both humans and pigs in future, and as alternatives or in addition to antibiotics. To our knowledge, this is the first reported isolation of Yersinia-specific phages from pig stool samples. © 2014 The Society for Applied Microbiology.

Development of a PCR Assay for Diagnosing Trematode (Opisthorchis and Haplorchis) Infections in Human Stools

PubMed Central

Kanda, Seiji; Laimanivong, Sakhone; Shimono, Takaki; Darcy, Andrew Waleluma; Phyaluanglath, Amphay; Mishima, Nobuyuki; Nishiyama, Toshimasa

2017-01-01

We developed a combined conventional polymerase chain reaction (PCR) and real-time PCR (qPCR)-based assay for detecting and discriminating between Opisthorchis viverrini and Haplorchis taichui parasite infections. The first PCR amplifies the mitochondrial cytochrome c oxidase subunit I (COI) genes of parasites, and differential diagnosis is achieved by performing qPCR with specific primers and SYBR Green I. The detection limit of the assay was found to be 2.0 × 102 plasmid copies in a test in which a stool sample was spiked with a single egg, which is equivalent to 5 eggs per gram (EPG). The testing of 34 clinical stool samples that had been demonstrated to contain “Opisthorchis-like” eggs by microscopy showed that the novel assay exhibited a sensitivity of 100% for “Opisthorchis-like” parasitic infections, and 71% and 91% of these samples were found to be infected with O. viverrini and H. taichui, respectively. A further four parasitic infections were diagnosed in the 16 negative samples, and the microscopic findings of these samples were confirmed to be false negatives by sequencing analysis. The assay also displayed high specificity during the testing of 10 samples containing other common parasites. The fact that our qPCR SYBR Green I–based assay detected submicroscopic traces of parasitic DNA and was able to differentiate between parasites that produce eggs with similar morphologies indicates that it has a good potential for development of diagnostic application to use in areas where multiple parasites coexist. PMID:27821695

An optimised protocol for molecular identification of Eimeria from chickens.

PubMed

Kumar, Saroj; Garg, Rajat; Moftah, Abdalgader; Clark, Emily L; Macdonald, Sarah E; Chaudhry, Abdul S; Sparagano, Olivier; Banerjee, Partha S; Kundu, Krishnendu; Tomley, Fiona M; Blake, Damer P

2014-01-17

Molecular approaches supporting identification of Eimeria parasites infecting chickens have been available for more than 20 years, although they have largely failed to replace traditional measures such as microscopy and pathology. Limitations of microscopy-led diagnostics, including a requirement for specialist parasitological expertise and low sample throughput, are yet to be outweighed by the difficulties associated with accessing genomic DNA from environmental Eimeria samples. A key step towards the use of Eimeria species-specific PCR as a sensitive and reproducible discriminatory tool for use in the field is the production of a standardised protocol that includes sample collection and DNA template preparation, as well as primer selection from the numerous PCR assays now published. Such a protocol will facilitate development of valuable epidemiological datasets which may be easily compared between studies and laboratories. The outcome of an optimisation process undertaken in laboratories in India and the UK is described here, identifying four steps. First, samples were collected into a 2% (w/v) potassium dichromate solution. Second, oocysts were enriched by flotation in saturated saline. Third, genomic DNA was extracted using a QIAamp DNA Stool mini kit protocol including a mechanical homogenisation step. Finally, nested PCR was carried out using previously published primers targeting the internal transcribed spacer region 1 (ITS-1). Alternative methods tested included sample processing in the presence of faecal material, DNA extraction using a traditional phenol/chloroform protocol, the use of SCAR multiplex PCR (one tube and two tube versions) and speciation using the morphometric tool COCCIMORPH for the first time with field samples. Copyright © 2013 Dirk Vulpius The Authors. Published by Elsevier B.V. All rights reserved.

High-quality and -quantity DNA extraction from frozen archival blood clots for genotyping of single-nucleotide polymorphisms.

PubMed

Bank, Steffen; Nexø, Bjørn Andersen; Andersen, Vibeke; Vogel, Ulla; Andersen, Paal Skytt

2013-06-01

The recovery of biological samples for genetic epidemiological studies can be cumbersome. Blood clots are routinely collected for serological examinations. However, the extraction of DNA from blood clots can be difficult and often results in low yields. The aim was to compare the efficiency of commercial purification kits for extracting DNA from long-term frozen clotted blood. Serum tubes with clotted blood were stored at -20°C for 1 to 2.5 years before DNA extraction. DNA was extracted from 10 blood clot samples using PureGene (Qiagen) with and without glycogen, the QIAamp DNA Micro kit (Qiagen), and the Nucleospin 96 Blood kit (Macherey-Nagel). Furthermore, blood clots from 1055 inflammatory bowel disease patients were purified using the Maxwell 16 Blood purification kit (Promega). The DNA was extracted according to the manufacturers` instructions and real-time PCR and the A(260)/A(280) ratio were used to evaluate the quality of the extracted DNA. The highest DNA yield was obtained by the Maxwell 16 Blood purification kit (Promega) with a median of 4.90 μg (range 0.8-25 μg) pr 300 μL total blood. PureGene with glycogen (Qiagen) had the second highest yield with a median of 0.65 μg (range 0.5-2.6 μg) pr 300 μL total blood. The yield obtained by the different commercial kits varied considerably. Our work demonstrates that high-quality and -quantity DNA can be extracted with the Maxwell 16 Blood purification kit (Promega) from cryopreserved blood clots, even after prolonged storage. The recovered DNA served as a reliable PCR template for single-nucleotide polymorphism assays.

Accuracy of early detection of colorectal tumours by stool methylation markers: A meta-analysis

PubMed Central

Zhang, Hu; Qi, Jian; Wu, Ya-Qiong; Zhang, Ping; Jiang, Jun; Wang, Qi-Xian; Zhu, You-Qing

2014-01-01

AIM: To evaluate the accuracy of methylation of genes in stool samples for diagnosing colorectal tumours. METHODS: Electronic databases including PubMed, Web of Science, Chinese Journals Full-Text Database and Wanfang Journals Full-Text Database were searched to find relevant original articles about methylated genes to be used in diagnosing colorectal tumours. A quality assessment of diagnostic accuracy studies tool (QADAS) was used to evaluate the quality of the included articles, and the Meta-disc 1.4 and SPSS 13.0 software programs were used for data analysis. RESULTS: Thirty-seven articles met the inclusion criteria, and 4484 patients were included. The sensitivity and specificity for the detection of colorectal cancer (CRC) were 73% (95%CI: 71%-75%) and 92% (95%CI: 90%-93%), respectively. For adenoma, the sensitivity and specificity were 51% (95%CI: 47%-54%) and 92% (95%CI: 90%-93%), respectively. Pooled diagnostic performance of SFRP2 methylation for CRC provided the following results: the sensitivity was 79% (95%CI: 75%-82%), the specificity was 93% (95%CI: 90%-96%), the diagnostic OR was 47.57 (95%CI: 20.08-112.72), the area under the curve was 0.9565. Additionally, the results of accuracy of SFRP2 methylation for detecting colorectal adenomas were as follows: sensitivity was 43% (95%CI: 38%-49%), specificity was 94% (95%CI: 91%-97%), the diagnostic OR was 11.06 (95%CI: 5.77-21.18), and the area under the curve was 0.9563. CONCLUSION: Stool-based DNA testing may be useful for noninvasively diagnosing colorectal tumours and SFRP2 methylation is a promising marker that has great potential in early CRC diagnosis. PMID:25320544

Accuracy of early detection of colorectal tumours by stool methylation markers: a meta-analysis.

PubMed

Zhang, Hu; Qi, Jian; Wu, Ya-Qiong; Zhang, Ping; Jiang, Jun; Wang, Qi-Xian; Zhu, You-Qing

2014-10-14

To evaluate the accuracy of methylation of genes in stool samples for diagnosing colorectal tumours. Electronic databases including PubMed, Web of Science, Chinese Journals Full-Text Database and Wanfang Journals Full-Text Database were searched to find relevant original articles about methylated genes to be used in diagnosing colorectal tumours. A quality assessment of diagnostic accuracy studies tool (QADAS) was used to evaluate the quality of the included articles, and the Meta-disc 1.4 and SPSS 13.0 software programs were used for data analysis. Thirty-seven articles met the inclusion criteria, and 4484 patients were included. The sensitivity and specificity for the detection of colorectal cancer (CRC) were 73% (95%CI: 71%-75%) and 92% (95%CI: 90%-93%), respectively. For adenoma, the sensitivity and specificity were 51% (95%CI: 47%-54%) and 92% (95%CI: 90%-93%), respectively. Pooled diagnostic performance of SFRP2 methylation for CRC provided the following results: the sensitivity was 79% (95%CI: 75%-82%), the specificity was 93% (95%CI: 90%-96%), the diagnostic OR was 47.57 (95%CI: 20.08-112.72), the area under the curve was 0.9565. Additionally, the results of accuracy of SFRP2 methylation for detecting colorectal adenomas were as follows: sensitivity was 43% (95%CI: 38%-49%), specificity was 94% (95%CI: 91%-97%), the diagnostic OR was 11.06 (95%CI: 5.77-21.18), and the area under the curve was 0.9563. Stool-based DNA testing may be useful for noninvasively diagnosing colorectal tumours and SFRP2 methylation is a promising marker that has great potential in early CRC diagnosis.

Aeromonas Isolates from Human Diarrheic Stool and Groundwater Compared by Pulsed-Field Gel Electrophoresis

PubMed Central

Stemper, Mary E.; Standridge, Jon H.

2003-01-01

Gastrointestinal infections of Aeromonas species are generally considered waterborne; for this reason, Aeromonas hydrophila has been placed on the United States Environmental Protection Agency Contaminant Candidate List of emerging pathogens in drinking water. In this study, we compared pulsed-field gel electrophoresis patterns of Aeromonas isolates from stool specimens of patients with diarrhea with Aeromonas isolates from patients’ drinking water. Among 2,565 diarrheic stool specimens submitted to a Wisconsin clinical reference laboratory, 17 (0.66%) tested positive for Aeromonas. Groundwater isolates of Aeromonas were obtained from private wells throughout Wisconsin and the drinking water of Aeromonas-positive patients. The analysis showed that the stool and drinking water isolates were genetically unrelated, suggesting that in this population Aeromonas gastrointestinal infections were not linked with groundwater exposures. PMID:12603994

Rice solution and World Health Organization solution by gastric infusion for high stool output diarrhea.

PubMed

Mota-Hernández, F; Bross-Soriano, D; Pérez-Ricardez, M L; Velásquez-Jones, L

1991-08-01

We sought to determine the efficacy of three different types of treatment in children with acute diarrhea who, during the oral rehydration period, had high stool output (greater than 10 mL/kg per hour). Sixty-six children, aged 1 to 18 months, with an average stool output of 22.6 mL/kg per hour were randomly distributed into three groups: group 1 received a rice flour solution, group 2 received the World Health Organization rehydration solution by gastric infusion, and group 3 continued to receive this solution orally. In all three groups, a decrease in stool output was observed, with the higher decrease observed in group 1 patients. Such a decrease facilitated rehydration of all 22 patients in group 1 (100%) in 3.3 +/- 1.5 hours, 16 (73%) in group 2 in 4.3 +/- 2.1 hours, and 15 (69%) in group 3 in 4.9 +/- 2.0 hours. No complications were observed. These data indicate that the rice flour solution is effective in children with high stool output diarrhea.

Ultrasensitive Detection of Shigella Species in Blood and Stool.

PubMed

Luo, Jieling; Wang, Jiapeng; Mathew, Anup S; Yau, Siu-Tung

2016-02-16

A modified immunosensing system with voltage-controlled signal amplification was used to detect Shigella in stool and blood matrixes at the single-digit CFU level. Inactivated Shigella was spiked in these matrixes and detected directly. The detection was completed in 78 min. Detection limits of 21 CFU/mL and 18 CFU/mL were achieved in stool and blood, respectively, corresponding to 2-7 CFUs immobilized on the detecting electrode. The outcome of the detection of extremely low bacterium concentration, i.e., below 100 CFU/mL, blood samples show a random nature. An analysis of the detection probabilities indicates the correlation between the sample volume and the success of detection and suggests that sample volume is critical for ultrasensitive detection of bacteria. The calculated detection limit is qualitatively in agreement with the empirically determined detection limit. The demonstrated ultrasensitive detection of Shigella on the single-digit CFU level suggests the feasibility of the direct detection of the bacterium in the samples without performing a culture.

Ancient DNA analyses of museum specimens from selected Presbytis (primate: Colobinae) based on partial Cyt b sequences

NASA Astrophysics Data System (ADS)

Aifat, N. R.; Yaakop, S.; Md-Zain, B. M.

2016-11-01

The IUCN Red List of Threatened Species has categorized Malaysian primates from being data deficient to critically endanger. Thus, ancient DNA analyses hold great potential to understand phylogeny, phylogeography and population history of extinct and extant species. Museum samples are one of the alternatives to provide important sources of biological materials for a large proportion of ancient DNA studies. In this study, a total of six museum skin samples from species Presbytis hosei (4 samples) and Presbytis frontata (2 samples), aged between 43 and 124 years old were extracted to obtain the DNA. Extraction was done by using QIAGEN QIAamp DNA Investigator Kit and the ability of this kit to extract museum skin samples was tested by amplification of partial Cyt b sequence using species-specific designed primer. Two primer pairs were designed specifically for P. hosei and P. frontata, respectively. These primer pairs proved to be efficient in amplifying 200bp of the targeted species in the optimized PCR conditions. The performance of the sequences were tested to determine genetic distance of genus Presbytis in Malaysia. From the analyses, P. hosei is closely related to P. chrysomelas and P. frontata with the value of 0.095 and 0.106, respectively. Cyt b gave a clear data in determining relationships among Bornean species. Thus, with the optimized condition, museum specimens can be used for molecular systematic studies of the Malaysian primates.

[Rice water with and without electrolytes in diarrhea with a high stool output].

PubMed

Mota-Hernández, F; Posadas-Tello, N M; Rodríguez-Leyva, G

1993-12-01

The objective of the study was to determine the efficacy and safety of two rice-based oral rehydration solutions, with and without added electrolyte in children presenting acute diarrheal dehydration with high stool output (> 10 mL/kg/h) during a two-hour rehydration period. Twenty-two patients of one to 18 months old were recruited and randomly distributed into two groups: group A received the rice-based solution without electrolytes, and group B received the rice-based solution with electrolytes. A stool output diminishing was observed in both groups and rehydration was achieved in 4.0 +/- 0.9 hours in 21 patients from group A and in 4.6 +/- 0.9 hours in 13 patients group group B. There was not a statistically significant difference between the groups regarding the laboratory results. The rice-based oral rehydration solution without added electrolytes was useful for rehydration of children presenting high stool output, after administering the WHO/ORS recommended formula during a two-hour period.

New ultrasonographic evaluation of stool and/or gas distribution for treatment of chronic constipation.

PubMed

Manabe, Noriaki; Kamada, Tomoari; Hata, Jiro; Haruma, Ken

2018-03-01

The first aim of this study was to develop a new ultrasonographic method (US) to evaluate stool and/or gas distribution. The second aim was to apply this method to compare stool and/or gas distribution between healthy subjects and patients with chronic constipation and evaluate whether US parameters could be an alternative to the colonic transit time (CTT). We enrolled seven healthy volunteers (four men, three women; mean age 29.3 ± 5.2 years) who underwent US and computed tomography (CT) on the same day to evaluate the reproducibility of US results. We then enrolled 268 patients with chronic constipation (94 men, 174 women; mean age 63.3 ± 4.2 years) and 66 age- and sex-matched healthy subjects (controls). The transverse diameters of four segments of the colon [ascending (AC), transverse (TC), descending (DC), and sigmoid (SC)] and the rectum (R) were measured, and their stool and/or gas distribution was evaluated using the constipation index (CI) [AC + TC + DC + SC + R/5] and left/right (L/R) distribution [(DC + SC)/(AC + TC)]. The CTT was assessed using radiopaque markers. All healthy subjects underwent US and CT successfully, with a sufficiently high reproducibility coefficient for this method and significant correlation between the US and CT parameters. The stool and/or gas distribution evaluated by US showed a significant difference in one of the US parameters between healthy subjects and patients, and the CI was an indirect indicator for the CTT. These findings may assist physicians evaluate stool and/or gas distribution of patients with chronic constipation, which is an indirect indicator for CTT.

Improved method for extraction and detection of Helicobacter pylori DNA in formalin-fixed paraffin embedded gastric biopsies using laser micro-dissection.

PubMed

Loayza, María Fernanda; Villavicencio, Fernando Xavier; Santander, Stephanie Carolina; Baldeón, Manuel; Ponce, Lourdes Karina; Salvador, Iván; Vivar Díaz, Nicolás

2015-01-01

To assess the molecular events exerted by Helicobacter pylori interacting directly with gastric epithelial cells, an improved procedure for microbial DNA isolation from stained hematoxilin-eosin gastric biopsies was developed based on laser micro-dissection (LM) [1]. Few articles have described the use of LM to select and detect H. pylori genome from formalin-fixed paraffin embedded gastric tissue [2]. To improve the yield and quality of DNA isolated from H. pylori contacting intestinal epithelial cells, the following conditions were established after modification of the QIAamp DNA Micro kit. •Use of at least 25 cut sections of 10-20 μm of diameter and 3 μm thick with more than 10 bacteria in each cut.•Lysis with 30 μL of tissue lysis buffer and 20 μL of proteinase K (PK) with the tube in an upside-down position.•The use of thin purification columns with 35 μL of elution buffer. The mean of DNA concentration obtained from 25 LM cut sections was 1.94± 0 .16 ng/μL, and it was efficiently amplified with qPCR in a Bio Rad iCycler instrument. The LM can improve the sample selection and DNA extraction for molecular analysis of H. pylori associated with human gastric epithelium.

The effect of step stool use and provider height on CPR quality during pediatric cardiac arrest: A simulation-based multicentre study.

PubMed

Cheng, Adam; Lin, Yiqun; Nadkarni, Vinay; Wan, Brandi; Duff, Jonathan; Brown, Linda; Bhanji, Farhan; Kessler, David; Tofil, Nancy; Hecker, Kent; Hunt, Elizabeth A

2018-01-01

We aimed to explore whether a) step stool use is associated with improved cardiopulmonary resuscitation (CPR) quality; b) provider adjusted height is associated with improved CPR quality; and if associations exist, c) determine whether just-in-time (JIT) CPR training and/or CPR visual feedback attenuates the effect of height and/or step stool use on CPR quality. We analysed data from a trial of simulated cardiac arrests with three study arms: No intervention; CPR visual feedback; and JIT CPR training. Step stool use was voluntary. We explored the association between 1) step stool use and CPR quality, and 2) provider adjusted height and CPR quality. Adjusted height was defined as provider height + 23 cm (if step stool was used). Below-average height participants were ≤ gender-specific average height; the remainder were above average height. We assessed for interaction between study arm and both adjusted height and step stool use. One hundred twenty-four subjects participated; 1,230 30-second epochs of CPR were analysed. Step stool use was associated with improved compression depth in below-average (female, p=0.007; male, p<0.001) and above-average (female, p=0.001; male, p<0.001) height providers. There is an association between adjusted height and compression depth (p<0.001). Visual feedback attenuated the effect of height (p=0.025) on compression depth; JIT training did not (p=0.918). Visual feedback and JIT training attenuated the effect of step stool use (p<0.001) on compression depth. Step stool use is associated with improved compression depth regardless of height. Increased provider height is associated with improved compression depth, with visual feedback attenuating the effects of height and step stool use.

Cost-effective analysis of screening for biliary atresia with the stool color card.

PubMed

Mogul, Douglas; Zhou, Mo; Intihar, Paul; Schwarz, Kathleen; Frick, Kevin

2015-01-01

Biliary atresia (BA) is the leading cause of pediatric end-stage liver disease and liver transplantation in the United States. Early diagnosis leads to improved outcomes, but diagnosis is often delayed, leading to increased rates of transplantation and mortality. A Markov model was developed to simulate the natural history and transplant-related outcomes of patients with BA in a US cohort studied for 20 years. Data regarding proportions of individuals in different health states, including transplant and death, were obtained from published literature. Costs were derived from the literature and the Johns Hopkins database of charges using the cost-to-charge ratio. Strategy A represented the status quo and assumed no screening. Strategy B used nationwide screening with the stool color card developed by the Taiwan Health Bureau. The cost associated with both strategies was compared with the number of life-years gained, deaths, and the number of transplants for a 20-year interval. A dominant strategy was one that was associated with lower cost alongside improved outcomes, including increases in life-years gained, reductions in number of deaths, and reductions in number of transplants. One-way and probabilistic sensitivity analyses were performed. In strategy A, the 20-year cost was $142,479,725 with 3702 life-years, 74 deaths and 158 liver transplants. For strategy B, the cost was $133,893,563 with 3731.7 life-years, 71 deaths and 147 liver transplants. There was a >97% probability that screening with the stool color card would be cost saving and associated with an increase in life-years gained. Among all parameters, only stool color card specificity was associated with the potential for screening to no longer be cost saving. Compared with no screening, screening with the stool color card is a dominant strategy associated with lower costs and better outcomes. These findings suggest that screening with the stool color card could be an important, economically feasible

Recovery and identification of bacterial DNA from illicit drugs.

PubMed

Cho, Kaymann T; Richardson, Michelle M; Kirkbride, K Paul; McNevin, Dennis; Nelson, Michelle; Pianca, Dennis; Roffey, Paul; Gahan, Michelle E

2014-02-01

Bacterial infections, including Bacillus anthracis (anthrax), are a common risk associated with illicit drug use, particularly among injecting drug users. There is, therefore, an urgent need to survey illicit drugs used for injection for the presence of bacteria and provide valuable information to health and forensic authorities. The objectives of this study were to develop a method for the extraction of bacterial DNA from illicit drugs and conduct a metagenomic survey of heroin and methamphetamine seized in the Australian Capital Territory during 2002-2011 for the presence of pathogens. Trends or patterns in drug contamination and their health implications for injecting drug users were also investigated. Methods based on the ChargeSwitch(®)gDNA mini kit (Invitrogen), QIAamp DNA extraction mini kit (QIAGEN) with and without bead-beating, and an organic phenol/chloroform extraction with ethanol precipitation were assessed for the recovery efficiency of both free and cellular bacterial DNA. Bacteria were identified using polymerase chain reaction and electrospray ionization-mass spectrometry (PCR/ESI-MS). An isopropanol pre-wash to remove traces of the drug and diluents, followed by a modified ChargeSwitch(®) method, was found to efficiently lyse cells and extract free and cellular DNA from Gram-positive and Gram-negative bacteria in heroin and methamphetamine which could then be identified by PCR/ESI-MS. Analysis of 12 heroin samples revealed the presence of DNA from species of Comamonas, Weissella, Bacillus, Streptococcus and Arthrobacter. No organisms were detected in the nine methamphetamine samples analysed. This study develops a method to extract and identify Gram-positive and Gram-negative bacteria from illicit drugs and demonstrates the presence of a range of bacterial pathogens in seized drug samples. These results will prove valuable for future work investigating trends or patterns in drug contamination and their health implications for injecting drug

Low Cost Extraction and Isothermal Amplification of DNA for Infectious Diarrhea Diagnosis

PubMed Central

Huang, Shichu; Do, Jaephil; Mahalanabis, Madhumita; Fan, Andy; Zhao, Lei; Jepeal, Lisa; Singh, Satish K.; Klapperich, Catherine M.

2013-01-01

In order to counter the common perception that molecular diagnostics are too complicated to work in low resource settings, we have performed a difficult sample preparation and DNA amplification protocol using instrumentation designed to be operated without wall or battery power. In this work we have combined a nearly electricity-free nucleic acid extraction process with an electricity-free isothermal amplification assay to detect the presence of Clostridium difficile (C. difficile) DNA in the stool of infected patients. We used helicase-dependent isothermal amplification (HDA) to amplify the DNA in a low-cost, thermoplastic reaction chip heated with a pair of commercially available toe warmers, while using a simple Styrofoam insulator. DNA was extracted from known positive and negative stool samples. The DNA extraction protocol utilized an air pressure driven solid phase extraction device run using a standard bicycle pump. The simple heater setup required no electricity or battery and was capable of maintaining the temperature at 65°C±2°C for 55 min, suitable for repeatable HDA amplification. Experiments were performed to explore the adaptability of the system for use in a range of ambient conditions. When compared to a traditional centrifuge extraction protocol and a laboratory thermocycler, this disposable, no power platform achieved approximately the same lower limit of detection (1.25×10−2 pg of C. difficile DNA) while requiring much less raw material and a fraction of the lab infrastructure and cost. This proof of concept study could greatly impact the accessibility of molecular assays for applications in global health. PMID:23555883

Stool patterns of Malaysian adults with functional constipation: association with diet and physical activity.

PubMed

Mazlyn, Mena M; Nagarajah, Lee H L; Fatimah, A; Norimah, A K; Goh, K L

2013-04-01

Diet and lifestyle modification is commonly used in constipation management. As there is a dearth of studies on this topic in Malaysia, we aim to elucidate the relations between stool patterns, dietary intake and physical activity levels among adults with functional constipation. From a database collected via surveys at public events, a convenience sample of 100 adults diagnosed with Rome II-defined functional constipation was enrolled in this cross-sectional study. After severity assessment using the Chinese Constipation Questionnaire, subjects completed 2-week bowel movement diaries to determine stool frequency, consistency and output. Dietary intake and physical activity levels were assessed twice using three-day 24-hour diet recalls and International Physical Activity Questionnaire, respectively. Ninety subjects who completed the study were included in the analysis. Mean weekly stool frequency was 3.9 +/- 1.9 times, consistency score was 2.6 +/- 0.6 (range 1.0-4.0), output was 11.0 +/- 6.3 balls (40 mm diameter) and severity score was 10.3 +/- 3.3 (range 5.0-22.0). Mean daily dietary intakes were: energy 1,719 +/- 427kcal, dietary fibre 15.0 +/- 4.9g and fluid 2.5 +/- 0.8L. The majority of subjects were physically inactive. Stool frequency and output were positively associated with dietary fibre (r(s) = 0.278, P < 0.01; r(s) = 0.226, P < 0.05) and fluid intake (r(s) = 0.257, P < 0.05; OR = 3.571, 95% CI [1.202-10.609]). Constipation severity was associated with higher physical activity levels (OR = 2.467, 95% CI [1.054-5.777]). Insufficient intake of dietary fibre and fluid are associated with aggravated constipation symptoms. Further studies are necessary to confirm usefulness of dietary intervention in treatment of constipation as dietary factors alone may not influence overall severity and stool consistency, an integral element of constipation.

6. MOBILE LAUNCHER SIDE 4, SHOWING MILK STOOL AND LUT. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. MOBILE LAUNCHER SIDE 4, SHOWING MILK STOOL AND LUT. PROTRUSION ON UPPER RIGHT HAND SIDE OF LUT IS SWING ARM NINE WHICH PROVIDED ACCESS TO CAPSULE OF LAUNCH VEHICLE WHILE ON LAUNCHER. - Mobile Launcher One, Kennedy Space Center, Titusville, Brevard County, FL

Comparison of routine and unprepped CT colonography augmented by low fiber diet and stool tagging: a pilot study.

PubMed

Dachman, Abraham H; Dawson, Damien O; Lefere, Philippe; Yoshida, Hiro; Khan, Nasreen U; Cipriani, Nicole; Rubin, David T

2007-01-01

We performed a pilot study examining the feasibility of a new unprepped CT colonography (CTC) strategy: low fiber diet and tagging (unprepped) vs. low fiber diet, tagging and a magnesium citrate cleansing preparation (prepped). Prior reports of tagging were limited in that the residual stool was neither measured and stratified by size nor did prior reports subjectively evaluate the ease of interpretation by a reader experienced in interpreting CTC examinations. Prospective randomized to unprepped n = 14 and prepped n = 14. Colonic segments were subjectively evaluated for residual stool that would potentially interfere with interpretation. Scores were given in the following categories: percentage of residual stool that was touching or nearly touching mucosa, the largest piece of retained stool, effectiveness of tagging, height of residual fluid, degree of distention, ease of interpretation, and reading time. Ease of the CT read (scale where 4 = optimal read) averaged 1.3 for the unprepped group and 2.3 for the prepped group. The mean read time averaged 17.5 min for unprepped and 17.9 min for prepped. The degree of distention (scale where 4 = well distended) averaged 3.7 for unprepped and 3.6 for prepped. Supine and prone images combined, the unprepped group had 160 segments with stool; prepped group had 58 segments. The amount of stool covering the mucosa in all segments averaged 1.6 (33%-66% coverage) in the unprepped group and 0.35 (<33% mucosal coverage) in the prepped group. The mean size of the largest piece of stool was 33.67 mm for unprepped and 4.01 mm for prepped. Percentage of tagged stool was not significantly different between the groups (range of 94-98%). The height of residual fluid averaged 8.37 mm for unprepped and 13.4 mm for prepped. Three polyps in three patients were found during optical colonoscopy (OC) in the unprepped group (5, 6, and 10 mm), none of which were prospectively detected at CTC. Three polyps in three patients were detected during

Not Your Run-of-the-Mill Art-Room Stools

ERIC Educational Resources Information Center

Chrzanowski, Rose-Ann C.

2010-01-01

An art room should be a garden of visual stimulation, born of creativity, inquiry, critical thinking and intellectual conversation--and a little collaboration is not a bad thing either! When the author unpacked the new stools for her art room at the high school, she envisioned something more beautiful than the brown masonite circles that…

Beta-glucuronidase and Beta-glucosidase activity in stool specimens of children with inflammatory bowel disease.

PubMed

Mroczyńska, Marta; Galecka, Miroslawa; Szachta, Patrycja; Kamoda, Dorota; Libudzisz, Zdzislawa; Roszak, Dorota

2013-01-01

The aim of the study was to analyze the differences in the activity of beta-glucuronidase and beta-glucosidase in stool specimens of children with Inflammatory Bowel Diseases (IBD) and healthy subjects. The disease activity was determined according to the PCDAI scale (Crohn disease) and Truelove-Witts scale (Ulcerative colitis). Enzyme activity was determined by spectrophotometry. There was a correlation between the level of beta - glucosidase activity in stool and patient's age in the group of healthy controls, but not in the IBD group. beta-glucosidase activity in IBD and healthy subjects stool specimens did not differ significantly. The activity of beta-glucuronidase in children with IBD was two times lower than in the healthy group and was correlated with age in children with IBD, but not in the group of healthy ones.

Stool metatranscriptomics: A technical guideline for mRNA stabilisation and isolation.

PubMed

Reck, Michael; Tomasch, Jürgen; Deng, Zhiluo; Jarek, Michael; Husemann, Peter; Wagner-Döbler, Irene

2015-07-04

The complex microbiome of the gut has an enormous impact on human health. Analysis of the transcriptional activity of microorganisms through mRNA sequencing (metatranscriptomics) opens a completely new window into their activity in vivo, but it is highly challenging due to numerous technical and bioinformatical obstacles. Here we present an optimized pipeline for extraction of high quality mRNA from stool samples. Comparison of three commercially available RNA extraction kits with the method of Zoetendal revealed that the Powermicrobiome Kit (MoBio) performed best with respect to RNA yield and purity. Next, the influence of the stabilization reagent during sample storage for up to 15 days was studied. RIN analysis and qRT-PCR of spiked-in and indigenous genes revealed that RNA Later preserved mRNA integrity most efficiently, while samples conserved in RNA Protect showed substantial mRNA decay. Using the optimized pipeline developed here, recovery rates for spiked-in E.coli cells expressing fluorescing proteins were 8.7-9.7% for SuperfolderGFP and 14.7-17.8% for mCherry. The mRNA of stabilized stool samples as well as of snap-frozen controls was sequenced with Illumina Hiseq, yielding on average 74 million reads per sample. PCoA analysis, taxonomic classification using Kraken and functional classification using bwa showed that the transcriptomes of samples conserved in RNA Later were unchanged for up to 6 days even at room temperature, while RNA Protect was inefficient for storage durations exceeding 24 h. However, our data indicate that RNA Later introduces a bias which is then maintained throughout storage, while RNA Protect conserved samples are initially more similar to the snap frozen controls. RNA Later conserved samples had a reduced abundance of e.g. Prevotellaceae transcripts and were depleted for e.g. COG category "Carbohydrate transport and metabolism". Since the overall similarity between all stool transcriptional profiles studied here was >0.92, these

Preponderance of toxigenic Escherichia coli in stool pathogens correlates with toxin detection in accessible drinking-water sources.

PubMed

Igbokwe, H; Bhattacharyya, S; Gradus, S; Khubbar, M; Griswold, D; Navidad, J; Igwilo, C; Masson-Meyers, D; Azenabor, A A

2015-02-01

Since early detection of pathogens and their virulence factors contribute to intervention and control strategies, we assessed the enteropathogens in diarrhoea disease and investigated the link between toxigenic strains of Escherichia coli from stool and drinking-water sources; and determined the expression of toxin genes by antibiotic-resistant E. coli in Lagos, Nigeria. This was compared with isolates from diarrhoeal stool and water from Wisconsin, USA. The new Luminex xTAG GPP (Gastroplex) technique and conventional real-time PCR were used to profile enteric pathogens and E. coli toxin gene isolates, respectively. Results showed the pathogen profile of stool and indicated a relationship between E. coli toxin genes in water and stool from Lagos which was absent in Wisconsin isolates. The Gastroplex technique was efficient for multiple enteric pathogens and toxin gene detection. The co-existence of antibiotic resistance with enteroinvasive E. coli toxin genes suggests an additional prognostic burden on patients.

Albendazole Stimulates the Excretion of Strongyloides stercoralis Larvae in Stool Specimens and Enhances Sensitivity for Diagnosis of Strongyloidiasis▿

PubMed Central

Anamnart, Witthaya; Pattanawongsa, Attarat; Intapan, Pewpan Maleewong; Maleewong, Wanchai

2010-01-01

We succeeded in stimulation of excretion of Strongyloides stercoralis larvae in stool by oral administration of a single dose of 400 mg albendazole to strongyloidiasis patients. This result overcame the false-negative results of stool examination due to low larval numbers. Stool samples were collected from 152 asymptomatic strongyloidiasis patients in the morning, prior to eating. After breakfast, they were given a dose of 400 mg albendazole, and stool samples were collected the following morning. Agar plate culture (APC), modified formalin-ether concentration technique (MFECT), and direct-smear (DS) methods were used to examine stool specimens within 3 h after defecation. The results before and after albendazole was taken were compared. All APCs that were positive became negative after albendazole administration, while MFECT showed a 1.4- to 18.0-fold increase in larval numbers in 97.4% (148/152) of the samples. The DSs were positive in 3 out of 3 smears at a larval number of ≥45 larvae per g (lpg) of stool, and in 1or 2 out of 3 smears at a larval number between 35 and 44 lpg. At a larval number of <35 lpg, the DS became negative. Interestingly 90.5% (19/21) of the samples that were negative by all methods before albendazole administration became positive by MFECT after the treatment. Thus, MFECT can be effectively used for diagnosis of strongyloidiasis with prior administration of albendazole to the subject. PMID:20844212

Detecting an elusive invasive species: a diagnostic PCR to detect Burmese python in Florida waters and an assessment of persistence of environmental DNA.

PubMed

Piaggio, Antoinette J; Engeman, Richard M; Hopken, Matthew W; Humphrey, John S; Keacher, Kandy L; Bruce, William E; Avery, Michael L

2014-03-01

Recent studies have demonstrated that detection of environmental DNA (eDNA) from aquatic vertebrates in water bodies is possible. The Burmese python, Python bivittatus, is a semi-aquatic, invasive species in Florida where its elusive nature and cryptic coloration make its detection difficult. Our goal was to develop a diagnostic PCR to detect P. bivittatus from water-borne eDNA, which could assist managers in monitoring this invasive species. First, we used captive P. bivittatus to determine whether reptilian DNA could be isolated and amplified from water samples. We also evaluated the efficacy of two DNA isolation methods and two DNA extraction kits commonly used in eDNA preparation. A fragment of the mitochondrial cytochrome b gene from P. bivittatus was detected in all water samples isolated with the sodium acetate precipitate and the QIAamp DNA Micro Kit. Next, we designed P. bivittatus-specific primers and assessed the degradation rate of eDNA in water. Our primers did not amplify DNA from closely related species, and we found that P. bivittatus DNA was consistently detectable up to 96 h. Finally, we sampled water from six field sites in south Florida. Samples from five sites, where P. bivittatus has been observed, tested positive for eDNA. The final site was negative and had no prior documented evidence of P. bivittatus. This study shows P. bivittatus eDNA can be isolated from water samples; thus, this method is a new and promising technique for the management of invasive reptiles. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Techniques for the recovery and identification of Cryptosporidium oocysts from stool specimens.

PubMed

Garcia, L S; Bruckner, D A; Brewer, T C; Shimizu, R Y

1983-07-01

Due to increasing numbers of patients with documented infections with Cryptosporidium and other coccidia, it is important for the physician and clinical laboratory to be aware of the appropriate diagnostic techniques necessary for organism recovery and identification. Although Cryptosporidium is found in the gastrointestinal tract, tissue biopsies may be insufficient for organism recovery; the examination of stool specimens is a noninvasive procedure and will provide better overall opportunities for organism recovery. Human clinical specimens were examined from 45 patients with confirmed cryptosporidiosis or suspected of having the infection. Tissue biopsy sections, fecal wet preparations, and permanent stained smears were examined. Stool specimens were submitted in 10% Formalin, 2.5% potassium dichromate, and polyvinyl alcohol and were examined for oocysts by using 15 different methods: phase-contrast and light microscopy; Sheather's sugar flotation; Formalin concentration techniques; 10% potassium hydroxide; Giemsa; trichrome; periodic acid-Schiff; modified periodic acid-Schiff; silver methenamine; acridine orange; auramine-rhodamine; Kinyoun acid-fast; Ziehl-Neelsen carbolfuchsin; and a modified acid-fast procedure. Each technique or combination of techniques was assessed by organism quantitation, organism morphology, and ease of visual recognition. Based on these comparative studies, the modified Ziehl-Neelsen carbolfuchsin stain on 10% Formalin-preserved stool is recommended for the recovery and identification of Cryptosporidium.

Techniques for the recovery and identification of Cryptosporidium oocysts from stool specimens.

PubMed Central

Garcia, L S; Bruckner, D A; Brewer, T C; Shimizu, R Y

1983-01-01

Due to increasing numbers of patients with documented infections with Cryptosporidium and other coccidia, it is important for the physician and clinical laboratory to be aware of the appropriate diagnostic techniques necessary for organism recovery and identification. Although Cryptosporidium is found in the gastrointestinal tract, tissue biopsies may be insufficient for organism recovery; the examination of stool specimens is a noninvasive procedure and will provide better overall opportunities for organism recovery. Human clinical specimens were examined from 45 patients with confirmed cryptosporidiosis or suspected of having the infection. Tissue biopsy sections, fecal wet preparations, and permanent stained smears were examined. Stool specimens were submitted in 10% Formalin, 2.5% potassium dichromate, and polyvinyl alcohol and were examined for oocysts by using 15 different methods: phase-contrast and light microscopy; Sheather's sugar flotation; Formalin concentration techniques; 10% potassium hydroxide; Giemsa; trichrome; periodic acid-Schiff; modified periodic acid-Schiff; silver methenamine; acridine orange; auramine-rhodamine; Kinyoun acid-fast; Ziehl-Neelsen carbolfuchsin; and a modified acid-fast procedure. Each technique or combination of techniques was assessed by organism quantitation, organism morphology, and ease of visual recognition. Based on these comparative studies, the modified Ziehl-Neelsen carbolfuchsin stain on 10% Formalin-preserved stool is recommended for the recovery and identification of Cryptosporidium. Images PMID:6193138

Multicenter Comparative Evaluation of Five Commercial Methods for Toxoplasma DNA Extraction from Amniotic Fluid▿

PubMed Central

Yera, H.; Filisetti, D.; Bastien, P.; Ancelle, T.; Thulliez, P.; Delhaes, L.

2009-01-01

Over the past few years, a number of new nucleic acid extraction methods and extraction platforms using chemistry combined with magnetic or silica particles have been developed, in combination with instruments to facilitate the extraction procedure. The objective of the present study was to investigate the suitability of these automated methods for the isolation of Toxoplasma gondii DNA from amniotic fluid (AF). Therefore, three automated procedures were compared to two commercialized manual extraction methods. The MagNA Pure Compact (Roche), BioRobot EZ1 (Qiagen), and easyMAG (bioMérieux) automated procedures were compared to two manual DNA extraction kits, the QIAamp DNA minikit (Qiagen) and the High Pure PCR template preparation kit (Roche). Evaluation was carried out with two specific Toxoplasma PCRs (targeting the 529-bp repeat element), inhibitor search PCRs, and human beta-globin PCRs. The samples each consisted of 4 ml of AF with or without a calibrated Toxoplasma gondii RH strain suspension (0, 1, 2.5, 5, and 25 tachyzoites/ml). All PCR assays were laboratory-developed real-time PCR assays, using either TaqMan or fluorescent resonance energy transfer probes. A total of 1,178 PCRs were performed, including 978 Toxoplasma PCRs. The automated and manual methods were similar in sensitivity for DNA extraction from T. gondii at the highest concentration (25 Toxoplasma gondii cells/ml). However, our results showed that the DNA extraction procedures led to variable efficacy in isolating low concentrations of tachyzoites in AF samples (<5 Toxoplasma gondii cells/ml), a difference that might have repercussions since low parasite concentrations in AF exist and can lead to congenital toxoplasmosis. PMID:19846633

Quantitative Detection and Genotyping of Helicobacter pylori from Stool using Droplet Digital PCR Reveals Variation in Bacterial Loads that Correlates with cagA Virulence Gene Carriage.

PubMed

Talarico, Sarah; Safaeian, Mahboobeh; Gonzalez, Paula; Hildesheim, Allan; Herrero, Rolando; Porras, Carolina; Cortes, Bernal; Larson, Ann; Fang, Ferric C; Salama, Nina R

2016-08-01

Epidemiologic studies of the carcinogenic stomach bacterium Helicobacter pylori have been limited by the lack of noninvasive detection and genotyping methods. We developed a new stool-based method for detection, quantification, and partial genotyping of H. pylori using droplet digital PCR (ddPCR), which allows for increased sensitivity and absolute quantification by PCR partitioning. Stool-based ddPCR assays for H. pylori 16S gene detection and cagA virulence gene typing were tested using a collection of 50 matched stool and serum samples from Costa Rican volunteers and 29 H. pylori stool antigen-tested stool samples collected at a US hospital. The stool-based H. pylori 16S ddPCR assay had a sensitivity of 84% and 100% and a specificity of 100% and 71% compared to serology and stool antigen tests, respectively. The stool-based cagA genotyping assay detected cagA in 22 (88%) of 25 stools from CagA antibody-positive individuals and four (16%) of 25 stools from CagA antibody-negative individuals from Costa Rica. All 26 of these samples had a Western-type cagA allele. Presence of serum CagA antibodies was correlated with a significantly higher load of H. pylori in the stool. The stool-based ddPCR assays are a sensitive, noninvasive method for detection, quantification, and partial genotyping of H. pylori. The quantitative nature of ddPCR-based H. pylori detection revealed significant variation in bacterial load among individuals that correlates with presence of the cagA virulence gene. These stool-based ddPCR assays will facilitate future population-based epidemiologic studies of this important human pathogen. © 2015 John Wiley & Sons Ltd.

Heat-stabilised rice bran consumption by colorectal cancer survivors modulates stool metabolite profiles and metabolic networks: a randomised controlled trial.

PubMed

Brown, Dustin G; Borresen, Erica C; Brown, Regina J; Ryan, Elizabeth P

2017-05-01

Rice bran (RB) consumption has been shown to reduce colorectal cancer (CRC) growth in mice and modify the human stool microbiome. Changes in host and microbial metabolism induced by RB consumption was hypothesised to modulate the stool metabolite profile in favour of promoting gut health and inhibiting CRC growth. The objective was to integrate gut microbial metabolite profiles and identify metabolic pathway networks for CRC chemoprevention using non-targeted metabolomics. In all, nineteen CRC survivors participated in a parallel randomised controlled dietary intervention trial that included daily consumption of study-provided foods with heat-stabilised RB (30 g/d) or no additional ingredient (control). Stool samples were collected at baseline and 4 weeks and analysed using GC-MS and ultra-performance liquid chromatography-MS. Stool metabolomics revealed 93 significantly different metabolites in individuals consuming RB. A 264-fold increase in β-hydroxyisovaleroylcarnitine and 18-fold increase in β-hydroxyisovalerate exemplified changes in leucine, isoleucine and valine metabolism in the RB group. A total of thirty-nine stool metabolites were significantly different between RB and control groups, including increased hesperidin (28-fold) and narirutin (14-fold). Metabolic pathways impacted in the RB group over time included advanced glycation end products, steroids and bile acids. Fatty acid, leucine/valine and vitamin B6 metabolic pathways were increased in RB compared with control. There were 453 metabolites identified in the RB food metabolome, thirty-nine of which were identified in stool from RB consumers. RB consumption favourably modulated the stool metabolome of CRC survivors and these findings suggest the need for continued dietary CRC chemoprevention efforts.

Comparison of four DNA extraction methods for the detection of Mycobacterium leprae from Ziehl-Neelsen-stained microscopic slides.

PubMed

Ruiz-Fuentes, Jenny Laura; Díaz, Alexis; Entenza, Anayma Elena; Frión, Yahima; Suárez, Odelaisy; Torres, Pedro; de Armas, Yaxsier; Acosta, Lucrecia

2015-12-01

The diagnosis of leprosy has been a challenge due to the low sensibility of the conventional methods and the impossibility of culturing the causative organism. In this study, four methods for Mycobacterium leprae nucleic-acid extraction from Ziehl-Neelsen-stained slides (ZNS slides) were compared: Phenol/chloroform, Chelex 100 resin, and two commercial kits (Wizard Genomic DNA Purification Kit and QIAamp DNA Mini Kit). DNA was extracted from four groups of slides: a high-codification-slide group (bacteriological index [BI]⩾4), a low-codification-slide group (BI=1), a negative-slide group (BI=0), and a negative-control-slide group (BI=0). Quality DNA was evidenced by the amplification of specific repetitive element present in M. leprae genomic DNA (RLEP) using a nested polymerase chain reaction. This is the first report comparing four different extraction methods for obtaining M. leprae DNA from ZNS slides in Cuban patients, and applied in molecular diagnosis. Good-quality DNA and positive amplification were detected in the high-codification-slide group with the four methods, while from the low-codification-slide group only the QIAGEN and phenol-chloroform methods obtained amplification of M. leprae. In the negative-slide group, only the QIAGEN method was able to obtain DNA with sufficient quality for positive amplification of the RLEP region. No amplification was observed in the negative-control-slide group by any method. Patients with ZNS negative slides can still transmit the infection, and molecular methods can help identify and treat them, interrupting the chain of transmission and preventing the onset of disabilities. The ZNS slides can be sent easily to reference laboratories for later molecular analysis that can be useful not only to improve the diagnosis, but also for the application of other molecular techniques. Copyright © 2015 Asian-African Society for Mycobacteriology. Published by Elsevier Ltd. All rights reserved.

Evaluation of Methods to Improve the Extraction and Recovery of DNA from Cotton Swabs for Forensic Analysis

PubMed Central

Adamowicz, Michael S.; Stasulli, Dominique M.; Sobestanovich, Emily M.; Bille, Todd W.

2014-01-01

Samples for forensic DNA analysis are often collected from a wide variety of objects using cotton or nylon tipped swabs. Testing has shown that significant quantities of DNA are retained on the swab, however, and subsequently lost. When processing evidentiary samples, the recovery of the maximum amount of available DNA is critical, potentially dictating whether a usable profile can be derived from a piece of evidence or not. The QIAamp DNA Investigator extraction kit was used with its recommended protocol for swabs (one hour incubation at 56°C) as a baseline. Results indicate that over 50% of the recoverable DNA may be retained on the cotton swab tip, or otherwise lost, for both blood and buccal cell samples when using this protocol. The protocol’s incubation time and temperature were altered, as was incubating while shaking or stationary to test for increases in recovery efficiency. An additional step was then tested that included periodic re-suspension of the swab tip in the extraction buffer during incubation. Aliquots of liquid blood or a buccal cell suspension were deposited and dried on cotton swabs and compared with swab-less controls. The concentration of DNA in each extract was quantified and STR analysis was performed to assess the quality of the extracted DNA. Stationary incubations and those performed at 65°C did not result in significant gains in DNA yield. Samples incubated for 24 hours yielded less DNA. Increased yields were observed with three and 18 hour incubation periods. Increases in DNA yields were also observed using a swab re-suspension method for both cell types. The swab re-suspension method yielded an average two-fold increase in recovered DNA yield with buccal cells and an average three-fold increase with blood cells. These findings demonstrate that more of the DNA collected on swabs can be recovered with specific protocol alterations. PMID:25549111

Heat-stabilised rice bran consumption by colorectal cancer survivors modulates stool metabolite profiles and metabolic networks: a randomised controlled trial

PubMed Central

Brown, Dustin G.; Borresen, Erica C.; Brown, Regina J.; Ryan, Elizabeth P.

2017-01-01

Rice bran (RB) consumption has been shown to reduce colorectal cancer (CRC) growth in mice and modify the human stool microbiome. Changes in host and microbial metabolism induced by RB consumption was hypothesised to modulate the stool metabolite profile in favour of promoting gut health and inhibiting CRC growth. The objective was to integrate gut microbial metabolite profiles and identify metabolic pathway networks for CRC chemoprevention using non-targeted metabolomics. In all, nineteen CRC survivors participated in a parallel randomised controlled dietary intervention trial that included daily consumption of study-provided foods with heat-stabilised RB (30 g/d) or no additional ingredient (control). Stool samples were collected at baseline and 4 weeks and analysed using GC-MS and ultra-performance liquid chromatography-MS. Stool metabolomics revealed 93 significantly different metabolites in individuals consuming RB. A 264-fold increase in β-hydroxyisovaleroylcarnitine and 18-fold increase in β-hydroxyisovalerate exemplified changes in leucine, isoleucine and valine metabolism in the RB group. A total of thirty-nine stool metabolites were significantly different between RB and control groups, including increased hesperidin (28-fold) and narirutin (14-fold). Metabolic pathways impacted in the RB group over time included advanced glycation end products, steroids and bile acids. Fatty acid, leucine/valine and vitamin B6 metabolic pathways were increased in RB compared with control. There were 453 metabolites identified in the RB food metabolome, thirty-nine of which were identified in stool from RB consumers. RB consumption favourably modulated the stool metabolome of CRC survivors and these findings suggest the need for continued dietary CRC chemoprevention efforts. PMID:28643618

Development of an Efficient Entire-Capsid-Coding-Region Amplification Method for Direct Detection of Poliovirus from Stool Extracts

PubMed Central

Kilpatrick, David R.; Nakamura, Tomofumi; Burns, Cara C.; Bukbuk, David; Oderinde, Soji B.; Oberste, M. Steven; Kew, Olen M.; Pallansch, Mark A.; Shimizu, Hiroyuki

2014-01-01

Laboratory diagnosis has played a critical role in the Global Polio Eradication Initiative since 1988, by isolating and identifying poliovirus (PV) from stool specimens by using cell culture as a highly sensitive system to detect PV. In the present study, we aimed to develop a molecular method to detect PV directly from stool extracts, with a high efficiency comparable to that of cell culture. We developed a method to efficiently amplify the entire capsid coding region of human enteroviruses (EVs) including PV. cDNAs of the entire capsid coding region (3.9 kb) were obtained from as few as 50 copies of PV genomes. PV was detected from the cDNAs with an improved PV-specific real-time reverse transcription-PCR system and nucleotide sequence analysis of the VP1 coding region. For assay validation, we analyzed 84 stool extracts that were positive for PV in cell culture and detected PV genomes from 100% of the extracts (84/84 samples) with this method in combination with a PV-specific extraction method. PV could be detected in 2/4 stool extract samples that were negative for PV in cell culture. In PV-positive samples, EV species C viruses were also detected with high frequency (27% [23/86 samples]). This method would be useful for direct detection of PV from stool extracts without using cell culture. PMID:25339406

Novel Stool-Based Protein Biomarkers for Improved Colorectal Cancer Screening: A Case-Control Study.

PubMed

Bosch, Linda J W; de Wit, Meike; Pham, Thang V; Coupé, Veerle M H; Hiemstra, Annemieke C; Piersma, Sander R; Oudgenoeg, Gideon; Scheffer, George L; Mongera, Sandra; Sive Droste, Jochim Terhaar; Oort, Frank A; van Turenhout, Sietze T; Larbi, Ilhame Ben; Louwagie, Joost; van Criekinge, Wim; van der Hulst, Rene W M; Mulder, Chris J J; Carvalho, Beatriz; Fijneman, Remond J A; Jimenez, Connie R; Meijer, Gerrit A

2017-12-19

The fecal immunochemical test (FIT) for detecting hemoglobin is used widely for noninvasive colorectal cancer (CRC) screening, but its sensitivity leaves room for improvement. To identify novel protein biomarkers in stool that outperform or complement hemoglobin in detecting CRC and advanced adenomas. Case-control study. Colonoscopy-controlled referral population from several centers. 315 stool samples from one series of 12 patients with CRC and 10 persons without colorectal neoplasia (control samples) and a second series of 81 patients with CRC, 40 with advanced adenomas, and 43 with nonadvanced adenomas, as well as 129 persons without colorectal neoplasia (control samples); 72 FIT samples from a third independent series of 14 patients with CRC, 16 with advanced adenomas, and 18 with nonadvanced adenomas, as well as 24 persons without colorectal neoplasia (control samples). Stool samples were analyzed by mass spectrometry. Classification and regression tree (CART) analysis and logistic regression analyses were performed to identify protein combinations that differentiated CRC or advanced adenoma from control samples. Antibody-based assays for 4 selected proteins were done on FIT samples. In total, 834 human proteins were identified, 29 of which were statistically significantly enriched in CRC versus control stool samples in both series. Combinations of 4 proteins reached sensitivities of 80% and 45% for detecting CRC and advanced adenomas, respectively, at 95% specificity, which was higher than that of hemoglobin alone (P < 0.001 and P = 0.003, respectively). Selected proteins could be measured in small sample volumes used in FIT-based screening programs and discriminated between CRC and control samples (P < 0.001). Lack of availability of antibodies prohibited validation of the top protein combinations in FIT samples. Mass spectrometry of stool samples identified novel candidate protein biomarkers for CRC screening. Several protein combinations outperformed

Digestion-resistant maltodextrin effects on colonic transit time and stool weight: a randomized controlled clinical study.

PubMed

Abellán Ruiz, María Salud; Barnuevo Espinosa, María Dolores; Contreras Fernández, Carlos J; Luque Rubia, Antonio J; Sánchez Ayllón, Francisca; Aldeguer García, Miriam; García Santamaría, Carlos; López Román, Francisco Javier

2016-12-01

Increased awareness of the importance of dietary fibre has led to increased interest in "functional" fibre components like digestion-resistant maltodextrin (RMD). This randomized, placebo-controlled, double-blind study assessed the effects of RMD in the colonic transit time (CTT) and defecation characteristics (frequency, stool volume and consistency). Sixty-six healthy adult volunteers (32 men) who did not have a daily defecation habit had a 7-day run-in period before the 21-day intervention period with RMD or placebo. CTT and segmental CTT (SCTT) were assessed by a single abdominal X-ray film taken at the end of both periods after radiopaque marker ingestion. Defecation characteristics and intestinal functions were also assessed, which were self-reported by patients. Intragroup comparisons were evaluated by Student's paired t test, Bonferroni test and Chi-square test, while time comparisons by analysis of variance (ANOVA) and time-by-treatment interaction by repeated-measures ANOVA. Fifty-seven subjects were assessed for CTT (placebo, n = 28; RMD, n = 29). In the RMD group, the total CTT, left SCTT and rectosigmoidal SCTT decreased significantly compared to baseline (p < 0.01 each; -13.3, -4.7, -8.7 h, respectively). Significant differences between groups were observed in total CTT and left SCTT. Significant time-by-treatment interaction was observed in the RMD group for stool volume (p = 0.014), increasing 56 % compared to baseline (p < 0.01), while remained unchanged in the placebo group. Stool consistency was improved only in the RMD group (p < 0.01). No adverse effects related to study products were observed. The results show that RMD improved CTT, stool volume, stool consistency and some intestinal functions in a healthy population.

The complete genome of klassevirus – a novel picornavirus in pediatric stool

PubMed Central

Greninger, Alexander L; Runckel, Charles; Chiu, Charles Y; Haggerty, Thomas; Parsonnet, Julie; Ganem, Donald; DeRisi, Joseph L

2009-01-01

Background Diarrhea kills 2 million children worldwide each year, yet an etiological agent is not found in approximately 30–50% of cases. Picornaviral genera such as enterovirus, kobuvirus, cosavirus, parechovirus, hepatovirus, teschovirus, and cardiovirus have all been found in human and animal diarrhea. Modern technologies, especially deep sequencing, allow rapid, high-throughput screening of clinical samples such as stool for new infectious agents associated with human disease. Results A pool of 141 pediatric gastroenteritis samples that were previously found to be negative for known diarrheal viruses was subjected to pyrosequencing. From a total of 937,935 sequence reads, a collection of 849 reads distantly related to Aichi virus were assembled and found to comprise 75% of a novel picornavirus genome. The complete genome was subsequently cloned and found to share 52.3% nucleotide pairwise identity and 38.9% amino acid identity to Aichi virus. The low level of sequence identity suggests a novel picornavirus genus which we have designated klassevirus. Blinded screening of 751 stool specimens from both symptomatic and asymptomatic individuals revealed a second positive case of klassevirus infection, which was subsequently found to be from the index case's 11-month old twin. Conclusion We report the discovery of human klassevirus 1, a member of a novel picornavirus genus, in stool from two infants from Northern California. Further characterization and epidemiological studies will be required to establish whether klasseviruses are significant causes of human infection. PMID:19538752

Habitual dietary intake is associated with stool microbiota composition in monozygotic twins.

PubMed

Simões, Catarina D; Maukonen, Johanna; Kaprio, Jaakko; Rissanen, Aila; Pietiläinen, Kirsi H; Saarela, Maria

2013-04-01

The impact of diet on the gut microbiota has usually been assessed by subjecting people to the same controlled diet and thereafter following the shifts in the microbiota. In the present study, we used habitual dietary intake, clinical data, quantitative polymerase chain reaction, and denaturing gradient gel electrophoresis (DGGE) to characterize the stool microbiota of Finnish monozygotic twins. The effect of diet on the numbers of bacteria was described through a hierarchical linear mixed model that included the twin individuals, stratified by body mass index, and their families as random effects. The abundance and diversity of the bacterial groups studied did not differ between normal-weight, overweight, and obese individuals with the techniques used. Intakes of energy, monounsaturated fatty acids, n3 polyunsaturated fatty acids (PUFAs), n6 PUFAs, and soluble fiber had significant associations with the stool bacterial numbers (e.g., increased energy intake was associated with reduced numbers of Bacteroides spp.). In addition, co-twins with identical energy intake had more similar numbers and DGGE-profile diversities of Bacteroides spp. than did the co-twins with different intake. Moreover, the co-twins who ingested the same amounts of saturated fatty acids had very similar DGGE profiles of Bacteroides spp., whereas the co-twins with similar consumption of fiber had a very low bifidobacterial DGGE-profile similarity. In conclusion, our findings confirm that the diet plays an important role in the modulation of the stool microbiota, in particular Bacteroides spp. and bifidobacteria.

Development of an efficient entire-capsid-coding-region amplification method for direct detection of poliovirus from stool extracts.

PubMed

Arita, Minetaro; Kilpatrick, David R; Nakamura, Tomofumi; Burns, Cara C; Bukbuk, David; Oderinde, Soji B; Oberste, M Steven; Kew, Olen M; Pallansch, Mark A; Shimizu, Hiroyuki

2015-01-01

Laboratory diagnosis has played a critical role in the Global Polio Eradication Initiative since 1988, by isolating and identifying poliovirus (PV) from stool specimens by using cell culture as a highly sensitive system to detect PV. In the present study, we aimed to develop a molecular method to detect PV directly from stool extracts, with a high efficiency comparable to that of cell culture. We developed a method to efficiently amplify the entire capsid coding region of human enteroviruses (EVs) including PV. cDNAs of the entire capsid coding region (3.9 kb) were obtained from as few as 50 copies of PV genomes. PV was detected from the cDNAs with an improved PV-specific real-time reverse transcription-PCR system and nucleotide sequence analysis of the VP1 coding region. For assay validation, we analyzed 84 stool extracts that were positive for PV in cell culture and detected PV genomes from 100% of the extracts (84/84 samples) with this method in combination with a PV-specific extraction method. PV could be detected in 2/4 stool extract samples that were negative for PV in cell culture. In PV-positive samples, EV species C viruses were also detected with high frequency (27% [23/86 samples]). This method would be useful for direct detection of PV from stool extracts without using cell culture. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Long-term Shedding of Influenza A Virus in Stool of Immunocompromised Child

PubMed Central

Mix, Samantha; Rowe, Judy; Ikemoto, Sheryl; Baron, Ellen J.

2010-01-01

In immunocompromised patients, influenza infection may progress to prolonged viral shedding from the respiratory tract despite antiviral therapy. We describe chronic influenza A virus infection in an immunocompromised child who had prolonged shedding of culturable influenza virus in stool. PMID:20587197

Prevalence of multi-drug resistant organisms in stool of paediatric patients with acute leukaemia and correlation with blood culture positivity: A single institution experience.

PubMed

Shankar, Krupa; Radhakrishnan, Venkatraman; Vijayakumar, Varalakskmi; Ramamoorthy, Jaikumar; Ganesan, Prasanth; Dhanushkodi, Manikandan; Ganesan, T S; Sagar, T G

2018-01-01

Multi-drug resistant (MDR) bacteria are associated with increased morbidity and mortality in children with acute leukaemia. The present study was conducted to assess the prevalence of MDR bacteria in stool cultures of patients with acute leukaemia at presentation to the hospital. The results were then correlated with blood cultures when patients developed septicaemia. The study involved analysis of case records of patients with newly diagnosed acute leukaemia less than 18 years of age treated at our centre from January 2015 to December 2015. Stool cultures were sent within 72 hr of hospital admission and blood cultures were sent when clinically indicated. MDR was defined as resistance to at least one antibiotic in three or more following antimicrobial groups: cephalosporins, β-lactam/β-lactamase inhibitor, carbapenems, fluoroquinolones and aminoglycosides. The analysis included 85 patients with acute leukaemia, among whom 48 of 85 (56%) patients had positive stool cultures and 42 of 85 (50%) patients were positive for MDR bacteria. Blood cultures were positive in 13 of 48 patients (27%, seven MDR and six non-MDR) with positive stool cultures and three of 37 patients (8%, one MDR and two non-MDR) with negative stool cultures (P = 0.01). The concordance between stool and blood culture for similar organism was 61%. There were seven deaths in 48 stool culture positive patients and two deaths in 37 stool culture negative patients. This study shows the high prevalence of MDR bacteria in newly diagnosed children with acute leukaemia. Colonisation with MDR bacteria in stools is associated with increased positivity of blood cultures and mortality. © 2017 Wiley Periodicals, Inc.

High frequency of parasitic and viral stool pathogens in patients with active ulcerative colitis: report from a tropical country.

PubMed

Banerjee, Debabrata; Deb, Rachana; Dar, Lalit; Mirdha, Bijay R; Pati, Sunil K; Thareja, Sandeep; Falodia, Sushil; Ahuja, Vineet

2009-01-01

Diarrhoeal relapses in patients with ulcerative colitis (UC) may be associated with enteric infections and its diagnosis may lessen avoidable exposure to corticosteroids and/or immunosuppressants. The purpose of this study was to assess the frequency of stool pathogens (parasitic and viral) in patients with active UC. This prospective cross-sectional study included 49 consecutive patients (32 M, 17 F, mean age 35.8+/-12 years) with active UC. Three stool samples were collected from each patient and examined for parasitic infection. Rectal biopsies were obtained during sigmoidoscopy to demonstrate cytomegalovirus (CMV) inclusion bodies and to conduct qualitative polymerase chain reaction (PCR) for CMV and herpes simplex virus (HSV) DNA detection. Median duration of illness was 3.9+/-3.7 years and 83.7% of the patients had moderate to severe disease. The prevalence of parasitic infections in UC was 12%. The organisms isolated were Strongyloides stercoralis in 4%, Ankylostoma duodenale in 4%, Cryptosporidium in 2% and Entamoeba histolytica in 2% of the patients. The prevalence of CMV and HSV in rectal biopsies using qualitative PCR was 8% and 10%, respectively. No predictive factor was identified with CMV superinfection in patients with active UC. In India there is a high prevalence of parasitic and viral infections in patients with active UC. The results of the study suggest that, in tropical countries with a known high prevalence of parasitic diseases, aggressive evaluation for parasitic and viral infections should be carried out, as early identification and prompt treatment of such infections can improve the clinical course of patients with active UC.

Results of a 6-month survey of stool cultures for Escherichia coli O157:H7.

PubMed

Marshall, W F; McLimans, C A; Yu, P K; Allerberger, F J; Van Scoy, R E; Anhalt, J P

1990-06-01

Escherichia coli O157:H7 is a recently recognized enteric pathogen that causes acute hemorrhagic colitis. Although the infection is usually self-limited, it may be complicated by hemolytic uremic syndrome and thrombotic thrombocytopenic purpura. At our institution, stool specimens are now routinely cultured for this organism. To determine the prevalence of E. coli O157:H7-associated diarrhea in our patient population, we surveyed all submitted stool cultures for 6 months for this organism. Specimens were screened for non-sorbitol fermenting E. coli and confirmed by slide-agglutination and immobilization testing. Of 2,164 specimens, 10 yielded E. coli O157:H7. It was the fourth most common bacterial stool pathogen found. Bloody diarrhea and abdominal pain were the most common symptoms of the infected patients. E. coli O157:H7 causes sporadic infections in our patient population and should be considered in the differential diagnosis of acute hemorrhagic colitis.

In vitro growth of Vibrio cholerae in cholera stool fluid leads to differential expression of virulence factors.

PubMed

Sánchez, J; Castillo, G; Medrano, A I; Martinez-Palomo, A; Rodríguez, M H

1995-01-01

We report on the physiological response of Vibrio cholerae upon growth on bacteria-free intestinal fluids prepared from feces of individuals in the acute phase of cholera. Sterilized stool fluids supported growth of V. cholerae to reach 0.3-0.4 O.D. units (600 nm) at 37 degrees C. Scanning electron microscopy showed vibrios to be slender and elongated as compared to bacteria in synthetic media. Growth in stool fluid apparently induced expression of several immunoreactive proteins using cholera convalescent sera. Supernatants of fluid-grown vibrios had undetectable cholera toxin (CT) concentrations. Soluble hemagglutinins and soluble proteases were much less reduced when compared to cultures in Syncase or AKI media while cell-associated mannose-sensitive hemagglutinin (MSHA) was expressed at good levels. Lack of production of CT in fluid devoid of tissue may be due to absence of stimulating elements in intact intestine. Alternatively, culturing V. cholerae in stool fluid might resemble a late proliferation stage where downregulation of toxin might occur. Irrespectively, concomitant production of other virulence factors represents a phenomenon of differential regulation by fluid. Efforts are now underway to determine if this response depends upon factors in stool fluid acting through known genetic regulatory cascades or other. Attempts are also geared to identify fluid-induced proteins and their genes.

Evaluation of stool microbiota signatures in two cohorts of Asian (Singapore and Indonesia) newborns at risk of atopy

PubMed Central

2011-01-01

Background Studies have suggested that demographic and lifestyle factors could shape the composition of fecal microbiota in early life. This study evaluated infant stool microbiota signatures in two Asian populations, Singapore (n = 42) and Indonesia (n = 32) with contrasting socioeconomic development, and examined the putative influences of demographic factors on these human fecal associated bacterial signatures. Results Longitudinal analysis showed associations of geographical origin with Clostridium leptum, Atopobium and Bifidobacterium groups. Mode of delivery had the largest effect on stool microbiota signatures influencing the abundance of four bacterial groups. Significantly higher abundance of bacterial members belonging to the Bacteroides-Prevotella, Bifidobacterium and Atopobium groups, but lower abundance of Lactobacilli-Enterococci group members, were observed in vaginal delivered compared to caesarean delivered infants. Demographic factors influencing the structure of infants stool microbiota during the first year of life included breastfeeding, age of weaning, sibship size and exposure to antibiotics. Conclusions Differences in stool microbiota signatures were observed in relation to various demographic factors. These features may confound studies relating to the association of the structure of fecal microbiota and the predisposition to human modern disease. PMID:21875444

Feasibility of introducing rejection criteria for stool cultures in a teaching hospital in Portugal.

PubMed

Hänscheid, T; Cristino, J M; Salgado, M J

2002-02-01

The possible introduction of rejection criteria for stool cultures (stool culture (adults 9.7%, pediatric 21.7%). Eighty-five percent had

Xpert MTB/RIF diagnosis of childhood tuberculosis from sputum and stool samples in a high TB-HIV-prevalent setting.

PubMed

Orikiriza, Patrick; Nansumba, Margaret; Nyehangane, Dan; Bastard, Mathieu; Mugisha, Ivan Taremwa; Nansera, Denis; Mwanga-Amumpaire, Juliet; Boum, Yap; Kumbakumba, Elias; Bonnet, Maryline

2018-05-08

The Xpert MTB/RIF assay is a major advance for diagnosis of tuberculosis (TB) in high-burden countries but is limited in children by their difficulty to produce sputum. We investigated TB in sputum and stool from children with the aim of improving paediatric TB diagnosis. A prospective cohort of children with presumptive TB, provided two sputum or induced sputum at enrolment in a regional referral hospital in Uganda. Stool was collected from those started on TB treatment. All specimen were tested for Xpert MTB/RIF, mycobacteria growth indicator tube (MGIT), Lowenstein Jensen cultures and microscopy (except stool). We compared TB detection between age categories and assessed the performance of Xpert MTB/RIF in sputum and stool. Of the 392 children enrolled, 357 (91.1%) produced at least one sputum sample. Sputum culture yield was 13/357 (3.6%): 3/109 (2.6%), 3/89 (3.2%), 3/101 (2.6%) and 4/44 (8.2%) among children of < 2, 2-5, ≥ 5-10 and > 10 years, respectively (p = 0.599). Xpert MTB/RIF yield was 14/350 (4.0%): 3/104 (2.9%), 4/92 (4.3%), 3/88 (2.9%) and 4/50 (.0%), respectively (p = 0.283). Sensitivity and specificity of Xpert MTB/RIF in sputum against sputum culture were 90.9% (95% CI 58.7-99.8) and 99.1% (99.1-99.8). In stool, it was 55.6% (21.2-86.3) and 98.2% (98.2-100) against Xpert MTB/RIF and culture in sputum. Only a minority of children had microbiologically confirmed TB with a higher proportion in children above 10 years. Although sensitivity of Xpert MTB/RIF in stool was low, with good optimization, it might be a good alternative to sputum in children.

Is PCR the Next Reference Standard for the Diagnosis of Schistosoma in Stool? A Comparison with Microscopy in Senegal and Kenya.

PubMed

Meurs, Lynn; Brienen, Eric; Mbow, Moustapha; Ochola, Elizabeth A; Mboup, Souleymane; Karanja, Diana M S; Secor, W Evan; Polman, Katja; van Lieshout, Lisette

2015-01-01

The current reference test for the detection of S. mansoni in endemic areas is stool microscopy based on one or more Kato-Katz stool smears. However, stool microscopy has several shortcomings that greatly affect the efficacy of current schistosomiasis control programs. A highly specific multiplex real-time polymerase chain reaction (PCR) targeting the Schistosoma internal transcriber-spacer-2 sequence (ITS2) was developed by our group a few years ago, but so far this PCR has been applied mostly on urine samples. Here, we performed more in-depth evaluation of the ITS2 PCR as an alternative method to standard microscopy for the detection and quantification of Schistosoma spp. in stool samples. Microscopy and PCR were performed in a Senegalese community (n = 197) in an area with high S. mansoni transmission and co-occurrence of S. haematobium, and in Kenyan schoolchildren (n = 760) from an area with comparatively low S. mansoni transmission. Despite the differences in Schistosoma endemicity the PCR performed very similarly in both areas; 13-15% more infections were detected by PCR when comparing to microscopy of a single stool sample. Even when 2-3 stool samples were used for microscopy, PCR on one stool sample detected more infections, especially in people with light-intensity infections and in children from low-risk schools. The low prevalence of soil-transmitted helminthiasis in both populations was confirmed by an additional multiplex PCR. The ITS2-based PCR was more sensitive than standard microscopy in detecting Schistosoma spp. This would be particularly useful for S. mansoni detection in low transmission areas, and post-control settings, and as such improve schistosomiasis control programs, epidemiological research, and quality control of microscopy. Moreover, it can be complemented with other (multiplex real-time) PCRs to detect a wider range of helminths and thus enhance effectiveness of current integrated control and elimination strategies for neglected

Human DNA extraction from whole saliva that was fresh or stored for 3, 6 or 12 months using five different protocols

PubMed Central

GARBIERI, Thais Francini; BROZOSKI, Daniel Thomas; DIONÍSIO, Thiago José; SANTOS, Carlos Ferreira; NEVES, Lucimara Teixeira das

2017-01-01

Abstract Saliva when compared to blood collection has the following advantages: it requires no specialized personnel for collection, allows for remote collection by the patient, is painless, well accepted by participants, has decreased risks of disease transmission, does not clot, can be frozen before DNA extraction and possibly has a longer storage time. Objective and Material and Methods This study aimed to compare the quantity and quality of human DNA extracted from saliva that was fresh or frozen for three, six and twelve months using five different DNA extraction protocols: protocol 1 – Oragene™ commercial kit, protocol 2 – QIAamp DNA mini kit, protocol 3 – DNA extraction using ammonium acetate, protocol 4 – Instagene™ Matrix and protocol 5 – Instagene™ Matrix diluted 1:1 using proteinase K and 1% SDS. Briefly, DNA was analyzed using spectrophotometry, electrophoresis and PCR. Results Results indicated that time spent in storage typically decreased the DNA quantity with the exception of protocol 1. The purity of DNA was generally not affected by storage times for the commercial based protocols, while the purity of the DNA samples extracted by the noncommercial protocols typically decreased when the saliva was stored longer. Only protocol 1 consistently extracted unfragmented DNA samples. In general, DNA samples extracted through protocols 1, 2, 3 and 4, regardless of storage time, were amplified by human specific primers whereas protocol 5 produced almost no samples that were able to be amplified by human specific primers. Depending on the protocol used, it was possible to extract DNA in high quantities and of good quality using whole saliva, and furthermore, for the purposes of DNA extraction, saliva can be reliably stored for relatively long time periods. Conclusions In summary, a complicated picture emerges when taking into account the extracted DNA’s quantity, purity and quality; depending on a given researchers needs, one protocol�

Identification of Giardia lamblia and the human infectious-species of Cryptosporidium in drinking water resources in Western Saudi Arabia by nested-PCR assays.

PubMed

Hawash, Y; Ghonaim, M; Hussein, Y; Alhazmi, A; Alturkistani, A

2015-06-01

The presence of Cryptosporidium and/or Giardia in drinking water represents a major public health problem. This study was the first report concerned with the occurrence of these protozoa in drinking water in Saudi Arabia. The study was undertaken in Al-Taif, a high altitude region, Western Saudi Arabia. Eight underground wells water, six desalinated water and five domestic brands of bottled water samples, 10 liter each, were monthly collected between May 2013 and April 2014. All samples (n = 228), were processed using an automated wash/elution station (IDEXX Laboratories, Inc.). Genomic DNA was directly isolated and purified from samples concentrates with QIAamp® Stool Mini Kit (Qiagen). The target protozoan DNA sequences were amplified using two previously published nested-PCR protocols. Of all the analyzed water, 31 samples (≈14%) were found contaminated with the target protozoa. Giardia lamblia was detected in ≈10% (7/72) of desalinated water and in ≈9% (9/96) of wells water. On the other hand, Cryptosporidium was identified in ≈8% (8/72) of desalinated water and in ≈7% (7/96) of wells water. All bottled water samples (n = 60) were (oo)cysts-free. Protozoan (oo)cysts were more frequently identified in water samples collected in the spring than in other seasons. The methodology established in our study proved sensitive, cost-effective and is amenable for future automation or semi-automation. For better understanding of the current situation that represent an important health threat to the local inhabitants, further studies concerned with (oo)cyst viability, infectivity, concentration and genotype identification are recommended.

Evaluation of Streck BCT and PAXgene Stabilised Blood Collection Tubes for Cell-Free Circulating DNA Studies in Plasma.

PubMed

Warton, Kristina; Yuwono, Nicole L; Cowley, Mark J; McCabe, Mark J; So, Alwin; Ford, Caroline E

2017-10-01

Blood samples for studies of circulating DNA in disease are often collected in clinical settings where prompt processing of samples is not possible. In order to avoid problems associated with leukocyte lysis after prolonged blood storage, stabilised blood tubes have been developed containing preservatives that prevent cell lysis. We evaluated Streck BCT tubes and PAXgene ccfDNA tubes, as well as standard EDTA blood collection tubes, in terms of DNA yield and fragment size. Blood was collected in EDTA, Streck BCT or PAXgene ccfDNA tubes and stored for 1 h at 4 °C, or 4 days at room temperature. DNA was extracted using the QIAamp Circulating Nucleic Acids kit, and visualised on an agarose gel or quantitated by qPCR. Ratios of a 247-base and a 115-base amplicon of the Alu repetitive element were used to infer size distribution. While plasma DNA in EDTA tube blood samples increased by ~10- to 20-fold after 4 days of storage at room temperature, both Streck BCT tubes and PAXgene ccfDNA tubes maintained stable plasma DNA concentrations. A slight decrease in DNA yield following 1 h of blood storage at 4 °C was observed in Streck BCT and PAXgene ccfDNA tubes relative to EDTA tubes. This decrease was reversed by increasing the proteinase digest step of the DNA extraction protocol to 60 min, as recommended by Streck tube product literature. Visualisation of the extracted DNA on an agarose gel showed that after 4 days of room temperature storage, samples collected in EDTA tubes contained abundant high-molecular weight DNA, which was partially fragmented in a ladder pattern. A slight increase in high-molecular weight DNA in samples stored for 4 days at room temperature in Streck BCT tubes was also observed, but this was not reflected in a change in large and small Alu fragment ratios as measured by qPCR. Tubes containing preservative to prevent cell lysis can extend the scope for blood collection in clinical settings; however, slight differences between samples

Cell-free mitochondrial DNA copy number variation in head and neck squamous cell carcinoma: A study of non-invasive biomarker from Northeast India.

PubMed

Kumar, Manish; Srivastava, Shilpee; Singh, Seram Anil; Das, Anup Kumar; Das, Ganesh Chandra; Dhar, Bishal; Ghosh, Sankar Kumar; Mondal, Rosy

2017-10-01

Head and neck squamous cell carcinoma is the most commonly diagnosed cancer worldwide. The lifestyle, food habits, and customary practices manifest the Northeast Indian population toward higher susceptibility to develop head and neck squamous cell carcinoma. Here, we have investigated the association of smoke and smokeless tobacco, and alcohol with copy number variation of cell-free mitochondrial DNA and cell-free nuclear DNA in cases and controls. Cell-free DNA from plasma was isolated from 50 head and neck squamous cell carcinoma cases and 50 controls with informed written consent using QIAamp Circulating Nucleic Acid Kit. Real-time polymerase chain reaction was done for copy number variation in cell-free mitochondrial DNA and cell-free nuclear DNA. Receiver operating characteristic curve analysis was performed to evaluate the diagnostic application between the two study groups using clinicopathological parameters. The levels of cell-free nuclear DNA and cell-free mitochondrial DNA of cases in association with smoke and smokeless tobacco, alcohol with smoking (p < 0.05) were significantly higher (p < 0.01 and p < 0.001, respectively) than controls. Using receiver operating characteristic curve analysis between head and neck squamous cell carcinoma cases and controls, we distinguished cell-free mitochondrial DNA (cutoff: 19.84 raw Ct; sensitivity: 84%; specificity: 100%; p < 0.001) and cell-free nuclear DNA (cutoff: 463,282 genomic equivalent/mL; sensitivity: 53%; specificity: 87%; p < 0.001). The copy number variation in cases (cell-free nuclear DNA: 5451.66 genomic equivalent/mL and cell-free mitochondrial DNA: 29,103,476.15 genomic equivalent/mL) and controls (cell-free nuclear DNA: 1650.9 genomic equivalent/mL and cell-free mitochondrial DNA: 9,189,312.54 genomic equivalent/mL), respectively. Our result indicates that the cell-free mitochondrial DNA content is highly associated with smoke and smokeless tobacco, betel quid chewing

Reliability of a new technique for the determination of vitamin B12 absorption in children: single stool sample test--a double isotope technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hjelt, K.

1986-03-01

The fractional vitamin B12 absorption (FAB12) was determined in 39 patients with various gastrointestinal diseases by a double-isotope technique, employing a single stool sample test (SSST), as well as a complete stool collection. The age of the patients ranged from 2.5 months to 16.2 years (mean 5.0 years). The test dose was administered orally and consisted of 0.5-4.5 micrograms of /sup 57/CoB12 (approximately 0.05 microCi), carmine powder, and 2 mg /sup 51/CrCl/sub 3/ (approximately 1.25 microCi) as the inabsorbable tracer. The wholebody radiation to a 1-year-old child averaged only 20 mrad. The stool and napkin was collected and homogenized bymore » addition of 300 ml chromium sulfuric acid. A 300-ml sample of the homogenized stool and napkin, as well as 300 ml chromium sulfuric acid (75% v/v) containing the standards, were counted in a broad-based well counter. The FAB12 determined by SSST employing the stool with the highest content of /sup 51/Cr (which corresponded to the most carmine-colored stool) correlated closely to the FAB12 based on complete stool collection (r = 0.98, n = 39, p less than 0.001). The reproducibility of FAB12 determined by SSST was assessed from double assays in 19 patients. For a mean value of 12%, the SD was 3%, which corresponded to a coefficient of variation (CV) of 25%. The excretion of /sup 57/Co and /sup 51/Cr in the urine was examined in six patients with moderate to severe mucosal damage and was found to be low.« less

Evaluation of BBL™ Sensi-Discs™ and FTA® cards as sampling devices for detection of rotavirus in stool samples

PubMed Central

Tam, Ka Ian; Esona, Mathew D.; Williams, Alice; Ndze, Valentine N.; Boula, Angeline; Bowen, Michael D.

2015-01-01

Rotavirus is the most important cause of severe childhood gastroenteritis worldwide. Rotavirus vaccines are available and rotavirus surveillance is carried out to assess vaccination impact. In surveillance studies, stool samples are stored typically at 4°C or frozen to maintain sample quality. Uninterrupted cold storage is a problem in developing countries because of power interruptions. Cold-chain transportation of samples from collection sites to testing laboratories is costly. In this study, we evaluated the use of BBL™ Sensi-Discs™ and FTA® cards for storage and transportation of samples for virus isolation, EIA, and RT-PCR testing. Infectious rotavirus was recovered after 30 days of storage on Sensi-Discs™ at room temperature. We were able to genotype 98–99% of samples stored on Sensi-Discs™ and FTA® cards at temperatures ranging from −80°C to 37°C up to 180 days. A field sampling test using samples prepared and shipped from Cameroon, showed that both matrices yielded 100% genotyping success compared with whole stool and Sensi-Discs™ demonstrated 95% concordance with whole stool in EIA testing. The utilization of BBL™ Sensi-Discs™ and FTA® cards for stool sample storage and shipment has the potential to have great impact on global public health by facilitating surveillance and epidemiological investigations of rotavirus strains worldwide at a reduced cost. PMID:26022083

Evaluation of BBL™ Sensi-Discs™ and FTA® cards as sampling devices for detection of rotavirus in stool samples.

PubMed

Tam, Ka Ian; Esona, Mathew D; Williams, Alice; Ndze, Valantine N; Boula, Angeline; Bowen, Michael D

2015-09-15

Rotavirus is the most important cause of severe childhood gastroenteritis worldwide. Rotavirus vaccines are available and rotavirus surveillance is carried out to assess vaccination impact. In surveillance studies, stool samples are stored typically at 4°C or frozen to maintain sample quality. Uninterrupted cold storage is a problem in developing countries because of power interruptions. Cold-chain transportation of samples from collection sites to testing laboratories is costly. In this study, we evaluated the use of BBL™ Sensi-Discs™ and FTA(®) cards for storage and transportation of samples for virus isolation, EIA, and RT-PCR testing. Infectious rotavirus was recovered after 30 days of storage on Sensi-Discs™ at room temperature. We were able to genotype 98-99% of samples stored on Sensi-Discs™ and FTA(®) cards at temperatures ranging from -80°C to 37°C up to 180 days. A field sampling test using samples prepared and shipped from Cameroon, showed that both matrices yielded 100% genotyping success compared with whole stool and Sensi-Discs™ demonstrated 95% concordance with whole stool in EIA testing. The utilization of BBL™ Sensi-Discs™ and FTA(®) cards for stool sample storage and shipment has the potential to have great impact on global public health by facilitating surveillance and epidemiological investigations of rotavirus strains worldwide at a reduced cost. Published by Elsevier B.V.

Diagnostic value of secreted frizzled-related protein 2 gene promoter hypermethylation in stool for colorectal cancer: A meta-analysis.

PubMed

Zhou, Zhiran; Zhang, Huitian; Lei, Yunxia

2016-10-01

To evaluate the diagnostic value of secreted frizzled-related protein 2 (SFRP2) gene promoter hypermethylation in stool for colorectal cancer (CRC). Open published diagnostic study of SFRP2 gene promoter hypermethylation in stool for CRC detection was electronic searched in the databases of PubMed, EMBASE, Cochrane Library, Web of Science, and China National Knowledge Infrastructure. The data of true positive, false positive false negative, and true negative identified by stool SFRP2 gene hypermethylation was extracted and pooled for diagnostic sensitivity, specificity, and summary receiver operating characteristic (SROC) curve. According to the inclusion and exclusion criteria, we finally included nine publications with 792 cases in the meta-analysis. Thus, the diagnostic sensitivity was aggregated through random effect model. The pooled sensitivity was 0.82 with the corresponding 95% confidence interval (95% CI) of 0.79-0.85; the pooled specificity and its corresponding 95% CI were 0.47 and 0.40-0.53 by the random effect model; we pooled the SROC curve by sensitivity versus specificity according to data published in the nine studies. The area under the SROC curve was 0.70 (95% CI: 0.65-0.73). SFRP2 gene promoter hypermethylation in stool can was a potential biomarker for CRC diagnosis with relative high sensitivity.

Comparison of Individual and Pooled Stool Samples for the Assessment of Soil-Transmitted Helminth Infection Intensity and Drug Efficacy

PubMed Central

Mekonnen, Zeleke; Meka, Selima; Ayana, Mio; Bogers, Johannes; Vercruysse, Jozef; Levecke, Bruno

2013-01-01

Background In veterinary parasitology samples are often pooled for a rapid assessment of infection intensity and drug efficacy. Currently, studies evaluating this strategy in large-scale drug administration programs to control human soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura, and hookworm), are absent. Therefore, we developed and evaluated a pooling strategy to assess intensity of STH infections and drug efficacy. Methods/Principal Findings Stool samples from 840 children attending 14 primary schools in Jimma, Ethiopia were pooled (pool sizes of 10, 20, and 60) to evaluate the infection intensity of STHs. In addition, the efficacy of a single dose of mebendazole (500 mg) in terms of fecal egg count reduction (FECR; synonym of egg reduction rate) was evaluated in 600 children from two of these schools. Individual and pooled samples were examined with the McMaster egg counting method. For each of the three STHs, we found a significant positive correlation between mean fecal egg counts (FECs) of individual stool samples and FEC of pooled stool samples, ranging from 0.62 to 0.98. Only for A. lumbricoides was any significant difference in mean FEC of the individual and pooled samples found. For this STH species, pools of 60 samples resulted in significantly higher FECs. FECR for the different number of samples pooled was comparable in all pool sizes, except for hookworm. For this parasite, pools of 10 and 60 samples provided significantly higher FECR results. Conclusion/Significance This study highlights that pooling stool samples holds promise as a strategy for rapidly assessing infection intensity and efficacy of administered drugs in programs to control human STHs. However, further research is required to determine when and how pooling of stool samples can be cost-effectively applied along a control program, and to verify whether this approach is also applicable to other NTDs. PMID:23696905

Organometallic macromolecules with piano stool coordination repeating units: chain configuration and stimulated solution behaviour.

PubMed

Cao, Kai; Ward, Jonathan; Amos, Ryan C; Jeong, Moon Gon; Kim, Kyoung Taek; Gauthier, Mario; Foucher, Daniel; Wang, Xiaosong

2014-09-11

Theoretical calculations illustrate that organometallic macromolecules with piano stool coordination repeating units (Fe-acyl complex) adopt linear chain configuration with a P-Fe-C backbone surrounded by aromatic groups. The macromolecules show molecular weight-dependent and temperature stimulated solution behaviour in DMSO.

Evaluation of a New Selective Medium, BD BBL CHROMagar MRSA II, for Detection of Methicillin-Resistant Staphylococcus aureus in Stool Specimens ▿

PubMed Central

Havill, Nancy L.; Boyce, John M.

2010-01-01

We compared the recovery of methicillin-resistant Staphylococcus aureus (MRSA) on a new selective chromogenic agar, BD BBL CHROMagar MRSA II (CMRSAII), to that on traditional culture media with 293 stool specimens. The recovery of MRSA was greater on the CMRSAII agar. Screening of stool samples can identify patients who were previously unknown carriers of MRSA. PMID:20392908

Analysis of 13C-mixed triacylglycerol in stool by bulk (EA-IRMS) and compound specific (GC/MS) methods.

PubMed

Slater, C; Ling, S C; Preston, T; Weaver, L T

2002-06-01

This paper was presented in poster form at the 17th International Congress of Nutrition, August 27-31, Vienna, Austria (Annals of Nutrition & Metabolism 2001; 45(Suppl.1):349). Some of the data were also presented in poster form at the British Society of Gastroenterology Meeting, March 18-21, Glasgow, UK (Gut 2001; 48(Suppl.1):A91). The 13C-mixed triacylglycerol (MTG) breath test is used to measure intraluminal fat digestion. In normal digestion, 20-40% of the ingested 13C label is recovered in breath CO2. We aimed to identify the proportions of ingested label excreted in stool, as well as breath following ingestion of 13C-MTG by children with impaired exocrine pancreatic function and healthy controls. 13C enrichment of breath samples was measured by continuous flow isotope ratio mass spectrometry (IRMS) and cumulative percent dose recovered (cPDR) in 10 h was calculated. Total 13C of a faecal fat extract from each stool was measured by elemental analyser-IRMS, and 13C enrichment and concentration of the TBDMS derivative of octanoic acid was measured by GC/MS after hydrolysis of the fat extract. Stool 5-day cPDR was calculated. Mean breath cPDR was 35%. Mean cPDR in stool by combustion-IRMS and GC/ MS, respectively, was 0.8% and 1.0%. Therefore, the remaining 64% of the 13C label must remain in the body and variability in breath cPDR is due to postabsorptive rather than predigestive factors.

Collection media and delayed freezing effects on microbial composition of human stool.

PubMed

Flores, Roberto; Shi, Jianxin; Yu, Guoqin; Ma, Bing; Ravel, Jacques; Goedert, James J; Sinha, Rashmi

2015-01-01

Different bacteria in stool have markedly varied growth and survival when stored at ambient temperature. It is paramount to develop optimal biostabilization of stool samples during collection and assess long-term storage for clinical specimens and epidemiological microbiome studies. We evaluated the effect of collection media and delayed freezing up to 7 days on microbial composition. Ten participants collected triplicate stool samples each into no media as well as RNAlater® with and without kanamycin or ciprofloxacin. For each set of conditions, triplicate samples were frozen on dry ice immediately (time = 0) or frozen at -80 °C after 3-days and 7-days incubation at 25 °C. Microbiota metrics were estimated from Illumina MiSeq sequences of 16S rRNA gene fragments (V3-V4 region). Intraclass correlation coefficients (ICC) across triplicates, collection media, and incubation time were estimated for taxonomy and alpha and beta diversity metrics. RNAlater® alone yielded the highest ICCs for diversity metrics at time = 0 [ICC median 0.935 (range 0.89-0.97)], but ICCs varied greatly (range 0.44-1.0) for taxa with relative abundances <1%. The 3- and 7-day freezing delays were generally associated with stable beta diversity for all three media conditions. Freezing delay caused increased variance for Shannon index (median ICC 0.77) and especially for observed species abundance (median ICC 0.47). Variance in observed species abundance and in phylogenetic distance whole tree was similarly increased with a 7-day delay. Antibiotics did not mitigate variance. No media had inferior ICCs at time 0 and differed markedly from any media in microbiome composition (e.g., P =0.01 for relative abundance of Bacteroidetes). Bacterial community composition was stable for 7 days at room temperature in RNAlater® alone. RNAlater® provides some stability for beta diversity analyses, but analyses of rare taxa will be inaccurate if specimens are not frozen immediately. RNAlater® could be

[Fungi isolated from the stool in patients with gastrointestinal disorders in 2005 - 2009].

PubMed

Macura, Anna B; Witalis, Jadwiga

2010-01-01

The mycological examination of 2242 stool specimens sampled form patients with non-specific gastrointestinal tract ailments was focused on the spectrum of fungal species isolated in culture, the frequency of isolation of the particular species high enough to indicate microbiological imbalance in the gut flora as well as evaluation of the fungal susceptibility to the antifungal agents. Fungal presence was detected in 61.5% of the specimens tested. The fungal flora isolated was as follows: C. albicans 70.9% of the isolates, Candida non-albicans 20.8% (including C krusei 3.40%, C. parapsilosis 1.88%, C. glabrata 1.59%), other genera 8.34% (including S. cerevisiae 5.58%, Geotrichum sp. 1.16%, and Trichosporon sp. 1.01%). The results of semiquantitative evaluation of the intensity of growth of the fungi isolated from the stool revealed that imbalance in the gut flora occured in 20.8% of the cases. Candida strains tested using Fungitest were less susceptible to azoles than to amphotericin B and 5-fluorocytosine. Decreased susceptibiliy or resistance to antimycotics was relatively often found among Candida non-albicans strains.

Evaluation of Toxoplasma ELITe MGB Real-Time PCR Assay for Diagnosis of Toxoplasmosis

PubMed Central

Brenier-Pinchart, Marie-Pierre; Yera, Hélène; Belaz, Sorya; Varlet-Marie, Emmanuelle; Bastien, Patrick

2017-01-01

ABSTRACT Molecular diagnosis of congenital toxoplasmosis or disseminated toxoplasmosis is based mainly on PCR. The repeated DNA element rep529 has become the main DNA target used in most PCR methods, whether laboratory developed or commercial. In this multicenter study, we evaluated the Toxoplasma ELITe MGB (Elitech) commercial kit by comparison with three reference quantitative PCR assays (RAs) used routinely in three proficient laboratories of the French National Reference Center for Toxoplasmosis network, using Toxoplasma calibrated suspensions diluted to obtain a range of concentrations from 0.1 to 10,000 parasites/ml. These suspensions were extracted with either the DNA extraction kit (EXTRAblood; Elitech) recommended by the manufacturer or the QIAamp DNA minikit (Qiagen). The Toxoplasma ELITe MGB assay was also evaluated on a panel of 128 clinical samples, including 56 amniotic fluid samples, 55 placenta samples, and various other samples, of which 95 originated from patients with proven toxoplasmosis. The ELITe MGB assay amplified low-concentration replicates (<10 parasites/ml) of calibrated suspensions less frequently than the RAs of 2/3 laboratories. Additionally, the combination of EXTRAblood and Toxoplasma ELITe MGB yielded poorer sensitivity than the combination of QIAamp DNA minikit and ELITe MGB for low parasite concentrations (P < 0.001 for 1 parasite/ml). On clinical samples, the sensitivity and the specificity of the commercial assay were 89% and 100%, respectively. The sensitivity ranged from 79% (placenta samples) to 100% (amniotic fluid samples). Overall, this study shows that the Toxoplasma ELITe MGB assay is suitable for the diagnosis of toxoplasmosis from non-cell-rich or non-hemoglobin-rich samples and that the EXTRAblood kit is not optimal. PMID:28202794

Evaluation of Toxoplasma ELITe MGB Real-Time PCR Assay for Diagnosis of Toxoplasmosis.

PubMed

Robert-Gangneux, Florence; Brenier-Pinchart, Marie-Pierre; Yera, Hélène; Belaz, Sorya; Varlet-Marie, Emmanuelle; Bastien, Patrick

2017-05-01

Molecular diagnosis of congenital toxoplasmosis or disseminated toxoplasmosis is based mainly on PCR. The repeated DNA element rep529 has become the main DNA target used in most PCR methods, whether laboratory developed or commercial. In this multicenter study, we evaluated the Toxoplasma ELITe MGB (Elitech) commercial kit by comparison with three reference quantitative PCR assays (RAs) used routinely in three proficient laboratories of the French National Reference Center for Toxoplasmosis network, using Toxoplasma calibrated suspensions diluted to obtain a range of concentrations from 0.1 to 10,000 parasites/ml. These suspensions were extracted with either the DNA extraction kit (EXTRAblood; Elitech) recommended by the manufacturer or the QIAamp DNA minikit (Qiagen). The Toxoplasma ELITe MGB assay was also evaluated on a panel of 128 clinical samples, including 56 amniotic fluid samples, 55 placenta samples, and various other samples, of which 95 originated from patients with proven toxoplasmosis. The ELITe MGB assay amplified low-concentration replicates (<10 parasites/ml) of calibrated suspensions less frequently than the RAs of 2/3 laboratories. Additionally, the combination of EXTRAblood and Toxoplasma ELITe MGB yielded poorer sensitivity than the combination of QIAamp DNA minikit and ELITe MGB for low parasite concentrations ( P < 0.001 for 1 parasite/ml). On clinical samples, the sensitivity and the specificity of the commercial assay were 89% and 100%, respectively. The sensitivity ranged from 79% (placenta samples) to 100% (amniotic fluid samples). Overall, this study shows that the Toxoplasma ELITe MGB assay is suitable for the diagnosis of toxoplasmosis from non-cell-rich or non-hemoglobin-rich samples and that the EXTRAblood kit is not optimal. Copyright © 2017 American Society for Microbiology.

Real-time PCR using SYBR Green for the detection of Shigella spp. in food and stool samples.

PubMed

Mokhtari, W; Nsaibia, S; Gharbi, A; Aouni, M

2013-02-01

Shigella spp are exquisitely fastidious Gram negative organisms that frequently get missed in the detection by traditional culture methods. For this reason, this work has adapted a classical PCR for detection of Shigella in food and stool specimens to real-time PCR using the SYBR Green format. This method follows a melting curve analysis to be more rapid and provide both qualitative and quantitative data about the targeted pathogen. A total of 117 stool samples with diarrhea and 102 food samples were analyzed in Public Health Regional Laboratory of Nabeul by traditional culture methods and real-time PCR. To validate the real-time PCR assay, an experiment was conducted with both spiked and naturally contaminated stool samples. All Shigella strains tested were ipaH positive and all non-Shigella strains yielded no amplification products. The melting temperature (T(m) = 81.5 ± 0.5 °C) was consistently specific for the amplicon. Correlation coefficients of standard curves constructed using the quantification cycle (C(q)) versus copy numbers of Shigella showed good linearity (R² = 0.995; slope = 2.952) and the minimum level of detection was 1.5 × 10³ CFU/g feces. All food samples analyzed were negative for Shigella by standard culture methods, whereas ipaH was detected in 8.8% culture negative food products. Moreover, the ipaH specific PCR system increased the detection rate over that by culture alone from 1.7% to 11.1% among patients with diarrhea. The data presented here shows that the SYBR Green I was suitable for use in the real-time PCR assay, which provided a specific, sensitive and efficient method for the detection and quantification of Shigella spp in food and stool samples. Copyright © 2012 Elsevier Ltd. All rights reserved.

Evaluation of a rapid method to exclude the presence of certain enteric pathogens in stool specimens.

PubMed Central

Teti, G; Burdash, N M; Zamboni, C; Fava, C; Tomasello, F; Mastroeni, P

1984-01-01

A new commercial method intended to exclude the presence of Salmonella spp., Shigella spp., and Yersinia enterocolitica and to presumptively identify Salmonella isolates within 2 h after primary isolation from stool specimens was evaluated. This system is marketed in Europe as API Z and in the United States as Rapid SST. The strip consists of five pairs of cupules for the screening of five lactose-negative colonies. The first cupule of each pair detects the presence of five enzymatic activities, whereas the second serves to maintain the strain for additional testing if necessary. A total of 197 fresh isolates from stool specimens and 217 stock cultures of Salmonella spp., Shigella spp., and Yersinia enterocolitica were tested, with the API 20E system as a reference method. In the stool specimens, 77.3% of the bacteria could be excluded from further workup for the presence of these organisms within 2 h. Over 97% of the stock strains and each of three fresh Salmonella isolates tested produced a reaction pattern corresponding to a correct presumptive identification. This reaction pattern was not produced by any isolate other than the Salmonella isolates. The API Z system can be used as a screen for the presence of Salmonella and Shigella spp. and can provide an accurate presumptive identification of Salmonella isolates within 2 h after primary isolation. PMID:6394610

Mathematical inference on helminth egg counts in stool and its applications in mass drug administration programmes to control soil-transmitted helminthiasis in public health.

PubMed

Levecke, Bruno; Anderson, Roy M; Berkvens, Dirk; Charlier, Johannes; Devleesschauwer, Brecht; Speybroeck, Niko; Vercruysse, Jozef; Van Aelst, Stefan

2015-03-01

In the present study, we present a hierarchical model based on faecal egg counts (FECs; expressed in eggs per 1g of stool) in which we first describe the variation in FECs between individuals in a particular population, followed by describing the variance due to counting eggs under a microscope separately for each stool sample. From this general framework, we discuss how to calculate a sample size for assessing a population mean FEC and the impact of an intervention, measured as reduction in FECs, for any scenario of soil-transmitted helminth (STH) epidemiology (the intensity and aggregation of FECs within a population) and diagnostic strategy (amount of stool examined (∼sensitivity of the diagnostic technique) and examination of individual/pooled stool samples) and on how to estimate prevalence of STH in the absence of a gold standard. To give these applications the most wide relevance as possible, we illustrate each of them with hypothetical examples. Copyright © 2015 Elsevier Ltd. All rights reserved.

How Long Can Stool Samples Be Fixed for an Accurate Diagnosis of Soil-Transmitted Helminth Infection Using Mini-FLOTAC?

PubMed Central

Barda, Beatrice; Albonico, Marco; Ianniello, Davide; Ame, Shaali M.; Keiser, Jennifer; Speich, Benjamin; Rinaldi, Laura; Cringoli, Giuseppe; Burioni, Roberto; Montresor, Antonio; Utzinger, Jürg

2015-01-01

Background Kato-Katz is a widely used method for the diagnosis of soil-transmitted helminth infection. Fecal samples cannot be preserved, and hence, should be processed on the day of collection and examined under a microscope within 60 min of slide preparation. Mini-FLOTAC is a technique that allows examining fixed fecal samples. We assessed the performance of Mini-FLOTAC using formalin-fixed stool samples compared to Kato-Katz and determined the dynamics of prevalence and intensity estimates of soil-transmitted helminth infection over a 31-day time period. Methodology The study was carried out in late 2013 on Pemba Island, Tanzania. Forty-one children were enrolled and stool samples were subjected on the day of collection to a single Kato-Katz thick smear and Mini-FLOTAC examination; 12 aliquots of stool were fixed in 5% formalin and subsequently examined by Mini-FLOTAC up to 31 days after collection. Principal Findings The combined results from Kato-Katz and Mini-FLOTAC revealed that 100% of children were positive for Trichuris trichiura, 85% for Ascaris lumbricoides, and 54% for hookworm. Kato-Katz and Mini-FLOTAC techniques found similar prevalence estimates for A. lumbricoides (85% versus 76%), T. trichiura (98% versus 100%), and hookworm (42% versus 51%). The mean eggs per gram of stool (EPG) according to Kato-Katz and Mini-FLOTAC was 12,075 and 11,679 for A. lumbricoides, 1,074 and 1,592 for T. trichiura, and 255 and 220 for hookworm, respectively. The mean EPG from day 1 to 31 of fixation was stable for A. lumbricoides and T. trichiura, but gradually declined for hookworm, starting at day 15. Conclusions/Significance The findings of our study suggest that for a qualitative diagnosis of soil-transmitted helminth infection, stool samples can be fixed in 5% formalin for at least 30 days. However, for an accurate quantitative diagnosis of hookworm, we suggest a limit of 15 days of preservation. Our results have direct implication for integrating soil

Implementation of a Clinical Decision Support Tool for Stool Cultures and Parasitological Studies in Hospitalized Patients

PubMed Central

Nikolic, D.; Richter, S. S.; Asamoto, K.; Wyllie, R.; Tuttle, R.

2017-01-01

ABSTRACT There is substantial evidence that stool culture and parasitological examinations are of minimal to no value after 3 days of hospitalization. We implemented and studied the impact of a clinical decision support tool (CDST) to decrease the number of unnecessary stool cultures (STCUL), ova/parasite (O&P) examinations, and Giardia/Cryptosporidium enzyme immunoassay screens (GC-EIA) performed for patients hospitalized >3 days. We studied the frequency of stool studies ordered before or on day 3 and after day 3 of hospitalization (i.e., categorical orders/total number of orders) before and after this intervention and denoted the numbers and types of microorganisms detected within those time frames. This intervention, which corresponded to a custom-programmed hard-stop alert tool in the Epic hospital information system, allowed providers to override the intervention by calling the laboratory, if testing was deemed medically necessary. Comparative statistics were employed to determine significance, and cost savings were estimated based on our internal costs. Before the intervention, 129/670 (19.25%) O&P examinations, 47/204 (23.04%) GC-EIA, and 249/1,229 (20.26%) STCUL were ordered after 3 days of hospitalization. After the intervention, 46/521 (8.83%) O&P examinations, 27/157 (17.20%) GC-EIA, and 106/1,028 (10.31%) STCUL were ordered after 3 days of hospitalization. The proportions of reductions in the number of tests performed after 3 days and the associated P values were 54.1% for O&P examinations (P < 0.0001), 22.58% for GC-EIA (P = 0.2807), and 49.1% for STCUL (P < 0.0001). This was estimated to have resulted in $8,108.84 of cost savings. The electronic CDST resulted in a substantial reduction in the number of evaluations of stool cultures and the number of parasitological examinations for patients hospitalized for more than 3 days and in a cost savings while retaining the ability of the clinician to obtain these tests if clinically indicated. PMID:28954902

Implementation of a Clinical Decision Support Tool for Stool Cultures and Parasitological Studies in Hospitalized Patients.

PubMed

Nikolic, D; Richter, S S; Asamoto, K; Wyllie, R; Tuttle, R; Procop, G W

2017-12-01

There is substantial evidence that stool culture and parasitological examinations are of minimal to no value after 3 days of hospitalization. We implemented and studied the impact of a clinical decision support tool (CDST) to decrease the number of unnecessary stool cultures (STCUL), ova/parasite (O&P) examinations, and Giardia / Cryptosporidium enzyme immunoassay screens (GC-EIA) performed for patients hospitalized >3 days. We studied the frequency of stool studies ordered before or on day 3 and after day 3 of hospitalization (i.e., categorical orders/total number of orders) before and after this intervention and denoted the numbers and types of microorganisms detected within those time frames. This intervention, which corresponded to a custom-programmed hard-stop alert tool in the Epic hospital information system, allowed providers to override the intervention by calling the laboratory, if testing was deemed medically necessary. Comparative statistics were employed to determine significance, and cost savings were estimated based on our internal costs. Before the intervention, 129/670 (19.25%) O&P examinations, 47/204 (23.04%) GC-EIA, and 249/1,229 (20.26%) STCUL were ordered after 3 days of hospitalization. After the intervention, 46/521 (8.83%) O&P examinations, 27/157 (17.20%) GC-EIA, and 106/1,028 (10.31%) STCUL were ordered after 3 days of hospitalization. The proportions of reductions in the number of tests performed after 3 days and the associated P values were 54.1% for O&P examinations ( P < 0.0001), 22.58% for GC-EIA ( P = 0.2807), and 49.1% for STCUL ( P < 0.0001). This was estimated to have resulted in $8,108.84 of cost savings. The electronic CDST resulted in a substantial reduction in the number of evaluations of stool cultures and the number of parasitological examinations for patients hospitalized for more than 3 days and in a cost savings while retaining the ability of the clinician to obtain these tests if clinically indicated. Copyright © 2017

High within-day variability of fecal calprotectin levels in patients with active ulcerative colitis: what is the best timing for stool sampling?

PubMed

Calafat, Margalida; Cabré, Eduard; Mañosa, Míriam; Lobatón, Triana; Marín, Laura; Domènech, Eugeni

2015-05-01

Fecal calprotectin (FC) is considered the best noninvasive way to assess disease activity in ulcerative colitis (UC). However, it is not known which is the more suitable moment for stool sampling in patients with increased stool frequency. The aims of this study were to assess the intraindividual variation of FC within day and to evaluate if the first bowel movement in the morning is the more suitable sample for FC measurement in patients with acute flares of UC. Patients admitted because of active UC were invited to collect samples from several bowel movements (including the first in the morning) during the same day providing their ordinal chronology. FC was measured by means of a quantitative rapid point-of-care test based on lateral flow assay immunochromatography. Eighteen patients were included for a total of 56 stool samples. Most patients had extensive UC and severe disease activity. Within-day FC values varied widely, and the median coefficient of variation was 40% (5%-114%) with a median range of variation of FC values of 3887 mg/kg (69-9946). The sample from the first stool in the morning obtained the highest individual FC within-day value in 33.3% of cases and the lowest in 38.9%. FC values widely vary between motions in patients with active UC. Stool sample collection from the first bowel movement in the morning does not ensure the highest or lowest within-day FC value. In patients with overt active UC, a single FC determination should not be used as the basis for therapeutic strategies.

One-Step Purification of Enterocytozoon bieneusi Spores from Human Stools by Immunoaffinity Expanded-Bed Adsorption

PubMed Central

Accoceberry, Isabelle; Thellier, Marc; Datry, Annick; Desportes-Livage, Isabelle; Biligui, Sylvestre; Danis, Martin; Santarelli, Xavier

2001-01-01

An original, reliable, and reproducible method for the purification of Enterocytozoon bieneusi spores from human stools is described. We recently reported the production of a species-specific monoclonal antibody (MAb) 6E52D9 immunoglobulin G2a (IgG2a) raised against the exospore of E. bieneusi spore walls. The MAb was used as a ligand to develop an immunoaffinity matrix. The mouse IgG2a MAb was bound directly to a Streamline rProtein A adsorbent, used for expanded-bed adsorption of immunoglobulins, for optimal spatial orientation of the antibody and maximum binding efficiency of the antigen. The complex was then cross-linked covalently using dimethyl pimelimidate dihydrochloride. After incubation of the immunoaffinity matrix with filtered stool samples containing numerous E. bieneusi spores and before elution with 6 M guanidine HCl, the expansion of the adsorbent bed eliminated all the fecal contaminants. The presence of spores in the elution fractions was determined by an indirect immunofluorescence antibody test (IFAT). E. bieneusi spores were found in the elution fraction in all four experiments and were still highly antigenic as indicated by IFAT. Smears examined by light microscopy contained very clean spores with no fecal debris or background bacterial and fungal contaminants. However, spore recovery rates were relatively low: an average of 107 spores were purified per run. This technique for isolating E. bieneusi spores directly from human stool samples with a high degree of purity opens up new approaches for studying this parasite. PMID:11326019

One-step purification of Enterocytozoon bieneusi spores from human stools by immunoaffinity expanded-bed adsorption.

PubMed

Accoceberry, I; Thellier, M; Datry, A; Desportes-Livage, I; Biligui, S; Danis, M; Santarelli, X

2001-05-01

An original, reliable, and reproducible method for the purification of Enterocytozoon bieneusi spores from human stools is described. We recently reported the production of a species-specific monoclonal antibody (MAb) 6E52D9 immunoglobulin G2a (IgG2a) raised against the exospore of E. bieneusi spore walls. The MAb was used as a ligand to develop an immunoaffinity matrix. The mouse IgG2a MAb was bound directly to a Streamline rProtein A adsorbent, used for expanded-bed adsorption of immunoglobulins, for optimal spatial orientation of the antibody and maximum binding efficiency of the antigen. The complex was then cross-linked covalently using dimethyl pimelimidate dihydrochloride. After incubation of the immunoaffinity matrix with filtered stool samples containing numerous E. bieneusi spores and before elution with 6 M guanidine HCl, the expansion of the adsorbent bed eliminated all the fecal contaminants. The presence of spores in the elution fractions was determined by an indirect immunofluorescence antibody test (IFAT). E. bieneusi spores were found in the elution fraction in all four experiments and were still highly antigenic as indicated by IFAT. Smears examined by light microscopy contained very clean spores with no fecal debris or background bacterial and fungal contaminants. However, spore recovery rates were relatively low: an average of 10(7) spores were purified per run. This technique for isolating E. bieneusi spores directly from human stool samples with a high degree of purity opens up new approaches for studying this parasite.

Improving compliance to colorectal cancer screening using blood and stool based tests in patients refusing screening colonoscopy in Germany.

PubMed

Adler, Andreas; Geiger, Sebastian; Keil, Anne; Bias, Harald; Schatz, Philipp; deVos, Theo; Dhein, Jens; Zimmermann, Mathias; Tauber, Rudolf; Wiedenmann, Bertram

2014-10-17

Despite strong recommendations for colorectal cancer (CRC) screening, participation rates are low. Understanding factors that affect screening choices is essential to developing future screening strategies. Therefore, this study assessed patient willingness to use non-invasive stool or blood based screening tests after refusing colonoscopy. Participants were recruited during regular consultations. Demographic, health, psychological and socioeconomic factors were recorded. All subjects were advised to undergo screening by colonoscopy. Subjects who refused colonoscopy were offered a choice of non-invasive tests. Subjects who selected stool testing received a collection kit and instructions; subjects who selected plasma testing had a blood draw during the office visit. Stool samples were tested with the Hb/Hp Complex Elisa test, and blood samples were tested with the Epi proColon® 2.0 test. Patients who were positive for either were advised to have a diagnostic colonoscopy. 63 of 172 subjects were compliant to screening colonoscopy (37%). 106 of the 109 subjects who refused colonoscopy accepted an alternative non-invasive method (97%). 90 selected the Septin9 blood test (83%), 16 selected a stool test (15%) and 3 refused any test (3%). Reasons for blood test preference included convenience of an office draw, overall convenience and less time consuming procedure. 97% of subjects refusing colonoscopy accepted a non-invasive screening test of which 83% chose the Septin9 blood test. The observation that participation can be increased by offering non-invasive tests, and that a blood test is the preferred option should be validated in a prospective trial in the screening setting.

Transrenal DNA-based diagnosis of Strongyloides stercoralis (Grassi, 1879) infection: Bayesian latent class modeling of test accuracy.

PubMed

Krolewiecki, Alejandro J; Koukounari, Artemis; Romano, Miryam; Caro, Reynaldo N; Scott, Alan L; Fleitas, Pedro; Cimino, Ruben; Shiff, Clive J

2018-06-01

For epidemiological work with soil transmitted helminths the recommended diagnostic approaches are to examine fecal samples for microscopic evidence of the parasite. In addition to several logistical and processing issues, traditional diagnostic approaches have been shown to lack the sensitivity required to reliably identify patients harboring low-level infections such as those associated with effective mass drug intervention programs. In this context, there is a need to rethink the approaches used for helminth diagnostics. Serological methods are now in use, however these tests are indirect and depend on individual immune responses, exposure patterns and the nature of the antigen. However, it has been demonstrated that cell-free DNA from pathogens and cancers can be readily detected in patient's urine which can be collected in the field, filtered in situ and processed later for analysis. In the work presented here, we employ three diagnostic procedures-stool examination, serology (NIE-ELISA) and PCR-based amplification of parasite transrenal DNA from urine-to determine their relative utility in the diagnosis of S. stercoralis infections from 359 field samples from an endemic area of Argentina. Bayesian Latent Class analysis was used to assess the relative performance of the three diagnostic procedures. The results underscore the low sensitivity of stool examination and support the idea that the use of serology combined with parasite transrenal DNA detection may be a useful strategy for sensitive and specific detection of low-level strongyloidiasis.

Antibiotic resistance among Escherichia coli isolates from stool samples of children aged 3 to 14 years from Ujjain, India

PubMed Central

2013-01-01

Background Antibiotic resistance is a major global public health concern, particularly in settings where few treatment options are available. Limited research has been done on antibiotic resistance in Escherichia coli of Indian children at community level. Therefore we studied antibiotic resistance patterns in E. coli isolates from stool samples of children aged 3-14 years from Ujjain, Central India, to investigate associations of resistance with demographic variables. Methods Children, 3-14 years of age, were included from 30 randomly selected villages of Palwa demographic surveillance site, Ujjain, India. Parents were interviewed using a questionnaire, and stool samples were collected from participating children. E. coli were isolated from stool samples (n = 529), and susceptibility testing to 18 different antibiotics was done using standard methods. Results The proportions of isolates resistant to various antibiotics were, nalidixic acid, (45%), tetracycline (37%), ampicillin (37%), sulfamethoxazole/trimethoprim (29%) and amoxicillin/clavulanic acid (29%). No isolates were resistant to imipenem. Overall, 72% of isolates were resistant to at least one antibiotic and 33% were multi-drug resistant. High rates of cross-resistance were seen for 15 (83%) of the antibiotics studied. E. coli isolates from children with literate mothers were more resistant to penicillins and fluoroquinolones. ESBL-producers comprised 9% of the isolates. Conclusion Antibiotic resistance and cross-resistance were common in E. coli from stools of children. Resistance rates were associated with maternal literacy. PMID:24124728

Application of DNA hybridization techniques in the assessment of diarrheal disease among refugess in Thailand. [Shigella; Escherichia coli; Campylobacter; Cryptosporidium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, D.N.; Echeverria, P.; Pitarangsi, C.

1988-01-01

The epidemiology and etiology of acute diarrheal disease were determined in a Hmong refugee camp on the Thai-Laotian border from April 11 to May 14, 1985. DNA hybridization techniques were used to detect Shigella species, enteroinvasive Escherichia coli, and enterotoxigenic E. coli. A monoclonal enzyme-linked immunosorbent assay was used to detect rotavirus, and standard microbiology was used to detect other enteropathogens. The age-specific diarrheal disease rates were 47 episodes per month per 1000 children less than five years old and 113 episodes per month per 1000 children less than one year old. Rotavirus, enterotoxigenic E. coli, Campylobacter, and Cryptosporidium weremore » the predominant pathogens in children less than two years old. The DNA probe hybridized with 94% of 31 specimens identified as enterotoxigenic E. coli by the standard assays and with none of the specimens in which the standard assays were negative. The probe for Shigella and enteroinvasive E. coli hybridized in eight of 10 stools that contained Shigella and four of 314 stools from which Shigella and enteroinvasive E. coli were not isolated. The use of DNA probes allows specimens to be collected in remote areas with a minimum amount of equipment and technical expertise so that they can be easily transported to a central laboratory for further processing.« less

Microbiome Analysis of Stool Samples from African Americans with Colon Polyps

PubMed Central

Brim, Hassan; Yooseph, Shibu; Zoetendal, Erwin G.; Lee, Edward; Torralbo, Manolito; Laiyemo, Adeyinka O.; Shokrani, Babak; Nelson, Karen; Ashktorab, Hassan

2013-01-01

Background Colonic polyps are common tumors occurring in ~50% of Western populations with ~10% risk of malignant progression. Dietary agents have been considered the primary environmental exposure to promote colorectal cancer (CRC) development. However, the colonic mucosa is permanently in contact with the microbiota and its metabolic products including toxins that also have the potential to trigger oncogenic transformation. Aim To analyze fecal DNA for microbiota composition and functional potential in African Americans with pre-neoplastic lesions. Materials & Methods We analyzed the bacterial composition of stool samples from 6 healthy individuals and 6 patients with colon polyps using 16S ribosomal RNA-based phylogenetic microarray; the Human intestinal Tract Chip (HITChip) and 16S rRNA gene barcoded 454 pyrosequencing. The functional potential was determined by sequence-based metagenomics using 454 pyrosequencing. Results Fecal microbiota profiling of samples from the healthy and polyp patients using both a phylogenetic microarraying (HITChip) and barcoded 454 pyrosequencing generated similar results. A distinction between both sets of samples was only obtained when the analysis was performed at the sub-genus level. Most of the species leading to the dissociation were from the Bacteroides group. The metagenomic analysis did not reveal major differences in bacterial gene prevalence/abundances between the two groups even when the analysis and comparisons were restricted to available Bacteroides genomes. Conclusion This study reveals that at the pre-neoplastic stages, there is a trend showing microbiota changes between healthy and colon polyp patients at the sub-genus level. These differences were not reflected at the genome/functions levels. Bacteria and associated functions within the Bacteroides group need to be further analyzed and dissected to pinpoint potential actors in the early colon oncogenic transformation in a large sample size. PMID:24376500

Relating Stool Microbial Metabolite Levels, Inflammatory Markers and Dietary Behaviors to Screening Colonoscopy Findings in a Racially/Ethnically Diverse Patient Population.

PubMed

Bridges, Kristina M; Diaz, Francisco J; Wang, Zhiwen; Ahmed, Ishfaq; Sullivan, Debra K; Umar, Shahid; Buckles, Daniel C; Greiner, K Allen; Hester, Christina M

2018-02-26

Colorectal cancer (CRC) is the third leading cause of cancer death for both men and women in the United States, yet it is treatable and preventable. African Americans have higher incidence of CRC than other racial/ethnic groups, however, it is unclear whether this disparity is primarily due to environmental or biological factors. Short chain fatty acids (SCFAs) are metabolites produced by bacteria in the colon and are known to be inversely related to CRC progression. The aim of this study is to investigate how stool SCFA levels, markers of inflammation in stool and dietary intake relate to colonoscopy findings in a diverse patient population. Stool samples from forty-eight participants were analyzed for SCFA levels and inflammatory markers (lysozyme, secretory IgA, lactoferrin). Additionally, participants completed the National Cancer Institute's Diet History Questionnaire II (DHQ II) to report dietary intake over the past year. Subsequently, the majority of participants underwent screening colonoscopy. Our results showed that African Americans had higher total levels of SCFAs in stool than other racial/ethnic groups, significantly lower intake of non-starchy vegetables and similar inflammatory marker expression and colonoscopy outcomes, compared to others. This work is an initial exploration into the biological and clinical factors that may ultimately inform personalized screening approaches and clinical decision-making to improve colorectal cancer disparities for African Americans.

Relating Stool Microbial Metabolite Levels, Inflammatory Markers and Dietary Behaviors to Screening Colonoscopy Findings in a Racially/Ethnically Diverse Patient Population

PubMed Central

Bridges, Kristina M.; Diaz, Francisco J.; Wang, Zhiwen; Ahmed, Ishfaq; Sullivan, Debra K.; Umar, Shahid; Buckles, Daniel C.; Greiner, K. Allen; Hester, Christina M.

2018-01-01

Colorectal cancer (CRC) is the third leading cause of cancer death for both men and women in the United States, yet it is treatable and preventable. African Americans have higher incidence of CRC than other racial/ethnic groups, however, it is unclear whether this disparity is primarily due to environmental or biological factors. Short chain fatty acids (SCFAs) are metabolites produced by bacteria in the colon and are known to be inversely related to CRC progression. The aim of this study is to investigate how stool SCFA levels, markers of inflammation in stool and dietary intake relate to colonoscopy findings in a diverse patient population. Stool samples from forty-eight participants were analyzed for SCFA levels and inflammatory markers (lysozyme, secretory IgA, lactoferrin). Additionally, participants completed the National Cancer Institute’s Diet History Questionnaire II (DHQ II) to report dietary intake over the past year. Subsequently, the majority of participants underwent screening colonoscopy. Our results showed that African Americans had higher total levels of SCFAs in stool than other racial/ethnic groups, significantly lower intake of non-starchy vegetables and similar inflammatory marker expression and colonoscopy outcomes, compared to others. This work is an initial exploration into the biological and clinical factors that may ultimately inform personalized screening approaches and clinical decision-making to improve colorectal cancer disparities for African Americans. PMID:29495356

Occurrence of nonspecific reactions among stool specimens tested by the Abbott TestPack rotavirus enzyme immunoassay.

PubMed Central

Lipson, S M; Leonardi, G P; Salo, R J; Schutzbank, T E; Kaplan, M H

1990-01-01

Sixty-five stool specimens obtained from children suffering from gastroenteritis were tested for the presence of antigen to rotavirus by the Abbott TestPack Rotavirus (TestPack) enzyme immunoassay kit. The Kallestad Pathfinder enzyme immunoassay, polyacrylamide gel electrophoresis, immune electron microscopy, and virus isolation were utilized as reference assays. Fifty-four specimens were in accord by TestPack and Kallestad Pathfinder. Among 11 discordant specimens positive with TestPack but negative by Kallestad Pathfinder, rotavirus was not identified by polyacrylamide gel electrophoresis, immune electron microscopy, or isolation in primary African green monkey kidney cell cultures. TestPack displayed a performance specificity of 83%. The inordinately high number of stool specimens reported as false-positive by TestPack precludes the incorporation of this antigen detection kit into our routine regimen of diagnostic virologic testing. Images PMID:2166074

Antimicrobial susceptibility and β-lactamase production in Bacillus cereus isolates from stool of patients, food and environment samples.

PubMed

Savić, Dejana; Miljković-Selimović, Biljana; Lepšanović, Zorica; Tambur, Zoran; Konstantinović, Sonja; Stanković, Nemanja; Ristanović, Elizabeta

2016-10-01

Bacillus cereus (B. cereus) usually ingested by food can cause two types of diseases: vomiting due to the presence of emetic toxin and diarrheal syndrome, due to the presence of diarrheal toxins. Systemic manifestations can also occur. The severe forms of disease demand antibiotic treatmant. The aim of this study was to determine the differences in antibiotic susceptibility and β-lactamase activity of B. cereus isolates from stools of humans, food and environment. Identification of B. cereus was performed with selective medium, classical biochemical test and polymerase chain reaction (PCR) with primers specific for bal gene. Thirty isolates from each group were analysed for antibiotic susceptibility using the disk-diffusion assay. Production of β-lactamase was determined by cefinase test, and double-disc method. All strains identified as B. cereus using classical biochemical test, yielded 533 bp fragment with PCR. Isolates from all the three groups were susceptible to imipenem, vancomycin, and erythromycin. All isolates were susceptible to ciprofloxacin but one from the environment. A statistically significant difference between the groups was confirmed to tetracycline and trimethoprim-sulphamethoxazole sensitivity. A total of 28/30 (93.33%) samples from the foods and 25/30 (83.33%) samples from environment were approved sensitive to tetracycline, while 10/30 (33.33%) isolates from stools were sensitive. Opposite to this result, high susceptibility to trimethoprim-sulphamethoxazole was shown in samples from stools (100%), while isolates from foods (63.33%) and from environment (70%) had low susceptibility. All samples produced β-lactamases. The strains of B. cereus from all the three groups showed high rate of sensitivity to most tested antibiotics, except to tetracycline in samples from human stool and to trimethoprim-sulphamethoxazole in samples from food and environment. The production of β-lactamases was confirmed in all the strains.

Novel and classical human astroviruses in stool and cerebrospinal fluid: comprehensive screening in a tertiary care hospital, Switzerland.

PubMed

Cordey, Samuel; Vu, Diem-Lan; Zanella, Marie-Celine; Turin, Lara; Mamin, Aline; Kaiser, Laurent

2017-09-20

Classical human astroviruses (HAstV) are the third most common cause of non-bacterial acute gastroenteritis. Due to the lack of routine molecular assays, novel HAstV are underdiagnosed and the magnitude of their contribution to clinical disease remains unknown. To better understand their prevalence and the susceptible patient profile, we conducted a comprehensive screening of novel and classical HAstV in stool and cerebrospinal fluid (CSF) samples collected for clinical care in a tertiary care hospital using a specially designed rRT-PCR panel for the detection of novel (MLB1-3 and VA1-4) and classical HAstV. Of the 654 stool samples, 20 were positive for HAstV, and the novel (n=10; 3 MLB1, 4 MLB2; 3 VA2) and classical (n=10) serotypes were equally prevalent. None of the 105 CSF samples were positive. Investigating the patient profile, we found a higher prevalence (P=0.0002) of both novel and classical HAstV in pediatric stool samples (3.4% and 3%, respectively) compared with adult stool samples (0.5% and 0.7%, respectively). Furthermore, all novel and classical HAstV-positive pediatric subjects were ≤four years old, demonstrating similar susceptible populations. Forty-five percent of positive patients were immunocompromised (novel: 40%, classical: 50%). A comparison of novel and classical HAstV-positive cases showed a lower viral load for novel HAstV (P=0.0007) with significantly more upper respiratory symptoms (70% of subjects; P=0.02); this observation may suggest a unique pathogenic pathway. This study confirms the clinical and epidemiological relevance of novel HAstV and identifies a target population in which routine screening may yield clinically valuable information.

From an Easily Accessible Pentacarbonylcobalt(I) Salt to Piano-Stool Cations [(arene)Co(CO)2 ].

PubMed

Meier, Stefan C; Holz, Albina; Schmidt, Alexei; Kratzert, Daniel; Himmel, Daniel; Krossing, Ingo

2017-10-17

The facile synthesis of a pentacarbonyl cobalt(I) salt without the need for a superacid as solvent is presented. This salt, [Co(CO) 5 ] + [Al(OR F ) 4 ] - {R F =C(CF 3 ) 3 }, readily accessible on a multigram scale, undergoes substitution reactions with arenes yielding the hitherto unknown class of two-legged cobalt piano-stool complexes [(arene)Co(CO) 2 ] + with four different arene ligands. Such a substitution chemistry would have been impossible in superacid solution, as the arenes used would have been oxidized and/or protonated. Thus, the general approach described herein may have a wide synthetic use. Additionally, the thermochemistry of the piano-stool complexes is shown to be not easy to describe computationally and most of the established DFT methods overestimate the reaction energies. Only CCSD(T) calculations close to the basis set limit gave energies fully agreeing with the experiment. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comparison of stool collection on site versus at home in a population-based study : feasibility and participants' preference in Pretest 2 of the German National Cohort.

PubMed

Schultze, A; Akmatov, M K; Andrzejak, M; Karras, N; Kemmling, Y; Maulhardt, A; Wieghold, S; Ahrens, W; Günther, K; Schlenz, H; Krause, G; Pessler, F

2014-11-01

For certain laboratory investigations it is necessary to obtain native stool samples and process them within a narrow time window at the point of contact or a nearby laboratory. However, it is not known whether it is feasible to obtain stool samples from asymptomatic individuals during an appointment in a study center (SC). We therefore compared participants' preference, feasibility and acceptance of stool sample collection during the appointment at the study center (on-site sampling) to collection at home after the appointment. The study was conducted at two sites in Northern Germany (Bremen, n = 156; Hannover, n = 147) during the Pretest 2 phase of the German National Cohort (GNC), drawing upon a randomly selected population supplemented by a small convenience sample. In the study center, the participants were given the choice to provide a stool sample during the appointment or to collect a sample later at home and return it by mail. In all, 303 of the 351 participants (86 %) of Pretest 2 at these sites participated in this feasibility study. Only 7.9 % (24/303) of the participants chose on-site collection, whereas 92 % (279/303) chose at-home collection. There were significant differences between the two study sites in that 14 % (21/147) of participants in Hannover and 2 % (3/156) of participants in Bremen chose on-site collection. Compliance was high in both groups, as 100 % (24/24) and 98 % (272/279) of participants in the on-site and at-home groups, respectively, provided complete samples. Both methods were highly accepted, as 92 % of the participants in each group (22/24 and 227/248) stated that stool collection at the respective site was acceptable. When given a choice, most participants in this population-based study preferred home collection of stool samples to collection in the study center. Thus, native stool samples for immediate processing in the study center may potentially be obtained only from a subpopulation of

Difference in Ulex europaeus agglutinin I-binding activity of decay-accelerating factor detected in the stools of patients with colorectal cancer and ulcerative colitis.

PubMed

Okazaki, Hiroaki; Mizuno, Motowo; Nasu, Junichirou; Makidono, Chiho; Hiraoka, Sakiko; Yamamoto, Kazuhide; Okada, Hiroyuki; Fujita, Teizo; Tsuji, Takao; Shiratori, Yasushi

2004-03-01

Expression of decay-accelerating factor (DAF, CD55), a complement-regulatory glycoprotein, is enhanced in colorectal-cancer (CC) cells and colonic epithelium in ulcerative colitis (UC), and stools from these patients contain increased amounts of DAF. Carbohydrate chains of glycoproteins are often altered during malignant transformation or inflammation. In this study, we investigated whether DAF molecules in patients with CC and those with UC differ with respect to oligosaccharide side chains. We analyzed DAF in stools and homogenates of colonic-tissue specimens obtained from patients with CC or UC using solid-phase enzyme-linked assay and Western blotting for reactivity with the lectins Ulex europaeus agglutinin I (UEA-I), wheat-germ agglutinin, peanut agglutinin, and concanavalin A. UEA-I bound to DAF in stools from patients with UC but not in that from the stools of CC patients, as demonstrated on the solid-phase enzyme-linked assay (P <.05, Mann-Whitney U test) and Western blotting. Binding of UEA-I was specifically inhibited by the addition of fucose. The difference in UEA-I reactivity with DAF was observed also in colonic-tissue homogenates from patients with UC and those with CC. DAF expressed in the mucosa and excreted into the stools of UC patients is different from that expressed in CC with regard to UEA-I reactivity. Future studies should be directed toward determining whether a qualitatively unique isoform of DAF is present, of which sugar chains are specific to CC in UC patients.

Simultaneous identification of DNA and RNA viruses present in pig faeces using process-controlled deep sequencing.

PubMed

Sachsenröder, Jana; Twardziok, Sven; Hammerl, Jens A; Janczyk, Pawel; Wrede, Paul; Hertwig, Stefan; Johne, Reimar

2012-01-01

Animal faeces comprise a community of many different microorganisms including bacteria and viruses. Only scarce information is available about the diversity of viruses present in the faeces of pigs. Here we describe a protocol, which was optimized for the purification of the total fraction of viral particles from pig faeces. The genomes of the purified DNA and RNA viruses were simultaneously amplified by PCR and subjected to deep sequencing followed by bioinformatic analyses. The efficiency of the method was monitored using a process control consisting of three bacteriophages (T4, M13 and MS2) with different morphology and genome types. Defined amounts of the bacteriophages were added to the sample and their abundance was assessed by quantitative PCR during the preparation procedure. The procedure was applied to a pooled faecal sample of five pigs. From this sample, 69,613 sequence reads were generated. All of the added bacteriophages were identified by sequence analysis of the reads. In total, 7.7% of the reads showed significant sequence identities with published viral sequences. They mainly originated from bacteriophages (73.9%) and mammalian viruses (23.9%); 0.8% of the sequences showed identities to plant viruses. The most abundant detected porcine viruses were kobuvirus, rotavirus C, astrovirus, enterovirus B, sapovirus and picobirnavirus. In addition, sequences with identities to the chimpanzee stool-associated circular ssDNA virus were identified. Whole genome analysis indicates that this virus, tentatively designated as pig stool-associated circular ssDNA virus (PigSCV), represents a novel pig virus. The established protocol enables the simultaneous detection of DNA and RNA viruses in pig faeces including the identification of so far unknown viruses. It may be applied in studies investigating aetiology, epidemiology and ecology of diseases. The implemented process control serves as quality control, ensures comparability of the method and may be used for

Detection of Norovirus by BD MAX™, Xpert® Norovirus, and xTAG® Gastrointestinal Pathogen Panel in stool and vomit samples.

PubMed

McHugh, Martin P; Guerendiain, Daniel; Hardie, Alison; Kenicer, Juliet; MacKenzie, Laura; Templeton, Kate E

2018-06-08

Norovirus is a leading cause of infectious gastroenteritis, characterized by outbreaks of diarrhoea and vomiting in closed settings. Nucleic acid amplification tests allow rapid and sensitive laboratory diagnosis of norovirus, with a number of commercial platforms now available. Evaluate the performance of the Becton Dickinson BD-MAX™System, Cepheid Xpert® Norovirus Assay, and Luminex xTAG® Gastrointestinal Pathogen Panel (GPP) for norovirus detection in stool. Assess the performance of the Xpert® Norovirus Assay and BD-MAX™ in vomit samples. 163 diarrhoeal stool samples were tested on four diagnostic systems (laboratory-defined real time RT-PCR (assigned as gold standard), BD MAX™, Xpert® Norovirus Assay, and xTAG® GPP). A further 70 vomit samples were tested on the Xpert and BD MAX platforms. In stool, sensitivity and specificity of the BD-MAX™ was 96.8% and 100%, for Xpert® Norovirus Assay was 91.9% and 100%, and for xTAG® GPP was 79.0% and 87.1%. In vomit samples positive and negative percent agreement was 95.6% and 92.0%, between the BD-MAX™ and Xpert® Norovirus. The BD-MAX™ System with user defined settings and the Xpert® Norovirus Assay showed acceptable sensitivity and specificity for detection of norovirus from stool and vomit. The xTAG GPP assay was less reliable for norovirus detection but can detect a number of other clinically useful enteropathogens. Clinical laboratories must consider skill mix, budget, and sample throughput to determine the best fit for their service. Copyright © 2018 Elsevier B.V. All rights reserved.

From Stool Transplants to Next-generation Microbiota Therapeutics

PubMed Central

2014-01-01

The epidemic of Clostridium difficile infection fueled by new virulent strains of the organism has led to increased use of fecal microbiota transplantation (FMT). The procedure is effective for even the most desperate cases, after failure of multiple courses of antibiotics. The approach recognizes microbiota to be integral to normal human physiology, and microbiota being used in FMT represents a new class of therapeutics. Imbalance in the composition and altered activity of the microbiota are associated with many diseases. Consequently, there is growing interest in applying FMT to non-C. difficile indications. However, this may succeed only if microbiota therapeutics are developed systematically, based on mechanistic understanding, and applying updo-date principles of microbial ecology. We discuss two pathways in development of this new therapeutic class: whole microbial communities separated from donor stool and an assembly of specific fecal microorganisms grown in vitro. PMID:24412527

Isolation of human genomic DNA for genetic analysis from premature neonates: a comparison between newborn dried blood spots, whole blood and umbilical cord tissue

PubMed Central

2013-01-01

Background Genotyping requires biological sample collection that must be reliable, convenient and acceptable for patients and clinicians. Finding the most optimal procedure of sample collection for premature neonates who have a very limited blood volume is a particular challenge. The aim of the current study was to evaluate the use of umbilical cord (UC) tissue and newborn dried blood spot (DBS)-extracted genomic DNA (gDNA) as an alternative to venous blood-derived gDNA from premature neonates for molecular genetic analysis. All samples were obtained from premature newborn infants between 24-32 weeks of gestation. Paired blood and UC samples were collected from 31 study participants. gDNA was extracted from ethylenediaminetetraacetic acid (EDTA) anticoagulant-treated blood samples (~500 μl) and newborn DBSs (n = 723) using QIAamp DNA Micro kit (Qiagen Ltd., Crawley, UK); and from UC using Qiagen DNAeasy Blood and Tissue kit (Qiagen Ltd., Crawley, UK). gDNA was quantified and purity confirmed by measuring the A260:A280 ratio. PCR amplification and pyrosequencing was carried out to determine suitability of the gDNA for molecular genetic analysis. Minor allele frequency of two unrelated single nucleotide polymorphisms (SNPs) was calculated using the entire cohort. Results Both whole blood samples and UC tissue provided good quality and yield of gDNA, which was considerably less from newborn DBS. The gDNA purity was also reduced after 3 years of storage of the newborn DBS. PCR amplification of three unrelated genes resulted in clear products in all whole blood and UC samples and 86%-100% of newborn DBS. Genotyping using pyrosequencing showed 100% concordance in the paired UC and whole blood samples. Minor allele frequencies of the two SNPs indicated that no maternal gDNA contamination occurred in the genotyping of the UC samples. Conclusions gDNAs from all three sources are suitable for standard PCR and pyrosequencing assays. Given that UC provide good quality

A comparative analysis of preservation techniques for the optimal molecular detection of hookworm DNA in a human fecal specimen

PubMed Central

Pilotte, Nils; Baumer, Ben; Grant, Jessica; Asbjornsdottir, Kristjana; Schaer, Fabian; Hu, Yan; Aroian, Raffi; Walson, Judd; Williams, Steven A.

2018-01-01

Background Proper collection and storage of fecal samples is necessary to guarantee the subsequent reliability of DNA-based soil-transmitted helminth diagnostic procedures. Previous research has examined various methods to preserve fecal samples for subsequent microscopic analysis or for subsequent determination of overall DNA yields obtained following DNA extraction. However, only limited research has focused on the preservation of soil-transmitted helminth DNA in stool samples stored at ambient temperature or maintained in a cold chain for extended periods of time. Methodology Quantitative real-time PCR was used in this study as a measure of the effectiveness of seven commercially available products to preserve hookworm DNA over time and at different temperatures. Results were compared against “no preservative” controls and the “gold standard” of rapidly freezing samples at -20°C. The preservation methods were compared at both 4°C and at simulated tropical ambient temperature (32°C) over a period of 60 days. Evaluation of the effectiveness of each preservative was based on quantitative real-time PCR detection of target hookworm DNA. Conclusions At 4°C there were no significant differences in DNA amplification efficiency (as measured by Cq values) regardless of the preservation method utilized over the 60-day period. At 32°C, preservation with FTA cards, potassium dichromate, and a silica bead two-step desiccation process proved most advantageous for minimizing Cq value increases, while RNA later, 95% ethanol and Paxgene also demonstrate some protective effect. These results suggest that fecal samples spiked with known concentrations of hookworm-derived egg material can remain at 4°C for 60 days in the absence of preservative, without significant degradation of the DNA target. Likewise, a variety of preservation methods can provide a measure of protection in the absence of a cold chain. As a result, other factors, such as preservative toxicity

Performance evaluation of direct saline stool microscopy, Formol ether concentration and Kato Katz diagnostic methods for intestinal parasitosis in the absence of gold standard methods.

PubMed

Hailu, Tadesse; Abera, Bayeh

2015-07-01

The parasite load within the sample and the amount of sample taken during examination greatly compromise the sensitivity of direct saline stool microscopy. A cross-sectional study was conducted in March 2011 in Bahir Dar city among 778 fresh single stool samples to evaluate the performance of direct saline (DS), Kato Katz (KK) and Formol ether concentration (FEC) methods against the 'Gold' standard. Among 778 stool samples from school age children, the highest prevalence of intestinal parasites was recorded by FEC (55.1%). The sensitivity of DS, FEC and KK were 61.1%, 92.3% and 58.7%, respectively. FEC is more sensitive than DS and KK. Hence, use of the latter is preferred. © The Author(s) 2015.

Comparative Evaluation of Three Methods (Microscopic Examination, Direct Fluorescent Antibody Assay, and Immunochromatographic Method) for the Diagnosis of Giardia intestinalis From Stool Specimens.

PubMed

Karadam, Senem Yaman; Ertuğ, Sema; Ertabaklar, Hatice

2016-03-01

The aim of this study was to compare direct microscopic examination, direct fluorescent antibody assay (DFA), and the immunochromatographic method (IK) and identify the best suitable method for the diagnosis of Giardia intestinalis. In this study, 25 stool samples that had been diagnosed as being infected with G. intestinalis using the native-Lugol and/or formol-ethyl acetate concentration method and 25 non-parasite-infected samples (the control group) were examined. After microscopic examination of stools, they were kept at -20°C for examination using DFA and IK. Stool samples were studied using DFA (CeLLabs, Crypto/Giardia-Cel IF) and IK (RIDA QUICK, Cryptosporidium/Giardia Combi Dipstick), as per the manufacturers' instructions. In our study, using the DFA method, parasites were detected in all 25 stool samples in which G. intestinalis was diagnosed by direct microscopic examination. Using the IK method, a particular band indicative of the parasite was detected in 24 samples. No parasites were detected in all 25 samples in the control group. Thus, when direct microscopic examination is taken as reference, the senstivity and specificity of DFA for the diagnosis of G. intestinalis were found to be 100% each, while those of IK were found to be 96% and 100%, respectively.

Dipstick Test for Rapid Diagnosis of Shigella dysenteriae 1 in Bacterial Cultures and Its Potential Use on Stool Samples

PubMed Central

Taneja, Neelam; Nato, Faridabano; Dartevelle, Sylvie; Sire, Jean Marie; Garin, Benoit; Thi Phuong, Lan Nguyen; Diep, Tai The; Shako, Jean Christophe; Bimet, François; Filliol, Ingrid; Muyembe, Jean-Jacques; Ungeheuer, Marie Noëlle; Ottone, Catherine; Sansonetti, Philippe; Germani, Yves

2011-01-01

Background We describe a test for rapid detection of S. dysenteriae 1 in bacterial cultures and in stools, at the bedside of patients. Methodology/Principal Findings The test is based on the detection of S. dysenteriae 1 lipopolysaccharide (LPS) using serotype 1-specific monoclonal antibodies coupled to gold particles and displayed on a one-step immunochromatographic dipstick. A concentration as low as 15 ng/ml of LPS was detected in distilled water and in reconstituted stools in 10 minutes. In distilled water and in reconstituted stools, an unequivocal positive reaction was obtained with 1.6×106 CFU/ml and 4.9×106 CFU/ml of S. dysenteriae 1, respectively. Optimal conditions to read the test have been determined to limit the risk of ambiguous results due to appearance of a faint yellow test band in some negative samples. The specificity was 100% when tested with a battery of Shigella and unrelated strains in culture. When tested on 328 clinical samples in India, Vietnam, Senegal and France by laboratory technicians and in Democratic Republic of Congo by a field technician, the specificity (312/316) was 98.7% (95% CI:96.6–99.6%) and the sensitivity (11/12) was 91.7% (95% CI:59.8–99.6%). Stool cultures and the immunochromatographic test showed concordant results in 98.4 % of cases (323/328) in comparative studies. Positive and negative predictive values were 73.3% (95% CI:44.8–91.1%) and 99.7% (95% CI:98–100%). Conclusion The initial findings presented here for a simple dipstick-based test to diagnose S. dysenteriae 1 demonstrates its promising potential to become a powerful tool for case management and epidemiological surveys. PMID:21984895

Ruthenium(II) piano stool coordination compounds with aminomethylphosphanes: Synthesis, characterisation and preliminary biological study in vitro.

PubMed

Płotek, Michał; Starosta, Radosław; Komarnicka, Urszula K; Skórska-Stania, Agnieszka; Kołoczek, Przemysław; Kyzioł, Agnieszka

2017-05-01

Reaction of {[Ru(η 6 -p-cymene)Cl] 2 (μ-Cl) 2 } (1) with aminomethylphosphane derived from morpholine (P{CH 2 N(CH 2 CH 2 ) 2 O} 3 (A), PPh 2 {CH 2 N(CH 2 CH 2 ) 2 O} (B)) or piperazine (P{CH 2 N(CH 2 CH 2 ) 2 NCH 2 CH 3 } 3 (C), PPh 2 {CH 2 N(CH 2 CH 2 ) 2 NCH 2 CH 3 } (D)) results in four new piano stool ruthenium(II) coordination compounds: [Ru(η 6 -p-cymene)Cl 2 (A)] (2A), [Ru(η 6 -p-cymene)Cl 2 (B)] (2B), [Ru(η 6 -p-cymene)Cl 2 (C)] (2C) and [Ru(η 6 -p-cymene)Cl 2 (D)] (2D). Every complex was fully characterized using spectroscopic methods ( 1 H, 13 C{ 1 H}, 31 P{ 1 H} NMR and ESI-MS), elemental analysis, X-ray single crystal diffraction and DFT calculations. Preliminary studies of in vitro cytotoxicity on the A549 (human lung adenocarcinoma) and MCF7 (human breast adenocarcinoma) cell lines revealed 2A-2D activity in the same order of magnitude as in the case of cisplatin. Additionally, the study confirmed the ability of 2A-2D to interact with DNA helix and transferrin. Copyright © 2017 Elsevier Inc. All rights reserved.

Hollow silica microspheres for buoyancy-assisted separation of infectious pathogens from stool.

PubMed

Weigum, Shannon E; Xiang, Lichen; Osta, Erica; Li, Linying; López, Gabriel P

2016-09-30

Separation of cells and microorganisms from complex biological mixtures is a critical first step in many analytical applications ranging from clinical diagnostics to environmental monitoring for food and waterborne contaminants. Yet, existing techniques for cell separation are plagued by high reagent and/or instrumentation costs that limit their use in many remote or resource-poor settings, such as field clinics or developing countries. We developed an innovative approach to isolate infectious pathogens from biological fluids using buoyant hollow silica microspheres that function as "molecular buoys" for affinity-based target capture and separation by floatation. In this process, antibody functionalized glass microspheres are mixed with a complex biological sample, such as stool. When mixing is stopped, the target-bound, low-density microspheres float to the air/liquid surface, which simultaneously isolates and concentrates the target analytes from the sample matrix. The microspheres are highly tunable in terms of size, density, and surface functionality for targeting diverse analytes with separation times of ≤2min in viscous solutions. We have applied the molecular buoy technique for isolation of a protozoan parasite that causes diarrheal illness, Cryptosporidium, directly from stool with separation efficiencies over 90% and low non-specific binding. This low-cost method for phenotypic cell/pathogen separation from complex mixtures is expected to have widespread use in clinical diagnostics as well as basic research. Copyright © 2016 Elsevier B.V. All rights reserved.

Discontinuation of reflex testing of stool samples for vancomycin-resistant enterococci resulted in increased prevalence.

PubMed

Bodily, Mandy; McMullen, Kathleen M; Russo, Anthony J; Kittur, Nupur D; Hoppe-Bauer, Joan; Warren, David K

2013-08-01

Discontinuation of reflex testing of stool submitted for Clostridium difficile testing for vancomycin-resistant enterococci (VRE) led to an increase in the number of patients with healthcare-associated VRE bacteremia and bacteriuria (0.21 vs 0.36 cases per 1,000 patient-days; P<.01). Cost-benefit analysis showed reflex screening and isolation of VRE reduced hospital costs.

Comparison of the Compositions of the Stool Microbiotas of Infants Fed Goat Milk Formula, Cow Milk-Based Formula, or Breast Milk

PubMed Central

Lawley, Blair; Munro, Karen; Gowri Pathmanathan, Siva; Zhou, Shao J.; Makrides, Maria; Gibson, Robert A.; Sullivan, Thomas; Prosser, Colin G.; Lowry, Dianne; Hodgkinson, Alison J.

2013-01-01

The aim of the study was to compare the compositions of the fecal microbiotas of infants fed goat milk formula to those of infants fed cow milk formula or breast milk as the gold standard. Pyrosequencing of 16S rRNA gene sequences was used in the analysis of the microbiotas in stool samples collected from 90 Australian babies (30 in each group) at 2 months of age. Beta-diversity analysis of total microbiota sequences and Lachnospiraceae sequences revealed that they were more similar in breast milk/goat milk comparisons than in breast milk/cow milk comparisons. The Lachnospiraceae were mostly restricted to a single species (Ruminococcus gnavus) in breast milk-fed and goat milk-fed babies compared to a more diverse collection in cow milk-fed babies. Bifidobacteriaceae were abundant in the microbiotas of infants in all three groups. Bifidobacterium longum, Bifidobacterium breve, and Bifidobacterium bifidum were the most commonly detected bifidobacterial species. A semiquantitative PCR method was devised to differentiate between B. longum subsp. longum and B. longum subsp. infantis and was used to test stool samples. B. longum subsp. infantis was seldom present in stools, even of breast milk-fed babies. The presence of B. bifidum in the stools of breast milk-fed infants at abundances greater than 10% of the total microbiota was associated with the highest total abundances of Bifidobacteriaceae. When Bifidobacteriaceae abundance was low, Lachnospiraceae abundances were greater. New information about the composition of the fecal microbiota when goat milk formula is used in infant nutrition was thus obtained. PMID:23455335

Comparison of the compositions of the stool microbiotas of infants fed goat milk formula, cow milk-based formula, or breast milk.

PubMed

Tannock, Gerald W; Lawley, Blair; Munro, Karen; Gowri Pathmanathan, Siva; Zhou, Shao J; Makrides, Maria; Gibson, Robert A; Sullivan, Thomas; Prosser, Colin G; Lowry, Dianne; Hodgkinson, Alison J

2013-05-01

The aim of the study was to compare the compositions of the fecal microbiotas of infants fed goat milk formula to those of infants fed cow milk formula or breast milk as the gold standard. Pyrosequencing of 16S rRNA gene sequences was used in the analysis of the microbiotas in stool samples collected from 90 Australian babies (30 in each group) at 2 months of age. Beta-diversity analysis of total microbiota sequences and Lachnospiraceae sequences revealed that they were more similar in breast milk/goat milk comparisons than in breast milk/cow milk comparisons. The Lachnospiraceae were mostly restricted to a single species (Ruminococcus gnavus) in breast milk-fed and goat milk-fed babies compared to a more diverse collection in cow milk-fed babies. Bifidobacteriaceae were abundant in the microbiotas of infants in all three groups. Bifidobacterium longum, Bifidobacterium breve, and Bifidobacterium bifidum were the most commonly detected bifidobacterial species. A semiquantitative PCR method was devised to differentiate between B. longum subsp. longum and B. longum subsp. infantis and was used to test stool samples. B. longum subsp. infantis was seldom present in stools, even of breast milk-fed babies. The presence of B. bifidum in the stools of breast milk-fed infants at abundances greater than 10% of the total microbiota was associated with the highest total abundances of Bifidobacteriaceae. When Bifidobacteriaceae abundance was low, Lachnospiraceae abundances were greater. New information about the composition of the fecal microbiota when goat milk formula is used in infant nutrition was thus obtained.

Home-Based Screening for Biliary Atresia Using Infant Stool Color Cards in Canada: Quebec Feasibility Study.

PubMed

Morinville, Véronique; Ahmed, Najma; Ibberson, Cindy; Kovacs, Lajos; Kaczorowski, Janusz; Bryan, Stirling; Collet, Jean-Paul; Schreiber, Richard

2016-04-01

Biliary atresia (BA) is a leading cause of liver failure and liver transplantation in pediatrics. BA manifests by 3 weeks of life with jaundice and pale stools. Delayed diagnosis and surgical intervention with Kasai portoenterostomy after 3 months of age is significantly associated with poor prognosis for native liver survival. A national Taiwan infant stool color card (SCC) screening program has entirely eliminated late Kasai portoenterostomy >90 days of age and improved native liver survival. A recent large-scale prospective cohort study in British Columbia, Canada, indicated that distribution of SCC on the maternity ward was feasible, led to high utilization rate, and was cost-effective. The aim of the present study was to assess the generalizability of this screening strategy in another Canadian jurisdiction with a different sociodemographic profile. An SCC was distributed to families of newborns discharged at St Mary's Hospital Center, Montreal, Quebec. Families were instructed to monitor their infant's stool color for 21 days and then complete and mail the SCC to the study center. Phone surveys to families who did not return cards were used to estimate total card utilization rate. Two thousand two hundred forty-six infants were eligible for inclusion; 99.9% were enrolled. Mail SCC return rate was 63.3%. No cases of BA were identified. All of the 118 families who completed the phone survey reported that they had utilized the SCC. Conservative and optimistic estimates for total card utilization rates were 82% and 100%, respectively. The high enrollment and utilization rates in this screening study strongly support the feasibility of implementing a Canadian SCC screening program to improve outcomes of children with BA.

Repeated stool sampling and use of multiple techniques enhance the sensitivity of helminth diagnosis: a cross-sectional survey in southern Lao People's Democratic Republic.

PubMed

Sayasone, Somphou; Utzinger, Jürg; Akkhavong, Kongsap; Odermatt, Peter

2015-01-01

Intestinal parasitic infections are common in Lao People's Democratic Republic (Lao PDR). We investigated the accuracy of the Kato-Katz (KK) technique in relation to varying stool sampling efforts, and determined the effect of the concurrent use of a quantitative formalin-ethyl acetate concentration technique (FECT) for helminth diagnosis and appraisal of concomitant infections. The study was carried out between March and May 2006 in Champasack province, southern Lao PDR. Overall, 485 individuals aged ≥6 months who provided three stool samples were included in the final analysis. All stool samples were subjected to the KK technique. Additionally, one stool sample per individual was processed by FECT. Diagnosis was done under a light microscope by experienced laboratory technicians. Analysis of three stool samples with KK plus a single FECT was considered as diagnostic 'gold' standard and resulted in prevalence estimates of hookworm, Opisthorchis viverrini, Ascaris lumbricoides, Trichuris trichiura and Schistosoma mekongi infection of 77.9%, 65.0%, 33.4%, 26.2% and 24.3%, respectively. As expected, a single KK and a single FECT missed a considerable number of infections. While our diagnostic 'gold' standard produced similar results than those obtained by a mathematical model for most helminth infections, the 'true' prevalence predicted by the model for S. mekongi (28.1%) was somewhat higher than after multiple KK plus a single FECT (24.3%). In the current setting, triplicate KK plus a single FECT diagnosed helminth infections with high sensitivity. Hence, such a diagnostic approach might be utilised for generating high-quality baseline data, assessing anthelminthic drug efficacy and rigorous monitoring of community interventions. Copyright © 2014 Elsevier B.V. All rights reserved.

Development of a reverse transcription-loop-mediated isothermal amplification (RT-LAMP) system for a highly sensitive detection of enterovirus in the stool samples of acute flaccid paralysis cases.

PubMed

Arita, Minetaro; Ling, Hua; Yan, Dongmei; Nishimura, Yorihiro; Yoshida, Hiromu; Wakita, Takaji; Shimizu, Hiroyuki

2009-12-16

In the global eradication program for poliomyelitis, the laboratory diagnosis plays a critical role by isolating poliovirus (PV) from the stool samples of acute flaccid paralysis (AFP) cases. In this study, we developed a reverse transcription-loop-mediated isothermal amplification (RT-LAMP) system for a rapid and highly sensitive detection of enterovirus including PV to identify stool samples positive for enterovirus including PV. A primer set was designed for RT-LAMP to detect enterovirus preferably those with PV-like 5'NTRs of the viral genome. The sensitivity of RT-LAMP system was evaluated with prototype strains of enterovirus. Detection of enterovirus from stool extracts was examined by using RT-LAMP system. We detected at least 400 copies of the viral genomes of PV(Sabin) strains within 90 min by RT-LAMP with the primer set. This RT-LAMP system showed a preference for Human enterovirus species C (HEV-C) strains including PV, but exhibited less sensitivity to the prototype strains of HEV-A and HEV-B (detection limits of 7,400 to 28,000 copies). Stool extracts, from which PV, HEV-C, or HEV-A was isolated in the cell culture system, were mostly positive by RT-LAMP method (positive rates of 15/16 (= 94%), 13/14 (= 93%), and 4/4 (= 100%), respectively). The positive rate of this RT-LAMP system for stool extracts from which HEV-B was isolated was lower than that of HEV-C (positive rate of 11/21 (= 52%)). In the stool samples, which were negative for enterovirus isolation by the cell culture system, we found that two samples were positive for RT-LAMP (positive rates of 2/38 (= 5.3%)). In these samples, enterovirus 96 was identified by sequence analysis utilizing a seminested PCR system. RT-LAMP system developed in this study showed a high sensitivity comparable to that of the cell culture system for the detection of PV, HEV-A, and HEV-C, but less sensitivity to HEV-B. This RT-LAMP system would be useful for the direct detection of enterovirus from the stool

gbpA as a Novel qPCR Target for the Species-Specific Detection of Vibrio cholerae O1, O139, Non-O1/Non-O139 in Environmental, Stool, and Historical Continuous Plankton Recorder Samples.

PubMed

Vezzulli, Luigi; Stauder, Monica; Grande, Chiara; Pezzati, Elisabetta; Verheye, Hans M; Owens, Nicholas J P; Pruzzo, Carla

2015-01-01

The Vibrio cholerae N-acetyl glucosamine-binding protein A (GbpA) is a chitin-binding protein involved in V. cholerae attachment to environmental chitin surfaces and human intestinal cells. We previously investigated the distribution and genetic variations of gbpA in a large collection of V. cholerae strains and found that the gene is consistently present and highly conserved in this species. Primers and probe were designed from the gbpA sequence of V. cholerae and a new Taq-based qPCR protocol was developed for diagnostic detection and quantification of the bacterium in environmental and stool samples. In addition, the positions of primers targeting the gbpA gene region were selected to obtain a short amplified fragment of 206 bp and the protocol was optimized for the analysis of formalin-fixed samples, such as historical Continuous Plankton Recorder (CPR) samples. Overall, the method is sensitive (50 gene copies), highly specific for V. cholerae and failed to amplify strains of the closely-related species Vibrio mimicus. The sensitivity of the assay applied to environmental and stool samples spiked with V. cholerae ATCC 39315 was comparable to that of pure cultures and was of 102 genomic units/l for drinking and seawater samples, 101 genomic units/g for sediment and 102 genomic units/g for bivalve and stool samples. The method also performs well when tested on artificially formalin-fixed and degraded genomic samples and was able to amplify V. cholerae DNA in historical CPR samples, the earliest of which date back to August 1966. The detection of V. cholerae in CPR samples collected in cholera endemic areas such as the Benguela Current Large Marine Ecosystem (BCLME) is of particular significance and represents a proof of concept for the possible use of the CPR technology and the developed qPCR assay in cholera studies.

gbpA as a Novel qPCR Target for the Species-Specific Detection of Vibrio cholerae O1, O139, Non-O1/Non-O139 in Environmental, Stool, and Historical Continuous Plankton Recorder Samples

PubMed Central

Vezzulli, Luigi; Stauder, Monica; Grande, Chiara; Pezzati, Elisabetta; Verheye, Hans M.; Owens, Nicholas J. P.; Pruzzo, Carla

2015-01-01

The Vibrio cholerae N-acetyl glucosamine-binding protein A (GbpA) is a chitin-binding protein involved in V. cholerae attachment to environmental chitin surfaces and human intestinal cells. We previously investigated the distribution and genetic variations of gbpA in a large collection of V. cholerae strains and found that the gene is consistently present and highly conserved in this species. Primers and probe were designed from the gbpA sequence of V. cholerae and a new Taq-based qPCR protocol was developed for diagnostic detection and quantification of the bacterium in environmental and stool samples. In addition, the positions of primers targeting the gbpA gene region were selected to obtain a short amplified fragment of 206 bp and the protocol was optimized for the analysis of formalin-fixed samples, such as historical Continuous Plankton Recorder (CPR) samples. Overall, the method is sensitive (50 gene copies), highly specific for V. cholerae and failed to amplify strains of the closely-related species Vibrio mimicus. The sensitivity of the assay applied to environmental and stool samples spiked with V. cholerae ATCC 39315 was comparable to that of pure cultures and was of 102 genomic units/l for drinking and seawater samples, 101 genomic units/g for sediment and 102 genomic units/g for bivalve and stool samples. The method also performs well when tested on artificially formalin-fixed and degraded genomic samples and was able to amplify V. cholerae DNA in historical CPR samples, the earliest of which date back to August 1966. The detection of V. cholerae in CPR samples collected in cholera endemic areas such as the Benguela Current Large Marine Ecosystem (BCLME) is of particular significance and represents a proof of concept for the possible use of the CPR technology and the developed qPCR assay in cholera studies. PMID:25915771

Evaluation of Performance and Potential Clinical Impact of ProSpecT Shiga Toxin Escherichia coli Microplate Assay for Detection of Shiga Toxin-Producing E. coli in Stool Samples

PubMed Central

Gavin, Patrick J.; Peterson, Lance R.; Pasquariello, Anna C.; Blackburn, Joanna; Hamming, Mark G.; Kuo, Kuo J.; Thomson, Richard B.

2004-01-01

Shiga toxin-producing Escherichia coli bacteria (STEC) are emerging pathogens capable of producing sporadic and epidemic diarrhea, hemorrhagic colitis, and potentially life-threatening hemolytic-uremic syndrome. Although the presence of E. coli O157 can be readily detected in stool by sorbitol-MacConkey agar culture (SMAC), STEC non-O157 serotypes cannot. In contrast to culture, testing for the presence of Shiga toxins 1 and 2 in stool detects both O157 and non-O157 STEC serotypes capable of causing disease. Over two consecutive summers, we evaluated the performance of the ProSpecT Shiga toxin E. coli Microplate assay (Alexon-Trend, Ramsey, Minn.), an enzyme immunoassay for the detection of Shiga toxins 1 and 2, on all stools submitted for culture of enteric pathogens, and the potential clinical impact of Shiga toxin detection. Twenty-nine stool specimens were STEC positive by ProSpecT assay. Twenty-seven of 29 STEC-positive isolates were confirmed by SMAC and serotyping or by a second enzyme immunoassay and PCR (positive predictive value, 93%). Thirteen of 27 confirmed Shiga toxin-producing strains were serotype O157. The remaining 14 strains represented 8 other serotypes. The ProSpecT assay was 100% sensitive and specific for detection of E. coli O157 in stool (7 of 7) compared to SMAC. In addition, the ProSpecT assay detected twice as many STEC as SMAC. Fifty-two percent of confirmed STEC-positive stools were nonbloody. Thus, in our population, screening strategies that test only visibly bloody stools for STEC would miss a majority of cases. Eleven (41%) STEC-positive patients were hospitalized, and eight (30%) developed severe disease (two developed hemolytic-uremic syndrome, and six developed hemorrhagic colitis). Prior to detection of STEC infection, seven (26%) and eight patients (30%) underwent unnecessary diagnostic procedures or received potentially deleterious empirical treatment, respectively. We propose that establishing a specific diagnosis of STEC

Development and accuracy of quantitative real-time polymerase chain reaction assays for detection and quantification of enterotoxigenic Escherichia coli (ETEC) heat labile and heat stable toxin genes in travelers' diarrhea samples.

PubMed

Youmans, Bonnie P; Ajami, Nadim J; Jiang, Zhi-Dong; Petrosino, Joseph F; DuPont, Herbert L; Highlander, Sarah K

2014-01-01

Enterotoxigenic Escherichia coli (ETEC), the leading bacterial pathogen of travelers' diarrhea, is routinely detected by an established DNA hybridization protocol that is neither sensitive nor quantitative. Quantitative real-time polymerase chain reaction (qPCR) assays that detect the ETEC toxin genes eltA, sta1, and sta2 in clinical stool samples were developed and tested using donor stool inoculated with known quantities of ETEC bacteria. The sensitivity of the qPCR assays is 89%, compared with 22% for the DNA hybridization assay, and the limits of detection are 10,000-fold lower than the DNA hybridization assays performed in parallel. Ninety-three clinical stool samples, previously characterized by DNA hybridization, were tested using the new ETEC qPCR assays. Discordant toxin profiles were observed for 22 samples, notably, four samples originally typed as ETEC negative were ETEC positive. The qPCR assays are unique in their sensitivity and ability to quantify the three toxin genes in clinical stool samples.

Comparison of CHROMagar Salmonella Medium and Hektoen Enteric Agar for Isolation of Salmonellae from Stool Samples

PubMed Central

Gaillot, Olivier; Di Camillo, Patrick; Berche, Patrick; Courcol, René; Savage, Colette

1999-01-01

CHROMagar Salmonella (CAS), a new chromogenic medium, was retrospectively compared to Hektoen enteric agar (HEA) with 501 Salmonella stock isolates and was then prospectively compared to HEA for the detection and presumptive identification of Salmonella spp. with 508 stool samples before and after enrichment. All stock cultures (100%), including cultures of H2S-negative isolates, yielded typical mauve colonies on CAS, while 497 (99%) isolates produced typical lactose-negative, black-centered colonies on HEA. Following overnight incubation at 37°C, a total of 20 Salmonella strains were isolated from the 508 clinical samples. Sensitivities for primary plating and after enrichment were 95% (19 isolates) and 100% (20 isolates), respectively, for CAS and 80% (16 isolates) and 100% (20 isolates), respectively, for HEA. The specificity of CAS (88.9%) was significantly higher than that of HEA (78.5%; P < 0.0001). On the basis of its good sensitivity and specificity, CAS medium can be recommended for use for primary plating when human stool samples are screened for Salmonella spp. PMID:9986847

Steadying the Three-Legged Stool: Authorizers, Charter Schools, and Education Service Providers. Authorizing Matters. Issue Brief

ERIC Educational Resources Information Center

Lowe, Adam; Lin, Margaret

2006-01-01

A three-legged stool is always stable, regardless of its placement on an uneven surface. Keeping the top parallel to the floor and comfortable to sit on, however, requires careful steps to achieve balance among each of the three legs. In carrying out their work, authorizers typically work to achieve steadiness in a two-party accountability…

Occurrence of Thermotolerant Campylobacter in Raw Poultry Meat, Environmental and Pigeon Stools Collected in Open-Air Markets.

PubMed

Bellio, Alberto; Traversa, Amaranta; Adriano, Daniela; Bianchi, Daniela Manila; Colzani, Alberto; Gili, Stefano; Dondo, Alessandro; Gallina, Silvia; Grattarola, Carla; Maurella, Cristiana; Zoppi, Simona; Zuccon, Fabio; Decastelli, Lucia

2014-08-28

Campylobacteriosis was the most commonly reported zoonosis for confirmed human cases in European Union during 2011. Poultry meat was very often implicated in Campylobacter infections in humans. In Italy commerce of raw poultry meat is common in open-air markets: these areas can be considered at high risk of bacterial contamination due to the high presence birds like pigeons. The aim of this study was to collect data about the contamination by thermotolerant Campylobacter of raw poultry meat commercialised in open-air markets, of work-surfaces in contact with poultry meat and of pigeon stools sampled in the market areas in Turin, Northern Italy. Between September 2011 and December 2012, 86 raw poultry meat samples, 86 environmental swabs and 108 animal samples were collected in 38 open-air markets. Analysis were carried out according to ISO10272-1:2006 standard. C.coli was detected in 2.3% (2/86) of raw poultry meat samples, whereas no swab (0/86) resulted positive. Of pigeon stool 28% (30/107) was positive for C.jejuni (83.3% C.jejuni subsp . jejuni and 16.7% C.jejuni subsp . doylei ). C.jejuni subsp. jejuni was isolated from 1 dead pigeon . Our results showed lower rates of contamination than those reported at retail in Europe. Although samples were collected in areas at high risk of contamination, raw poultry meat and work surfaces reported a low level of presence of thermotolerant Campylobacter . The high percentage of C.jejuni isolated from pigeon stools showed the importance of a continuous application of preventive measures by the food business operators and the surveillance activity by the Competent Authority.

Effect of Mass Stool Examination and Mass Treatment For Decreasing Intestinal Helminth and Protozoan Infection Rates in Bolivian Children: A Cross-Sectional Study

PubMed Central

Còrdova Vidal, Claudia; Strauss, Wilma; Ikoma, Toshikazu; Endoh, Kazuo; Yamamoto, Masaharu

2016-01-01

Bolivia is one of the countries with a high intestinal helminth and protozoan infection rate. Despite the high prevalence of the parasitic infection, nationwide preventive measures for Bolivian children have not yet been implemented. We evaluated the effect of mass stool examination and treatment as a strategy for decreasing the infection rate. This study was conducted between 2013 and 2015 in children aged 2–18 years. A total of 2,033 stool samples (575 in 2013, 815 in 2014 and 642 in 2015) were collected and examined using the formalin-ether medical sedimentation method. As an anthelminthic medicine, nitazoxanide was given to all infected children within 2 months post-examination, each year. The effect of mass stool examination and treatment was evaluated based on the changes in the overall or individual parasitic infection rates during the study period. The overall parasitic infection rate decreased significantly from 65.2% in 2013 to 43.0% in 2015; a 22.2 percentage point decrease (P<0.001). Protozoan infection accounted for a large portion of the parasitic infections, in the following rates: 62.4% in 2013, 49.3% in 2014, and 41.0% in 2015. The rate of the most common helminth infection, Hymenolepis nana, decreased significantly from 9.0% in 2013 to 6.4% in 2014 to 3.4% in 2015 (P<0.001). Prevalence of the most common pathogenic protozoan infection, Entamoeba histolytica, decreased significantly from 19.0% in 2013 to 3.0% in 2015 (P<0.001). Conversely, the rate of Giardia intestinalis increased significantly from 16.5% in 2013 to 21.2% in 2015 (P<0.01). Mass stool examination and treatment for intestinal helminth and protozoan infections was effective for decreasing the overall parasitic infection rate in the study population, excluding Giardia intestinalis. Further studies on the long-term effect of mass stool examination and treatment for decreasing all intestinal parasitic infection rates in Bolivian children are needed. PMID:27923058

Effect of Mass Stool Examination and Mass Treatment For Decreasing Intestinal Helminth and Protozoan Infection Rates in Bolivian Children: A Cross-Sectional Study.

PubMed

Asai, Takao; Còrdova Vidal, Claudia; Strauss, Wilma; Ikoma, Toshikazu; Endoh, Kazuo; Yamamoto, Masaharu

2016-12-01

Bolivia is one of the countries with a high intestinal helminth and protozoan infection rate. Despite the high prevalence of the parasitic infection, nationwide preventive measures for Bolivian children have not yet been implemented. We evaluated the effect of mass stool examination and treatment as a strategy for decreasing the infection rate. This study was conducted between 2013 and 2015 in children aged 2-18 years. A total of 2,033 stool samples (575 in 2013, 815 in 2014 and 642 in 2015) were collected and examined using the formalin-ether medical sedimentation method. As an anthelminthic medicine, nitazoxanide was given to all infected children within 2 months post-examination, each year. The effect of mass stool examination and treatment was evaluated based on the changes in the overall or individual parasitic infection rates during the study period. The overall parasitic infection rate decreased significantly from 65.2% in 2013 to 43.0% in 2015; a 22.2 percentage point decrease (P<0.001). Protozoan infection accounted for a large portion of the parasitic infections, in the following rates: 62.4% in 2013, 49.3% in 2014, and 41.0% in 2015. The rate of the most common helminth infection, Hymenolepis nana, decreased significantly from 9.0% in 2013 to 6.4% in 2014 to 3.4% in 2015 (P<0.001). Prevalence of the most common pathogenic protozoan infection, Entamoeba histolytica, decreased significantly from 19.0% in 2013 to 3.0% in 2015 (P<0.001). Conversely, the rate of Giardia intestinalis increased significantly from 16.5% in 2013 to 21.2% in 2015 (P<0.01). Mass stool examination and treatment for intestinal helminth and protozoan infections was effective for decreasing the overall parasitic infection rate in the study population, excluding Giardia intestinalis. Further studies on the long-term effect of mass stool examination and treatment for decreasing all intestinal parasitic infection rates in Bolivian children are needed.

Agreement Between Home-Based Measurement of Stool Calprotectin and ELISA Results for Monitoring Inflammatory Bowel Disease Activity.

PubMed

Heida, Anke; Knol, Mariska; Kobold, Anneke Muller; Bootsman, Josette; Dijkstra, Gerard; van Rheenen, Patrick F

2017-11-01

An increasing number of physicians use repeated measurements of stool calprotectin to monitor intestinal inflammation in patients with inflammatory bowel diseases (IBDs). A lateral flow-based rapid test allows patients to measure their own stool calprotectin values at home. The test comes with a software application (IBDoc; Bühlmann Laboratories AG, Schönenbuch, Switzerland) that turns a smartphone camera into a results reader. We compared results from this method with those from the hospital-based reader (Quantum Blue; Bühlmann Laboratories AG) and enzyme-linked immunosorbent assay (ELISA) analysis. In a single-center comparison study, we asked 101 participants (10 years of age or older) in the Netherlands to perform the IBDoc measurement on stool samples collected at home, from June 2015 to October 2016. Participants then sent the residual extraction fluid and a fresh specimen from the same bowel movement to our pediatric and adult IBD center at the University Medical Center Groningen, where the level of calprotectin was measured by the Quantum Blue reader and ELISA analysis, respectively. The primary outcome was the agreement of results between IBDoc and the Quantum Blue and ELISA analyses, determined by Bland-Altman plot analysis. We received 152 IBDoc results, 138 samples of residual extraction fluid for Quantum Blue analysis, and 170 fresh stool samples for ELISA analysis. Spearman's rank correlation coefficient was 0.94 for results obtained by IBDoc vs Quantum Blue and 0.85 for results obtained by IBDoc vs ELISA. At the low range of calprotectin level (<500 μg/g), 91% of IBDoc-Quantum Blue results were within the predefined limits of agreement (±100 μg/g), and 71% of IBDoc-ELISA results were in agreement. At the high range of calprotectin level (≥500 μg/g), 81% of IBDoc-Quantum Blue results were within the predefined limits of agreement (±200 μg/g) and 64% of IBDoc-ELISA results were in agreement. Measurements of fecal levels of calprotectin

Estimation of true incidence of polio: overcoming misclassification errors due to stool culture insensitivity.

PubMed

Srinivas, V; Puliyel, Jacob M

2007-08-01

The diagnosis of polio dependents on culturing the virus in stool samples of children with AFP. Using data obtained under the "Right to Information Act" of instances where only one of the two samples was positive for polio, it was possible to estimate the sensitivity of the system to detect cases of polio. The calculations suggest that there were 1625 (95% CI 1528 to 1725) cases of polio in India in 2006 rather than the 674 reported widely!

Development of a reverse transcription-loop-mediated isothermal amplification (RT-LAMP) system for a highly sensitive detection of enterovirus in the stool samples of acute flaccid paralysis cases

PubMed Central

2009-01-01

Background In the global eradication program for poliomyelitis, the laboratory diagnosis plays a critical role by isolating poliovirus (PV) from the stool samples of acute flaccid paralysis (AFP) cases. In this study, we developed a reverse transcription-loop-mediated isothermal amplification (RT-LAMP) system for a rapid and highly sensitive detection of enterovirus including PV to identify stool samples positive for enterovirus including PV. Methods A primer set was designed for RT-LAMP to detect enterovirus preferably those with PV-like 5'NTRs of the viral genome. The sensitivity of RT-LAMP system was evaluated with prototype strains of enterovirus. Detection of enterovirus from stool extracts was examined by using RT-LAMP system. Results We detected at least 400 copies of the viral genomes of PV(Sabin) strains within 90 min by RT-LAMP with the primer set. This RT-LAMP system showed a preference for Human enterovirus species C (HEV-C) strains including PV, but exhibited less sensitivity to the prototype strains of HEV-A and HEV-B (detection limits of 7,400 to 28,000 copies). Stool extracts, from which PV, HEV-C, or HEV-A was isolated in the cell culture system, were mostly positive by RT-LAMP method (positive rates of 15/16 (= 94%), 13/14 (= 93%), and 4/4 (= 100%), respectively). The positive rate of this RT-LAMP system for stool extracts from which HEV-B was isolated was lower than that of HEV-C (positive rate of 11/21 (= 52%)). In the stool samples, which were negative for enterovirus isolation by the cell culture system, we found that two samples were positive for RT-LAMP (positive rates of 2/38 (= 5.3%)). In these samples, enterovirus 96 was identified by sequence analysis utilizing a seminested PCR system. Conclusions RT-LAMP system developed in this study showed a high sensitivity comparable to that of the cell culture system for the detection of PV, HEV-A, and HEV-C, but less sensitivity to HEV-B. This RT-LAMP system would be useful for the direct

A pilot study to understand feasibility and acceptability of stool and cord blood sample collection for a large-scale longitudinal birth cohort.

PubMed

Bailey, S R; Townsend, C L; Dent, H; Mallet, C; Tsaliki, E; Riley, E M; Noursadeghi, M; Lawley, T D; Rodger, A J; Brocklehurst, P; Field, N

2017-12-28

Few data are available to guide biological sample collection around the time of birth for large-scale birth cohorts. We are designing a large UK birth cohort to investigate the role of infection and the developing immune system in determining future health and disease. We undertook a pilot to develop methodology for the main study, gain practical experience of collecting samples, and understand the acceptability of sample collection to women in late pregnancy. Between February-July 2014, we piloted the feasibility and acceptability of collecting maternal stool, baby stool and cord blood samples from participants recruited at prolonged pregnancy and planned pre-labour caesarean section clinics at University College London Hospital. Participating women were asked to complete acceptability questionnaires. Overall, 265 women were approached and 171 (65%) participated, with ≥1 sample collected from 113 women or their baby (66%). Women had a mean age of 34 years, were primarily of white ethnicity (130/166, 78%), and half were nulliparous (86/169, 51%). Women undergoing planned pre-labour caesarean section were more likely than those who delivered vaginally to provide ≥1 sample (98% vs 54%), but less likely to provide maternal stool (10% vs 43%). Pre-sample questionnaires were completed by 110/171 women (64%). Most women reported feeling comfortable with samples being collected from their baby (<10% uncomfortable), but were less comfortable about their own stool (19% uncomfortable) or a vaginal swab (24% uncomfortable). It is possible to collect a range of biological samples from women around the time of delivery, and this was acceptable for most women. These data inform study design and protocol development for large-scale birth cohorts.

Impact of changing from staining to culture techniques on detection rates of Campylobacter spp. in routine stool samples in Chile.

PubMed

Porte, Lorena; Varela, Carmen; Haecker, Thomas; Morales, Sara; Weitzel, Thomas

2016-05-13

Campylobacter is a leading cause of bacterial gastroenteritis, but sensitive diagnostic methods such as culture are expensive and often not available in resource limited settings. Therefore, direct staining techniques have been developed as a practical and economical alternative. We analyzed the impact of replacing Campylobacter staining with culture for routine stool examinations in a private hospital in Chile. From January to April 2014, a total of 750 consecutive stool samples were examined in parallel by Hucker stain and Campylobacter culture. Isolation rates of Campylobacter were determined and the performance of staining was evaluated against culture as the gold standard. Besides, isolation rates of Campylobacter and other enteric pathogens were compared to those of past years. Campylobacter was isolated by culture in 46 of 750 (6.1 %) stool samples. Direct staining only identified three samples as Campylobacter positive and reached sensitivity and specificity values of 6.5 and 100 %, respectively. In comparison to staining-based detection rates of previous years, we observed a significant increase of Campylobacter cases in our patients. Direct staining technique for Campylobacter had a very low sensitivity compared to culture. Staining methods might lead to a high rate of false negative results and an underestimation of the importance of campylobacteriosis. With the inclusion of Campylobacter culture, this pathogen became a leading cause of intestinal infection in our patient population.

Patients with gastrointestinal complains due to enteric parasites, with reference to Entamoeba histolytica/dispar as dected by ELISA E. histolytica adhesion in stool.

PubMed

El-Kadi, Mohammad A; Dorrah, Ahmad O; Shoukry, Nahla M

2006-04-01

A total of 210 patients with gastrointestinal troubles, of both sex and a mean age of 32 +/- 6.1 years, selected from the outpatient's clinics of Al-Azhar University Hospitals. 115 (54.76%) had dysentery, 95 (45.23%) did not have dysentery, 15 (14%) suffered flatulence, 20 (9.52%) had epi-gastric pain, 19 (9.05%) had vague abdominal pain, 5 vomiting (5.2%) and 10 (4.9%) had fever. Two symptoms were in 29 (13.81%) patients and three symptoms in 12 (5.71%). Of the 210 patients, 20 (9.9%) had helminthes infection, 121 (57.6%) had intestinal protozoa and 69 (32.9%) had no parasitic infection. Of these parasite-free patients, 16 had Shigella sp. and nine had Campylobacter sp. Of the patients with intestinal protozoa, 34 (16.2%) had E. histolytica/dispar by stool examination of stained smears. By using ELISA for detection of E. histolytica adhesion in stool samples of 115 with diarrhea only 18 had true E. histolytica infection and of 3 without diarrhea only one had E. histolytica infection. Mean-while, ELISA did not cross-reacted E. coli, Giardia lamblia, Cryptosporidium parvum, Endolimax nana or Blastocystis hominis. So, ELISA for detection of E. histolytica adhesion in stool samples was more specific than microscopy and safe direction to the E. histolytica treatment. Apart from intestinal protozoan and bacteria, helminthes were seen in stool analysis. These were Schistosoma mansoni (0.95%), Capillaria sp. (0.95%), Enterobius vermicularis (1.90%) macroscopically, Hymenolepis nana (4.3%) and Ascaris lumbricoides (1.43%).

Detrimental Effect of Water Submersion of Stools on Development of Strongyloides stercoralis

PubMed Central

Anamnart, Witthaya; Pattanawongsa, Attarat; Intapan, Pewpan Maleewong; Morakote, Nimit; Janwan, Penchom; Maleewong, Wanchai

2013-01-01

Strongyloidiasis is prevalent in Thailand, yet its prevalence in the south is lower than in other parts of the country. This might be due to the long rainy season in the south resulting in stool submersion in water inhibiting worm development. In this study, the effect of water submersion of fecal samples on development of Strongyloides stercoralis was investigated. Ten ml of a 1∶5 fecal suspension were placed in 15-ml tubes, 35-mm dishes, and 90-mm dishes producing the depths of 80 mm, 11 mm and 2 mm-suspensions, respectively. The worm development was followed at 1/6, 4, 6, 8, 10, 12, 14, 16, 24, and 36 h, by determining the number of filariform larva (FL) generated from agar-plate cultures (APC). Fecal suspensions kept in tubes and 35-mm dishes showed a decline in FL yield relative to incubation time and reached zero production 14 h after incubation. In contrast, the number of FL generated from the suspension kept in 90-mm dishes remained stable up to 36 h. Cumulatively, all tubes and 35-mm dishes became negative in APC after 14 h while 90-mm dishes remained APC-positive up to 36 h. Adding more water or stool suspension to dishes resulted in a decreased number of FL. Mechanical aeration of the suspensions in tubes restored an almost normal FL yield. It appears that the atmospheric air plays a significant role in growth and development of S. stercoralis in the environment and may be one of factors which contribute to a lower prevalence of human strongyloidiasis in the south of Thailand. PMID:24358173

Comparison of a stool antigen detection kit and PCR for diagnosis of Entamoeba histolytica and Entamoeba dispar infections in asymptomatic cyst passers in Iran.

PubMed

Solaymani-Mohammadi, Shahram; Rezaian, Mostafa; Babaei, Zahra; Rajabpour, Azam; Meamar, Ahmad R; Pourbabai, Ahmad A; Petri, William A

2006-06-01

The present study was conducted to compare stool antigen detection with PCR for the diagnosis of Entamoeba sp. infection in asymptomatic cyst passers from Iran. Entamoeba dispar and, in one case, E. moshkovskii were the Entamoeba spp. found in the amebic cyst passers. There was a 100% correlation between the results from the TechLab E. histolytica II stool antigen kit and those from nested PCR. We concluded that E. dispar is much more common in asymptomatic cyst passers in Iran and that antigen detection and PCR are comparable diagnostic modalities.

Diagnosis of human fascioliasis by stool and blood techniques: update for the present global scenario.

PubMed

Mas-Coma, S; Bargues, M D; Valero, M A

2014-12-01

Before the 1990s, human fascioliasis diagnosis focused on individual patients in hospitals or health centres. Case reports were mainly from developed countries and usually concerned isolated human infection in animal endemic areas. From the mid-1990s onwards, due to the progressive description of human endemic areas and human infection reports in developing countries, but also new knowledge on clinical manifestations and pathology, new situations, hitherto neglected, entered in the global scenario. Human fascioliasis has proved to be pronouncedly more heterogeneous than previously thought, including different transmission patterns and epidemiological situations. Stool and blood techniques, the main tools for diagnosis in humans, have been improved for both patient and survey diagnosis. Present availabilities for human diagnosis are reviewed focusing on advantages and weaknesses, sample management, egg differentiation, qualitative and quantitative diagnosis, antibody and antigen detection, post-treatment monitoring and post-control surveillance. Main conclusions refer to the pronounced difficulties of diagnosing fascioliasis in humans given the different infection phases and parasite migration capacities, clinical heterogeneity, immunological complexity, different epidemiological situations and transmission patterns, the lack of a diagnostic technique covering all needs and situations, and the advisability for a combined use of different techniques, at least including a stool technique and a blood technique.

Survey of gastrointestinal reactions to foods in adults in relation to atopy, presence of mucus in the stools, swelling of joints and arthralgia in patients with gastrointestinal reactions to foods.

PubMed

Bengtsson, U; Hanson, L A; Ahlstedt, S

1996-12-01

Food intolerance in adults is mostly associated with vague symptoms and not clearly related to atopy and food allergy. A combination of different pathogenetic mechanisms may be responsible for the symptoms. The aim of this study was to describe patients with a history of food-related gastrointestinal symptoms in relation to the presence of mucus in the stools, joint swelling and arthralgia and to determine whether or not there is an association between the presence of these parameters, atopic disease and the presence of immune complexes in serum. Fifty-eight patients consecutively referred to our clinic with food-related gastrointestinal symptoms were investigated. Thirty-five patients (60%) had mucus in their stools, 24 patients (41%) complained about joint swelling and 41 patients (71%) had arthralgia. There were no correlations between these parameters and atopy according to Phadiatope test or skin prick test (SPT). No correlations were found between the occurrence of mucus in the stools, arthralgia and joint swelling. There were significantly higher levels of circulating immune complexes in patients with a history of arthralgia compared with patients with no such history (P < 0.03) and the number of individuals with the presence of such immune complexes was higher among the patients with arthralgia than among the patients without. In general the patients did not relate the exposure to certain foods to symptoms like joint swelling, arthralgia and presence of mucus in the stools. However, there were significant positive correlations between food-related gastrointestinal symptoms in the following instances: chocolate-induced gastrointestinal symptoms and mucus in the stools (P = 0.006), vegetable-induced gastrointestinal symptoms and mucus in the stools (P = 0.002) and meat-induced gastrointestinal symptoms and mucus in the stools (P = 0.003). In a group of individuals without food-related symptoms investigated separately, a very low frequency of mucus in the

Dietary Shifts May Trigger Dysbiosis and Mucous Stools in Giant Pandas (Ailuropoda melanoleuca)

PubMed Central

Williams, Candace L.; Dill-McFarland, Kimberly A.; Vandewege, Michael W.; Sparks, Darrell L.; Willard, Scott T.; Kouba, Andrew J.; Suen, Garret; Brown, Ashli E.

2016-01-01

Dietary shifts can result in changes to the gastrointestinal tract (GIT) microbiota, leading to negative outcomes for the host, including inflammation. Giant pandas (Ailuropoda melanoleuca) are physiologically classified as carnivores; however, they consume an herbivorous diet with dramatic seasonal dietary shifts and episodes of chronic GIT distress with symptoms including abdominal pain, loss of appetite and the excretion of mucous stools (mucoids). These episodes adversely affect the overall nutritional and health status of giant pandas. Here, we examined the fecal microbiota of two giant pandas’ non-mucoid and mucoid stools and compared these to samples from a previous winter season that had historically few mucoid episodes. To identify the microbiota present, we isolated and sequenced the 16S rRNA using next-generation sequencing. Mucoids occurred following a seasonal feeding switch from predominately bamboo culm (stalk) to leaves. All fecal samples displayed low diversity and were dominated by bacteria in the phyla Firmicutes and to a lesser extent, Proteobacteria. Fecal samples immediately prior to mucoid episodes had lower microbial diversity as compared to mucoids. Mucoids were mostly comprised of common mucosal-associated taxa including Streptococcus and Leuconostoc species, and exhibited increased abundance for bacteria in the family Pasteurellaceae. Taken together, these findings indicate that mucoids may represent an expulsion of the mucosal lining that is driven by changes in diet. We suggest that these occurrences serve to reset their GIT microbiota following changes in bamboo part preference, as giant pandas have retained a carnivorous GIT anatomy while shifting to an herbivorous diet. PMID:27199976

Dietary Shifts May Trigger Dysbiosis and Mucous Stools in Giant Pandas (Ailuropoda melanoleuca).

PubMed

Williams, Candace L; Dill-McFarland, Kimberly A; Vandewege, Michael W; Sparks, Darrell L; Willard, Scott T; Kouba, Andrew J; Suen, Garret; Brown, Ashli E

2016-01-01

Dietary shifts can result in changes to the gastrointestinal tract (GIT) microbiota, leading to negative outcomes for the host, including inflammation. Giant pandas (Ailuropoda melanoleuca) are physiologically classified as carnivores; however, they consume an herbivorous diet with dramatic seasonal dietary shifts and episodes of chronic GIT distress with symptoms including abdominal pain, loss of appetite and the excretion of mucous stools (mucoids). These episodes adversely affect the overall nutritional and health status of giant pandas. Here, we examined the fecal microbiota of two giant pandas' non-mucoid and mucoid stools and compared these to samples from a previous winter season that had historically few mucoid episodes. To identify the microbiota present, we isolated and sequenced the 16S rRNA using next-generation sequencing. Mucoids occurred following a seasonal feeding switch from predominately bamboo culm (stalk) to leaves. All fecal samples displayed low diversity and were dominated by bacteria in the phyla Firmicutes and to a lesser extent, Proteobacteria. Fecal samples immediately prior to mucoid episodes had lower microbial diversity as compared to mucoids. Mucoids were mostly comprised of common mucosal-associated taxa including Streptococcus and Leuconostoc species, and exhibited increased abundance for bacteria in the family Pasteurellaceae. Taken together, these findings indicate that mucoids may represent an expulsion of the mucosal lining that is driven by changes in diet. We suggest that these occurrences serve to reset their GIT microbiota following changes in bamboo part preference, as giant pandas have retained a carnivorous GIT anatomy while shifting to an herbivorous diet.

Morphologic changes of the anal sphincter musculature during and after temporary stool deviation.

PubMed

Sailer, M; Fein, M; Fuchs, K H; Bussen, D; Grun, C; Thiede, A

2001-04-01

Temporary stool deviation, using a stoma, is a well-known surgical principle to protect low colorectal or coloanal anastomoses. The purpose of this study was to evaluate any morphologic changes with regard to the anal sphincter muscles during and after temporary ileostomy. Forty-four patients with rectal carcinomas were studied prospectively. All patients underwent low anterior resection. Reconstruction was performed using either a coloanal pouch or a straight end-to-end anastomosis. A protective stoma was fashioned in all 44 patients (ileostomy n=41; colostomy n=3). Stoma closure was carried out after a median of 85 days (41-330 days). Using a standard protocol, anal-sphincter thickness [m. puborectalis, external anal sphincter (EAS) and internal anal (IAS) sphincter] was assessed by means of endoanal ultrasonography preoperatively, at the time of stoma closure, and every 3 months thereafter for 1 year. The diameter of the puborectal muscle decreased from a median preoperative value of 6.3 mm to 5.7 mm at the time of stoma closure (P=0.03). After 3 months, 6.2 mm was measured. This value remained stable for the complete follow-up period. Similar results were recorded for the EAS. The IAS thickness remained stable throughout the study period, measuring between 2.1 mm and 2.4 mm. Temporary stool deviation does lead to morphologic changes of the anal sphincter. While the smooth muscle remains unchanged, the striated counterpart undergoes atrophic transformation. However, after passage reconstruction, i.e., stoma closure, a rapid regeneration of the voluntary muscles is observed.

Comparison of culture based methods for the isolation of Clostridium difficile from stool samples in a research setting.

PubMed

Lister, Michelle; Stevenson, Emma; Heeg, Daniela; Minton, Nigel P; Kuehne, Sarah A

2014-08-01

Effective isolation of Clostridium difficile from stool samples is important in the research setting, especially where low numbers of spores/vegetative cells may be present within a sample. In this study, three protocols for stool culture were investigated to find a sensitive, cost effective and timely method of C. difficile isolation. For the initial enrichment step, the effectiveness of two different rich media, cycloserine-cefoxitin fructose broth (CCFB) and cycloserine-cefoxitin mannitol broth with taurocholate and lysozyme (CCMB-TAL) were compared. For the comparison of four different, selective solid media; Cycloserine-cefoxitin fructose agar (CCFA), Cycloserine-cefoxitin egg yolk agar (CCEY), ChromID C. difficile and tryptone soy agar (TSA) with 5% sheep's blood with and without preceding broth enrichment were used. As a means to enable differentiation between C. difficile and other fecal flora, the effectiveness of the inclusion of a pH indictor (1% Neutral Red), was also evaluated. The data derived indicated that CCFB is more sensitive than CCMB-TAL, however, the latter had an improved recovery rate. A broth enrichment step had a reduced sensitivity over direct plating. ChromID C. difficile showed the best recovery rate whereas CCEY egg yolk agar was the most sensitive of the four. The addition of 1% Neutral Red did not show sufficient colour change when added to CCEY egg yolk agar to be used as a differential medium. For a low cost, timely and sensitive method of isolating C. difficile from stool samples we recommend direct plating onto CCEY egg yolk agar after heat shock. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Use of a Novel Real-Time PCR Assay To Detect Oral Polio Vaccine Shedding and Reversion in Stool and Sewage Samples after a Mexican National Immunization Day▿

PubMed Central

Troy, Stephanie B.; Ferreyra-Reyes, Leticia; Huang, ChunHong; Mahmud, Nadim; Lee, Yu-Jin; Canizales-Quintero, Sergio; Flaster, Harry; Báez-Saldaña, Renata; García-García, Lourdes; Maldonado, Yvonne

2011-01-01

During replication, oral polio vaccine (OPV) can revert to neurovirulence and cause paralytic poliomyelitis. In individual vaccinees, it can acquire specific revertant point mutations, leading to vaccine-associated paralytic poliomyelitis (VAPP). With longer replication, OPV can mutate into vaccine-derived poliovirus (VDPV), which causes poliomyelitis outbreaks similar to those caused by wild poliovirus. After wild poliovirus eradication, safely phasing out vaccination will likely require global use of inactivated polio vaccine (IPV) until cessation of OPV circulation. Mexico, where children receive routine IPV but where OPV is given biannually during national immunization days (NIDs), provides a natural setting to study the duration of OPV circulation in a population primarily vaccinated with IPV. We developed a real-time PCR assay to detect and distinguish revertant and nonrevertant OPV serotype 1 (OPV-1), OPV-2, and OPV-3 from RNA extracted directly from stool and sewage. Stool samples from 124 children and 8 1-liter sewage samples from Orizaba, Veracruz, Mexico, collected 6 to 13 weeks after a NID were analyzed. Revertant OPV-1 was found in stool at 7 and 9 weeks, and nonrevertant OPV-2 and OPV-3 were found in stool from two children 10 weeks after the NID. Revertant OPV-1 and nonrevertant OPV-2 and -3 were detected in sewage at 6 and 13 weeks after the NID. Our real-time PCR assay was able to detect small amounts of OPV in both stool and sewage and to distinguish nonrevertant and revertant serotypes and demonstrated that OPV continues to circulate at least 13 weeks after a NID in a Mexican population routinely immunized with IPV. PMID:21411577

Helminth prevalence among adults in rural Kenya: a stool survey for soil-transmitted helminths and schistosomiasis in Nyanza province.

PubMed

Andereck, Jonathan W; Kipp, Aaron M; Ondiek, Michael; Vermund, Sten H

2014-12-01

Soil-transmitted helminth (STH) prevalence in children is high in rural southwestern Kenya, but adult prevalence data are scarce. A 2010 study of a village in Nyanza province found a pediatric STH prevalence of 44% using a direct stool-smear method. Adult STH prevalence and associated predictors was measured in the same village. Adults (≥18 years) presenting at the out-patient department of the small hospital or community outreach events completed a short questionnaire and provided stool samples. Light microscopy for ova and larvae was conducted using a stool concentration technique to improve sensitivity. Multivariable regression models were used to identify predictors of STH prevalence. Among 344 adults, STH prevalence was 15.7% (54/344). Hookworm was most common (13.1%; 45/344), followed by Ascaris lumbricoides (6.1%; 21/344) and Trichuris trichiura (0.6%; 2/344). Twelve participants (3.5%; 12/344) had multiple STHs and three (0.9%; 3/344) had Schistosoma mansoni. Female sex, older age and lower education level were significant STH predictors. Adult STH prevalence was lower than previous studies of children from the same village. Adults with the identified risk factors had a prevalence of ≥20%, which may warrant periodic, targeted deworming of adults with these risk factors given the low cost and low toxicity of anthelmintic drugs. © The Author 2014. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

An uncooked vegan diet shifts the profile of human fecal microflora: computerized analysis of direct stool sample gas-liquid chromatography profiles of bacterial cellular fatty acids.

PubMed Central

Peltonen, R; Ling, W H; Hänninen, O; Eerola, E

1992-01-01

The effect of an uncooked extreme vegan diet on fecal microflora was studied by direct stool sample gas-liquid chromatography (GLC) of bacterial cellular fatty acids and by quantitative bacterial culture by using classical microbiological techniques of isolation, identification, and enumeration of different bacterial species. Eighteen volunteers were divided randomly into two groups. The test group received an uncooked vegan diet for 1 month and a conventional diet of mixed Western type for the other month of the study. The control group consumed a conventional diet throughout the study period. Stool samples were collected. Bacterial cellular fatty acids were extracted directly from the stool samples and measured by GLC. Computerized analysis of the resulting fatty acid profiles was performed. Such a profile represents all bacterial cellular fatty acids in a sample and thus reflects its microflora and can be used to detect changes, differences, or similarities of bacterial flora between individual samples or sample groups. GLC profiles changed significantly in the test group after the induction and discontinuation of the vegan diet but not in the control group at any time, whereas quantitative bacterial culture did not detect any significant change in fecal bacteriology in either of the groups. The results suggest that an uncooked extreme vegan diet alters the fecal bacterial flora significantly when it is measured by direct stool sample GLC of bacterial fatty acids. PMID:1482187

A novel LCMSMS method for quantitative measurement of short-chain fatty acids in human stool derivatized with 12C- and 13C-labelled aniline.

PubMed

Chan, James Chun Yip; Kioh, Dorinda Yan Qin; Yap, Gaik Chin; Lee, Bee Wah; Chan, Eric Chun Yong

2017-05-10

A novel liquid chromatography tandem mass spectrometry (LCMSMS) method for the quantitative measurement of gut microbial-derived short-chain fatty acids (SCFAs) in human infant stool has been developed and validated. Baseline chromatographic resolution was achieved for 12 SCFAs (acetic, butyric, caproic, 2,2-dimethylbutyric, 2-ethylbutyric, isobutyric, isovaleric, 2-methylbutyric, 4-methylvaleric, propionic, pivalic and valeric acids) within an analysis time of 15min. A novel sequential derivatization of endogenous and spiked SCFAs in stool via 12 C- and 13 C-aniline respectively, facilitated the accurate quantitation of 12 C-aniline derivatized endogenous SCFAs based on calibration of exogenously 13 C-derivatized SCFAs. Optimized quenching of derivatization agents prior to LCMSMS analysis further reduced to negligible levels the confounding chromatographic peak due to in-line derivatization of unquenched aniline with residual acetic acid present within the LCMS system. The effect of residual acetic acid, a common LCMS modifier, in analysis of SCFAs has not been addressed in previous SCFA assays. For the first time, a total of 9 SCFAs (acetic, butyric, caproic, isobutyric, isovaleric, 2-methylbutyric, 4-methylvaleric, propionic and valeric acids) were detected and quantitated in 107 healthy infant stool samples. The abundance and diversity of SCFAs in infant stool vary temporally from 3 weeks onwards and stabilize towards the end of 12 months. This in turn reflects the maturation of infant SCFA-producing gut microbiota community. In summary, this novel method is applicable to future studies that investigate the biological roles of SCFAs in paediatric health and diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

Treatment guidelines for primary nonretentive encopresis and stool toileting refusal.

PubMed

Kuhn, B R; Marcus, B A; Pitner, S L

1999-04-15

Nonretentive encopresis refers to inappropriate soiling without evidence of fecal constipation and retention. This form of encopresis accounts for up to 20 percent of all cases. Characteristics include soiling accompanied by daily bowel movements that are normal in size and consistency. An organic cause for nonretentive encopresis is rarely identified. The medical assessment is usually normal, and signs of constipation are noticeably absent. A full developmental and behavioral assessment should be made to establish that the child is ready for intervention to correct encopresis and to identify any barriers to success, particularly disruptive behavior problems. Successful interventions depend on the presence of soft, comfortable bowel movements and addressing toilet refusal behavior. Daily scheduled positive toilet sits are recommended. Incentives may be used to reinforce successful defecation during these sits. A plan for management of stool withholding should be agreed on by the parents/caretakers and the family physician before intervention.

Comparison of individual and pooled stool samples for the assessment of intensity of Schistosoma mansoni and soil-transmitted helminth infections using the Kato-Katz technique.

PubMed

Kure, Ashenafi; Mekonnen, Zeleke; Dana, Daniel; Bajiro, Mitiku; Ayana, Mio; Vercruysse, Jozef; Levecke, Bruno

2015-09-24

Our group has recently provided a proof-of-principle for the examination of pooled stool samples using McMaster technique as a strategy for the rapid assessment of intensity of soil-transmitted helminth infections (STH, Ascaris lumbricoides, Trichuris trichiura and hookworm). In the present study we evaluated this pooling strategy for the assessment of intensity of both STH and Schistosoma mansoni infections using the Kato-Katz technique. A cross-sectional survey was conducted in 360 children aged 5-18 years from six schools in Jimma Zone (southwest Ethiopia). We performed faecal egg counts (FECs) in both individual and pooled samples (pools sizes of 5, 10 and 20) to estimate the number of eggs per gram of stool (EPG) using the Kato-Katz technique. We also assessed the time to screen both individual and pooled samples. Except for hookworms, there was a significant correlation (correlation coefficient = 0.53-0.95) between the mean of individual FECs and the FECs of pooled samples for A. lumbricoides, T. trichiura and S. mansoni, regardless of the pool size. Mean FEC were 2,596 EPG, 125 EPG, 47 EPG, and 41 EPG for A. lumbricoides, T. trichiura, S. mansoni and hookworm, respectively. There was no significant difference in FECs between the examination of individual and pooled stool samples, except for hookworms. For this STH, pools of 10 resulted in a significant underestimation of infection intensity. The total time to obtain individual FECs was 65 h 5 min. For pooled FECs, this was 19 h 12 min for pools of 5, 14 h 39 min for pools of 10 and 12 h 42 min for pools of 20. The results indicate that pooling of stool sample holds also promise as a rapid assessment of infections intensity for STH and S. mansoni using the Kato-Katz technique. In this setting, the time in the laboratory was reduced by 70 % when pools of 5 instead of individual stool samples were screened.

Estimating the sensitivity and specificity of Kato-Katz stool examination technique for detection of hookworms, Ascaris lumbricoides and Trichuris trichiura infections in humans in the absence of a 'gold standard'.

PubMed

Tarafder, M R; Carabin, H; Joseph, L; Balolong, E; Olveda, R; McGarvey, S T

2010-03-15

The accuracy of the Kato-Katz technique in identifying individuals with soil-transmitted helminth (STH) infections is limited by day-to-day variation in helminth egg excretion, confusion with other parasites and the laboratory technicians' experience. We aimed to estimate the sensitivity and specificity of the Kato-Katz technique to detect infection with Ascaris lumbricoides, hookworm and Trichuris trichiura using a Bayesian approach in the absence of a 'gold standard'. Data were obtained from a longitudinal study conducted between January 2004 and December 2005 in Samar Province, the Philippines. Each participant provided between one and three stool samples over consecutive days. Stool samples were examined using the Kato-Katz technique and reported as positive or negative for STHs. In the presence of measurement error, the true status of each individual is considered as latent data. Using a Bayesian method, we calculated marginal posterior densities of sensitivity and specificity parameters from the product of the likelihood function of observed and latent data. A uniform prior distribution was used (beta distribution: alpha=1, beta=1). A total of 5624 individuals provided at least one stool sample. One, two and three stool samples were provided by 1582, 1893 and 2149 individuals, respectively. All STHs showed variation in test results from day to day. Sensitivity estimates of the Kato-Katz technique for one stool sample were 96.9% (95% Bayesian Credible Interval [BCI]: 96.1%, 97.6%), 65.2% (60.0%, 69.8%) and 91.4% (90.5%, 92.3%), for A. lumbricoides, hookworm and T. trichiura, respectively. Specificity estimates for one stool sample were 96.1% (95.5%, 96.7%), 93.8% (92.4%, 95.4%) and 94.4% (93.2%, 95.5%), for A. lumbricoides, hookworm and T. trichiura, respectively. Our results show that the Kato-Katz technique can perform with reasonable accuracy with one day's stool collection for A. lumbricoides and T. trichiura. Low sensitivity of the Kato-Katz for detection

Oral Supplementation with Bovine Colostrum Decreases Intestinal Permeability and Stool Concentrations of Zonulin in Athletes.

PubMed

Hałasa, Maciej; Maciejewska, Dominika; Baśkiewicz-Hałasa, Magdalena; Machaliński, Bogusław; Safranow, Krzysztof; Stachowska, Ewa

2017-04-08

Increased intestinal permeability has been implicated in various pathologies, has various causes, and can develop during vigorous athletic training. Colostrum bovinum is a natural supplement with a wide range of supposed positive health effects, including reduction of intestine permeability. We assessed influence of colostrum supplementation on intestinal permeability related parameters in a group of 16 athletes during peak training for competition. This double-blind placebo-controlled study compared supplementation for 20 days with 500 mg of colostrum bovinum or placebo (whey). Gut permeability status was assayed by differential absorption of lactulose and mannitol (L/M test) and stool zonulin concentration. Baseline L/M tests found that six of the participants (75%) in the colostrum group had increased intestinal permeability. After supplementation, the test values were within the normal range and were significantly lower than at baseline. The colostrum group Δ values produced by comparing the post-intervention and baseline results were also significantly lower than the placebo group Δ values. The differences in stool zonulin concentration were smaller than those in the L/M test, but were significant when the Δ values due to intervention were compared between the colostrum group and the placebo group. Colostrum bovinum supplementation was safe and effective in decreasing of intestinal permeability in this series of athletes at increased risk of its elevation.

Comparative effects of single-dose ceftriaxone versus three oral antibiotic regimens on stool colonization by resistant bacilli in children.

PubMed

Toltzis, Philip; Dul, Michael; O'Riordan, Mary Ann; Toltzis, Hasida; Blumer, Jeffrey L

2007-01-01

The use of short-term intramuscular ceftriaxone for pediatric ambulatory conditions raises concerns regarding the promotion of resistance among colonizing enteric bacteria. This study was designed to assess the prevalence of stool colonization with resistant Gram-negative bacilli after single-dose ceftriaxone treatment compared with other regimens for acute otitis media. Children age 3 months to 7 years and diagnosed with acute otitis media were randomized to receive treatment with single-dose ceftriaxone or with oral cefprozil, amoxicillin or azithromycin. Stool samples were obtained at enrollment and then 3-5 days, 10-14 days, and 28-30 days after therapy was initiated and screened for the presence of facultative Gram-negative bacilli resistant to ceftriaxone, cefprozil, amoxicillin, piperacillin, piperacillin-tazobactam and tobramycin. Mean prevalence of colonization by resistant organisms for each treatment group was compared at each time point. One thousand nine subjects were enrolled. The prevalence of colonization by a Gram-negative bacillus resistant to at least 1 of the screening antibiotics decreased after receipt of ceftriaxone but returned close to values measured at study entry by 30 days. A qualitatively similar pattern was noted for the 3 other regimens, but a quantitatively greater decrease in the prevalence of colonization by a resistant bacterium was noted at the 3- to 5-day and 10- to 14-day visits among azithromycin recipients (P < 0.001). Colonization by a Gram-negative bacillus resistant specifically to ceftriaxone was unusual at each study visit, regardless of treatment assignment. A single intramuscular dose of ceftriaxone had a similar effect on the prevalence of antibiotic-resistant Gram-negative facultative bacilli in the stool of healthy children when compared with commonly used oral agents.

Normal tissue complication probability (NTCP) models for late rectal bleeding, stool frequency and fecal incontinence after radiotherapy in prostate cancer patients.

PubMed

Schaake, Wouter; van der Schaaf, Arjen; van Dijk, Lisanne V; Bongaerts, Alfons H H; van den Bergh, Alfons C M; Langendijk, Johannes A

2016-06-01

Curative radiotherapy for prostate cancer may lead to anorectal side effects, including rectal bleeding, fecal incontinence, increased stool frequency and rectal pain. The main objective of this study was to develop multivariable NTCP models for these side effects. The study sample was composed of 262 patients with localized or locally advanced prostate cancer (stage T1-3). Anorectal toxicity was prospectively assessed using a standardized follow-up program. Different anatomical subregions within and around the anorectum were delineated. A LASSO logistic regression analysis was used to analyze dose volume effects on toxicity. In the univariable analysis, rectal bleeding, increase in stool frequency and fecal incontinence were significantly associated with a large number of dosimetric parameters. The collinearity between these predictors was high (VIF>5). In the multivariable model, rectal bleeding was associated with the anorectum (V70) and anticoagulant use, fecal incontinence was associated with the external sphincter (V15) and the iliococcygeal muscle (V55). Finally, increase in stool frequency was associated with the iliococcygeal muscle (V45) and the levator ani (V40). No significant associations were found for rectal pain. Different anorectal side effects are associated with different anatomical substructures within and around the anorectum. The dosimetric variables associated with these side effects can be used to optimize radiotherapy treatment planning aiming at prevention of specific side effects and to estimate the benefit of new radiation technologies. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Rapid automated method for screening of enteric pathogens from stool specimens.

PubMed Central

Villasante, P A; Agulla, A; Merino, F J; Pérez, T; Ladrón de Guevara, C; Velasco, A C

1987-01-01

A total of 800 colonies suggestive of Salmonella, Shigella, or Yersinia species isolated on stool differential agar media were inoculated onto both conventional biochemical test media (triple sugar iron agar, urea agar, and phenylalanine agar) and Entero Pathogen Screen cards of the AutoMicrobic system (Vitek Systems, Inc., Hazelwood, Mo.). Based on the conventional tests, the AutoMicrobic system method yielded the following results: 587 true-negatives, 185 true-positives, 2 false-negatives, and 26 false-positives (sensitivity, 99%; specificity, 96%). Both true-positive and true-negative results were achieved considerably earlier than false results (P less than 0.001). The Entero Pathogen Screen card method is a fast, easy, and sensitive method for screening for Salmonella, Shigella, or Yersinia species. The impossibility of screening for oxidase-positive pathogens is a minor disadvantage of this method. PMID:3553230

Ethnicity and Prostate Cancer: Vitamin D Genetic and Sociodemographic Factors

DTIC Science & Technology

2009-03-01

polymorphisms and two SRD5A2 polymorphisms were genotyped: CDX2 (rs17883968; G/A) in the VDR promoter region and FokI (rs10735810; C/T) in VDR exon 2...and V89L (rs523349) and A49T (rs9282858) in exon 1 of the SRD5A2 gene. DNA for genotyping was extracted from blood samples using a QIAamp blood kit...and CYP3A4 . Hum Hered 2002;54:13^21. 33. John EM, Schwartz GG, Koo J, van den Berg D, Ingles SA. Sun exposure, vitamin D receptor gene polymorphisms

Molecular markers for colorectal cancer screening

PubMed Central

Dickinson, Brandon T.; Kisiel, John; Ahlquist, David A.; Grady, William M.

2016-01-01

Colorectal cancer (CRC), although a significant cause of morbidity and mortality worldwide, has seen a declining incidence and mortality in countries with programmatic screening. Fecal occult blood testing (FOBT) and endoscopic approaches are the predominant screening methods currently. The discovery of the adenoma→carcinoma sequence and a greater understanding of the genetic and epigenetic changes that drive the formation of CRC have contributed to innovative research to identify molecular markers for highly accurate, non-invasive screening tests for CRC. DNA, proteins, messenger RNA, and micro-RNA have all been evaluated. The observation of tumor cell exfoliation into the mucocellular layer of the colonic epithelium and proven stability of DNA in a harsh stool environment make stool DNA a particularly promising marker. The development of a clinically useful stool DNA test has required numerous technical advances, including optimization in DNA stabilization, the development of assays with high analytical sensitivity, and the identification of specific and broadly informative molecular markers. A multi-target stool DNA (MT-sDNA) test, which combines both mutant and methylated DNA markers and a fecal immunochemical test (FIT), recently performed favorably in a large cross-sectional validation study and has been approved by the US Food and Drug Administration (FDA) for the screening of asymptomatic, average risk individuals. The ultimate way in which molecular marker screening assays will be used in clinical practice will require additional studies to determine optimal screening intervals, factors affecting compliance, management of false positive results, and the use of these assays in high-risk populations, as well as other considerations. PMID:25994221

Exploring the concurrent presence of hepatitis A virus genome in serum, stool, saliva, and urine samples of hepatitis A patients.

PubMed

Joshi, Madhuri S; Bhalla, Shilpa; Kalrao, Vijay R; Dhongade, Ramchandra K; Chitambar, Shobha D

2014-04-01

The use of saliva and urine as an alternative to serum samples for detection of anti-hepatitis A virus (HAV) IgM antibodies has been documented. However, these samples remain underreported or unexplored for shedding of HAV. To address this issue, paired serum, stool, saliva, and urine samples collected from hepatitis A patients were screened by reverse transcription polymerase chain reaction for detection of HAV RNA. HAV RNA was detected in 67.6% (44/65), 52.3% (34/65), 8.7% (5/57), and 12.3% (8/65) of the serum, stool, saliva, and urine samples, respectively. Phylogenetic analysis of nucleotide sequences obtained for partial RNA polymerase region grouped HAV strains from all of the clinical samples of the study in subgenotype IIIA. Low frequency of HAV nucleic acid in saliva and urine samples indicates limited utility of these samples in genomic studies on HAV but suggests its potential for transmission and infection of hepatitis A. Copyright © 2014 Elsevier Inc. All rights reserved.

Clinical and Analytical Evaluation of a Single-Vial Stool Collection Device with Formalin-Free Fixative for Improved Processing and Comprehensive Detection of Gastrointestinal Parasites

PubMed Central

Couturier, Brianne A.; Jensen, Ryan; Arias, Nora; Heffron, Michael; Gubler, Elyse; Case, Kristin; Gowans, Jason

2015-01-01

Microscopic examination of feces is a standard laboratory method for diagnosing gastrointestinal parasite infections. In North America, the ovum and parasite (O&P) examination is typically performed using stool that is chemically fixed in polyvinyl alcohol (PVA) and formalin, after which the stool is concentrated by filtration to enhance sensitivity. Mini Parasep solvent-free (SF) tubes allow collection and concentration within a single collection vial. The goal of the study was to determine whether consolidated processing and concentration with the Parasep tubes using an alcohol-based fixative (Alcorfix) provide O&P examinations equivalent to or better than those done by processing of PVA-formalin-fixed stool using a SpinCon concentration device. Parasep tubes revealed filtration performance equivalent to that of the SpinCon concentration device using PVA-formalin-fixed stool containing protozoa. Specimens cocollected in Parasep tubes containing PVA-formalin and Alcorfix revealed comparable morphology and staining for various protozoa. Alcorfix effectively fixed live Cryptosporidium and microsporidia such that morphology and staining were conserved for modified acid-fast and modified trichrome stains. A work flow analysis revealed significant time savings for batches of 10 or 30 O&P specimens in tubes with Alcorfix compared to the amount of time that it took to analyze the same number of specimens in tubes with PVA-formalin. The direct hands-on time savings with Mini Parasep tubes were 17 min and 41 s and 32 min and 1 s for batches of 10 and 30 specimens, respectively. Parasep tubes containing Alcorfix provide significant work flow advantages to laboratories that process medium to high volumes of O&P specimens by streamlining processing and converting to a single tube. These improvements in work flow, reduction of the amount of formalin used in the laboratory, and equivalent microscopy results are attractive advancements in O&P testing for North American

Detection of human cytomegalovirus (CMV) DNA in feces has limited value in predicting CMV enteritis in patients with intestinal graft-versus-host disease after allogeneic stem cell transplantation.

PubMed

Sun, Y-Q; Xu, L-P; Han, T-T; Zhang, X-H; Wang, Y; Han, W; Wang, F-R; Wang, J-Z; Chen, H; Chen, Y-H; Yan, C-H; Chen, Y; Liu, K-Y; Huang, X-J

2015-10-01

Cytomegalovirus (CMV) enteritis after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is difficult to diagnose. We aimed to evaluate the sensitivity and specificity of the detection of CMV DNA in feces for predicting CMV enteritis. HSCT patients with intestinal graft-versus-host disease (GVHD) were enrolled if they met the following criteria: (i) underwent a colonoscopy and (ii) peripheral blood and feces specimens were available for CMV DNA detection within 24 h of colonoscopy. The colonoscopy histology was used as the gold standard for diagnosing CMV enteritis. Fifty-six patients underwent 58 colonoscopy examinations, and 7 were diagnosed as having CMV enteritis. Within 24 h of colonoscopy, 9 patients had detectable CMV in the feces and 19 patients had detectable CMV in the plasma, respectively. In the 7 patients with CMV enteritis, only 2 had detectable CMV in the stool, resulting in a sensitivity of 28.6%. In the 51 patients without CMV enteritis, 44 had no detectable CMV in the stool, with a specificity of 86.3%. We concluded that CMV detection in the feces was not a good predictor of CMV enteritis in patients with intestinal GVHD after allo-HSCT. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of room temperature transport vials on DNA quality and phylogenetic composition of faecal microbiota of elderly adults and infants.

PubMed

Hill, Cian J; Brown, Jillian R M; Lynch, Denise B; Jeffery, Ian B; Ryan, C Anthony; Ross, R Paul; Stanton, Catherine; O'Toole, Paul W

2016-05-10

Alterations in intestinal microbiota have been correlated with a growing number of diseases. Investigating the faecal microbiota is widely used as a non-invasive and ethically simple proxy for intestinal biopsies. There is an urgent need for collection and transport media that would allow faecal sampling at distance from the processing laboratory, obviating the need for same-day DNA extraction recommended by previous studies of freezing and processing methods for stool. We compared the faecal bacterial DNA quality and apparent phylogenetic composition derived using a commercial kit for stool storage and transport (DNA Genotek OMNIgene GUT) with that of freshly extracted samples, 22 from infants and 20 from older adults. Use of the storage vials increased the quality of extracted bacterial DNA by reduction of DNA shearing. When infant and elderly datasets were examined separately, no differences in microbiota composition were observed due to storage. When the two datasets were combined, there was a difference according to a Wilcoxon test in the relative proportions of Faecalibacterium, Sporobacter, Clostridium XVIII, and Clostridium XlVa after 1 week's storage compared to immediately extracted samples. After 2 weeks' storage, Bacteroides abundance was also significantly different, showing an apparent increase from week 1 to week 2. The microbiota composition of infant samples was more affected than that of elderly samples by storage, with significantly higher Spearman distances between paired freshly extracted and stored samples (p < 0.001). When the microbiota profiles were analysed at the operational taxonomic unit (OTU) level, three infant datasets in the study did not cluster together, while only one elderly dataset did not. The lower microbiota diversity of the infant gut microbiota compared to the elderly gut microbiota (p < 0.001) means that any alteration in the infant datasets has a proportionally larger effect. The commercial storage vials appear

Teaching retirement financial literacy in an undergraduate gerontology classroom: broadening the concept of the tripod or three-legged stool of retirement income utilizing active learning.

PubMed

Baker, Hallie E; Brown, Pamela Pitman

2015-01-01

The three-legged stool concept is widely used in gerontological and geriatric education as an explanation on how one should fiscally approach his or her retirement. Financial managers, planners, retirees, business owners, even the Social Security Administration uses this metaphor of fiscal soundness in retirement planning. Gerontologists are moving away from the "tripod of retirement income" and "three-legged stool" term, as more often market work is needed for financial security. This activity focuses on the tripod or three-legged stool concepts of retirement planning using active learning, allowing the students to work collaboratively in a group, reflect upon the activity, and most importantly have fun. The game also allows for an expansion of the tripod concepts into the four pillars of economic security, broaching the use of personal assets and the possible need for longer employment. Game scenarios also emphasize macro- and microlevel forces, such as race, gender, health status, education, or marital status, which can influence timing of retirement or the level of retirement income available. The authors include instructions on how to set up the learning experience including worksheets, as well as reflection questions posed throughout the process.

Evaluation of sampling and storage procedures on preserving the community structure of stool microbiota: A simple at-home toilet-paper collection method.

PubMed

Al, Kait F; Bisanz, Jordan E; Gloor, Gregory B; Reid, Gregor; Burton, Jeremy P

2018-01-01

The increasing interest on the impact of the gut microbiota on health and disease has resulted in multiple human microbiome-related studies emerging. However, multiple sampling methods are being used, making cross-comparison of results difficult. To avoid additional clinic visits and increase patient recruitment to these studies, there is the potential to utilize at-home stool sampling. The aim of this pilot study was to compare simple self-sampling collection and storage methods. To simulate storage conditions, stool samples from three volunteers were freshly collected, placed on toilet tissue, and stored at four temperatures (-80, 7, 22 and 37°C), either dry or in the presence of a stabilization agent (RNAlater®) for 3 or 7days. Using 16S rRNA gene sequencing by Illumina, the effect of storage variations for each sample was compared to a reference community from fresh, unstored counterparts. Fastq files may be accessed in the NCBI Sequence Read Archive: Bioproject ID PRJNA418287. Microbial diversity and composition were not significantly altered by any storage method. Samples were always separable based on participant, regardless of storage method suggesting there was no need for sample preservation by a stabilization agent. In summary, if immediate sample processing is not feasible, short term storage of unpreserved stool samples on toilet paper offers a reliable way to assess the microbiota composition by 16S rRNA gene sequencing. Copyright © 2017 Elsevier B.V. All rights reserved.

The use of probiotics in healthy volunteers with evacuation disorders and hard stools: a double-blind, randomized, placebo-controlled study.

PubMed

Del Piano, Mario; Carmagnola, Stefania; Anderloni, Andrea; Andorno, Silvano; Ballarè, Marco; Balzarini, Marco; Montino, Franco; Orsello, Marco; Pagliarulo, Michela; Sartori, Massimo; Tari, Roberto; Sforza, Filomena; Capurso, Lucio

2010-09-01

Evacuation disorders and hard stools are common in industrialized countries, affecting on average 12% to 17% of the adult healthy population at any age. Dietary supplementation with probiotic microorganisms may be useful in reducing the disorder. We performed a double-blind, randomized, placebo-controlled study to evaluate the effectiveness of 2 different probiotic blends, either mixed Lactobacillus plantarum LP01 (LMG P-21021) and Bifidobacterium breve BR03 (DSM 16604) or Bifidobacterium animalis subspecies lactis BS01 (LMG P-21384), in the management of evacuation disorders and intestinal discomfort. In a period of 5 years (2003 to 2008), the study involved 300 healthy volunteers (151 males and 149 females; age 24 to 71 y) with evacuation disorders and hard stools. In particular, subjects were divided into 3 groups: 80 subjects in the group A received placebo, 110 subjects in the group B received mixed L. plantarum LP01 and B. breve BR03 (2.5 x 10 colony-forming units/d of each strain), and 110 subjects in the group C received B. animalis subsp. lactis BS01 (5 x 10 colony-forming units/d) for 30 days. At the beginning of the observational study, the healthy status of volunteers was evaluated by a complete, laboratory and ultrasound study of the abdomen. The physical examination was repeated after 15 and 30 days. In particular, the main troubles typically associated with evacuation disorders and hard stools as well as abdominal bloating were considered as parameters of interest. Exclusion criteria were items of gastrointestinal diseases and antibiotics intake. Subjects treated with the mixed probiotic strains L. plantarum LP01 and B. breve BR03 or B. animalis subsp. lactis BS01 reported a significant improvement in the number of weekly bowel movements and in the main troubles associated with evacuations, particularly consistency of feces and ease of expulsion. Discomfort items such as abdominal bloating and anal itching, burning, or pain also registered a relevant

Metal complexes as DNA intercalators.

PubMed

Liu, Hong-Ke; Sadler, Peter J

2011-05-17

DNA has a strong affinity for many heterocyclic aromatic dyes, such as acridine and its derivatives. Lerman in 1961 first proposed intercalation as the source of this affinity, and this mode of DNA binding has since attracted considerable research scrutiny. Organic intercalators can inhibit nucleic acid synthesis in vivo, and they are now common anticancer drugs in clinical therapy. The covalent attachment of organic intercalators to transition metal coordination complexes, yielding metallointercalators, can lead to novel DNA interactions that influence biological activity. Metal complexes with σ-bonded aromatic side arms can act as dual-function complexes: they bind to DNA both by metal coordination and through intercalation of the attached aromatic ligand. These aromatic side arms introduce new modes of DNA binding, involving mutual interactions of functional groups held in close proximity. The biological activity of both cis- and trans-diamine Pt(II) complexes is dramatically enhanced by the addition of σ-bonded intercalators. We have explored a new class of organometallic "piano-stool" Ru(II) and Os(II) arene anticancer complexes of the type [(η(6)-arene)Ru/Os(XY)Cl](+). Here XY is, for example, ethylenediamine (en), and the arene ligand can take many forms, including tetrahydroanthracene, biphenyl, or p-cymene. Arene-nucleobase stacking interactions can have a significant influence on both the kinetics and thermodynamics of DNA binding. In particular, the cytotoxic activity, conformational distortions, recognition by DNA-binding proteins, and repair mechanisms are dependent on the arene. A major difficulty in developing anticancer drugs is cross-resistance, a phenomenon whereby a cell that is resistant to one drug is also resistant to another drug in the same class. These new complexes are non-cross-resistant with cisplatin towards cancer cells: they constitute a new class of anticancer agents, with a mechanism of action that differs from the anticancer

Real-time RT-PCR assays to differentiate wild-type group A rotavirus strains from Rotarix(®) and RotaTeq(®) vaccine strains in stool samples.

PubMed

Gautam, Rashi; Esona, Mathew D; Mijatovic-Rustempasic, Slavica; Ian Tam, Ka; Gentsch, Jon R; Bowen, Michael D

2014-01-01

Group A rotaviruses (RVA) are the leading cause of severe diarrhea in young children worldwide. Two live-attenuated RVA vaccines, Rotarix(®) and RotaTeq(®) are recommended by World Health Organization (WHO) for routine immunization of all infants. Rotarix(®) and RotaTeq(®) vaccines have substantially reduced RVA associated mortality but occasionally have been associated with acute gastroenteritis (AGE) cases identified in vaccinees and their contacts. High-throughput assays are needed to monitor the prevalence of vaccine strains in AGE cases and emergence of new vaccine-derived strains following RVA vaccine introduction. In this study, we have developed quantitative real-time RT-PCR (qRT-PCR) assays for detection of Rotarix(®) and RotaTeq(®) vaccine components in stool samples. Real-time RT-PCR assays were designed for vaccine specific targets in the genomes of Rotarix(®) (NSP2, VP4) and RotaTeq(®) (VP6, VP3-WC3, VP3-human) and validated on sequence confirmed stool samples containing vaccine strains, wild-type RVA strains, and RVA-negative stools. For quantification, standard curves were generated using dsRNA transcripts derived from RVA gene segments. Rotarix(®) NSP2 and VP4 qRT-PCR assays exhibited 92-100% sensitivity, 99-100% specificity, 94-105% efficiency, and a limit of detection of 2-3 copies per reaction. RotaTeq(®) VP6, VP3-WC3, and VP3-human qRT-PCR assays displayed 100% sensitivity, 94-100% specificity, 91-102% efficiency and limits of detection of 1 copy, 2 copies, and 140 copies, respectively. These assays permit rapid identification of Rotarix(®) and RotaTeq(®) vaccine components in stool samples from clinical and surveillance studies and will be helpful in determining the frequency of vaccine strain-associated AGE.

Real-time RT-PCR assays to differentiate wild-type group A rotavirus strains from Rotarix® and RotaTeq® vaccine strains in stool samples

PubMed Central

Gautam, Rashi; Esona, Mathew D; Mijatovic-Rustempasic, Slavica; Ian Tam, Ka; Gentsch, Jon R; Bowen, Michael D

2014-01-01

Group A rotaviruses (RVA) are the leading cause of severe diarrhea in young children worldwide. Two live-attenuated RVA vaccines, Rotarix® and RotaTeq® are recommended by World Health Organization (WHO) for routine immunization of all infants. Rotarix® and RotaTeq® vaccines have substantially reduced RVA associated mortality but occasionally have been associated with acute gastroenteritis (AGE) cases identified in vaccinees and their contacts. High-throughput assays are needed to monitor the prevalence of vaccine strains in AGE cases and emergence of new vaccine-derived strains following RVA vaccine introduction. In this study, we have developed quantitative real-time RT-PCR (qRT-PCR) assays for detection of Rotarix® and RotaTeq® vaccine components in stool samples. Real-time RT-PCR assays were designed for vaccine specific targets in the genomes of Rotarix® (NSP2, VP4) and RotaTeq® (VP6, VP3-WC3, VP3-human) and validated on sequence confirmed stool samples containing vaccine strains, wild-type RVA strains, and RVA-negative stools. For quantification, standard curves were generated using dsRNA transcripts derived from RVA gene segments. Rotarix® NSP2 and VP4 qRT-PCR assays exhibited 92–100% sensitivity, 99–100% specificity, 94–105% efficiency, and a limit of detection of 2–3 copies per reaction. RotaTeq® VP6, VP3-WC3, and VP3-human qRT-PCR assays displayed 100% sensitivity, 94–100% specificity, 91–102% efficiency and limits of detection of 1 copy, 2 copies, and 140 copies, respectively. These assays permit rapid identification of Rotarix® and RotaTeq® vaccine components in stool samples from clinical and surveillance studies and will be helpful in determining the frequency of vaccine strain-associated AGE. PMID:24342877

Home-based screening for biliary atresia using infant stool colour cards: a large-scale prospective cohort study and cost-effectiveness analysis.

PubMed

Schreiber, Richard A; Masucci, Lisa; Kaczorowski, Janusz; Collet, J P; Lutley, Pamela; Espinosa, Victor; Bryan, Stirling

2014-09-01

Biliary atresia (BA), a leading cause of paediatric liver failure and liver transplantation, manifests by three weeks of life as jaundice with acholic stools. Poor outcomes due to delayed diagnosis remain a problem worldwide. We evaluated and assessed the cost-effectiveness of methods of introducing a BA Infant Stool Colour Card (ISCC) screening programme in Canada. A prospective study at BC Women's Hospital recruited consecutive healthy newborns through six incrementally more intensive screening approaches. Under the baseline "passive" strategy, families received ISCCs at maternity, with instructions to monitor infant stool colour daily and return the ISCC by mail at age 30 days. Additional strategies were: ISCC mailed to family physician; reminder letters or telephone calls to families or physicians. Random telephone surveys of ISCC non-returners assessed total card utilization. Primary outcome was ISCC utilization rate expressed as a composite outcome of the ISCC return rate and non-returned ISCC use. Markov modelling was used to predict incremental costs and life years gained from screening (passive and reminder), compared with no screening, over a 10-year time horizon. 6,187 families were enrolled. Card utilization rates in the passive screening strategy were estimated at 60-94%. For a Canadian population, the increase in cost for passive screening, compared with no screening, is $213,584 and the gain in life years is 9.7 ($22,000 per life-year gained). A BA ISCC screening programme targeting families of newborns is feasible in Canada. Passive distribution of ISCC at maternity is potentially effective and highly cost-effective. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

[Detection of stool antigens of Echinococcus granulosus in dogs belonging to slaughterhouse workers and offal merchants in Metropolitan Lima].

PubMed

Merino, Veronika; Falcón, Néstor; Morel, Noelia; González, Gualberto

2017-04-20

To demonstrate the presence of Echinoccocus granulosus in the definitive host in the city of Lima, Perú, by detecting parasite antigens in the stool of dogs belonging to offal handlers and merchants in authorized slaughterhouses in Metropolitan Lima. Stool samples were collected from 58 dogs and examined using the coproELISA technique for the detection of secretory/excretory antigens of E. granulosus. A survey was conducted to obtain information on pet feeding and handling practices. Positivity to E. granulosus was detected in 13.8% (8/58) of the dogs. In 27.8% (5/18) of the homes, at least one animal showed positivity, and in families that had more than four dogs the chances of finding positivity in at least one dog were higher (P < 0.05). In all homes where at least one dog tested positive the pets were fed on offal. Of study participants, 94.4% (17) knew nothing about the routes of transmission of hydatid disease. Results show the presence of definitive hosts in the urban area of Lima and underscore the need to more widely disseminate practices for the prevention of parasite transmission.

Clinical and Analytical Evaluation of a Single-Vial Stool Collection Device with Formalin-Free Fixative for Improved Processing and Comprehensive Detection of Gastrointestinal Parasites.

PubMed

Couturier, Brianne A; Jensen, Ryan; Arias, Nora; Heffron, Michael; Gubler, Elyse; Case, Kristin; Gowans, Jason; Couturier, Marc Roger

2015-08-01

Microscopic examination of feces is a standard laboratory method for diagnosing gastrointestinal parasite infections. In North America, the ovum and parasite (O&P) examination is typically performed using stool that is chemically fixed in polyvinyl alcohol (PVA) and formalin, after which the stool is concentrated by filtration to enhance sensitivity. Mini Parasep solvent-free (SF) tubes allow collection and concentration within a single collection vial. The goal of the study was to determine whether consolidated processing and concentration with the Parasep tubes using an alcohol-based fixative (Alcorfix) provide O&P examinations equivalent to or better than those done by processing of PVA-formalin-fixed stool using a SpinCon concentration device. Parasep tubes revealed filtration performance equivalent to that of the SpinCon concentration device using PVA-formalin-fixed stool containing protozoa. Specimens cocollected in Parasep tubes containing PVA-formalin and Alcorfix revealed comparable morphology and staining for various protozoa. Alcorfix effectively fixed live Cryptosporidium and microsporidia such that morphology and staining were conserved for modified acid-fast and modified trichrome stains. A work flow analysis revealed significant time savings for batches of 10 or 30 O&P specimens in tubes with Alcorfix compared to the amount of time that it took to analyze the same number of specimens in tubes with PVA-formalin. The direct hands-on time savings with Mini Parasep tubes were 17 min and 41 s and 32 min and 1 s for batches of 10 and 30 specimens, respectively. Parasep tubes containing Alcorfix provide significant work flow advantages to laboratories that process medium to high volumes of O&P specimens by streamlining processing and converting to a single tube. These improvements in work flow, reduction of the amount of formalin used in the laboratory, and equivalent microscopy results are attractive advancements in O&P testing for North American

Colon cancer screening

MedlinePlus

Screening for colon cancer; Colonoscopy - screening; Sigmoidoscopy - screening; Virtual colonoscopy - screening; Fecal immunochemical test; Stool DNA test; sDNA test; Colorectal cancer - screening; Rectal ...

Repeat Rifaximin for Irritable Bowel Syndrome: No Clinically Significant Changes in Stool Microbial Antibiotic Sensitivity.

PubMed

Pimentel, M; Cash, B D; Lembo, A; Wolf, R A; Israel, R J; Schoenfeld, P

2017-09-01

Rifaximin has demonstrated efficacy and safety for diarrhea-predominant irritable bowel syndrome (IBS-D). To determine the rifaximin repeat treatment effect on fecal bacterial antibiotic susceptibility. Patients with IBS in Trial 3 (TARGET 3) study who responded to open-label rifaximin 550 mg three times daily for 2 weeks, with symptom recurrence within 18 weeks, were randomized to double-blind treatment: two 2-week repeat courses of rifaximin or placebo, separated by 10 weeks. Prospective stool sample collection occurred before and after open-label rifaximin, before and after the first repeat course, and at the end of the study. Susceptibility testing was performed with 11 antibiotics, including rifaximin and rifampin, using broth microdilution or agar dilution methods. Of 103 patients receiving open-label rifaximin, 73 received double-blind rifaximin (n = 37) or placebo (n = 36). A total of 1429 bacterial and yeast isolates were identified, of which Bacteroidaceae (36.7%) and Enterobacteriaceae (33.9%) were the most common. In the double-blind phase, Clostridium difficile was highly susceptible to rifaximin [minimum inhibitory concentration (MIC) range 0.008-1 µg/mL] and rifampin (MIC range 0.004-0.25 µg/mL). Following double-blind rifaximin treatment, Staphylococcus isolates remained susceptible to rifaximin at all visits (MIC 50 range ≤0.06-32 µg/mL). Rifaximin exposure was not associated with long-term cross-resistance of Bacteroidaceae, Enterobacteriaceae, and Enterococcaceae to rifampin or nonrifamycin antibiotics tested. In this study, short-term repeat treatment with rifaximin has no apparent long-term effect on stool microbial susceptibility to rifaximin, rifampin, and nonrifamycin antibiotics. CLINICALTRIALS. NCT01543178.

Variation in the limit-of-detection of the ProSpecT Campylobacter microplate enzyme immunoassay in stools spiked with emerging Campylobacter species.

PubMed

Bojanić, Krunoslav; Midwinter, Anne Camilla; Marshall, Jonathan Craig; Rogers, Lynn Elizabeth; Biggs, Patrick Jon; Acke, Els

2016-08-01

Campylobacter enteritis in humans is primarily associated with C. jejuni/coli infection. The impact of other Campylobacter spp. is likely to be underestimated due to the bias of culture methods towards Campylobacter jejuni/coli diagnosis. Stool antigen tests are becoming increasingly popular and appear generally less species-specific. A review of independent studies of the ProSpecT® Campylobacter Microplate enzyme immunoassay (EIA) developed for C. jejuni/coli showed comparable diagnostic results to culture methods but the examination of non-jejuni/coli Campylobacter spp. was limited and the limit-of-detection (LOD), where reported, varied between studies. This study investigated LOD of EIA for Campylobacter upsaliensis, Campylobacter hyointestinalis and Campylobacter helveticus spiked in human stools. Multiple stools and Campylobacter isolates were used in three different concentrations (10(4)-10(9)CFU/ml) to reflect sample heterogeneity. All Campylobacter species evaluated were detectable by EIA. Multivariate analysis showed LOD varied between Campylobacter spp. and faecal consistency as fixed effects and individual faecal samples as random effects. EIA showed excellent performance in replicate testing for both within and between batches of reagents, in agreement between visual and spectrophotometric reading of results, and returned no discordance between the bacterial concentrations within independent dilution test runs (positive results with lower but not higher concentrations). This study shows how limitations in experimental procedures lead to an overestimation of consistency and uniformity of LOD for EIA that may not hold under routine use in diagnostic laboratories. Benefits and limitations for clinical practice and the influence on estimates of performance characteristics from detection of multiple Campylobacter spp. by EIA are discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

Standardization of a latex agglutination test for coproantigen detection of Fasciola sp. in bovine cattle stool.

PubMed

Orejarena Ávila, Lina Paola; Inguilan Benavides, Erika Marcela; Padilla Sanabria, Leonardo; Recalde-Reyes, Delia Piedad; Rodríguez-Salazar, Carlos Andrés; Castaño-Osorio, Jhon Carlos

2018-03-01

Fasciolosis is a zoonotic parasitic disease, which affects humans and animals; diagnosed through noncommercial immunoassay tests that cannot be used on the field. Thereby, establishing the optimal conditions to develop a latex agglutination technique with IgG and IgM antibodies directed against excretion/secretion antigens of Fasciola sp. is a priority. Latex particles were sensitized with IgG and IgM antibodies directed against excretion/secretion antigens of Fasciola sp. The specificity of the antibodies was determined against antigens of different helminths and protozoa; the sensitivity and specificity of the test was evaluated against a previously standardized direct ELISA. The coupling rates of the IgG and IgM antibodies were 85.77 and 100%, respectively. The minimum detectable concentration of Fasciola sp. excretion/secretion antigens, diluted in a phosphate-buffered saline, was 1.589 mg/mL(IgG) and 0.158 mg/mL(IgM) and for the antigens incorporated in the bovine cattle stool it was 3.178 mg/mL(IgG) and 1.589 mg/mL(IgM). The test showed crossed reaction against Giardia sp., and Cryptosporidium sp. antigens. Agreement of the IgG and IgM latex test against the ELISA test was of 78.78 and 96.96%, respectively; the specificity found was of 100% for both tests and sensitivity was 78.79% (IgG) and 96.97% (IgM). This work standardized the latex agglutination technique to detect Fasciola sp. antigens in bovine cattle stool.

Recombinase Polymerase Amplification Compared to Real-Time Polymerase Chain Reaction Test for the Detection of Fasciola hepatica in Human Stool

PubMed Central

Cabada, Miguel M.; Malaga, Jose L.; Castellanos-Gonzalez, Alejandro; Bagwell, Kelli A.; Naeger, Patrick A.; Rogers, Hayley K.; Maharsi, Safa; Mbaka, Maryann; White, A. Clinton

2017-01-01

Fasciola hepatica is the most widely distributed trematode infection in the world. Control efforts may be hindered by the lack of diagnostic capacity especially in remote endemic areas. Polymerase chain reaction (PCR)–based methods offer high sensitivity and specificity but require expensive technology. However, the recombinase polymerase amplification (RPA) is an efficient isothermal method that eliminates the need for a thermal cycler and has a high deployment potential to resource-limited settings. We report on the characterization of RPA and PCR tests to detect Fasciola infection in clinical stool samples with low egg burdens. The sensitivity of the RPA and PCR were 87% and 66%, respectively. Both tests were 100% specific showing no cross-reactivity with trematode, cestode, or nematode parasites. In addition, RPA and PCR were able to detect 47% and 26% of infections not detected by microscopy, respectively. The RPA adapted to a lateral flow platform was more sensitive than gel-based detection of the reaction products. In conclusion, the Fasciola RPA is a highly sensitive and specific test to diagnose chronic infection using stool samples. The Fasciola RPA lateral flow has the potential for deployment to endemic areas after further characterization. PMID:27821691

Comparison of Various Methods in the Diagnosis of Entamoeba histolytica in Stool and Serum Specimens

PubMed Central

Uslu, Hakan; Aktas, Osman; Uyanik, Muhammet Hamidullah

2016-01-01

Objective: Entamoeba histolytica is indistinguishable from Entamoeba dispar in direct microscopic examination. A definitive diagnosis of E. histolytica is important in terms of the treatment of the patient and to avoid unnecessary costs. This study’s aim is to determine the prevalence of E. histolytica and to make a comparison of the different diagnostic tests in the patients specimens defined as E. histolytica/E. dispar infection. Materials and Methods: Faecal and serum specimens of 90 patients defined as E. histolytica/E. dispar with microscopy (wet mount examination with 0.85% saline and Lugol’s iodine) were examined. Stool samples were examined by trichrome staining for trophozoites and cysts and by immunoassay methods for specific adhesin antigens (Wampole ® E. histolytica II antigen testing) and for specific serine-rich 30 kD membrane protein (Serazym® E. histolytica antigen testing). Anti-E. histolytica antibodies were investigated using a latex slide test and indirect hemagglutination methods in serum specimens. Results: Presence of E. histolytica was not confirmed in 31.1% cases with trichrome staining, 62.2% of the Wampole antigen test, 64.4%, of the Serazym antigen test, 73.3% of the indirect hemagglutination test and 75.6%. of the latex agglutination. Considering the common results from Wampole and Serazym antigen testing as a reference standard, the specificity/sensitivity is 100/53.85% for trichrome staining, 75.00/98.11% for the latex agglutination test and 78.57/96.77% for the indirect hemagglutination test. Conclusion: It has been shown that investigation of E. histolytica in stools by direct wet-smear microscopy alone can cause significant false positive results. To obtain a reliable diagnosis for E. histolytica and to avoid unnecessary treatment for this parasite, at least one more specific assay, particularly an antigen testing and microscopy, is required. PMID:27551176

Evaluation of RIDA®GENE norovirus GI/GII real time RT-PCR using stool specimens collected from children and adults with acute gastroenteritis.

PubMed

Kanwar, N; Hassan, F; Barclay, L; Langley, C; Vinjé, J; Bryant, P W; George, K St; Mosher, L; Matthews-Greer, J M; Rocha, M A; Beenhouwer, D O; Harrison, C J; Moffatt, M; Shastri, N; Selvarangan, R

2018-04-10

Norovirus is the leading cause of epidemic and sporadic acute gastroenteritis (AGE) in the United States. Widespread prevalence necessitates implementation of accurate norovirus detection assays in clinical diagnostic laboratories. To evaluate RIDA ® GENE norovirus GI/GII real-time RT-PCR assay (RGN RT-PCR) using stool samples from patients with sporadic AGE. Patients between 14 days to 101 years of age with symptoms of AGE were enrolled prospectively at four sites across the United States during 2014-2015. Stool specimens were screened for the presence of norovirus RNA by the RGN RT-PCR assay. Results were compared with a reference method that included conventional RT-PCR and sequencing of a partial region of the 5'end of the norovirus ORF2 gene. A total of 259 (36.0%) of 719 specimens tested positive for norovirus by the reference method. The RGN RT-PCR assay detected norovirus in 244 (94%) of these 259 norovirus positive specimens. The sensitivity and specificity (95% confidence interval) of the RGN RT-PCR assay for detecting norovirus genogroup (G) I was 82.8% (63.5-93.5) and 99.1% (98.0-99.6) and for GII was 94.8% (90.8-97.2) and 98.6% (96.9-99.4), respectively. Seven specimens tested positive by the RGN-RT PCR that were negative by the reference method. The fifteen false negative samples were typed as GII.4 Sydney, GII.13, GI.3, GI.5, GI.2, GII.1, and GII.3 in the reference method. The RGN RT-PCR assay had a high sensitivity and specificity for the detection of norovirus in stool specimens from patients with sporadic AGE. Copyright © 2018. Published by Elsevier B.V.

The use of a gas chromatograph coupled to a metal oxide sensor for rapid assessment of stool samples from irritable bowel syndrome and inflammatory bowel disease patients

PubMed Central

Shepherd, S F; McGuire, N D; de Lacy Costello, B P J; Ewen, R J; Jayasena, D H; Vaughan, K; Ahmed, I; Probert, C S; Ratcliffe, N M

2016-01-01

There is much clinical interest in the development of a low cost and reliable test for diagnosing inflammatory bowel disease and irritable bowel syndrome, two very distinct diseases that can present with similar symptoms. The assessment of stool samples for the diagnosis of gastro-intestinal diseases is in principle an ideal non-invasive testing method. This paper presents an approach to stool analysis using headspace gas chromatography and a single metal oxide sensor coupled to artificial neural network (ANN) software. Currently the system is able to distinguish samples from patients with irritable bowel syndrome (IBS) from patients with inflammatory bowel disease (IBD) with a sensitivity and specificity of 76% and 88% respectively, with an overall mean predictive accuracy of 76%. PMID:24674940

Identification and characterization of unrecognized viruses in stool samples of non-polio acute flaccid paralysis children by simplified VIDISCA.

PubMed

Shaukat, Shahzad; Angez, Mehar; Alam, Muhammad Masroor; Jebbink, Maarten F; Deijs, Martin; Canuti, Marta; Sharif, Salmaan; de Vries, Michel; Khurshid, Adnan; Mahmood, Tariq; van der Hoek, Lia; Zaidi, Syed Sohail Zahoor

2014-08-12

The use of sequence independent methods combined with next generation sequencing for identification purposes in clinical samples appears promising and exciting results have been achieved to understand unexplained infections. One sequence independent method, Virus Discovery based on cDNA Amplified Fragment Length Polymorphism (VIDISCA) is capable of identifying viruses that would have remained unidentified in standard diagnostics or cell cultures. VIDISCA is normally combined with next generation sequencing, however, we set up a simplified VIDISCA which can be used in case next generation sequencing is not possible. Stool samples of 10 patients with unexplained acute flaccid paralysis showing cytopathic effect in rhabdomyosarcoma cells and/or mouse cells were used to test the efficiency of this method. To further characterize the viruses, VIDISCA-positive samples were amplified and sequenced with gene specific primers. Simplified VIDISCA detected seven viruses (70%) and the proportion of eukaryotic viral sequences from each sample ranged from 8.3 to 45.8%. Human enterovirus EV-B97, EV-B100, echovirus-9 and echovirus-21, human parechovirus type-3, human astrovirus probably a type-3/5 recombinant, and tetnovirus-1 were identified. Phylogenetic analysis based on the VP1 region demonstrated that the human enteroviruses are more divergent isolates circulating in the community. Our data support that a simplified VIDISCA protocol can efficiently identify unrecognized viruses grown in cell culture with low cost, limited time without need of advanced technical expertise. Also complex data interpretation is avoided thus the method can be used as a powerful diagnostic tool in limited resources. Redesigning the routine diagnostics might lead to additional detection of previously undiagnosed viruses in clinical samples of patients.

Evaluation of a multiplex PCR assay for detection of cytomegalovirus in stool samples from patients with ulcerative colitis

PubMed Central

Nahar, Saifun; Iraha, Atsushi; Hokama, Akira; Uehara, Ayako; Parrott, Gretchen; Ohira, Tetsuya; Kaida, Masatoshi; Kinjo, Tetsu; Kinjo, Takeshi; Hirata, Tetsuo; Kinjo, Nagisa; Fujita, Jiro

2015-01-01

AIM: To evaluate a multiplex PCR assay for the detection of bacterial and viral enteropathogens in stool samples from patients with ulcerative colitis (UC). METHODS: We prospectively analyzed 300 individuals, including immunocompetent patients, immunocompromised patients, and patients with UC. Stool samples were collected from the recto-sigmoid region of the colon by endoscopy. The samples were qualitatively analyzed for bacterial and viral enteropathogens with a multiplex PCR assay using a Seeplex® Kit. Additional clinical and laboratory data were collected from the medical records. RESULTS: A multiplex PCR assay detected 397 pathogens (191 bacteria and 206 viruses) in 215 samples (71.7%). The most frequently detected bacteria were Escherichia coli H7, 85 (28.3%); followed by Aeromonas spp., 43 (14.3%); and Clostridium perfringens, 36 (12.0%) samples. The most prevalent viruses were Epstein-Barr virus (EBV), 90 (30.0%); followed by human herpes virus-6 (HHV-6), 53 (17.7%); and cytomegalovirus (CMV), 37 (12.3%) samples. The prevalence rate of CMV infection was significantly higher in the immunocompromised group than in the immunocompetent group (P < 0.01). CMV infection was more common in patients with UC (26/71; 36.6%) than in the immunocompetent patients excluding UC (6/188; 3.2%) (P < 0.01). CMV infection was more prevalent in UC active patients (25/58; 43.1%) than in UC inactive patients (1/13; 7.7%) (P < 0.05). Among 4 groups which defined by the UC activity and immunosuppressive drugs, the prevalence rate of CMV infection was highest in the UC active patients with immunosuppressive drugs (19/34; 55.8%). Epstein-Barr virus (EBV) infection was more common in the immunocompromised patients excluding UC (18/41; 43.9%) than in the immunocompetent patients excluding UC (47/188; 25.0%) (P < 0.05). The simultaneous presence of CMV and EBV and/or HHV6 in UC active patients (14/58; 24.1%) was greater than in immunocompromised patients excluding UC (5/41; 12.2%) (P < 0

Long-term frozen storage of urine samples: a trouble to get PCR results in Schistosoma spp. DNA detection?

PubMed

Fernández-Soto, Pedro; Velasco Tirado, Virginia; Carranza Rodríguez, Cristina; Pérez-Arellano, José Luis; Muro, Antonio

2013-01-01

Human schistosomiasis remains a serious worldwide public health problem. At present, a sensitive and specific assay for routine diagnosis of schistosome infection is not yet available. The potential for detecting schistosome-derived DNA by PCR-based methods in human clinical samples is currently being investigated as a diagnostic tool with potential application in routine schistosomiasis diagnosis. Collection of diagnostic samples such as stool or blood is usually difficult in some populations. However, urine is a biological sample that can be collected in a non-invasive method, easy to get from people of all ages and easy in management, but as a sample for PCR diagnosis is still not widely used. This could be due to the high variability in the reported efficiency of detection as a result of the high variation in urine samples' storage or conditions for handling and DNA preservation and extraction methods. We evaluate different commercial DNA extraction methods from a series of long-term frozen storage human urine samples from patients with parasitological confirmed schistosomiasis in order to assess the PCR effectiveness for Schistosoma spp. detection. Patients urine samples were frozen for 18 months up to 7 years until use. Results were compared with those obtained in PCR assays using fresh healthy human urine artificially contaminated with Schistosoma mansoni DNA and urine samples from mice experimentally infected with S. mansoni cercariae stored frozen for at least 12 months before use. PCR results in fresh human artificial urine samples using different DNA based extraction methods were much more effective than those obtained when long-term frozen human urine samples were used as the source of DNA template. Long-term frozen human urine samples are probably not a good source for DNA extraction for use as a template in PCR detection of Schistosoma spp., regardless of the DNA method of extraction used.

sTools - a data reduction pipeline for the GREGOR Fabry-Pérot Interferometer and the High-resolution Fast Imager at the GREGOR solar telescope

NASA Astrophysics Data System (ADS)

Kuckein, C.; Denker, C.; Verma, M.; Balthasar, H.; González Manrique, S. J.; Louis, R. E.; Diercke, A.

2017-10-01

A huge amount of data has been acquired with the GREGOR Fabry-Pérot Interferometer (GFPI), large-format facility cameras, and since 2016 with the High-resolution Fast Imager (HiFI). These data are processed in standardized procedures with the aim of providing science-ready data for the solar physics community. For this purpose, we have developed a user-friendly data reduction pipeline called ``sTools'' based on the Interactive Data Language (IDL) and licensed under creative commons license. The pipeline delivers reduced and image-reconstructed data with a minimum of user interaction. Furthermore, quick-look data are generated as well as a webpage with an overview of the observations and their statistics. All the processed data are stored online at the GREGOR GFPI and HiFI data archive of the Leibniz Institute for Astrophysics Potsdam (AIP). The principles of the pipeline are presented together with selected high-resolution spectral scans and images processed with sTools.

Identification of Ixodes ricinus blood meals using an automated protocol with high resolution melting analysis (HRMA) reveals the importance of domestic dogs as larval tick hosts in Italian alpine forests.

PubMed

Collini, Margherita; Albonico, Francesca; Rosà, Roberto; Tagliapietra, Valentina; Arnoldi, Daniele; Conterno, Lorenza; Rossi, Chiara; Mortarino, Michele; Rizzoli, Annapaola; Hauffe, Heidi Christine

2016-12-12

In Europe, Ixodes ricinus L. is the main vector of a variety of zoonotic pathogens, acquired through blood meals taken once per stage from a vertebrate host. Defining the main tick hosts in a given area is important for planning public health interventions; however, until recently, no robust molecular methods existed for blood meal identification from questing ticks. Here we improved the time- and cost-effectiveness of an HRMA protocol for blood meal analysis and used it to identify blood meal sources of sheep tick larvae from Italian alpine forests. Nine hundred questing nymphs were collected using blanket-dragging in 18 extensive forests and 12 forest patches close to rural villages in the Province of Trento. Total DNA was either extracted manually, with the QIAamp DNA Investigator kit, or automatically using the KingFisher™ Flex Magnetic Particle Processors (KingFisher Cell and Tissue DNA Kit). Host DNA was amplified with six independent host group real-time PCR reactions and identified by means of HRMA. Statistical analyses were performed in R to assess the variables important for achieving successful identification and to compare host use in the two types of forest. Automating DNA extraction improved time- and cost-effectiveness of the HRMA protocol, but identification success fell to 22.4% (KingFisher™) from 55.1% (QIAamp), with larval hosts identified in 215 of 848 questing nymphs; 23 mixed blood meals were noted. However, the list of hosts targeted by our primer sets was extended, improving the potential of the method. Host identification to species or genus level was possible for 137 and 102 blood meals, respectively. The most common hosts were Rodentia (28.9%) and, unexpectedly, Carnivora (28.4%), with domestic dogs accounting for 21.3% of all larval blood meals. Overall, Cetartiodactyla species fed 17.2% of larvae. Passeriformes (14.6%) fed a significantly higher proportion of larvae in forest patches (22.3%) than in extensive forest (9.6%), while

Comparison of 2 chromogenic media for the detection of extended-spectrum β-lactamase producing Enterobacteriaceae stool carriage in nursing home residents.

PubMed

Blane, Beth; Brodrick, Hayley J; Gouliouris, Theodore; Ambridge, Kirsty E; Kidney, Angela D; Ludden, Catherine M; Limmathurotsakul, Direk; Török, M Estée; Peacock, Sharon J

2016-03-01

ChromID ESBL agar and Brilliance ESBL agar were compared for the isolation of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae from 298 stools. These had comparable sensitivity and selectivity for the 116 positive samples. Pre-enrichment with cefpodoxime and extending incubation to 48 hours after direct plating both significantly increased sensitivity but reduced selectivity of both agars. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

A robust ambient temperature collection and stabilization strategy: Enabling worldwide functional studies of the human microbiome

PubMed Central

Anderson, Ericka L.; Li, Weizhong; Klitgord, Niels; Highlander, Sarah K.; Dayrit, Mark; Seguritan, Victor; Yooseph, Shibu; Biggs, William; Venter, J. Craig; Nelson, Karen E.; Jones, Marcus B.

2016-01-01

As reports on possible associations between microbes and the host increase in number, more meaningful interpretations of this information require an ability to compare data sets across studies. This is dependent upon standardization of workflows to ensure comparability both within and between studies. Here we propose the standard use of an alternate collection and stabilization method that would facilitate such comparisons. The DNA Genotek OMNIgene∙Gut Stool Microbiome Kit was compared to the currently accepted community standard of freezing to store human stool samples prior to whole genome sequencing (WGS) for microbiome studies. This stabilization and collection device allows for ambient temperature storage, automation, and ease of shipping/transfer of samples. The device permitted the same data reproducibility as with frozen samples, and yielded higher recovery of nucleic acids. Collection and stabilization of stool microbiome samples with the DNA Genotek collection device, combined with our extraction and WGS, provides a robust, reproducible workflow that enables standardized global collection, storage, and analysis of stool for microbiome studies. PMID:27558918

Detection of enteropathogens associated with travelers’ diarrhea using a multiplex Luminex-based assay performed on stool samples smeared on Whatman FTA Elute cards

PubMed Central

Lalani, Tahaniyat; Tisdale, Michele D; Maguire, Jason D; Wongsrichanalai, Chansuda; Riddle, Mark S; Tribble, David R

2015-01-01

We evaluated the limits of detection (LoD) for an 11-plex PCR-Luminex assay performed on Whatman FTA Elute cards smeared with stool containing pathogens associated with travelers’ diarrhea. LoDs ranged between 102-105 CFU, PFU or cysts/g for most pathogens except Cryptosporidium. Campylobacter and norovirus LoD increased with prolonged storage of cards. PMID:26072151

Lack of KIs virus DNA in plasma and cerebrospinal fluid in Italy.

PubMed

Macera, Lisa; Focosi, Daniele; Manzin, Aldo; Ceccherini Nelli, Luca; Pistello, Mauro; Maggi, Fabrizio

2015-10-01

Dear Sirs, Satoh et al. recently screened 516 Japanese blood donors with PCR using primers constructed from the consensus domain of the helicase of positive-stranded RNA viruses. They reported a novel enveloped virus with a circular double-stranded DNA genome (tentatively named KIs virus, KIs-V) (Satoh et al., 2011) occurring in 36 out of the 100 hepatitis E (HEV) antibody-positive donors with elevated alanine aminotransferase (ALT) levels (>60 IU/L). More recently, Biagini et al. failed to find KIs-V in plasma from 576 French blood donors with unknown HEV serostatus and unknown ALT values (Biagini et al., 2012). Based on an HEV seroprevalence of 3-52% in France, the authors suggested an uncommon frequency of KIs-V infection in healthy persons in France. To date, no information has been available on the prevalence of KIs-V DNA in Italy. In the present paper, we analyzed KIs-V in 242 plasma samples of blood donors, transplant recipients, and patients with chronic viral infections, and in 52 cerebrospinal fluid (CSF) samples of patients with different neurological disorders. Informed consent was obtained from all patients and the study was performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its amendments. Viral DNA extraction was carried out on 200 μl of plasma or 200 μl of CSF by using QIAamp DNA blood kit (Qiagen, Hilden, Germany) according to the manufacturer's instructions. Extracted nucleic acids were amplified for KIs-V DNA with the nested PCR protocol developed by Satoh et al. (2011) and used for screening Japanese blood donors. The first and second PCR rounds were designed on 458 and 304 nt-length fragments, respectively. To validate the amplification process, positive controls obtained from plasma dilutions of a synthetic template corresponding to the target sequence were run in each PCR. PCR sensitivity was less than 5 copies of target sequence. Fourteen liver and 16 kidney and/or pancreas transplant

Contrast enema as a guide for senna-based laxatives in managing overflow retentive stool incontinence in pediatrics.

PubMed

Radwan, Ahmed Bassiuony; El-Debeiky, Mohammed Soliman; Abdel-Hay, Sameh

2015-08-01

Overflow retentive stool incontinence (ORSI) is secondary to constipation and fecal loading. In our study, the dose and duration of senna-based laxatives (SBL) treatment to achieve full defecatory control will be examined for possible correlation with new parameters measured from the initial contrast enema. Initially, an observational study was conducted prospectively on a group of patient with ORSI to define the optimum dose of SBL to achieve full defecatory control with measurement of six parameters in the initial contrast enema (level of colonic dilatation, recto-anal angle, ratio of maximal diameter of dilated colon to last lumbar spine, ratio of maximum diameter of dilated colon to normal descending colon, immediate and after 24-h post-evacuation residual contrast). The result was analyzed statistically to reach a correlation between the radiological data and prescribed dose. Over 2 and half years, 72 patients were included in the study; their mean age was 6.3 ± 3.33 years. The mean effective starting dose of SBL was 57 ± 18.13 mg/day and the mean effective ending dose was 75 ± 31.68 mg/day. Time lapsed till full defecatory control ranged from 1 to 16 weeks. Statistical correlation revealed that mean effective ending dose of SBL treatment significantly increased with higher levels of colonic dilatation. A weak positive correlation was found for both the mean effective starting and ending doses with the ratio of maximum colonic diameter to last lumbar spine and descending colonic diameters ratio. Senna-based laxatives are effective treatment for overflow retentive stool incontinence and their doses can be adjusted initially depending on the analysis of the radiological data.

Development and use of polymerase chain reaction for the specific detection of Salmonella Typhimurium in stool and food samples.

PubMed

Lin, J S; Tsen, H Y

1999-10-01

Salmonella Typhimurium is one of the most important Salmonella serovars that may cause foodborne disease and human salmonellosis infection. Detection of this organism in the clinical samples of persons with gastroenteritis and the food samples associated with such persons may allow us to trace the cause of disease. Because malic acid dehydrogenase, an enzyme of the citric acid cycle, is common to organisms, the gene (mdh) coding for this enzyme was selected for the design of Salmonella Typhimurium-specific polymerase chain reaction (PCR) primers. By comparison of the mdh gene sequences of Salmonella Typhimurium and other Salmonella serotypes and of some isolates of other genera, two oligonucleotides were designed and used as PCR primers for the specific detection of Salmonella Typhimurium. The molecular weight of the PCR product was 261 bp as expected. Salmonella serovars other than Salmonella Typhimurium and isolates of other genera in the Enterobacteriaceae that is closely related to Salmonella did not generate any false-positive results. When this primer pair was used for the detection of Salmonella Typhimurium cells artificially inoculated into human stool specimens and food samples, such as milk and raw chicken meat, levels as low as 10(0) CFU per 0.1 g of stool specimen or per ml of milk or food homogenate could be detected if an 8- to 12-h preculture step using combined lactose-tetrathionate broth was performed prior to the PCR.

Presence of Tablet Remnants of Nevirapine Extended-Release in Stools and Its Impact on Virological Outcome in HIV-1-Infected Patients: A Prospective Cohort Study

PubMed Central

Lee, Yi-Chieh; Lin, Shu-Wen; Chen, Mao-Yuan; Chang, Sui-Yuan; Kuo, Ching-Hua; Sheng, Wang-Huei; Hsieh, Szu-Min; Sun, Hsin-Yun; Chang, Hsi-Yen; Wu, Mon-Ro; Liu, Wen-Chun; Wu, Pei-Ying; Yang, Shang-Ping; Zhang, Jun-Yu; Su, Yi-Ching; Luo, Yi-Zhen; Hung, Chien-Ching; Chang, Shan-Chwen

2015-01-01

Background Nevirapine extended-release (NVP-XR) taken once daily remains an effective antiretroviral agent for patients infected with HIV-1 strains that do not harbor resistance mutations. Presence of tablet remnants of NVP XR in stools was reported in 1.19% and 3.05% of subjects in two clinical trials. However, the prevalence may have been underestimated because the information was retrospectively collected in the studies. Methods Between April and December 2014, we prospectively inquired about the frequency of noticing tablet remnants of NVP XR in stools in HIV-1-infected patients who switched to antiretroviral regimens containing NVP XR plus 2 nucleos(t)ide reverse-transcriptase inhibitors. Patients were invited to participate in therapeutic drug monitoring of plasma concentrations of NVP 12 or 24 hours after taking the previous dose (C12 and C24, respectively) of NVP XR using high-performance liquid chromatography. The information on clinical characteristics, including plasma HIV RNA load and CD4 lymphocyte count, at baseline and during follow-up was recorded. Results During the 9-month study period, 272 patients switched to NVP XR-based regimens and 60 (22.1%) noticed tablet remnants of NVP XR in stools, in whom 54.2% reported noticing the tablet remnants at least once weekly. Compared with patients who did not notice tablet remnants, those who noticed tablet remnants had a higher mean CD4 lymphocyte count (629 vs 495 cells/mm3, P = 0.0002) and a similar mean plasma HIV RNA load (1.57 vs 1.61 log10 copies/mL, P = 0.76) on switch. At about 12 and 24 weeks after switch, patients who noticed tablet remnants continued to have a similar mean plasma HIV RNA load (1.39 vs 1.43 log10 copies/mL, P = 0.43; and 1.30 vs 1.37 log10 copies/mL, P = 0.26, respectively), but had a lower median NVP C12 (3640 vs 4730 ng/mL, P = 0.06), and a similar median NVP C24 (3220 vs 3330 ng/ml, P = 0.95) when compared with those who did not notice tablet remnants. Conclusions The presence

Diagnostic accuracy of three monoclonal stool tests in a large series of untreated Helicobacter pylori infected patients.

PubMed

Lario, Sergio; Ramírez-Lázaro, María José; Montserrat, Antònia; Quílez, María Elisa; Junquera, Félix; Martínez-Bauer, Eva; Sanfeliu, Isabel; Brullet, Enric; Campo, Rafael; Segura, Ferran; Calvet, Xavier

2016-06-01

Immunochromatographic tests need to be improved in order to enhance their reliability. Recently, several new kits have appeared on the market. The objective was to evaluate the diagnostic accuracy of three monoclonal rapid stool tests - the new Uni-Gold™ H.pylori Antigen (Trinity Biotech, Ireland), the RAPID Hp StAR (Oxoid Ltd., UK) and the ImmunoCard STAT! HpSA (Meridian Diagnostics, USA) - for detecting H. pylori infection prior to eradication treatment. Diagnostic accuracy (sensitivity and specificity) and reliability (concordance between observers) were evaluated in 250 untreated consecutive dyspeptic patients. The gold standard for diagnosing H. pylori infection was defined as the concordance of two or more of rapid urease test (RUT), histopathology and urease breath test (UBT) or positive culture in isolation. Readings of immunochromatographic tests were performed by two different observers. Sensitivity, specificity, positive and negative predictive values and 95% confidence intervals were calculated. Sensitivity and specificity were compared using the McNemar test. The three tests showed a good correlation, with Kappa values>0.9. RAPID Hp StAR had a sensitivity of 91%-92% and a specificity ranging from 77% to 85%. Its sensitivity was higher than that of Uni-Gold™ H.pylori Antigen and ImmunoCard STAT! HpSA (p<0.01). Uni-Gold™ H.pylori Antigen kit showed a sensitivity of 83%, similar to ImmunoCard STAT! HpSA. Specificity of Uni-Gold™ H.pylori Antigen approached 90% (87-89%) and was superior to that of RAPID Hp StAR (p<0.01). Uni-Gold™ H.pylori Antigen and ImmunoCard STAT! HpSA present similar levels of diagnostic accuracy. RAPID Hp StAR was the most sensitive but less reliable of the three immunochromatographic stool tests. None are as accurate and reliable as UBT, RUT and histology. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Cholera diagnosis in human stool and detection in water: protocol for a systematic review of available technologies.

PubMed

Diaconu, Karin; Falconer, Jennifer; O'May, Fiona; Jimenez, Miguel; Matragrano, Joe; Njanpop-Lafourcade, Betty; Ager, Alastair

2018-02-20

Cholera is a highly infectious diarrheal disease spread via fecal contamination of water and food sources; it is endemic in parts of Africa and Asia and recent outbreaks have been reported in Haiti, the Zambia and Democratic Republic of the Congo. If left untreated, the disease can be fatal in less than 24 h and result in case fatality ratios of 30-50%. Cholera disproportionately affects those living in areas with poor access to water and sanitation: the long-term public health response is focused on improving water and hygiene facilities and access. Short-term measures for infection prevention and control, and disease characterization and surveillance, are impaired by diagnostic delays: culture methods are slow and rely on the availability of infrastructure and specialist equipment. Rapid diagnostic tests have shown promise under field conditions and further innovations in this area have been proposed. This paper is the protocol for a systematic review focused on identifying current technologies and methods used for cholera diagnosis in stool, and detection in water. We will synthesize and appraise information on product technical specifications, accuracy and design features in order to inform infection prevention and control and innovation development. Embase, MEDLINE, CINAHL, Proquest, IndMed and the WHO and Campbell libraries will be searched. We will include studies reporting on field evaluations, including within-study comparisons against a reference standard, and laboratory evaluations reporting on product validation against field stool or water samples. We will extract data according to protocol and attempt meta-analyses if appropriate given data availability and quality. The systematic review builds on a previous scoping review in this field and expands upon this by synthesising data on both product technical characteristics and design features. The review will be of particular value to stakeholders engaged in diagnostic procurement and manufacturers

Utility of a stool antigen test to detect the incidence of helicobacter pylori infection and familial and community enviromental risk factors for this infection in pediatric age.

PubMed

Sabbi, T; Dall'Oglio, L; De Angelis, P; Torroni, E; Colistro, F; Azzolina, M; Santoni, A; Di Ciommo, V; Benedetto, M

2012-01-01

Helicobacter pylori (Hp) infection is mainly acquired during childhood; it is recognised as a cause of gastritis and peptic ulcer and it has been classified as a group A carcinogen by World Health Organization. The exact mode of transmission is as yet, not known. Aim of our study has been to identify risk factors associated with Helicobacter pylori infection in a preschool and school population and to confirm if Hp antigen in faeces is useful as screening in epidemiological studies. We interviewed, with questionnaire, 400 children (203 male; age range 3-10 years; mean age 6 years) of 3 different schools and stool samples were collected of all children too. 35 of 400 (8%) children underwent to upper gastrointestinal endoscopy because of a suspect of upper gastrointestinal disease. stool were collected from 400 school children and 35 of them shown positivity of Hp antigen test. A questionnaire about presence of nausea, vomit, recurrent abdominal pain, family size, parent's occupations and education, use of antibiotics, country of birth of child and parents, personal hygiene, breast feeding, presence of the animals was completed. 35 children with positive Hp stool antigen test and a suspicious of upper gastrointestinal disease (recurrent abdominal pain, diurnal or nocturnal abdominal pain, nausea, vomiting, iron deficiency) underwent to esophagogastroduodenoscopy (EGDS) that demonstrated antral gastritis and positive histology and urease rapid test. the results of this study suggest that risk factors for Hp infection are low socioeconomics factors, hygiene and living conditions and that Hp antigen in faeces is useful as screening test.

Tocopherol isomer pattern in serum and stool of human following consumption of black currant seed press residue administered in whole grain bread.

PubMed

Helbig, Dorit; Wagner, Andreas; Schubert, Rainer; Jahreis, Gerhard

2009-12-01

Serum gamma-tocopherol is thought to be associated with human health. The dietary influence of tocopherol and fibre-rich black currant seed press residue on serum and stool tocopherol concentration was investigated in a controlled human intervention study. Thirty-six women consumed bread enriched with black currant press residue (4 weeks). The resultant faecal and serum tocopherol concentrations were compared with those after a period consuming control bread without press residue and a normal baseline diet. Fibre intake and excretion, antioxidant capacity (TEAC), and vitamin C concentrations in serum and urine were also determined. Samples were obtained with a 5-day standardised diet at the end of each period. The press residue bread lead to significantly increased beta-, gamma-, delta- and total tocopherol intake, serum alpha-, beta-, gamma- and total tocopherol concentration (with and without lipid adjustment), fibre intake and urinary vitamin C concentration compared to control bread (P<0.05). Faecal excretion of total tocopherols and fibre increased compared to baseline (P<0.05). Fibre intake and excretion influence total tocopherol concentration in lipid-adjusted serum and in stool. The outstandingly high increase of serum gamma-tocopherol concentration through seed press residue consumption could be due to a presumed interruption of the enzymatic tocopherol degradation mechanism by bread constituents.

Detection of Entamoeba histolytica/dispar in stool specimens by using enzyme-linked immunosorbent assay in the population of Jeddah City, Saudi Arabia.

PubMed

Barnawi, Abdulaziz B M; Tonkal, Abulkader M; Fouad, Mahmoud A H; Al-Braiken, Faten A

2007-04-01

This study determined the prevalence of intestinal parasites, particularly pathogenic Entamoeba sp. (E. histolytica), in patients attending three hospitals in Jeddah City, King Abdulaziz University Hospital, King Abdulaziz Hospital and King Fahad Hospital for gastro-intestinal troubles. 186 stool specimens were examined microscopically for parasites and by ELISA kit (E. histolytica II) for true E. histolytica. 83 samples (44.6%) were positive by microscopy for at least one parasite. Of which, 23 (12.4%) showed two parasites and 15 (8.1%) three parasites. Eight different parasite species were identified. The most prevalent were E. histolytica/dispar (n = 26, 31.3%) and Giardia lamblia (n = 13, 15.7%). Others were Blastocytosis hominis (n = 12, 14.5%), Entamoeba coli (n = 11, 13.3%), Trichuris trichuria (n = 8, 9.6%), Endolymax nana (n = 6, 7.2%), Hymenolepes nana (n = 4, 4.8%) and Chilomastix mesnili (n = 3, 3.6%). Only five stool samples (19%) from those identified by microscopy to contain E. histolytica/dispar, were E. histolytica positive by E. histolytica II ELISA. For the first time to the authors' knowledge the true prevalence of E. histolytica in Saudi Arabia was 2.7%. E. histolytica II ELISA proved to be a highly useful technique to differentiate pathogenic E. histolytica from non pathogenic E. dispar.

Detection of Encephalitozoon spp. from human diarrheal stool and farm soil samples in Korea.

PubMed

Kim, Kyungjin; Yoon, Sejoung; Cheun, Hyeng-Il; Kim, Jae-Hwan; Sim, Seobo; Yu, Jae-Ran

2015-03-01

Microsporidia are eukaryotic organisms that cause zoonosis and are major opportunistic pathogens in HIV-positive patients. However, there is increasing evidence that these organisms can also cause gastrointestinal and ocular infections in immunocompetent individuals. In Korea, there have been no reports on human infections with microsporidia to date. In the present study, we used real-time PCR and nucleotide sequencing to detect Encephalitozoon intestinalis infection in seven of 139 human diarrheal stool specimens (5%) and Encephalitozoon hellem in three of 34 farm soil samples (8.8%). Genotype analysis of the E. hellem isolates based on the internal transcribed spacer 1 and polar tube protein genes showed that all isolates were genotype 1B. To our knowledge, this is the first report on human E. intestinalis infection in Korea and the first report revealing farm soil samples as a source of E. hellem infection. Because microsporidia are an important public health issue, further large-scale epidemiological studies are warranted.

Abolition of Ca2+-mediated intestinal anion secretion and increased stool dehydration in mice lacking the intermediate conductance Ca2+-dependent K+ channel Kcnn4

PubMed Central

Flores, Carlos A; Melvin, James E; Figueroa, Carlos D; Sepúlveda, Francisco V

2007-01-01

Intestinal fluid secretion is driven by apical membrane, cystic fibrosis transmembrane conductance regulator (CFTR)-mediated efflux of Cl– that is concentrated in cells by basolateral Na+−K+−2Cl– cotransporters (NKCC1). An absolute requirement for Cl– efflux is the parallel activation of K+ channels which maintain a membrane potential that sustains apical anion secretion. Both cAMP and Ca2+ are intracellular signals for intestinal Cl– secretion. The K+ channel involved in cAMP-dependent secretion has been identified as the KCNQ1–KCNE3 complex, but the identity of the K+ channel driving Ca2+-activated Cl– secretion is controversial. We have now used a Kcnn4 null mouse to show that the intermediate conductance IK1 K+ channel is necessary and sufficient to support Ca2+-dependent Cl– secretion in large and small intestine. Ussing chambers were used to monitor transepithelial potential, resistance and equivalent short-circuit current in colon and jejunum from control and Kcnn4 null mice. Na+, K+ and water content of stools was also measured. Distal colon and small intestinal epithelia from Kcnn4 null mice had normal cAMP-dependent Cl– secretory responses. In contrast, they completely lacked Cl– secretion in response to Ca2+-mobilizing agonists. Ca2+-activated electrogenic K+ secretion was increased in colon epithelium of mice deficient in the IK1 channel. Na+ and water content of stools was diminished in IK1-null animals. The use of Kcnn4 null mice has allowed us to demonstrate that IK1 K+ channels are solely responsible for driving intestinal Ca2+-activated Cl– secretion. The absence of this channel leads to a marked reduction in water content in the stools, probably as a consequence of decreased electrolyte and water secretion. PMID:17584847

Pain symptoms and stooling patterns do not drive diagnostic costs for children with functional abdominal pain and irritable bowel syndrome in primary or tertiary care.

PubMed

Lane, Mariella M; Weidler, Erica M; Czyzewski, Danita I; Shulman, Robert J

2009-03-01

The objectives of this study were to (1) compare the cost of medical evaluation for children with functional abdominal pain or irritable bowel syndrome brought to a pediatric gastroenterologist versus children who remained in the care of their pediatrician, (2) compare symptom characteristics for the children in primary versus tertiary care, and (3) examine if symptom characteristics predicted the cost of medical evaluation. Eighty-nine children aged 7 to 10 years with functional abdominal pain or irritable bowel syndrome seen by a gastroenterologist (n = 46) or seen only by a pediatrician (n = 43) completed daily pain and stool diaries for 2 weeks. Mothers provided retrospective reports of their children's symptoms in the previous year. Cost of medical evaluation was calculated via chart review of diagnostic tests and application of prices as if the patients were self-pay. Child-reported diary data reflected no significant group differences with respect to pain, interference with activities, or stool characteristics. In contrast, mothers of children evaluated by a gastroenterologist viewed their children as having higher maximum pain intensity in the previous year. Excluding endoscopy costs, cost of medical evaluation was fivefold higher for children evaluated by a gastroenterologist, with higher cost across blood work, stool studies, breath testing, and diagnostic imaging. Symptom characteristics did not predict cost of care for either group. Despite the lack of difference in symptom characteristics between children in primary and tertiary care, a notable differential in cost of evaluation exists in accordance with level of care. Symptom characteristics do not seem to drive diagnostic evaluation in either primary or tertiary care. Given the lack of differences in child-reported symptoms and the maternal perspective that children evaluated by a gastroenterologist had more severe pain, we speculate that parent perception of child symptoms may be a primary factor in

Evaluation of Xpert C. difficile, BD MAX Cdiff, IMDx C. difficile for Abbott m2000, and Illumigene C. difficile Assays for Direct Detection of Toxigenic Clostridium difficile in Stool Specimens.

PubMed

Shin, Bo-Moon; Yoo, Sun Mee; Shin, Won Chang

2016-03-01

We evaluated the performance of four commercial nucleic acid amplification tests (NAATs: Xpert C. difficile, BD MAX Cdiff, IMDx C. difficile for Abbott m2000, and Illumigene C. difficile) for direct and rapid detection of Clostridium difficile toxin genes. We compared four NAATs on the same set of 339 stool specimens (303 prospective and 36 retrospective specimens) with toxigenic culture (TC). Concordance rate among four NAATs was 90.3% (306/339). Based on TC results, the sensitivity and specificity were 90.0% and 92.9% for Xpert; 86.3% and 89.3% for Max; 84.3% and 94.4% for IMDx; and 82.4% and 93.7% for Illumigene, respectively. For 306 concordant cases, there were 11 TC-negative/NAATs co-positive cases and 6 TC-positive/NAATs co-negative cases. Among 33 discordant cases, 18 were only single positive in each NAAT (Xpert, 1; Max, 12; IMDx, 1; Illumigene, 4). Positivity rates of the four NAATs were associated with those of semi-quantitative cultures, which were maximized in grade 3 (>100 colony-forming unit [CFU]) compared with grade 1 (<10 CFU). Commercial NAATs may be rapid and reliable methods for direct detection of tcdA and/or tcdB in stool specimens compared with TC. Some differences in the sensitivity of the NAATs may partly depend on the number of toxigenic C. difficile in stool specimens.

Long-Term Frozen Storage of Urine Samples: A Trouble to Get PCR Results in Schistosoma spp. DNA Detection?

PubMed Central

Fernández-Soto, Pedro; Velasco Tirado, Virginia; Carranza Rodríguez, Cristina; Pérez-Arellano, José Luis; Muro, Antonio

2013-01-01

Background Human schistosomiasis remains a serious worldwide public health problem. At present, a sensitive and specific assay for routine diagnosis of schistosome infection is not yet available. The potential for detecting schistosome-derived DNA by PCR-based methods in human clinical samples is currently being investigated as a diagnostic tool with potential application in routine schistosomiasis diagnosis. Collection of diagnostic samples such as stool or blood is usually difficult in some populations. However, urine is a biological sample that can be collected in a non-invasive method, easy to get from people of all ages and easy in management, but as a sample for PCR diagnosis is still not widely used. This could be due to the high variability in the reported efficiency of detection as a result of the high variation in urine samples’ storage or conditions for handling and DNA preservation and extraction methods. Methodology/Principal Findings We evaluate different commercial DNA extraction methods from a series of long-term frozen storage human urine samples from patients with parasitological confirmed schistosomiasis in order to assess the PCR effectiveness for Schistosoma spp. detection. Patientś urine samples were frozen for 18 months up to 7 years until use. Results were compared with those obtained in PCR assays using fresh healthy human urine artificially contaminated with Schistosoma mansoni DNA and urine samples from mice experimentally infected with S. mansoni cercariae stored frozen for at least 12 months before use. PCR results in fresh human artificial urine samples using different DNA based extraction methods were much more effective than those obtained when long-term frozen human urine samples were used as the source of DNA template. Conclusions/Significance Long-term frozen human urine samples are probably not a good source for DNA extraction for use as a template in PCR detection of Schistosoma spp., regardless of the DNA method of

Detection of enteropathogens associated with travelers' diarrhea using a multiplex Luminex-based assay performed on stool samples smeared on Whatman FTA Elute cards.

PubMed

Lalani, Tahaniyat; Tisdale, Michele D; Maguire, Jason D; Wongsrichanalai, Chansuda; Riddle, Mark S; Tribble, David R

2015-09-01

We evaluated the limits of detection (LoD) for an 11-plex PCR-Luminex assay performed on Whatman(™) FTA Elute cards smeared with stool containing pathogens associated with travelers' diarrhea. LoDs ranged from 10(2) to 10(5)CFU, PFU, or cysts/g for most pathogens except Cryptosporidium. Campylobacter and norovirus LoDs increased with prolonged storage of cards. Copyright © 2015 Elsevier Inc. All rights reserved.

[Recommendations for the use of faecal microbiota transplantation "stool transplantation": consensus of the Austrian Society of Gastroenterology and Hepatology (ÖGGH) in cooperation with the Austrian Society of Infectious Diseases and Tropical Medicine].

PubMed

Kump, P K; Krause, R; Steininger, C; Gröchenig, H P; Moschen, A; Madl, C; Novacek, G; Allerberger, F; Högenauer, C

2014-12-01

The intestinal microbiota has a pivotal role in the maintenance of health of the human organism, especially in the defense against pathogenic microorganisms. Alterations in the microbiota, also termed dysbiosis, seem to be involved in the pathogenesis of a variety of intestinal and extraintestinal diseases. Fecal microbiota transplantation (FMT), also known as stool transplantation, is a therapeutic procedure aiming at restoring an altered intestinal microbiota by administration of stool microorganisms from a healthy donor into the intestinal tract of a patient. FMT is most commonly used for recurrent forms of Clostridium difficile infections (CDI). There are currently many cohort studies in a large number of patients and a randomized controlled trial showing a dramatic effect of FMT for this indication. Therefore FMT is recommended by international medical societies for the treatment of recurrent CDI with high scientific evidence. Other potential indications are the treatment of fulminant CDI or the treatment of inflammatory bowel diseases. In the practical utilization of FMT there are currently several open questions regarding the screening of stool donors, the processing of stool and the mode of FMT application. Different modes of FMT application have been described, the application into the colon has to be preferred due to less reported side effects than the application into the upper gastrointestinal tract. So far only very few side effects due to FMT have been reported, nevertheless the use and risks of FMT are currently intensely debated in the medical community. This consensus report of the Austrian society of gastroenterology and hepatology (ÖGGH) in cooperation with the Austrian society of infectious diseases and tropical medicine provides instructions for physicians who want to use FMT which are based on the current medical literature. © Georg Thieme Verlag KG Stuttgart · New York.

Differences in prevalence of parasites in stool samples between three distinct ethnic pediatric populations in southern Israel, 2007-2011.

PubMed

Ben-Shimol, Shalom; Sagi, Orli; Greenberg, David

2014-04-01

Intestinal parasites cause significant morbidity worldwide, particularly in developing populations. At least three pediatric populations reside in southern Israel: the Bedouin population, the general Jewish population and Jewish children of Ethiopian origin. Our aim was to compare intestinal parasite prevalence between the three pediatric populations in southern Israel. This is a retrospective, laboratory, population-based surveillance. Most ova and parasite (O&P) tests in southern Israel (hospital and community obtained) are performed by the hospital parasitology laboratory. All pediatric stool O&P tests examined by the hospital laboratory between 2007 and 2011 were included. Overall, 45,978 samples were examined; 27,354, 16,969 and 1655 from Bedouin, non-Ethiopian Jewish and Ethiopian children, respectively. 16,317 parasites were identified in 12,325 (26.8%) positive samples. Total prevalences were 36%, 11% and 46% for Bedouin, non-Ethiopian Jewish and Ethiopian children, respectively. Blastocystis hominis, Giardia lamblia and Entamoeba species were the most common parasites identified, constituting ≥80% of positive samples in all groups. Hymenolepis nana was rarely identified in non-Ethiopian Jewish children (0.04% of isolates compared with 2.6% and 0.5% in Bedouin and Ethiopian children, respectively). Other helminths, excluding H. nana and Enterobius vermicularis, were identified almost exclusively in Ethiopian children ≥5years of age. In conclusion, the Bedouin and Ethiopian children were characterized by higher parasite prevalence in stool, compared with the non-Ethiopian Jewish children, probably reflecting higher intestinal parasitic disease rates. Certain helminthic infections were identified almost exclusively in the Ethiopian children. These differences may be associated with lifestyle differences between the three populations. © 2013.

Does an L-glutamine-containing, Glucose-free, Oral Rehydration Solution Reduce Stool Output and Time to Rehydrate in Children with Acute Diarrhoea? A Double-blind Randomized Clinical Trial

PubMed Central

Gutiérrez, Claudia; Villa, Sofía; Mota, Felipe R.; Calva, Juan J.

2007-01-01

This study assessed whether an oral rehydration solution (ORS) in which glucose is replaced by L-glutamine (L-glutamine ORS) is more effective than the standard glucose-based rehydration solution recommended by the World Health Organization (WHO-ORS) in reducing the stool volume and time to rehydrate in acute diarrhoea. In a double-blind, randomized controlled trial in a Mexican hospital, 147 dehydrated children, aged 1–60 month(s), were assigned either to the WHO-ORS (74 children), or to the L-glutamine ORS (73 children) and followed until successful rehydration. There were no significant differences between the groups in stool output during the first four hours, time to successful rehydration, volume of ORS required for rehydration, urinary output, and vomiting. This was independent of rotavirus-associated infection. An L-glutamine-containing glucose-free ORS seems not to offer greater clinical benefit than the standard WHO-ORS in mildly-to-moderately-dehydrated children with acute non-cholera diarrhoea. PMID:18330060

Active BRAF-V600E is the key player in generation of a sessile serrated polyp-specific DNA methylation profile

PubMed Central

Dehghanizadeh, Somaye; Khoddami, Vahid; Mosbruger, Timothy L.; Hammoud, Sue S.; Edes, Kornelia; Berry, Therese S.; Done, Michelle; Samowitz, Wade S.; DiSario, James A.; Luba, Daniel G.; Burt, Randall W.

2018-01-01

Background Sessile serrated polyps (SSPs) have emerged as important precursors for a large number of sporadic colorectal cancers. They are difficult to detect during colonoscopy due to their flat shape and the excessive amounts of secreted mucin that cover the polyps. The underlying genetic and epigenetic basis for the emergence of SSPs is largely unknown with existing genetic studies confined to a limited number of oncogenes and tumor suppressors. A full characterization of the genetic and epigenetic landscape of SSPs would provide insight into their origin and potentially offer new biomarkers useful for detection of SSPs in stool samples. Methods We used a combination of genome-wide mutation detection, exome sequencing and DNA methylation profiling (via methyl-array and whole-genome bisulfite sequencing) to analyze multiple samples of sessile serrated polyps and compared these to familial adenomatous polyps. Results Our analysis revealed BRAF-V600E as the sole recurring somatic mutation in SSPs with no additional major genetic mutations detected. The occurrence of BRAF-V600E was coincident with a unique DNA methylation pattern revealing a set of DNA methylation markers showing significant (~3 to 30 fold) increase in their methylation levels, exclusively in SSP samples. These methylation patterns effectively distinguished sessile serrated polys from adenomatous polyps and did so more effectively than parallel gene expression profiles. Conclusions This study provides an important example of a single oncogenic mutation leading to reproducible global DNA methylation changes. These methylated markers are specific to SSPs and could be of important clinical relevance for the early diagnosis of SSPs using non-invasive approaches such as fecal DNA testing. PMID:29590112

Detection and quantitation of single nucleotide polymorphisms, DNA sequence variations, DNA mutations, DNA damage and DNA mismatches

DOEpatents

McCutchen-Maloney, Sandra L.

2002-01-01

DNA mutation binding proteins alone and as chimeric proteins with nucleases are used with solid supports to detect DNA sequence variations, DNA mutations and single nucleotide polymorphisms. The solid supports may be flow cytometry beads, DNA chips, glass slides or DNA dips sticks. DNA molecules are coupled to solid supports to form DNA-support complexes. Labeled DNA is used with unlabeled DNA mutation binding proteins such at TthMutS to detect DNA sequence variations, DNA mutations and single nucleotide length polymorphisms by binding which gives an increase in signal. Unlabeled DNA is utilized with labeled chimeras to detect DNA sequence variations, DNA mutations and single nucleotide length polymorphisms by nuclease activity of the chimera which gives a decrease in signal.

Distribution of Parasites Detected in Stool Samples of Patients Admitted to Our Parasitology Laboratory during a Three-Year Period between 2012 and 2014.

PubMed

Selek, Mehmet Burak; Bektöre, Bayhan; Karagöz, Ergenekon; Baylan, Orhan; Özyurt, Mustafa

2016-09-01

Parasitic diseases are among the major public health issues worldwide. A number of tests are available for diagnosis, but the sentivity and specifity of these tests are assumed to be insufficient. Nevertheless, the most common diagnostic method is microscopic examination. In this study, we aimed to introduce the distribution of parasites detected in stool samples of patients admitted to our laboratory on the basis of parameters such as, age, and gender during a 3-year period between 2012 and 2014. In total, 6757 stool samples were included in the study. After macroscopic examination, wet mounts of all samples were examined under a light microscope using ×100 and ×400 magnification lenses. Wet mounts were prepared with physiological saline and Lugol's iodine. Parasites were detected in 3.7% (252) of the samples, while no parasites were detected in 96.3% (6505) of the samples. The distribution of intestinal parasites was as follows: Blastocystis hominis (63.5%), Giardia intestinalis (26.2%), Taenia sp. (4.8%), Enterobius vermicularis (2.4%), Entamoeba histolytica/dispar (1.6%), and Hymenolepis nana (1.6%). When the burden of intestinal parasites on public health is considered, they are still a major health issue in Turkey. The frequency of parasitic diseases can be reduced by the education of individuals and implementation of effective diagnostic methods, treatments, and preventive measures.

A Microbiomic Analysis in African Americans with Colonic Lesions Reveals Streptococcus sp.VT162 as a Marker of Neoplastic Transformation

PubMed Central

Brim, Hassan; Yooseph, Shibu; Lee, Edward; Sherif, Zaki A.; Abbas, Muneer; Laiyemo, Adeyinka O.; Varma, Sudhir; Torralba, Manolito; Dowd, Scot E.; Nelson, Karen E.; Pathmasiri, Wimal; Sumner, Susan; de Vos, Willem; Liang, Qiaoyi; Yu, Jun; Zoetendal, Erwin; Ashktorab, Hassan

2017-01-01

Increasing evidence suggests a role of the gut microbiota in colorectal carcinogenesis (CRC). To detect bacterial markers of colorectal cancer in African Americans a metabolomic analysis was performed on fecal water extracts. DNA from stool samples of adenoma and healthy subjects and from colon cancer and matched normal tissues was analyzed to determine the microbiota composition (using 16S rDNA) and genomic content (metagenomics). Metagenomic functions with discriminative power between healthy and neoplastic specimens were established. Quantitative Polymerase Chain Reaction (q-PCR) using primers and probes specific to Streptococcus sp. VT_162 were used to validate this bacterium association with neoplastic transformation in stool samples from two independent cohorts of African Americans and Chinese patients with colorectal lesions. The metabolomic analysis of adenomas revealed low amino acids content. The microbiota in both cancer vs. normal tissues and adenoma vs. normal stool samples were different at the 16S rRNA gene level. Cross-mapping of metagenomic data led to 9 markers with significant discriminative power between normal and diseased specimens. These markers identified with Streptococcus sp. VT_162. Q-PCR data showed a statistically significant presence of this bacterium in advanced adenoma and cancer samples in an independent cohort of CRC patients. We defined metagenomic functions from Streptococcus sp. VT_162 with discriminative power among cancers vs. matched normal and adenomas vs. healthy subjects’ stools. Streptococcus sp. VT_162 specific 16S rDNA was validated in an independent cohort. These findings might facilitate non-invasive screening for colorectal cancer. PMID:29120399

Comparison of four chromogenic media and Hektoen agar for detection and presumptive identification of Salmonella strains in human stools.

PubMed

Perez, J M; Cavalli, P; Roure, C; Renac, R; Gille, Y; Freydiere, A M

2003-03-01

Several chromogenic media have been developed to enhance the specificity of Salmonella detection. We compared the performance of four commercial chromogenic media-namely, ABC medium (Lab M. Ltd., Bury, United Kingdom), COMPASS Salmonella agar (Biokar Diagnostics, Beauvais, France), CHROMagar Salmonella agar (CHROMagar Company, Paris, France), and SM ID agar (bioMerieux, Marcy l'Etoile, France)-with conventional Hektoen medium. Nine hundred sixteen stool samples from inpatients at three hospitals were cultured, in parallel, on the five media, both by direct inoculation and after selective enrichment in selenite broth. Sixty-four Salmonella strains with 12 serotypes were isolated on at least one medium. After 48 h of incubation, sensitivity before and after enrichment was 62.5 and 89.1% with ABC medium, 77.1 and 93.8% with COMPASS agar, 66.7 and 89.1% with CHROMagar, 68.8 and 85.9% with SM ID agar, and 85.4 and 98.4% with Hektoen agar, respectively. Broth enrichment and prolonged incubation (48 versus 24 h) increased the sensitivity of all five media. Only one strain was not isolated on Hektoen agar. The number of false-positive isolates was higher with all five media after enrichment in selenite broth and after incubation for 48 h compared to 24 h. The specificity of the four chromogenic media was better than 91% after incubation for 24 h (77.7% with Hektoen agar) and better than 84% after incubation for 48 h (74.8% with Hektoen agar). This higher specificity reduces the need for confirmatory tests, thereby cutting technical time and reagent requirements. Both COMPASS agar and CHROMagar Salmonella, which after simple additional tests showed close efficiencies (96 and 97%, respectively), can be recommended as single-plate media of choice for the detection and presumptive identification of salmonellae in stools.

Simultaneous occurrence of MRSA and ESBL-producing Enterobacteriaceae on pig farms and in nasal and stool samples from farmers.

PubMed

Fischer, Julia; Hille, Katja; Ruddat, Inga; Mellmann, Alexander; Köck, Robin; Kreienbrock, Lothar

2017-02-01

Methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum β-lactamase (ESBL) producing enterobacteria (ESBL-E) have emerged in livestock. This study prospectively investigates the prevalence of MRSA and ESBL-E on pig farms and in nasal and stool samples from farmers and compares molecular characteristics of these ESBL-E isolates. In 2014, samples were derived at 51 pig farms in Germany. Per farm, five dust and five fecal samples were collected; one nasal and one stool sample were retrieved from farmers. ESBL-E isolates from humans and environmental isolates from the respective farms were characterized using whole genome sequencing for classical multilocus sequence typing (MLST), determination of ESBL-encoding genes and an ad hoc core genome MLST (cgMLST) analysis. MRSA and ESBL-E were detected on 49 (96%) and 31 (61%) of the farms, respectively; in most cases (59%) simultaneously. Nasal MRSA carriage was detected in 72 of 85 (84.7%) farmers and five of 84 (6.0%) farmers carried ESBL-E. ESBL-Escherichia coli isolates from farmers belonged to MLST STs/ESBL-genes ST10/CTX-M-1, ST196/TEM-52, ST278/TEM-52, ST410/CTX-M-15 and ST453/CTX-M-1. In one case, the human ESBL-E isolate was clonally identical to isolates from the farm environment; in the other four cases typing results indicated potential exchange of resistance determinants between human and environmental isolates, but, comparing the isolates within a minimum spanning tree indicated differences in cgMLST-patterns between the farms (p=0.076). This study demonstrated rectal ESBL-E carriage rates among farmers, which were similar to those in the general population. Molecular typing suggested that cross-transmission between the farmers and the farm environment is possible. Copyright © 2016 Elsevier B.V. All rights reserved.

Performance of the chromID Salmonella Elite chromogenic agar in comparison with CHROMagar™ Salmonella, Oxoid™ Brilliance™ Salmonella and Hektoen agars for the isolation of Salmonella from stool specimens.

PubMed

Martiny, Delphine; Dediste, Anne; Anglade, Claire; Vlaes, Linda; Moens, Catherine; Mohamed, Souad; Vandenberg, Olivier

2016-10-01

chromID™ Salmonella Elite is compared with 3 culture media commonly used for Salmonella isolation from stool specimens. As results were equivalent to other chromogenic media (100% sensitivity, 98% specificity), only financial arguments should guide the choice for a medium with respect to another. Copyright © 2016 Elsevier Inc. All rights reserved.

Performance of the Fecal Immunochemical Test for Colorectal Cancer Screening Using Different Stool-Collection Devices: Preliminary Results from a Randomized Controlled Trial.

PubMed

Shin, Hye Young; Suh, Mina; Baik, Hyung Won; Choi, Kui Son; Park, Boyoung; Jun, Jae Kwan; Hwang, Sang-Hyun; Kim, Byung Chang; Lee, Chan Wha; Oh, Jae Hwan; Lee, You Kyoung; Han, Dong Soo; Lee, Do-Hoon

2016-11-15

We are in the process of conducting a randomized trial to determine whether compliance with the fecal immunochemical test (FIT) for colorectal cancer screening differs according to the stool-collection method. This study was an interim analysis of the performance of two stool-collection devices (sampling bottle vs conventional container). In total, 1,701 individuals (age range, 50 to 74 years) were randomized into the sampling bottle group (intervention arm) or the conventional container group (control arm). In both groups, we evaluated the FIT positivity rate, the positive predictive value for advanced neoplasia, and the detection rate for advanced neoplasia. The FIT positivity rates were 4.1% for the sampling bottles and 2.0% for the conventional containers; these values were significantly different. The positive predictive values for advanced neoplasia in the sampling bottles and conventional containers were 11.1% (95% confidence interval [CI], -3.4 to 25.6) and 12.0% (95% CI, -0.7 to 24.7), respectively. The detection rates for advanced neoplasia in the sampling bottles and conventional containers were 4.5 per 1,000 persons (95% CI, 2.0 to 11.0) and 2.4 per 1,000 persons (95% CI, 0.0 to 5.0), respectively. The impact of these findings on FIT screening performance was unclear in this interim analysis. This impact should therefore be evaluated in the final analysis following the final enrollment period.

Agreement between prospective diary data and retrospective questionnaire report of abdominal pain and stooling symptoms in children with irritable bowel syndrome.

PubMed

Self, M M; Williams, A E; Czyzewski, D I; Weidler, E M; Shulman, R J

2015-08-01

In functional gastrointestinal disorders, patient recall of symptoms drives diagnostic decisions and evaluation of treatment response, and research conclusions about potential treatments. In pediatrics, parent report also impacts assessment and care. Hence, identifying methods for accurately capturing patient and parent report of irritable bowel syndrome (IBS) symptoms is important. This study evaluated correspondence between retrospective questionnaire (parent and child report) and prospective diary data for children and adolescents with IBS. Participants included 50 children/adolescents with IBS per Rome III criteria. Children completed a 2-week pain and stool diary. Children and parents subsequently completed a 2-week recall questionnaire, reporting number of pain days, maximum pain, days without bowel movement, and days with diarrhea during the diary interval. Intraclass correlation coefficients and Bland-Altman plots assessed agreement. For pain and days without bowel movement, overall agreement between child recall questionnaire and child diary was strong, although under conditions likely to facilitate agreement and with individual variation observed. Parent recall and child diary were less concordant, and agreement about diarrhea was poor for parent and child. Age did not significantly correlate with agreement. Child questionnaire with short recall interval may be a reasonable approximation for diary data, although this varies by individual and replication/investigation of lengthier recall are needed. Relying on parent questionnaire does not appear a suitable proxy, and recall of stool form by both parent and child appears more problematic. These results combined with existing literature support use of diary data whenever possible. © 2015 John Wiley & Sons Ltd.

Detection of Treponema Denticola in Symptomatic Apical Periodontitis and in Symptomatic Apical Abscesses by Real-Time PCR

PubMed Central

Ozbek, Selcuk M.; Ozbek, Ahmet; Erdogan, Aziz S.

2009-01-01

Objectives: The aim of this study was to investigate the presence of Treponema denticola in symptomatic apical periodontitis and in symptomatic apical abscesses by real-time polymerase chain reaction (PCR) method. Methods: Microbial samples were collected from 60 single-rooted teeth having carious lesions and necrotic pulps. For each tooth, clinical data including patient symptoms were recorded. Teeth were categorized by diagnosis as having symptomatic apical periodontitis or symptomatic apical abscess. Aseptic microbial samples were collected using paper points from 30 infected root canals and from aspirates of 30 abscesses. DNA was extracted from the samples by using a QIAamp® DNA mini-kit and analyzed with real-time PCR. Results: T. denticola was detected in 24 of 30 cases diagnosed as symptomatic apical abscesses (80%), and 19 of 30 cases diagnosed as symptomatic apical periodontitis (63.3%). In general T. denticola was found in 43 of 60 cases (71.6%). Conclusions: Our findings suggest that T. denticola can participate in the pathogenesis of symptomatic apical abscesses. PMID:19421390

Prevalence and genetic diversity of torque teno virus in patients with systemic lupus erythematosus in a reference service in Mato Grosso do Sul.

PubMed

Costa, Márcio Reis da; Costa, Izaias Pereira da; Devalle, Sylvie; Castro, Ana Rita Coimbra Motta de; Freitas, Solange Zacalusni

2012-01-01

Recent studies on the torque teno virus (TTV), genus Anellovirus, have allowed formulating the hypothesis that TTV may trigger autoimmune rheumatic diseases or have some pathogenic role in them. To determine the frequency of TTV infection in patients with systemic lupus erythematosus (SLE), the genetic diversity of TTV, the correlation between TTV infection and SLE clinical manifestations, and SLE clinical course and serological profile. Serum samples were obtained from 46 SLE patients treated at the University-Affiliated Hospital of Campo Grande (NHU/FAMED/UFMS), Brazil. For controls, serum samples were obtained from 46 healthy volunteer blood donors. Viral DNA was extracted from samples using the QIAamp DNA Blood Mini Kit (QIAGEN, Hilden, Germany) and amplified using nested PCR. Positivity for TTV was found in 17 (37%) of SLE patients and in only seven (15.2%) of the controls (z test, P = 0.03). There was no correlation between TTV infection, SLE clinical manifestations, SLE clinical course, and the serological profile of the patients evaluated. Further studies on the presence of TTV in SLE patients are required.

Synthesis, structure, DNA binding and anticancer activity of mixed ligand ruthenium(II) complex

NASA Astrophysics Data System (ADS)

Gilewska, Agnieszka; Masternak, Joanna; Kazimierczuk, Katarzyna; Trynda, Justyna; Wietrzyk, Joanna; Barszcz, Barbara

2018-03-01

In order to obtain a potential chemotherapeutic which is not affected on the normal BALB/3T3 cell line, a new arene ruthenium(II) complex {[RuCl(L1)(η6-p-cymene)]PF6}2 · H2O has been synthesized by a direct reaction of precursor, [{(η6-p-cymene)Ru(μ-Cl)}2Cl2], with N,N-chelating ligand (L1 - 2,2‧-bis(4,5-dimethylimidazole). The compound has been fully characterized by elemental analysis, X-ray diffraction, IR, UV-Vis and 1H, 13C NMR spectroscopies. X-ray analysis have confirmed that the compound crystallized in the monoclinic group Cc as an inversion twin. The asymmetric unit contains two symmetrically independent cationic complexes [RuCl(L1)(η6-p-cymene)]+ whose charge is balanced by two PF6- counterions. The shape of each cationic coordination polyhedral can be described as a distorted dodecahedron and shows a typical piano-stool geometry. In addition, an analysis of the crystal structure and the Hirshfeld surface analysis were used to detect and visualize important hydrogen bonds and intermolecular interaction. Moreover, the antiproliferative behavior of the obtained complex was assayed against three human cells: MV-4-11, LoVo, MCF-7 and BALB/3T3 - normal mice fibroblast cells. To predict a binding mode, a potential interaction of ruthenium complex with calf thymus DNA (CT-DNA) has been explored using UV absorption and circular dichroism (CD).

Highly sensitive and specific detection of Giardia duodenalis, Entamoeba histolytica, and Cryptosporidium spp. in human stool samples by the BD MAX™ Enteric Parasite Panel.

PubMed

Parčina, Marijo; Reiter-Owona, Ingrid; Mockenhaupt, Frank P; Vojvoda, Valerija; Gahutu, Jean Bosco; Hoerauf, Achim; Ignatius, Ralf

2018-02-01

Detection of intestinal protozoan parasites by light microscopy is cumbersome, needs experienced personnel, and may lack sensitivity and/or specificity as compared with molecular-based stool assays. Here, we evaluated the BD MAX™ Enteric Parasite Panel, i.e., a multiplex real-time PCR assay for simultaneous detection of Giardia duodenalis, Entamoeba histolytica, and cryptosporidia (Cryptosporidium parvum and C. hominis), by examining 200 positive human stool samples (138 × G. duodenalis, 27 × E. histolytica, 35 × Cryptosporidium spp.) and 119 controls including 18 samples with E. dispar. The majority of the samples, i.e., 153/200 (76.5%) positive samples and 66/119 (55.5%) controls, were confirmed by multiplex in-house PCR detecting the same parasites as the BD MAX™ Enteric Parasite Panel. The BD MAX™ assay did not yield false-positive results. Sensitivity and specificity were 97.8% (95% CI, 93.3-99.4%) and 100% (95% CI, 97.4-100%) for G. duodenalis, 100% (95% CI, 84.5-100%) and 100% (95% CI, 98.4-100%) for E. histolytica, and 100% (95% CI, 87.7-100%) and 100% (95% CI, 98.3-100%) for cryptosporidia, and similar data were obtained when only the 219 PCR-confirmed samples were analyzed. Thus, the BD MAX™ Enteric Parasite Panel provides a highly sensitive and specific tool for the laboratory diagnosis of three predominant protozoan parasites causing enteritis.

Chimeric proteins for detection and quantitation of DNA mutations, DNA sequence variations, DNA damage and DNA mismatches

DOEpatents

McCutchen-Maloney, Sandra L.

2002-01-01

Chimeric proteins having both DNA mutation binding activity and nuclease activity are synthesized by recombinant technology. The proteins are of the general formula A-L-B and B-L-A where A is a peptide having DNA mutation binding activity, L is a linker and B is a peptide having nuclease activity. The chimeric proteins are useful for detection and identification of DNA sequence variations including DNA mutations (including DNA damage and mismatches) by binding to the DNA mutation and cutting the DNA once the DNA mutation is detected.

Comparison of CHROMagar Salmonella Medium and Xylose-Lysine-Desoxycholate and Salmonella-Shigella Agars for Isolation of Salmonella Strains from Stool Samples

PubMed Central

Maddocks, Susan; Olma, Tom; Chen, Sharon

2002-01-01

The growth and appearance of 115 stock Salmonella isolates on a new formulation of CHROMagar Salmonella (CAS) medium were compared to those on xylose-lysine-desoxycholate agar (XLD), Salmonella-Shigella agar (SS), and Hektoen enteric agar (HEA) media. CAS medium was then compared prospectively to XLD and SS for the detection and presumptive identification of Salmonella strains in 500 consecutive clinical stool samples. All stock Salmonella isolates produced typical mauve colonies on CAS medium. Nine Salmonella strains were isolated from clinical specimens. The sensitivities for the detection of salmonellae after primary plating on CAS medium and the combination of XLD and SS after enrichment were 100%. The specificity for the detection of salmonellae after primary plating on CAS medium (83%) was significantly (P < 0.0001) higher than that after primary plating on the combination of SS and XLD media (55%) (a 28% difference in rates; 95% confidence interval, 23.0 to 34%). Twenty-nine non-Salmonella organisms produced mauve colonies on CAS medium, including 17 Candida spp. (59%) and 8 Pseudomonas spp. (28%). These were easily excluded as salmonellae by colony morphology, microscopic examination of a wet preparation, or oxidase testing. One biochemically inert Escherichia coli isolate required further identification to differentiate it from Salmonella spp. The use of plating on CAS medium demonstrated high levels of sensitivity and specificity and reduced the time to final identification of Salmonella spp., resulting in substantial cost savings. It can be recommended for use for the primary isolation of Salmonella spp. from stool specimens. Other media (e.g., XLD) are required to detect Shigella spp. concurrently. PMID:12149365

Unusual mode of protein binding by a cytotoxic π-arene ruthenium(ii) piano-stool compound containing an O,S-chelating ligand.

PubMed

Hildebrandt, Jana; Görls, Helmar; Häfner, Norman; Ferraro, Giarita; Dürst, Matthias; Runnebaum, Ingo B; Weigand, Wolfgang; Merlino, Antonello

2016-08-02

A new pseudo-octahedral π-arene ruthenium(ii) piano-stool compound, containing an O,S-bidentate ligand (compound 1) and showing significant cytotoxic activity in vitro, was synthesized and characterized. In solution stability and interaction with the model protein bovine pancreatic ribonuclease (RNase A) were investigated by using UV-Vis absorption spectroscopy. Its crystal structure and that of the adduct formed upon reaction with RNase A were obtained by X-ray crystallography. The comparison between the structure of purified compound 1 and that of the fragment bound to RNase A reveals an unusual mode of protein binding that includes ligand exchange and alteration of coordination sphere geometry.

High-throughput sequencing of fecal DNA to identify insects consumed by wild Weddell's saddleback tamarins (Saguinus weddelli, Cebidae, Primates) in Bolivia.

PubMed

Mallott, E K; Malhi, R S; Garber, P A

2015-03-01

The genus Saguinus represents a successful radiation of over 20 species of small-bodied New World monkeys. Studies of the tamarin diet indicate that insects and small vertebrates account for ∼16-45% of total feeding and foraging time, and represent an important source of lipids, protein, and metabolizable energy. Although tamarins are reported to commonly consume large-bodied insects such as grasshoppers and walking sticks (Orthoptera), little is known concerning the degree to which smaller or less easily identifiable arthropod prey comprises an important component of their diet. To better understand tamarin arthropod feeding behavior, fecal samples from 20 wild Bolivian saddleback tamarins (members of five groups) were collected over a 3 week period in June 2012, and analyzed for the presence of arthropod DNA. DNA was extracted using a Qiagen stool extraction kit, and universal insect primers were created and used to amplify a ∼280 bp section of the COI mitochondrial gene. Amplicons were sequenced on the Roche 454 sequencing platform using high-throughput sequencing techniques. An analysis of these samples indicated the presence of 43 taxa of arthropods including 10 orders, 15 families, and 12 identified genera. Many of these taxa had not been previously identified in the tamarin diet. These results highlight molecular analysis of fecal DNA as an important research tool for identifying anthropod feeding patterns in primates, and reveal broad diversity in the taxa, foraging microhabitats, and size of arthropods consumed by tamarin monkeys. © 2014 Wiley Periodicals, Inc.

Development of a nested polymerase chain reaction for amplification of a sequence of the p57 gene of Renibacterium salmoninarum that provides a highly sensitive method for detection of the bacterium in salmonid kidney

USGS Publications Warehouse

Chase, D.M.; Pascho, R.J.

1998-01-01

Nucleic acid-based assays have shown promise for diagnosing Renibacterium salmoninarum in tissues and body fluids of salmonids. DeVelopment of a nested polymerase chain reaction (PCR) method to detect a 320 bp DNA segment of the gene encoding the p57 protein of R. salmoninarum is described. Whereas a conventional PCR for a 383 bp segment of the p57 gene reliably detected 1000 R. salmoninarum cells per reaction in kidney tissue, the nested PCR detected as few as 10 R. salmoninarum per reaction in kidney tissue. Two DNA extraction methods for the nested PCR were compared and the correlation between replicate samples was generally higher in samples extracted by the QIAamp system compared with those extracted by the phenol/chloroform method. The specificity of the nested PCR was confirmed by testing DNA extracts of common bacterial fish pathogens and a panel of bacterial species reported to cause false-positive reactions in the enzyme-linked immunosorbent assay (ELISA) and the fluorescent antibody test (FAT) for R. salmoninarum. Kidney samples from 74 naturally infected chinook Salmon were examined by the nested PCR, the ELISA, and the FAT, and the detected prevalences of R. salmoninarum were 61, 47, and 43%, respectively.

Regulating DNA Self-assembly by DNA-Surface Interactions.

PubMed

Liu, Longfei; Li, Yulin; Wang, Yong; Zheng, Jianwei; Mao, Chengde

2017-12-14

DNA self-assembly provides a powerful approach for preparation of nanostructures. It is often studied in bulk solution and involves only DNA-DNA interactions. When confined to surfaces, DNA-surface interactions become an additional, important factor to DNA self-assembly. However, the way in which DNA-surface interactions influence DNA self-assembly is not well studied. In this study, we showed that weak DNA-DNA interactions could be stabilized by DNA-surface interactions to allow large DNA nanostructures to form. In addition, the assembly can be conducted isothermally at room temperature in as little as 5 seconds. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Efficacy of stool antigen and serologic tests in the diagnosis of Helicobacter pylori in Ecuadorian population].

PubMed

Gómez, Néstor A; Alvarez, Ludwig R; Zapatier, Jorge A; Vargas, Paola E

2005-01-01

To assess the effectiveness in the Ecuadorian population of 2 non-invasive methods for the detection of the Helicobacter pylori: the stool antigens immunoassay (HpSAg) and the determination IgG serum of'antibodies. Eighty six dyspeptic patients were evaluated. In each, Helicobacter pylori presence was investigated with three methods: histology, HpSAg and serology. Sensibility and specificity values were obtained, as well as the positive and negative predictive values. The prevalence of Helicobacter pylori with the 3 tests was 89.53%. The sensibility, specificity, positive predictive value, and negative predictive value were: 42.5%, 69.2%, 88.6% and 17.6% with histology; 69.2%, 42.9%, 78.9% and 31% with HpSAg; 64.2%, 47.7%, 81.1% and 27.3% with serology. In the highly prevalent Ecuadorian setting, HpSAg and serology have relative low sensibility and specificity values. Based on our results, it is necessary to assess for conditions that could alter their results, and strategies to increase the sensibility of these tests, including the histology.

Performances of Four Helicobacter pylori Serological Detection Kits Using Stool Antigen Test as Gold Standard.

PubMed

Biranjia-Hurdoyal, Susheela D; Seetulsingh-Goorah, Sharmila P

2016-01-01

The aim was to determine the performances of four Helicobacter pylori serological detection kits in different target groups, using Amplified IDEIA™ Hp StAR™ as gold standard. Kits studied were Rapid Immunochromatoghraphic Hexagon, Helicoblot 2.1, an EIA IgG kit and EIA IgA kit. Stool and blood samples were collected from 162 apparently healthy participants (control) and 60 Type 2 diabetes mellitus (T2DM) patients. The performances of the four serological detection kits were found to be affected by gender, age, health status and ethnicity of the participants. In the control group, the Helicoblot 2.1 kit had the best performance (AUC = 0.85; p<0.05, accuracy = 86.4%), followed by EIA IgG (AUC = 0.75; p<0.05, accuracy = 75.2%). The Rapid Hexagon and EIA IgA kits had relatively poor performances. In the T2DM subgroup, the kits H2.1 and EIA IgG had best performances, with accuracies of 96.5% and 93.1% respectively. The performance of EIA IgG improved with adjustment of its cut-off value. The performances of the detection kits were affected by various factors which should be taken into consideration.

Sperm DNA oxidative damage and DNA adducts

PubMed Central

Jeng, Hueiwang Anna; Pan, Chih-Hong; Chao, Mu-Rong; Lin, Wen-Yi

2015-01-01

The objective of this study was to investigate DNA damage and adducts in sperm from coke oven workers who have been exposed to polycyclic aromatic hydrocarbons. A longitudinal study was conducted with repeated measurements during spermatogenesis. Coke-oven workers (n=112) from a coke-oven plant served the PAH-exposed group, while administrators and security personnel (n=67) served the control. Routine semen parameters (concentration, motility, vitality, and morphology) were analyzed simultaneously; the assessment of sperm DNA integrity endpoints included DNA fragmentation, bulky DNA adducts, and 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxo-dGuo). The degree of sperm DNA fragmentation was measured using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay and sperm chromatin structure assay (SCSA). The PAH-exposed group had a significant increase in bulky DNA adducts and 8-oxo-dGuo compared to the control subjects (Ps = 0.002 and 0.045, respectively). Coke oven workers' percentages of DNA fragmentation and denaturation from the PAH-exposed group were not significantly different from those of the control subjects (Ps = 0.232 and 0.245, respectively). Routine semen parameters and DNA integrity endpoints were not correlated. Concentrations of 8-oxo-dGuo were positively correlated with percentages of DNA fragmentation measured by both TUNEL and SCSA (Ps = 0.045 and 0.034, respectively). However, the concentrations of 8-oxo-dGuo and percentages of DNA fragmentation did not correlate with concentrations of bulky DNA adducts. In summary, coke oven workers with chronic exposure to PAHs experienced decreased sperm DNA integrity. Oxidative stress could contribute to the degree of DNA fragmentation. Bulky DNA adducts may be independent of the formation of DNA fragmentation and oxidative adducts in sperm. Monitoring sperm DNA integrity is recommended as a part of the process of assessing the impact of occupational and environmental toxins on

Sequence and Structure Dependent DNA-DNA Interactions

NASA Astrophysics Data System (ADS)

Kopchick, Benjamin; Qiu, Xiangyun

Molecular forces between dsDNA strands are largely dominated by electrostatics and have been extensively studied. Quantitative knowledge has been accumulated on how DNA-DNA interactions are modulated by varied biological constituents such as ions, cationic ligands, and proteins. Despite its central role in biology, the sequence of DNA has not received substantial attention and ``random'' DNA sequences are typically used in biophysical studies. However, ~50% of human genome is composed of non-random-sequence DNAs, particularly repetitive sequences. Furthermore, covalent modifications of DNA such as methylation play key roles in gene functions. Such DNAs with specific sequences or modifications often take on structures other than the canonical B-form. Here we present series of quantitative measurements of the DNA-DNA forces with the osmotic stress method on different DNA sequences, from short repeats to the most frequent sequences in genome, and to modifications such as bromination and methylation. We observe peculiar behaviors that appear to be strongly correlated with the incurred structural changes. We speculate the causalities in terms of the differences in hydration shell and DNA surface structures.

Rapid identification of 11 human intestinal Lactobacillus species by multiplex PCR assays using group- and species-specific primers derived from the 16S-23S rRNA intergenic spacer region and its flanking 23S rRNA.

PubMed

Song, Y; Kato, N; Liu, C; Matsumiya, Y; Kato, H; Watanabe, K

2000-06-15

Rapid and reliable two-step multiplex polymerase chain reaction (PCR) assays were established to identify human intestinal lactobacilli; a multiplex PCR was used for grouping of lactobacilli with a mixture of group-specific primers followed by four multiplex PCR assays with four sorts of species-specific primer mixtures for identification at the species level. Primers used were designed from nucleotide sequences of the 16S-23S rRNA intergenic spacer region and its flanking 23S rRNA gene of members of the genus Lactobacillus which are commonly isolated from human stool specimens: Lactobacillus acidophilus, Lactobacillus crispatus, Lactobacillus delbrueckii (ssp. bulgaricus and ssp. lactis), Lactobacillus fermentum, Lactobacillus gasseri, Lactobacillus jensenii, Lactobacillus paracasei (ssp. paracasei and ssp. tolerans), Lactobacillus plantarum, Lactobacillus reuteri, Lactobacillus rhamnosus and Lactobacillus salivarius (ssp. salicinius and ssp. salivarius). The established two-step multiplex PCR assays were applied to the identification of 84 Lactobacillus strains isolated from human stool specimens and the PCR results were consistent with the results from the DNA-DNA hybridization assay. These results suggest that the multiplex PCR system established in this study is a simple, rapid and reliable method for the identification of common Lactobacillus isolates from human stool samples.

Investigating Colonization of the Healthy Adult Gastrointestinal Tract by Fungi

PubMed Central

Fofanova, Tatiana Y.; Stewart, Christopher J.; Nash, Andrea K.; Wong, Matthew C.; Gesell, Jonathan R.; Auchtung, Jennifer M.; Ajami, Nadim J.; Petrosino, Joseph F.

2018-01-01

ABSTRACT A wide diversity of fungi have been detected in the human gastrointestinal (GI) tract with the potential to provide or influence important functions. However, many of the fungi most commonly detected in stool samples are also present in food or the oral cavity. Therefore, to recognize which gut fungi are likely to have a sustained influence on human health, there is a need to separate transient members of the GI tract from true colonizers. To identify colonizing fungi, the eukaryotic rRNA operon’s second internal transcribed spacer (ITS2) was sequenced from the stool, saliva, and food of healthy adults following consumption of different controlled diets. Unlike most bacterial 16S rRNA genes, the only fungal ITS2 operational taxonomic units (OTUs) detected in stool DNA across multiple diets were also present in saliva and/or food. Additional analyses, including culture-based approaches and sequencing of the 18S rRNA gene, ITS2 cDNA, and DNA extracted using alternative methods, failed to detect additional fungi. Two abundant fungi, Saccharomyces cerevisiae and Candida albicans, were examined further in healthy volunteers. Saccharomyces became undetectable in stool when a S. cerevisiae-free diet was consumed, and the levels of C. albicans in stool were dramatically reduced by more frequent cleaning of teeth. Extremely low fungal abundance, the inability of fungi to grow under conditions mimicking the distal gut, and evidence from analysis of other public datasets further support the hypothesis that fungi do not routinely colonize the GI tracts of healthy adults. IMPORTANCE We sought to identify the fungi that colonize healthy GI tracts and that have a sustained influence on the diverse functions of the gut microbiome. Instead, we found that all fungi in the stool of healthy volunteers could be explained by their presence in oral and dietary sources and that our results, together with those from other analyses, support the model that there is little or no

Investigating Colonization of the Healthy Adult Gastrointestinal Tract by Fungi.

PubMed

Auchtung, Thomas A; Fofanova, Tatiana Y; Stewart, Christopher J; Nash, Andrea K; Wong, Matthew C; Gesell, Jonathan R; Auchtung, Jennifer M; Ajami, Nadim J; Petrosino, Joseph F

2018-01-01

A wide diversity of fungi have been detected in the human gastrointestinal (GI) tract with the potential to provide or influence important functions. However, many of the fungi most commonly detected in stool samples are also present in food or the oral cavity. Therefore, to recognize which gut fungi are likely to have a sustained influence on human health, there is a need to separate transient members of the GI tract from true colonizers. To identify colonizing fungi, the eukaryotic rRNA operon's second internal transcribed spacer (ITS2) was sequenced from the stool, saliva, and food of healthy adults following consumption of different controlled diets. Unlike most bacterial 16S rRNA genes, the only fungal ITS2 operational taxonomic units (OTUs) detected in stool DNA across multiple diets were also present in saliva and/or food. Additional analyses, including culture-based approaches and sequencing of the 18S rRNA gene, ITS2 cDNA, and DNA extracted using alternative methods, failed to detect additional fungi. Two abundant fungi, Saccharomyces cerevisiae and Candida albicans, were examined further in healthy volunteers. Saccharomyces became undetectable in stool when a S. cerevisiae-free diet was consumed, and the levels of C. albicans in stool were dramatically reduced by more frequent cleaning of teeth. Extremely low fungal abundance, the inability of fungi to grow under conditions mimicking the distal gut, and evidence from analysis of other public datasets further support the hypothesis that fungi do not routinely colonize the GI tracts of healthy adults. IMPORTANCE We sought to identify the fungi that colonize healthy GI tracts and that have a sustained influence on the diverse functions of the gut microbiome. Instead, we found that all fungi in the stool of healthy volunteers could be explained by their presence in oral and dietary sources and that our results, together with those from other analyses, support the model that there is little or no

A field survey using LAMP assay for detection of Schistosoma mansoni in a low-transmission area of schistosomiasis in Umbuzeiro, Brazil: Assessment in human and snail samples.

PubMed

Gandasegui, Javier; Fernández-Soto, Pedro; Muro, Antonio; Simões Barbosa, Constança; Lopes de Melo, Fabio; Loyo, Rodrigo; de Souza Gomes, Elainne Christine

2018-03-01

In Brazil, schistosomiasis is a parasitic disease of public health relevance, mainly in poor areas where Schistosoma mansoni is the only human species encountered and Biomphalaria straminea is one of the intermediate host snails. A nested-PCR based on a specific mitochondrial S. mansoni minisatellite DNA region has been successfully developed and applied as a reference method in Brazil for S. mansoni detection, mainly in host snails for epidemiological studies. The amplification efficiency of LAMP is known to be higher than PCR. The present work aimed to assess the utility of our previously described SmMIT-LAMP assay for S. mansoni detection in human stool and snail samples in a low-transmission area of schistosomiasis in the municipality of Umbuzeiro, Paraíba State, Northeast Region of Brazil. A total of 427 human stool samples were collected during June-July 2016 in the municipality of Umbuzeiro and an overall prevalence of 3.04% (13/427) resulted positive by duplicate Kato-Katz thick smear. A total of 1,175 snails identified as Biomphalaria straminea were collected from 14 breeding sites along the Paraíba riverbank and distributed in 46 pools. DNA from human stool samples and pooled snails was extracted using the phenol/chloroform method. When performing the SmMIT-LAMP assay a total of 49/162 (30.24%) stool samples resulted positive, including 12/13 (92.31%) that were Kato-Katz positive and 37/149 (24.83%) previously Kato-Katz negative. By nested-PCR, only 1/46 pooled DNA snail samples was positive. By SmMIT-LAMP assay, the same sample also resulted positive and an additional one was positive from a different breeding site. Data of human and snail surveys were used to build risk maps of schistosomiasis incidence using kernel density analysis. This is the first study in which a LAMP assay was evaluated in both human stool and snail samples from a low-transmission schistosomiasis-endemic area. Our SmMIT-LAMP proved to be much more efficient in detection of S

Fecal Fat Analyses in Chronic Pancreatitis Importance of Fat Ingestion before Stool Collection

PubMed Central

Engjom, Trond; Jurmy, Palwasha; Tjora, Erling; Gilja, Odd Helge; Dimcevski, Georg

2017-01-01

Objective Quantitative determination of fecal fat still is the gold standard for measuring malabsorption. We evaluated the importance of standardized food intake before and under the collection of feces. Material and Methods In a project, evaluating patients with suspected chronic pancreatitis (CP) and healthy volunteers (HC), stools were collected for 72 hours coupled to registration of nutritional intake over five consecutive days. Patient groups were created by a modified Layer score, which includes imaging findings, clinical parameters and pancreas function testing. Results We found 12 patients with CP, 11 patients without CP and 13 healthy individuals in our database. Median fecal fat in CP patients was 12 g/day, in non-CP patients 5 g/day and in healthy controls 5 g/day. Median fat absorption coefficient was 81% in those with chronic pancreatitis, 92% in those without CP and 92% in healthy controls. Corresponding median fat intake was 65 g/day, 68 g/day and 81 g/day in the respective groups. Spearman Rank Order Correlation between fecal fat (g/d) and fat absorption coefficient in all study subjects (n = 36) was good (-0.88 (p<0.001)). When we stratified groups according to fat intake, correlation between fecal fat and fat absorption was also good (-0.86 to -0.95). Conclusion In the diagnoses of fat malabsorption, calculating the ratio of fat absorption did not give additional information compared to fecal fat. PMID:28095460

The Human DNA glycosylases NEIL1 and NEIL3 Excise Psoralen-Induced DNA-DNA Cross-Links in a Four-Stranded DNA Structure.

PubMed

Martin, Peter R; Couvé, Sophie; Zutterling, Caroline; Albelazi, Mustafa S; Groisman, Regina; Matkarimov, Bakhyt T; Parsons, Jason L; Elder, Rhoderick H; Saparbaev, Murat K

2017-12-12

Interstrand cross-links (ICLs) are highly cytotoxic DNA lesions that block DNA replication and transcription by preventing strand separation. Previously, we demonstrated that the bacterial and human DNA glycosylases Nei and NEIL1 excise unhooked psoralen-derived ICLs in three-stranded DNA via hydrolysis of the glycosidic bond between the crosslinked base and deoxyribose sugar. Furthermore, NEIL3 from Xenopus laevis has been shown to cleave psoralen- and abasic site-induced ICLs in Xenopus egg extracts. Here we report that human NEIL3 cleaves psoralen-induced DNA-DNA cross-links in three-stranded and four-stranded DNA substrates to generate unhooked DNA fragments containing either an abasic site or a psoralen-thymine monoadduct. Furthermore, while Nei and NEIL1 also cleave a psoralen-induced four-stranded DNA substrate to generate two unhooked DNA duplexes with a nick, NEIL3 targets both DNA strands in the ICL without generating single-strand breaks. The DNA substrate specificities of these Nei-like enzymes imply the occurrence of long uninterrupted three- and four-stranded crosslinked DNA-DNA structures that may originate in vivo from DNA replication fork bypass of an ICL. In conclusion, the Nei-like DNA glycosylases unhook psoralen-derived ICLs in various DNA structures via a genuine repair mechanism in which complex DNA lesions can be removed without generation of highly toxic double-strand breaks.

DNA replication stress restricts ribosomal DNA copy number

PubMed Central

Salim, Devika; Bradford, William D.; Freeland, Amy; Cady, Gillian; Wang, Jianmin

2017-01-01

Ribosomal RNAs (rRNAs) in budding yeast are encoded by ~100–200 repeats of a 9.1kb sequence arranged in tandem on chromosome XII, the ribosomal DNA (rDNA) locus. Copy number of rDNA repeat units in eukaryotic cells is maintained far in excess of the requirement for ribosome biogenesis. Despite the importance of the repeats for both ribosomal and non-ribosomal functions, it is currently not known how “normal” copy number is determined or maintained. To identify essential genes involved in the maintenance of rDNA copy number, we developed a droplet digital PCR based assay to measure rDNA copy number in yeast and used it to screen a yeast conditional temperature-sensitive mutant collection of essential genes. Our screen revealed that low rDNA copy number is associated with compromised DNA replication. Further, subculturing yeast under two separate conditions of DNA replication stress selected for a contraction of the rDNA array independent of the replication fork blocking protein, Fob1. Interestingly, cells with a contracted array grew better than their counterparts with normal copy number under conditions of DNA replication stress. Our data indicate that DNA replication stresses select for a smaller rDNA array. We speculate that this liberates scarce replication factors for use by the rest of the genome, which in turn helps cells complete DNA replication and continue to propagate. Interestingly, tumors from mini chromosome maintenance 2 (MCM2)-deficient mice also show a loss of rDNA repeats. Our data suggest that a reduction in rDNA copy number may indicate a history of DNA replication stress, and that rDNA array size could serve as a diagnostic marker for replication stress. Taken together, these data begin to suggest the selective pressures that combine to yield a “normal” rDNA copy number. PMID:28915237

DNA replication stress restricts ribosomal DNA copy number.

PubMed

Salim, Devika; Bradford, William D; Freeland, Amy; Cady, Gillian; Wang, Jianmin; Pruitt, Steven C; Gerton, Jennifer L

2017-09-01

Ribosomal RNAs (rRNAs) in budding yeast are encoded by ~100-200 repeats of a 9.1kb sequence arranged in tandem on chromosome XII, the ribosomal DNA (rDNA) locus. Copy number of rDNA repeat units in eukaryotic cells is maintained far in excess of the requirement for ribosome biogenesis. Despite the importance of the repeats for both ribosomal and non-ribosomal functions, it is currently not known how "normal" copy number is determined or maintained. To identify essential genes involved in the maintenance of rDNA copy number, we developed a droplet digital PCR based assay to measure rDNA copy number in yeast and used it to screen a yeast conditional temperature-sensitive mutant collection of essential genes. Our screen revealed that low rDNA copy number is associated with compromised DNA replication. Further, subculturing yeast under two separate conditions of DNA replication stress selected for a contraction of the rDNA array independent of the replication fork blocking protein, Fob1. Interestingly, cells with a contracted array grew better than their counterparts with normal copy number under conditions of DNA replication stress. Our data indicate that DNA replication stresses select for a smaller rDNA array. We speculate that this liberates scarce replication factors for use by the rest of the genome, which in turn helps cells complete DNA replication and continue to propagate. Interestingly, tumors from mini chromosome maintenance 2 (MCM2)-deficient mice also show a loss of rDNA repeats. Our data suggest that a reduction in rDNA copy number may indicate a history of DNA replication stress, and that rDNA array size could serve as a diagnostic marker for replication stress. Taken together, these data begin to suggest the selective pressures that combine to yield a "normal" rDNA copy number.

Shedding of porcine circovirus type 1 DNA and rotavirus RNA by infants vaccinated with Rotarix®.

PubMed

Mijatovic-Rustempasic, Slavica; Immergluck, Lilly Cheng; Parker, Trisha Chan; Laghaie, Elham; Mohammed, Anaam; McFadden, Terri; Parashar, Umesh D; Bowen, Michael D; Cortese, Margaret M

2017-04-03

Thirty-three infants aged ∼2 months had serial stool samples collected after receipt of Rotarix® vaccine dose 1, and were assessed for shedding of porcine circovirus type 1 DNA and Rotavirus group A RNA by molecular methods. We did not find strong evidence that porcine circovirus type 1 replication occurred. Porcine circovirus type 1 genome with the same sequence as that in Rotarix® was detected in a few infants as late as day ≥ 13; while this timing could suggest there may have been replication and not just transient passage through the gastrointestinal tract, the lack of increase in copy number in any infant supports transient passage and there are inherent limitations to the results. We found that 21% of infants did not shed Rotarix® RVA RNA beyond the day 3 sample, which may suggest lack of vaccine virus replication. Of the infants in whom Rotarix RVA RNA shedding continued, peak copy numbers were reached on days 3-5 for ∼40%, and after day 5 in ∼60%, and shedding can be prolonged (≥ 45 days).

DNA Origami-Graphene Hybrid Nanopore for DNA Detection.

PubMed

Barati Farimani, Amir; Dibaeinia, Payam; Aluru, Narayana R

2017-01-11

DNA origami nanostructures can be used to functionalize solid-state nanopores for single molecule studies. In this study, we characterized a nanopore in a DNA origami-graphene heterostructure for DNA detection. The DNA origami nanopore is functionalized with a specific nucleotide type at the edge of the pore. Using extensive molecular dynamics (MD) simulations, we computed and analyzed the ionic conductivity of nanopores in heterostructures carpeted with one or two layers of DNA origami on graphene. We demonstrate that a nanopore in DNA origami-graphene gives rise to distinguishable dwell times for the four DNA base types, whereas for a nanopore in bare graphene, the dwell time is almost the same for all types of bases. The specific interactions (hydrogen bonds) between DNA origami and the translocating DNA strand yield different residence times and ionic currents. We also conclude that the speed of DNA translocation decreases due to the friction between the dangling bases at the pore mouth and the sequencing DNA strands.

B-DNA to Z-DNA structural transitions in the SV40 enhancer: stabilization of Z-DNA in negatively supercoiled DNA minicircles

NASA Technical Reports Server (NTRS)

Gruskin, E. A.; Rich, A.

1993-01-01

During replication and transcription, the SV40 control region is subjected to significant levels of DNA unwinding. There are three, alternating purine-pyrimidine tracts within this region that can adopt the Z-DNA conformation in response to negative superhelix density: a single copy of ACACACAT and two copies of ATGCATGC. Since the control region is essential for both efficient transcription and replication, B-DNA to Z-DNA transitions in these vital sequence tracts may have significant biological consequences. We have synthesized DNA minicircles to detect B-DNA to Z-DNA transitions in the SV40 enhancer, and to determine the negative superhelix density required to stabilize the Z-DNA. A variety of DNA sequences, including the entire SV40 enhancer and the two segments of the enhancer with alternating purine-pyrimidine tracts, were incorporated into topologically relaxed minicircles. Negative supercoils were generated, and the resulting topoisomers were resolved by electrophoresis. Using an anti-Z-DNA Fab and an electrophoretic mobility shift assay, Z-DNA was detected in the enhancer-containing minicircles at a superhelix density of -0.05. Fab saturation binding experiments demonstrated that three, independent Z-DNA tracts were stabilized in the supercoiled minicircles. Two other minicircles, each with one of the two alternating purine-pyrimidine tracts, also contained single Z-DNA sites. These results confirm the identities of the Z-DNA-forming sequences within the control region. Moreover, the B-DNA to Z-DNA transitions were detected at superhelix densities observed during normal replication and transcription processes in the SV40 life cycle.

DNA book.

PubMed

Kawai, Jun; Hayashizaki, Yoshihide

2003-06-01

We propose herein a new method of DNA distribution, whereby DNA clones or PCR products are printed directly onto the pages of books and delivered to users along with relevant scientific information. DNA sheets, comprising water-soluble paper onto which DNA is spotted, can be bound into books. Readers can easily extract the DNA fragments from DNA sheets and amplify them using PCR. We show that DNA sheets can withstand various conditions that may be experienced during bookbinding and delivery, such as high temperatures and humidity. Almost all genes (95%-100% of randomly selected RIKEN mouse cDNA clones) were recovered successfully by use of PCR. Readers can start their experiments after a 2-h PCR amplification without waiting for the delivery of DNA clones. The DNA Book thus provides a novel method for delivering DNA in a timely and cost-effective manner. A sample DNA sheet (carrying RIKEN mouse cDNA clones encoding genes of enzymes for the TCA cycle) is included in this issue for field-testing. We would greatly appreciate it if readers could attempt to extract DNA and report the results and whether the DNA sheet was shipped to readers in good condition.

Colorectal Cancer Screening

MedlinePlus

... blood test Sigmoidoscopy Colonoscopy Virtual colonoscopy DNA stool test Studies have shown that screening for colorectal cancer using ... decrease the risk of dying from cancer. Scientists study screening tests to find those with the fewest risks and ...

Risks of Colorectal Cancer Screening

MedlinePlus

... blood test Sigmoidoscopy Colonoscopy Virtual colonoscopy DNA stool test Studies have shown that screening for colorectal cancer using ... decrease the risk of dying from cancer. Scientists study screening tests to find those with the fewest risks and ...

Molecular Detection of Eukaryotes in a Single Human Stool Sample from Senegal

PubMed Central

Hamad, Ibrahim; Sokhna, Cheikh; Raoult, Didier; Bittar, Fadi

2012-01-01

Background Microbial eukaryotes represent an important component of the human gut microbiome, with different beneficial or harmful roles; some species are commensal or mutualistic, whereas others are opportunistic or parasitic. The diversity of eukaryotes inhabiting humans remains relatively unexplored because of either the low abundance of these organisms in human gut or because they have received limited attention from a whole-community perspective. Methodology/Principal Finding In this study, a single fecal sample from a healthy African male was studied using both culture-dependent methods and extended molecular methods targeting the 18S rRNA and ITS sequences. Our results revealed that very few fungi, including Candida spp., Galactomyces spp., and Trichosporon asahii, could be isolated using culture-based methods. In contrast, a relatively a high number of eukaryotic species could be identified in this fecal sample when culture-independent methods based on various primer sets were used. A total of 27 species from one sample were found among the 977 analyzed clones. The clone libraries were dominated by fungi (716 clones/977, 73.3%), corresponding to 16 different species. In addition, 187 sequences out of 977 (19.2%) corresponded to 9 different species of plants; 59 sequences (6%) belonged to other micro-eukaryotes in the gut, including Entamoeba hartmanni and Blastocystis sp; and only 15 clones/977 (1.5%) were related to human 18S rRNA sequences. Conclusion Our results revealed a complex eukaryotic community in the volunteer’s gut, with fungi being the most abundant species in the stool sample. Larger investigations are needed to assess the generality of these results and to understand their roles in human health and disease. PMID:22808282

DNA Clutch Probes for Circulating Tumor DNA Analysis.

PubMed

Das, Jagotamoy; Ivanov, Ivaylo; Sargent, Edward H; Kelley, Shana O

2016-08-31

Progress toward the development of minimally invasive liquid biopsies of disease is being bolstered by breakthroughs in the analysis of circulating tumor DNA (ctDNA): DNA released from cancer cells into the bloodstream. However, robust, sensitive, and specific methods of detecting this emerging analyte are lacking. ctDNA analysis has unique challenges, since it is imperative to distinguish circulating DNA from normal cells vs mutation-bearing sequences originating from tumors. Here we report the electrochemical detection of mutated ctDNA in samples collected from cancer patients. By developing a strategy relying on the use of DNA clutch probes (DCPs) that render specific sequences of ctDNA accessible, we were able to readout the presence of mutated ctDNA. DCPs prevent reassociation of denatured DNA strands: they make one of the two strands of a dsDNA accessible for hybridization to a probe, and they also deactivate other closely related sequences in solution. DCPs ensure thereby that only mutated sequences associate with chip-based sensors detecting hybridization events. The assay exhibits excellent sensitivity and specificity in the detection of mutated ctDNA: it detects 1 fg/μL of a target mutation in the presence of 100 pg/μL of wild-type DNA, corresponding to detecting mutations at a level of 0.01% relative to wild type. This approach allows accurate analysis of samples collected from lung cancer and melanoma patients. This work represents the first detection of ctDNA without enzymatic amplification.

DNA Book

PubMed Central

Kawai, Jun; Hayashizaki, Yoshihide

2003-01-01

We propose herein a new method of DNA distribution, whereby DNA clones or PCR products are printed directly onto the pages of books and delivered to users along with relevant scientific information. DNA sheets, comprising water-soluble paper onto which DNA is spotted, can be bound into books. Readers can easily extract the DNA fragments from DNA sheets and amplify them using PCR. We show that DNA sheets can withstand various conditions that may be experienced during bookbinding and delivery, such as high temperatures and humidity. Almost all genes (95%–100% of randomly selected RIKEN mouse cDNA clones) were recovered successfully by use of PCR. Readers can start their experiments after a 2-h PCR amplification without waiting for the delivery of DNA clones. The DNA Book thus provides a novel method for delivering DNA in a timely and cost-effective manner. A sample DNA sheet (carrying RIKEN mouse cDNA clones encoding genes of enzymes for the TCA cycle) is included in this issue for field-testing. We would greatly appreciate it if readers could attempt to extract DNA and report the results and whether the DNA sheet was shipped to readers in good condition. PMID:12819147

Multivalent Lipid--DNA Complexes: Distinct DNA Compaction Regimes

NASA Astrophysics Data System (ADS)

Evans, Heather M.; Ahmad, A.; Ewert, K.; Safinya, C. R.

2004-03-01

Cationic liposomes (CL), while intrinsically advantageous in comparison to viruses, still have limited success for gene therapy and require more study. CL spontaneously self-assemble with DNA via counterion release, forming small particles approximately 200nm in diameter. X-ray diffraction reveals CL-DNA structures that are typically a multilamellar organization of lipids with DNA intercalated between the layers. We explore the structural properties of CL-DNA complexes formed with new multivalent lipids (Ewert et al, J. Med. Chem. 2002; 45:5023) that range from 2+ to 16+. Contrary to a simple prediction for the DNA interaxial spacing d_DNA based on a geometrical space-filling model, these lipids show dramatic DNA compaction, down to d_DNA ˜ 25 ÅVariations in the membrane charge density, σ _M, lead to distinct spacing regimes. We propose that this DNA condensation is controlled by a unique locking mechanism between the DNA double helix and the large, multivalent lipid head groups. Funded by NSF DMR-0203755 and NIH GM-59288.

DNA Damage, DNA Repair, Aging, and Neurodegeneration

PubMed Central

Maynard, Scott; Fang, Evandro Fei; Scheibye-Knudsen, Morten; Croteau, Deborah L.; Bohr, Vilhelm A.

2015-01-01

Aging in mammals is accompanied by a progressive atrophy of tissues and organs, and stochastic damage accumulation to the macromolecules DNA, RNA, proteins, and lipids. The sequence of the human genome represents our genetic blueprint, and accumulating evidence suggests that loss of genomic maintenance may causally contribute to aging. Distinct evidence for a role of imperfect DNA repair in aging is that several premature aging syndromes have underlying genetic DNA repair defects. Accumulation of DNA damage may be particularly prevalent in the central nervous system owing to the low DNA repair capacity in postmitotic brain tissue. It is generally believed that the cumulative effects of the deleterious changes that occur in aging, mostly after the reproductive phase, contribute to species-specific rates of aging. In addition to nuclear DNA damage contributions to aging, there is also abundant evidence for a causative link between mitochondrial DNA damage and the major phenotypes associated with aging. Understanding the mechanistic basis for the association of DNA damage and DNA repair with aging and age-related diseases, such as neurodegeneration, would give insight into contravening age-related diseases and promoting a healthy life span. PMID:26385091

Colorectal Cancer Screening (PDQ®)—Patient Version

Cancer.gov

There are five types of tests that are used to screen for colorectal cancer: fecal occult blood test, sigmoidoscopy, colonoscopy, virtual colonoscopy, and DNA stool test. Learn more about these and other tests in this expert-reviewed summary.

Exposure of DNA bases induced by the interaction of DNA and calf thymus DNA helix-destabilizing protein.

PubMed Central

Kohwi-Shigematsu, T; Enomoto, T; Yamada, M A; Nakanishi, M; Tsuboi, M

1978-01-01

The reaction of chloroacetaldehyde with adenine bases in DNA to give a fluorescent product was used to study the availability to intermolecular reaction of positions 1 and 6 of adenine in DNA complexes with calf thymus DNA helix-destabilizing protein. No inhibition of this reaction was observed when heat-denatured DNA was complexed with the protein at a protein/DNA weight ratio of 10:1, compared to free DNA. On the contrary, the same reaction was inhibited markedly for denatured DNA in the presence of calf thymus histone HI at protein/DNA weight ratio of 2:1. Furthermore, the exchange rate for hydrogens of amino and imide groups of DNA bases in DNA strands with deuterium in the solvent was totally unaffected upon complexing of DNA with the DNA helix-destabilizing protein as examined by stopped-flow ultraviolet spectroscopy. These results indicate that the DNA helix-destabilizing protein forms a complex with single-stranded DNA, leaving DNA bases uncovered by the protein. The fluorescence intensity of DNA pretreated with chloroacetaldehyde was amplified by nearly 3-fold upon addition of the DNA helix-destabilizing protein. The possibility of "unstacking" of DNA bases induced by the protein is discussed. PMID:216994

Genetic Biomarker Prevalence Is Similar in Fecal Immunochemical Test Positive and Negative Colorectal Cancer Tissue.

PubMed

Levin, Theodore R; Corley, Douglas A; Jensen, Christopher D; Marks, Amy R; Zhao, Wei K; Zebrowski, Alexis M; Quinn, Virginia P; Browne, Lawrence W; Taylor, William R; Ahlquist, David A; Lidgard, Graham P; Berger, Barry M

2017-03-01

Fecal immunochemical test (FIT) screening detects most asymptomatic colorectal cancers. Combining FIT screening with stool-based genetic biomarkers increases sensitivity for cancer, but whether DNA biomarkers (biomarkers) differ for cancers detected versus missed by FIT screening has not been evaluated in a community-based population. To evaluate tissue biomarkers among Kaiser Permanente Northern California patients diagnosed with colorectal cancer within 2 years after FIT screening. FIT-negative and FIT-positive colorectal cancer patients 50-77 years of age were matched on age, sex, and cancer stage. Adequate DNA was isolated from paraffin-embedded specimens in 210 FIT-negative and 211 FIT-positive patients. Quantitative allele-specific real-time target and signal amplification assays were performed for 7 K-ras mutations and 10 aberrantly methylated DNA biomarkers (NDRG4, BMP3, SFMBT2_895, SFMBT2_896, SFMBT2_897, CHST2_7890, PDGFD, VAV3, DTX1, CHST2_7889). One or more biomarkers were found in 414 of 421 CRCs (98.3%). Biomarker expression was not associated with FIT status, with the exception of higher SFMBT2_897 expression in FIT-negative (194 of 210; 92.4%) than in FIT-positive cancers (180 of 211; 85.3%; p = 0.02). There were no consistent differences in biomarker expression by FIT status within age, sex, stage, and cancer location subgroups. The biomarkers of a currently in-use multi-target stool DNA test (K-ras, NDRG4, and BMP3) and eight newly characterized methylated biomarkers were commonly expressed in tumor tissue specimens, independent of FIT result. Additional study using stool-based testing with these new biomarkers will allow assessment of sensitivity, specificity, and clinical utility.

DNA encoding a DNA repair protein

DOEpatents

Petrini, John H.; Morgan, William Francis; Maser, Richard Scott; Carney, James Patrick

2006-08-15

An isolated and purified DNA molecule encoding a DNA repair protein, p95, is provided, as is isolated and purified p95. Also provided are methods of detecting p95 and DNA encoding p95. The invention further provides p95 knock-out mice.

Loss of maintenance DNA methylation results in abnormal DNA origin firing during DNA replication

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haruta, Mayumi; Shimada, Midori, E-mail: midorism@med.nagoya-cu.ac.jp; Nishiyama, Atsuya

The mammalian maintenance methyltransferase DNMT1 [DNA (cytosine-5-)-methyltransferase 1] mediates the inheritance of the DNA methylation pattern during replication. Previous studies have shown that depletion of DNMT1 causes a severe growth defect and apoptosis in differentiated cells. However, the detailed mechanisms behind this phenomenon remain poorly understood. Here we show that conditional ablation of Dnmt1 in murine embryonic fibroblasts (MEFs) resulted in an aberrant DNA replication program showing an accumulation of late-S phase replication and causing severely defective growth. Furthermore, we found that the catalytic activity and replication focus targeting sequence of DNMT1 are required for a proper DNA replication program.more » Taken together, our findings suggest that the maintenance of DNA methylation by DNMT1 plays a critical role in proper regulation of DNA replication in mammalian cells. - Highlights: • DNMT1 depletion results in an abnormal DNA replication program. • Aberrant DNA replication is independent of the DNA damage checkpoint in DNMT1cKO. • DNMT1 catalytic activity and RFT domain are required for proper DNA replication. • DNMT1 catalytic activity and RFT domain are required for cell proliferation.« less

DNA stable-isotope probing (DNA-SIP).

PubMed

Dunford, Eric A; Neufeld, Josh D

2010-08-02

DNA stable-isotope probing (DNA-SIP) is a powerful technique for identifying active microorganisms that assimilate particular carbon substrates and nutrients into cellular biomass. As such, this cultivation-independent technique has been an important methodology for assigning metabolic function to the diverse communities inhabiting a wide range of terrestrial and aquatic environments. Following the incubation of an environmental sample with stable-isotope labelled compounds, extracted nucleic acid is subjected to density gradient ultracentrifugation and subsequent gradient fractionation to separate nucleic acids of differing densities. Purification of DNA from cesium chloride retrieves labelled and unlabelled DNA for subsequent molecular characterization (e.g. fingerprinting, microarrays, clone libraries, metagenomics). This JoVE video protocol provides visual step-by-step explanations of the protocol for density gradient ultracentrifugation, gradient fractionation and recovery of labelled DNA. The protocol also includes sample SIP data and highlights important tips and cautions that must be considered to ensure a successful DNA-SIP analysis.

Fluorescence studies with DNA probes: dynamic aspects of DNA structure and DNA-protein interactions

NASA Astrophysics Data System (ADS)

Millar, David P.; Carver, Theodore E.

1994-08-01

Time-resolved fluorescence measurements of optical probes incorporated at specific sites in DNA provides a new approach to studies of DNA structure and DNA:protein interactions. This approach can be used to study complex multi-state behavior, such as the folding of DNA into alternative higher order structures or the transfer of DNA between multiple binding sites on a protein. In this study, fluorescence anisotropy decay of an internal dansyl probe attached to 17/27-mer oligonucleotides was used to monitor the distribution of DNA 3' termini bound at either the polymerase of 3' to 5' exonuclease sites of the Klenow fragment of DNA polymerase I. Partitioning of the primer terminus between the two active sites of the enzyme resulted in a heterogeneous probe environment, reflected in the associative behavior of the fluorescence anisotropy decay. Analysis of the anisotropy decay with a two state model of solvent-exposed and protein-associated dansyl probes was used to determine the fraction of DNA bound at each site. We examined complexes of Klenow fragment with DNAs containing various base mismatches. Single mismatches at the primer terminus caused a 3-fold increase in the equilibrium partitioning of DNA into the exonuclease site, while two or more consecutive G:G mismatches caused the DNA to bind exclusively at the exonuclease site, with a partitioning constant at least 250- fold greater than that of the corresponding matched DNA sequence. Internal single mismatches located up to four bases from the primer terminus produced larger effects than the same mismatch at the primer terminus. These results provide insight into the recognition mechanisms that enable DNA polymerases to proofread misincorporated bases during DNA replication.

The Dynamic Interplay Between DNA Topoisomerases and DNA Topology.

PubMed

Seol, Yeonee; Neuman, Keir C

2016-09-01

Topological properties of DNA influence its structure and biochemical interactions. Within the cell DNA topology is constantly in flux. Transcription and other essential processes including DNA replication and repair, alter the topology of the genome, while introducing additional complications associated with DNA knotting and catenation. These topological perturbations are counteracted by the action of topoisomerases, a specialized class of highly conserved and essential enzymes that actively regulate the topological state of the genome. This dynamic interplay among DNA topology, DNA processing enzymes, and DNA topoisomerases, is a pervasive factor that influences DNA metabolism in vivo . Building on the extensive structural and biochemical characterization over the past four decades that established the fundamental mechanistic basis of topoisomerase activity, the unique roles played by DNA topology in modulating and influencing the activity of topoisomerases have begun to be explored. In this review we survey established and emerging DNA topology dependent protein-DNA interactions with a focus on in vitro measurements of the dynamic interplay between DNA topology and topoisomerase activity.

The dynamic interplay between DNA topoisomerases and DNA topology.

PubMed

Seol, Yeonee; Neuman, Keir C

2016-11-01

Topological properties of DNA influence its structure and biochemical interactions. Within the cell, DNA topology is constantly in flux. Transcription and other essential processes, including DNA replication and repair, not only alter the topology of the genome but also introduce additional complications associated with DNA knotting and catenation. These topological perturbations are counteracted by the action of topoisomerases, a specialized class of highly conserved and essential enzymes that actively regulate the topological state of the genome. This dynamic interplay among DNA topology, DNA processing enzymes, and DNA topoisomerases is a pervasive factor that influences DNA metabolism in vivo. Building on the extensive structural and biochemical characterization over the past four decades that has established the fundamental mechanistic basis of topoisomerase activity, scientists have begun to explore the unique roles played by DNA topology in modulating and influencing the activity of topoisomerases. In this review we survey established and emerging DNA topology-dependent protein-DNA interactions with a focus on in vitro measurements of the dynamic interplay between DNA topology and topoisomerase activity.

Repulsive DNA-DNA interactions accelerate viral DNA packaging in phage Phi29.

PubMed

Keller, Nicholas; delToro, Damian; Grimes, Shelley; Jardine, Paul J; Smith, Douglas E

2014-06-20

We use optical tweezers to study the effect of attractive versus repulsive DNA-DNA interactions on motor-driven viral packaging. Screening of repulsive interactions accelerates packaging, but induction of attractive interactions by spermidine(3+) causes heterogeneous dynamics. Acceleration is observed in a fraction of complexes, but most exhibit slowing and stalling, suggesting that attractive interactions promote nonequilibrium DNA conformations that impede the motor. Thus, repulsive interactions facilitate packaging despite increasing the energy of the theoretical optimum spooled DNA conformation.

Colorectal Cancer Screening (PDQ®)—Health Professional Version

Cancer.gov

Colorectal cancer (CRC) screening reduces CRC mortality; some screening modalities also reduce CRC incidence. Get detailed information about CRC screening tests (e.g., fecal occult blood test, sigmoidoscopy, colonoscopy, stool DNA) including potential benefits and harms in this clinician summary.

Efficient Sleeping Beauty DNA Transposition From DNA Minicircles

PubMed Central

Sharma, Nynne; Cai, Yujia; Bak, Rasmus O; Jakobsen, Martin R; Schrøder, Lisbeth Dahl; Mikkelsen, Jacob Giehm

2013-01-01

DNA transposon-based vectors have emerged as new potential delivery tools in therapeutic gene transfer. Such vectors are now showing promise in hematopoietic stem cells and primary human T cells, and clinical trials with transposon-engineered cells are on the way. However, the use of plasmid DNA as a carrier of the vector raises safety concerns due to the undesirable administration of bacterial sequences. To optimize vectors based on the Sleeping Beauty (SB) DNA transposon for clinical use, we examine here SB transposition from DNA minicircles (MCs) devoid of the bacterial plasmid backbone. Potent DNA transposition, directed by the hyperactive SB100X transposase, is demonstrated from MC donors, and the stable transfection rate is significantly enhanced by expressing the SB100X transposase from MCs. The stable transfection rate is inversely related to the size of circular donor, suggesting that a MC-based SB transposition system benefits primarily from an increased cellular uptake and/or enhanced expression which can be observed with DNA MCs. DNA transposon and transposase MCs are easily produced, are favorable in size, do not carry irrelevant DNA, and are robust substrates for DNA transposition. In accordance, DNA MCs should become a standard source of DNA transposons not only in therapeutic settings but also in the daily use of the SB system. PMID:23443502

Ketone-DNA: a versatile postsynthetic DNA decoration platform.

PubMed

Dey, S; Sheppard, T L

2001-12-13

[reaction: see text] A general strategy for the functional diversification of DNA oligonucleotides under physiological conditions was developed. We describe the synthesis of DNA molecules bearing ketone ports (ketone-DNA) and the efficient postsynthetic decoration of ketone-DNA with structurally diverse aminooxy compounds.

DNA profiling of trace DNA recovered from bedding.

PubMed

Petricevic, Susan F; Bright, Jo-Anne; Cockerton, Sarah L

2006-05-25

Trace DNA is often detected on handled items and worn clothing examined in forensic laboratories. In this study, the potential transfer of trace DNA to bedding by normal contact, when an individual sleeps in a bed, is examined. Volunteers slept one night on a new, lower bed sheet in their own bed and one night in a bed foreign to them. Samples from the sheets were collected and analysed by DNA profiling. The results indicate that the DNA profile of an individual can be obtained from bedding after one night of sleeping in a bed. The DNA profile of the owner of the bed could also be detected in the foreign bed experiments. Since mixed DNA profiles can be obtained from trace DNA on bedding, caution should be exercised when drawing conclusions from DNA profiling results obtained from such samples. This transfer may have important repercussions in sexual assault investigations.

Diagnostic accuracy and applicability of a PCR system for the detection of Schistosoma mansoni DNA in human urine samples from an endemic area.

PubMed

Enk, Martin Johannes; Oliveira e Silva, Guilherme; Rodrigues, Nilton Barnabé

2012-01-01

Schistosomiasis caused by Schistosoma mansoni, one of the most neglected human parasitoses in Latin America and Africa, is routinely confirmed by microscopic visualization of eggs in stool. The main limitation of this diagnostic approach is its lack of sensitivity in detecting individual low worm burdens and consequently data on infection rates in low transmission settings are little reliable. According to the scientific literature, PCR assays are characterized by high sensitivity and specificity in detecting parasite DNA in biological samples. A simple and cost effective extraction method for DNA of Schistosoma mansoni from urine samples in combination with a conventional PCR assay was developed and applied in an endemic area. This urine based PCR system was tested for diagnostic accuracy among a population of a small village in an endemic area, comparing it to a reference test composed of three different parasitological techniques. The diagnostic parameters revealed a sensitivity of 100%, a specificity of 91.20%, positive and negative predictive values of 86.25% and 100%, respectively, and a test accuracy of 94.33%. Further statistical analysis showed a k index of 0.8806, indicating an excellent agreement between the reference test and the PCR system. Data obtained from the mouse model indicate the infection can be detected one week after cercariae penetration, opening a new perspective for early detection and patient management during this stage of the disease. The data indicate that this innovative PCR system provides a simple to handle and robust diagnostic tool for the detection of S. mansoni DNA from urine samples and a promising approach to overcome the diagnostic obstacles in low transmission settings. Furthermore the principals of this molecular technique, based on the examination of human urine samples may be useful for the diagnosis of other neglected tropical diseases that can be detected by trans-renal DNA.

Identification of and Screening for Human Helicobacter cinaedi Infections and Carriers via Nested PCR

PubMed Central

Oyama, Kohta; Khan, Shahzada; Okamoto, Tatsuya; Fujii, Shigemoto; Ono, Katsuhiko; Matsunaga, Tetsuro; Yoshitake, Jun; Sawa, Tomohiro; Tomida, Junko; Kawamura, Yoshiaki

2012-01-01

Helicobacter cinaedi is the most frequently reported enterohepatic Helicobacter species isolated from humans. Earlier research suggested that certain patients with H. cinaedi infection may remain undiagnosed or incorrectly diagnosed because of difficulties in detecting the bacteria by conventional culture methods. Here, we report a nested PCR assay that rapidly detects the cytolethal distending toxin gene (cdt) of H. cinaedi with high specificity and sensitivity. Specificity of the assay was validated by using different species of Helicobacter and Campylobacter, as well as known H. cinaedi-positive and -negative samples. The sensitivity of detection for the cdt gene in the assay was 102 CFU/ml urine or 102 CFU/105 infected RAW 264.7 cells. In an H. cinaedi-infected mouse model, the cdt gene of H. cinaedi was effectively detected via the assay with urine (6/7), stool (2/3), and blood (2/6) samples. Importantly, it detected H. cinaedi in blood, urine, and stool samples from one patient with a suspected H. cinaedi infection and three patients with known infections. The assay was further used clinically to follow up two H. cinaedi-infected patients after antibiotic treatment. Stool samples from these two patients evaluated by nested PCR after antibiotic therapy showed clearance of bacterial DNA. Finally, analysis of stool specimens from healthy volunteers showed occasional positive reactions (4/30) to H. cinaedi DNA, which suggests intestinal colonization by H. cinaedi in healthy subjects. In conclusion, this nested PCR assay may be useful for the rapid diagnosis, antimicrobial treatment evaluation, and epidemiological study of H. cinaedi infection. PMID:23015666

Human DNA ligase III recognizes DNA ends by dynamic switching between two DNA-bound states.

PubMed

Cotner-Gohara, Elizabeth; Kim, In-Kwon; Hammel, Michal; Tainer, John A; Tomkinson, Alan E; Ellenberger, Tom

2010-07-27

Human DNA ligase III has essential functions in nuclear and mitochondrial DNA replication and repair and contains a PARP-like zinc finger (ZnF) that increases the extent of DNA nick joining and intermolecular DNA ligation, yet the bases for ligase III specificity and structural variation among human ligases are not understood. Here combined crystal structure and small-angle X-ray scattering results reveal dynamic switching between two nick-binding components of ligase III: the ZnF-DNA binding domain (DBD) forms a crescent-shaped surface used for DNA end recognition which switches to a ring formed by the nucleotidyl transferase (NTase) and OB-fold (OBD) domains for catalysis. Structural and mutational analyses indicate that high flexibility and distinct DNA binding domain features in ligase III assist both nick sensing and the transition from nick sensing by the ZnF to nick joining by the catalytic core. The collective results support a "jackknife model" in which the ZnF loads ligase III onto nicked DNA and conformational changes deliver DNA into the active site. This work has implications for the biological specificity of DNA ligases and functions of PARP-like zinc fingers.

Protein Interactions in T7 DNA Replisome Facilitate DNA Damage Bypass.

PubMed

Zou, Zhenyu; Chen, Ze; Xue, Qizhen; Xu, Ying; Xiong, Jingyuan; Yang, Ping; Le, Shuai; Zhang, Huidong

2018-06-14

DNA replisome inevitably encounters DNA damage during DNA replication. T7 DNA replisome contains DNA polymerase (gp5), the processivity factor thioredoxin (trx), helicase-primase (gp4), and ssDNA binding protein (gp2.5). T7 protein interactions mediate this DNA replication. However, whether the protein interactions could promote DNA damage bypass is still little addressed. In this study, we investigated the strand-displacement DNA synthesis past 8-oxoG or O6-MeG at the synthetic DNA fork by T7 DNA replisome. DNA damage does not obviously affect the binding affinities among helicase, polymerase, and DNA fork. Relative to unmodified G, both 8-oxoG and O6-MeG, as well as GC-rich template sequence clusters, inhibit the strand-displacement DNA synthesis and produce partial extension products. Relative to gp4 ΔC-tail, gp4 promotes the DNA damage bypass. The presence of gp2.5 further promotes this bypass. Thus, the interactions of polymerase with helicase and ssDNA binidng protein faciliate the DNA damage bypass. Similarly, accessory proteins in other complicated DNA replisomes also facilitate the DNA damage bypass. This work provides the novel mechanism information of DNA damage bypass by DNA replisome. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DNA translocation by human uracil DNA glycosylase: the case of single-stranded DNA and clustered uracils.

PubMed

Schonhoft, Joseph D; Stivers, James T

2013-04-16

Human uracil DNA glycosylase (hUNG) plays a central role in DNA repair and programmed mutagenesis of Ig genes, requiring it to act on sparsely or densely spaced uracil bases located in a variety of contexts, including U/A and U/G base pairs, and potentially uracils within single-stranded DNA (ssDNA). An interesting question is whether the facilitated search mode of hUNG, which includes both DNA sliding and hopping, changes in these different contexts. Here we find that hUNG uses an enhanced local search mode when it acts on uracils in ssDNA, and also, in a context where uracils are densely clustered in duplex DNA. In the context of ssDNA, hUNG performs an enhanced local search by sliding with a mean sliding length larger than that of double-stranded DNA (dsDNA). In the context of duplex DNA, insertion of high-affinity abasic product sites between two uracil lesions serves to significantly extend the apparent sliding length on dsDNA from 4 to 20 bp and, in some cases, leads to directionally biased 3' → 5' sliding. The presence of intervening abasic product sites mimics the situation where hUNG acts iteratively on densely spaced uracils. The findings suggest that intervening product sites serve to increase the amount of time the enzyme remains associated with DNA as compared to nonspecific DNA, which in turn increases the likelihood of sliding as opposed to falling off the DNA. These findings illustrate how the search mechanism of hUNG is not predetermined but, instead, depends on the context in which the uracils are located.

Abundance of enterovirus C in RD-L20B cell culture-negative stool samples from acute flaccid paralysis cases in Nigeria is geographically defined.

PubMed

Donbraye, Emmanuel; Olasunkanmi, Oluwatayo Israel; Opabode, Babatunde Ayoola; Ishola, Temitayo Rachael; Faleye, Temitope Oluwasegun Cephas; Adewumi, Olubusuyi Moses; Adeniji, Johnson Adekunle

2018-06-01

We recently showed that enteroviruses (EVs) andenterovirus species C (EV-C) in particular were abundant in faecal samples from children who had been diagnosed with acute flaccid paralysis (AFP) in Nigeria but declared to be EV-free by the RD-L20B cell culture-based algorithm. In this study, we investigated whether this observed preponderance of EVs (and EV-Cs) in such samples varies by geographical region. One hundred and eight samples (i.e. 54 paired stool suspensions from 54 AFP cases) that had previously been confirmed to be negative for EVs by the WHO-recommended RD-L20B cell culture-based algorithm were analysed. The 108 samples were made into 54 pools (27 each from North-West and South-South Nigeria). All were subjected to RNA extraction, cDNA synthesis and the WHO-recommended semi-nested PCR assay and its modifications. All of the amplicons were sequenced, and the enteroviruses identified, using the enterovirus genotyping tool and phylogenetic analysis. EVs were detected in 16 (29.63 %) of the 54 samples that were screened and successfully identified in 14 (25.93 %). Of these, 10 were from North-West and 4 were from South-South Nigeria. One (7.14 %), 2 (14.29 %) and 11 (78.57 %) of the strains detected were EV-A, EV-B and EV-C, respectively. The 10 strains from North-West Nigeria included 7 EV types, namely CV-A10, E29, CV-A13, CV-A17, CV-A19, CV-A24 and EV-C99. The four EV types recovered from South-South Nigeria were E31, CV-A1, EV-C99 and EV-C116. The results of this study showed that the presence of EVs and consequently EV-Cs in AFP samples declared to be EV-free by the RD-L20B cell culture-based algorithm varies by geographical region in Nigeria.

An anti-DNA antibody prefers damaged dsDNA over native.

PubMed

Akberova, N I; Zhmurov, A A; Nevzorova, T A; Litvinov, R I

2017-01-01

DNA-protein interactions, including DNA-antibody complexes, have both fundamental and practical significance. In particular, antibodies against double-stranded DNA play an important role in the pathogenesis of autoimmune diseases. Elucidation of structural mechanisms of an antigen recognition and interaction of anti-DNA antibodies provides a basis for understanding the role of DNA-containing immune complexes in human pathologies and for new treatments. Here we used Molecular Dynamic simulations of bimolecular complexes of a segment of dsDNA with a monoclonal anti-DNA antibody's Fab-fragment to obtain detailed structural and physical characteristics of the dynamic intermolecular interactions. Using a computationally modified crystal structure of a Fab-DNA complex (PDB: 3VW3), we studied in silico equilibrium Molecular Dynamics of the Fab-fragment associated with two homologous dsDNA fragments, containing or not containing dimerized thymine, a product of DNA photodamage. The Fab-fragment interactions with the thymine dimer-containing DNA was thermodynamically more stable than with the native DNA. The amino acid residues constituting a paratope and the complementary nucleotide epitopes for both Fab-DNA constructs were identified. Stacking and electrostatic interactions were shown to play the main role in the antibody-dsDNA contacts, while hydrogen bonds were less significant. The aggregate of data show that the chemically modified dsDNA (containing a covalent thymine dimer) has a higher affinity toward the antibody and forms a stronger immune complex. These findings provide a mechanistic insight into formation and properties of the pathogenic anti-DNA antibodies in autoimmune diseases, such as systemic lupus erythematosus, associated with skin photosensibilization and DNA photodamage.

DNA-based watermarks using the DNA-Crypt algorithm.

PubMed

Heider, Dominik; Barnekow, Angelika

2007-05-29

The aim of this paper is to demonstrate the application of watermarks based on DNA sequences to identify the unauthorized use of genetically modified organisms (GMOs) protected by patents. Predicted mutations in the genome can be corrected by the DNA-Crypt program leaving the encrypted information intact. Existing DNA cryptographic and steganographic algorithms use synthetic DNA sequences to store binary information however, although these sequences can be used for authentication, they may change the target DNA sequence when introduced into living organisms. The DNA-Crypt algorithm and image steganography are based on the same watermark-hiding principle, namely using the least significant base in case of DNA-Crypt and the least significant bit in case of the image steganography. It can be combined with binary encryption algorithms like AES, RSA or Blowfish. DNA-Crypt is able to correct mutations in the target DNA with several mutation correction codes such as the Hamming-code or the WDH-code. Mutations which can occur infrequently may destroy the encrypted information, however an integrated fuzzy controller decides on a set of heuristics based on three input dimensions, and recommends whether or not to use a correction code. These three input dimensions are the length of the sequence, the individual mutation rate and the stability over time, which is represented by the number of generations. In silico experiments using the Ypt7 in Saccharomyces cerevisiae shows that the DNA watermarks produced by DNA-Crypt do not alter the translation of mRNA into protein. The program is able to store watermarks in living organisms and can maintain the original information by correcting mutations itself. Pairwise or multiple sequence alignments show that DNA-Crypt produces few mismatches between the sequences similar to all steganographic algorithms.

DNA-based watermarks using the DNA-Crypt algorithm

PubMed Central

Heider, Dominik; Barnekow, Angelika

2007-01-01

Background The aim of this paper is to demonstrate the application of watermarks based on DNA sequences to identify the unauthorized use of genetically modified organisms (GMOs) protected by patents. Predicted mutations in the genome can be corrected by the DNA-Crypt program leaving the encrypted information intact. Existing DNA cryptographic and steganographic algorithms use synthetic DNA sequences to store binary information however, although these sequences can be used for authentication, they may change the target DNA sequence when introduced into living organisms. Results The DNA-Crypt algorithm and image steganography are based on the same watermark-hiding principle, namely using the least significant base in case of DNA-Crypt and the least significant bit in case of the image steganography. It can be combined with binary encryption algorithms like AES, RSA or Blowfish. DNA-Crypt is able to correct mutations in the target DNA with several mutation correction codes such as the Hamming-code or the WDH-code. Mutations which can occur infrequently may destroy the encrypted information, however an integrated fuzzy controller decides on a set of heuristics based on three input dimensions, and recommends whether or not to use a correction code. These three input dimensions are the length of the sequence, the individual mutation rate and the stability over time, which is represented by the number of generations. In silico experiments using the Ypt7 in Saccharomyces cerevisiae shows that the DNA watermarks produced by DNA-Crypt do not alter the translation of mRNA into protein. Conclusion The program is able to store watermarks in living organisms and can maintain the original information by correcting mutations itself. Pairwise or multiple sequence alignments show that DNA-Crypt produces few mismatches between the sequences similar to all steganographic algorithms. PMID:17535434

DNAzymes in DNA Nanomachines and DNA Analysis

NASA Astrophysics Data System (ADS)

He, Yu; Tian, Ye; Chen, Yi; Mao, Chengde

This chapter discusses our efforts in using DNAzymes in DNA nano-machines and DNA analysis systems. 10-23 DNAzymes can cleave specific phos-phodiester bonds in RNA. We use them to construct an autonomous DNA-RNA chimera nanomotor, which constantly extracts chemical energy from RNA substrates and transduces the energy into a mechanical motion: cycles of contraction and extension. The motor's motion can be reversibly turned on and off by a DNA analogue (brake) of the RNA substrate. Addition and removal of the brake stops and restarts, respectively, the motor's motion. Furthermore, when the RNA substrates are preorganized into a one-dimensional track, a DNAzyme can continuously move along the track so long as there are substrates available ahead. Based on a similar mechanism, a novel DNA detection system has been developed. A target DNA activates a DNAzyme to cleave RNA-containing molecular beacons (MB), which generates an enhanced fluorescence signal. A following work integrates two steps of signal amplifications: a rolling-circle amplification (RCA) to synthesize multiple copies of DNAzymes, and the DNAzymes catalyze a chemical reaction to generate a colorimetric signal. This method allows detection of DNA analytes whose concentration is as low as 1 pM.

Pseudomonas aeruginosa phage PaP1 DNA polymerase is an A-family DNA polymerase demonstrating ssDNA and dsDNA 3'-5' exonuclease activity.

PubMed

Liu, Binyan; Gu, Shiling; Liang, Nengsong; Xiong, Mei; Xue, Qizhen; Lu, Shuguang; Hu, Fuquan; Zhang, Huidong

2016-08-01

Most phages contain DNA polymerases, which are essential for DNA replication and propagation in infected host bacteria. However, our knowledge on phage-encoded DNA polymerases remains limited. This study investigated the function of a novel DNA polymerase of PaP1, which is the lytic phage of Pseudomonas aeruginosa. PaP1 encodes its sole DNA polymerase called Gp90 that was predicted as an A-family DNA polymerase with polymerase and 3'-5' exonuclease activities. The sequence of Gp90 is homologous but not identical to that of other A-family DNA polymerases, such as T7 DNA polymerases (Pol) and DNA Pol I. The purified Gp90 demonstrated a polymerase activity. The processivity of Gp90 in DNA replication and its efficiency in single-dNTP incorporation are similar to those of T7 Pol with processive thioredoxin (T7 Pol/trx). Gp90 can degrade ssDNA and dsDNA in 3'-5' direction at a similar rate, which is considerably lower than that of T7 Pol/trx. The optimized conditions for polymerization were a temperature of 37 °C and a buffer consisting of 40 mM Tris-HCl (pH 8.0), 30 mM MgCl2, and 200 mM NaCl. These studies on DNA polymerase encoded by PaP1 help advance our knowledge on phage-encoded DNA polymerases and elucidate PaP1 propagation in infected P. aeruginosa.

Programmable DNA Hydrogels Assembled from Multidomain DNA Strands.

PubMed

Jiang, Huiling; Pan, Victor; Vivek, Skanda; Weeks, Eric R; Ke, Yonggang

2016-06-16

Hydrogels are important in biological and medical applications, such as drug delivery and tissue engineering. DNA hydrogels have attracted significant attention due to the programmability and biocompatibility of the material. We developed a series of low-cost one-strand DNA hydrogels self-assembled from single-stranded DNA monomers containing multiple palindromic domains. This new hydrogel design is simple and programmable. Thermal stability, mechanical properties, and loading capacity of these one-strand DNA hydrogels can be readily regulated by simply adjusting the DNA domains. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Variola Type IB DNA Topoisomerase: DNA Binding and Supercoil Unwinding Using Engineered DNA Minicircles

PubMed Central

2015-01-01

Type IB topoisomerases unwind positive and negative DNA supercoils and play a key role in removing supercoils that would otherwise accumulate at replication and transcription forks. An interesting question is whether topoisomerase activity is regulated by the topological state of the DNA, thereby providing a mechanism for targeting the enzyme to highly supercoiled DNA domains in genomes. The type IB enzyme from variola virus (vTopo) has proven to be useful in addressing mechanistic questions about topoisomerase function because it forms a reversible 3′-phosphotyrosyl adduct with the DNA backbone at a specific target sequence (5′-CCCTT-3′) from which DNA unwinding can proceed. We have synthesized supercoiled DNA minicircles (MCs) containing a single vTopo target site that provides highly defined substrates for exploring the effects of supercoil density on DNA binding, strand cleavage and ligation, and unwinding. We observed no topological dependence for binding of vTopo to these supercoiled MC DNAs, indicating that affinity-based targeting to supercoiled DNA regions by vTopo is unlikely. Similarly, the cleavage and religation rates of the MCs were not topologically dependent, but topoisomers with low superhelical densities were found to unwind more slowly than highly supercoiled topoisomers, suggesting that reduced torque at low superhelical densities leads to an increased number of cycles of cleavage and ligation before a successful unwinding event. The K271E charge reversal mutant has an impaired interaction with the rotating DNA segment that leads to an increase in the number of supercoils that were unwound per cleavage event. This result provides evidence that interactions of the enzyme with the rotating DNA segment can restrict the number of supercoils that are unwound. We infer that both superhelical density and transient contacts between vTopo and the rotating DNA determine the efficiency of supercoil unwinding. Such determinants are likely to be

Transcription-induced DNA supercoiling: New roles of intranucleosomal DNA loops in DNA repair and transcription.

PubMed

Gerasimova, N S; Pestov, N A; Kulaeva, O I; Clark, D J; Studitsky, V M

2016-05-26

RNA polymerase II (Pol II) transcription through chromatin is accompanied by formation of small intranucleosomal DNA loops. Pol II captured within a small loop drives accumulation of DNA supercoiling, facilitating further transcription. DNA breaks relieve supercoiling and induce Pol II arrest, allowing detection of DNA damage hidden in chromatin structure.

Human DNA ligase III bridges two DNA ends to promote specific intermolecular DNA end joining

PubMed Central

Kukshal, Vandna; Kim, In-Kwon; Hura, Gregory L.; Tomkinson, Alan E.; Tainer, John A.; Ellenberger, Tom

2015-01-01

Mammalian DNA ligase III (LigIII) functions in both nuclear and mitochondrial DNA metabolism. In the nucleus, LigIII has functional redundancy with DNA ligase I whereas LigIII is the only mitochondrial DNA ligase and is essential for the survival of cells dependent upon oxidative respiration. The unique LigIII zinc finger (ZnF) domain is not required for catalytic activity but senses DNA strand breaks and stimulates intermolecular ligation of two DNAs by an unknown mechanism. Consistent with this activity, LigIII acts in an alternative pathway of DNA double strand break repair that buttresses canonical non-homologous end joining (NHEJ) and is manifest in NHEJ-defective cancer cells, but how LigIII acts in joining intermolecular DNA ends versus nick ligation is unclear. To investigate how LigIII efficiently joins two DNAs, we developed a real-time, fluorescence-based assay of DNA bridging suitable for high-throughput screening. On a nicked duplex DNA substrate, the results reveal binding competition between the ZnF and the oligonucleotide/oligosaccharide-binding domain, one of three domains constituting the LigIII catalytic core. In contrast, these domains collaborate and are essential for formation of a DNA-bridging intermediate by adenylated LigIII that positions a pair of blunt-ended duplex DNAs for efficient and specific intermolecular ligation. PMID:26130724

Transcription-induced DNA supercoiling: New roles of intranucleosomal DNA loops in DNA repair and transcription

PubMed Central

Gerasimova, N. S.; Pestov, N. A.; Kulaeva, O. I.; Clark, D. J.; Studitsky, V. M.

2016-01-01

ABSTRACT RNA polymerase II (Pol II) transcription through chromatin is accompanied by formation of small intranucleosomal DNA loops. Pol II captured within a small loop drives accumulation of DNA supercoiling, facilitating further transcription. DNA breaks relieve supercoiling and induce Pol II arrest, allowing detection of DNA damage hidden in chromatin structure. PMID:27115204

[Single-molecule detection and characterization of DNA replication based on DNA origami].

PubMed

Wang, Qi; Fan, Youjie; Li, Bin

2014-08-01

To investigate single-molecule detection and characterization of DNA replication. Single-stranded DNA (ssDNA) as the template of DNA replication was attached to DNA origami by a hybridization reaction based on the complementary base-pairing principle. DNA replication catalyzed by E.coli DNA polymerase I Klenow Fragment (KF) was detected using atomic force microscopy (AFM). The height variations between the ssDNA and the double-stranded DNA (dsDNA), the distribution of KF during DNA replication and biotin-streptavidin (BA) complexes on the DNA strand after replication were detected. Agarose gel electrophoresis was employed to analyze the changes in the DNA after replication. The designed ssDNA could be anchored on the target positions of over 50% of the DNA origami. The KF was capable of binding to the ssDNA fixed on DNA origami and performing its catalytic activities, and was finally dissociated from the DNA after replication. The height of DNA strand increased by about 0.7 nm after replication. The addition of streptavidin also resulted in an DNA height increase to about 4.9 nm due to the formation of BA complexes on the biotinylated dsDNA. The resulting dsDNA and BA complex were subsequently confirmed by agarose gel electrophoresis. The combination of AFM and DNA origami allows detection and characterization of DNA replication at the single molecule level, and this approach provides better insights into the mechanism of DNA polymerase and the factors affecting DNA replication.

Human leukocyte antigen typing using buccal swabs as accurate and non-invasive substitute for venipuncture in children at risk for celiac disease.

PubMed

Adriaanse, Marlou P M; Vreugdenhil, Anita C E; Vastmans, Véronique; Groeneveld, Lisette; Molenbroeck, Stefan; Schott, Dina A; Voorter, Christina E M; Tilanus, Marcel G J

2016-10-01

Human leukocyte antigen (HLA) typing is an important step in the diagnostic algorithm for celiac disease (CD) and is also used for screening purposes. Collection of blood is invasive and accompanied with emotional impact especially in children. Genetic technological progress now enables HLA typing from buccal cell samples. This study evaluated the reliability and feasibility of HLA typing for CD-associated HLA polymorphisms using buccal swabs as routine test in high-risk individuals. Blood and buccal swabs of 77 children and adolescents with high risk for CD were prospectively collected in this cohort study. Buccal swab collection was performed either by the investigator at the outpatient clinic or by the patient or its parents at home. To evaluate the possibility of self-administration, three families performed the test at home. DNA was extracted using an adapted QIAamp method. Quantity, quality, and purity of DNA were recorded. HLA-DRB1, HLA-DQA1, and HLA-DQB1 typing was examined on buccal cell-derived and blood-derived DNA at low and, if necessary, high resolution level, using sequence-specific oligonucleotide and sequence-based typing, respectively. DNA isolation using buccal swabs yielded a good quality and sufficient quantity of DNA to perform HLA-DQ typing in all individuals. HLA typing results on buccal cell-derived DNA were identical to typing on blood-derived DNA, also for the self-administered samples. Introduction of the buccal swab test for HLA typing of CD risk in routine diagnostics can omit the current venipuncture and enables self-administration at home. Therefore, the buccal swab test is beneficial for individuals with a clinical suspicion for CD, as well as for screening purposes in high-risk populations. © 2016 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

Multiple conformational states of DnaA protein regulate its interaction with DnaA boxes in the initiation of DNA replication.

PubMed

Patel, Meera J; Bhatia, Lavesh; Yilmaz, Gulden; Biswas-Fiss, Esther E; Biswas, Subhasis B

2017-09-01

DnaA protein is the initiator of genomic DNA replication in prokaryotes. It binds to specific DNA sequences in the origin of DNA replication and unwinds small AT-rich sequences downstream for the assembly of the replisome. The mechanism of activation of DnaA that enables it to bind and organize the origin DNA and leads to replication initiation remains unclear. In this study, we have developed double-labeled fluorescent DnaA probes to analyze conformational states of DnaA protein upon binding DNA, nucleotide, and Soj sporulation protein using Fluorescence Resonance Energy Transfer (FRET). Our studies demonstrate that DnaA protein undergoes large conformational changes upon binding to substrates and there are multiple distinct conformational states that enable it to initiate DNA replication. DnaA protein adopted a relaxed conformation by expanding ~15Å upon binding ATP and DNA to form the ATP·DnaA·DNA complex. Hydrolysis of bound ATP to ADP led to a contraction of DnaA within the complex. The relaxed conformation of DnaA is likely required for the formation of the multi-protein ATP·DnaA·DNA complex. In the initiation of sporulation, Soj binding to DnaA prevented relaxation of its conformation. Soj·ADP appeared to block the activation of DnaA, suggesting a mechanism for Soj·ADP in switching initiation of DNA replication to sporulation. Our studies demonstrate that multiple conformational states of DnaA protein regulate its binding to DNA in the initiation of DNA replication. Copyright © 2017 Elsevier B.V. All rights reserved.

Flexible DNA bending in HU–DNA cocrystal structures

PubMed Central

Swinger, Kerren K.; Lemberg, Kathryn M.; Zhang, Ying; Rice, Phoebe A.

2003-01-01

HU and IHF are members of a family of prokaryotic proteins that interact with the DNA minor groove in a sequence-specific (IHF) or non-specific (HU) manner to induce and/or stabilize DNA bending. HU plays architectural roles in replication initiation, transcription regulation and site-specific recombination, and is associated with bacterial nucleoids. Cocrystal structures of Anabaena HU bound to DNA (1P71, 1P78, 1P51) reveal that while underlying proline intercalation and asymmetric charge neutralization mechanisms of DNA bending are similar for IHF and HU, HU stabilizes different DNA bend angles (∼105–140°). The two bend angles within a single HU complex are not coplanar, and the resulting dihedral angle is consistent with negative supercoiling. Comparison of HU–DNA and IHF–DNA structures suggests that sharper bending is correlated with longer DNA binding sites and smaller dihedral angles. An HU-induced bend may be better modeled as a hinge, not a rigid bend. The ability to induce or stabilize varying bend angles is consistent with HU’s role as an architectural cofactor in many different systems that may require differing geometries. PMID:12853489

A survey of DNA diagnostic laboratories regarding DNA banking.

PubMed Central

McEwen, J E; Reilly, P R

1995-01-01

This article reports the findings of a survey of 148 academically based and commercial DNA diagnostic labs regarding DNA banking (defined as the storage of individual DNA samples in some form with identifiers for later retrieval). The population surveyed consisted of all laboratories listed with HELIX, a national directory of DNA diagnostic labs that includes a fairly comprehensive listing of clinical service labs as well as a large number of research labs. The survey was concerned primarily with the legal and ethical issues that the long-term storage of DNA may raise. The survey inquired into the respondents' policies and procedures concerning (1) the extent of DNA banking and of interest in developing DNA banking in academia and industry and (2) the degree to which DNA banks had developed written internal policies and/or a written depositor's agreement (a signed document defining the rights and obligations of the person from whom the sample was taken and the bank) designed to anticipate or prevent some of the ethical and legal problems that can arise from the long-term retention of DNA. Our research suggests that (1) the activity of DNA banking is growing, particularly in the academic setting, and (2) most academically based DNA banks lack written internal policies, written depositor's agreements, or other relevant documentation regarding important aspects of this activity. PMID:7762571

DNA glycosylases search for and remove oxidized DNA bases.

PubMed

Wallace, Susan S

2013-12-01

This review article presents, an overview of the DNA glycosylases that recognize oxidized DNA bases using the Fpg/Nei family of DNA glycosylases as models for how structure can inform function. For example, even though human NEIL1 and the plant and fungal orthologs lack the zinc finger shown to be required for binding, DNA crystal structures revealed a "zincless finger" with the same properties. Moreover, the "lesion recognition loop" is not involved in lesion recognition, rather, it stabilizes 8-oxoG in the active site pocket. Unlike the other Fpg/Nei family members, Neil3 lacks two of the three void-filling residues that stabilize the DNA duplex and interact with the opposite strand to the damage which may account for its preference for lesions in single-stranded DNA. Also single-molecule approaches show that DNA glycosylases search for their substrates in a sea of undamaged DNA by using a wedge residue that is inserted into the DNA helix to probe for the presence of damage. Copyright © 2013 Wiley Periodicals, Inc.

Shedding of porcine circovirus type 1 DNA and rotavirus RNA by infants vaccinated with Rotarix®

PubMed Central

Mijatovic-Rustempasic, Slavica; Immergluck, Lilly Cheng; Parker, Trisha Chan; Laghaie, Elham; Mohammed, Anaam; McFadden, Terri; Parashar, Umesh D.; Bowen, Michael D.; Cortese, Margaret M.

2017-01-01

ABSTRACT Thirty-three infants aged ∼2 months had serial stool samples collected after receipt of Rotarix® vaccine dose 1, and were assessed for shedding of porcine circovirus type 1 DNA and Rotavirus group A RNA by molecular methods. We did not find strong evidence that porcine circovirus type 1 replication occurred. Porcine circovirus type 1 genome with the same sequence as that in Rotarix® was detected in a few infants as late as day ≥ 13; while this timing could suggest there may have been replication and not just transient passage through the gastrointestinal tract, the lack of increase in copy number in any infant supports transient passage and there are inherent limitations to the results. We found that 21% of infants did not shed Rotarix® RVA RNA beyond the day 3 sample, which may suggest lack of vaccine virus replication. Of the infants in whom Rotarix RVA RNA shedding continued, peak copy numbers were reached on days 3–5 for ∼40%, and after day 5 in ∼60%, and shedding can be prolonged (≥ 45 days). PMID:27936349

Making the Bend: DNA Tertiary Structure and Protein-DNA Interactions

PubMed Central

Harteis, Sabrina; Schneider, Sabine

2014-01-01

DNA structure functions as an overlapping code to the DNA sequence. Rapid progress in understanding the role of DNA structure in gene regulation, DNA damage recognition and genome stability has been made. The three dimensional structure of both proteins and DNA plays a crucial role for their specific interaction, and proteins can recognise the chemical signature of DNA sequence (“base readout”) as well as the intrinsic DNA structure (“shape recognition”). These recognition mechanisms do not exist in isolation but, depending on the individual interaction partners, are combined to various extents. Driving force for the interaction between protein and DNA remain the unique thermodynamics of each individual DNA-protein pair. In this review we focus on the structures and conformations adopted by DNA, both influenced by and influencing the specific interaction with the corresponding protein binding partner, as well as their underlying thermodynamics. PMID:25026169

Loss of maintenance DNA methylation results in abnormal DNA origin firing during DNA replication.

PubMed

Haruta, Mayumi; Shimada, Midori; Nishiyama, Atsuya; Johmura, Yoshikazu; Le Tallec, Benoît; Debatisse, Michelle; Nakanishi, Makoto

2016-01-22

The mammalian maintenance methyltransferase DNMT1 [DNA (cytosine-5-)-methyltransferase 1] mediates the inheritance of the DNA methylation pattern during replication. Previous studies have shown that depletion of DNMT1 causes a severe growth defect and apoptosis in differentiated cells. However, the detailed mechanisms behind this phenomenon remain poorly understood. Here we show that conditional ablation of Dnmt1 in murine embryonic fibroblasts (MEFs) resulted in an aberrant DNA replication program showing an accumulation of late-S phase replication and causing severely defective growth. Furthermore, we found that the catalytic activity and replication focus targeting sequence of DNMT1 are required for a proper DNA replication program. Taken together, our findings suggest that the maintenance of DNA methylation by DNMT1 plays a critical role in proper regulation of DNA replication in mammalian cells. Copyright © 2015 Elsevier Inc. All rights reserved.

Mechanisms of mutagenesis: DNA replication in the presence of DNA damage

PubMed Central

Liu, Binyan; Xue, Qizhen; Tang, Yong; Cao, Jia; Guengerich, F. Peter; Zhang, Huidong

2017-01-01

Environmental mutagens cause DNA damage that disturbs replication and produces mutations, leading to cancer and other diseases. We discuss mechanisms of mutagenesis resulting from DNA damage, from the level of DNA replication by a single polymerase to the complex DNA replisome of some typical model organisms (including bacteriophage T7, T4, Sulfolobus solfataricus, E. coli, yeast and human). For a single DNA polymerase, DNA damage can affect replication in three major ways: reducing replication fidelity, causing frameshift mutations, and blocking replication. For the DNA replisome, protein interactions and the functions of accessory proteins can yield rather different results even with a single DNA polymerase. The mechanism of mutation during replication performed by the DNA replisome is a long-standing question. Using new methods and techniques, the replisomes of certain organisms and human cell extracts can now be investigated with regard to the bypass of DNA damage. In this review, we consider the molecular mechanism of mutagenesis resulting from DNA damage in replication at the levels of single DNA polymerases and complex DNA replisomes, including translesion DNA synthesis. PMID:27234563

Herpes Simplex Virus DNA Packaging without Measurable DNA Synthesis

PubMed Central

Church, Geoffrey A.; Dasgupta, Anindya; Wilson, Duncan W.

1998-01-01

Herpes simplex virus (HSV) type 1 DNA synthesis and packaging occur within the nuclei of infected cells; however, the extent to which the two processes are coupled remains unclear. Correct packaging is thought to be dependent upon DNA debranching or other repair processes, and such events commonly involve new DNA synthesis. Furthermore, the HSV UL15 gene product, essential for packaging, nevertheless localizes to sites of active DNA replication and may link the two events. It has previously been difficult to determine whether packaging requires concomitant DNA synthesis due to the complexity of these processes and of the viral life cycle; however, we have recently described a model system which simplifies the study of HSV assembly. Cells infected with HSV strain tsProt.A accumulate unpackaged capsids at the nonpermissive temperature of 39°C. Following release of the temperature block, these capsids proceed to package viral DNA in a single, synchronous wave. Here we report that, when DNA replication was inhibited prior to release of the temperature block, DNA packaging and later events in viral assembly nevertheless occurred at near-normal levels. We conclude that, under our conditions, HSV DNA packaging does not require detectable levels of DNA synthesis. PMID:9525593

Human DNA ligase III bridges two DNA ends to promote specific intermolecular DNA end joining.

PubMed

Kukshal, Vandna; Kim, In-Kwon; Hura, Gregory L; Tomkinson, Alan E; Tainer, John A; Ellenberger, Tom

2015-08-18

Mammalian DNA ligase III (LigIII) functions in both nuclear and mitochondrial DNA metabolism. In the nucleus, LigIII has functional redundancy with DNA ligase I whereas LigIII is the only mitochondrial DNA ligase and is essential for the survival of cells dependent upon oxidative respiration. The unique LigIII zinc finger (ZnF) domain is not required for catalytic activity but senses DNA strand breaks and stimulates intermolecular ligation of two DNAs by an unknown mechanism. Consistent with this activity, LigIII acts in an alternative pathway of DNA double strand break repair that buttresses canonical non-homologous end joining (NHEJ) and is manifest in NHEJ-defective cancer cells, but how LigIII acts in joining intermolecular DNA ends versus nick ligation is unclear. To investigate how LigIII efficiently joins two DNAs, we developed a real-time, fluorescence-based assay of DNA bridging suitable for high-throughput screening. On a nicked duplex DNA substrate, the results reveal binding competition between the ZnF and the oligonucleotide/oligosaccharide-binding domain, one of three domains constituting the LigIII catalytic core. In contrast, these domains collaborate and are essential for formation of a DNA-bridging intermediate by adenylated LigIII that positions a pair of blunt-ended duplex DNAs for efficient and specific intermolecular ligation. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Synthesis of bacteriophage phiC DNA in dna mutants of Esherichia coli.

PubMed

Kodaira, K I; Taketo, A

1978-06-01

Host dna functions involved in the replication of microvirid phage phiC DNA were investigated in vivo. Although growth of this phage was markedly inhibited even at 35-37 degrees C even in dna+ host, conversion of the infecting single-stranded DNA into the double-stranded parental replicative form (stage I synthesis) occurred normally at 43 degrees C in dna+, dnaA, dnaB, dnaC(D), and dnaE cells. In dnaG mutant, the stage I synthesis was severely inhibited at 43 degrees C but not at 30 degrees C. The stage I replication of phiC DNA was clearly thermosensitive in dnaZ cells incubated in nutrient broth. In Tris-casamino acids-glucose medium, however, the dnaZ mutant sufficiently supported synthesis of the parental replicative form. At 43 degrees C, synthesis of the progeny replicative form DNA (stage II replication) was significantly inhibited even in dna+ cells and was nearly completely blocked in dnaB or dnaC(D) mutant. At 37 degrees C, the stage II replication proceeded normally in dna+ bacteria.

Detection of regional DNA methylation using DNA-graphene affinity interactions.

PubMed

Haque, Md Hakimul; Gopalan, Vinod; Yadav, Sharda; Islam, Md Nazmul; Eftekhari, Ehsan; Li, Qin; Carrascosa, Laura G; Nguyen, Nam-Trung; Lam, Alfred K; Shiddiky, Muhammad J A

2017-01-15

We report a new method for the detection of regional DNA methylation using base-dependent affinity interaction (i.e., adsorption) of DNA with graphene. Due to the strongest adsorption affinity of guanine bases towards graphene, bisulfite-treated guanine-enriched methylated DNA leads to a larger amount of the adsorbed DNA on the graphene-modified electrodes in comparison to the adenine-enriched unmethylated DNA. The level of the methylation is quantified by monitoring the differential pulse voltammetric current as a function of the adsorbed DNA. The assay is sensitive to distinguish methylated and unmethylated DNA sequences at single CpG resolution by differentiating changes in DNA methylation as low as 5%. Furthermore, this method has been used to detect methylation levels in a collection of DNA samples taken from oesophageal cancer tissues. Copyright © 2016 Elsevier B.V. All rights reserved.

Yeast Helicase Pif1 Unwinds RNA:DNA Hybrids with Higher Processivity than DNA:DNA Duplexes*

PubMed Central

Chib, Shubeena; Byrd, Alicia K.; Raney, Kevin D.

2016-01-01

Saccharomyces cerevisiae Pif1, an SF1B helicase, has been implicated in both mitochondrial and nuclear functions. Here we have characterized the preference of Pif1 for RNA:DNA heteroduplexes in vitro by investigating several kinetic parameters associated with unwinding. We show that the preferential unwinding of RNA:DNA hybrids is due to neither specific binding nor differences in the rate of strand separation. Instead, Pif1 is capable of unwinding RNA:DNA heteroduplexes with moderately greater processivity compared with its duplex DNA:DNA counterparts. This higher processivity of Pif1 is attributed to slower dissociation from RNA:DNA hybrids. Biologically, this preferential role of the helicase may contribute to its functions at both telomeric and nontelomeric sites. PMID:26733194

DNA banking and DNA databanking by academic and commercial laboratories

DOE Office of Scientific and Technical Information (OSTI.GOV)

McEwen, J.E.; Reilly, P.R.

The advent of DNA-based testing is giving rise to DNA banking (the long-term storage of cells, transformed cell lines, or extracted DNA for subsequent retrieval and analysis) and DNA data banking (the indefinite storage of information derived from DNA analysis). Large scale acquisition and storage of DNA and DNA data has important implications for the privacy rights of individuals. A survey of 148 academically based and commercial DNA diagnostic laboratories was conducted to determine: (1) the extent of their DNA banking activities; (2) their policies and experiences regarding access to DNA samples and data; (3) the quality assurance measures theymore » employ; and (4) whether they have written policies and/or depositor`s agreements addressing specific issues. These issues include: (1) who may have access to DNA samples and data; (2) whether scientists may have access to anonymous samples or data for research use; (3) whether they have plans to contact depositors or retest samples if improved tests for a disorder become available; (4) disposition of samples at the end of the contract period if the laboratory ceases operations, if storage fees are unpaid, or after a death or divorce; (5) the consequence of unauthorized release, loss, or accidental destruction of samples; and (6) whether depositors may share in profits from the commercialization of tests or treatments developed in part from studies of stored DNA. The results suggest that many laboratories are banking DNA, that many have already amassed a large number of samples, and that a significant number plan to further develop DNA banking as a laboratory service over the next two years. Few laboratories have developed written policies governing DNA banking, and fewer still have drafted documents that define the rights and obligations of the parties. There may be a need for increased regulation of DNA banking and DNA data banking and for better defined policies with respect to protecting individual privacy.« less

Diversification of DnaA dependency for DNA replication in cyanobacterial evolution.

PubMed

Ohbayashi, Ryudo; Watanabe, Satoru; Ehira, Shigeki; Kanesaki, Yu; Chibazakura, Taku; Yoshikawa, Hirofumi

2016-05-01

Regulating DNA replication is essential for all living cells. The DNA replication initiation factor DnaA is highly conserved in prokaryotes and is required for accurate initiation of chromosomal replication at oriC. DnaA-independent free-living bacteria have not been identified. The dnaA gene is absent in plastids and some symbiotic bacteria, although it is not known when or how DnaA-independent mechanisms were acquired. Here, we show that the degree of dependency of DNA replication on DnaA varies among cyanobacterial species. Deletion of the dnaA gene in Synechococcus elongatus PCC 7942 shifted DNA replication from oriC to a different site as a result of the integration of an episomal plasmid. Moreover, viability during the stationary phase was higher in dnaA disruptants than in wild-type cells. Deletion of dnaA did not affect DNA replication or cell growth in Synechocystis sp. PCC 6803 or Anabaena sp. PCC 7120, indicating that functional dependency on DnaA was already lost in some nonsymbiotic cyanobacterial lineages during diversification. Therefore, we proposed that cyanobacteria acquired DnaA-independent replication mechanisms before symbiosis and such an ancestral cyanobacterium was the sole primary endosymbiont to form a plastid precursor.

Mechanisms of mutagenesis: DNA replication in the presence of DNA damage.

PubMed

Liu, Binyan; Xue, Qizhen; Tang, Yong; Cao, Jia; Guengerich, F Peter; Zhang, Huidong

2016-01-01

Environmental mutagens cause DNA damage that disturbs replication and produces mutations, leading to cancer and other diseases. We discuss mechanisms of mutagenesis resulting from DNA damage, from the level of DNA replication by a single polymerase to the complex DNA replisome of some typical model organisms (including bacteriophage T7, T4, Sulfolobus solfataricus, Escherichia coli, yeast and human). For a single DNA polymerase, DNA damage can affect replication in three major ways: reducing replication fidelity, causing frameshift mutations, and blocking replication. For the DNA replisome, protein interactions and the functions of accessory proteins can yield rather different results even with a single DNA polymerase. The mechanism of mutation during replication performed by the DNA replisome is a long-standing question. Using new methods and techniques, the replisomes of certain organisms and human cell extracts can now be investigated with regard to the bypass of DNA damage. In this review, we consider the molecular mechanism of mutagenesis resulting from DNA damage in replication at the levels of single DNA polymerases and complex DNA replisomes, including translesion DNA synthesis. Copyright © 2016 Elsevier B.V. All rights reserved.

Foldback intercoil DNA and the mechanism of DNA transposition.

PubMed

Kim, Byung-Dong

2014-09-01

Foldback intercoil (FBI) DNA is formed by the folding back at one point of a non-helical parallel track of double-stranded DNA at as sharp as 180° and the intertwining of two double helixes within each other's major groove to form an intercoil with a diameter of 2.2 nm. FBI DNA has been suggested to mediate intra-molecular homologous recombination of a deletion and inversion. Inter-molecular homologous recombination, known as site-specific insertion, on the other hand, is mediated by the direct perpendicular approach of the FBI DNA tip, as the attP site, onto the target DNA, as the attB site. Transposition of DNA transposons involves the pairing of terminal inverted repeats and 5-7-bp tandem target duplication. FBI DNA configuration effectively explains simple as well as replicative transposition, along with the involvement of an enhancer element. The majority of diverse retrotransposable elements that employ a target site duplication mechanism is also suggested to follow the FBI DNA-mediated perpendicular insertion of the paired intercoil ends by non-homologous end-joining, together with gap filling. A genome-wide perspective of transposable elements in light of FBI DNA is discussed.

Quantitation of HBV DNA in human serum using a branched DNA (bDNA) signal amplification assay.

PubMed

Hendricks, D A; Stowe, B J; Hoo, B S; Kolberg, J; Irvine, B D; Neuwald, P D; Urdea, M S; Perrillo, R P

1995-11-01

The aim of this study was to establish the performance characteristics of a nonradioisotopic branched DNA (bDNA) signal amplification assay for quantitation of hepatitis B virus (HBV) DNA in human serum. Quantitation was determined from a standard curve and expressed as HBV DNA equivalents/mL (Eq/mL; 285,000 Eq = 1 pg of double stranded HBV DNA). The bDNA assay exhibited a nearly four log dynamic range of quantitation and an analytical detection limit of approximately 100,000 Eq/mL. To ensure a specificity of 99.7%, the quantitation limit was set at 700,000 Eq/mL. The interassay percent coefficient of variance for quantification values ranged from 10% to 15% when performed by novice users with different sets of reagents. Using the bDNA assay, HBV DNA was detected in 94% to 100% of hepatitis B e antigen-positive specimens and 27% to 31% of hepatitis B e antigen-negative specimens from chronic HBV-infected patients. The bDNA assay may be useful as a prognostic and therapy monitoring tool for the management of HBV-infected patients undergoing antiviral treatment.

Crystal Structure of the Chromodomain Helicase DNA-binding Protein 1 (Chd1) DNA-binding Domain in Complex with DNA*

PubMed Central

Sharma, Amit; Jenkins, Katherine R.; Héroux, Annie; Bowman, Gregory D.

2011-01-01

Chromatin remodelers are ATP-dependent machines that dynamically alter the chromatin packaging of eukaryotic genomes by assembling, sliding, and displacing nucleosomes. The Chd1 chromatin remodeler possesses a C-terminal DNA-binding domain that is required for efficient nucleosome sliding and believed to be essential for sensing the length of DNA flanking the nucleosome core. The structure of the Chd1 DNA-binding domain was recently shown to consist of a SANT and SLIDE domain, analogous to the DNA-binding domain of the ISWI family, yet the details of how Chd1 recognized DNA were not known. Here we present the crystal structure of the Saccharomyces cerevisiae Chd1 DNA-binding domain in complex with a DNA duplex. The bound DNA duplex is straight, consistent with the preference exhibited by the Chd1 DNA-binding domain for extranucleosomal DNA. Comparison of this structure with the recently solved ISW1a DNA-binding domain bound to DNA reveals that DNA lays across each protein at a distinct angle, yet contacts similar surfaces on the SANT and SLIDE domains. In contrast to the minor groove binding seen for Isw1 and predicted for Chd1, the SLIDE domain of the Chd1 DNA-binding domain contacts the DNA major groove. The majority of direct contacts with the phosphate backbone occur only on one DNA strand, suggesting that Chd1 may not strongly discriminate between major and minor grooves. PMID:22033927

Titration of DnaA protein by oriC DnaA-boxes increases dnaA gene expression in Escherichia coli.

PubMed Central

Hansen, F G; Koefoed, S; Sørensen, L; Atlung, T

1987-01-01

Binding of the DnaA protein to its binding sites, the DnaA-boxes (TTATCCACA), was measured by a simple physiological approach. The presence of extra DnaA-boxes in growing cells leads to a derepression of dnaA gene expression, measured as beta-galactosidase activity of a dnaA-lacZ fusion polypeptide. Different DnaA-boxes caused different degrees of derepression indicating that the DnaA protein requires sequences in addition to the DnaA-box for efficient binding. The DnaA-boxes in oriC might act cooperatively in binding of the DnaA protein. The derepressed levels of DnaA protein obtained in a strain carrying an oriC+-pBR322 chimera were very high and sufficient to activate oriC on the chimeric plasmid, which was maintained at a copy number more than three times that of pBR322. PMID:3034578

Electrotransformation of highly DNA-restrictive corynebacteria with synthetic DNA.

PubMed

Ankri, S; Reyes, O; Leblon, G

1996-01-01

Highly DNA-restrictive Corynebacteria can be transformed with DNA made in vitro by PCR amplification of a sequence that contains the replication origin of pBL1, a plasmid common to many Corynebacteria. In all strains examined, the transformation efficiencies of PCR-synthetized DNA equal or improve the performances of heterologous DNA extracted from wild-type and dam(-)-dcm-strains of Escherichia coli. The transformation efficiencies obtained with PCR-made DNA may be high enough to permit its general application to experiments of gene integration.

Structural and Thermodynamic Signatures of DNA Recognition by Mycobacterium tuberculosis DnaA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsodikov, Oleg V.; Biswas, Tapan

An essential protein, DnaA, binds to 9-bp DNA sites within the origin of replication oriC. These binding events are prerequisite to forming an enigmatic nucleoprotein scaffold that initiates replication. The number, sequences, positions, and orientations of these short DNA sites, or DnaA boxes, within the oriCs of different bacteria vary considerably. To investigate features of DnaA boxes that are important for binding Mycobacterium tuberculosis DnaA (MtDnaA), we have determined the crystal structures of the DNA binding domain (DBD) of MtDnaA bound to a cognate MtDnaA-box (at 2.0 {angstrom} resolution) and to a consensus Escherichia coli DnaA-box (at 2.3 {angstrom}). Thesemore » structures, complemented by calorimetric equilibrium binding studies of MtDnaA DBD in a series of DnaA-box variants, reveal the main determinants of DNA recognition and establish the [T/C][T/A][G/A]TCCACA sequence as a high-affinity MtDnaA-box. Bioinformatic and calorimetric analyses indicate that DnaA-box sequences in mycobacterial oriCs generally differ from the optimal binding sequence. This sequence variation occurs commonly at the first 2 bp, making an in vivo mycobacterial DnaA-box effectively a 7-mer and not a 9-mer. We demonstrate that the decrease in the affinity of these MtDnaA-box variants for MtDnaA DBD relative to that of the highest-affinity box TTGTCCACA is less than 10-fold. The understanding of DnaA-box recognition by MtDnaA and E. coli DnaA enables one to map DnaA-box sequences in the genomes of M. tuberculosis and other eubacteria.« less

Molecular characterization of diarrheagenic Escherichia coli strains from stools samples and food products in Colombia

PubMed Central

Rúgeles, Laura Cristina; Bai, Jing; Martínez, Aída Juliana; Vanegas, María Consuelo; Gómez-Duarte, Oscar Gilberto

2010-01-01

The prevalence of diarrheagenic E. coli in childhood diarrhea and the role of contaminated food products in disease transmission in Colombia are largely unknown. The aim of this study is to identify E. coli pathotypes, including E. coli O157:H7, from 108 stool samples from children with acute diarrhea, 38 meat samples and 38 vegetable samples. Multiplex PCR and Bax Dupont systems were used for E. coli pathotype detection. Eighteen (9.8%) E. coli diarrheagenic pathotypes were detected among all clinical and food product samples tested. Four different pathotypes were identified from clinical samples, including enteroaggregative E. coli, enterotoxigenic E. coli, shiga-toxin producing E. coli, and enteropathogenic E. coli. Food product samples were positive for enteroaggregative and shiga-toxin producing E. coli, suggesting that meat and vegetables may be involved in transmission of these E. coli pathotypes in the community. Most E. coli strains identified belong to the phylogenetic groups A and B1, known to be associated with intestinal rather than extraintestinal E. coli clones. Our data is the first molecular E. coli report that confirms the presence of E. coli pathotypes circulating in Colombia among children with diarrhea and food products for human consumption. Implementation of multiplex PCR technology in Latin America and other countries with limited resources may provide an important epidemiological tool for the surveillance of E. coli pathotypes from clinical isolates as well as from water and food product samples. PMID:20153069

Synthesis of DNA

DOEpatents

Mariella, Jr., Raymond P.

2008-11-18

A method of synthesizing a desired double-stranded DNA of a predetermined length and of a predetermined sequence. Preselected sequence segments that will complete the desired double-stranded DNA are determined. Preselected segment sequences of DNA that will be used to complete the desired double-stranded DNA are provided. The preselected segment sequences of DNA are assembled to produce the desired double-stranded DNA.

Site-directed DNA crosslinking of large multisubunit protein-DNA complexes.

PubMed

Persinger, Jim; Bartholomew, Blaine

2009-01-01

Several methods have been developed to site-specifically incorporate photoreactive nucleotide analogs into DNA for the purpose of identifying the proteins and their domains that are in contact with particular regions of DNA. The synthesis of several deoxynucleotide analogs that have a photoreactive group tethered to the nucleotide base and the incorporation of these analogs into DNA are described. In a second approach, oligonucleotide with a photoreactive group attached to the phosphate backbone is chemically synthesized. The photoreactive oligonucleotide is then enzymatically incorporated into DNA by annealing it to a complementary DNA template and extending with DNA polymerase. Both approaches have been effectively used to map protein-DNA interactions in large multisubunit complexes such as the eukaryotic transcription or ATP-dependent chromatin remodeling complexes. Not only do these techniques map the binding sites of the various subunits in these complexes, but when coupled with peptide mapping also determine the protein domain that is in close proximity to the different DNA sites. The strength of these techniques is the ability to scan a large number of potential sites by making combinations of different DNA probes and is facilitated by using an immobilized DNA template for synthesis.

Drosha drives the formation of DNA:RNA hybrids around DNA break sites to facilitate DNA repair.

PubMed

Lu, Wei-Ting; Hawley, Ben R; Skalka, George L; Baldock, Robert A; Smith, Ewan M; Bader, Aldo S; Malewicz, Michal; Watts, Felicity Z; Wilczynska, Ania; Bushell, Martin

2018-02-07

The error-free and efficient repair of DNA double-stranded breaks (DSBs) is extremely important for cell survival. RNA has been implicated in the resolution of DNA damage but the mechanism remains poorly understood. Here, we show that miRNA biogenesis enzymes, Drosha and Dicer, control the recruitment of repair factors from multiple pathways to sites of damage. Depletion of Drosha significantly reduces DNA repair by both homologous recombination (HR) and non-homologous end joining (NHEJ). Drosha is required within minutes of break induction, suggesting a central and early role for RNA processing in DNA repair. Sequencing of DNA:RNA hybrids reveals RNA invasion around DNA break sites in a Drosha-dependent manner. Removal of the RNA component of these structures results in impaired repair. These results show how RNA can be a direct and critical mediator of DNA damage repair in human cells.

Molecular mechanism of DNA association with single-stranded DNA binding protein

PubMed Central

Maffeo, Christopher

2017-01-01

Abstract During DNA replication, the single-stranded DNA binding protein (SSB) wraps single-stranded DNA (ssDNA) with high affinity to protect it from degradation and prevent secondary structure formation. Although SSB binds ssDNA tightly, it can be repositioned along ssDNA to follow the advancement of the replication fork. Using all-atom molecular dynamics simulations, we characterized the molecular mechanism of ssDNA association with SSB. Placed in solution, ssDNA–SSB assemblies were observed to change their structure spontaneously; such structural changes were suppressed in the crystallographic environment. Repeat simulations of the SSB–ssDNA complex under mechanical tension revealed a multitude of possible pathways for ssDNA to come off SSB punctuated by prolonged arrests at reproducible sites at the SSB surface. Ensemble simulations of spontaneous association of short ssDNA fragments with SSB detailed a three-dimensional map of local affinity to DNA; the equilibrium amount of ssDNA bound to SSB was found to depend on the electrolyte concentration but not on the presence of the acidic tips of the SSB tails. Spontaneous formation of ssDNA bulges and their diffusive motion along SSB surface was directly observed in multiple 10-µs-long simulations. Such reptation-like motion was confined by DNA binding to high-affinity spots, suggesting a two-step mechanism for SSB diffusion. PMID:29059392

Competition for DNA binding sites using Promega DNA IQ™ paramagnetic beads.

PubMed

Frégeau, Chantal J; De Moors, Anick

2012-09-01

The Promega DNA IQ™ system is easily amenable to automation and has been an integral part of standard operating procedures for many forensic laboratories including those of the Royal Canadian Mounted Police (RCMP) since 2004. Due to some failure to extract DNA from samples that should have produced DNA using our validated automated DNA IQ™-based protocol, the competition for binding sites on the DNA IQ™ magnetic beads was more closely examined. Heme from heavily blooded samples interfered slightly with DNA binding. Increasing the concentration of Proteinase K during lysis of these samples did not enhance DNA recovery. However, diluting the sample lysate following lysis prior to DNA extraction overcame the reduction in DNA yield and preserved portions of the lysates for subsequent manual or automated extraction. Dye/chemicals from black denim lysates competed for binding sites on the DNA IQ™ beads and significantly reduced DNA recovery. Increasing the size or number of black denim cuttings during lysis had a direct adverse effect on DNA yield from various blood volumes. The dilution approach was successful on these samples and permitted the extraction of high DNA yields. Alternatively, shortening the incubation time for cell lysis to 30 min instead of the usual overnight at 56 °C prevented competition from black denim dye/chemicals and increased DNA yields. Crown Copyright © 2011. Published by Elsevier Ireland Ltd. All rights reserved.

Binding of undamaged double stranded DNA to vaccinia virus uracil-DNA glycosylase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schormann, Norbert; Banerjee, Surajit; Ricciardi, Robert

Background: Uracil-DNA glycosylases are evolutionarily conserved DNA repair enzymes. However, vaccinia virus uracil-DNA glycosylase (known as D4), also serves as an intrinsic and essential component of the processive DNA polymerase complex during DNA replication. In this complex D4 binds to a unique poxvirus specific protein A20 which tethers it to the DNA polymerase. At the replication fork the DNA scanning and repair function of D4 is coupled with DNA replication. So far, DNA-binding to D4 has not been structurally characterized. Results: This manuscript describes the first structure of a DNA-complex of a uracil-DNA glycosylase from the poxvirus family. This alsomore » represents the first structure of a uracil DNA glycosylase in complex with an undamaged DNA. In the asymmetric unit two D4 subunits bind simultaneously to complementary strands of the DNA double helix. Each D4 subunit interacts mainly with the central region of one strand. DNA binds to the opposite side of the A20-binding surface on D4. In comparison of the present structure with the structure of uracil-containing DNA-bound human uracil-DNA glycosylase suggests that for DNA binding and uracil removal D4 employs a unique set of residues and motifs that are highly conserved within the poxvirus family but different in other organisms. Conclusion: The first structure of D4 bound to a truly non-specific undamaged double-stranded DNA suggests that initial binding of DNA may involve multiple non-specific interactions between the protein and the phosphate backbone.« less

Binding of undamaged double stranded DNA to vaccinia virus uracil-DNA glycosylase

DOE PAGES

Schormann, Norbert; Banerjee, Surajit; Ricciardi, Robert; ...

2015-06-02

Background: Uracil-DNA glycosylases are evolutionarily conserved DNA repair enzymes. However, vaccinia virus uracil-DNA glycosylase (known as D4), also serves as an intrinsic and essential component of the processive DNA polymerase complex during DNA replication. In this complex D4 binds to a unique poxvirus specific protein A20 which tethers it to the DNA polymerase. At the replication fork the DNA scanning and repair function of D4 is coupled with DNA replication. So far, DNA-binding to D4 has not been structurally characterized. Results: This manuscript describes the first structure of a DNA-complex of a uracil-DNA glycosylase from the poxvirus family. This alsomore » represents the first structure of a uracil DNA glycosylase in complex with an undamaged DNA. In the asymmetric unit two D4 subunits bind simultaneously to complementary strands of the DNA double helix. Each D4 subunit interacts mainly with the central region of one strand. DNA binds to the opposite side of the A20-binding surface on D4. In comparison of the present structure with the structure of uracil-containing DNA-bound human uracil-DNA glycosylase suggests that for DNA binding and uracil removal D4 employs a unique set of residues and motifs that are highly conserved within the poxvirus family but different in other organisms. Conclusion: The first structure of D4 bound to a truly non-specific undamaged double-stranded DNA suggests that initial binding of DNA may involve multiple non-specific interactions between the protein and the phosphate backbone.« less