A Fixative for Intestinal Parasites Permitting the Use of Concentration and Permanent Staining Procedures

Yang, James P. S.; Scholten, T.

doi:10.1093/ajcp/67.3.300

Cited by 94 publications

(48 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While we did not perform a comparative study to determine differences in detection of pathogens from those matrices, the multiplexing approach using GPP worked well with both. There were inhibition challenges encountered while using Zn-PVA or formalin-fixed stools (data not shown), which is also an inherent challenge for nucleic acid-based testing (22)(23)(24).…”

Section: Discussionmentioning

confidence: 99%

Evaluation of Luminex xTAG Gastrointestinal Pathogen Analyte-Specific Reagents for High-Throughput, Simultaneous Detection of Bacteria, Viruses, and Parasites of Clinical and Public Health Importance

et al. 2013

View full text Add to dashboard Cite

Acute diarrheal disease (ADD) can be caused by a range of pathogens, including bacteria, viruses, and parasites. Conventional diagnostic methods, such as culture, microscopy, biochemical assays, and enzyme-linked immunosorbent assays (ELISA), are laborious and time-consuming and lack sensitivity. Combined, the array of tests performed on a single specimen can increase the turnaround time (TAT) significantly. We validated a 19plex laboratory-developed gastrointestinal pathogen panel (GPP) using Luminex xTAG analyte-specific reagents (ASRs) to simultaneously screen directly in fecal specimens for diarrhea-causing pathogens, including bacteria (Campylobacter jejuni, Salmonella spp., Shigella spp., enterotoxigenic Escherichia coli [ETEC], Shiga toxin-producing E. coli [STEC], E. coli O157:H7, Vibrio cholerae, Yersinia enterocolitica, and toxigenic Clostridium difficile), parasites (Giardia lamblia, Cryptosporidium spp., and Entamoeba histolytica), and viruses (norovirus GI and GII, adenovirus 40/41, and rotavirus A). Performance characteristics of GPP ASRs were determined using 48 reference isolates and 254 clinical specimens. Stool specimens from individuals with diarrhea were tested for pathogens using conventional and molecular methods. Using the predictive methods as standards, the sensitivities of the GPP ASRs were 100% for adenovirus 40/41, norovirus, rotavirus A, Vibrio cholerae, Yersinia enterocolitica, Entamoeba histolytica, Cryptosporidium spp., and E. coli O157:H7; 95% for Giardia lamblia; 94% for ETEC and STEC; 93% for Shigella spp.; 92% for Salmonella spp.; 91% for C. difficile A/B toxins; and 90% for Campylobacter jejuni. The overall comparative performance of the GPP ASRs with conventional methods in clinical samples was 94.5% (range, 90% to 97%), with 99% (99.0% to 99.9%) specificity. Implementation of the GPP ASRs enables our public health laboratory to offer highly sensitive and specific screening and identification of the major ADD-causing pathogens.

show abstract

Section: Discussionmentioning

confidence: 99%

Evaluation of Luminex xTAG Gastrointestinal Pathogen Analyte-Specific Reagents for High-Throughput, Simultaneous Detection of Bacteria, Viruses, and Parasites of Clinical and Public Health Importance

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Much better cytological results can be obtained by using a suitable fixative (see below) in combination with a permanent staining method. Concentration methods are not generally recommended for the recovery of D. fragilis, although trophozoites are sometimes found in concentrated stools (145).…”

Section: Microscopymentioning

confidence: 99%

“…Therefore, for optimal results, fecal specimens should be placed in a fixative immediately (145). Dobell (36) employed Schaudinn's fixative followed by staining with Heidenhain's iron-alum hematoxylin.…”

Section: Fixativesmentioning

confidence: 99%

Emerging from Obscurity: Biological, Clinical, and Diagnostic Aspects of Dientamoeba fragilis

2004

View full text Add to dashboard Cite

Ever since its first description in 1918, Dientamoeba fragilis has struggled to gain recognition as a significant pathogen. There is little justification for this neglect, however, since there exists a growing body of case reports from numerous countries around the world that have linked this protozoal parasite to clinical manifestations such as diarrhea, abdominal pain, flatulence, and anorexia. A number of studies have even incriminated D. fragilis as a cause of irritable bowel syndrome, allergic colitis, and diarrhea in human immunodeficiency virus patients. Although D. fragilis is most commonly identified using permanently stained fecal smears, recent advances in culturing techniques are simplifying as well as improving the ability of investigators to detect this organism. However, there are limitations in the use of cultures since they cannot be performed on fecal samples that have been fixed. Significant progress has been made in the biological classification of this organism, which originally was described as an ameba. Analyses of small-subunit rRNA gene sequences have clearly demonstrated its close relationship to Histomonas, and it is now known to be a trichomonad. How the organism is transmitted remains a mystery, although there is some evidence that D. fragilis might be transmitted via the ova of the pinworm, Enterobius vermicularis. Also, it remains to be answered whether the two distinct genotypes of D. fragilis recently identified represent organisms with differing virulence

show abstract

“…The most commonly used fixatives for stool preservation are either formalin or sodium acetate-acetic acid-formalin (SAF) (3,24,40). Of note, the FECT has some drawbacks.…”

mentioning

confidence: 99%

Comparison of the Flotac-400 Dual Technique and the Formalin-Ether Concentration Technique for Diagnosis of Human Intestinal Protozoon Infection

et al. 2011

View full text Add to dashboard Cite

There is a need for accurate diagnosis of intestinal parasite infections in humans, but currently available copromicroscopic techniques have shortcomings, such as low sensitivity. We compared the diagnostic accuracy of a further modified version of the recently developed Flotac technique with that of the widely used formalinether concentration technique (FECT) for the detection of intestinal protozoa in human stool samples. Formaldehyde-preserved stool samples from 108 individuals in Côte d'Ivoire were subjected to the Flotac-400 dual technique, using two different flotation solutions (FS), and to the FECT. Stool samples were examined according to computer-generated random lists by an experienced laboratory technician blinded for the results of each method. Both methods detected the same eight intestinal protozoon species. While the Flotac-400 dual technique (results from both FS combined) found higher prevalences of Entamoeba coli (77.8% versus 71.3%, P < 0.001), Blastocystis hominis (20.4% versus 13.0%, P ‫؍‬ 0.458), and Giardia intestinalis (8.3% versus 6.5%, P < 0.001), the FECT detected higher prevalences of Entamoeba histolytica/Entamoeba dispar (27.8% versus 20.4%, P ‫؍‬ 0.019) and four species of nonpathogenic intestinal protozoa. The diagnostic agreement between the two methods differed considerably depending on the intestinal protozoon investigated (Cohen's kappa measures; range, 0.01 to 0.46). Our study confirmed that the Flotac-400 dual technique can be utilized for the diagnosis of intestinal protozoon infections in humans. Since Flotac is a sensitive technique for the detection of soil-transmitted helminths and Schistosoma mansoni, it might become a viable copromicroscopic technique for the concurrent diagnosis of helminths and intestinal protozoon infections.Numerous protozoon species parasitize the intestine of humans, and some of them, e.g., Giardia intestinalis (synonyms: G. duodenalis and G. lamblia) and Entamoeba histolytica, cause a remarkable but presently not fully quantified disease burden, particularly in the humid tropics (26, 38). Epidemiologic studies and public health interventions, however, more often focus on helminths (e.g., Schistosoma mansoni, Ascaris lumbricoides, Trichuris trichiura, and hookworm) than intestinal protozoon infections (27). This may be partially explained by the fact that the microscopic diagnosis of intestinal protozoa is more difficult, hence requiring experienced, highly skilled technicians for correct identification and differentiation of intestinal protozoon cysts, and is more time consuming than the microscopic detection of helminth eggs in human stool samples.Various fecal egg count techniques, including stool concentration methods based on either flotation or sedimentation of parasitic elements, are employed for the diagnosis and epidemiologic surveillance of helminth and intestinal protozoon infections in humans and animals. By making use of centrifugal flotation or density gradient solutions, flotation techniques facilitate the floating of parasitic e...

show abstract

A Fixative for Intestinal Parasites Permitting the Use of Concentration and Permanent Staining Procedures

Cited by 94 publications

References 0 publications

Evaluation of Luminex xTAG Gastrointestinal Pathogen Analyte-Specific Reagents for High-Throughput, Simultaneous Detection of Bacteria, Viruses, and Parasites of Clinical and Public Health Importance

Evaluation of Luminex xTAG Gastrointestinal Pathogen Analyte-Specific Reagents for High-Throughput, Simultaneous Detection of Bacteria, Viruses, and Parasites of Clinical and Public Health Importance

Emerging from Obscurity: Biological, Clinical, and Diagnostic Aspects of Dientamoeba fragilis

Comparison of the Flotac-400 Dual Technique and the Formalin-Ether Concentration Technique for Diagnosis of Human Intestinal Protozoon Infection

Contact Info

Product

Resources

About