Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “fecal sample”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed2001

Evaluation of a latex agglutination kit (Virogen Rotatest) for detection of bovine rotavirus in fecal samples.

The performance of the Virogen Rotatest latex agglutination test (LAT) was evaluated for detection of bovine rotavirus antigen. Sixty-three fecal samples from diarrheic calves were collected from November 1999 to May 2000 and screened by LAT, the Rotazyme II enzyme-linked immunosorbent assay (ELISA), and virus isolation (VI) followed by an anti-rotavirus fluorescent-antibody (FA) test to detect the presence of group A rotavirus antigen. Of the 63 samples screened by VI-FA, 33 (58%) tested positive for rotavirus antigen. When the results from the LAT were compared to those from VI-FA, the "gold standard" for detection of bovine rotavirus in fecal samples, the sensitivity and specificity were found to be 87.8 and 73.3%, respectively. Latex agglutination compared with ELISA (the reference method) showed 100% sensitivity and 96.3% specificity, and when ELISA was compared with VI, the sensitivity was 84.8% and the specificity was 73.3%. Latex agglutination is easy to perform in a short time and does not require expensive equipment or skilled personnel, and the reagents have long shelf lives. These factors make the LAT suitable and highly efficient for use in a clinical laboratory as a rapid screening test for bovine rotavirus.

Animals↗
PubMed2005

Culture methods differ on the isolation of Salmonella enterica serotypes from naturally contaminated swine fecal samples.

Four culture methods (A, B, C, and D) were comparatively evaluated for their ability to isolate Salmonella enterica from pooled swine fecal samples (n = 100). None of the methods was able to isolate Salmonella from all positive samples. The relative sensitivity of the culture methods evaluated was 82%, 94%, 95%, and 78% for methods A, B, C, and D, respectively. The comparison of sensitivities showed that methods B and C performed significantly better (P < 0.05) than methods A and D. Although relative sensitivities of methods B and C were equal, from the 89 positive samples concomitantly detected by both, 35 (39.3%) had different serotypes (no match) isolated by each method. On the basis of the results of this study, it was concluded that culture methods differ on the isolation of S. enterica serotypes from naturally contaminated swine fecal samples. Depending on the objective(s) of investigations on the ecology and epidemiology of S. enterica in swine populations, a method or a combination of methods should be considered for more reliable results.

Animals↗
PubMed2004

Detection of K-ras gene mutation in fecal samples from elderly large intestinal cancer patients and its diagnostic significance.

AIM: To study the diagnostic significance of K-ras gene mutations in fecal samples from elderly patients with large intestinal cancer. METHODS: DNA was extracted in the fecal and tissue samples from 23 large intestinal cancer patients, 20 colonic adenomatoid polypus patients and 20 healthy subjects. The K-ras gene mutations at the first and second bases of codon 12 were detected by the allele specific mismatch method. RESULTS: The K-ras gene mutation was 56.52%(13/23) in the large intestinal cancer patients, which was notably higher than that in the normal subjects whose K-ras gene mutation was 5%(1/20) (chi (2)=12.93, P<0.001). There was no significant difference in comparison with that of colonic adenomatoid polypus patients whose K-ras gene mutation was 30%(6/12) (chi (2)=3.05, P>0.05). The K-ras gene mutation at the second base of codon 12 was 92.13%(12/13) in the large intestinal cancer patients. There was no significant difference between the detection rate of K-ras gene mutation in the fecal and tissue samples (chi (2)=9.35, P<0.01). CONCLUSION: Our results indicate that detection of the K-ras gene mutations in fecal samples provides a non-invasive diagnostic method for the elderly large intestinal cancer patients. Its significance in the early diagnosis of large intestinal cancer awaits further studies.

Aged↗
PubMed2006

Escherichia coli O157 and non-O157 Shiga toxin-producing Escherichia coli in fecal samples of finished pigs at slaughter in Switzerland.

Fecal samples from 630 slaughtered finisher pigs were examined by PCR to assess the shedding of Escherichia coli O157 (rfbE) and Shiga toxin-producing E. coli (STEC, stx). The proportion of positive samples was 7.5% for rfbE and 22% for stx. By colony hybridization, 31 E. coli O157 and 45 STEC strains were isolated, and these strains were further characterized by phenotypic and genotypic traits. Among E. coli O157 strains, 30 were sorbitol positive, 30 had an H type other than H7, and none harbored stx genes. Intimin (eae), enterohemolysin (ehxA), EAST1 (astA), and porcine A/E-associated protein (paa) were present in 10, 3, 26, and 6% of strains. Among them, one eae-gamma1-positive O157:H7 strain testing positive for ehxA and astA and two eae-alpha1-positive O157:H45 strains were classified as enteropathogenic E. coli (EPEC). The O157:H45 EPEC harbored the EAF plasmid and the bfpA gene, factors characteristic for typical EPEC. The isolated STEC strains (43 sorbitol positive) belonged to 11 O:H serotypes, including three previously reported in human STEC causing hemolytic uremic syndrome (O9:H-, O26:H-, and O103:H2). All but one strain harbored stx2e. The eae and ehxA genes, which are strongly correlated with human disease, were present in only one O103:H2 strain positive for stx1 and paa, whereas the astA gene was found more frequently (14 strains). High prevalence of STEC was found among finisher pigs, but according to the virulence factors the majority of these strains seem to be of low virulence.

Abattoirs↗
PubMed1997

Use of commercial enzyme immunoassays and immunomagnetic separation systems for detecting Escherichia coli O157 in bovine fecal samples.

A commercial enzyme immunoassay (EIA) (E. coli O157 Visual Immunoassay; Tecra Diagnostics) performed on enrichment cultures in modified Escherichia coli broth (mECn) was compared with immunomagnetic separation (IMS) (Dynabeads anti-E. coli O157; Dynal) performed on enrichment cultures in modified buffered peptone water (BPW-VCC) for the detection of E. coli O157 in bovine fecal samples. Tests on fecal suspensions inoculated with each of 12 different strains of E. coli O157 showed that both the EIA and IMS methods were 10- to 100-fold more sensitive than direct culture or enrichment subculture methods for detection of the organism. EIA and IMS were then compared for detection of E. coli O157 in bovine rectal swabs. For confirmation of positive EIA tests, a commercial system (Immunocapture System [ICS]; Tecra Diagnostics) was compared with IMS; both were performed on mECn enrichment cultures. Of 200 rectal swabs examined, 17 gave positive results in the EIA which were confirmed by both confirmation systems, 2 gave positive results in the EIA which were confirmed by IMS but not by ICS, and 1 gave a positive result in the EIA which was confirmed by ICS but not by IMS. Of these 20, 15 were also positive by the BPW-VCC-IMS culture system; a further 3 samples were positive by this culture system but gave a negative result in the EIA. Eight samples were negative by the BPW-VCC-IMS culture system but gave a positive result in the EIA which could not be confirmed by either confirmation system. Further examination of the eight unconfirmed EIA-positive samples yielded sorbitol-fermenting E. coli O157 from three samples. Of the remaining five cultures, four were positive in an EIA for verocytotoxins (VT) and two were positive in a cell culture assay for VT1. The remaining 170 samples were negative by both EIA and BPW-VCC-IMS. The Tecra EIA and IMS are both technically simple and sensitive methods for detecting E. coli O157 in bovine fecal samples. There was no statistically significant difference between the numbers of positives detected by the different assays (P = 0.29).

Animals↗
PubMed2003

Biochemical and physiological validation of a corticosteroid radioimmunoassay for plasma and fecal samples in oldfield mice (Peromyscus polionotus).

The measurement of fecal steroids provides an increasingly important noninvasive technique for assessing reproduction, environmental stress, and aggression in populations of captive and free-living animals. In this paper, we validated the corticosterone (CORT) 125I-radioimmunoassay (ICN Pharmaceuticals) for plasma and fecal samples in a small rodent species, the oldfield mouse (Peromyscus polionotus subgriseus). The biochemical validations indicated that the assays accurately measured CORT concentrations in the plasma and corticosteroid concentrations in the feces. Physiological validation demonstrated that: (1) blood samples collected within 3 min of disturbing an animal's cage represented "baseline" CORT concentrations, and (2) fecal corticosteroid concentrations collected over a 24-h period closely tracked plasma CORT concentrations approximately 4 h earlier. These results demonstrate that the plasma CORT and fecal corticosteroid assays are sensitive enough to detect biologically meaningful alterations in corticosteroid concentrations in oldfield mice.

Adrenal Cortex Hormones↗
PubMedDate not supplied

[Isolation of Cryptosporidium sp. oocysts from human fecal samples].

Experiments using two sequential discontinuous sucrose gradients, performed with 12%, 18%, 21% and 24% solutions, for the isolation of Cryptosporidium sp. oocysts from human fecal samples were undertaken. The sucrose gradients were centrifuged at 4000 rpm during 20 min. at 10 degrees C or room temperature. After that, 3 bands were observed. Oocysts were recovered mainly from the second band (75.5% after the first gradient, and 44.4% in the next). The two sequential discontinuous sucrose gradients would permit an efficient isolation of Cryptosporidium sp. oocysts from human fecal samples.

Animals↗
PubMed2001

Heminested multiplex reverse transcription-PCR for detection and differentiation of Norwalk-like virus genogroups 1 and 2 in fecal samples.

The present study describes a heminested multiplex reverse transcription (RT)-PCR assay which enables simultaneous detection and differentiation of Norwalk-like virus (NLV) genogroups from clinical fecal samples without the need to perform sequencing or hybridization. The assay developed was able to detect concentrations of fewer than 100 viral particles per 5 microl of clarified fecal extract and could differentiate the two genogroups with a specificity of 100%. Although the multiplex RT-PCR assay failed to detect NLV in about 3% of the fecal samples which were NLV positive by electron microscopy (EM), the assay was approximately six times more sensitive than EM for NLV detection.

Caliciviridae↗
PubMed1990

The detection of Giardia muris and Giardia lamblia cysts by immunofluorescence in animal tissues and fecal samples subjected to cycles of freezing and thawing.

The effects of freezing and thawing on the detection of selected Giardia spp. cysts were investigated using immunofluorescence, bright field microscopy, and low voltage scanning electron microscopy (SEM). Giardia muris cysts were obtained from either animal carcasses, fecal pellets, or isolated cyst preparations, whereas Giardia lamblia cysts were isolated from fecal samples. These samples were stained using an immunofluorescence technique after 1-3 freezing (-16 C) and thawing (20 C) cycles. Cysts were detected successfully by immunofluorescence in all samples. However, in those samples subjected to freeze-thawing, the cyst walls often became distorted and then were not detectable by bright field microscopy. Low voltage SEM demonstrated that the filaments in the distorted cyst wall underwent rearrangements of interfilament spacing. Quantitation of cyst recovery after freezing and thawing demonstrated that a substantial loss occurred after 1 cycle of alternating temperature when low concentrations of cysts were used, but not with high concentrations of cysts. Cyst recovery, after 3 freezing and thawing cycles, was dramatically lowered irrespective of the initial cyst concentration. These results demonstrated that immunofluorescence was an effective technique for the detection of Giardia spp. cysts in frozen samples and would suggest that freezing and thawing of fecal samples could prevent the detection of cysts when only bright field microscopy was employed.

Animals↗
PubMed1980

Incidence of salmonellae in fecal samples of production swine and swine at slaughter plants in the United States in 1978.

Nine swine slaughter plants and 19 swine production units were randomly selected for sampling from the six highest swine-producing states representing a total of 64% of the United States swine production. Three composites of 10 fresh swine fecal samples were obtained from each slaughter plant, representing three different farm sources of swine. Two composite fecal samples were collected from two different production pens from each production unit. Samples were analyzed for salmonellae. Isolated salmonellae were biochemically and serologically identified and tested for antibiotic susceptibility and resistance transfer ability. Salmonellae were recovered from swine at seven of the nine slaughter plants and 16 of the 27 composites of slaughter swine. Of the 19 production units, 3 had swine shedding salmonellae. Resistances found included streptomycin, tetracycline, and sulfadiazine. Of the 52 total isolates tested, 71% had some level of antibiotic resistance. Only 3 of 37 resistant isolated could transfer resistance under the conditions used.

Abattoirs↗
PubMed1992

The magnetic immuno polymerase chain reaction assay for direct detection of salmonellae in fecal samples.

Direct polymerase chain reaction (PCR)-based detection with fecal specimens is hampered by inhibitory compounds, such as bilirubin and bile salts. These fecal compounds showed significant inhibition of PCR at low concentrations (10 to 50 micrograms/ml). For direct PCR analysis, fecal samples must be diluted 500-fold to overcome inhibition. Therefore, the magnetic immuno PCR assay (MIPA), which combines immunomagnetic separation by using specific monoclonal antibodies and PCR, was used to directly detect salmonellae in feces from humans. Immunomagnetically extracted stool samples needed to be diluted only 10-fold when 1 microgram of T4 gene 32 protein was added to the PCR. The MIPA sensitivity obtained was 10(5) CFU/ml of feces. A panel of monoclonal antibodies specific for Salmonella serogroups A to E was used to extract salmonellae from clinical samples. MIPA detection of salmonellae occurred with 11 out of 14 stool samples stored at 4 degrees C for 2 months. MIPA detection of salmonellae in stool samples is a promising, fast method for detection and identification.

Antibodies, Monoclonal↗
PubMed1996

Modified technique to recover microsporidian spores in sodium acetate-acetic acid-formalin-fixed fecal samples by light microscopy and correlation with transmission electron microscopy.

Microsporidia are an emerging cause of significant disease, particularly in the immunocompromised host. Until recently, the diagnosis of enteric infections has required invasive sampling, the use of expensive technology, and considerable technological expertise. The purpose of the present study was to examine three modifications to the processing of fecal specimens for light microscopy (LM) examination for microsporidian spores: the use of pretreatment with potassium hydroxide, modified centrifugation conditions, and a modified staining technique. A sodium acetate-acetic acid-formalin-fixed fecal sample containing numerous microsporidian spores confirmed to be positive by transmission electron microscopy (TEM) was used in all studies performed. A simulation of a heavy to lightly infected individual was used. The results of LM were correlated with those of TEM. Duplicate smears were stained with Weber's modified trichrome and Giemsa (GS) stains. The stained slides were randomized and examined blindly by LM at x 625 and x 1,250 magnifications. A portion of the dilutions after centrifugation were fixed for TEM. The Weber modified trichrome stain performance rating was higher than the Giemsa stain rating because of ease of interpretation, and material stained with Weber modified trichrome stain required less examination time at a lower magnification. The number of positive smears and the quantity of spores detected were significantly higher following pretreatment of the sample with KOH. TEM was positive only when numerous spores were present, but the quality of the photomicrographs was superior after pretreatment with KOH. Pretreatment of sodium acetate-acetic acid-formalin-fixed fecal samples with 10% KOH and then a 5-min centrifugation time and staining with Weber modified trichrome stain provide for the excellent recovery of microsporidia in the routine diagnostic parasitology laboratory.

AIDS-Related Opportunistic Infections↗
PubMed1989

An improved method for oxidation of chromium(III) oxide-containing fecal samples by using sodium peroxide fusion.

A safer method of oxidation of Cr2O3-containing fecal samples from transit-time studies was developed using sodium peroxide to replace perchloric acid as the oxidizing agent. The percentage recovery of Cr2O3 with this method was compared with that of perchloric acid method for samples containing quantities of fecal ash and Cr2O3 typical of those from rodent transit-time studies. Both methods gave relatively constant percentage recoveries for Cr2O3 contents from 0.4 to 10 mg. Over this range, mean (+/- SD) percentage recoveries of Cr2O3 for sodium peroxide fusion and the perchloric acid method were 75.5 +/- 4.3 and 89.9 +/- 2.5, respectively. As long as percentage recovery is constant, the transit time as determined by calculation of the time of 80% excretion of the total recovered Cr2O3 is not affected. Sodium peroxide fusion provides a useful and safer alternative to perchloric acid oxidation in transit-time studies using Cr2O3 as a nonabsorbable marker.

Animals↗
PubMed2000

Quantification of different Eubacterium spp. in human fecal samples with species-specific 16S rRNA-targeted oligonucleotide probes.

Species-specific 16S rRNA-targeted, Cy3 (indocarbocyanine)-labeled oligonucleotide probes were designed and validated to quantify different Eubacterium species in human fecal samples. Probes were directed at Eubacterium barkeri, E. biforme, E. contortum, E. cylindroides (two probes), E. dolichum, E. hadrum, E. lentum, E. limosum, E. moniliforme, and E. ventriosum. The specificity of the probes was tested with the type strains and a range of common intestinal bacteria. With one exception, none of the probes showed cross-hybridization under stringent conditions. The species-specific probes were applied to fecal samples obtained from 12 healthy volunteers. E. biforme, E. cylindroides, E. hadrum, E. lentum, and E. ventriosum could be determined. All other Eubacterium species for which probes had been designed were under the detection limit of 10(7) cells g (dry weight) of feces(-1). The cell counts obtained are essentially in accordance with the literature data, which are based on colony counts. This shows that whole-cell in situ hybridization with species-specific probes is a valuable tool for the enumeration of Eubacterium species in feces.

Colony Count, Microbial↗
PubMedDate not supplied

Taenia saginata: polymerase chain reaction for taeniasis diagnosis in human fecal samples.

The taeniasis-cysticercosis complex is a zoonosis of great medical and economic importance where humans play an important role as the carrier of adult stage of Taenia solium and Taenia saginata. This paper describes PCR standardization that can be applied in human fecal samples for taeniasis diagnosis. DNA extraction was achieved with DNAzol reagent, after egg disruption with glass beads. DNA prepared from fecal specimens was first purified and PCR amplified generating fragments of 170 and 600 bp. The assay described herein provides an important tool for T. saginata identification in human fecal samples.

Animals↗
PubMed2001

PCR detection method of Clostridium scindens and C. hiranonis in human fecal samples.

Clostridium scindens and C. hiranonis have high bile acid 7alpha-dehydroxylating activity. Direct PCR and nested PCR with the specific primers for C. scindens and C. hiranonis were developed and tested for the detection of them in human fecal samples. Nested PCR detected C. scindens in all samples, but direct PCR detected it in 27 of 34 samples. Regarding C. hiranonis, nested PCR detected it in only 18 of 34 samples although nested PCR has a high level of sensitivity. Nested PCR was a specific and sensitive method for the detection of C. scindens and C. hiranonis in fecal samples.

Adult↗
PubMed2005

Multiplex real-time PCR assay using Scorpion probes and DNA capture for genotype-specific detection of Giardia lamblia on fecal samples.

Two major genotypic assemblages of Giardia lamblia infect humans; the epidemiologic significance of this phenomenon is poorly understood. We developed a single-vessel multiplex real-time PCR (qPCR) assay that genotypes Giardia infections into assemblages A and/or B directly from fecal samples. The assay utilized Scorpion probes that combined genotype-specific primers and probes for the 18S rRNA gene into the same molecule. The protocol was capable of detecting as few as 20 trophozoites per PCR on fecal DNA isolated using a commercial method or 1.25 trophozoites per PCR on fecal DNA isolated using a G. lamblia-specific oligonucleotide capture technique. The assay was specific for fecal specimens, with no amplification of the discordant genotype with the opposite Scorpion probe. When 97 clinical specimens from Bangladesh were used, the multiplex PCR assay detected 95% (21 of 22) of Giardia microscopy-positive specimens and 18% (13 of 74) of microscopy-negative specimens. Microscopy-negative and qPCR-positive specimens had higher average cycle threshold values than microscopy-positive and qPCR-positive specimens, suggesting that they represented true low-burden infections. Most (32 of 35) infections were assemblage B infections. This single-reaction multiplex qPCR assay distinguishes assemblage A Giardia infections from assemblage B infections directly on fecal samples and may aid epidemiologic investigation.

Animals↗