... Your 1- to 2-Year-Old Stool Test: H. Pylori Antigen KidsHealth > For Parents > Stool Test: H. Pylori Antigen A A A What's in this article? ... en español Muestra de materia fecal: antígeno de H. pylori What It Is Helicobacter pylori ( H. pylori ) bacteria ...
Amèndola, R; Doweck, J; Katz, J; Racca, J; Menendez, G; Schenone, L; Farìas, R; Barrantes, C; Quintanta, C; Zerbo, O; Kogan, Z; Valero, J; Bartellini, M A; Questa, U; Luna, P; Corti, R E
Nowadays technics for Helicobacter pylori detection in stools like culture, and PCR, are expensive and difficult to perform. The aim of this study was to evaluate ELISA test efficacy for detection of H. Pylori antigens in stools comparing this results with standarized technics like histology (Giemsa), ureasa test and UBT C 14. 26 patients were evaluated in this study, ages between 15-75 with upper gastrointestinal symptoms; all of them required gastroduodenal endoscopy, status H. Pylori was determined with methods upon mentioned. 24 hours after endoscopy H. Pylori antigens in stools with the technique Premier Platinum Htsa, Elisa were determined. The detection of H. Pylori antigens in stools accurately identified active H. Pylori infection. The performance characteristics of this non-invasive method was similar in sensibility and specificity to conventional tests.
Kodama, Masaaki; Murakami, Kazunari; Okimoto, Tadayoshi; Fukuda, Yoshihiro; Shimoyama, Tadashi; Okuda, Masumi; Kato, Chieko; Kobayashi, Intetsu; Fujioka, Toshio
AIM: To investigate the effects of proton pump inhibitor (PPI) treatment on stool antigen test using the TestMate pylori enzyme immunoassay. METHODS: This study assessed 28 patients [16 men and 12 women; mean age (63.1 ± 5.9) years; range, 25-84 years] who underwent stool antigen test and urea breath test (UBT) before and after PPI administration. RESULTS: Using the UBT as the standard, the sensitivity, specificity and agreement of the stool antigen test in all 28 patients were 95.2%, 71.4%, and 89.3%, respectively, before PPI administration, and 88.9%, 90.9%, and 89.3%, respectively, after PPI treatment. Mean UBT values were 23.98% ± 5.33% before and 16.19% ± 4.75% after PPI treatment and, in 15 patients treated for ≥ 4 wk, were significantly lower after than before 4 wk of PPI treatment (12.58% ± 4.49% vs 24.53% ± 8.53%, P = 0.048). The mean optical density (A450/630) ratios on the stool antigen test were 1.16 ± 0.20 before and 1.17 ± 0.24 after PPI treatment (P = 0.989), and were 1.02 ± 0.26 and 0.69 ± 0.28, respectively, in the group treated for > 4 wk (P = 0.099). CONCLUSION: The stool antigen test was equally sensitive to the UBT, making it a useful and reliable diagnostic method, even during PPI administration. PMID:22228969
... living in the intestines are necessary for normal digestion. If the intestines become infected with harmful bacteria ... which live there normally and are necessary for digestion. In a stool culture, lab technicians are most ...
... the stomach, intestines, or another part of the gastrointestinal system . A doctor may order a stool collection to ... of bacteria , viruses, or parasites that invade the gastrointestinal system digestive problems, such as the malabsorption of certain ...
Saidin, Syazwan; Yunus, Muhammad Hafiznur; Othman, Nurulhasanah; Lim, Yvonne Ai-Lian; Mohamed, Zeehaida; Zakaria, Nik Zairi; Noordin, Rahmah
Entamoeba histolytica infection remains a public health concern in developing countries. Early diagnosis of amoebiasis can avoid disease complications, thus this study was aimed at developing a test that can rapidly detect the parasite antigens in stool samples. Rabbits were individually immunized with recombinant pyruvate phosphate dikinase (rPPDK) and E. histolytica excretory-secretory antigens to produce polyclonal antibodies. A rapid dipstick test was produced using anti-rPPDK PAb lined on the dipstick as capture reagent and anti-EhESA PAb conjugated to colloidal gold as the detector reagent. Using E. histolytica-spiked in stool sample of a healthy individual, the detection limit of the dipstick test was found to be 1000 cells ml(-1). Meanwhile when rPPDK was spiked in the stool sample, the minimum concentration detected by the dipstick test was 0.1 μg ml(-1). The performances of the dipstick, commercial Techlab E. histolytica II enzyme-linked immunosorbent assays (ELISA) and real-time PCR were compared using 70 stool samples from patients infected with Entamoeba species (n = 45) and other intestinal pathogens (n = 25). When compared to real-time PCR, the diagnostic sensitivity of the dipstick for detection of E. histolytica was 65.4% (n = 17/26); while the diagnostic specificity when tested with stool samples containing other intestinal pathogens was 92% (23/25). In contrast, Techlab E. histolytica II ELISA detected 19.2% (5/26) of the E. histolytica-positive samples as compared to real-time PCR. The lateral flow dipstick test produced in this study enabled rapid detection of E. histolytica, thus it showed good potential to be further developed into a diagnostic tool for intestinal amoebiasis.
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 ...
İrvem, Arzu; Özdil, Kamil; Çalışkan, Zuhal; Yücel, Muhterem
Background: E. histolytica is among the common causes of acute gastroenteritis. The pathogenic species E. histolytica and the nonpathogenic species E. dispar cannot be morphologically differentiated, although correct identification of these protozoans is important for treatment and public health. In many laboratories, the screening of leukocytes, erythrocytes, amoebic cysts, trophozoites and parasite eggs is performed using Native-Lugol’s iodine for pre-diagnosis. Aims: In this study, we aimed to investigate the frequency of E. histolytica in stool samples collected from 788 patients residing in the Anatolian region of İstanbul who presented with gastrointestinal complaints. We used the information obtained to evaluate the effectiveness of microscopic examinations when used in combination with the E. histolytica adhesin antigen test. Study Design: Retrospective cross-sectional study Methods: Preparations of stool samples stained with Native-Lugol’s iodine were evaluated using the E. histolytica adhesin test and examined using standard light microscopy at ×40 magnification. Pearson’s Chi-square and Fisher’s exact tests were used for statistical analysis. Logistic regression analysis was used for multivariate analysis. Results: Of 788 samples, 38 (4.8%) were positive for E. histolytica adhesin antigens. When evaluated together with the presences of erythrocytes, leukocytes, cysts, and trophozoites, respectively, using logistic regression analysis, leukocyte positivity was significantly higher. The odds ratio of leukocyte positivity increased adhesin test-positivity by 2,530-fold (95% CI=1.01–6.330). Adhesin test-positivity was significant (p=0.047). Conclusion: In line with these findings, the consistency between the presence of cysts and erythrocytes and adhesin test-positivity was found to be highly significant, but that of higher levels of leukocytes was found to be discordant. It was concluded that leukocytes and trophozoites were easily misjudged
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. Methods: Stool and blood samples were collected from 162 apparently healthy participants (control) and 60 Type 2 diabetes mellitus (T2DM) patients. Results: 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. Conclusion: The performances of the detection kits were affected by various factors which should be taken into consideration. PMID:27736910
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 ...
... result. A test is considered negative if DNA markers common to colon cancer or precancerous polyps and signs of blood are ... result. A test is considered positive if DNA markers common to colon cancer or precancerous polyps or signs of blood are ...
... Your 1- to 2-Year-Old Stool Test: C. Difficile Toxin KidsHealth > For Parents > Stool Test: C. Difficile Toxin A A A What's in this ... Questions en español Muestra de materia fecal: toxina C. difficile What It Is A stool (feces) sample ...
... Your 1- to 2-Year-Old Stool Test: C. Difficile Toxin KidsHealth > For Parents > Stool Test: C. Difficile Toxin Print A A A What's in ... Questions en español Muestra de materia fecal: toxina C. difficile What It Is A stool (feces) sample ...
Robertson, Douglas J; Imperiale, Thomas F
Colorectal cancer (CRC) screening has been shown to reduce CRC incidence and mortality and is widely recommended. However, despite the demonstrated benefits of screening and ongoing efforts to improve screening rates, a large percentage of the population remains unscreened. Noninvasive stool based tests offer great opportunity to enhance screening uptake. The evidence supporting the use of both fecal immunochemical testing (FIT) and stool DNA (sDNA) has been growing rapidly and both tests are now commercially available for use. Other stool biomarkers (eg, RNA and protein based) are also actively under study both for use independently and as adjuncts to the currently available tests. This mini review provides current, state of the art knowledge about noninvasive stool based screening. It includes a more detailed examination of those tests currently in use (ie, FIT and sDNA) but also provides an overview of stool testing options under development (ie, protein and RNA).
... Development Infections Diseases & Conditions Pregnancy & Baby Nutrition & Fitness Emotions & Behavior School & Family Life First Aid & Safety Doctors & ... placed in tiny vials. Specific chemicals and a color developer are added. At the end of the ...
Calik, Zeki; Karamese, Murat; Acar, Osman; Aksak Karamese, Selina; Dicle, Yalcin; Albayrak, Fatih; Can, Serpil; Guvendi, Bulent; Turgut, Alpgiray; Cicek, Mustafa; Yazgi, Halil
Helicobacter pylori infection is usually acquired in early childhood and it can persist throughout life without antibiotic treatment. This study aimed to compare the accuracy of the noninvasive H. pylori Stool Antigen Test-applied on the stool samples with the invasive gold standart Rapid Urease Test-applied on the gastric biopy samples of patients with upper gastrointestinal complaints. After endoscopy, biopsy and stool specimens were taken in 122 patients. The infection was detected with rapid urease test which is accepted as gold standart test. Rapid, one-step H. pylori card test was applied to all patients stool specimens. In this study 106 of the 122 patients (86.8%) were positive for H. pylori infection, while 16 of the 122 patients (13.2%) were negative. H. pylori card test was negative in 13 of the 16 patients and was positive in 98 of the 106. The sensitivity, specifity, positive and negative predictive values were 92.45%, 81.25%, 97.02%, and 61.90%, respectively. H. pylori card test is rapid, easy, noninvasive and inexpensive methods for detection H. pylori infection. This test showed high sensitivity and specificity. Additionally, it may be a good alternative to invasive tests for the detection of H. pylori infections especially in children. PMID:26887240
Couturier, Brianne A.; Couturier, Marc Roger; Kalp, Kim J.
The STAT! Campy immunochromatographic assay for Campylobacter antigen was compared to culture for 500 clinical stool specimens. Antigen was detected in six culture-negative, PCR-positive specimens. C. upsaliensis, a pathogenic species that is traditionally difficult to recover in routine stool cultures, was detected in two of these culture-negative specimens. This study provides evidence that antigen testing may cross-react with at least one additional non-jejuni and -coli Campylobacter species that may be missed by routine culture for campylobacteriosis. PMID:23554192
Addiss, D G; Mathews, H M; Stewart, J M; Wahlquist, S P; Williams, R M; Finton, R J; Spencer, H C; Juranek, D D
The lack of a quick, simple, and inexpensive diagnostic test has limited the ability of public health officials to rapidly assess and control outbreaks of Giardia lamblia in child day-care centers. We evaluated the performance of a commercially available enzyme-linked immunosorbent assay (ELISA) for the detection of a G. lamblia-associated antigen in stool. Stool specimens were collected from the diapers of 426 children attending 20 day-care centers, fixed in 10% Formalin and polyvinyl alcohol, and examined by microscopy by Formalin concentration and trichrome staining techniques. Specimens were also tested visually and spectrophotometrically by ELISA. Of 99 tests positive by microscopy, 93 were visually positive by ELISA (sensitivity, 93.9%). Of 534 tests negative for G. lamblia by microscopy, 32 (6.0%) were ELISA positive. However, on the basis of examination of multiple specimens from the same child, none of these could be considered false-positive ELISAs; the specificity of the ELISA was therefore 100%. The sensitivity of both microscopy and ELISA improved as the number of specimens per child increased. An optical density value of greater than 0.040 was 98.0% sensitive and 100% specific for G. lamblia. This ELISA, which appeared to be more sensitive for G. lamblia than did microscopic examination of stool, should be useful as an epidemiologic tool, particularly in day-care settings, and may also have a role in confirming clinical diagnoses of giardiasis. PMID:1864930
Akhtar, Tasleem; Khan, Aamir Ghafoor; Ahmed, Israr; Nazli, Rubina; Haider, Jamila
Entamoeba histolytica (E. histolytica) produces an invasive disease called amoebiasis, which commonly produces diarrhea with or without blood in both children and adults, leading to high morbidity and mortality. Entamoeba dispar (E. Dispar) is a non invasive, non pathogenic organism. Both Entamoeba histolytica and Entamoeba Dispar look alike on microscopy and therefore cannot be differentiated unless checked on ELISA, PCR or other specific method. To calculate the actual prevalence of pathogenic amoebiasis in children by comparing the stool microscopy with ELISA stool antigen i.e. gold standard. Across sectional, comparative study. Children under five years in a community village Budhni, District Peshawar. A sample of 288 children aged <5 years were randomly selected. Information's were collected on the age and gender of the children. Fresh stool specimens were examined microscopically and with stool antigen kit of ELISA for detection of Entamoeba histolytica. The specificity and sensitivity of microscopic method was calculated against ELISA. Data was analyzed using statistical computer software package SPSS version 10.0. A total of 288 stool specimens were collected and examined for Entamoeba histolytica. Out of these 36(12.5%) stools were positive for E. histolyticaon microscopy while 14(4.9%) were positive on ELISA. Out of 14 ELISA positive samples, 10 samples were also positive on microscopy while 4 were ELISA positive but microscopy negative. About 22 samples, which were positive on microscopy were negative on ELISA indicating that these samples might have been of E. Dispar which is non pathogenic protozoa. The sensitivity and specificity of microscopic method was 71.4% and 90.5% respectively, as against stool antigen test. Actual prevalence of Entamoeba histolytica is low in the area. Stool ELISA was able to differentiate between pathogenic Entamoeba histolytica and the non-pathogenic Entamoeba dispar and thus can minimize unnecessary antiamoebic treatment in
Evans, D G; Evans, D J; Clegg, S
An enzyme-linked immunosorbent assay (ELISA) was employed to detect and quantitate the fimbrial colonization factor antigen (CFA/I) of enterotoxigenic Escherichia coli in stool specimens obtained from adult cases of diarrhea in which CFA/I-positive E. coli was the known causative agent. The inhibition method, or blocking technique, was used. In this method, a standardized dilution of human anti-CFA/I serum was preincubated with dilutions of stool extract before transfer to CFA/I-coated microtiter plate wells, and then ELISA was performed with alkaline phosphatase-conjugated anti-human immunoglobulin. CFA/I purified from E. coli strain H-10407 (O78:H11) was used. Acute-phase diarrheal stool specimens were found to contain approximately 3.0 mg of antigen (mean value) per g stool, whereas control (CFA/I-negative) specimens contained insignificant amounts (less than 0.03 mg/g) of antigen. Also, CFA/I was detected in culture fluids of CFA/I positive enterotoxigenic E. coli belonging to a variety of serotypes and was undetectable in similar preparations from P-strains (spontaneous CFA/I-negative derivatives) of the same test cultures. Equivalent results were obtained in ELISA tests by using bacterial cells taken from isolated colonies grown on CFA agar. These results indicate that the ELISA technique will be useful for the diagnosis of diarrhea caused by CFA/I-positive enterotoxigenic E. coli. PMID:7031075
... is not found in the stool. Note: Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your health care provider about the meaning of your specific test results.
Hassan, Ehsan H; Gerges, Shawkat S; Ahmed, Rehab; Mostafa, Zeinab M; Al-Hamid, Hager Abd; Abd El-Galil, Heba; Thabet, Suzan
Evidences supporting the association between H. pylori infection and chronic cholecystitis could be found by using direct culture or staining of H. pylori in gallbladder tissues as well as indirect techniques. Stool antigen test has been widely used due to its noninvasive nature. Various stool antigen tests were developed to detect H. pylori using an enzyme immunoassay (EIA) based on monoclonal or polyclonal antibodies This study evaluated the frequency of H. pylori antigen in stool samples of patients with chronic calcular cholecystitis as regard gall bladder histopathological changes. Fifty patients were included presented with symptomatic qholecystolithiasis recruited from the outpatient clinic of National Hepatology and Tropical Medicine Research Institute during 2014-2015. Full history and clinical examination and abdominal ultrasonography were performed. Stool samples were collected, prepared and examined for detection of H. pylori antigen. Cholecystectomy was done for all patients; 45 patients (90%) by laparoscopic Cholecystectomy and 5 patients (10%) by open surgery and removed gallbladders were submitted to pathology department for detection of H. pylori in tissue under microscope using Giemsa stain. The results showed that (82%) were females with mean age (42.6 +/- 1 years). The mean BMI was (29 + 7.2) H. pylori-specific antigen in stool samples was detected in 40% of patients and 38% were detected in patients; tissue, with significant correlation between H. pylori-specific antigen in stool and in tissue. Histopathological pictures infection in tissue were 68.4% mucosal erosions, 63.2% mucosal atrophy, 57.9% mucosal hyperplasia, 26.3% metaplasia, 42.1% musculosa hypertrophy, 26.3% fibrosis, but lymphoid aggregates were in 42.1% of cases.
Zhai, Rong-Lin; Xu, Fei; Zhang, Pei; Zhang, Wan-Li; Wang, Hui; Wang, Ji-Liang; Cai, Kai-Lin; Long, Yue-Ping; Lu, Xiao-Ming; Tao, Kai-Xiong; Wang, Guo-Bin
Abstract This meta-analysis was designed to evaluate the diagnostic performance of stool DNA testing for colorectal cancer (CRC) and compare the performance between single-gene and multiple-gene tests. MEDLINE, Cochrane, EMBASE databases were searched using keywords colorectal cancers, stool/fecal, sensitivity, specificity, DNA, and screening. Sensitivity analysis, quality assessments, and performance bias were performed for the included studies. Fifty-three studies were included in the analysis with a total sample size of 7524 patients. The studies were heterogeneous with regard to the genes being analyzed for fecal genetic biomarkers of CRC, as well as the laboratory methods being used for each assay. The sensitivity of the different assays ranged from 2% to 100% and the specificity ranged from 81% to 100%. The meta-analysis found that the pooled sensitivities for single- and multigene assays were 48.0% and 77.8%, respectively, while the pooled specificities were 97.0% and 92.7%. Receiver operator curves and diagnostic odds ratios showed no significant difference between both tests with regard to sensitivity or specificity. This meta-analysis revealed that using assays that evaluated multiple genes compared with single-gene assays did not increase the sensitivity or specificity of stool DNA testing in detecting CRC. PMID:26844449
Verkerke, Hans P; Hanbury, Blake; Siddique, Abdullah; Samie, Amidou; Haque, Rashidul; Herbein, Joel; Petri, William A
Rapid point-of-care detection of enteric protozoa in diarrheal stool is desirable in clinical and research settings to efficiently determine the etiology of diarrhea. We analyzed the ability of the third-generation E. histolytica Quik Chek assay developed by Techlab to detect amebic antigens in fecal samples collected from independent study populations in South Africa and Bangladesh. We compared the performance of this recently released rapid test to that of the commercially available ProSpecT Entamoeba histolytica microplate assay from Remel and the E. histolytica II enzyme-linked immunosorbent assay (ELISA) from Techlab, using real-time and nested-PCR for Entamoeba species to resolve any discrepant results. After discrepant resolution, The E. histolytica Quik Chek assay exhibited sensitivity and specificity compared to the E. histolytica II ELISA of 98.0% (95% confidence interval [CI], 92.9% to 99.8%) and 100% (95% CI, 99.0% to 100%), respectively. Compared to the ProSpecT microplate assay, the E. histolytica Quik Chek (Quik Chek) assay exhibited 97.0% sensitivity (95% CI, 91.5% to 99.4%) and 100% specificity (95% CI, 99.0% to 100%). Our results indicate that the Quik Chek is a robust assay for the specific detection of E. histolytica trophozoites in unfixed frozen clinical stool samples.
Solaymani-Mohammadi, Shahram; Rezaian, Mostafa; Babaei, Zahra; Rajabpour, Azam; Meamar, Ahmad R.; Pourbabai, Ahmad A.; Petri, William A.
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. PMID:16757634
Ihekweazu, Faith D.; Ajjarapu, Avanthi; Kellermayer, Richard
Goals 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. Procedures 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. Results 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. Conclusions 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. PMID:26663793
M’ikanatha, Nkuchia M.; Dettinger, Lisa A.; Perry, Amanda; Rogers, Paul; Reynolds, Stanley M.
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
Banach, David B; Francois, Jeannette; Blash, Stephanie; Patel, Gopi; Jenkins, Stephen G; LaBombardi, Vincent; Kreiswirth, Barry N; Srinivasan, Arjun; Calfee, David P
Active surveillance to identify asymptomatic carriers of carbapenem-resistant Enterobacteriaceae (CRE) is a recommended strategy for CRE control in healthcare facilities. Active surveillance using stool specimens tested for Clostridium difficile is a relatively low-cost strategy to detect CRE carriers. Further evaluation of this and other risk factor-based active surveillance strategies is warranted.
Prevalence of Entamoeba histolytica -like cysts compared to E. histolytica antigens detected by ELISA in the stools of 600 patients from three socioeconomic communities in the Metropolitan City of Lahore, Pakistan.
Alam, Muhammad Azhar; Maqbool, Azhar; Nazir, Muhammad Mudasser; Lateef, Muhammad; Khan, Muhammad Sarwar; Ahmed, Atif Nisar; Ziaullah, M; Lindsay, David S
Amoebiasis, caused by Entamoeba histolytica , has a worldwide distribution and is of public health significance in many developing countries. It has a fecal-oral transmission cycle and is most prevalent in developing countries in regions where substandard sanitary conditions exist due to poverty. Little is known about the epidemiology of E. histolytica infection and its presence in different socioeconomic communities in developing countries. We undertook the present study in the city of Lahore, Pakistan, and our prediction was that the prevalence of E. histolytica -like cysts and E. histolytica stool antigen would be lower in patients from upper socioeconomic levels than in individuals from middle or lower socioeconomic levels. We investigated the prevalence of E. histolytica in humans from 3 socioeconomic communities in territories of Lahore, Pakistan. Six hundred fecal samples were collected and examined using both microscopy (triple fecal test) to detect cysts of E. histolytica -like amoeba and ELISA (stool antigen ELISA) to demonstrate diagnostic stool antigens of E. histolytica . Samples were from individuals living under conditions deemed to be upper socioeconomic class (n = 287), middle socioeconomic class (n = 172), and lower socioeconomic class (n = 141). The total prevalence of positive samples was 22.5% (135/600) by triple test and 16.8% (101/600) by stool antigen ELISA in the 600 fecal samples. Statistically, significant (P < 0.05) differences in prevalence were seen between the 3 socioeconomic class groups. Forty-four (15.3%) and 32 (11.1%) of 287 in the fecal samples from the upper socioeconomic class were positive by triple test and by antigen ELISA, respectively. Thirty-nine (22.6%) and 29 (16.8%) of 172 in the fecal samples from the middle socioeconomic class were positive by the triple test and by antigen ELISA, respectively. Fifty-two (36.8%) and 40 (28.3%) of 141 in the fecal samples from the lower socioeconomic class were positive by the triple
Rosoff, J D; Sanders, C A; Sonnad, S S; De Lay, P R; Hadley, W K; Vincenzi, F F; Yajko, D M; O'Hanley, P D
A commercially available enzyme immunoassay for the diagnosis of giardiasis was evaluated in a clinical trial. The ProSpecT/Giardia diagnostic test (Alexon, Inc., Mountain View, Calif.) was compared with the standard ova and parasite (O&P) microscopic examination. Additionally, several widely used stool fixatives and a commonly used transport medium were assessed for compatibility with the immunoassay. A total of 325 stool specimens were collected and used to evaluate assay performance. Of those, 93 specimens were collected from symptomatic Giardia O&P-positive patients and 232 specimens were randomly collected from patients as part of a routine health screening procedure. All 93 Giardia O&P-positive stool specimens were strongly positive by visual and spectrophotometric examination using the immunoassay. Of the 232 randomly collected specimens, 16 were positive by O&P examination and immunoassay, 6 were negative by O&P examination but positive by immunoassay, and 1 was positive by O&P examination and negative by immunoassay. There was substantial supportive evidence that indicated that the six immunoassay-positive, O&P-negative specimens were true-positives. When these six specimens were accepted as true-positives, the immunoassay detected almost 30% more cases of Giardia infection than did O&P examination. Its sensitivity and specificity were 96 and 100%, respectively, while the sensitivity and specificity of O&P examination were 74 and 100%, respectively. The immunoassay also performed well on specimens treated with 10% neutral Formalin, sodium acetate-Formalin fixative, and Cary-Blair transport medium. However, the test was not compatible with polyvinyl alcohol-treated specimens. Overall, the ProSpecT/Giardia test was a sensitive, specific immunoassay which was easy to run and interpret. It offers a simple solution to traditional difficulties encountered in diagnosing Giardia infection.
Patrick, Mary; Gonzalez, Anthony; Akin, Joshua; Polage, Christopher R.; Wymore, Kate; Gillim-Ross, Laura; Xavier, Karen; Sadlowski, Jennifer; Monahan, Jan; Hurd, Sharon; Dahlberg, Suzanne; Jerris, Robert; Watson, Renee; Santovenia, Monica; Mitchell, David; Harrison, Cassandra; Tobin-D'Angelo, Melissa; DeMartino, Mary; Pentella, Michael; Razeq, Jafar; Leonard, Celere; Jung, Carrianne; Achong-Bowe, Ria; Evans, Yaaqobah; Jain, Damini; Juni, Billie; Leano, Fe; Robinson, Trisha; Smith, Kirk; Gittelman, Rachel M.; Garrigan, Charles; Nachamkin, Irving
The use of culture-independent diagnostic tests (CIDTs), such as stool antigen tests, as standalone tests for the detection of Campylobacter in stool is increasing. We conducted a prospective, multicenter study to evaluate the performance of stool antigen CIDTs compared to culture and PCR for Campylobacter detection. Between July and October 2010, we tested 2,767 stool specimens from patients with gastrointestinal illness with the following methods: four types of Campylobacter selective media, four commercial stool antigen assays, and a commercial PCR assay. Illnesses from which specimens were positive by one or more culture media or at least one CIDT and PCR were designated “cases.” A total of 95 specimens (3.4%) met the case definition. The stool antigen CIDTs ranged from 79.6% to 87.6% in sensitivity, 95.9 to 99.5% in specificity, and 41.3 to 84.3% in positive predictive value. Culture alone detected 80/89 (89.9% sensitivity) Campylobacter jejuni/Campylobacter coli-positive cases. Of the 209 noncases that were positive by at least one CIDT, only one (0.48%) was positive by all four stool antigen tests, and 73% were positive by just one stool antigen test. The questionable relevance of unconfirmed positive stool antigen CIDT results was supported by the finding that noncases were less likely than cases to have gastrointestinal symptoms. Thus, while the tests were convenient to use, the sensitivity, specificity, and positive predictive value of Campylobacter stool antigen tests were highly variable. Given the relatively low incidence of Campylobacter disease and the generally poor diagnostic test characteristics, this study calls into question the use of commercially available stool antigen CIDTs as standalone tests for direct detection of Campylobacter in stool. PMID:26962088
... products and services. Advertising & Sponsorship: Policy | Opportunities Stool Culture Share this page: Was this page helpful? Also known as: Bacterial Culture, stool; Feces Culture Formal name: Enteric Pathogens Culture, ...
Mateveke, K.; Makamure, B.; Ferrand, R. A.; Gomo, E.
SUMMARY OBJECTIVE: To evaluate the diagnostic performance of Xpert® MTB/RIF on stool samples from children with clinical suspicion of pulmonary tuberculosis (PTB) at primary care clinics. DESIGN: A cross-sectional diagnostic evaluation enrolling 5–16 year olds from whom one induced sputum (IS) sample was tested for microbiological TB confirmation. Results of a single stool sample tested using Xpert were compared against microbiologically confirmed TB, defined as a positive result on sputum microscopy and/or culture and/or IS Xpert. RESULTS: Of 222 children enrolled, 218 had complete microbiological results. The median age was 10.6 years (interquartile range 8–13). TB was microbiologically confirmed in 19/218 (8.7%) children. Of these, respectively 5 (26%), 9 (47%) and 15 (79%) were smear-, culture- and IS Xpert-positive. Stool Xpert was positive in 13/19 (68%) microbiologically confirmed cases and 4/199 (2%) microbiologically negative cases. Stool Xpert detected 76.9% (10/13) of human immunodeficiency virus (HIV) infected and 50% (3/6) of non-HIV-infected children with microbiologically confirmed TB (P = 0.241). CONCLUSION: Stool Xpert is a potential alternative screening test for children with suspected TB if sputum is unavailable. Strategies to optimise the diagnostic yield of stool Xpert assay need further study. PMID:28234079
Kim, Hyun Soo; Kim, Jae-Seok
We compared the results of an antigen test (ELISA) with those of polymerase chain reaction (PCR) for the detection of rotavirus and norovirus in stool specimens. Rotavirus and norovirus antigen-positive stool specimens were collected, and rotavirus and norovirus PCRs were performed on these specimens. Of the 325 rotavirus antigen-positive specimens, 200 were positive for both assays and 125 were PCR negative. Of 286 norovirus antigen-positive specimens, 51 were PCR negative. Comparison of the lower limit of detection showed that rotavirus PCR was 16 times more sensitive and norovirus PCR was over 4,000 times more sensitive than the ELISA. Discrepant results between ELISA and PCR were common, and the possibility of false-positive and false-negative results should be considered with rotavirus and norovirus assays.
... absorption of nutrients ( malabsorption ) or too much gas (flatulence). Considerations Most causes of floating stools are harmless. ... Elsevier Saunders; 2016:chap 140. Read More Gas - flatulence Malabsorption Review Date 5/11/2016 Updated by: ...
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
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
... descriptors for describing stool consistency: Type 1: Separate hard lumps, like nuts. Type 2: Sausage-shaped but lumpy. Type 3: Like a sausage or snake but with cracks on its surface. Type 4: Like a sausage or snake, smooth and soft. ...
Prince, Mark; Lester, Lynn; Chiniwala, Rupal; Berger, Barry
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
Prostate-specific antigen; Prostate cancer screening test; PSA ... special steps are needed to prepare for this test. ... Reasons for a PSA test: This test may be done to screen for prostate cancer. It is also used to follow people after prostate cancer ...
Feghoul, Linda; Salmona, Maud; Cherot, Janine; Fahd, Mony; Dalle, Jean-Hugues; Vachon, Carole; Perrod, Aurélie; Bourgeois, Philippe; Scieux, Catherine; Baruchel, André; Simon, François
Sensitive molecular assays have greatly improved the diagnosis of viral gastroenteritis. However, the proper preparation of stool samples for clinical testing remains an issue. bioMérieux has developed a stool preprocessing device (SPD) that includes a spoon for calibrated sampling and a vial containing buffer, glass beads, and two filters. The resulting stool filtrate is used for nucleic acid extraction. The purpose of this study was to evaluate the performance of the SPD for the quantification of human adenovirus (HAdV) DNA in stool samples collected from hematopoietic stem cell transplant (HSCT) recipients. HAdV DNA was quantified with the Adenovirus R-gene kit. The suitability of the device to reproducibly quantify HAdV DNA in stools using different extraction platforms (easyMAG and QIAsymphony) was determined using archived HAdV-positive stool samples. Coefficients of variation of HAdV DNA quantifications ranged from 1.79% to 1.83%, and no difference in quantification was observed between the two extraction systems. The HAdV DNA limit of quantification using the SPD was 3.75 log10 copies/g of stool. HAdV DNA quantification using the SPD was then compared to that of the routine preprocessing technique on 75 fresh stool samples collected prospectively from pediatric HSCT recipients at risk for HAdV infections. Thirty-eight samples were HAdV DNA positive with both the SPD and routine preprocessing methods. HAdV DNA loads were on average 1.14-log10 copies/g of stool higher with the SPD (P < 0.0001) than with routine methods. This new device enabled a standardized preparation of stool samples in <5 min and a reproducible and sensitive quantification of HAdV DNA. The use of the SPD for the detection of other gastrointestinal infections warrants further evaluation. PMID:26763967
Feghoul, Linda; Salmona, Maud; Cherot, Janine; Fahd, Mony; Dalle, Jean-Hugues; Vachon, Carole; Perrod, Aurélie; Bourgeois, Philippe; Scieux, Catherine; Baruchel, André; Simon, François; LeGoff, Jérôme
Sensitive molecular assays have greatly improved the diagnosis of viral gastroenteritis. However, the proper preparation of stool samples for clinical testing remains an issue. bioMérieux has developed a stool preprocessing device (SPD) that includes a spoon for calibrated sampling and a vial containing buffer, glass beads, and two filters. The resulting stool filtrate is used for nucleic acid extraction. The purpose of this study was to evaluate the performance of the SPD for the quantification of human adenovirus (HAdV) DNA in stool samples collected from hematopoietic stem cell transplant (HSCT) recipients. HAdV DNA was quantified with the Adenovirus R-gene kit. The suitability of the device to reproducibly quantify HAdV DNA in stools using different extraction platforms (easyMAG and QIAsymphony) was determined using archived HAdV-positive stool samples. Coefficients of variation of HAdV DNA quantifications ranged from 1.79% to 1.83%, and no difference in quantification was observed between the two extraction systems. The HAdV DNA limit of quantification using the SPD was 3.75 log10copies/g of stool. HAdV DNA quantification using the SPD was then compared to that of the routine preprocessing technique on 75 fresh stool samples collected prospectively from pediatric HSCT recipients at risk for HAdV infections. Thirty-eight samples were HAdV DNA positive with both the SPD and routine preprocessing methods. HAdV DNA loads were on average 1.14-log10copies/g of stool higher with the SPD (P< 0.0001) than with routine methods. This new device enabled a standardized preparation of stool samples in <5 min and a reproducible and sensitive quantification of HAdV DNA. The use of the SPD for the detection of other gastrointestinal infections warrants further evaluation.
... After 48 to 72 hours the site of injection is evaluated by a physician. If a positive reaction occurs (the test site is inflamed), the person has been exposed to the aspergillus mold and is at risk for developing aspergillosis.
... gelatin will clear. How to Prepare for the Test Your health care provider will provide you with the supplies needed to collect the stool. Why the Test is Performed These tests are simple ways of ...
Hjelt, K. )
The fractional folic acid absorption (FAFol) was determined in 66 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 16.8 years (mean 6.3 years). The test dose was administered orally and consisted of 50 micrograms of (3H)folic acid (monoglutamate) (approximately 20 muCi), carmine powder, and 2 mg 51CrCl3 (approximately 1.25 muCi) as the unabsorbable tracer. The whole-body radiation given to a 1-year-old child averaged 4.8 mrad only. The stool and napkin contents were collected and homogenized by the addition of 300 ml chromium sulfuric acid. A 300-ml sample of the homogenized stool and napkin contents, as well as 300 ml chromium sulfuric acid (75% vol/vol) containing the standards, were counted for the content of 51Cr in a broad-based well counter. The quantity of (3H)folic acid was determined by liquid scintillation, after duplicate distillation. Estimated by SSST, the FAFol, which employs the stool with the highest content of 51Cr corresponding to the most carmine-colored stool, correlated closely with the FAFol based on complete stool collection (r = 0.96, n = 39, p less than 0.0001). The reproducibility of FAFol determined by SSST was assessed from repeated tests in 18 patients. For a mean of 81%, the SD was 4.6%, which corresponded to a coefficient of variation of 5.7%.
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 by 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.
Moura, H; Sodre, F C; Bornay-Llinares, F J; Leitch, G J; Navin, T; Wahlquist, S; Bryan, R; Meseguer, I; Visvesvara, G S
Of the several microsporidia that infect humans, Enterocytozoon bieneusi is known to cause a gastrointestinal disease whereas Encephalitozoon intestinalis causes both a disseminated and an intestinal disease. Although several different staining techniques, including the chromotrope technique and its modifications, Uvitex 2B, and the quick-hot Gram-chromotrope procedure, detect microsporidian spores in fecal smears and other clinical samples, they do not identify the species of microsporidia. A need for an easily performed test therefore exists. We reevaluated 120 stool samples that had been found positive for microsporidia previously, using the quick-hot Gram-chromotrope technique, and segregated them into two groups on the basis of spore size. We also screened the smears by immunofluorescence microscopy, using a polyclonal rabbit anti-E. intestinalis serum at a dilution of 1:400. Spores in 29 (24.1%) of the 120 samples fluoresced brightly, indicating that they were E. intestinalis spores. No intense background or cross-reactivity with bacteria, yeasts, or other structures in the stool samples was seen. Additionally, the numbers of spores that fluoresced in seven of these samples were substantially smaller than the numbers of spores that were present in the stained smears, indicating that these samples were probably derived from patients with mixed infections of Enterocytozoon bieneusi and E. intestinalis. Because a 1:400 dilution of this serum does not react with culture-grown Encephalitozoon hellem, Encephalitozoon cuniculi, or Vittaforma corneae or with Enterocytozoon bieneusi spores in feces, we concluded that an immunofluorescence test using this serum is a good alternative for the specific identification of E. intestinalis infections.
Dienstag, J L; Krugman, S; Wong, D C; Purcell, R H
To compare serological tests for antibody to hepatitis A antigen (anti-HA), we tested 15 paired serum specimens, submitted under code, from individuals infected with the MS-1 strain of hepatitis A virus. Immune electron microscopy (IEM), immune adherence hemagglutination (IAHA), and solid-phase radioimmunoassay (RIA) tests for anti-HA were performed with hepatitis A antigen (HA Ag) derived from human stool; results were also compared with previously reported titers determined by IAHA with HA Ag derived from marmoset liver. Antibody titers (IAHA and RIA) and ratings (IEM) determined with stool-derived HA Ag compared favorably, and a seroresponse to HA Ag was detected by all three methods for every serum pair tested. Differences in titers were noted between IAHA tests with liver-derived and with stool-derived HA Ag, but the discrepancies could be accounted for by differences in test technique. The agreement found in this study among the three techniques was quite good and confirms the specificity and sensitivity of tests for anti-HA that are done with stool-derived HA-Ag. PMID:186409
Greter, Helena; Krauth, Stefanie J.; Ngandolo, Bongo N. R.; Alfaroukh, Idriss O.; Zinsstag, Jakob; Utzinger, Jürg
On the shores of Lake Chad, schistosomiasis among mobile pastoralists was investigated in a field laboratory. Point-of-care circulating cathodic antigen (POC-CCA) cassette test, reagent strip, and filtration were conducted on urine samples. Fresh stool samples were subjected to the Kato-Katz technique, and fixed samples were examined with an ether-concentration method at a reference laboratory. POC-CCA urine cassette tests revealed a Schistosoma mansoni prevalence of 6.9%, compared with only 0.5% by stool microscopy. Three pregnant women with otherwise negative urine and stool testing had positive POC-CCA. This observation raises concern of cross-reactivity in pregnancy. Hence, two pregnant women in Switzerland with no history of schistosomiasis were subjected to POC-CCA and one tested positive. Our data suggest that POC-CCA can be performed under extreme Sahelian conditions (e.g., temperatures > 40°C), and it is more sensitive than stool microscopy for S. mansoni diagnosis. However, potential cross-reactivity in pregnancy needs further investigation. PMID:26556831
Greter, Helena; Krauth, Stefanie J; Ngandolo, Bongo N R; Alfaroukh, Idriss O; Zinsstag, Jakob; Utzinger, Jürg
On the shores of Lake Chad, schistosomiasis among mobile pastoralists was investigated in a field laboratory. Point-of-care circulating cathodic antigen (POC-CCA) cassette test, reagent strip, and filtration were conducted on urine samples. Fresh stool samples were subjected to the Kato-Katz technique, and fixed samples were examined with an ether-concentration method at a reference laboratory. POC-CCA urine cassette tests revealed a Schistosoma mansoni prevalence of 6.9%, compared with only 0.5% by stool microscopy. Three pregnant women with otherwise negative urine and stool testing had positive POC-CCA. This observation raises concern of cross-reactivity in pregnancy. Hence, two pregnant women in Switzerland with no history of schistosomiasis were subjected to POC-CCA and one tested positive. Our data suggest that POC-CCA can be performed under extreme Sahelian conditions (e.g., temperatures > 40°C), and it is more sensitive than stool microscopy for S. mansoni diagnosis. However, potential cross-reactivity in pregnancy needs further investigation.
... smelling stools also have normal causes, such as diet changes. Causes Causes may include: Celiac disease - sprue Crohn ... of diet have you eaten recently? Does a change in your diet make the smell worse or better? What other ...
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
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.
Jung, Hwa S; Jung, Hyung-Shik
Many jobs and activities in people's daily lives have them in squatting postures. Jobs such as housekeeping, farming and welding require various squatting activities. It is speculated that prolonged squatting without any type of supporting stool would gradually and eventually impose musculoskeletal injuries on workers. This study aims to examine the proper height of the stool according to the position of working materials for the squatting worker. A total of 40 male and female college students and 10 female farmers participated in the experiment to find the proper stool height. Student participants were asked to sit and work in three different positions: floor level of 50 mm; ankle level of 200 mm; and knee level of 400 mm. They were then provided with stools of various heights and asked to maintain a squatting work posture. For each working position, they were asked to write down their thoughts on a preferred stool height. A Likert summated rating method as well as pairwise ranking test was applied to evaluate user preference for provided stools under conditions of different working positions. Under a similar experimental procedure, female farmers were asked to indicate their body part discomfort (BPD) on a body chart before and after performing the work. Statistical analysis showed that comparable results were found from both evaluation measures. When working position is below 50 mm, the proper stool height is 100 or should not be higher than 150 mm. When working position is 200 mm, the proper stool height is 150 mm. When working position is 400 mm, the proper stool height is 200 mm. Thus, it is strongly recommended to use proper height of stools with corresponding working position. Moreover, a wearable chair prototype was designed so that workers in a squatting posture do not have to carry and move the stool from one place to another. This stool should ultimately help to relieve physical stress and hence promote the health of squatting workers. This study sought
Sorgho, Hermann; Bahgat, Mahmoud; Poda, Jean-Noel; Song, Wenjian; Kirsten, Christa; Doenhoff, Michael J; Zongo, Issaka; Ouédraogo, Jean-Bosco; Ruppel, Andreas
The performance of indirect haemagglutination assays (IHA), enzyme-linked immunosorbent assays (ELISA) and indirect immunofluorescent antibody tests (IFAT) were compared with 450 sera from a Schistosoma mansoni-endemic area in Burkina Faso. All participants in this survey provided at least one sample each of stool, urine and serum. From those with an egg-negative Kato-Katz thick smear, a second stool sample was examined. IHA was based on either extracts of adult S. mansoni worms (SmIHA) or S. japonicum egg antigen (SjIHA). For ELISA, three antigen preparations were used, namely: (i) soluble S. mansoni adult worm antigens (SWAP); (ii) soluble S. mansoni egg antigens (SEA); and (iii) a cationic exchange fraction of S. mansoni eggs (CEF6). IFAT was performed with S. mansoni male worm sections. Among the egg-excretors, the sensitivity of ELISA was high and egg antigens performed slightly better (SEA, 96%; CEF6, 97%) than worm antigen (94%). Sensitivity of IHA was satisfactory with homologous (Sm, >85%), but not heterologous (Sj, 56%) parasite antigen. In IFAT, the parenchyma-associated fluorescence showed high sensitivity (95%), but gut-associated fluorescence, which is known to be a sensitive diagnostic marker for schistosome-infected European travelers, was observed only in 76% of a sub-sample of 100 of the endemic sera. Among sera from egg-negative individuals, many gave positive reactions in several or all of the tests employed. These reactions (formally "false positive") are considered to represent true infections, since chemotherapy had not yet been delivered to this population. For the purpose of further surveys in Burkina Faso or other resource-poor settings, we suggest IHA as an accurate diagnostic test and propose to further improve its performance by including egg rather than worm antigens.
... C diff antigen; GDH Formal name: Clostridium difficile Culture; C. difficile Toxin, A and B; C. difficile Cytotoxin Assay; Glutamate Dehydrogenase Test Related tests: Stool Culture ; O&P At a Glance Test Sample The ...
Quinlan, P T; Lockton, S; Irwin, J; Lucas, A L
"Constipation" and "hard stools" are associated with formula feeding of both term and preterm infants and, in the latter, can lead to life-threatening complications. This study tested the hypothesis that stool hardness is related to excretion of fatty acid (FA) soaps in term infants, and in the extreme to milk bolus obstruction in premature infants. Stools (n = 44) were collected from 20 formula-fed and 10 breast-fed infants aged 6 weeks and were classified using visual charts for stool hardness on a 5-point scale (1, watery; 5, hard). Stools were analysed for nitrogen, minerals, and lipid, the latter divided between the soap and nonsoap fractions. We explored the relationship between stool hardness or solids content and stool constituents, relative to both wet and dry weight. Calcium and FA soaps were the dominant factors significantly related to stool solids and hardness score across the breast- and formula-fed groups. An 8% increase in stool dry weight FA soap content corresponded to a 1-point change in stool hardness score. Stools from formula-fed infants had a higher solids content and were classified as significantly harder than those from breast-fed infants (hardness scores, 4.0 +/- 0.5 versus 2.6 +/- 0.7, mean +/- SD) and on both a wet- and dry-weight basis contained severalfold higher levels of minerals and lipid and considerably less carbohydrate. Differences in lipids between formula- and breast-fed infants' stools were due almost entirely to FAs (mainly C16:0 and C18:0) excreted as soaps (27.7 +/- 7.5% compared to 3.1 +/- 4.1% of dry weight), suggesting the groups differed markedly in their handling of saturated FAs. An inspissated stool sample from a premature infant requiring surgical disempaction of an obstructed small intestine was found to be enriched in FA and calcium relative to the preterm formula. FA soaps, predominantly saturated, accounted for one third of the stool dry weight. These data support the hypothesis that calcium FA soaps are
... prostate cancer recurrence. However, a single elevated PSA measurement in a patient who has a history of ... than with BPH . One recently approved test combines measurement of a form of pro-PSA called [-2] ...
... Stool Form Scale Type Description Type 1 Separate hard lumps, like nuts Image Type 2 Sausage-shaped but lumpy Type 3 Like a sausage or snake but with cracks on its surface Type 4 Like a sausage or snake, smooth and soft ...
... to worry Yesterday, my stool color was bright green. Should I be concerned? Answers from Michael F. ... of colors. All shades of brown and even green are considered normal. Only rarely does stool color ...
Middleton, P J; Petric, M; Hewitt, C M; Szymanski, M T; Tam, J S
A moderatley sensitive, rapid, and economical test scheme for the detection of infantile gastroenteritis virus (IGV) in stool or antibody in serum has been developed and evaluated. The test scheme with minor modifications was an adaptation of a counter-immunoelectro-osmophoresis system we once used for the detection of hepatitis B antigen. Large numbers of stool samples may be screened during half a working day for the presence of IGV using reference antiserum to IGV prepared in guinea-pigs. Serological studies of a diagnostic but not epidemiological nature may also be performed with equal facility by this same test scheme using highly purified IGV antigen derived from stool.
Tchuem Tchuenté, Louis-Albert; Kueté Fouodo, Césaire Joris; Kamwa Ngassam, Romuald Isaka; Sumo, Laurentine; Dongmo Noumedem, Calvine; Kenfack, Christian Mérimé; Gipwe, Nestor Feussom; Nana, Esther Dankoni; Stothard, J. Russell; Rollinson, David
Background The Kato-Katz is the most common diagnostic method for Schistosoma mansoni infection. However, the day-to-day variability in host egg-excretion and its low detection sensitivity are major limits for its use in low transmission zones and after widespread chemotherapy. We evaluated the accuracy of circulating cathodic antigen (CCA) urine-assay as a diagnostic tool of S. mansoni. In comparison, a low sensitive CCA test (CCA-L) was assessed. Methodology The study was conducted in three settings: two foci with single S. mansoni infections (settings A and B), and one mixed S. mansoni – S. haematobium focus (setting C). Stool and urine samples were collected from school-children on three consecutive days. Triplicate Kato-Katz readings were performed per stool sample. Each urine sample was tested with one CCA and only the first urine sample was subjected to CCA-L. Urine samples were also examined for S. haematobium eggs using the filtration method and for microhaematuria using urine reagent strips. Overall, 625 children provided three stool and three urine samples. Principal Findings Considering nine Kato-Katz thick smears as ‘reference’ diagnostic test, the prevalence of S. mansoni was 36.2%, 71.8% and 64.0% in settings A, B and C, respectively. The prevalence of S. haematobium in setting C was 12.0%. The sensitivities of single Kato-Katz, CCA and CCA-L from the first stool or urine samples were 58%, 82% and 46% in setting A, 56.8%, 82.4% and 68.8% in setting B, and 49.0%, 87.7% and 55.5% in setting C. The respective specificities were 100%, 64.7% and 100%; 100%, 62.3% and 91.3%; and 100%, 42.5% and 92.0%. Mixed infection with S. haematobium did not influence the CCA test results for S. mansoni diagnosis. Conclusions/Significance Urine CCA revealed higher sensitivity than CCA-L and triplicate Kato-Katz, and produced similar prevalence as nine Kato-Katz. It seems an attractive method for S. mansoni diagnosis. PMID:22860148
Nalintya, Elizabeth; Kiggundu, Reuben; Meya, David
Over the last decade, an upsurge in both the frequency and severity of fungal infections due to the HIV/AIDS epidemic and the use of immunosuppressive therapy has occurred. Even diagnostic methods like culture and microscopy, which have low sensitivity and longer turn-around-times are not widely available, leading to delays in timely antifungal therapy and detrimental patient outcomes. The evolution of cryptococcal antigen (CrAg) testing to develop inexpensive and more sensitive methods to detect cryptococcal antigen is significant. These newer tests employ immunoassays as part of point-of-care platforms, which do not require complex laboratory infrastructure and they have the potential to detect early disease and reduce time to diagnosis of cryptococcal infection. Advocacy for widely available and efficacious life-saving antifungal treatment should be the only remaining challenge.
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tumor-associated antigen immunological test system... SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Tumor Associated Antigen immunological Test Systems § 866.6010 Tumor-associated antigen immunological test system. (a) Identification....
Williamson, E; Oliver, D; Johnson, E; Foot, A; Marks, D; Warnock, D
Aims—To assess the clinical usefulness of a commercial aspergillus antigen enzyme linked immunosorbent assay (ELISA) in the diagnosis of invasive aspergillosis (IA) in bone marrow transplant recipients, and to compare it with a commercial latex agglutination (LA) test. Methods—In total, 2026 serum samples from 104 bone marrow transplant recipients were tested. These comprised 67 sera from seven patients who had died with confirmed IA, 268 sera from nine patients who had died with suspected IA, and 1691 sera from 88 patients with no clinical, radiological, or microbiological signs of IA. Results—The ELISA was more sensitive than the LA test. All patients who were ELISA positive were also LA positive, and a positive LA result never preceded a positive ELISA. Twelve of 16 patients with confirmed or suspected IA were ELISA positive on two or more occasions, compared with 10 of 15 who were LA positive. ELISA was positive before LA in five patients (range, 2–14 days), and became positive on the same day in the remainder. Aspergillus antigen was detected by ELISA a median of 15 days before death (range, 4–233). Clinical and/or radiological evidence of IA was noted in all patients, and a positive ELISA was never the sole criterion for introduction of antifungal treatment. Two samples (one from each of two patients without IA) gave false positive results. Conclusions—The aspergillus ELISA is a specific indicator of invasive aspergillosis if the criterion of two positive samples is required to confirm the diagnosis. However, the test is insufficiently sensitive to diagnose aspergillosis before other symptoms or signs are apparent, and hence is unlikely to lead to earlier initiation of antifungal treatment. It is therefore unsuitable for screening of asymptomatic patients at risk of invasive aspergillosis, but does have a useful role in confirming the diagnosis in symptomatic patients. Key Words: invasive aspergillosis • aspergillus antigen • Platelia enzyme
Ochodo, Eleanor A; Gopalakrishna, Gowri; Spek, Bea; Reitsma, Johannes B; van Lieshout, Lisette; Polman, Katja; Lamberton, Poppy; Bossuyt, Patrick Mm; Leeflang, Mariska Mg
Background Point-of-care (POC) tests for diagnosing schistosomiasis include tests based on circulating antigen detection and urine reagent strip tests. If they had sufficient diagnostic accuracy they could replace conventional microscopy as they provide a quicker answer and are easier to use. Objectives To summarise the diagnostic accuracy of: a) urine reagent strip tests in detecting active Schistosoma haematobium infection, with microscopy as the reference standard; and b) circulating antigen tests for detecting active Schistosoma infection in geographical regions endemic for Schistosoma mansoni or S. haematobium or both, with microscopy as the reference standard. Search methods We searched the electronic databases MEDLINE, EMBASE, BIOSIS, MEDION, and Health Technology Assessment (HTA) without language restriction up to 30 June 2014. Selection criteria We included studies that used microscopy as the reference standard: for S. haematobium, microscopy of urine prepared by filtration, centrifugation, or sedimentation methods; and for S. mansoni, microscopy of stool by Kato-Katz thick smear. We included studies on participants residing in endemic areas only. Data collection and analysis Two review authors independently extracted data, assessed quality of the data using QUADAS-2, and performed meta-analysis where appropriate. Using the variability of test thresholds, we used the hierarchical summary receiver operating characteristic (HSROC) model for all eligible tests (except the circulating cathodic antigen (CCA) POC for S. mansoni, where the bivariate random-effects model was more appropriate). We investigated heterogeneity, and carried out indirect comparisons where data were sufficient. Results for sensitivity and specificity are presented as percentages with 95% confidence intervals (CI). Main results We included 90 studies; 88 from field settings in Africa. The median S. haematobium infection prevalence was 41% (range 1% to 89%) and 36% for S. mansoni (range 8
Bruijnesteijn van Coppenraet, L E S; Wallinga, J A; Ruijs, G J H M; Bruins, M J; Verweij, J J
Molecular detection of gastrointestinal protozoa is more sensitive and more specific than microscopy but, to date, has not routinely replaced time-consuming microscopic analysis. Two internally controlled real-time PCR assays for the combined detection of Entamoeba histolytica, Giardia lamblia, Cryptosporidium spp. and Dientamoeba fragilis in single faecal samples were compared with Triple Faeces Test (TFT) microscopy results from 397 patient samples. Additionally, an algorithm for complete parasitological diagnosis was created. Real-time PCR revealed 152 (38.3%) positive cases, 18 of which were double infections: one (0.3%) sample was positive for E. histolytica, 44 (11.1%) samples were positive for G. lamblia, 122 (30.7%) samples were positive for D. fragilis, and three (0.8%) samples were positive for Cryptosporidium. TFT microscopy yielded 96 (24.2%) positive cases, including five double infections: one sample was positive for E. histolytica/Entamoeba dispar, 29 (7.3%) samples were positive for G. lamblia, 69 (17.4%) samples were positive for D. fragilis, and two (0.5%) samples were positive for Cryptosporidium hominis/Cryptosporidium parvum. Retrospective analysis of the clinical patient information of 2887 TFT sets showed that eosinophilia, elevated IgE levels, adoption and travelling to (sub)tropical areas are predisposing factors for infection with non-protozoal gastrointestinal parasites. The proposed diagnostic algorithm includes application of real-time PCR to all samples, with the addition of microscopy on an unpreserved faecal sample in cases of a predisposing factor, or a repeat request for parasitological examination. Application of real-time PCR improved the diagnostic yield by 18%. A single stool sample is sufficient for complete parasitological diagnosis when an algorithm based on clinical information is applied.
Alexander, Claire L; Niebel, Marc; Jones, Brian
Diagnostic testing in the United Kingdom for Cryptosporidium and Giardia species is routinely performed by microscopy. In this study, two hundred stool samples from human clinical cases were examined for the presence of these two parasites comparing microscopy with an antigen immunoassay, Quik Chek (Techlab, Inc.). The Quik Chek assay was shown to have a sensitivity and specificity for Cryptosporidium detection of 87.6% and 98.9% respectively and for Giardia detection, 93.3% and 99.4% respectively. The high correlation with microscopy data provides evidence to support implementation of this rapid test within diagnostic microbiology laboratories.
Lai, Tzung-Huei; Parraga, Maria E; Alvarez, Elizabeth; Rikihisa, Yasuko
Anaplasma platys is an uncultivable tick-borne obligatory intracellular bacterium, which is known to infect platelets of dogs. A. platys causes infectious canine cyclic thrombocytopenia in subtropical and tropical regions throughout the world. Several cases of human infection with A. platys infection have also been reported. However, seroprevalence of A. platys exposure and infection has not been determined in most of the regions, in part, due to lack of a simple and reliable assay method. Furthermore, A. platys antigens recognized by dogs are unknown. We previously sequenced gene encoding A. platys major outer membrane proteins P44 and Omp-1X. In the present study, we obtained purified recombinant A. platys P44 and Omp-1X proteins, and using them as antigens in immunoblotting examined seroreactivity in dogs. Of 34 specimens from Venezuela where A. platys infection was previously reported, 25 specimens (73.5%) reacted to rAplP44 and/or rAplOMP-1X. Neither Anaplasma phagocytophilum-seropositive (N = 10) nor A. phagocytophilum-seronegative canine specimens (N = 10) from the geographic regions where A. platys infection has never been reported, reacted rAplP44 or rAplOMP-1X. The result indicates a high A. platys seroprevalence rate in tested dogs from Venezuela and suggests that the immunoblot analysis based on recombinant A. platys major outer membrane proteins can provide a simple and defined tool to enlighten the prevalence of A. platys infection.
Dawson, George J
The potential uses of serological tests that detect HCV core antigens in biological fluids are highlighted. The most common serological tests utilized to detect exposure to HCV rely on the detection of antibodies to HCV. However, these tests cannot distinguish between individuals who have resolved their infection and those who remain actively infected with HCV. By contrast, the HCV core antigen test detects circulating HCV core antigen and identifies individuals who are actively infected with HCV. There is increasing interest in using the HCV core antigen test as a reflex test for seropositive individuals to identify individuals who are actively infected with HCV. In addition, the HCV core antigen test can be utilized to detect the early phase of HCV infection prior to the development of antibodies, both in the blood bank setting and in the diagnostic laboratory. Lastly, quantitative versions of the HCV core antigen test can be used to monitor the effectiveness of antiviral therapy.
Gomez, B L; Figueroa, J I; Hamilton, A J; Ortiz, B L; Robledo, M A; Restrepo, A; Hay, R J
Histoplasmosis is an important systemic fungal infection, particularly among immunocompromised individuals living or travelling in areas of endemicity, who, without antifungal therapy, may develop a progressive disseminated fatal infection. For such patients, the detection of antibody responses by immunodiffusion or complement fixation test is of limited use. In contrast, the detection of Histoplasma capsulatum circulating antigens may provide a more practical approach to the rapid diagnosis of the disease. Accordingly, an inhibition enzyme-linked immunosorbent assay (ELISA) for the detection of a 69- to 70-kDa H. capsulatum-specific determinant and incorporating a species-specific murine monoclonal antibody was developed. With sera from patients with different forms of the disease (n = 35), the overall sensitivity of the test was found to be 71.4%, while the specificity was found to be 98% with normal human sera from areas of endemicity (n = 44) and 85.4% with sera from patients with other chronic fungal or bacterial infections (n = 48). This novel, highly specific ELISA provides a significant addition to the existing diagnostic tests for the detection of histoplasmosis. PMID:9316918
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... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false The stained-antigen, rapid, whole-blood test. 3 147.3 Section 147.3 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... Blood Testing Procedures § 147.3 The stained-antigen, rapid, whole-blood test. 3 3 The...
... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false The stained-antigen, rapid, whole-blood test. 3 147.3 Section 147.3 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... Blood Testing Procedures § 147.3 The stained-antigen, rapid, whole-blood test. 3 3 The...
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Tumor-associated antigen immunological test system. 866.6010 Section 866.6010 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... immunological Test Systems § 866.6010 Tumor-associated antigen immunological test system. (a) Identification....
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Tumor-associated antigen immunological test system. 866.6010 Section 866.6010 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... immunological Test Systems § 866.6010 Tumor-associated antigen immunological test system. (a) Identification....
Kronenberg, Mitchell; Sullivan, Barbara A
How do CD1 molecules load lipid antigens? In this issue of Immunity, Relloso et al. (2008) uncover how lysosomal pH targets amino acids in CD1b, causing it to open and attain a conformation more receptive to lipid antigens.
Nordström, Tobias; Adolfsson, Jan; Grönberg, Henrik; Eklund, Martin
Despite limited scientific support, a repeat prostate-specific antigen (PSA) test before prostate biopsy decisions is common. We analyzed biopsy outcomes in 1686 men from the STHLM3 study with PSA 3-10 ng/mL and two PSA tests taken within eight weeks and before prostate biopsy using percentages and multinomial logistic regression. We found that omitting prostate biopsy for men with PSA values decreasing to PSAs of 3 ng/mL or less would save 16.8% of biopsy procedures, while missing 5.4% of the cancers with Gleason scores (GSs) of 7 or higher. The proportion of cancers with GSs of 6 or lower was independent of the first PSA value, as well as of PSA change. Also, the risk of tumors with GSs of 7 or higher decreased with both decreasing and increasing PSA levels: It was 18.6% (95% confidence interval [CI] = 16.3% to 20.9%) for men with PSA changes of less than 20%, 12.1% (95% CI = 8.0% to 16.2%) for men with PSA levels increasing at least 20%, and 6.6% (95% CI = 3.8% to 9.3%) for men with PSA levels decreasing at least 20%.
Lamberton, Poppy H. L.; Kabatereine, Narcis B.; Oguttu, David W.; Fenwick, Alan; Webster, Joanne P.
Background Two Kato-Katz thick smears (Kato-Katzs) from a single stool are currently recommended for diagnosing Schistosoma mansoni infections to map areas for intervention. This ‘gold standard’ has low sensitivity at low infection intensities. The urine point-of-care circulating cathodic antigen test (POC-CCA) is potentially more sensitive but how accurately they detect S. mansoni after repeated praziquantel treatments, their suitability for measuring drug efficacy and their correlation with egg counts remain to be fully understood. We compared the accuracies of one to six Kato-Katzs and one POC-CCA for the diagnosis of S. mansoni in primary-school children who have received zero to ten praziquantel treatments. We determined the impact each diagnostic approach may have on monitoring and evaluation (M&E) and drug-efficacy findings. Method/Principle Findings In a high S. mansoni endemic area of Uganda, three days of consecutive stool samples were collected from primary school-aged children (six - 12 years) at five time-points in year one: baseline, one-week-post-, four-weeks-post-, six-months-post-, and six-months-one-week-post-praziquantel and three time-points in years two and three: pre-, one-week-post- and four-weeks-post-praziquantel-treatment/retreatment (n = 1065). Two Kato-Katzs were performed on each stool. In parallel, one urine sample was collected and a single POC-CCA evaluated per child at each time-point in year one (n = 367). At baseline, diagnosis by two Kato-Katzs (sensitivity = 98.6%) or one POC-CCA (sensitivity = 91.7%, specificity = 75.0%) accurately predicted S. mansoni infections. However, one year later, a minimum of three Kato-Katzs, and two years later, five Kato-Katzs were required for accurate diagnosis (sensitivity >90%) and drug-efficacy evaluation. The POC-CCA was as sensitive as six Kato-Katzs four-weeks-post and six-months-post-treatment, if trace readings were classified as positive. Conclusions
... 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....
... 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....
... 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....
... 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....
... 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....
Community Laboratory Testing for Cryptosporidium: Multicenter Study Retesting Public Health Surveillance Stool Samples Positive for Cryptosporidium by Rapid Cartridge Assay with Direct Fluorescent Antibody Testing
Roellig, Dawn M.; Yoder, Jonathan S.; Madison-Antenucci, Susan; Robinson, Trisha J.; Van, Tam T.; Collier, Sarah A.; Boxrud, Dave; Monson, Timothy; Bates, Leigh Ann; Blackstock, Anna J.; Shea, Shari; Larson, Kirsten; Xiao, Lihua; Beach, Michael
Cryptosporidium is a common cause of sporadic diarrheal disease and outbreaks in the United States. Increasingly, immunochromatography-based rapid cartridge assays (RCAs) are providing community laboratories with a quick cryptosporidiosis diagnostic method. In the current study, the Centers for Disease Control and Prevention (CDC), the Association of Public Health Laboratories (APHL), and four state health departments evaluated RCA-positive samples obtained during routine Cryptosporidium testing. All samples underwent “head to head” re-testing using both RCA and direct fluorescence assay (DFA). Community level results from three sites indicated that 54.4% (166/305) of Meridian ImmunoCard STAT! positives and 87.0% (67/77) of Remel Xpect positives were confirmed by DFA. When samples were retested by RCA at state laboratories and compared with DFA, 83.3% (155/186) of Meridian ImmunoCard STAT! positives and 95.2% (60/63) of Remel Xpect positives were confirmed. The percentage of confirmed community results varied by site: Minnesota, 39.0%; New York, 63.9%; and Wisconsin, 72.1%. The percentage of confirmed community results decreased with patient age; 12.5% of community positive tests could be confirmed by DFA for patients 60 years of age or older. The percentage of confirmed results did not differ significantly by sex, storage temperature, time between sample collection and testing, or season. Findings from this study demonstrate a lower confirmation rate of community RCA positives when compared to RCA positives identified at state laboratories. Elucidating the causes of decreased test performance in order to improve overall community laboratory performance of these tests is critical for understanding the epidemiology of cryptosporidiosis in the United States (US). PMID:28085927
Community Laboratory Testing for Cryptosporidium: Multicenter Study Retesting Public Health Surveillance Stool Samples Positive for Cryptosporidium by Rapid Cartridge Assay with Direct Fluorescent Antibody Testing.
Roellig, Dawn M; Yoder, Jonathan S; Madison-Antenucci, Susan; Robinson, Trisha J; Van, Tam T; Collier, Sarah A; Boxrud, Dave; Monson, Timothy; Bates, Leigh Ann; Blackstock, Anna J; Shea, Shari; Larson, Kirsten; Xiao, Lihua; Beach, Michael
Cryptosporidium is a common cause of sporadic diarrheal disease and outbreaks in the United States. Increasingly, immunochromatography-based rapid cartridge assays (RCAs) are providing community laboratories with a quick cryptosporidiosis diagnostic method. In the current study, the Centers for Disease Control and Prevention (CDC), the Association of Public Health Laboratories (APHL), and four state health departments evaluated RCA-positive samples obtained during routine Cryptosporidium testing. All samples underwent "head to head" re-testing using both RCA and direct fluorescence assay (DFA). Community level results from three sites indicated that 54.4% (166/305) of Meridian ImmunoCard STAT! positives and 87.0% (67/77) of Remel Xpect positives were confirmed by DFA. When samples were retested by RCA at state laboratories and compared with DFA, 83.3% (155/186) of Meridian ImmunoCard STAT! positives and 95.2% (60/63) of Remel Xpect positives were confirmed. The percentage of confirmed community results varied by site: Minnesota, 39.0%; New York, 63.9%; and Wisconsin, 72.1%. The percentage of confirmed community results decreased with patient age; 12.5% of community positive tests could be confirmed by DFA for patients 60 years of age or older. The percentage of confirmed results did not differ significantly by sex, storage temperature, time between sample collection and testing, or season. Findings from this study demonstrate a lower confirmation rate of community RCA positives when compared to RCA positives identified at state laboratories. Elucidating the causes of decreased test performance in order to improve overall community laboratory performance of these tests is critical for understanding the epidemiology of cryptosporidiosis in the United States (US).
Coulibaly, Jean T.; Knopp, Stefanie; N'Guessan, Nicaise A.; Silué, Kigbafori D.; Fürst, Thomas; Lohourignon, Laurent K.; Brou, Jean K.; N'Gbesso, Yve K.; Vounatsou, Penelope; N'Goran, Eliézer K.; Utzinger, Jürg
Background Promising results have been reported for a urine circulating cathodic antigen (CCA) test for the diagnosis of Schistosoma mansoni. We assessed the accuracy of a commercially available CCA cassette test (designated CCA-A) and an experimental formulation (CCA-B) for S. mansoni diagnosis. Methodology We conducted a cross-sectional survey in three settings of Côte d'Ivoire: settings A and B are endemic for S. mansoni, whereas S. haematobium co-exists in setting C. Overall, 446 children, aged 8–12 years, submitted multiple stool and urine samples. For S. mansoni diagnosis, stool samples were examined with triplicate Kato-Katz, whereas urine samples were tested with CCA-A. The first stool and urine samples were additionally subjected to an ether-concentration technique and CCA-B, respectively. Urine samples were examined for S. haematobium using a filtration method, and for microhematuria using Hemastix dipsticks. Principal Findings Considering nine Kato-Katz as diagnostic ‘gold’ standard, the prevalence of S. mansoni in setting A, B and C was 32.9%, 53.1% and 91.8%, respectively. The sensitivity of triplicate Kato-Katz from the first stool and a single CCA-A test was 47.9% and 56.3% (setting A), 73.9% and 69.6% (setting B), and 94.2% and 89.6% (setting C). The respective sensitivity of a single CCA-B was 10.4%, 29.9% and 75.0%. The ether-concentration technique showed a low sensitivity for S. mansoni diagnosis (8.3–41.0%). The specificity of CCA-A was moderate (76.9–84.2%); CCA-B was high (96.7–100%). The likelihood of a CCA-A color reaction increased with higher S. mansoni fecal egg counts (odds ratio: 1.07, p<0.001). A concurrent S. haematobium infection or the presence of microhematuria did not influence the CCA-A test results for S. mansoni diagnosis. Conclusion/Significance CCA-A showed similar sensitivity than triplicate Kato-Katz for S. mansoni diagnosis with no cross-reactivity to S. haematobium and microhematuria. The low sensitivity of
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
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
Siegel, D; Cohen, P T; Neighbor, M; Larkin, H; Newman, M; Yajko, D; Hadley, K
We prospectively evaluate the value of fecal blood and fecal leukocytes in predicting whether acute diarrhea in adults is associated with a stool culture positive for a bacterial pathogen. One hundred thirteen patients, aged 19 to 50 years, seen in a two-year period in an urban adult outpatient setting underwent stool culture for the presenting symptom of diarrhea. Heterosexual men represented 48% of the cohort, women represented 17%, and homosexual men represented 35%. Overall, 53 (47%) of the patients had positive stool cultures for enteric pathogens. Campylobacter jejuni was the most common organism in the entire cohort, but Shigella species were most common in homosexual men. The best predictive variables for a stool culture positive for a bacterial pathogen were the presence of both fecal leukocytes and fecal blood in the stool, compared with only one or neither. When both were present, the sensitivity was 81%, the specificity 74%, and the predictive values of a positive and negative test were 81% and 83%, respectively; the likelihood ratio was 4.87. When homosexual men and the rest of the cohort were analyzed separately, the combination of fecal leukocytes and fecal blood remained the best method of predicting a positive stool culture in both. Examination of stool for fecal leukocytes and fecal blood is a rapid, reliable, and inexpensive way to differentiate between bacterial and other causes of acute diarrhea in the adult acute care setting.
... Everyone has friendly bacteria in their intestines. Normal value ranges may vary slightly among different laboratories. Talk to your health care provider about the meaning of your specific test results.
Finkelstein, Richard A.; Pongpairojana, Smarn
The antigenicity of a large number of cholera vibrio strains was compared, in groups of rabbits, by evaluating the serological responses to single limited doses of vaccines prepared from the strains. On the basis of these tests, it was possible to construct 2 quadrivalent (El Tor and classical, Inaba and Ogawa) vaccines which differed significantly in antigenicity for rabbits but which were indistinguishable in the “standard” mouse-protection test. The advisability of using a test of antigenicity for selection of strains and laboratory evaluation of vaccines is considered. Application of the proposed antigenicity test would depend on further comparisons of human response to vaccines which differ in antigenicity for the rabbit. ImagesFIG. 4 PMID:5303406
Trabelsi, Sonia; Aouinet, Amira; Khaled, Samira
Intestinal parasites are a public health problem in the world especially in tropical and subtropical countries. Despite the improvement in living standards and healthy conditions, these parasitoses remain relatively frequent in Tunisia. Stool specimen examination keeps the fundamental test for screening and diagnosis. It is to directly search the parasite. Respect for the right procedure of collection of stool is an essential step for the reliability and proper interpretation of results of this examination.
El-Ghareeb, Azza S; Abd El Motaleb, Ghada S; Waked, Nevien Maher; Osman Hany Kamel, Nancy; Aly, Nagwa Shaban
Urinary schistosomiasis caused by Schistosoma haematobium constitutes a major public health problem in many tropical and sub-tropical countries. This study was conducted to evaluate circulating cathodic antigen cassette test and haematuria strip test for detection of S. haematobium in urine samples and to evaluate their screening performance among the study population. Microscopy was used as a gold standard. A total of 600 urine samples were examined by microscopy for detection of S. haematobium eggs, screened for microhaematuria using Self-Stik reagent strips and screened for circulating cathodic antigen (CCA) using the urine-CCA cassette test. The specificity of CCA, microhaematuria and macrohaematuria was 96.4, 40.6 and 31.2 % respectively while the sensitivity was 88.2, 99.3 and 100 % respectively which was statistically significant (P < 0.001). These findings suggest that using of urine-CCA cassette test in diagnosis of urinary schistosomiasis is highly specific (96.4 %) compared with the highly sensitive haematuria strip test (100 %). The degree of agreement between microscopic examination and CCA detection was 99.3 % with highly statistically significant difference (P < 0.001). The combination of two techniques could potentially use for screening and mapping of S. haematobium infection.
Kessler, Bernhard; Bally, Frank; Hewer, Ekkehard; Sendi, Parham
Cryptococcus spp. commonly causes infection in immunocompromised hosts. Clinical presentation of cryptococcal meningoencephalitis (CM) is variable, but headache, fever and a high intracranial pressure should suggest the diagnosis. The cryptococcal antigen test is a specific and sensitive rapid test that can be performed on blood or cerebrospinal fluid. We report a case of CM in a patient with previously undetected lymphocytopenia. Because cryptococcal antigen test results were negative, diagnosis and treatment were delayed.
Lucero, Nidia E.; Bolpe, Jorge E.
Brucellosis in Argentina is currently investigated in bank donor blood by the standard plate agglutination test (PAT). This study evaluated the buffered plate antigen test (BPA), now used to screen for bovine brucellosis, as a screen for human disease. Of 57 sera from patients with culture-confirmed brucellosis, 100% were detected with the BPA. Of 142 sera positive by rose bengal (RB) and complement fixation (CF), from patients with clinical evidence of brucellosis, the BPA detected 100%. Of 307 sera from a nonsymptomatic population that were RB and CF negative, the BPA detected 99.67% of the negative sera. The data indicate that the BPA is satisfactory compared to the other agglutination tests employed. It is an inexpensive and practical screening test and reduces the nonspecific reactions detected by the PAT. PMID:9574720
Background Determining the variation of circulating cathodic antigen (CCA) in urine and egg counts variation in stool between days in Schistosoma mansoni (S. mansoni) infected individuals is vital to decide whether or not to rely on a single-sample test for diagnosis of Schistosomiasis. In this study, the magnitude of day-to-day variation in urine-CCA test scores and in faecal egg counts was evaluated in school children in Ethiopia. Methods A total of 620 school children (age 8 to 12 years) were examined for S. mansoni infection using double Kato-Katz and single urine-CCA cassette methods (batch 32727) on three consecutive days. Results The prevalence of S. mansoni infection was 81.1% based on triple urine-CCA-cassette test and 53.1% based on six Kato-Katz thick smears. Among the study participants, 26.3% showed fluctuation in urine CCA and 32.4% showed fluctuation in egg output. Mean egg count as well as number of cases in each class of intensity and intensity of cassette band color varied over the three days of examination. Over 85% of the children that showed day-to-day variations in status of S. mansoni infection from negative to positive or vice versa by the Kato-Katz and the CCA methods had light intensity of infection. The fluctuation in both the CCA test scores and faecal egg count was not associated with age and sex. Conclusions The current study showed day-to-day variation in CCA and Kato-Katz test results of children infected with S. mansoni. This indicates the necessity of more than one urine or stool samples to be collected on different days for more reliable diagnosis of S. mansoni infection in low endemic areas. PMID:24742192
Newman, R D; Jaeger, K L; Wuhib, T; Lima, A A; Guerrant, R L; Sears, C L
The diagnosis of the small (4- to 6-microns) Cryptosporidium oocysts is labor intensive and relies on stool concentration, with subsequent staining and microscopy. The primary purpose of this study was to evaluate the clinical utility of an antigen capture enzyme-linked immunosorbent assay (ELISA) (LMD Laboratories, Carlsbad, Calif.) in detecting Cryptosporidium oocysts in human stools. A total of 591 specimens (76 diarrheal, 515 control) obtained from 213 inhabitants of an urban slum in northeastern Brazil were examined by both ELISA and conventional microscopic examination (CME) of formalin-ethyl acetate-concentrated stool samples stained with modified acid-fast and auramine stains. Forty-eight diarrheal stools (63.2%) were positive for Cryptosporidium oocysts by CME, with 40 of these positive by ELISA. Thirty-five control stools (6.8%) had Cryptosporidium oocysts detected by CME, with 15 of these also positive by ELISA. All of the 480 nondiarrheal stools and all but one of the diarrheal stools negative by CME were negative by ELISA. The test had an overall sensitivity of 66.3% and a specificity of 99.8% (positive predictive value, 98.2%; negative predictive value, 94.8%). In the evaluation of human diarrheal stool samples, the test sensitivity increased to 83.3%, with a specificity of 96.4%, and, in analysis of samples from individual patients with diarrhea, the sensitivity was 87.9%, with a specificity of 100%. These results indicate that this stool ELISA is sensitive and specific for the detection of Cryptosporidium oocysts in human diarrheal stool specimens but has limited use in epidemiologic studies for the diagnosis of asymptomatic Cryptosporidium infection. PMID:8370732
Stavri, Henriette; Bucurenci, Nadia; Ulea, Irina; Costache, Adriana; Popa, Loredana; Popa, Mircea Ioan
Background & objectives: Purified protein derivative (PPD) is currently the only available skin test reagent used worldwide for the diagnosis of tuberculosis (TB). The aim of this study was to develop a Mycobacterium tuberculosis specific skin test reagent, without false positive results due to Bacillus Calmette-Guerin (BCG) vaccination using recombinant antigens. Methods: Proteins in PPD IC-65 were analyzed by tandem mass spectrometry and compared to proteins in M. tuberculosis culture filtrate; 54 proteins were found in common. Top candidates MPT64, ESAT 6, and CFP 10 were overexpressed in Escherichia coli expression strains and purified as recombinant proteins. To formulate optimal immunodiagnostic PPD cocktails, the antigens were evaluated by skin testing guinea pigs sensitized with M. tuberculosis H37Rv and BCG. Results: For single antigens and a cocktail mixture of these antigens, best results were obtained using 3 μg/0.1 ml, equivalent to 105 TU (tuberculin units). Each animal was simultaneously tested with PPD IC-65, 2 TU/0.1 ml, as reference. Reactivity of the multi-antigen cocktail was greater than that of any single antigen. The skin test results were between 34.3 and 76.6 per cent the level of reactivity compared to that of the reference when single antigens were tested and 124 per cent the level of reactivity compared to the reference for the multi-antigen cocktail. Interpretation & conclusions: Our results showed that this specific cocktail could represent a potential candidate for a new skin diagnostic test for TB. PMID:23287127
Parlane, Natalie A; Chen, Shuxiong; Jones, Gareth J; Vordermeier, H Martin; Wedlock, D Neil; Rehm, Bernd H A; Buddle, Bryce M
The tuberculin skin test is the primary screening test for the diagnosis of bovine tuberculosis (TB), and use of this test has been very valuable in the control of this disease in many countries. However, the test lacks specificity when cattle have been exposed to environmental mycobacteria or vaccinated with Mycobacterium bovis bacille Calmette-Guérin (BCG). Recent studies showed that the use of three or four recombinant mycobacterial proteins, including 6-kDa early secretory antigenic target (ESAT6), 10-kDa culture filtrate protein (CFP10), Rv3615c, and Rv3020c, or a peptide cocktail derived from those proteins, in the skin test greatly enhanced test specificity, with minimal loss of test sensitivity. The proteins are present in members of the pathogenic Mycobacterium tuberculosis complex but are absent in or not expressed by the majority of environmental mycobacteria and the BCG vaccine strain. To produce a low-cost skin test reagent, the proteins were displayed at high density on polyester beads through translational fusion to a polyhydroxyalkanoate synthase that mediates the formation of antigen-displaying inclusions in recombinant Escherichia coli. Display of the proteins on the polyester beads greatly increased their immunogenicity, allowing for the use of very low concentrations of proteins (0.1 to 3 μg of mycobacterial protein/inoculum) in the skin test. Polyester beads simultaneously displaying all four proteins were produced in a single fermentation process. The polyester beads displaying three or four mycobacterial proteins were shown to have high sensitivity for detection of M. bovis-infected cattle and induced minimal responses in animals exposed to environmental mycobacteria or vaccinated with BCG.
Background Hantaviruses are causative agents of hemorrhagic fever with renal syndrome (HFRS) and nephropathia epidemica (NE) in the Old World and hantavirus pulmonary syndrome (HPS) in the New World. There is a need for time-saving diagnostic methods. In the present study, recombinant N antigens were used as antigens in an immunochromatography strip (ICG) test to detect specific IgG antibodies. Methods The N-terminal 103 amino acids (aa) of Hantaan virus (HTNV), Puumala virus (PUUV) and Andes virus (ANDV) nucleocapsid (N) protein were expressed in E. coli as representative antigens of three groups (HFRS, NE and HPS-causing viruses) of hantavirus. Five different types of ICG test strips, one antigen line on one strip for each of the three selected hantaviruses (HTNV, PUUV and ANDV), three antigen lines on one strip and a mixed antigen line on one strip, were developed and sensitivities were compared. Results A total of 87 convalescent-phase patient sera, including sera from 35 HFRS patients, 36 NE patients and 16 HPS patients, and 25 sera from healthy seronegative people as negative controls were used to evaluate the ICG test. Sensitivities of the three-line strip and mixed-line strip were similar to those of the single antigen strip (97.2 to 100%). On the other hand, all of the ICG test strips showed high specificities to healthy donors. Conclusion These results indicated that the ICG test with the three representative antigens is an effective serodiagnostic tool for screening and typing of hantavirus infection in humans. PMID:24885901
Fleece, Molly E.; Heptinstall, Jack; Khan, Shaila S.; Kabir, Mamum; Herbein, Joel; Haque, Rashidul; Petri, William A.
A new rapid lateral flow fecal antigen detection test for Cryptosporidium was evaluated using diarrheal stool samples from a cohort of children in Bangladesh. The test had a sensitivity of 100% and a specificity of 94% when compared with enzyme-linked immunosorbent assay antigen detection. PMID:27573629
Schneider, L. G.; Dietzschold, B.; Dierks, R. E.; Matthaeus, W.; Enzmann, P.-J.; Strohmaier, K.
Cell-associated ribonucleoprotein (RNP) was isolated from BHK-21 cells infected with several strains of rabies and rabies-related viruses. The RNP-antigen from rabies and related viruses induced the formation of complement-fixing, precipitating, and immunofluorescent antibodies, and proved to be the group-specific antigen common to all rabies viruses. Antigens of the envelope which induce virus-neutralizing antibodies are apparently determinative for the serotype of a virus as evidenced by two-way neutralization tests. A combination of these methods seems to be a useful approach to the serological grouping and typing of rhabdoviruses. Images PMID:4196634
...-blood test. 3 147.3 Section 147.3 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... Blood Testing Procedures § 147.3 The stained-antigen, rapid, whole-blood test. 3 3 The procedure... Secretary of Agriculture. (b) A loop for measuring the correct quantity of blood can usually be...
Ganova, L A; Kovtoniuk, G V; Korshun, L N; Kiseleva, E K; Tereshchenko, M I; Vudmaska, M I; Moĭsa, L N; Shevchuk, V A; Spivak, N Ia
The lysate and recombinant antigens of various production included informula of ELISA-test-systems were analyzed. The ELISA-test-systems are used for detection of IgG to Herpes simplex virus type I and II. For testing the panel of serums PTH 201 (BBI Inc.) were used. The samples of this panel contain antibodies to Herpes simplex virus type I and II in mixed titers. The 69 serums of donors were used too (17 samples had IgG to Herpes simplex virus type I, 23 samples to Herpes simplex virus type II and 29 samples had no antibodies to Herpes simplex virus). The diagnostic capacity of mixture of recombinant antigens gG1 Herpes simplex virus type I and gG2 Herpes simplex virus type II (The research-and-production complex "DiaprofMed") was comparable with mixture of lysate antigen Herpes simplex virus type I and II (Membrane) EIE Antigen ("Virion Ltd."). In the test-systems for differentiation of IgG to Herpes simplex virus type I the recombinant antigen gG1 Herpes simplex virus type I proved to be comparable with commercial analogue Herpes simplex virus-1 gG1M ("Viral Therapeutics Inc."'). At the same time, capacity to detect IgG to Herpes simplex virus type II in recombinant protein gG2 Herpes simplex virus type II is significantly higher than in its analogue Herpes simplex virus-2 gG2c ("Viral Therapeutics Inc.").
Qualification of Cell Substrates and Other Biological Materials Used in the Production of Viral Vaccines for Infectious Disease Indications"(2010). The tests...product formulation was a phosphate buffer system as formulated below: 12.5mM Na2HPO4 12.5mM NaH2PO4 8.5% NaCl 0.4% Phenol 1.0% Glycerol 0.01...prior infection with the parasite. The test is commonly used to screen candidates in Leishmania vaccine trials. The skin test also has been used as a
West, Devin M; McCauley, Lindsay M; Sorensen, Jeffrey S; Jephson, Al R; Dean, Nathan C
The pneumocococcal urine antigen test increases specific microbiological diagnosis over conventional culture methods in pneumonia patients. Data are limited regarding its yield and effect on antibiotic prescribing among patients with community-onset pneumonia in clinical practice. We performed a secondary analysis of 2837 emergency department patients admitted to seven Utah hospitals over 2 years with international diagnostic codes version 9 codes and radiographic evidence of pneumonia. Mean age was 64.2 years, 47.2% were male and all-cause 30-day mortality was 9.6%. Urinary antigen testing was performed in 1110 (39%) patients yielding 134 (12%) positives. Intensive care unit patients were more likely to undergo testing, and have a positive result (15% versus 8.8% for ward patients; p<0.01). Patients with risk factors for healthcare-associated pneumonia had fewer urinary antigen tests performed, but 8.4% were positive. Physicians changed to targeted antibiotic therapy in 20 (15%) patients, de-escalated antibiotic therapy in 76 patients (57%). In 38 (28%) patients, antibiotics were not changed. Only one patient changed to targeted therapy suffered clinical relapse. Length of stay and mortality were lower in patients receiving targeted therapy. Pneumococcal urinary antigen testing is an inexpensive, noninvasive test that favourably influenced antibiotic prescribing in a "real world", multi-hospital observational study.
West, Devin M.; McCauley, Lindsay M.; Sorensen, Jeffrey S.; Jephson, Al R.
The pneumocococcal urine antigen test increases specific microbiological diagnosis over conventional culture methods in pneumonia patients. Data are limited regarding its yield and effect on antibiotic prescribing among patients with community-onset pneumonia in clinical practice. We performed a secondary analysis of 2837 emergency department patients admitted to seven Utah hospitals over 2 years with international diagnostic codes version 9 codes and radiographic evidence of pneumonia. Mean age was 64.2 years, 47.2% were male and all-cause 30-day mortality was 9.6%. Urinary antigen testing was performed in 1110 (39%) patients yielding 134 (12%) positives. Intensive care unit patients were more likely to undergo testing, and have a positive result (15% versus 8.8% for ward patients; p<0.01). Patients with risk factors for healthcare-associated pneumonia had fewer urinary antigen tests performed, but 8.4% were positive. Physicians changed to targeted antibiotic therapy in 20 (15%) patients, de-escalated antibiotic therapy in 76 patients (57%). In 38 (28%) patients, antibiotics were not changed. Only one patient changed to targeted therapy suffered clinical relapse. Length of stay and mortality were lower in patients receiving targeted therapy. Pneumococcal urinary antigen testing is an inexpensive, noninvasive test that favourably influenced antibiotic prescribing in a “real world”, multi-hospital observational study. PMID:28053969
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...
Biéler, Sylvain; Waltenberger, Harald; Barrett, Michael P.; McCulloch, Richard; Mottram, Jeremy C.; Carrington, Mark; Schwaeble, Wilhelm; McKerrow, James; Phillips, Margaret A.; Michels, Paul A.; Büscher, Philippe; Sanchez, Jean-Charles; Bishop, Richard; Robinson, Derrick R.; Bangs, James; Ferguson, Michael; Nerima, Barbara; Albertini, Audrey; Michel, Gerd; Radwandska, Magdalena; Ndung’u, Joseph Mathu
Background Control and elimination of human African trypanosomiasis (HAT) can be accelerated through the use of diagnostic tests that are more accurate and easier to deploy. The goal of this work was to evaluate the immuno-reactivity of antigens and identify candidates to be considered for development of a simple serological test for the detection of Trypanosoma brucei gambiense or T. b. rhodesiense infections, ideally both. Methodology/Principal Findings The reactivity of 35 antigens was independently evaluated by slot blot and ELISA against sera from both T. b. gambiense and T. b. rhodesiense infected patients and controls. The antigens that were most reactive by both tests to T. b. gambiense sera were the membrane proteins VSG LiTat 1.3, VSG LiTat 1.5 and ISG64. Reactivity to T. b. rhodesiense sera was highest with VSG LiTat 1.3, VSG LiTat 1.5 and SRA, although much lower than with T. b. gambiense samples. The reactivity of all possible combinations of antigens was also calculated. When the slot blot results of 2 antigens were paired, a VSG LiTat 1.3- ISG75 combination performed best on T. b. gambiense sera, while a VSG LiTat 1.3-VSG LiTat 1.5 combination was the most reactive using ELISA. A combination of SRA and either VSG LiTat 1.3 or VSG LiTat 1.5 had the highest reactivity on T. b. rhodesiense sera according to slot blot, while in ELISA, pairing SRA with either GM6 or VSG LiTat 1.3 yielded the best results. Conclusions This study identified antigens that were highly reactive to T. b. gambiense sera, which could be considered for developing a serological test for gambiense HAT, either individually or in combination. Antigens with potential for inclusion in a test for T. b. rhodesiense HAT were also identified, but because their reactivity was comparatively lower, a search for additional antigens would be required before developing a test for this form of the disease. PMID:27936225
”Australia” antigen has been shown to be closely associated with serum hepatitis. The presence of the antigen and its corresponding antiserum can be detected in human beings (and in certain primates) by a number of laboratory tests. This is of great potential importance to blood transfusion and similar services because detection and exclusion of blood donors carrying the antigen might significantly reduce the risk of hepatitis from transfusions and other procedures. In this paper the present state of knowledge of ”Australia” or ”hepatitis-associated” antigen is reviewed. The currently employed tests are described in detail and their use, interpretation and limitations are discussed. Though it appears from early studies that the application of routine screening tests to blood donors would only reduce the risk to recipients by less than 25%, the more sensitive tests becoming available may increase this percentage and it is recommended that where competent laboratory services are available steps should be taken to set up a scheme for testing donors—provided that the current limitations of such a scheme are clearly recognized. ImagesFIG. 2FIG. 3FIG. 1FIG. 6FIG. 7FIG. 8 PMID:4991606
Pourakbari, Babak; Ghazi, Mona; Mahmoudi, Shima; Mamishi, Setareh; Azhdarkosh, Hossein; Najafi, Mehri; Kazemi, Bahram; Salavati, Ali; Mirsalehian, Akbar
Although several invasive and noninvasive tests have been developed for the diagnosis of Helicobacter pylori infection, all of the tests have their limitations. We conducted a study to investigate and compare the suitability of rapid urease test (RUT), serology, histopathology and stool antigen tests with polymerase chain reaction (PCR) for detection of H. pylori, and correlate the diagnostic methods with PCR. Eighty nine patients (61 adults, 28 children) referred to the Firoozgar Hospital and Children Medical Center Hospital for diagnostic upper gastrointestinal endoscopy entered to the study and noninvasive tests such as immunoassay for serological antibodies against H. pylori and detection of its antigen in feces were measured. The biopsies were utilized for histological examination, RUT and PCR. The H. pylori statuses were evaluated by the positivity of ureC PCR in biopsy specimens and 53 subjects had H. pylori positive result. Histopathology showed high overall performance in adults and children with sensitivity and specificity 100% and 90%, respectively. Sensitivity, specificity, and accuracy for stool antigen test were 87.8%, 75% and 82%, respectively. Correlation of RUT, serology (IgG), histopathology and stool antigen tests with PCR were 0.82, 0.32, 0.91 and 0.63, respectively. In conclusion, the RUT and histopathology are as accurate as the PCR of biopsy and stool antigen test can consider as appropriate noninvasive test for detection of H. pylori infection.
Objective: Vaccination decreases morbidity and mortality. Vaccine efficacy may be lower in less-developed countries due to environmental enteropathy. This study determined if relative abundance of stool bacteria predicted infant vaccine responses. Methods: The stool microbiome of 48 breastfed Ba...
Merson, M H; Yolken, R H; Sack, R B; Froehlich, J L; Greenberg, H B; Huq, I; Black, R W
We determined whether enterotoxigenic Escherichia coli diarrhea could be diagnosed by direct examination of stools for heat-labile (LT) and heat-stable (ST) enterotoxins. The Y-1 adrenal cell and an enzyme-linked immunosorbent assay (ELISA) detected LT in 85 and 93%, respectively, of stool specimens obtained from adults with acute diarrhea from whom an LT- and ST-producing organism had been isolated. Furthermore, the ELISA assay detected LT in 8 of 35 stool specimens from which no LT-producing E. coli had been isolated. The infant mouse assay was utilized to detect ST in these stool specimens and was found to be an insensitive method, showing positive results in only 36% of the specimens from which an ST-producing organism was isolated. Further studies are warranted to determine the diagnostic value of direct detection of LT in stools, especially by the ELISA method. PMID:6995331
Wang, Huanrong; Yuan, Xueqian; Zhang, Lifeng
This paper aims to discuss the early diagnosis value of latex agglutination test in Cryptococcal meningitis. The cerebrospinal fluid (CSF) of 112 patients with definite Cryptococcal meningitis and 26 patients with tubercular meningitis and virus meningitis were collected, latex agglutination test is adopted to detect Cryptococcal capsular polysaccharide antigen. Then it was compared with fungal culture and direct microscopy method for evaluating the sensitivity and specificity of the diagnosis. The sensitivity of three methods including latex agglutination test, fungal culture and direct microscopy was 91.1%,69.6% and 73.2% respectively. The specificity of latex agglutination test was 96.0%, 100% and 100% respectively. That latex agglutination test to detect Cryptococcal capsular polysaccharide antigen could be taken as the early diagnostic method of Cryptococcus neoformans meningitis.
Tone, Kazuya; Umeda, Yoshiko; Makimura, Koichi
This article presents an examination of the cross-reactivity of pathogenic fungi with Cryptococcus neoformans in two commercial Cryptococcus antigen latex agglutination tests performed across 39 fungal strains. Some fungi were newly indicated as Cryptococcus cross-reactive, and the two kits showed differences in cross-reactive fungi.
Lu, Hongzhou; Zhou, Yingjie; Yin, Youkuan; Pan, Xiaozhang; Weng, Xinhua
For a total of 29 non-human immunodeficiency virus 1 cryptococcal meningitis cases, titer changes in the latex agglutination test before and after therapy were reviewed along with clinical manifestations, laboratory findings, and therapy regimens. The cryptococcal antigen titer decreased for every case after therapy and was correlated to fungal clearance as defined by fungus smear and/or culture. However, cryptococcal antigen can remain at low titers for long periods of time after therapy, even when fungus smears and/or cultures become negative.
Duthie, Malcolm S.; Ireton, Greg C.; Kanaujia, Ganga V.; Goto, Wakako; Liang, Hong; Bhatia, Ajay; Busceti, Jean Marie; Macdonald, Murdo; Neupane, Kapil Dev; Ranjit, Chaman; Sapkota, Bishwa Raj; Balagon, Marivic; Esfandiari, Javan; Carter, Darrick; Reed, Steven G.
Leprosy can be a devastating chronic infection that causes nerve function impairment and associated disfigurement. Despite the recent reduction in the number of registered worldwide leprosy cases as a result of the widespread use of multidrug therapy, the number of new cases detected each year remains relatively stable. The diagnosis of leprosy is currently based on the appearance of clinical signs and requires expert clinical, as well as labor-intensive and time-consuming laboratory or histological, evaluation. For the purpose of developing an effective, simple, rapid, and low-cost diagnostic alternative, we have analyzed the serologic antibody response to identify Mycobacterium leprae proteins that are recognized by leprosy patients. More than 100 recombinant antigens were analyzed in a protein array format to select those with discriminatory properties for leprosy diagnosis. As expected, multibacillary leprosy patients recognized more antigens with stronger antibody responses than paucibacillary leprosy patients. Our data indicate, however, that multibacillary patients can be distinguished from paucibacillary patients, and both of these groups can be segregated from endemic control groups. We went on to confirm the diagnostic properties of antigens ML0405 and ML2331 and the LID-1 fusion construct of these two proteins by enzyme-linked immunosorbent assay. We then demonstrated the performance of these antigens in rapid test formats with a goal of developing a point-of-care diagnostic test. A serological diagnostic test capable of identifying and allowing treatment of leprosy could reduce transmission, prevent functional disabilities and stigmatizing deformities, and facilitate leprosy eradication. PMID:18716007
Cheong, Seung Hyun; Choi, You Won; Myung, Ki Bum
Background Currently, cosmetic series (Chemotechnique Diagnostics, Sweden) is the most widely used cosmetic-related patch test in Korea. However, no studies have been conducted on how accurately it reflects the constituents of the cosmetics in Korea. Objective We surveyed the constituents of various cosmetics and compare with the cosmetic series, to investigate whether it is accurate in determining allergic contact dermatitis caused by cosmetics sold in Korea. Methods Cosmetics were classified into 11 categories and the survey was conducted on the constituents of 55 cosmetics, with 5 cosmetics in each category. The surveyed constituents were classified by chemical function and compared with the antigens of cosmetic series. Results 155 constituents were found in 55 cosmetics, and 74 (47.7%) of constituents were included as antigen. Among them, only 20 constituents (27.0%) were included in cosmetic series. A significant number of constituents, such as fragrance, vehicle and surfactant were not included. Only 41.7% of antigens in cosmetic series were found to be in the cosmetics sampled. Conclusion The constituents not included in the patch test but possess antigenicity are widely used in cosmetics. Therefore, the patch test should be modified to reflect ingredients in the marketed products that may stimulate allergies. PMID:20711261
Rivoire, Becky L.; Groathouse, Nathan A.; TerLouw, Stephen; Neupane, Kapil Dev; Ranjit, Chaman; Sapkota, Bishwa Raj; Khadge, Saraswoti; Kunwar, Chatra B.; Macdonald, Murdo; Hawksworth, Rachel; Thapa, Min B.; Hagge, Deanna A.; Tibbals, Melinda; Smith, Carol; Dube, Tina; She, Dewei; Wolff, Mark; Zhou, Eric; Makhene, Mamodikoe; Mason, Robin; Sizemore, Christine; Brennan, Patrick J.
Background New tools are required for the diagnosis of pre-symptomatic leprosy towards further reduction of disease burden and its associated reactions. To address this need, two new skin test antigens were developed to assess safety and efficacy in human trials. Methods A Phase I safety trial was first conducted in a non-endemic region for leprosy (U.S.A.). Healthy non-exposed subjects (n = 10) received three titrated doses (2.5 µg, 1.0 µg and 0.1 µg) of MLSA-LAM (n = 5) or MLCwA (n = 5) and control antigens [Rees MLSA (1.0 µg) and saline]. A randomized double blind Phase II safety and efficacy trial followed in an endemic region for leprosy (Nepal), but involved only the 1.0 µg (high dose) and 0.1 µg (low dose) of each antigen; Tuberculin PPD served as a control antigen. This Phase II safety and efficacy trial consisted of three Stages: Stage A and B studies were an expansion of Phase I involving 10 and 90 subjects respectively, and Stage C was then conducted in two parts (high dose and low dose), each enrolling 80 participants: 20 borderline lepromatous/lepromatous (BL/LL) leprosy patients, 20 borderline tuberculoid/tuberculoid (BT/TT) leprosy patients, 20 household contacts of leprosy patients (HC), and 20 tuberculosis (TB) patients. The primary outcome measure for the skin test was delayed type hypersensitivity induration. Findings In the small Phase I safety trial, reactions were primarily against the 2.5 µg dose of both antigens and Rees control antigen, which were then excluded from subsequent studies. In the Phase II, Stage A/B ramped-up safety study, 26% of subjects (13 of 50) showed induration against the high dose of each antigen, and 4% (2 of 50) reacted to the low dose of MLSA-LAM. Phase II, Stage C safety and initial efficacy trial showed that both antigens at the low dose exhibited low sensitivity at 20% and 25% in BT/TT leprosy patients, but high specificity at 100% and 95% compared to TB patients. The high dose of both antigens
Sapatnekar, Suneeti; Figueroa, Priscilla I
The molecular basis of many blood group antigens is known, and it provides a means for predicting the red blood cell phenotype. Molecular typing methods are useful when serologic typing cannot be performed, due to sample or reagent limitations. We discuss the implementation of a commercial molecular typing assay at our Transfusion Service, the indications for testing, and the advantages and drawbacks of the assay. We also present our algorithm for selecting candidates for testing.
Coulibaly, Jean T.; N'Gbesso, Yves K.; Knopp, Stefanie; N'Guessan, Nicaise A.; Silué, Kigbafori D.; van Dam, Govert J.; N'Goran, Eliézer K.; Utzinger, Jürg
Background The Kato-Katz technique is widely used for the diagnosis of Schistosoma mansoni, but shows low sensitivity in light-intensity infections. We assessed the accuracy of a commercially available point-of-care circulating cathodic antigen (POC-CCA) cassette test for the diagnosis of S. mansoni in preschool-aged children before and after praziquantel administration. Methodology A 3-week longitudinal survey with a treatment intervention was conducted in Azaguié, south Côte d'Ivoire. Overall, 242 preschoolers (age range: 2 months to 5.5 years) submitted two stool and two urine samples before praziquantel administration, and 86 individuals were followed-up posttreatment. Stool samples were examined with duplicate Kato-Katz thick smears for S. mansoni. Urine samples were subjected to POC-CCA cassette test for S. mansoni, and a filtration method for S. haematobium diagnosis. Principal Findings Before treatment, the prevalence of S. mansoni, as determined by quadruplicate Kato-Katz, single CCA considering ‘trace’ as negative (t−), and single CCA with ‘trace’ as positive (t+), was 23.1%, 34.3% and 64.5%, respectively. Using the combined results (i.e., four Kato-Katz and duplicate CCA(t−)) as diagnostic ‘gold’ standard, the sensitivity of a single Kato-Katz, a single CCA(t−) or CCA(t+) was 28.3%, 69.7% and 89.1%, respectively. Three weeks posttreatment, the sensitivity of a single Kato-Katz, single CCA(t−) and CCA(t+) was 4.0%, 80.0% and 84.0%, respectively. The intensity of the POC-CCA test band reaction was correlated with S. mansoni egg burden (odds ratio = 1.2, p = 0.04). Conclusions/Significance A single POC-CCA cassette test appears to be more sensitive than multiple Kato-Katz thick smears for the diagnosis of S. mansoni in preschool-aged children before and after praziquantel administration. The POC-CCA cassette test can be recommended for the rapid identification of S. mansoni infections before treatment. Additional studies are
Oka, Hideaki; Ueda, Atsuhisa; Watanuki, Yuji; Tsukiji, Jun; Kuroda, Hideyo; Akashi, Syunsuke; Hirai, Yoshihiro; Fuyuki, Toshiharu; Kaneko, Takeshi; Ishigatsubo, Yoshiaki
We analyzed the efficacy of both the Streptococcus pneumoniae urine antigen test as a quick diagnostic tool and the administration of high-dose penicillin in response to a positive S. pneumoniae urine antigen test. We conducted a retrospective analysis of 48 cases of pneumococcal pneumonia, in which the patients were treated with high-dose penicillin. All the cases were diagnosed by a positive urine antigen test. Treatment with high-dose penicillin was effective in 43 of the 48 patients. This treatment was also effective in 12 of 16 culture-confirmed cases with low susceptibility to penicillin. Eleven patients who were positive for the S. pneumoniae urine antigen test but culture-negative showed clinical improvement with high-dose penicillin. Pneumonia caused by S. pneumoniae appeared to be treated safely and effectively with high-dose penicillin based on positive results of the urine antigen test, as penicillin resistance was unlikely to be a problem.
Cost-Effective and Rapid Presumptive Identification of Gram-Negative Bacilli in Routine Urine, Pus, and Stool Cultures: Evaluation of the Use of CHROMagar Orientation Medium in Conjunction with Simple Biochemical Tests
The algorithm for a new identification system was designed on the basis of colony color and morphology on CHROMagar Orientation medium in conjunction with simple biochemical tests such as indole (IND), lysine decarboxylase (LDC), and ornithine decarboxylase (ODC) utilization tests with gram-negative bacilli isolated from urine samples as well as pus, stool, and other clinical specimens by the following colony characteristics, biochemical reactions, and serological results: pinkish to red, IND positive (IND+), Escherichia coli; metallic blue, IND+, LDC+, and ODC negative (ODC−), Klebsiella oxytoca; IND+, LDC−, and ODC+, Citrobacter diversus; IND+ or IND−, LDC−, and ODC−, Citrobacter freundii; IND−, LDC+, and ODC+, Enterobacter aerogenes; IND−, LDC−, and ODC+, Enterobacter cloacae; IND−, LDC+, and ODC−, Klebsiella pneumoniae; diffuse brown and IND+, Morganella morganii; IND−, Proteus mirabilis; aqua blue, Serratia marcescens; bluish green and IND+, Proteus vulgaris; transparent yellow-green, serology positive, Pseudomonas aeruginosa; clear and serology positive, Salmonella sp.; other colors and reactions, the organism was identified by the full identification methods. The accuracy and cost-effectiveness of this new system were prospectively evaluated. During an 8-month period, a total of 345 specimens yielded one or more gram-negative bacilli. A total of 472 gram-negative bacillus isolates were detected on CHROMagar Orientation medium. For 466 of the isolates (98.7%), no discrepancies in the results were obtained on the basis of the identification algorithm. The cost of identification of gram-negative bacilli during this period was reduced by about 70%. The results of this trial for the differentiation of the most commonly encountered gram-negative pathogens in clinical specimens with the new algorithm were favourable in that it permitted reliable detection and presumptive identification. In addition, this rapid identification system not only
Cost-effective and rapid presumptive identification of gram-negative bacilli in routine urine, pus, and stool cultures: evaluation of the use of CHROMagar orientation medium in conjunction with simple biochemical tests.
The algorithm for a new identification system was designed on the basis of colony color and morphology on CHROMagar Orientation medium in conjunction with simple biochemical tests such as indole (IND), lysine decarboxylase (LDC), and ornithine decarboxylase (ODC) utilization tests with gram-negative bacilli isolated from urine samples as well as pus, stool, and other clinical specimens by the following colony characteristics, biochemical reactions, and serological results: pinkish to red, IND positive (IND(+)), Escherichia coli; metallic blue, IND(+), LDC(+), and ODC negative (ODC(-)), Klebsiella oxytoca; IND(+), LDC(-), and ODC(+), Citrobacter diversus; IND(+) or IND(-), LDC(-), and ODC(-), Citrobacter freundii; IND(-), LDC(+), and ODC(+), Enterobacter aerogenes; IND(-), LDC(-), and ODC(+), Enterobacter cloacae; IND(-), LDC(+), and ODC(-), Klebsiella pneumoniae; diffuse brown and IND(+), Morganella morganii; IND(-), Proteus mirabilis; aqua blue, Serratia marcescens; bluish green and IND(+), Proteus vulgaris; transparent yellow-green, serology positive, Pseudomonas aeruginosa; clear and serology positive, Salmonella sp.; other colors and reactions, the organism was identified by the full identification methods. The accuracy and cost-effectiveness of this new system were prospectively evaluated. During an 8-month period, a total of 345 specimens yielded one or more gram-negative bacilli. A total of 472 gram-negative bacillus isolates were detected on CHROMagar Orientation medium. For 466 of the isolates (98.7%), no discrepancies in the results were obtained on the basis of the identification algorithm. The cost of identification of gram-negative bacilli during this period was reduced by about 70%. The results of this trial for the differentiation of the most commonly encountered gram-negative pathogens in clinical specimens with the new algorithm were favourable in that it permitted reliable detection and presumptive identification. In addition, this rapid
Ivanoska, D.; Cuperlovic, K.; Gamble, H.R.; Murrell, K.D.
Sera collected from patients with suspected or confirmed exposure to Trichinella spiralis were tested for circulating parasite antigens and antiparasite antibodies. Using an immunoradiometric assay, excretory--secretory antigens from muscle-stage larvae of T. spiralis were detected in the sera of 47% of 62 patients with clinical trichinellosis and 13% of 39 patients without clinical signs but suspected of exposure to infected meat. In comparison, antibodies were detected using an indirect immunofluorescent test in the circulation of 100% of the 62 patients with clinical trichinellosis and 46% of the 39 patients with suspected exposure. The presence of antibodies specific to excretory-secretory products of T. spiralis muscle larvae was confirmed in the majority of the samples tested by a monoclonal antibody-based competitive inhibition assay. These results indicate that antibody detection is a more sensitive diagnostic method for human trichinellosis, but that antigen detection might be a useful confirmatory test because it is a direct demonstration of parasite products in the circulation.
... to treat pregnancy constipation? Answers from Roger W. Harms, M.D. Stool softeners are generally considered safe ... easier to pass. These products are unlikely to harm a developing baby because their active ingredient is ...
Trask, J D; Paul, J R; Vignec, A J
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.
Wilson, Deborah A; Sholtis, Mary; Parshall, Sharon; Hall, Gerri S; Procop, Gary W
A total of 52 residual CSF and serum specimens, which were originally negative with the Cryptococcal Antigen Latex Agglutination System (CALAS), were shown to become falsely positive after placement in BBL Port-A-Cul anaerobic transport vials. This transport device, although excellent for specimen transportation for subsequent culture, should not be used if cryptococcal antigen testing is needed.
Martinez, B; Crews, E; Dowd, A; M McMahan, M
Donor RBCs nonreactive in initial tests for D must be tested further for evidence of weak expression of D antigen. Performing this test in test tubes is labor intensive and prone to inconsistencies in readings (relative strength of agglutination) and interpretation (positive versus negative). These inconsistencies can lead to repeat testing, additional documentation, and delay in releasing units. We evaluated use of the Tecan MEGAFlex-ID pipettor to perform this test in anti-IgG gel cards. Results with this semi-automated gel test were compared with results obtained with 37 D- and 99 weak D samples, as determined by previous testing with a manual IAT tube test. Hands-on time was determined for both methods and both methods were evaluated for inconsistency, or nonagreement, between the interpretation of the current weak D test and the results on record for any prior donations. There were no discordant results obtained, with the majority of weak D samples giving stronger reactions with the gel test. The semiautomated gel test required less hands-on time, with an average savings of more than 70 seconds per test. There were no inconsistencies with the gel method, whereas manual tube testing was found to have an inconsistency rate of 0.035 percent of total samples tested. Semiautomated IgG gel is now used for all weak D testing, with a labor savings of more than 10 hours per week. Thus far, more than 70,000 donors have been tested, with no inconsistencies reported.
Shepherd, A J; Hummitzsch, D E; Leman, P A; Swanepoel, R; Searle, L A
The enzyme-linked immunosorbent assay (ELISA) was compared with other standard tests for detection of plague (Yersinia pestis) antibody and antigen in multimammate mice (Mastomys coucha and M. natalensis) which were experimentally infected and then killed at daily intervals postinoculation. For detection of antibody in sera from M. natalensis, the immunoglobulin G (IgG) ELISA was equivalent in sensitivity to passive hemagglutination and more sensitive than the IgM ELISA and complement fixation. Antibody was first detected on postinfection day 6 by all four tests, but IgM ELISA titers had declined to undetectable levels after 8 weeks. For detection of fraction 1 Y. pestis antigen in rodent organs, the ELISA was less sensitive than fluorescent antibody but more sensitive than complement fixation or immunodiffusion. Plague fraction 1 antigen was detected in 16 of 34 bacteremic sera from M. coucha and M. natalensis. The threshold sensitivity of the ELISA was approximately 10(5) Y. pestis per ml. PMID:3097065
van Dam, G. J.; Wichers, J. H.; Ferreira, T. M. Falcao; Ghati, D.; van Amerongen, A.; Deelder, A. M.
A newly developed reagent strip assay for the diagnosis of schistosomiasis based on parasite antigen detection in urine of infected individuals was evaluated. The test uses the principle of lateral flow through a nitrocellulose strip of the sample mixed with a colloidal carbon conjugate of a monoclonal antibody specific for Schistosoma circulating cathodic antigen (CCA). The strip assay to diagnose a group of highly infected schoolchildren in Mwanza, Tanzania, demonstrated a high sensitivity and association with the intensity of infection as measured both by egg counts, and by circulating anodic antigen and CCA levels determined by enzyme-linked immunosorbent assay. A specificity of ca. 90% was shown in a group of schistosome-negative schoolchildren from Tarime, Tanzania, an area where schistosomiasis is not endemic. The test is easy to perform and requires no technical equipment or special training. The stability of the strips and the conjugate in the dry format lasts for at least 3 months at ambient temperature in sealed packages, making it suitable for transport and use in areas where schistosomiasis is endemic. This assay can easily be developed to an end-user format. PMID:15583265
Ortu, Giuseppina; Ndayishimiye, Onésime; Clements, Michelle; Kayugi, Donatien; Campbell, Carl H.; Lamine, Mariama Sani; Zivieri, Antonio; Magalhaes, Ricardo Soares; Binder, Sue; King, Charles H.; Fenwick, Alan; Colley, Daniel G.; Jourdan, Peter Mark
Following implementation of the national control program, a reassessment of Schistosoma mansoni prevalence was conducted in Burundi to determine the feasibility of moving toward elimination. A countrywide cluster-randomized cross-sectional study was performed in May 2014. At least 25 schools were sampled from each of five eco-epidemiological risk zones for schistosomiasis. Fifty randomly selected children 13–14 years of age per school were included for a single urine-circulating cathodic antigen (CCA) rapid test and, in a subset of schools, for duplicate Kato-Katz slide preparation from a single stool sample. A total of 17,331 children from 347 schools were tested using CCA. The overall prevalence of S. mansoni infection, when CCA trace results were considered negative, was 13.5% (zone range [zr] = 4.6–17.8%), and when CCA trace results were considered positive, it was 42.8% (zr = 34.3–49.9%). In 170 schools, prevalence of this infection determined using Kato-Katz method was 1.5% (zr ==0–2.7%). The overall mean intensity of S. mansoni infection determined using Kato-Katz was 0.85 eggs per gram (standard deviation = 10.86). A majority of schools (84%) were classified as non-endemic (prevalence = 0) using Kato-Katz; however, a similar proportion of schools were classified as endemic when CCA trace results were considered negative (85%) and nearly all (98%) were endemic when CCA trace results were considered positive. The findings of this nationwide reassessment using a CCA rapid test indicate that Schistosoma infection is still widespread in Burundi, although its average intensity is probably low. Further evidence is now needed to determine the association between CCA rapid test positivity and low-intensity disease transmission. PMID:28115675
Ortu, Giuseppina; Ndayishimiye, Onésime; Clements, Michelle; Kayugi, Donatien; Campbell, Carl H; Lamine, Mariama Sani; Zivieri, Antonio; Magalhaes, Ricardo Soares; Binder, Sue; King, Charles H; Fenwick, Alan; Colley, Daniel G; Jourdan, Peter Mark
Following implementation of the national control program, a reassessment of Schistosoma mansoni prevalence was conducted in Burundi to determine the feasibility of moving toward elimination. A countrywide cluster-randomized cross-sectional study was performed in May 2014. At least 25 schools were sampled from each of five eco-epidemiological risk zones for schistosomiasis. Fifty randomly selected children 13-14 years of age per school were included for a single urine-circulating cathodic antigen (CCA) rapid test and, in a subset of schools, for duplicate Kato-Katz slides preparation from a single stool sample. A total of 17,331 children from 347 schools were tested using CCA. The overall prevalence of S. mansoni infection, when CCA trace results were considered negative, was 13.5% (zone range [zr] = 4.6-17.8%), and when CCA trace results were considered positive, it was 42.8% (zr = 34.3-49.9%). In 170 schools, prevalence of this infection determined using Kato-Katz method was 1.5% (zr ==0-2.7%). The overall mean intensity of S. mansoni infection determined using Kato-Katz was 0.85 eggs per gram (standard deviation = 10.86). A majority of schools (84%) were classified as non-endemic (prevalence = 0) using Kato-Katz; however, a similar proportion of schools were classified as endemic when CCA trace results were considered negative (85%) and nearly all (98%) were endemic when CCA trace results were considered positive. The findings of this nationwide reassessment using CCA rapid test indicate that Schistosoma infection is still widespread in Burundi, although its average intensity is probably low. Further evidence is now needed to determine the association between CCA rapid test positivity and low-intensity disease transmission.
Khare, Reeti; Espy, Mark J; Cebelinski, Elizabeth; Boxrud, David; Sloan, Lynne M; Cunningham, Scott A; Pritt, Bobbi S; Patel, Robin; Binnicker, Matthew J
The detection of pathogens associated with gastrointestinal disease may be important in certain patient populations, such as immunocompromised hosts, the critically ill, or individuals with prolonged disease that is refractory to treatment. In this study, we evaluated two commercially available multiplex panels (the FilmArray gastrointestinal [GI] panel [BioFire Diagnostics, Salt Lake City, UT] and the Luminex xTag gastrointestinal pathogen panel [GPP] [Luminex Corporation, Toronto, Canada]) using Cary-Blair stool samples (n = 500) submitted to our laboratory for routine GI testing (e.g., culture, antigen testing, microscopy, and individual real-time PCR). At the time of this study, the prototype (non-FDA-cleared) FilmArray GI panel targeted 23 pathogens (14 bacterial, 5 viral, and 4 parasitic), and testing of 200 μl of Cary-Blair stool was recommended. In contrast, the Luminex GPP assay was FDA cleared for the detection of 11 pathogens (7 bacterial, 2 viral, and 2 parasitic), but had the capacity to identify 4 additional pathogens using a research-use-only protocol. Importantly, the Luminex assay was FDA cleared for 100 μl raw stool; however, 100 μl Cary-Blair stool was tested by the Luminex assay in this study. Among 230 prospectively collected samples, routine testing was positive for one or more GI pathogens in 19 (8.3%) samples, compared to 76 (33.0%) by the FilmArray and 69 (30.3%) by the Luminex assay. Clostridium difficile (12.6 to 13.9% prevalence) and norovirus genogroup I (GI)/GII (5.7 to 13.9% prevalence) were two of the pathogens most commonly detected by both assays among prospective samples. Sapovirus was also commonly detected (5.7% positive rate) by the FilmArray assay. Among 270 additional previously characterized samples, both multiplex panels demonstrated high sensitivity (>90%) for the majority of targets, with the exception of several pathogens, notably Aeromonas sp. (23.8%) by FilmArray and Yersinia enterocolitica (48.1%) by the Luminex
Pontoizeau, C.; Dangers, L.; Jarlier, V.; Luyt, C. E.; Guiller, E.; Fievet, M. H.; Lecsö-Bornet, M.; Aubry, A.
We report here false-positive urinary Legionella pneumophila serogroup 1 and Streptococcus pneumoniae antigen test results due to rabbit antilymphocyte serum treatment and provide a simple and fast solution to rule them out by heating urine. PMID:25253788
Aliannejad, Rasoul; Bahrmand, Ahmadreza; Abtahi, Hamidreza; Seifi, Mahnaz; Safavi, Enayat; Abdolrahimi, Farid; Shahriaran, Shahriyar
Background and Objectives: Tuberculosis (TB) is a major problem in the world. Treatment and control of TB needs detection of the Mycobacterium tuberculosis (MT) in the proper samples. While smear doesn’t have enough sensitivity, culture and PCR are expensive, time consuming and unavailable in many centers. Recent development of a rapid TB antigen detection test (PrTBK) at Pasteur Institute of Iran could give a simple way for diagnosis of TB in about two hours. In this test the antigen-antibody complex will change color when gold conjugated mouse anti-rabbit antibody detects specific MT cell wall antigen in suspected samples. Materials and Methods: We evaluated the diagnostic accuracy of PrTBK for diagnosis of pulmonary TB in comparison with smear, culture and PCR techniques in 56 consecutive samples (47 BAL and 13 sputum samples) obtained from patients with clinical suspicion of active TB. Results: Twentynine patients (52%) were female and seven patients were HIV positive. PrTBK was positive in 17 culture positive and 4 culture negative samples (100% sensitivity, 89% specificity and 92% accuracy in comparison with culture method). In two out of four patients with negative culture who were positive for PrTBK, PCR and anti-tuberculosis drugs trial therapy responses were in favor of tuberculosis. If we take this finding into account, the accuracy of PrTBK will rise. Conclusion: High sensitivity and accuracy of PrTBK test enable us to initiate treatment on the basis of this convenient and rapid test. PMID:28210462
Li, Wen-han; Zhang, Hao; Guo, Qi; Wu, Xuan-di; Xu, Zi-sen; Dang, Cheng-xue; Xia, Peng; Song, Yong-chun
Aim. We examined the methylation status of SNCA and FBN1 genes in patients' paired tissue and stool samples for detection of colorectal cancer (CRC). Patients and Methods. 89 DNA tissue samples (normal/cancer) and corresponding stool samples were analyzed in our study. In addition, 30 stool samples were collected as healthy controls. Results. The methylation level of those samples was measured by methylation-specific polymerase chain reaction (MSP). The result shows that compared with the paired controls, both SNCA and FBN1 were significantly hypermethylated in CRC patients in tissue samples (P < 0.001). In the stool samples, hypermethylated SNCA and FBN1 were detected to be significantly higher than that in normal stool samples (P < 0.001). The combined sensitivity of at least one positive among the two markers in stool samples was 84.3%, with a specificity of 93.3%. In addition, our experiment suggested that the positive rates of SNCA and FBN1 in Dukes A stage were significantly higher than that of FOBT (P = 0.039; P = 0.006, resp.). Conclusion. We concluded that methylation testing of SNCA and FBN1 genes in stool sample may offer a good alternative in a simple, promising, and noninvasive detection of colorectal cancer. PMID:25802477
Haddad, Diana; Bilcikova, Erika; Witney, Adam A; Carlton, Jane M; White, Charles E; Blair, Peter L; Chattopadhyay, Rana; Russell, Joshua; Abot, Esteban; Charoenvit, Yupin; Aguiar, Joao C; Carucci, Daniel J; Weiss, Walter R
We describe a novel approach for identifying target antigens for preerythrocytic malaria vaccines. Our strategy is to rapidly test hundreds of DNA vaccines encoding exons from the Plasmodium yoelii yoelii genomic sequence. In this antigen identification method, we measure reduction in parasite burden in the liver after sporozoite challenge in mice. Orthologs of protective P. y. yoelii genes can then be identified in the genomic databases of Plasmodium falciparum and Plasmodium vivax and investigated as candidate antigens for a human vaccine. A pilot study to develop the antigen identification method approach used 192 P. y. yoelii exons from genes expressed during the sporozoite stage of the life cycle. A total of 182 (94%) exons were successfully cloned into a DNA immunization vector with the Gateway cloning technology. To assess immunization strategies, mice were vaccinated with 19 of the new DNA plasmids in addition to the well-characterized protective plasmid encoding P. y. yoelii circumsporozoite protein. Single plasmid immunization by gene gun identified a novel vaccine target antigen which decreased liver parasite burden by 95% and which has orthologs in P. vivax and P. knowlesi but not P. falciparum. Intramuscular injection of DNA plasmids produced a different pattern of protective responses from those seen with gene gun immunization. Intramuscular immunization with plasmid pools could reduce liver parasite burden in mice despite the fact that none of the plasmids was protective when given individually. We conclude that high-throughput cloning of exons into DNA vaccines and their screening is feasible and can rapidly identify new malaria vaccine candidate antigens.
The Wisconsin Division of Public Health and the Wisconsin State Laboratory of Hygiene (WSLH) reported that a recent cluster of cryptosporidiosis cases in a three-county area in southeastern Wisconsin was the result of false-positive tests. During December 1, 2001-February 1, 2002, approximately 30 cases of cryptosporidiosis were diagnosed at a laboratory in southeastern Wisconsin using the Becton, Dickinson, and Company (Franklin Lakes, New Jersey) ColorPAC Cryptosporidium/Giardia rapid assay (lot number 219370, expiration date 2002-06-05). Seventeen stool specimens, which were collected from 11 patients and tested positive by the rapid assay, were re-evaluated at WSLH. Six of these stool specimens were in EcoFix (Meridian Bioscience Inc., Cincinnati, Ohio), eight were in Cary-Blair transport media, and three were formalin fixed. All 17 specimens tested negative for Cryptosporidium at WSLH using the hot safranin stain and MeriFluor (Meridian Bioscience Inc., Cincinnati, Ohio) Cryptosporidium/Giardia direct fluorescent antibody kit with concentrated specimens.
Docters, E. H.; Smolko, E. E.; Suarez, C. E.
The radiation grafting process has a wide field of industrial applications, and in the recent years the immobilization of biocomponents in grafted polymeric materials obtained by means of ionizing radiations is a new and important contribution to biotechnology. In the present work, gamma preirradiation grafting method was employed to produce acrylics hydrogels onto polyethylene (PE), polyvinyl chloride (PVC) and polystyrene (PS). Two monomers were used to graft the previously mentioned polymers: methacrylic acid (MAAc) and acrylamide (AAm), and several working conditions were considered as influencing the degree of grafting. All this grafted polymers were used to study the possibility of a subsequent immobilization of Brucella antigen (BAg) in diagnostic test studies (ELISA).
Jørgensen, Charlotte S; Uldum, Søren A; Sørensen, Jesper F; Skovsted, Ian C; Otte, Sanne; Elverdal, Pernille L
Pneumonia is a major cause of morbidity and mortality worldwide. Early diagnosis of the etiologic agent is important in order to choose the correct antibiotic treatment. In this study we evaluated the first commercial combined test for the agents of pneumococcal pneumonia and Legionnaires' disease based on urinary antigen detection, the ImmuView® Streptococcus pneumoniae and Legionella pneumophila Urinary Antigen Test. In this evaluation, the new test had a significantly higher sensitivity than the BinaxNOW® lateral flow tests and the Binax® EIA test. This identifies the ImmuView® S. pneumoniae and L. pneumophila Urinary Antigen Test as a fast and sensitive point of care test for identification of the infectious agent in a major group of patients with pneumonia.
Mott, K. E.; Dixon, H.
Eight research laboratories in Europe and the United States of America were selected on the basis of having published data on Schistosoma mansoni and S. japonicum antigens to participate in a study of various antigen/test combinations for immunodiagnosis of schistosomiasis. The serum bank consisted of 395 well documented sera from four endemic areas in Brazil (2 areas), Kenya, and the Philippines. Altogether, 21 S. mansoni and four S. japonicum antigen and immunoassay combinations were evaluated. S. mansoni egg antigens yielded a higher combined sensitivity than adult worm antigens, irrespective of their purity, in active S. mansoni infections before and after specific treatment. Quantitative seroreactivity of characterized S. mansoni egg antigens showed good correlation with faecal egg counts in the 5-14 year age group. No correlation between morbidity related to S. mansoni and seroreactivity was observed in any test system. Three S. japonicum egg antigens showed high sensitivity and specificity in relation to the presence or absence of eggs in the stool. The quantitative seroreactivity of the characterized S. japonicum egg antigens correlated directly with the intensity of S. japonicum infection in all age groups. The enzyme-linked immunosorbent assay (ELISA), using several different procedures, performed well with the antigens used in the study. The indium slide immunoassay (ISI), a simple qualitative visual test system using an S. mansoni egg antigen, demonstrated a high degree of sensitivity and specificity. The results did not indicate the superiority of any particular immunodiagnostic method for detecting antischistosome antibodies. This collaborative study is considered a first step towards developing and standardizing antigens for immunodiagnosis of schistosomiasis. PMID:6983926
Montecalvo, Marisa A; Sisay, Emnet; McKenna, Donna; Wang, Guiqing; Visintainer, Paul; Wormser, Gary P
OBJECTIVE To evaluate the use of a perianal swab to detect CDI. METHODS A perianal swab was collected from each inpatient with a positive stool sample for C. difficile (by polymerase chain reaction [PCR] test) and was tested for C. difficile by PCR and by culture. The variables evaluated included demographics, CDI severity, bathing before perianal swab collection, hours between stool sample and perianal swab, cycle threshold (Ct) to PCR positivity, and doses of CDI treatment before stool sample and before perianal swab. RESULTS Of 83 perianal swabs, 59 (71.1%) tested positive for C. difficile by PCR when perianal swabs were collected an average of 21 hours after the stool sample. Compared with the respective stool sample, the perianal sample was less likely to grow C. difficile (P=.005) and had a higher PCR Ct (P<.001). A direct, significant but weak correlation was detected between the Ct for a positive perianal sample and the respective stool sample (r=0.36; P=.006). An inverse dose relationship was detected between PCR positivity and CDI treatment doses before perianal swab collection (P=.27). CONCLUSION Perianal swabs are a simple method to detect C. difficile tcdB gene by PCR, with a sensitivity of 71%. These data were limited because stool samples and perianal swabs were not collected simultaneously. Compared with stool samples, the perianal Ct values and culture results were consistent with a lower bacterial load on the perianal sample due to the receipt of more CDI treatment before collection or unknown factors affecting perianal skin colonization. Infect Control Hosp Epidemiol 2017;1-5.
Crannell, Zachary Austin; Cabada, Miguel Mauricio; Castellanos-Gonzalez, Alejandro; Irani, Ayesha; White, Arthur Clinton; Richards-Kortum, Rebecca
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.
Nderitu, Paul; Van Hemelrijck, Mieke; Ashworth, Mark; Mathur, Rohini; Hull, Sally; Dudek, Alexandra; Chowdhury, Simon
Objectives To investigate the association between factors influencing prostate-specific antigen (PSA) testing prevalence including prostate cancer risk factors (age, ethnicity, obesity) and non-risk factors (social deprivation and comorbidity). Setting A cross-sectional database of 136 inner London general practices from 1 August 2009 to 31 July 2014. Participants Men aged ≥40 years without prostate cancer were included (n=150 481). Primary outcome Logistic regression analyses were used to estimate the association between PSA testing and age, ethnicity, social deprivation, body mass index (BMI) and comorbidity while adjusting for age, benign prostatic hypertrophy, prostatitis and tamsulosin or finasteride use. Results PSA testing prevalence was 8.2% (2013–2014), and the mean age was 54 years (SD 11). PSA testing was positively associated with age (OR 70–74 years compared to 40–44 years: 7.34 (95% CI 6.82 to 7.90)), ethnicity (black) (OR compared to white: 1.78 (95% CI 1.71 to 1.85)), increasing BMI and cardiovascular comorbidity. Testing was negatively associated with Chinese ethnicity and with increasing social deprivation. Conclusions PSA testing among black patients was higher compared to that among white patients, which differs from lower testing rates seen in previous studies. PSA testing was positively associated with prostate cancer risk factors and non-risk factors. Association with non-risk factors may increase the risk of unnecessary invasive diagnostic procedures. PMID:27406644
Okabayashi, Tamaki; Sasaki, Tadahiro; Masrinoul, Promsin; Chantawat, Nantarat; Yoksan, Sutee; Nitatpattana, Narong; Chusri, Sarunyou; Morales Vargas, Ronald E; Grandadam, Marc; Brey, Paul T; Soegijanto, Soegeng; Mulyantno, Kris Cahyo; Churrotin, Siti; Kotaki, Tomohiro; Faye, Oumar; Faye, Ousmane; Sow, Abdourahmane; Sall, Amadou Alpha; Puiprom, Orapim; Chaichana, Panjaporn; Kurosu, Takeshi; Kato, Seiji; Kosaka, Mieko; Ramasoota, Pongrama; Ikuta, Kazuyoshi
Chikungunya fever is a mosquito-borne disease of key public health importance in tropical and subtropical countries. Although severe joint pain is the most distinguishing feature of chikungunya fever, diagnosis remains difficult because the symptoms of chikungunya fever are shared by many pathogens, including dengue fever. The present study aimed to develop a new immunochromatographic diagnosis test for the detection of chikungunya virus antigen in serum. Mice were immunized with isolates from patients with Thai chikungunya fever, East/Central/South African genotype, to produce mouse monoclonal antibodies against chikungunya virus. Using these monoclonal antibodies, a new diagnostic test was developed and evaluated for the detection of chikungunya virus. The newly developed diagnostic test reacted with not only the East/Central/South African genotype but also with the Asian and West African genotypes of chikungunya virus. Testing of sera from patients suspected to have chikungunya fever in Thailand (n = 50), Laos (n = 54), Indonesia (n = 2), and Senegal (n = 6) revealed sensitivity, specificity, and real-time PCR (RT-PCR) agreement values of 89.4%, 94.4%, and 91.1%, respectively. In our study using serial samples, a new diagnostic test showed high agreement with the RT-PCR within the first 5 days after onset. A rapid diagnostic test was developed using mouse monoclonal antibodies that react with chikungunya virus envelope proteins. The diagnostic accuracy of our test is clinically acceptable for chikungunya fever in the acute phase.
Yeow, Natasha; McLiesh, Heather; Guan, Liyun; Shen, Wei; Garnier, Gil
A rapid and simple paper-based elution assay for red blood cell antigen typing by the indirect antiglobulin test (IAT) was established. This allows to type blood using IgG antibodies for the important blood groups in which IgM antibodies do not exist. Red blood cells incubated with IgG anti-D were washed with saline and spotted onto the paper assay pre-treated with anti-IgG. The blood spot was eluted with an elution buffer solution in a chromatography tank. Positive samples were identified by the agglutinated and fixed red blood cells on the original spotting area, while red blood cells from negative samples completely eluted away from the spot of origin. Optimum concentrations for both anti-IgG and anti-D were identified to eliminate the washing step after the incubation phase. Based on the no-washing procedure, the critical variables were investigated to establish the optimal conditions for the paper-based assay. Two hundred ten donor blood samples were tested in optimal conditions for the paper test with anti-D and anti-Kell. Positive and negative samples were clearly distinguished. This assay opens up new applications of the IAT on paper including antibody detection and blood donor-recipient crossmatching and extends its uses into non-blood typing applications with IgG antibody-based diagnostics. Graphical abstract A rapid and simple paper-based assay for red blood cell antigen typing by the indirect antiglobulin test.
Çetiner, Salih; Çetin Duran, Alev; Kibar, Filiz; Yaman, Akgün
The study has evaluated the performance of HCV core antigen (Cag) test by comparing HCV RNA PCR assay which is considered the gold standard for management of HCV infection. Totally, 132 samples sent for HCV RNA (real-time PCR) test were included in the study. Anti-HCV antibody test and HCV Cag test were performed by chemiluminescent enzyme immunoassay (CMEI). Anti-HCV test was positive in all samples. HCV RNA was detected in 112/132 (84.8%) samples, and HCV Cag in 105/132 (79.5%). The most common HCV genotype was genotype 1 (86%). Considering the HCV RNA test as gold standard; the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of Cag test were found to be 93.75%, 100%, 100%, 74.07% and 94.69%, respectively, and paired test results were detected as highly concordant. A high level of correlation was seen between HCV RNA and Cag tests, however, the concordance between the two tests appeared to be disrupted at viral loads lower than 10(3)IU/mL. On the contrary, the correlation reached significance for the values higher than 10(3)IU/mL. Viral loads were in the 17-2500IU/mL range for the negative results for Cag test. Pearson's correlation coefficient revealed a considerably high correlation. The concordance between HCV RNA and Cag tests was disrupted under a viral load lower than 10(3)IU/mL. Therefore, it would be appropriate to consider cost effectiveness, advantages and limitations of the HCV RNA and Cag tests during the decision on which method to use for patient management.
Das, L K; Pani, S P; Vanamail, P; Vijayalakshmi, G; Debritto, L J
This study was focussed on identifying a cost-effective method for delimitation, monitoring and evaluation in bancroftian filariasis. Finger prick blood samples were collected between 20.00 and 23.00 hours for the detection of microfilariae (mf) from the available population in a village which was endemic for lymphatic filariasis. Simultaneously, from each individual, four spots of 25-μl blood samples were collected on Whatman number 3 filter paper and air dried. Dried filter paper spots were pooled in quantities of 1, 5, 10, 15, 20 and 25 on unknown and simulated mf and antigen prevalence. Pooled samples were assayed for circulating filarial antigen (CFA) using TropBIO Og4C3 ELISA kits. The community mf and CFA rates were 3.4% and 25.9%, respectively. The pool sizes of 20 and 25 showed CFA positivity in all the above categories tested. The results of the pooled blood spot samples suggest that, in areas with mf and CFA prevalence rates between 1 and 10%, pools of 20 or 25 could be considered as the ideal pool size for the detection of filarial infection in the community. CFA prevalence at the level of 5-6% following desirable rounds of mass drug administration (MDA) indicates that the community mf prevalence is likely to be at the 1% level.
Vandeputte, Doris; Falony, Gwen; Vieira-Silva, Sara; Tito, Raul Y; Joossens, Marie; Raes, Jeroen
Objective 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. Design 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. Results 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. Conclusions 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. PMID:26069274
Risberg, Stefan; Engfeldt, Peter; Hugosson, Svante
The microbiological cause of peritonsillar abscess and the role of group A β-haemolytic Streptococcus (GAS) are unclear. We performed a retrospective study at the ear, nose and throat clinic (ENT) of Orebro University Hospital, Sweden, and included 376 events of peritonsillitis between 2002 and 2004. We determined if the patients had visited a primary healthcare centre (PHCC) within 30 days prior to inclusion. The results of the rapid antigen detection test for GAS (Strep A) taken at the PHCC were compared with the occurrence of peritonsillar abscess (PTA) and peritonsillar cellulitis (PTC). A Strep A test was performed in 61% (229/376) of the events studied. Strep A was positive in 22% of PTA events and in 35% of PTC events (p = 0.036). Of 48,000 Strep A tests taken in primary healthcare, mainly for sore throat, 22% were positive. We examined the relationship between age, the incidence of PTA, and positive Strep A tests. We also determined if there was a monthly correlation between number of positive Strep A tests and number of PTA events. We found no significant correlations. In conclusion, our findings indicate that GAS does not play a major role in the development of PTA/PTC.
Srinivasan, Ashok; Klepper, Corie; Sunkara, Anusha; Kang, Guolian; Carr, Jeanne; Gu, Zhengming; Leung, Wing; Hayden, Randall T.
Background Adenoviremia adversely affects prognosis in the post-hematopoietic stem cell transplant (HSCT) setting. Methods We sought to determine retrospectively the cutoff load of adenovirus in the stool as a predictor of adenoviremia, in children who underwent an allogeneic HSCT. The prevalence of sapovirus, norovirus and astrovirus in the stool was also studied. Results The study cohort consisted of 117 patients, of which 71 (60%) had diarrhea. Adenovirus was detected in the stool in 39 out of 71 (55%) patients. Age ≤ 10 years (P = 0.05; odds ratio, 2.57; 95% confidence interval: 0.98–6.75), and male sex (P = 0.04; odds ratio 2.67; 95% confidence interval: 1.02–6.99) increased risk for detection of adenovirus in stool on univariate analysis. Co-infections with enteric pathogens were infrequent. Viral load > 106 copies / gram stool predicted adenoviremia with a sensitivity and specificity of 82%. Sapovirus, norovirus, and astrovirus were detected in 3, 4 and one patient, respectively. Conclusions Quantitative detection of adenovirus in stool may have implications for pre-emptive therapy. Testing for other enteric viruses may have implications for infection control. PMID:25742243
Woś, Halina; Kordys-Darmolińska, Bożena; Sankiewicz-Szkółka, Magda; Grzybowska-Chlebowczyk, Urszula
Introduction Calprotectin is a protein that plays a regulatory role in inflammatory reactions as an antibacterial and antiproliferative factor. Aim To assess the concentration of calprotectin in the stools of patients with diagnosed cystic fibrosis. Material and methods Forty-one patients were included in the study, 24 boys and 17 girls, aged from 7 weeks to 18 years. The concentration of calprotectin in stools was assessed with the ELISA method. The analysis included clinical symptoms and the results of laboratory tests and the type of mutation. Results An elevated level of calprotectin in the stool was observed in 4/41 (9.7%) patients, mainly in older children, and mainly delta F508/deltaF508 mutation. The correlation between the concentration of calprotectin and clinical symptoms, age, increased indicators of an inflammatory process, levels of protein and aminotransferases in blood serum and the values of acid steatocrit of the stool was not proven. Conclusions High concentrations of calprotectin in the stools of children with diagnosed cystic fibrosis do not correlate with the level of advancement of lesions within the gastrointestinal tract. Elevated concentrations of calprotectin in the stools of patients with cystic fibrosis may indicate inflammation of intestine and should be further scrutinised.
O'Connor, O; Cooke, R P D; Cunliffe, N A; Pizer, B
Diarrhoea is a frequently occurring symptom in paediatric oncology patients. The role of routine testing for enteric bacteria in hospitalized patients with diarrhoea is considered limited, but the diagnostic value of testing in children with oncological conditions has not been reported. Therefore, we conducted a five-year retrospective service evaluation in our tertiary paediatric oncology unit together with a national survey of 21 centres to estimate the utility of stool cultures in oncology patients with diarrhoea and the national approach to testing. Our local survey demonstrated very low diagnostic yield using routine enteric stool cultures with only one sample out of 842 (0.1%) testing positive. The national survey demonstrated considerable variation in practice. There is little evidence to support the use of conventional stool culture for enteric bacteria in children with cancer in our centre. These findings should inform national testing policies.
Reynoso, G; Keane, M; Konopka, S
Forty-three laboratories participated in an interlaboratory testing program offered by the College of American Pathologists for the radioimmunoassay (RIA) of carcinoembryonic antigen (CEA). Thirty correctly reported a sample with 1.9 ng of endogenous CEA per ml as less than 2.5 ng. For samples with added exogenous CEA at the 5.4 ng/ml level, 24 laboratories reported too low and six too high (more than 2 SD beyond the targe value). At the 8.9 ng/ml concentration, three laboratories underestimated the CEA, while 18 overestimated the sample's concentration. A similar proportion of the laboratories performed in the same manner when estimating CEA at a target concentration of 15.9 ng/ml (five underestimating and 27 overestimating the concentration). Although individual variations were large, the majority of participating laboratories can reliably distinguish normal concentrations of CEA from moderate, intermediate and large elevations.
Evaluation and optimization of the Circulating Cathodic Antigen (POC-CCA) cassette test for detecting Schistosoma mansoni infection by using image analysis in school children in Mwanza Region, Tanzania.
Casacuberta, Miriam; Kinunghi, Safari; Vennervald, Birgitte J; Olsen, Annette
There is a need for diagnostic techniques which are sensitive, specific, rapid and easy to perform at the point-of-care. The aim of this study was to evaluate the diagnostic performance of the Circulating Cathodic Antigen (POC-CCA) assay for Schistosoma mansoni in four schools along the coast of Lake Victoria in Mwanza Region, Tanzania, and to optimize the reading of the POC-CCA test lines by using a computer software image analysis. Initially, a pilot study in 106 school children indicated that time of urine collection did not have an impact on CCA results as 84.9% (90) had identical scores from a urine collected in the morning and a urine taken at midday after drinking 0.5 L of water. The main study was conducted among 404 school children (aged 9-12 years) where stool and urine samples were collected for three consecutive days. For S. mansoni diagnosis, stool samples were examined for eggs with duplicate Kato-Katz smears, whereas urine samples were tested for presence of antigen by POC-CCA. The proportion of positive individuals for S. mansoni by one POC-CCA was higher compared to two Kato-Katz smears (66.1% vs. 28.7%; p < 0.0001). Both proportions increased expectedly when three POC-CCAs were compared to six Kato-Katz smears (75.0% vs. 42.6%; p < 0.0001). Three POC-CCAs were more sensitive (94.7%) than six Kato-Katz smears (53.8%) using the combined results of three POC-CCAs and six Kato-Katz smears as the 'gold standard'. To optimize the reading of the POC-CCA, a Software tool (Image Studio Lite®) was used to read and quantify the colour (expressed as pixels) of the test line on all positive tests, showing a positive correlation between number of pixels and the visually scored intensities and between number of pixels and egg counts. In conclusion, the POC-CCA assay seems to be a more appropriate tool for S. mansoni diagnosis compared to the Kato-Katz method in endemic communities such as Mwanza Region. Optimization of the tool in terms of cassette
DiMaio, Michael A; Sahoo, Malaya K; Waggoner, Jesse; Pinsky, Benjamin A
Influenza infections are associated with thousands of hospital admissions and deaths each year. Rapid detection of influenza is important for prompt initiation of antiviral therapy and appropriate patient triage. In this study the Cepheid Xpert Flu assay was compared with two rapid antigen tests, BinaxNOW Influenza A & B and BD Directigen EZ Flu A+B, as well as direct fluorescent antibody testing for the rapid detection of influenza A and B. Using real-time, hydrolysis probe-based, reverse transcriptase PCR as the reference method, influenza A sensitivity was 97.3% for Xpert Flu, 95.9% for direct fluorescent antibody testing, 62.2% for BinaxNOW, and 71.6% for BD Directigen. Influenza B sensitivity was 100% for Xpert Flu and direct fluorescent antibody testing, 54.5% for BinaxNOW, and 48.5% for BD Directigen. Specificity for influenza A was 100% for Xpert Flu, BinaxNOW, and BD Directigen, and 99.2% for direct fluorescent antibody testing. All methods demonstrated 100% specificity for influenza B. These findings support the use of the Xpert Flu assay in settings requiring urgent diagnosis of influenza A and B.
Mir, Fazia; Achakzai, Ilyas; Ibdah, Jamal A.
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. PMID:28255472
Mir, Fazia; Achakzai, Ilyas; Ibdah, Jamal A; Tahan, Veysel
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.
Cohen, J; Levy, C; Chalumeau, M; Bidet, Ph; Cohen, R
Group A streptococcus (GAS) is the most frequently identified bacterium in children with acute pharyngitis. Clinical signs and symptoms cannot distinguish accurately between viral and GAS pharyngitis. Rapid antigen detection tests (RADTs) can identify GAS by an immunologic reaction within a few minutes. Compared to throat culture, most RADTs have a high specificity (around 95 %), allowing antibiotic prescribing on the basis of a positive RADT result. Similarly, the negative predictive value of RADTs seems sufficiently high (around 95 %) to ensure against the presence of GAS in case of a negative RADT result. Among several factors affecting RADT sensitivity, the training and expertise of the person performing the test and the quality of the throat swab specimen seem to be key determinants. Available evidence suggests that clinical prediction rules for the triage of children who should undergo GAS testing are not sufficiently accurate. Implementing RADTs into clinical practice has an important impact on antibiotic prescription rates, for a reduction of about 30 %. French guidelines that recommend using RADTs in all children above 3 years of age presenting with pharyngitis without backup culture of negative tests seem relevant in this context.
Nakata, S; Chiba, S; Terashima, H; Sakuma, Y; Kogasaka, R; Nakao, T
A microtiter solid-phase radioimmunoassay (RIA) was developed for detection of human calicivirus in stool specimens. Seventy-eight stool specimens were tested by RIA. All 17 specimens positive for human calicivirus by electron microscopy (EM) were also positive by RIA. In addition, of 21 specimens obtained from an outbreak of caliciviral gastroenteritis, 11 were positive by RIA but negative by EM. Of 20 specimens positive for rotavirus by EM and 20 nondiarrheic specimens with no virus, 2 and 1, respectively, were positive by RIA but were subsequently shown to be falsely positive by a blocking test. There was no cross-reaction between human and feline caliciviruses. Thus, the test was more sensitive than EM and, with an appropriate blocking test, was specific for human calicivirus. It might be especially useful for screening large numbers of stool specimens. PMID:6833476
Helbig, Dorit; Wagner, Andreas; Glei, Michael; Basu, Samar; Schubert, Rainer; Jahreis, Gerhard
Berry seeds are a tocopherol-rich by-product of fruit processing without specific commercial value. In a human intervention study, the physiological impact of blackcurrant seed press residue (PR) was tested. Thirty-six women (aged 24 +/- 3 years; twenty non-smokers, sixteen smokers) consumed 250 g bread/d containing 8% PR for a period of 4 weeks (period 3). Comparatively, a control bread without PR (250 g/d) was tested (period 2) and baseline data were obtained (period 1). Blood, stool and 24 h urine were collected during a 5 d standardised diet within each period. Tocopherol and Fe intakes were calculated from food intake. In serum, tocopherol concentration and Fe parameters were determined. In urine, oxidative stress markers 8-oxo-2'-deoxyguanosine, 8-iso-PGF2alpha and inflammatory response marker 15-keto-dihydro-PGF2alpha were analysed. Stool tocopherol concentration, genotoxicity of faecal water (comet assay) and antioxidant capacity of stool (aromatic hydroxylation of salicylic acid) were determined. Fe and total tocopherol intake, total tocopherol concentrations in serum and stool, and genotoxicity of faecal water increased with PR bread consumption (P < 0.05). The antioxidant capacity of stool decreased between baseline and intervention, expressed by increased formation of 2,3- and 2,5-dihydroxybenzoic acid in vitro (P < 0.05). In smokers, 8-oxo-2'-deoxyguanosine increased with PR consumption (P < 0.05). Prostane concentrations were unaffected by PR bread consumption. In summary, the intake of bread containing blackcurrant PR for 4 weeks increased serum and stool total tocopherol concentrations. However, various biomarkers indicated increased oxidative stress, suggesting that consumption of ground berry seed may not be of advantage.
Pal, Subhamoy; Dauner, Allison L.; Mitra, Indrani; Forshey, Brett M.; Garcia, Paquita; Morrison, Amy C.; Halsey, Eric S.; Kochel, Tadeusz J.; Wu, Shuenn-Jue L.
Background Early diagnosis of dengue virus (DENV) infection can improve clinical outcomes by ensuring close follow-up, initiating appropriate supportive therapies and raising awareness to the potential of hemorrhage or shock. Non-structural glycoprotein-1 (NS1) has proven to be a useful biomarker for early diagnosis of dengue. A number of rapid diagnostic tests (RDTs) and enzyme-linked immunosorbent assays (ELISAs) targeting NS1 antigen (Ag) are now commercially available. Here we evaluated these tests using a well-characterized panel of clinical samples to determine their effectiveness for early diagnosis. Methodology/Principal Findings Retrospective samples from South America were used to evaluate the following tests: (i) “Dengue NS1 Ag STRIP” and (ii) “Platelia Dengue NS1 Ag ELISA” (Bio-Rad, France), (iii) “Dengue NS1 Detect Rapid Test (1st Generation)” and (iv) “DENV Detect NS1 ELISA” (InBios International, United States), (v) “Panbio Dengue Early Rapid (1st generation)” (vi) “Panbio Dengue Early ELISA (2nd generation)” and (vii) “SD Bioline Dengue NS1 Ag Rapid Test” (Alere, United States). Overall, the sensitivity of the RDTs ranged from 71.9%–79.1% while the sensitivity of the ELISAs varied between 85.6–95.9%, using virus isolation as the reference method. Most tests had lower sensitivity for DENV-4 relative to the other three serotypes, were less sensitive in detecting secondary infections, and appeared to be most sensitive on Day 3–4 post symptom onset. The specificity of all evaluated tests ranged from 95%–100%. Conclusions ELISAs had greater overall sensitivity than RDTs. In conjunction with other parameters, the performance data can help determine which dengue diagnostics should be used during the first few days of illness, when the patients are most likely to present to a clinic seeking care. PMID:25412170
Staib, F; Folkens, U; Tompak, B; Abel, T; Thiel, D
The strikingly frequent and constant presence of Aspergillus fimigatus in the soil of potted ornamental plants kept in private houses and hospitals has been the reason for studying the antigens of the strains found from the diagnostic and epidemiological angles. Culture-filtrate antigens of A. fumigatus strains isolated from the soil of 4 different ornamental plants, epiphyllum (Epiphyllum truncatum), orange tree (Citrus sinensis), Alpine rose (Azalea indica) and Christmas flower (Euphorbia pulcherrima), were compared, in the immunodiffusion test, with antigens of A. fumigatus strains from aspergillosis patients prepared in an identical way. When tested against 8 different sera from different aspergillosis patients there was a good coincidence of results. Control sera from patients suffering from diseases other than aspergillosis, no false-positive reactions could be observed. The findings are discussed in respect of diagnosis and epidemiology.
Schlenker, Nicklas; Bauer, Malkin; Helfrich, Kerstin; Mengele, Carolin; Löscher, Thomas; Nothdurft, Hans Dieter; Bretzel, Gisela; Beissner, Marcus
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.
Rivoire, Becky L.; TerLouw, Stephen; Groathouse, Nathan A.; Brennan, Patrick J.
True incidence of leprosy and its impact on transmission will not be understood until a tool is available to measure pre-symptomatic infection. Diagnosis of leprosy disease is currently based on clinical symptoms, which on average take 3–10 years to manifest. The fact that incidence, as defined by new case detection, equates with prevalence, i.e., registered cases, suggests that the cycle of transmission has not been fully intercepted by implementation of multiple drug therapy. This is supported by a high incidence of childhood leprosy. Epidemiological screening for pre-symptomatic leprosy in large endemic populations is required to facilitate targeted chemoprophylactic interventions. Such a test must be sensitive, specific, simple to administer, cost-effective, and easy to interpret. The intradermal skin test method that measures cell-mediated immunity was explored as the best option. Prior knowledge on skin testing of healthy subjects and leprosy patients with whole or partially fractionated Mycobacterium leprae bacilli, such as Lepromin or the Rees' or Convit' antigens, has established an acceptable safety and potency profile of these antigens. These data, along with immunoreactivity data, laid the foundation for two new leprosy skin test antigens, MLSA-LAM (M. leprae soluble antigen devoid of mycobacterial lipoglycans, primarily lipoarabinomannan) and MLCwA (M. leprae cell wall antigens). In the absence of commercial interest, the challenge was to develop these antigens under current good manufacturing practices in an acceptable local pilot facility and submit an Investigational New Drug to the Food and Drug Administration to allow a first-in-human phase I clinical trial. PMID:24874086
Bailey, James R; Aggarwal, Ashish; Imperiale, Thomas F
Colorectal cancer screening dates to the discovery of precancerous adenomatous tissue. Screening modalities and guidelines directed at prevention and early detection have evolved and resulted in a significant decrease in the prevalence and mortality of colorectal cancer via direct visualization or using specific markers. Despite continued efforts and an overall reduction in deaths attributed to colorectal cancer over the last 25 years, colorectal cancer remains one of the most common causes of malignancy-associated deaths. In attempt to further reduce the prevalence of colorectal cancer and associated deaths, continued improvement in screening quality and adherence remains key. Noninvasive screening modalities are actively being explored. Identification of specific genetic alterations in the adenoma-cancer sequence allow for the study and development of noninvasive screening modalities beyond guaiac-based fecal occult blood testing which target specific alterations or a panel of alterations. The stool DNA test is the first noninvasive screening tool that targets both human hemoglobin and specific genetic alterations. In this review we discuss stool DNA and other commercially available noninvasive colorectal cancer screening modalities in addition to other targets which previously have been or are currently under study.
Brennan, Denise E; Omorogbe, Joseph; Hussey, Mary; Tighe, Donal; Holleran, Grainne; O’Morain, Colm; Smith, Sinéad M; McNamara, Deirdre
AIM To compare (1) demographics in urea breath test (UBT) vs endoscopy patients; and (2) the molecular detection of antibiotic resistance in stool vs biopsy samples. METHODS Six hundred and sixteen adult patients undergoing endoscopy or a UBT were prospectively recruited to the study. The GenoType HelicoDR assay was used to detect Helicobacter pylori (H. pylori) and antibiotic resistance using biopsy and/or stool samples from CLO-positive endoscopy patients and stool samples from UBT-positive patients. RESULTS Infection rates were significantly higher in patients referred for a UBT than endoscopy (overall rates: 33% vs 19%; treatment-naïve patients: 33% vs 14.7%, respectively). H. pylori-infected UBT patients were younger than H. pylori-infected endoscopy patients (41.4 vs 48.4 years, respectively, P < 0.005), with a higher percentage of H. pylori-infected males in the endoscopy-compared to the UBT-cohort (52.6% vs 33.3%, P = 0.03). The GenoType HelicoDR assay was more accurate at detecting H. pylori infection using biopsy samples than stool samples [98.2% (n = 54/55) vs 80.3% (n =53/66), P < 0.005]. Subset analysis using stool and biopsy samples from CLO-positive endoscopy patients revealed a higher detection rate of resistance-associated mutations using stool samples compared to biopsies. The concordance rates between stool and biopsy samples for the detection of H. pylori DNA, clarithromycin and fluoroquinolone resistance were just 85%, 53% and 35%, respectively. CONCLUSION Differences between endoscopy and UBT patients provide a rationale for non-invasive detection of H. pylori antibiotic resistance. However, the GenoType HelicoDR assay is an unsuitable approach. PMID:27895408
Aslanzadeh, Jaber; Zheng, Xiaotian; Li, Haijing; Tetreault, Janice; Ratkiewicz, Irene; Meng, Shufang; Hamilton, Pamela; Tang, Yi-Wei
Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) are two important viral pathogens that cause respiratory tract infections in the pediatric population. The rapid detection of these agents allows the prompt isolation and treatment of infected patients. In the present prospective study, we evaluated the performances of four rapid antigen detection assays, including a rapid chromatographic immunoassay (CIA) for RSV (Directigen EZ RSV; Becton Dickinson, Sparks, MD), a direct fluorescent-antibody assay (DFA) for RSV (Bartels; Trinity Biotech, Carlsbad, CA), and two DFAs for hMPV manufactured by Diagnostic Hybrids Inc. (DHI; Athens, OH) and Imagen (Oxoid Ltd., Basingstoke, Hampshire, United Kingdom). The clinical specimens tested comprised 515 nasopharyngeal aspirates submitted to the Clinical Microbiology Laboratory at Hartford Hospital from 1 November 2006 to 21 April 2007. Compared to the results of real-time reverse transcription-PCR (RT-PCR), the CIA had a sensitivity of 79.8% and a specificity of 89.5%. The RSV DFA with Bartels reagents showed a sensitivity of 94.1% and a specificity of 96.8%. For hMPV, the sensitivity and specificity were 62.5% and 99.8%, respectively, for the DHI DFA and 63.2% and 100%, respectively, for the Imagen DFA. The hands-on and test turnaround times for CIA were 10 and 30 to 60 min, respectively, and the hands-on and test turnaround times for the RSV and hMPV DFAs were 30 and 105 min, respectively. We conclude that while the RSV CIA is user-friendly, it lacks sensitivity and specificity, especially during off-peak months. In contrast, the RSV DFA is more sensitive and specific, but interpretation of its results is subjective and it demands technical time and expertise. Similarly, both hMPV DFAs are highly specific in comparison to the results of RT-PCR, but their sensitivities await further improvements.
Aslanzadeh, Jaber; Zheng, Xiaotian; Li, Haijing; Tetreault, Janice; Ratkiewicz, Irene; Meng, Shufang; Hamilton, Pamela; Tang, Yi-Wei
Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) are two important viral pathogens that cause respiratory tract infections in the pediatric population. The rapid detection of these agents allows the prompt isolation and treatment of infected patients. In the present prospective study, we evaluated the performances of four rapid antigen detection assays, including a rapid chromatographic immunoassay (CIA) for RSV (Directigen EZ RSV; Becton Dickinson, Sparks, MD), a direct fluorescent-antibody assay (DFA) for RSV (Bartels; Trinity Biotech, Carlsbad, CA), and two DFAs for hMPV manufactured by Diagnostic Hybrids Inc. (DHI; Athens, OH) and Imagen (Oxoid Ltd., Basingstoke, Hampshire, United Kingdom). The clinical specimens tested comprised 515 nasopharyngeal aspirates submitted to the Clinical Microbiology Laboratory at Hartford Hospital from 1 November 2006 to 21 April 2007. Compared to the results of real-time reverse transcription-PCR (RT-PCR), the CIA had a sensitivity of 79.8% and a specificity of 89.5%. The RSV DFA with Bartels reagents showed a sensitivity of 94.1% and a specificity of 96.8%. For hMPV, the sensitivity and specificity were 62.5% and 99.8%, respectively, for the DHI DFA and 63.2% and 100%, respectively, for the Imagen DFA. The hands-on and test turnaround times for CIA were 10 and 30 to 60 min, respectively, and the hands-on and test turnaround times for the RSV and hMPV DFAs were 30 and 105 min, respectively. We conclude that while the RSV CIA is user-friendly, it lacks sensitivity and specificity, especially during off-peak months. In contrast, the RSV DFA is more sensitive and specific, but interpretation of its results is subjective and it demands technical time and expertise. Similarly, both hMPV DFAs are highly specific in comparison to the results of RT-PCR, but their sensitivities await further improvements. PMID:18337386
Okarma, T B; Krueger, J A; Holman, H R
Antibodies to different components of the extractable nuclear antigen (ENA) have been thought to be serological markers for clinical subsets of rheumatic diseases. However, incomplete characterization and standardization of antigenic components such as ribonucleoprotein (RNP), Sm, and SS-B (Ha), and the multiplicity of autoantibodies produced by different patients have confounded correlations between autoantibody specificity and disease subsets. This study describes the preparative separation of the antigens Sm, RNP, and Ss-B (Ha) by electrofocusing and their use in a rocket electrophoretic assay that in one step identifies and quantifies the multiple reactivities of patient sera exhibiting the speckled FANA pattern. Preparative electrofocusing generates milligram quantities of these antigens with retention of their immunologic and biochemical characteristics, facilitating further study of their biological properties and relationships to disease subsets.
Ahmed, Farid E; Vos, Paul; iJames, Stephanie; Lysle, Donald T; Allison, Ron R; Flake, Gordon; Sinar, Dennis R; Naziri, Wade; Marcuard, Stefan P; Pennington, Rodney
There is a need for sensitive and specific diagnostic molecular markers that can be used to monitor early patterns of gene expression in non-invasive exfoliated colonocytes shed in the stool, and in situ in adenoma-carcinoma epithelium of the colon. RNA-based detection methods are more comprehensive than either DNA-, protein- or methylation-based screening methods. By routinely and systematically being able to perform quantitative gene expression studies on these samples using less than ten colon cancer genes selected by the enormous resources of the National Cancer Institute's Cancer Genome Anatomy Project, we were able to monitor changes at various stages in the neoplastic process, allowing for reliable diagnostic screening of colon cancer particularly at the early, pre-malignant stages. Although the expression of some of the genes tested in tissue showed less variability in normal or cancerous patients than in stool, the stool by itself is suitable for screening. Thus, a transcriptomic approach using stool or tissue samples promises to offer more sensitivity and specificity than currently used molecular screening methods for colon cancer. A larger prospective clinical study utilizing stool and tissue samples derived from many control and colon cancer patients, to allow for a statistically valid analysis, is now urgently required to determine the true sensitivity and specificity of the transcriptomic screening approach for this preventable cancer.
Clostridium difficile is a major cause of nosocomial antibiotic-associated infectious diarrhea and pseudomembranous colitis. Detection of C. difficile by anaerobic bacterial culture and/or cytotoxicity assays has been largely replaced by rapid enzyme immunoassays (EIA). However, due to the lack of sensitivity of stool EIA, we developed a multiplex real-time PCR assay targeting the C. difficile toxin genes tcdB. stool samples from hospitalized pediatric patients suspected of having C. difficile-associated disease were prospectively collected. Three testing modalities were evaluated, including enriched culture, cepheid Xpert and real-time Pcr (tcdB) on stool samples performed with tcdB gene-specific primers and hydrolysis probes. A total of 150 de-identified clinical specimen were analyzed. The sensitivities of stool real-time Pcr were 95% against cepheid Xpert C. difficile and 93% against enriched culture respectively, with a specificity of 97% and 94%. The lower limit of detection of the stool real-time PCR was 0.5 cFU/ml of per reaction for tcdB. Direct detection of C. difficile toxin genes in stool samples by real-time Pcr showed performance comparable to enriched culture. Real-time PCR of DNA from stool samples is a rapid and cost-effective diagnostic modality for patients that should facilitate appropriate patient management.
Clostridium difficile is a major cause of nosocomial antibiotic-associated infectious diarrhea and pseudomembranous colitis. Detection of C. difficile by anaerobic bacterial culture and/or cytotoxicity assays has been largely replaced by rapid enzyme immunoassays (EIA). However, due to the lack of sensitivity of stool EIA, we developed a multiplex real-time PCR assay targeting the C. difficile toxin genes tcdB. stool samples from hospitalized pediatric patients suspected of having C. difficile-associated disease were prospectively collected. Three testing modalities were evaluated, including enriched culture, cepheid Xpert and real-time Pcr (tcdB) on stool samples performed with tcdB gene-specific primers and hydrolysis probes. A total of 150 de-identified clinical specimen were analyzed. The sensitivities of stool real-time Pcr were 95% against cepheid Xpert C. difficile and 93% against enriched culture respectively, with a specificity of 97% and 94%. The lower limit of detection of the stool real-time PCR was 0.5 cFU/ml of per reaction for tcdB. Direct detection of C. difficile toxin genes in stool samples by real-time Pcr showed performance comparable to enriched culture. Real-time PCR of DNA from stool samples is a rapid and cost-effective diagnostic modality for patients that should facilitate appropriate patient management. PMID:27829823
Zimmer, B L; Pappagianis, D
The antigen participating in the tube precipitin (TP) serologic test for coccidioidomycosis was isolated from mycelial-phase antigen (coccidioidin) by immunoaffinity and characterized by various analytical procedures. This was accomplished by first preparing the antigen-antibody precipitate by using antigen and human serum positive for TP (immunoglobulin M) antibody and then liberating the antigen by digestion with pronase. This protease destroyed the antibody and left the antigen intact as indicated by immunodiffusion-TP. The coccidioidal antigen was isolated from the proteolytic digest by using size exclusion chromatography. DEAE chromatography of this antigen yielded two fractions with immunodiffusion-TP reactivity which had average molecular sizes of 225 and 140 kilodaltons, respectively. The presence of carbohydrate and amino acids indicated that the antigen(s) is a glycopeptide. Compositional analysis showed that one fraction contained 3-O-methylmannose, mannose, and glucose in a ratio of 8:1.2:1, whereas the second fraction contained 3-O-methylmannose, mannose, glucose, and galactose in a ratio of 1:1:1:1. The amino acids glycine, alanine, serine, threonine, aspartic acid plus asparagine, and glutamic acid plus glutamine constituted 60 to 70% of the amino acids in both glycopeptides. Neither antigen could be detected entering the gel in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Lectin affinity provided evidence of a high-mannose asparagine-linked glycopeptide in the first peak and an asparagine-linked glycopeptide with a biantennary complex-type structure in the second peak. Images PMID:2504775
Chen, Shuxiong; Parlane, Natalie A; Lee, Jason; Wedlock, D Neil; Buddle, Bryce M; Rehm, Bernd H A
The tuberculin skin test for diagnosing tuberculosis (TB) in cattle lacks specificity if animals are sensitized to environmental mycobacteria, as some antigens in purified protein derivative (PPD) prepared from Mycobacterium bovis are present in nonpathogenic mycobacteria. Three immunodominant TB antigens, ESAT6, CFP10, and Rv3615c, are present in members of the pathogenic Mycobacterium tuberculosis complex but absent from the majority of environmental mycobacteria. These TB antigens have the potential to enhance skin test specificity. To increase their immunogenicity, these antigens were displayed on polyester beads by translationally fusing them to a polyhydroxyalkanoate (PHA) synthase which mediated formation of antigen-displaying inclusions in recombinant Escherichia coli. The most common form of these inclusions is poly(3-hydroxybutyric acid) (PHB). The respective fusion proteins displayed on these PHB inclusions (beads) were identified using tryptic peptide fingerprinting analysis in combination with matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). The surface exposure and accessibility of antigens were assessed by enzyme-linked immunosorbent assay (ELISA). Polyester beads displaying all three TB antigens showed greater reactivity with TB antigen-specific antibody than did beads displaying only one TB antigen. This was neither due to cross-reactivity of antibodies with the other two antigens nor due to differences in protein expression levels between beads displaying single or three TB antigens. The triple-antigen-displaying polyester beads were used for skin testing of cattle and detected all cattle experimentally infected with M. bovis with no false-positive reactions observed in those sensitized to environmental mycobacteria. The results suggested applicability of TB antigen-displaying polyester inclusions as diagnostic reagents for distinguishing TB-infected from noninfected animals.
Foster, Monique A.; Iqbal, Junaid; Zhang, Chengxian; McHenry, Rendie; Cleveland, Brent E.; Romero-Herazo, Yesenia; Fonnesbeck, Chris; Payne, Daniel C.; Chappell, James D.; Halasa, Natasha; Gómez-Duarte, Oscar G.
This prospective acute gastroenteritis (AGE) surveillance was conducted in the inpatient and emergency room settings at a referral pediatric hospital to determine the prevalence of diarrheagenic Escherichia coli (DEC) in children<12 years of age with AGE in Davidson County, Tennessee. Subjects 15 days to 11 years of age, who presented with diarrhea and/or vomiting, were enrolled. Stool specimens were processed for detection of DEC using multiplex polymerase chain reaction. From December 1, 2011, to June 30, 2012, a total of 79 (38%) out of 206 stool specimens from children with AGE tested positive for E. coli. A total of 12 (5.8%) out of 206 stool specimens from children with AGE were positive for a DEC. Eight (67%) out of these 12 were positive for enteropathogenic E. coli, and the remaining 4 were positive for enteroaggregative E. coli. DEC clinical isolates clustered with known E. coli enteropathogens according to multilocus sequencing typing. PMID:26298817
Foster, Monique A; Iqbal, Junaid; Zhang, Chengxian; McHenry, Rendie; Cleveland, Brent E; Romero-Herazo, Yesenia; Fonnesbeck, Chris; Payne, Daniel C; Chappell, James D; Halasa, Natasha; Gómez-Duarte, Oscar G
This prospective acute gastroenteritis (AGE) surveillance was conducted in the inpatient and emergency room settings at a referral pediatric hospital to determine the prevalence of diarrheagenic Escherichia coli (DEC) in children <12years of age with AGE in Davidson County, Tennessee. Subjects 15 days to 11 years of age, who presented with diarrhea and/or vomiting, were enrolled. Stool specimens were processed for detection of DEC using multiplex polymerase chain reaction. From December 1, 2011, to June 30, 2012, a total of 79 (38%) out of 206 stool specimens from children with AGE tested positive for E. coli. A total of 12 (5.8%) out of 206 stool specimens from children with AGE were positive for a DEC. Eight (67%) out of these 12 were positive for enteropathogenic E. coli, and the remaining 4 were positive for enteroaggregative E. coli. DEC clinical isolates clustered with known E. coli enteropathogens according to multilocus sequencing typing.
Turner, Barbara J; Mavandadi, Shahrzad; Weiner, Mark G
Delayed evaluation after a clearly abnormal prostate-specific antigen (PSA) result may contribute to more advanced prostate cancer at diagnosis in black men. In 46 primary care practices over a period of 4.5 years, we studied men aged more than 50 years without known prostate cancer who had a PSA of at least 10.0 ng/mL for the first time. PSA follow-up included: a urology appointment, a new prostate diagnosis, or repeat PSA test. Cox proportional hazards models assessed time to follow-up, adjusting for demographic, clinical, and health care factors with censoring at a time that represents excessive delay (200 days). Among all 724 study men (27% black), delay until PSA follow-up averaged 115.2 days (+/- 79.7 d) and the unadjusted hazard ratio (HR) for follow-up was shorter for black men than nonblack men (HR, 1.23; 95% CI, 1.00-1.51). However, black men were more likely to have had prior urology care and had higher index PSA levels than other men; both factors were associated with shorter follow-up. After adjustment, delay did not differ for black vs nonblack race (HR, 1.05; 95% Cl, 0.78-1.43) but men aged at least 75 years had a longer delay than men aged 74 years or less (HR, 0.72; 95% CI, 0.59-0.89). Despite black men having greater risk of advanced prostate disease at diagnosis and better linkage to urologic care, follow-up was delayed, on average, by more than 3 months and did not differ by race. These results reveal a potentially important, remediable factor to improve prostate cancer prevention and care for black men.
Gao, Chun-hua; Yang, Yue-tao; Shi, Feng; Wang, Jun-yun; Steverding, Dietmar; Wang, Xia
Background Visceral leishmaniasis (VL) is a life-threatening disease caused by protozoan parasites of the Leishmania donovani complex. Early case detection followed by adequate treatment is essential to the control of VL. However, the available diagnostic tests are either invasive and require considerable expertise (parasitological demonstration of the parasite in tissue smears) or unable to distinguish between past and active infection (serological methods). Therefore, we aimed to develop a lateral flow assay in the form of an immunochromatographic test (ICT) device based on the detection of a circulating Leishmania antigen using monoclonal antibodies (mAbs). Methodology/Principal Findings mAbs were produced by fusion of murine myeloma cells with splenocytes isolated from a mouse immunized with L. donovani soluble crude antigen. Out of 12 cloned hybridoma cell lines, two secreted mAbs recognizing the same leishmanial protein. These mAbs were used to produce an ICT as a sandwich assay for the detection of circulating antigen in serum and blood samples. The ICT was evaluated with 213 serum samples from VL patients living in VL endemic areas in China, and with 156 serum samples from patients with other diseases as well as 78 serum samples from healthy donors. Sensitivity, specificity and diagnostic efficiency of the new ICT was 95.8%, 98.7% and 97.3%, respectively. Compared with a commercially available antibody detecting ICT, our antigen-based ICT performed slightly better. Conclusion/Significance The newly developed ICT is an easy to use and more accurate diagnostic tool which fulfils the performance and operational characteristics required for VL case detection under field and laboratory conditions. As our ICT detects a circulating antigen, it will also be useful in monitoring treatment success and diagnosing VL in immunocompromised patients. PMID:26125560
Bond, Ross; Hutchinson, Melanie J; Loeffler, Anette
The results of intradermal testing with three commercial flea antigens and a serological test for IgE antibodies to flea antigens were compared with live flea challenge in cats. Eight control cats with no prior flea exposure had negative serological test and flea challenge results. By contrast, 17 out of 27 cats with previous flea exposure showed immediate reactivity to flea challenge; reactivity at 6, 24 and 48 h after flea exposure was noted in 12, 16 and 21 cats, respectively. Seventeen of these cats had positive serological test results. Seven cats showed immediate intradermal test reactions to the ARTU allergen, six reacted to the Biophady allergen, and six reacted to the Greer allergen. Intradermal test reactivity was less frequent at the other time points. Using the results of the flea challenge as the 'gold standard' for the presence or absence of sensitisation to fleas, the sensitivity and specificity of the serological test was 0.88 and 0.77, respectively. Sensitivities of the intradermal tests at the four time points ranged from 0 to 0.33, whereas the specificities ranged from 0.78 to 1.0. Live flea challenge is better able to detect cats with hypersensitivity to fleas than either intradermal or serological testing.
Boutton, T W; Hopkinson, J M; Benton, D A; Klein, P D
Studies of the absorption and bioavailability of nutrients naturally enriched with 13C require accurate measurements of small increases of 13C in respiratory CO2 and stool carbon. The sensitivity of these measurements would be increased if the natural background of 13C in these excreta were reduced. We have developed a 13C-depleted infant formula based on lactose, whey, and casein from New Zealand cows that consume only C3 vegetation naturally low in 13C. This formula, designated CNRC3, was produced by a commercial infant formula manufacturer and was comparable with a 60:40 whey/casein product. To test the ability of the formula to reduce baseline levels of 13C in infant excreta, 10 formula-fed infants 28-60 days old and free of metabolic disorders were enrolled in the 9-day study. Two stool samples were collected daily. Infants received their usual formula on days 1 and 2 and were switched to CNRC3 formula for days 3-9. On days 2 and 9, seven breath samples were collected at 30-min intervals with a face mask. Breath and stool samples were analyzed for 13C content by gas isotope ratio mass spectrometry. Infants consuming their commercial formula had breath delta 13C values of -21.1 +/- 0.6% over the 3-h collection period; stool values were -22.9 +/- 0.4%. After 7 days on the CNRC3 formula, delta 13C values of breath declined by 5.6% to -26.7 +/- 0.7%; stool values declined by 3.0% to -25.6 +/- 0.5%. The reduced background of 13C achieved by the CNRC3 formula can improve resolution of excess 13C from naturally enriched substrates in infant breath by approximately 50% and in stool by approximately 30%.
Phillips, A P; Martin, K L
Fluorescein-conjugated rabbit antibodies to formalized spores of Bacillus anthracis were tested against strains of B. anthracis and other Bacillus species in a subjective immunofluorescence test. The lack of reaction of B. anthracis Vollum spores with conjugated antibody raised against B. anthracis Sterne spores indicated that spores of the Vollum strain lacked a major surface antigen present in most of the other anthrax strains tested, including the non-encapsulated strains Sterne and the Soviet ST1, variants cured of the pX01 plasmid that codes for the toxin, and several virulent strains. Four other antibody preparations, raised against B. anthracis Vollum, New Hampshire, Ames and Strain 15, reacted to an approximately similar degree with spores of all four strains and of Sterne, indicating that Vollum has at least one spore antigen in common with these other strains. The anti-Sterne and anti-Vollum conjugates both displayed cross-reactions with spores of strains of B. cereus, B. coagulans, B. subtilis, B. megaterium, B. polymyxa, B. pumilus and B. thuringiensis. Absorption of the anti-anthrax conjugates with B. cereus NCTC 8035 and NCTC 10320 removed all these cross-reactions, demonstrating the existence of spore antigens specific for anthrax.
Westman, Mark E; Malik, Richard; Hall, Evelyn; Sheehy, Paul A; Norris, Jacqueline M
Feline leukaemia virus (FeLV) can be a challenging infection to diagnose due to a complex feline host-pathogen relationship and occasionally unreliable test results. This study compared the accuracy of three point-of-care (PoC) FeLV p27 antigen test kits commonly used in Australia and available commercially worldwide (SNAP FIV/FeLV Combo, Witness FeLV/FIV and Anigen Rapid FIV/FeLV), using detection of FeLV provirus by an in-house real-time polymerase chain reaction (qPCR) assay as the diagnostic gold standard. Blood (n=563) and saliva (n=419) specimens were collected from a population of cats determined to include 491 FeLV-uninfected and 72 FeLV-infected individuals (45 progressive infections [p27 and qPCR positive], 27 regressive infections [p27 negative, qPCR positive]). Sensitivity and specificity using whole blood was 63% and 94% for SNAP Combo, 57% and 98% for Witness, and 57% and 98% for Anigen Rapid, respectively. SNAP Combo had a significantly lower specificity using blood compared to the other two kits (P=0.004 compared to Witness, P=0.007 compared to Anigen Rapid). False-positive test results occurred with all three kits using blood, and although using any two kits in parallel increased specificity, no combination of kits completely eliminated the occurrence of false-positive results. We therefore recommend FeLV proviral PCR testing for any cat that tests positive with a PoC FeLV antigen kit, as well as for any cat that has been potentially exposed to FeLV but tests negative with a FeLV antigen kit, before final assignment of FeLV status can be made with confidence. For saliva testing, sensitivity and specificity was 54% and 100%, respectively, for all three test kits. The reduced sensitivity of saliva testing compared to blood testing, although not statistically significant, suggests saliva testing with the current generation of PoC FeLV antigen kits is unsuitable for screening large populations of cats, such as in shelters.
Rooney, Barrie; Piening, Turid; Büscher, Philippe; Rogé, Stijn; Smales, C. Mark
The development of rapid serodiagnostic tests for sleeping sickness and other diseases caused by kinetoplastids relies on the affordable production of parasite-specific recombinant antigens. Here, we describe the production of recombinant antigens from Trypanosoma brucei gambiense (T.b. gambiense) in the related species Leishmania tarentolae (L. tarentolae), and compare their diagnostic sensitivity and specificity to native antigens currently used in diagnostic kits against a panel of human sera. A number of T.b. gambiense protein antigen candidates were chosen for recombinant expression in L. tarentolae based on current diagnostics in field use and recent findings on immunodiagnostic antigens found by proteomic profiling. In particular, the extracellular domains of invariant surface glycoprotein 65 (ISG65), variant surface glycoproteins VSG LiTat 1.3 and VSG LiTat 1.5 were fused with C-terminal histidine tags and expressed as soluble proteins in the medium of cultured, recombinant L. tarentolae. Using affinity chromatography, on average 10 mg/L of recombinant protein was purified from cultures and subsequently tested against a panel of sera from sleeping sickness patients from controls, i.e. persons without sleeping sickness living in HAT endemic countries. The evaluation on sera from 172 T.b. gambiense human African trypanosomiasis (HAT) patients and from 119 controls showed very high diagnostic potential of the two recombinant VSG and the rISG65 fragments with areas under the curve between 0.97 and 0.98 compared to 0.98 and 0.99 with native VSG LiTat 1.3 and VSG LiTat 1.5 (statistically not different). Evaluation on sera from 78 T.b. rhodesiense HAT patients and from 100 controls showed an acceptable diagnostic potential of rISG65 with an area under the curve of 0.83. These results indicate that a combination of these recombinant antigens has the potential to be used in next generation rapid serodiagnostic tests. In addition, the L. tarentolae expression system
Dunn, James J; Ginocchio, Christine C
Five years ago, the Point-Counterpoint series was launched. The initial article asked about the role of rapid immunochromatographic antigen testing in the diagnosis of influenza A virus 2009 H1N1 infection (D. F. Welch and C. C. Ginocchio, J Clin Microbiol 48:22-25, 2010, http://dx.doi.org/10.1128/JCM.02268-09). Since that article, not only have major changes been made in immunochromatographic antigen detection (IAD) testing for the influenza viruses, but there has also been rapid development of commercially available nucleic acid amplification tests (NAATs) for influenza virus detection. Further, a novel variant of influenza A, H7N9, has emerged in Asia, and H5N1 is also reemergent. In that initial article, the editor of this series, Peter Gilligan, identified two issues that required further consideration. One was how well IAD tests worked in clinical settings, especially in times of antigen drift and shift. The other was the role of future iterations of influenza NAATs and whether this testing would be available in a community hospital setting. James Dunn, who is Director of Medical Microbiology and Virology at Texas Children's Hospital, has extensive experience using IAD tests for diagnosing influenza. He will discuss the application and value of these tests in influenza diagnosis. Christine Ginocchio, who recently retired as the Senior Medical Director, Division of Infectious Disease Diagnostics, North Shore-LIJ Health System, and now is Vice President for Global Microbiology Affairs at bioMérieux, Durham, NC, wrote the initial counterpoint in this series, where she advocated the use of NAATs for influenza diagnosis. She will update us on the commercially available NAAT systems and explain what their role should be in the diagnosis of influenza infection.
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...
Minton, Jonathan; Boamah, Daniel; Otchere, Joseph; Asmah, Richard H; Rodgers, Mark; Bosompem, Kwabena M; Eusebi, Paolo; De Vlas, Sake J
Abstract Objective To assess the accuracy of point-of-care testing for circulatory cathodic antigen in the diagnosis of schistosome infection. Methods We searched MEDLINE, EMBASE, LILACS and other bibliographic databases for studies published until 30 September 2015 that described circulatory cathodic antigen testing compared against one to three Kato–Katz tests per subject – for Schistosoma mansoni – or the filtration of one 10-ml urine sample per subject – for S. haematobium. We extracted the numbers of true positives, false positives, true negatives and false negatives for the antigen testing and performed meta-analyses using a bivariate hierarchical regression model. Findings Twenty-six studies published between 1994 and 2014 met the inclusion criteria. In the detection of S. mansoni, a single antigen test gave a pooled sensitivity of 0.90 (95% confidence interval, CI: 0.84–0.94) and a pooled specificity of 0.56 (95% CI: 0.39–0.71; n = 7) when compared against a single Kato–Katz test. The corresponding values from comparisons with two to three Kato–Katz tests per subject were 0.85 (95% CI: 0.80–0.88) and 0.66 (95% CI: 0.53–0.76; n = 14), respectively. There appeared to be no advantage in using three antigen tests per subject instead of one. When compared against the results of urine filtration, antigen testing for S. haematobium showed poor sensitivity and poor specificity. The performance of antigen testing was better in areas of high endemicity than in settings with low endemicity. Conclusion Antigen testing may represent an effective tool for monitoring programmes for the control of S. mansoni. PMID:27429491
Greenberg, D N; Ascher, D P; Yoder, B A; Hensley, D M; Heiman, H S; Keith, J F
Latex particle agglutination (LPA) testing for antigen to group B streptococcus (GBS) has been useful in the diagnosis of GBS sepsis in newborns. However, recent reports have demonstrated that the sensitivity of LPA assays may be as low as 27 to 54%. The purposes of the present study were to directly compare the abilities of four urine antigen assays to detect GBS antigen with clinical urine samples from neonates with GBS bacteremia and to evaluate the effect of the urine concentration on the sensitivities and specificities of these assays. Urine samples were collected serially from neonates with blood cultures positive for GBS or on admission from healthy full-term infants. One milliliter of urine was removed, and the remainder was concentrated to a volume of 1 ml. Unconcentrated samples were serially diluted with normal saline and were assayed to determine the highest dilution which would produce a positive test result. The Wellcogen, Bactigen, and Directigen LPA tests and ICON immunoassay were directly compared by using concentrated and unconcentrated urine specimens and urine specimens with known titers. A total of 94 urine specimens, including 61 concentrated and 75 unconcentrated specimens, from bacteremic infants were available for sensitivity testing, and 220 urine specimens from uninfected infants were available for specificity testing. There were significant differences in sensitivity among the four assays when they were performed on concentrated urine specimens, as follows: Directigen, 98%; Bactigen, 92%; ICON, 89%; Wellcogen, 68%. When the assays were performed on unconcentrated urine specimens, the Directigen (84%) and Bactigen (76%) assays were each significantly more sensitive than the ICON (59%) or Wellcogen (43%) assay.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7699040
Nasci, Roger S; Gottfried, Kristy L; Burkhalter, Kristen L; Ryan, Jeffrey R; Emmerich, Eva; Davé, Kirti
VecTest assays for detecting eastern equine encephalitis virus (EEE) and western equine encephalitis virus (WEE) antigen in mosquito pools were evaluated to determine their sensitivity and specificity by using a range of EEE, WEE, St. Louis encephalitis virus (SLE), and West Nile virus (WN) dilutions as well as individual and pooled mosquitoes containing EEE or WEE. The EEE test produced reliable positive results with samples containing > or = 5.3 log10 plaque-forming units (PFU) of EEE/ml, and the WEE test produced reliable positive results with samples containing > or = 4.7 log10 PFU WEE/ml. Both assays detected the respective viral antigens in single virus-positive mosquitoes and in pools containing a single positive mosquito and 49 negative specimens. The SLE and WN assays also contained on the dipsticks accurately detected their respective viruses. No evidence was found of cross reaction or false positives in any of the tests. The VecTest assays were less sensitive than the EEE- and WEE-specific TaqMan reverse transcriptase polymerase chain reaction and Vero cell plaque assay, but appear to be useful for detecting arboviruses in mosquito-based arbovirus surveillance programs.
Schriefer, Albert; Magalhães, Andréa; Meyer, Roberto; Glesby, Marshall J.; Carvalho, Edgar M.; Carvalho, Lucas P.
Diagnosis of cutaneous leishmaniasis (CL) relies on clinical presentation, parasite isolation, histopathologic evaluation and positive Montenegro skin test. However, the low amounts of parasites in the lesion of these individuals make parasite isolation and histopatologic diagnosis unreliable, often leading to false-negative results. Also, 15% of people living in endemic areas have sub-clinical infection characterized by positive Montenegro skin test, which may contribute to misdiagnosis. Although the main Leishmania killing mechanism is through cell-mediated immune response, antibodies against Leishmania antigens are found in infected individuals. Here our goal was to develop a new serological technique using polystyrene microspheres sensitized with soluble Leishmania antigens as a tool for the detection of IgG in serum from CL patients by flow cytometry. To validate the assay we carried out a comparative test (ELISA) commonly used as a diagnostic test for parasitic diseases. To determine cross-reactivity we used serum from patients with Chagas disease, caused by a trypanosome that has several proteins with high homology to those of the Leishmania genus. We observed that the flow cytometry technique was more sensitive than the ELISA, but, less specific. Our results show that the flow cytometry serologic test can be used to confirm CL cases in L. braziliensis transmission areas, however, presence of Chagas disease has to be ruled out in these individuals. PMID:27622535
Harris, Aaron M; Beekmann, Susan E; Polgreen, Philip M; Moore, Matthew R
Streptococcus pneumoniae (pneumococcus) is the most common bacterial etiology of community-acquired pneumonia (CAP) in adults, a leading cause of death. The majority of pneumococcal CAP is diagnosed by blood culture, which likely underestimates the burden of disease. The 2007 CAP guidelines recommend routine use of the rapid pneumococcal urinary antigen (UAg) test. To assess the how pneumococcal UAg testing is being used among hospitalized adult CAP patients and what barriers restrict its use, a Web-based survey was distributed in 2013 to 1287 infectious disease physician members of the Emerging Infectious disease Network of the Infectious Disease Society of America. Of 493 eligible responses, 65% use the pneumococcal UAg test. The primary barrier to UAg use was availability (46%). UAg users reported ordering fewer other diagnostic tests and tailoring antibiotic therapy. Increased access to UAg tests could improve pneumonia management and pneumococcal CAP surveillance.
Ross, Louie E; Meade, Shelly-Ann; Powe, Barbara D; Howard, Daniel L
African-American men experience greater incidence and mortality from prostate cancer compared to White men as well as men from other groups. Few studies have examined prostate-specific antigen (PSA) test and digital rectal examination (DRE) use in African-American men. This study examined use of the PSA test and DRE among African-American men over time and identified correlates associated with the use of these procedures. Overall trends for years 2002-2006 showed a significant decrease in recent PSA test use and DRE among African-American men in 2004 and 2006 compared to year 2002. Recent PSA test use and DRE were associated with several factors including older ages, being married, higher levels of education and income, and overweight and obese body mass index (BMI). PSA test use and DRE among African-American men should be monitored over time to find out if this pattern continues.
Im, Justin; Nichols, Chelsea; Bjerregaard-Andersen, Morten; Sow, Amy Gassama; Løfberg, Sandra; Tall, Adama; Pak, Gi Deok; Aaby, Peter; Baker, Stephen; Clemens, John D.; Espinoza, Ligia Maria Cruz; Konings, Frank; May, Jürgen; Monteiro, Mario; Niang, Aissatou; Panzner, Ursula; Park, Se Eun; Schütt-Gerowitt, Heidi; Wierzba, Thomas F.; Marks, Florian; von Kalckreuth, Vera
Background. Chronic and convalescent carriers play an important role in the transmission and endemicity of many communicable diseases. A high incidence of Salmonella enterica serovar Typhi and invasive nontyphoidal Salmonella (NTS) infection has been reported in parts of sub-Saharan Africa, yet the prevalence of Salmonella excretion in the general population is unknown. Methods. Stool specimens were collected from a random sample of households in 2 populations in West Africa: Bissau, Guinea-Bissau, and Dakar, Senegal. Stool was cultured to detect presence of Salmonella, and antimicrobial susceptibility testing was performed on the isolated organisms. Results. Stool was cultured from 1077 and 1359 individuals from Guinea-Bissau and Senegal, respectively. Salmonella Typhi was not isolated from stool samples at either site. Prevalence of NTS in stool samples was 24.1 (95% confidence interval [CI], 16.5–35.1; n = 26/1077) per 1000 population in Guinea-Bissau and 10.3 (95% CI, 6.1–17.2; n = 14/1359) per 1000 population in Senegal. Conclusions. Evidence of NTS excretion in stool in both study populations indicates a possible NTS transmission route in these settings. PMID:26933022
Varela, P; Pollevick, G D; Rivas, M; Chinen, I; Binsztein, N; Frasch, A C; Ugalde, R A
A direct method to detect Vibrio cholerae in stool samples was developed by using a PCR procedure that did not require a DNA purification step. Dilution (1/100) of stool samples prevented inhibition of the reaction by contaminants, and two consecutive PCRs, the second one with a nested primer, achieved the desired sensitivity. Comparison of the results obtained from stool swab samples processed by the two-step PCR and by an enzyme-linked immunosorbent assay using GM1 as the capture molecule showed that the former is more sensitive and gave positive results even when V. cholerae was not culturable or dead. Images PMID:8051251
Yamaoka, Yutaro; Matsuyama, Shutoku; Fukushi, Shuetsu; Matsunaga, Satoko; Matsushima, Yuki; Kuroyama, Hiroyuki; Kimura, Hirokazu; Takeda, Makoto; Chimuro, Tomoyuki; Ryo, Akihide
Protein nativity is one of the most critical factors for the quality of antigens used as immunogens and the reactivities of the resultant antibodies. The preparation and purification of native viral antigens in conventional cell-based protein expression systems are often accompanied by technical hardships. These challenges are attributable mainly to protein aggregation and insolubility during expression and purification, as well as to very low expression levels associated with the toxicity of some viral proteins. Here, we describe a novel approach for the production of monoclonal antibodies (mAbs) against nucleocapsid protein (NP) of the Middle East respiratory syndrome coronavirus (MERS-CoV). Using a wheat germ cell-free protein synthesis system, we successfully prepared large amounts of MERS-CoV NP antigen in a state that was highly soluble and intact for immunization. Following mouse immunization and hybridoma generation, we selected seven hybridoma clones that produced mAbs with exclusive reactivity against MERS-CoV NP. Epitope mapping and subsequent bioinformatic analysis revealed that these mAbs recognized epitopes located within relatively highly conserved regions of the MERS-CoV amino-acid sequence. Consistently, the mAbs exhibited no obvious cross-reactivity with NPs derived from other related viruses, including SARS coronavirus. After determining the optimal combinations of these mAbs, we developed an enzyme-linked immunosorbent assay and a rapid immunochromatographic antigen detection test that can be reliably used for laboratory diagnosis of MERS-CoV. Thus, this study provides strong evidence that the wheat germ cell-free system is useful for the production of diagnostic mAbs against emerging pathogens. PMID:27148198
Nguyen, Thu-Thuy; Ruttayaporn, Ngasaman; Goto, Yasuyuki; Kawazu, Shin-ichiro; Sakurai, Tatsuya; Inoue, Noboru
Animal trypanosomosis is a disease that is distributed worldwide which results in huge economic losses due to reduced animal productivity. Endemic regions are often located in the countryside where laboratory diagnosis is costly or inaccessible. The establishment of simple, effective, and accurate field tests is therefore of great interest to the farming and veterinary sectors. Our study aimed to develop a simple, rapid, and sensitive immunochromatographic test (ICT) for animal trypanosomosis utilizing the recombinant tandem repeat antigen TeGM6-4r, which is conserved amongst salivarian trypanosome species. In the specificity analysis, TeGM6-4r/ICT detected all of Trypanosoma evansi-positive controls from experimentally infected water buffaloes. As expected, uninfected controls tested negative. All sera samples collected from Tanzanian and Ugandan cattle that were Trypanosoma congolense- and/or Trypanosoma vivax-positive by microscopic examination of the buffy coat were found to be positive by the newly developed TeGM6-4r/ICT, which was comparable to results from TeGM6-4r/ELISA (kappa coefficient [κ] = 0.78). TeGM6/ICT also showed substantial agreement with ELISA using Trypanosoma brucei brucei (κ = 0.64) and T. congolense (κ = 0.72) crude antigen, suggesting the high potential of TeGM6-4r/ICT as a field diagnostic test, both for research purposes and on-site diagnosis of animal trypanosomosis.
Okuno, Y; Takao, Y; Miyazaki, Y; Ohnishi, F; Okeda, M; Yano, S; Kumihashi, H; Gomi, Y; Maeda, K; Ishikawa, T; Mori, Y; Asada, H; Iso, H; Yamanishi, K
The Shozu Herpes Zoster (SHEZ) Study was designed to clarify the incidence of and predictive and immunological factors for herpes zoster in a defined community-based Japanese population. As part of this series, a total of 5683 residents aged ≥50 years received a varicella-zoster virus (VZV) skin test with VZV antigen, and 48 h later, the erythema and oedema were assessed by measuring the longest diameter. The diameters of both the erythema and oedema decreased with the increasing age of the subject. Sixty-three subjects contracted herpes zoster within a year after receiving the VZV skin test. Analysis of the herpes zoster incidence rate vs. the skin test reaction revealed that the shorter the diameter of erythema or oedema, the greater the likelihood of herpes zoster. These results demonstrated that the VZV skin test is an excellent surrogate marker for predicting the risk of herpes zoster.
Lancefield, Rebecca C.
In further study of streptococci having the R antigen, the bactericidal test has been used instead of the mouse protection test in investigating the type-specific M antigens of these organisms. The results have been confirmed by M anti-M precipitin tests, and a correlation between the M and T antigens of the strains has been shown. On the basis of a specific M antigen, type 28 has been shown to comprise Griffith's strain Small and four other R-containing strains. A number of other strains previously thought to belong to type 28 on the basis of R antigen reactions have now been identified as belonging either to type 2 or to a new type, designated 48, which shows a one-way cross-relationship to type 13. The bactericidal test is suggested as a useful method for assessing M antigen in group A streptococci and for establishing type-specificity by means of a biological test which is more widely applicable than the standard mouse protection test. PMID:13475611
Espino, A M; Finlay, C M
A sandwich enzyme-linked immunosorbent assay has been developed for the detection of Fasciola hepatica excretory secretory (ES) antigens in stool specimens of infected humans. The assay uses antibodies against F. hepatica ES antigens. A monoclonal antibody (ES78, mouse immunoglobulin G2a) was used to capture ES antigens, and a rabbit polyclonal antibody, peroxidase conjugate, was used to identify ES antigens. Thirteen of 14 patients with parasitological evidence of fascioliasis had a detectable concentration of ES antigens (more than 15 ng/ml). None of the stool specimens from controls and from patients with parasites other than F. hepatica showed a positive reaction, suggesting the absence of cross-reactions in this assay. When the 14 patients were retested 2 months after treatment, all of the specimens from the 11 parasitologically cured patients were negative by the antigen detection assay while the specimens from the 3 patients with persisting F. hepatica eggs in their stools remained positive. PMID:8126178
Blum, R N; Berry, C D; Phillips, M G; Hamilos, D L; Koneman, E W
The clinical significance of the fastidious organism DF-3 isolated from stool cultures is unclear. We sought to improve our understanding of this organism and to further define its association with human disease. Stool cultures for DF-3 were obtained from three sources: an ongoing study of enteric pathogens in patients infected with the human immunodeficiency virus, a screening procedure in which all stool samples submitted for Clostridium difficile toxin assay were cultured for DF-3, and stool samples submitted specifically for DF-3 culture. Retrospective clinical data were obtained from chart reviews of patients with positive cultures. Antimicrobial susceptibility testing and cell wall fatty acid analysis were performed for each DF-3 isolated. Eight isolates of DF-3 were obtained over a period of 8 months. All patients either had severe underlying disease or were immunocompromised, including three patients coinfected with human immunodeficiency virus and two patients with inflammatory bowel disease. The spectrum of clinical disease ranged from chronic diarrhea with a well-defined response to therapy for DF-3 to an asymptomatic carrier state. Cell wall fatty acid analysis of these isolates demonstrated a consistent pattern with a large peak of 12-methyltetradecanoate. DF-3, a fastidious gram-negative coccobacillus, can be recovered from stool cultures of immunocompromised patients by using selective media. The presence of 12-methyltetradecanoate in cell wall fatty acid analysis assists in identification. The increased use of a selective medium-(cefoperazone-vancomycin-amphotericin B) in the evaluation of diarrhea in immunocompromised hosts, including persons with inflammatory bowel disease, may better define the association of DF-3 with human gastrointestinal disease.
Carbonetto, C H; Malchiodi, E L; Chiaramonte, M; Durante de Isola, E; Fossati, C A; Margni, R A
By affinity chromatography with a monoclonal antibody (163B6), obtained in our laboratory, we have isolated a T. cruzi antigen which could be useful for differential diagnosis of Chagas' disease from leishmaniasis. This antigen, a 52-kD protein, reacted with all sera from Chagas' disease patients tested but not with sera from patients with leishmania, in ELISA. The 52-kD antigen is widely distributed in the Trypanosoma genus since the 163B6 monoclonal antibody reacts with T. rangeli and 8 strains and a clone of T. cruzi epimastigotes. Images Fig. 1 Fig. 2 PMID:2119921
Wilde, Henry; Suankratay, Chusana
Enteric fever, typhus, leptospirosis, dengue, melioidosis, and tuberculous meningitis present urgent diagnostic problems that require experience and clinical judgment to make early evidence-based management decisions. Basic and applied research dealing with reliable antigen-based diagnostics has been published and confirmed for several of these infections. This should have initiated commercial production but has not. Established international firms see little profit in such diagnostic kits since they would be used in poor countries with little prospects for return of investment capital. We attempt to illustrate this issue, using common causes of acute febrile illnesses in the Southeast Asian region. We believe that rapid diagnostic technology could prevent significant delay in starting appropriate therapy, reduce hospital expenses, and even save lives.
An, So Jung; Woo, Joo Sung; Chae, Myung Hwa; Kothari, Sudeep; Carbis, Rodney
The majority of conjugate vaccines focus on inducing an antibody response to the polysaccharide antigen and the carrier protein is present primarily to induce a T-cell dependent response. In this study conjugates consisting of poly(ribosylribitolphosphate) (PRP) purified from Haemophilus influenzae Type b bound to Hepatitis B virus surface antigen (HBsAg) virus like particles were prepared with the aim of inducing an antibody response to not only the PRP but also the HBsAg. A conjugate consisting of PRP bound to HBsAg via an adipic acid dihydrazide (ADH) spacer induced strong IgG antibodies to both the PRP and HBsAg. When conjugation was performed without the ADH spacer the induction of an anti-PRP response was equivalent to that seen by conjugate with the ADH spacer, however, a negligible anti-HBsAg response was induced. For comparison, PRP was conjugated to diphtheria toxoid (DT) and Vi polysaccharide purified from Salmonella Typhi conjugated to HBsAg both using an ADH spacer. The PRPAH-DT conjugate induced strong anti-PRP and anti-DT responses, the Vi-AHHBsAg conjugate induced a good anti-HBsAg response but not as strong as that induced by the PRPAH-HBsAg conjugate. This study demonstrated that in mice it was possible to induce robust antibody responses to both polysaccharide and carrier protein provided the conjugate has certain physico-chemical properties. A PRPAH-HBsAg conjugate with the capacity to induce anti-PRP and anti-HBsAg responses could be incorporated into a multivalent pediatric vaccine and simplify formulation of such a vaccine.
Several serologic tests designed to detect antibodies to immunodominant Mycobacterium bovis antigens have recently emerged as ancillary tests for the detection of bovine tuberculosis in cattle, particularly when applied after injection of purified protein derivative (PPD) for skin test that signific...
Mackroth, Maria S.; Tappe, Dennis; Tannich, Egbert; Addo, Marylyn; Rothe, Camilla
Plasmodium knowlesi has been identified in the last decade as a fifth species causing malaria in areas of South East Asia. Due to its short erythrocytic cycle, rapid development of high parasitemia and severe manifestations are frequently observed. Therefore, prompt diagnosis of infection is essential to prevent complications, but the low sensitivity of rapid diagnostic tests for P knowlesi pose a diagnostic challenge in acute settings. In this study, we report the case of a German traveler to Thailand, who was treated for P knowlesi malaria after returning to Germany. Rapid antigen test for malaria was negative on presentation. Diagnosis of a nonfalciparum malaria was made based on microscopy, and species definition was determined using polymerase chain reaction technique. PMID:27006963
Becker, S L; Chatigre, J K; Gohou, J-P; Coulibaly, J T; Leuppi, R; Polman, K; Chappuis, F; Mertens, P; Herrmann, M; N'Goran, E K; Utzinger, J; von Müller, L
Infectious diarrhoea ranks among the leading causes of morbidity worldwide. Although most acute diarrhoeal episodes are self-limiting, the diagnosis and treatment of persistent diarrhoea (≥2 weeks) are cumbersome and require laboratory identification of the causative pathogen. Stool-based PCR assays have greatly improved the previously disappointing pathogen detection rates in high-income countries, but there is a paucity of quality data from tropical settings. We performed a case-control study to elucidate the spectrum of intestinal pathogens in patients with persistent diarrhoea and asymptomatic controls in southern Côte d'Ivoire. Stool samples from 68 patients and 68 controls were obtained and subjected to molecular multiplex testing with the Luminex(®) Gastrointestinal Pathogen Panel (GPP), microscopy and rapid antigen detection tests for the diagnosis of diarrhoeagenic pathogens. Overall, 20 different bacteria, parasites and viruses were detected by the suite of diagnostic methods employed. At least one pathogen was observed in 84% of the participants, and co-infections were observed in >50% of the participants. Enterotoxigenic Escherichia coli (32%), Giardia intestinalis (29%) and Shigella species (20%) were the predominant pathogens, and Strongyloides stercoralis (10%) was the most prevalent helminth. Pathogen frequencies and numbers of co-infections were similar in patients and controls. Although the Luminex(®) GPP detects a broad range of pathogens, microscopy for helminths and intestinal protozoa remains necessary to cover the full aetiological spectrum in tropical settings. We conclude that highly sensitive multiplex PCR assays constitute a useful screening tool, but that positive results might need to be confirmed by independent methods to discriminate active infection from asymptomatic faecal shedding of nucleic acids.
Huaman, Maria Cecilia; Sato, Yoshiya; Aguilar, Jose Luis; Terashima, Angelica; Guerra, Humberto; Gotuzzo, Eduardo; Kanbara, Hiroji
Routine microscopical examination of stool specimens for diagnosis of strongyloidiasis is insensitive and serological methods using Strongyloides stercoralis antigen are at present not available for field studies. We evaluated 2 techniques, enzyme-linked immunosorbent assay (ELISA) and gelatin particle indirect agglutination (GPIA), using an antigen obtained from the rodent parasite, S. venezuelensis. Fifty-four Peruvian patients with different clinical forms of strongyloidiasis were studied: 12 asymptomatic, 31 symptomatic, and 11 hyperinfection cases. Our results demonstrate that both ELISA and GPIA using S. venezuelensis antigen are useful for diagnosis of strongyloidiasis, with sensitivities of 74.1% and 98.2%, respectively and a specificity of 100% for both techniques. We found that GPIA is a highly sensitive test for patients with suspected chronic infection and/or hyperinfection. In the hyperinfection cases, significantly lower concentrations of specific immunoglobulin antibodies and eosinophils (P < 0.001) were found compared with the asymptomatic and symptomatic cases.
Davison, H. C.; Thrusfield, M. V.; Muharsini, S.; Husein, A.; Partoutomo, S.; Rae, P. F.; Masake, R.; Luckins, A. G.
Two Ag-ELISAs, an IgG-specific antibody detection ELISA (IgG ELISA) and a card agglutination test (CATT) for the detection of Trypanasoma evansi infections in buffaloes in Indonesia, were compared. Diagnostic sensitivity estimates were obtained by testing sera from 139 Indonesian buffaloes which had been found to be infected by parasitological tests. Diagnostic specificity was estimated by testing sera from 263 buffaloes living in Australia. Response-operating characteristic curves were constructed, and optimal ELISA cut-off values, which minimized the number of false-negative and false-positive results, were chosen. The IgG ELISA had the highest sensitivity (89%) and the CATT had the highest specificity (100%). There was a significant difference between the sensitivities (71 and 81%), but not between the specificities (75 and 78%), of the two Ag-ELISAs. The four tests were further compared by calculation of post-test probabilities of infection for positive and negative test results using a range of prevalence values, and likelihood ratios. The results suggested that the CATT was the best test to 'rule-in' infection (i.e. the highest probability of infection in test-positive animals) and the IgG ELISA was the best test to 'rule-out' infection (i.e. the lowest probability of infection in test-negative animals). PMID:10487651
Davison, H C; Thrusfield, M V; Muharsini, S; Husein, A; Partoutomo, S; Rae, P F; Masake, R; Luckins, A G
Two Ag-ELISAs, an IgG-specific antibody detection ELISA (IgG ELISA) and a card agglutination test (CATT) for the detection of Trypanasoma evansi infections in buffaloes in Indonesia, were compared. Diagnostic sensitivity estimates were obtained by testing sera from 139 Indonesian buffaloes which had been found to be infected by parasitological tests. Diagnostic specificity was estimated by testing sera from 263 buffaloes living in Australia. Response-operating characteristic curves were constructed, and optimal ELISA cut-off values, which minimized the number of false-negative and false-positive results, were chosen. The IgG ELISA had the highest sensitivity (89%) and the CATT had the highest specificity (100%). There was a significant difference between the sensitivities (71 and 81%), but not between the specificities (75 and 78%), of the two Ag-ELISAs. The four tests were further compared by calculation of post-test probabilities of infection for positive and negative test results using a range of prevalence values, and likelihood ratios. The results suggested that the CATT was the best test to 'rule-in' infection (i.e. the highest probability of infection in test-positive animals) and the IgG ELISA was the best test to 'rule-out' infection (i.e. the lowest probability of infection in test-negative animals).
Kohn, Barbara; Classe, Gabriele; Weingart, Christiane
In transfusion medicine, blood typing is an integral part of pretransfusion testing. The objective of the current study was the clinical evaluation of an automated canine cartridge dog erythrocyte antigen (DEA) 1.1 blood-typing method (QuickVet/RapidVet) and comparison of the results with a gel column-based method (ID-Gel Test Canine DEA 1.1). Ethylenediamine tetra-acetic acid-anticoagulated blood samples from 11 healthy and 85 sick dogs were available for typing. Before blood typing, all samples were tested for agglutination and hemolysis. All samples were tested once or multiple times with both methods according to the manufacturer's guidelines. With the gel method, 53 dogs tested DEA 1.1 positive and 42 dogs DEA 1.1 negative; blood typing was not possible due to erythrocyte autoagglutination in 1 dog. With the cartridge test, 53 samples tested DEA 1.1 positive, 34 samples tested DEA 1.1 negative, and 6 results were inconclusive (3 samples were not included due to autoagglutination or severe hemolysis). Without taking the inconclusive samples into account, the agreement between both methods was 96.5%. The sensitivity and specificity for samples that were definitively typed by both methods were 100% and 91.9%, respectively. The cartridge test was suitable for in-clinic canine DEA 1.1 blood typing, although some discrepancies compared to the gel method existed. The cartridge test is software-directed, is easy to use, and does not require user interpretation, but preanalytical guidelines (sample evaluation for agglutination and hemolysis) have to be followed. For inconclusive results, an alternate blood-typing method should be performed.
Santivañez, Saul J; Rodriguez, Mary L; Rodriguez, Silvia; Sako, Yashuito; Nkouawa, Agathe; Kobayashi, Yukuharu; Sotomayor, Alfredo L; Peralta, Julio E; Valcarcel, Maria; Gonzalez, Armando E; Garcia, Hector H; Ito, Akira
Diagnosis of cystic echinococcosis (CE) is based on the identification of the cyst(s) by imaging, using immunodiagnostic tests mainly as complementary tools in clinical settings. Among the antigens used for immunodiagnosis, previous studies described a good performance of the recombinant antigen B8/1 (rAgB) in an enzyme-linked immunosorbent assay (ELISA) format; however, in remote parts of areas where the disease is endemic, the implementation of an ELISA is difficult, so a more simple, rapid, and reliable method such as the immunochromatographic test (ICT) is required. In this study, using a set of 50 serum samples from patients with surgically confirmed CE, we compared the performance of an ICT and that of an ELISA using the rAgB. The overall sensitivities of ICT and ELISA were not statistically different (78% versus 72%; P = 0.36). The overall agreement between both tests was moderate (κ = 0.41; P < 0.01). Concordance between ICT and ELISA was substantial or almost perfect for patients with liver involvement (κ = 0.65; P < 0.001) and patients with more than one hydatid cyst (κ = 0.82; P < 0.001), respectively. Moreover, specificity analysis using a total of 88 serum samples from healthy individuals (n = 20) and patients (n = 68) with other parasitic infections revealed that ICT had a specificity of 89.8%. ICT and ELISA had similar performance for the detection of specific antibodies to E. granulosus, and ICT had a high specificity, opening the possibility of using ICT as a screening tool in rural settings.
Rodriguez, Mary L.; Rodriguez, Silvia; Sako, Yashuito; Nkouawa, Agathe; Kobayashi, Yukuharu; Sotomayor, Alfredo L.; Peralta, Julio E.; Valcarcel, Maria; Gonzalez, Armando E.; Garcia, Hector H.; Ito, Akira
Diagnosis of cystic echinococcosis (CE) is based on the identification of the cyst(s) by imaging, using immunodiagnostic tests mainly as complementary tools in clinical settings. Among the antigens used for immunodiagnosis, previous studies described a good performance of the recombinant antigen B8/1 (rAgB) in an enzyme-linked immunosorbent assay (ELISA) format; however, in remote parts of areas where the disease is endemic, the implementation of an ELISA is difficult, so a more simple, rapid, and reliable method such as the immunochromatographic test (ICT) is required. In this study, using a set of 50 serum samples from patients with surgically confirmed CE, we compared the performance of an ICT and that of an ELISA using the rAgB. The overall sensitivities of ICT and ELISA were not statistically different (78% versus 72%; P = 0.36). The overall agreement between both tests was moderate (κ = 0.41; P < 0.01). Concordance between ICT and ELISA was substantial or almost perfect for patients with liver involvement (κ = 0.65; P < 0.001) and patients with more than one hydatid cyst (κ = 0.82; P < 0.001), respectively. Moreover, specificity analysis using a total of 88 serum samples from healthy individuals (n = 20) and patients (n = 68) with other parasitic infections revealed that ICT had a specificity of 89.8%. ICT and ELISA had similar performance for the detection of specific antibodies to E. granulosus, and ICT had a high specificity, opening the possibility of using ICT as a screening tool in rural settings. PMID:26447116
Two purified-protein derivative (PPD) tuberculin skin test (TST) antigen solutions are approved by the U.S. Food and Drug Administration (FDA): Tubersol (Sanofi Pasteur Limited) and Aplisol (JHP Pharmaceuticals, LLC). Tubersol was out of production in late 2012 through April 2013. Shortages of Aplisol have resulted from increased demand as practitioners have sought a substitute for Tubersol. Tubersol production resumed in May 2013, and supplies had been nearly restored by early June. However, in mid-July, state tuberculosis (TB) control officials notified CDC of difficulty obtaining Tubersol and Aplisol. Sanofi Pasteur notified FDA of a temporary delay in the availability of tuberculin in the 10-dose and 50-dose presentations. In mid-October, the 10-dose presentation was being returned to market, on allocation, which means that historical purchasing practices determine the amount that customers are allotted. In late October, the 50-dose presentation was being returned to market, also on allocation, one vial per historical customer per month. Supplies are forecast to approach normal during January 2014, after distributors have restored their supply chains. A compensatory surge in testing after deferment of testing during the periods of shortage might cause further temporary instability of supplies. In mid-August 2013, officials in 29 of 52 U.S. jurisdictions noted a shortage of at least one PPD TST antigen solution in health departments to the extent that it interrupted activities. This report includes a summary of the extent and effects of the shortages and a reiteration of advice on how to adapt to them.
Lu, Wenting; Wang, Kan; Xiao, Kun; Qin, Weijian; Hou, Yafei; Xu, Hao; Yan, Xinyu; Chen, Yanrong; Cui, Daxiang; He, Jinghua
A novel immunomagnetic nanobeads -based lateral flow test strip was developed for the simultaneous quantitative detection of neuron specific enolase (NSE) and carcinoembryonic antigen (CEA), which are sensitive and specific in the clinical diagnosis of small cell lung cancer. Using this nanoscale method, high saturation magnetization, carboxyl-modified magnetic nanobeads were successfully synthesized. To obtain the immunomagnetic probes, a covalent bioconjugation of the magnetic nanobeads with the antibody of NSE and CEA was carried out. The detection area contained test line 1 and test line 2 which captured the immune complexes sensitively and formed sandwich complexes. In this assay, cross-reactivity results were negative and both NSE and CEA were detected simultaneously with no obvious influence on each other. The magnetic signal intensity of the nitrocellulose membrane was measured by a magnetic assay reader. For quantitative analysis, the calculated limit of detection was 0.094 ng/mL for NSE and 0.045 ng/mL for CEA. One hundred thirty clinical samples were used to validate the test strip which exhibited high sensitivity and specificity. This dual lateral flow test strip not only provided an easy, rapid, simultaneous quantitative detection strategy for NSE and CEA, but may also be valuable in automated and portable diagnostic applications. PMID:28186176
Taniuchi, Mami; Verweij, Jaco J; Sethabutr, Orntipa; Bodhidatta, Ladaporn; Garcia, Lynne; Maro, Athanasia; Kumburu, Happiness; Gratz, Jean; Kibiki, Gibson; Houpt, Eric R
Cyclospora, Cystoisospora, and Microsporidia are eukaryotic enteropathogens that are difficult to detect in stool samples because they require special stains and microscopy. We developed a multiplex polymerase chain reaction (PCR) reaction with 4 primer sets to amplify Cyclospora cayetanensis, Cystoisospora belli, Enterocytozoon bieneusi, and Encephalitozoon intestinalis. Detection of the amplicon is through specific probes coupled to Luminex beads. Sensitivity of the assay was evaluated using Encephalitozoon intestinalis spores and revealed detection of 10(1) spores spiked into stool. No cross-reactivity was observed. We evaluated the assay on diarrheal specimens from Thailand, Tanzania, Indonesia, and the Netherlands that had been previously tested by microscopy, and the assay yielded 87-100% sensitivity and 88-100% specificity. Microscopy-negative/PCR-positive samples had lower Luminex values, suggesting they were true but with lower burden infections. In summary, this is a convenient single PCR reaction that can detect Cyclospora, Cystoisospora, and Microsporidia without the need for cumbersome microscopic analysis.
Taniuchi, Mami; Verweij, Jaco J.; Sethabutr, Orntipa; Bodhidatta, Ladaporn; Garcia, Lynne; Maro, Athanasia; Kumburu, Happiness; Gratz, Jean; Kibiki, Gibson; Houpt, Eric R.
Cyclospora, Cystoisospora, and Microsporidia are eukaryotic enteropathogens that are difficult to detect in stool samples because they require special stains and microscopy. We developed a multiplex PCR reaction with 4 primer sets to amplify Cyclospora cayetanensis, Cystoisospora belli, Enterocytozoon bieneusi, and Encephalitozoon intestinalis. Detection of the amplicon is through specific probes coupled to Luminex beads. Sensitivity of the assay was evaluated using Encephalitozoon intestinalis spores and revealed detection of 101 spores spiked into stool. No cross reactivity was observed. We evaluated the assay on diarrheal specimens from Thailand, Tanzania, Indonesia, and the Netherlands that had been previously tested by microscopy and the assay yielded 87–100% sensitivity and 88–100% specificity. Microscopy negative/PCR positive samples had lower Luminex values suggesting they were true but lower burden infections. In summary this is a convenient single PCR reaction that can detect Cyclospora, Cystoisospora, and Microsporidia without the need for cumbersome microscopic analysis. PMID:21982218
To, Kelvin K W; Cheng, Vincent C C; Tang, Bone S F; Fan, Yiu-Wah; Yuen, Kwok-Yung
This is the first report of a small-colony variant Cryptococcus neoformans isolated from the cerebrospinal fluid of a patient with cystopleural shunt associated chronic meningitis. Cryptococcal antigen testing of the cerebrospinal fluid and the serum were both negative. The atypical morphology and the false-negative test may lead to delay of diagnosis and treatment.
Mas-Coma, S; Bargues, M D; Valero, M A
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.
Alkmin, M G; Landgraf, I M; Shimizu, S H
Infection with Neisseria meningitidis group B has been difficult to detect, partly because this bacterial group's polysaccharide is a weak immunogen. This article describes work carried out to test a new procedure (MB-Dot-ELISA) employing a high-titered horse antiserum for detection of N. meningitidis group B antigens. The study assayed cerebrospinal fluid samples from 585 subjects, 574 with suspected meningitis cases and 11 with neurologic disorders. The results of the assay indicated a sensitivity of 0.991 and a specificity of 0.826. These results were superior to those obtained with latex agglutination and in substantial agreement with the results of counterimmunoelectrophoresis and bacteriologic methods. Overall, the MB-Dot-ELISA was found to be sensitive, inexpensive, and suitable for public health laboratory investigations.
Gyurech, Danielle; Schilling, Julian; Schmidt-Chanasit, Jonas; Cassinotti, Pascal; Kaeppeli, Franz; Dobec, Marinko
We report the first case of an acute Zika virus infection imported into Switzerland by a traveller returning from Canoa Quebrada, Ceará state, in the north-eastern part of Brazil. Due to a false positive dengue virus NS1 antigen test, IgG antibody seroconversion and a suggestive clinical picture,an acute dengue fever was initially considered. However, because of lack of specific IgM-antibodies, stationary IgG antibody titre and a negative dengue virus PCR test result, a dengue virus infection was excluded and a cross-reaction with other, causative flaviviruses was postulated. Based on recent reports of Zika fever cases in the north-eastern parts of Brazil, an acute Zika virus infection was suspected. Because of a lack of commercially available Zika virus diagnostic tests, the case was confirmed in the WHO reference laboratory. As the clinical presentation of Zika virus infection can be confused with dengue fever and chikungunya fever, and because of possible public health implications, all patients returning from affected areas should be additionally tested for Zika virus. This case illustrates the urgent medical need for a broadly available assay capable of differentiating Zika from Dengue infections.
Knapp, Jenny; Millon, Laurence; Mouzon, Lorane; Umhang, Gérald; Raoul, Francis; Ali, Zeinaba Said; Combes, Benoît; Comte, Sébastien; Gbaguidi-Haore, Houssein; Grenouillet, Frédéric; Giraudoux, Patrick
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.
Stothard, J Russell; Kabatereine, Narcis B; Tukahebwa, Edridah M; Kazibwe, Francis; Rollinson, David; Mathieson, William; Webster, Joanne P; Fenwick, Alan
An evaluation of a commercially available antigen capture dipstick that detects schistosome circulating cathodic antigen (CCA) in urine was conducted in representative endemic areas for intestinal and urinary schistosomiasis in Uganda and Zanzibar, respectively. Under field-based conditions, the sensitivity (SS) and specificity (SP) of the dipstick was 83 and 81% for detection of Schistosoma mansoni infections while positive predictive (PPV) and negative predictive values (NPV) were 84%. Light egg-positive infections were sometimes CCA-negative while CCA-positives included egg-negative children. A positive association between faecal egg output and intensity of CCA test band was observed. Estimating prevalence of intestinal schistosomiasis by school with dipsticks was highly correlated (r=0.95) with Kato-Katz stool examinations, typically within +/-8.5%. In Zanzibar, however, dipsticks totally failed to detect S. haematobium despite examining children with egg-patent schistosomiasis. This was also later corroborated by further surveys in Niger and Burkina Faso. Laboratory testing of dipsticks with aqueous adult worm lysates from several reference species showed correct functioning, however, dipsticks failed to detect CCA in urine from S. haematobium-infected hamsters. While CCA dipsticks are a good alternative, or complement, to stool microscopy for field diagnosis of intestinal schistosomiasis, they have no proven value for field diagnosis of urinary schistosomiasis. At approximately 2.6 US dollars per dipstick, they are presently too expensive to be cost-effective for wide scale use in disease mapping surveys unless Lot Quality Assurance Sampling (LQAS) strategies are developed.
Tam, Ka Ian; Esona, Mathew D; Williams, Alice; Ndze, Valantine N; Boula, Angeline; Bowen, Michael D
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.
Tam, Ka Ian; Esona, Mathew D.; Williams, Alice; Ndze, Valentine N.; Boula, Angeline; Bowen, Michael D.
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
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
Colley, Daniel G.; Binder, Sue; Campbell, Carl; King, Charles H.; Tchuem Tchuenté, Louis-Albert; N'Goran, Eliézer K.; Erko, Berhanu; Karanja, Diana M. S.; Kabatereine, Narcis B.; van Lieshout, Lisette; Rathbun, Stephen
We evaluated a commercial point-of-care circulating cathodic antigen (POC-CCA) test for assessing Schistosoma mansoni infection prevalence in areas at risk. Overall, 4,405 school-age children in Cameroon, Côte d'Ivoire, Ethiopia, Kenya, and Uganda provided urine for POC-CCA testing and stool for Kato-Katz assays. By latent class analysis, one POC-CCA test was more sensitive (86% versus 62%) but less specific (72% versus ∼100%) than multiple Kato-Katz smears from one stool. However, only 1% of POC-CCA tests in a non-endemic area were false positives, suggesting the latent class analysis underestimated the POC-CCA specificity. Multivariable modeling estimated POC-CCA as significantly more sensitive than Kato-Katz at low infection intensities (< 100 eggs/gram stool). By linear regression, 72% prevalence among 9–12 year olds by POC-CCA corresponded to 50% prevalence by Kato-Katz, whereas 46% POC-CCA prevalence corresponded to 10% Kato-Katz prevalence. We conclude that one urine POC-CCA test can replace Kato-Katz testing for community-level S. mansoni prevalence mapping. PMID:23339198
Reeves, M W; McGrew, B E; McLaurin, B; Pine, L
A total of 13 egg lecithins, 12 beef heart lecithins, and 15 beef heart cardiolipins were assayed for the ability to function in the Venereal Disease Research Laboratory microflocculation test, as well as for purity, fatty acid composition, free amines, metals, and products of oxidation. We found that the presence of peroxides and oxidation-related ultraviolet-absorbing chromophores showed a close inverse relationship to acceptable serological activity. The degree of purity of the lipids had only a slight influence on serological activity, whereas fatty acid composition, saturation, and configuration had none at all. We did not detect contaminating iron, copper, cobalt, nickel, or free amines in these lipids. We discuss the implications of our findings for improving the chemical standards for these lipids. Images PMID:7263853
Pishkari, S; Shojaee, S; Keshavarz, H; Salimi, M; Mohebali, M
The present study was performed to compare the soluble, whole and excretory/secretary antigens of Toxoplasma gondii (RH strain) in diagnosis of toxoplasmosis by ELISA method. Tachyzoites of T. gondii, RH strain were injected in intra-peritoneal cavity of BALB/c mice, after 4 days tachyzoites were harvested by peritoneal washing of the mice. For soluble antigen, exudates were centrifuged and sediment sonicated and then centrifuged at 4 °C, 1 h, supernatant collected and density of protein determined by Bradford method. For whole antigen after collecting, washing and centrifuging of peritoneal fluid the tachyzoites sediment was counted. In excretory/secretary antigen 1.5 × 10(8) tachyzoites were transferred in 1 ml tube of saline and incubated under mild agitation and after centrifuging, supernatant was collected and protein density determined by Bradford method. 176 human serum samples were evaluated for T. gondii IgG antibody with prepared antigens, and finally serum samples were evaluated by commercial ELISA kit (Trinity, USA) which was considered as gold standard method. In this study sensitivity and specificity of prepared antigens compared with commercial kit in ELISA method. Sensitivity and specificity of soluble antigen was 91.4 and 74.5 %, in whole antigen these parameters were 77.1 and 77.3 % and in excretory/secretary antigen were 28.5 and 74.5 % respectively. Soluble antigen had high levels of sensitivity and specificity in ELISA method and the results were rather resemble to commercial kit (Trinity, USA).
Saukkoriipi, Annika; Pascal, Thierry; Palmu, Arto A
We evaluated the BinaxNOW® urine antigen test in elderly. For fresh un-concentrated urine samples, the sensitivity for pneumococcal pneumonia was 63% and specificity 97%. After freezing and concentration, the results comparable to positive control line in intensity at 60 min gave high sensitivity (81%) with no loss in specificity (96%).
Ahmed, Farid E; Ahmed, Nancy C; Vos, Paul W; Bonnerup, Chris; Atkins, James N; Casey, Michelle; Nuovo, Gerard J; Naziri, Wade; Wiley, John E; Mota, Helvecio; Allison, Ron R
R-222 and miR-938) had decreased expression in the stool of patients with colon cancer, which was also more pronounced from early to later TNM stages. Results from colon mucosal tissues were similar to those from stool samples, although with more apparent changes in expression. Cytological studies on purified stool colonocytes that employed Giemsa staining showed 80% sensitivity for detecting tumor cells in stool smears. The performance characteristics of the test confirmed that stool is a medium well-suited for colon cancer screening, and that the quantitative changes in the expression of few mature miRNA molecules in stool associated with colon cancer progression provided for more sensitive and specific non-invasive diagnostic markers than tests currently available on the market. Thus, a larger prospective and properly randomized validation study of control individuals and patients exhibiting various stages of colon cancer progression (TNM stages 0-IV) is now needed in order to standardize test conditions, and provide a means for determining the true sensitivity and specificity of a miRNA screening approach in stool for the non-invasive detection of colon cancer, particularly at an early stage (0-I). Eventually, we will develop a chip to enhance molecular screening for colon cancer, as has been accomplished for the detection of genetically-modified organisms (GMOs) in foods.
Prim, Núria; Escamilla, Pilar; Solé, Roser; Llovet, Teresa; Soriano, Germán; Muñoz, Carmen
Entamoeba histolytica antigen assays on stool are widely used to diagnose amebiasis. We report a case of confirmed amebic colitis with a false-negative antigen detection that became positive after treatment. Our results indicate that these assays may underdiagnose acute amebic infection when used alone and should be used cautiously.
Gandasegui, Javier; Bajo Santos, Cristina; López-Abán, Julio; Saugar, José María; Rodríguez, Esperanza; Vicente, Belén; Muro, Antonio
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
Momtaz, Hassan; Souod, Negar; Dabiri, Hossein; Sarshar, Meysam
AIM: To compare genotype of Helicobacter pylori (H. pylori) isolated from saliva, dental plaques, gastric biopsy, and stool of each patient in order to evaluate the mode of transmission of H. pylori infection. METHODS: This cross-sectional descriptive study was performed on 300 antral gastric biopsy, saliva, dental plaque and stool samples which were obtained from patients undergoing upper gastrointestinal tract endoscopy referred to endoscopy centre of Hajar hospital of Shahrekord, Iran from March 2010 to February 2011. Initially, H. pylori strains were identified by rapid urease test (RUT) and polymerase chain reaction (PCR) were applied to determine the presence of H. pylori (ureC) and for genotyping of voculating cytotoxin gene A (vacA) and cytotoxin associated gene A (cagA) genes in each specimen. Finally the data were analyzed by using statistical formulas such as Chi-square and Fisher’s exact tests to find any significant relationship between these genes and patient’s diseases. P < 0.05 was considered statistically significant. RESULTS: Of 300 gastric biopsy samples, 77.66% were confirmed to be H. pylori positive by PCR assay while this bacterium were detected in 10.72% of saliva, 71.67% of stool samples. We were not able to find it in dental plaque specimens. The prevalence of H. pylori was 90.47% among patients with peptic ulcer disease (PUD), 80% among patients with gastric cancer, and 74.13% among patients with none ulcer dyspepsia (NUD) by PCR assay. The evaluation of vacA and cagA genes showed 6 differences between gastric biopsy and saliva specimens and 11 differences between gastric and stool specimens. 94.42% of H. pylori positive specimens were cagA positive and all samples had amplified band both for vacA s and m regions. There was significant relationship between vacA s1a/m1a and PUD diseases (P = 0.04), s2/m2 genotype and NUD diseases (P = 0.05). No statically significant relationship was found between cagA status with clinical outcomes and
Gazzano, Vincent; Berger, Anne; Benito, Yvonne; Freydiere, Anne-Marie; Tristan, Anne; Boisset, Sandrine; Carricajo, Anne; Poyart, Claire; Vandenesch, François
Rapid antigen detection tests (RADTs) for group A streptococci (GAS) are widely used for diagnosing acute pharyngitis, which has led to a considerable reduction in antibiotic prescriptions over the past decade. Beyond this intended use, their reassessment on invasive samples may be relevant in the management of life-threatening GAS infections. To this end, we evaluated the performances of three RADTs, culture, GAS PCR, and 16S rRNA gene PCR assays, and compared them with a composite gold standard (GAS-PCR assay and/or culture) for the diagnosis of severe GAS infection. A total of 192 specimens from deep-tissue (mostly normally sterile) sites enriched for 75 GAS-positive samples were enrolled in the study. The three evaluated RADTs showed sensitivities ranging from 88.0% to 94.7% versus 98.7% for GAS PCR, 84% for 16S rRNA gene PCR, and 77.3% for culture. The sensitivities of the ImmunoCard STAT! Strep A test (Meridian Bioscience) and the NADAL Strep A strip (Nal Von Minden) were similar to that of GAS PCR (P = 0.25 and 0.03, respectively) and higher than that of culture (P = 0.001 and 0.006, respectively), whereas the SD Bioline Strep A test strip (Standard Diagnostics) showed a performance similar to that of culture (P = 0.02). The three RADTs detected 10 distinct emm types, including a predominance of emm 1 (33.3%), emm 89 (10.6%), and emm 12 (7.6%). No false-positive results were observed, leading to a specificity of 100% for all the evaluated RADTs. The GAS RADTs turned out to be sensitive, specific, and easy-to-use tools that may aid in the management of invasive GAS infections in 24/7 point-of-care laboratories by enabling early diagnosis and focused therapy. PMID:26818671
Green, Hefziba; Steinmetz, Tali; Leibovici, Leonard; Paul, Mical
The diagnosis of Legionnaires' disease (LD) is based on the isolation of Legionella spp., a 4-fold rise in antibodies, a positive urinary antigen (UA), or direct immunofluorescence tests. PCR is not accepted as a diagnostic tool for LD. This systematic review assesses the diagnostic accuracy of PCR in various clinical samples with a direct comparison versus UA. We included prospective or retrospective cohort and case-control studies. Studies were included if they used the Centers for Disease Control and Prevention consensus definition criteria of LD or a similar one, assessed only patients with clinical pneumonia, and reported data for all true-positive, false-positive, true-negative, and false-negative results. Two reviewers abstracted data independently. Risk of bias was assessed using Quadas-2. Summary sensitivity and specificity values were estimated using a bivariate model and reported with a 95% confidence interval (CI). Thirty-eight studies were included. A total of 653 patients had confirmed LD, and 3,593 patients had pneumonia due to other pathogens. The methodological quality of the studies as assessed by the Quadas-2 tool was poor to fair. The summary sensitivity and specificity values for diagnosis of LD in respiratory samples were 97.4% (95% CI, 91.1% to 99.2%) and 98.6% (95% CI, 97.4% to 99.3%), respectively. These results were mainly unchanged by any covariates tested and subgroup analysis. The diagnostic performance of PCR in respiratory samples was much better than that of UA. Compared to UA, PCR in respiratory samples (especially in sputum samples or swabs) revealed a significant advantage in sensitivity and an additional diagnosis of 18% to 30% of LD cases. The diagnostic performance of PCR in respiratory samples was excellent and preferable to that of the UA. Results were independent on the covariate tested. PCR in respiratory samples should be regarded as a valid tool for the diagnosis of LD. PMID:26659202
Avni, Tomer; Bieber, Amir; Green, Hefziba; Steinmetz, Tali; Leibovici, Leonard; Paul, Mical
The diagnosis of Legionnaires' disease (LD) is based on the isolation of Legionella spp., a 4-fold rise in antibodies, a positive urinary antigen (UA), or direct immunofluorescence tests. PCR is not accepted as a diagnostic tool for LD. This systematic review assesses the diagnostic accuracy of PCR in various clinical samples with a direct comparison versus UA. We included prospective or retrospective cohort and case-control studies. Studies were included if they used the Centers for Disease Control and Prevention consensus definition criteria of LD or a similar one, assessed only patients with clinical pneumonia, and reported data for all true-positive, false-positive, true-negative, and false-negative results. Two reviewers abstracted data independently. Risk of bias was assessed using Quadas-2. Summary sensitivity and specificity values were estimated using a bivariate model and reported with a 95% confidence interval (CI). Thirty-eight studies were included. A total of 653 patients had confirmed LD, and 3,593 patients had pneumonia due to other pathogens. The methodological quality of the studies as assessed by the Quadas-2 tool was poor to fair. The summary sensitivity and specificity values for diagnosis of LD in respiratory samples were 97.4% (95% CI, 91.1% to 99.2%) and 98.6% (95% CI, 97.4% to 99.3%), respectively. These results were mainly unchanged by any covariates tested and subgroup analysis. The diagnostic performance of PCR in respiratory samples was much better than that of UA. Compared to UA, PCR in respiratory samples (especially in sputum samples or swabs) revealed a significant advantage in sensitivity and an additional diagnosis of 18% to 30% of LD cases. The diagnostic performance of PCR in respiratory samples was excellent and preferable to that of the UA. Results were independent on the covariate tested. PCR in respiratory samples should be regarded as a valid tool for the diagnosis of LD.
Patra, Kailash P; Saito, Mayuko; Atluri, Vidya L; Rolán, Hortensia G; Young, Briana; Kerrinnes, Tobias; Smits, Henk; Ricaldi, Jessica N; Gotuzzo, Eduardo; Gilman, Robert H; Tsolis, Renee M; Vinetz, Joseph M
Human brucellosis is most commonly diagnosed by serology based on agglutination of fixed Brucella abortus as antigen. Nucleic acid amplification techniques have not proven capable of reproducibly and sensitively demonstrating the presence of Brucella DNA in clinical specimens. We sought to optimize a monoclonal antibody-based assay to detect Brucella melitensis lipopolysaccharide in blood by conjugating B. melitensis LPS to keyhole limpet hemocyanin, an immunogenic protein carrier to maximize IgG affinity of monoclonal antibodies. A panel of specific of monoclonal antibodies was obtained that recognized both B. melitensis and B. abortus lipopolysaccharide epitopes. An antigen capture assay was developed that detected B. melitensis in the blood of experimentally infected mice and, in a pilot study, in naturally infected Peruvian subjects. As a proof of principle, a majority (7/10) of the patients with positive blood cultures had B. melitensis lipopolysaccharide detected in the initial blood specimen obtained. One of 10 patients with relapsed brucellosis and negative blood culture had a positive serum antigen test. No seronegative/blood culture negative patients had a positive serum antigen test. Analysis of the pair of monoclonal antibodies (2D1, 2E8) used in the capture ELISA for potential cross-reactivity in the detection of lipopolysaccharides of E. coli O157:H7 and Yersinia enterocolitica O9 showed specificity for Brucella lipopolysaccharide. This new approach to develop antigen-detection monoclonal antibodies against a T cell-independent polysaccharide antigen based on immunogenic protein conjugation may lead to the production of improved rapid point-of-care-deployable assays for the diagnosis of brucellosis and other infectious diseases.
Lemieux, C; St-Germain, G; Vincelette, J; Kaufman, L; de Repentigny, L
The Cand-Tec Candida detection system and enzyme immunoassay for serum mannan were retrospectively compared in a controlled collaborative evaluation of antigen detection in 32 patients with candidiasis proven by biopsy or culture from a normally sterile site and with sera drawn within 7 days of inclusion. With a threshold titer of 1/8, which excluded false-positive results in 17 hospitalized patients without candidiasis, sensitivities for all 32 patients with candidiasis were 44% for the Cand-Tec assay and 17% for the enzyme immunoassay. Both assays provided greater sensitivity when sera were drawn within 24 h of inclusion in the study and in the category of patients with invasive candidiasis (57% by Cand-Tec and 33% by enzyme immunoassay). The Cand-Tec assay gave false-positive results (titer, greater than or equal to 1/8) in 4 of 6 patients with transient candidemia, in 1 of 20 otherwise healthy patients with rheumatoid factor, and in 1 patient with a positive cryptococcal latex agglutination test. Three serum specimens from 3 of 32 patients with candidiasis contained rheumatoid factor and gave titers of greater than or equal to 1/8 by the Cand-Tec assay. Detection of serum mannan by enzyme immunoassay was less sensitive but more specific than the Cand-Tec Candida detection system for the diagnosis of invasive candidiasis. PMID:2179258
Rodríguez, Islay; Alvarez, Elvio L; Fernández, Carmen; Miranda, Alina
A recombinant-antigen enzyme immunoassay (EIA), BioSCREEN anti-Treponema pallidum, was compared favorably with the T. pallidum hemagglutination test, in the detection of specific antibodies in different groups of sera from patients with primary (n = 38), secondary (n = 10), early latent (n = 28) and congenital syphilis (n = 2), patients with leptospirosis ( n= 8), infectious mononucleosis (n = 7), hepatitis (n = 9), diabetes mellitus (n = 11), rheumatoid arthritis (n = 13), leprosy (n = 11), tuberculosis (n = 9), HIV/Aids ( n= 12), systemic lupus erythematosus (n = 4), rheumatic fever (n = 3), old-persons (n = 9), pregnant women (n = 29) and blood donors (n = 164). The coincidence between them was 95.1%. The sensitivity and specificity of the EIA were 93.3% and 95.5%, respectively. Fifteen serum specimens belonging to old-persons, pregnant women, blood donors, and patients with human leptospirosis, hepatitis, diabetes mellitus, tuberculosis and rheumatic fever gave false-positive results by Venereal Disease Research Laboratory and/or Rapid Plasma Reagin. The EIA can be used as alternative method for the serological confirmation of syphilis.
Leprosy is caused by the organism Mycobacterium leprae . The leprosy test involves injection of an antigen just under ... if your body has a current or recent leprosy infection. The injection site is labeled and examined ...
Palmer, Mitchell V.; Stafne, Molly R.; Bass, Kristin E.; Maggioli, Mayara F.; Thacker, Tyler C.; Linscott, Rick; Lawrence, John C.; Nelson, Jeffrey T.; Esfandiari, Javan; Greenwald, Rena; Lyashchenko, Konstantin P.
Several serological tests designed to detect antibodies to immunodominant Mycobacterium bovis antigens have recently emerged as ancillary tests for the detection of bovine tuberculosis in cattle, particularly when used after the injection of purified protein derivative (PPD) for skin testing, which significantly boosts M. bovis-specific antibody responses. The present findings demonstrate the onset and duration of boosted antibody responses after the injection of M. bovis PPD for the caudal fold test (CFT) and Mycobacterium avium and M. bovis PPDs for the comparative cervical test (CCT), administered in series in cattle experimentally infected with M. bovis. While skin tests boosted the responses to certain antigens (i.e., MPB83 and MPB70), they did not affect the responses to other antigens (e.g., ESAT-6, CFP10, MPB59, and MPB64). Administration of the CCT 105 days after the CFT resulted in an even greater secondary boost in antibody responses to MPB83 and MPB70 and to a proteinase K-digested whole-cell sonicate (WCS-PK) of M. bovis. Both IgM and IgG contributed to the initial boost in the MPB83/MPB70-specific antibody response after the CFT. The secondary boost after the CCT was primarily due to increased IgG levels. Also, the avidity of antibodies to MPB83 and MPB70 increased after the CCT in M. bovis-infected cattle. The avidity of antibodies to the WCS-PK antigens increased in the interval between the CFT and the CCT but did not increase further after the CCT. Together, these findings demonstrate that the administration of PPDs for skin tests results in additive enhancement (i.e., when the CFT and CCT are performed in series), both qualitative and quantitative, of MPB83/MPB70-specific antibody responses. PMID:25855555
Anamnart, Witthaya; Intapan, Pewpan Maleewong; Pattanawongsa, Attarat; Chamavit, Pennapa; Kaewsawat, Supreecha; Maleewong, Wanchai
Dispersion or dilution of stool by water from heavy rainfall may affect Strongyloides stercoralis free-living development producing infective filariform larvae (FL). This study examined effect of water dilution of stool on survival of S. stercoralis free-living development. One g of stool was prepared in water so that its soluble component was diluted sequentially from 1:2 to 1:480. Three dishes were used to compare FL production in three culture conditions: stool suspension, stool sediment deposited in soil, and isolated rhabditiform larvae (RhL) deposited in soil. The fourth dish was for developmental observation of RhL into free-living stages. Numerous FL were generated from undiluted or 1:2 diluted stool and stool sediment placed on soil. However, starting from dilution 1:5, FL production continuously decreased in both stool suspensions and stool sediments placed on soil. RhL isolated from stool dilutions placed on soil gave rise to few FL. Worm mating were seen at 24-30 hours in dilutions 1:20-1:120 only. Highest numbers of FL from indirect free-living cycle were 1/3 of those from control. FL production decreased as stool dilution increased, and reached zero production at 1:160 dilution. Rainfall may disperse or dilute stool so that nutritional supplement for S. stercoralis free-living development is insufficient.
Anamnart, Witthaya; Maleewong Intapan, Pewpan; Pattanawongsa, Attarat; Chamavit, Pennapa; Kaewsawat, Supreecha; Maleewong, Wanchai
Dispersion or dilution of stool by water from heavy rainfall may affect Strongyloides stercoralis free-living development producing infective filariform larvae (FL). This study examined effect of water dilution of stool on survival of S. stercoralis free-living development. One g of stool was prepared in water so that its soluble component was diluted sequentially from 1:2 to 1:480. Three dishes were used to compare FL production in three culture conditions: stool suspension, stool sediment deposited in soil, and isolated rhabditiform larvae (RhL) deposited in soil. The fourth dish was for developmental observation of RhL into free-living stages. Numerous FL were generated from undiluted or 1:2 diluted stool and stool sediment placed on soil. However, starting from dilution 1:5, FL production continuously decreased in both stool suspensions and stool sediments placed on soil. RhL isolated from stool dilutions placed on soil gave rise to few FL. Worm mating were seen at 24-30 hours in dilutions 1:20-1:120 only. Highest numbers of FL from indirect free-living cycle were 1/3 of those from control. FL production decreased as stool dilution increased, and reached zero production at 1:160 dilution. Rainfall may disperse or dilute stool so that nutritional supplement for S. stercoralis free-living development is insufficient. PMID:26035061
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Blanc, V; Mothes, A; Smetz, A; Timontin, I; Guardia, M D; Billiemaz, A; Dellamonica, J; Vassallo, M; Néri, D; Chadapaud, S; Toyer, A-L; Del Guidice, P; Fribourg, A; Léotard, S; Nicolle, I; Roger, P-M
Positive urinary antigen tests (UAT) for pneumococcal infection in community-acquired pneumonia (CAP) may lead to targeted antibiotic therapy. We report an audit aimed at defining the link between mortality and targeted therapy. We conducted a retrospective multicentre audit of patients with severe CAP for whom a UAT was positive for S. pneumoniae. Patients admitted from January 2010 to December 2013 to 8 medical centres (from A to H) were included. Co-morbidities were defined by the specific treatment administered before hospital care, or if the diagnosis was newly established during the hospital stay. We used the Pneumonia Severity Index (PSI) to assess disease severity. Only patients with PSI > 90 were included. Antibiotic treatments and the PSI were extracted from patients' charts. Amoxicillin had to be prescribed as a targeted antibiotic treatment or at the time of antibiotic reassessment. A total of 389 patients were included. The mean (±STD) PSI score was 128 ± 29; 38.9% of the patients had a class 5 PSI score. Intensive care was required for 36.6% of the patients. Amoxicillin was initially prescribed in 47 cases (12.1%) and in 34 cases after reassessment (8.7%). In logistic regression analysis, we found three parameters associated with mortality: being hospitalised in institution D, class 5 PSI score, and metastatic cancer. In contrast, three antibiotic regimens were protective factors, including targeted therapy: OR = 0.09, p < 0.001. In the context of severe CAP with positive UAT for S. pneumoniae, targeted therapy was associated with a reduction in mortality.
García, Amparo; Rosón, Beatriz; Pérez, José Luis; Verdaguer, Ricard; Dorca, Jordi; Carratalà, Jordi; Casanova, Aurora; Manresa, Frederic; Gudiol, Francesc
In a large number of cases, the etiology of community-acquired pneumonia (CAP) is not established. Some cases are probably caused by Streptococcus pneumoniae. Transthoracic needle aspiration (TNA) culture has a limited sensitivity which might be improved by antigen detection or gene amplification techniques. We evaluated the capacity of a PCR assay and a latex agglutination test to detect S. pneumoniae in samples obtained by TNA from 95 patients with moderate-to-severe CAP. Latex agglutination and PCR had sensitivities of 52.2 and 91.3%, specificities of 88.7 and 83.3%, positive predictive values of 62.3 and 65.6%, and negative predictive values of 83.3 and 96.5%, respectively, when culture techniques were used as the “gold standard.” When we considered expanded criteria for the diagnosis of pneumococcal pneumonia as a standard for our calculations, latex agglutination and PCR had sensitivities of 53.6 and 89.7%, specificities of 93.0 and 90.0%, positive predictive values of 78.9 and 81.3%, and negative predictive values of 80.3 and 94.7%, respectively. The additional diagnosis provided by the PCR assay compared to latex agglutination was 12.2% (95% confidence interval of the difference from 0.4 to 20.1%). PCR was more sensitive than TNA culture, particularly in patients who had received prior antibiotic therapy (83.3 versus 33.3%). Although PCR is a very sensitive and specific technique, it has not proved to be cost-effective in clinical practice. Conversely, latex agglutination is a fast and simple method whose results might have significant implications for initial antibiotic therapy. PMID:9986837
Choi, Kang-Seuk; Kye, Soo-Jeong; Jeon, Woo-Jin; Park, Mi-Ja; Kim, Saeromi; Seul, Hee-Jung; Kwon, Jun-Hun
A recombinant hemagglutinin-neuraminidase (rHN) protein from Newcastle disease virus (NDV) with hemagglutination (HA) activity was expressed in Spodoptera frugiperda cells using a baculovirus expression system. The rHN protein extracted from infected cells was used as an antigen in a hemagglutination inhibition (HI) test for the detection and titration of NDV-specific antibodies present in chicken sera. The rHN antigen produced high HA titers of 2(13) per 25 μL, which were similar to those of the NDV antigen produced using chicken eggs, and it remained stable without significant loss of the HA activity for at least 12 weeks at 4°C. The rHN-based HI assay specifically detected NDV antibodies, but not the sera of other avian pathogens, with a specificity and sensitivity of 100% and 98.0%, respectively, in known positive and negative chicken sera (n = 430). Compared with an NDV-based HI assay, the rHN-based HI assay had a relative sensitivity and specificity of 96.1% and 95.5%, respectively, when applied to field chicken sera. The HI titers of the rHN-based HI assay were highly correlated with those in an NDV-based HI assay (r = 0.927). Overall, these results indicate that rHN protein provides a useful alternative to NDV antigen in HI assays.
Webb, B J; Edwards, M S; Baker, C J
The usefulness of Phadebact streptococcus reagents for the detection of group B streptococcal antigen in cerebrospinal fluid was evaluated in 54 infants with meningitis and in 22 normal infants. Antigens was detected by slide coagglutination in 19 (82.6%) and by countercurrent immunoelectrophoresis in 20 (87.0%) of 23 cerebrospinal fluid specimens from infants with group B streptococcal meningitis at admission. After initiation of antimicrobial therapy, antigen could be detected in 11 of 19 (by slide coagglutination) and 7 of 18 (by countercurrent immunoelectrophoresis) cerebrospinal fluids. False-positive reactions were noted by slide coagglutination in one infant with S. bovis meningitis and one with group B streptococcal bacteremia without meningitis; none occurred with countercurrent immunoelectrophoresis. The commercial availiability, simplicity, sensitivity (82.6%), and specificity (96.4%) of the Phadebact slide coaggluatination test for detecting group B streptococcal antigen in cerebrospinal fluid suggest that it may be useful for the early and rapid diagnosis of group B streptococcal meningitis. PMID:6991524
Knopp, Stefanie; Corstjens, Paul L. A. M.; Koukounari, Artemis; Cercamondi, Colin I.; Ame, Shaali M.; Ali, Said M.; de Dood, Claudia J.; Mohammed, Khalfan A.; Utzinger, Jürg; Rollinson, David; van Dam, Govert J.
Background Elimination of schistosomiasis as a public health problem and interruption of transmission in selected areas are key goals of the World Health Organization for 2025. Conventional parasitological methods are insensitive for the detection of light-intensity infections. Techniques with high sensitivity and specificity are required for an accurate diagnosis in low-transmission settings and verification of elimination. We determined the accuracy of a urine-based up-converting phosphor-lateral flow circulating anodic antigen (UCP-LF CAA) assay for Schistosoma haematobium diagnosis in low-prevalence settings in Zanzibar, Tanzania. Methodology A total of 1,740 urine samples were collected in 2013 from children on Pemba Island, from schools where the S. haematobium prevalence was <2%, 2–5%, and 5–10%, based on a single urine filtration. On the day of collection, all samples were tested for microhematuria with reagent strips and for the presence of S. haematobium eggs with microscopy. Eight months later, 1.5 ml of urine from each of 1,200 samples stored at -20°C were analyzed by UCP-LF CAA assay, while urine filtration slides were subjected to quality control (QCUF). In the absence of a true ‘gold’ standard, the diagnostic performance was calculated using latent class analyses (LCA). Principal Findings The ‘empirical’ S. haematobium prevalence revealed by UCP-LF CAA, QCUF, and reagent strips was 14%, 5%, and 4%, respectively. LCA revealed a sensitivity of the UCP-LF CAA, QCUF, and reagent strips of 97% (95% confidence interval (CI): 91–100%), 86% (95% CI: 72–99%), and 67% (95% CI: 52–81%), respectively. Test specificities were consistently above 90%. Conclusions/Significance The UCP-LF CAA assay shows high sensitivity for the diagnosis of S. haematobium in low-endemicity settings. Empirically, it detects a considerably higher number of infections than microscopy. Hence, the UCP-LF CAA employed in combination with QCUF, is a promising tool for
Woods, V. Diane; Montgomery, Susanne B.; Herring, R. Patti; Gardner, Robert W.; Stokols, Daniel
BACKGROUND: Black American men continue to suffer disproportionately from epidemically higher rates of prostate cancer. We hypothesize that complex reasons for persistently higher death rates of prostate cancer in this group are steeped in social factors associated with health access. METHODS: We utilized data from the It's All About U prostate cancer prevention study among black men to investigate: 1) what social ecological factors were predictive of prostate-specific antigen (PSA) testing and digital rectal examinations (DRE); 2) if black men were aware of prostate cancer screening and, if screening was available, would they take the PSA and DRE? Quantitative cross-sectional data from a cohort of 276 black men with no diagnosis of prostate cancer were analyzed to identify characteristics, beliefs, practices and attitudes of this group toward prostate cancer screening. We created a social ecological model to examine which social factors (i.e., environmental, personal, person/environment interplay, black culture and institutional policy) were predictive of PSA and DRE, PSA only and DRE only. To reduce data and identify data patterns, factor analyses (tested for reliability by calculating Cronbach alpha scores) were performed. Variables were standardized with Z scores and analyzed with predictive analytic software technology (SPSS, version 12). A multivariate binary logistic regression was conducted to identify predictors of PSA and DRE. RESULTS: A significant predictor of both PSA and DRE was the physician's direct prostate cancer communication message (P<0.010). Significant correlations exist in PSA and DRE outcomes with a physician's engaging communication style (P<0.012), encouragement to screen (P<0.001) and sharing prostate cancer information (P<0.001); as was men understanding the serious risk of prostate cancer (P<0.001), culture (P<0.004), positive interaction with healthcare staff, significant other(s) and providers (P<0.001), and environmental dimensions
Castelain, M; Birnbaum, J; Castelain, P Y; Ducombs, G; Grosshans, E; Jelen, G; Lacroix, M; Meynadier, J; Mougeolle, J M; Lachapelle, J M
We performed patch tests with Dermatophagoides pteronyssinus (Dp) antigens from 2 different sources in 355 non-randomly selected patients with atopic dermatitis (AD) and 398 subjects of a control group. The study demonstrated that contact sensitization to mites occurred in an appreciable % of AD cases (20.8%), using commonly available assay products. The differences recorded between the 2 materials tested were related to the concentration of P1 antigen. Non-atopic patients rarely showed positive reactions to Dp (0.75%), when strict criteria for readings were applied and if 2 readings were performed. Patients with positive patch tests did not necessarily show positive immediate skin tests. It would be useful to carry out tests systematically in atopic patients, even if it is not yet known what modern treatment would be best for the patient. Laboratories still do not provide standardized house dust mite preparations--measuring and codifying their biological activity--for use in patch tests. It is to be hoped that the extension of this type of test will lead to the production of better test materials, in syringes with homogeneous dispersion and concentration.
Wasfy, M; Oyofo, B; Elgindy, A; Churilla, A
Transportation of clinical samples and long-term recoverability of pathogens are critical to epidemiological studies, particularly when conditions do not permit immediate processing. This study confirms that Cary-Blair medium (CB) is suitable for the preservation of Salmonella and Shigella isolates for more than 2 weeks at 25, 4, or -70 degrees C. Campylobacter jejuni was not recovered after 2 days of storage in CB at 25 degrees C when an inoculum of 12 x 10(8) cells per ml was used. Lower temperatures supported the recovery of this organism for 6 days. When individual pathogens were preserved with stools in CB and incubated at 25, 4, or -70 degrees C, the Salmonella and Shigella concentrations dropped from 12 x 10(8) cells to 1 x 10(3) or 1 x 10(4) cells per ml within 2 days and then remained stable for the rest of the observation period (15 days). C. jejuni survived preservation with stools for 5 to 9 days. The addition of blood and glycerol to CB improved the recoverability of all enteropathogens, particularly C. jejuni, which was consistently detected for 7 to 9 days at the different preservation temperatures used. When trypticase soy broth-glycerol (freezing medium), with or without blood, was used, there was little or no decrease in the Salmonella and Shigella concentrations during 2 weeks of preservation with stools at -70 degrees C. C. jejuni demonstrated a relatively sustained high concentration in Trypticase soy broth-glycerol with 5% blood.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7559972
Weiner, Zachary P; Crew, Rebecca M; Brandt, Kevin S; Ullmann, Amy J; Schriefer, Martin E; Molins, Claudia R; Gilmore, Robert D
Laboratory testing for the diagnosis of Lyme disease is performed primarily by serologic assays and is accurate for detection beyond the acute stage of the infection. Serodiagnostic assays to detect the early stages of infection, however, are limited in their sensitivity, and improvement is warranted. We analyzed a series of Borrelia burgdorferi proteins known to be induced within feeding ticks and/or during mammalian infection for their utility as serodiagnostic markers against a comprehensive panel of Lyme disease patient serum samples. The antigens were assayed for IgM and IgG reactivity in line immunoblots and separately by enzyme-linked immunosorbent assay (ELISA), with a focus on reactivity against early Lyme disease with erythema migrans (EM), early disseminated Lyme neuroborreliosis, and early Lyme carditis patient serum samples. By IgM immunoblotting, we found that recombinant proteins BBA65, BBA70, and BBA73 reacted with early Lyme EM samples at levels comparable to those of the OspC antigen used in the current IgM blotting criteria. Additionally, these proteins reacted with serum samples from patients with early neuroborreliosis and early carditis, suggesting value in detecting early stages of this disease progression. We also found serological reactivity against recombinant proteins BBA69 and BBA73 with early-Lyme-disease samples using IgG immunoblotting and ELISA. Significantly, some samples that had been scored negative by the Centers for Disease Control and Prevention-recommended 2-tiered testing algorithm demonstrated positive reactivity to one or more of the antigens by IgM/IgG immunoblot and ELISA. These results suggest that incorporating additional in vivo-expressed antigens into the current IgM/IgG immunoblotting tier in a recombinant protein platform assay may improve the performance of early-Lyme-disease serologic testing.
Wasfy, M; Oyofo, B; Elgindy, A; Churilla, A
Transportation of clinical samples and long-term recoverability of pathogens are critical to epidemiological studies, particularly when conditions do not permit immediate processing. This study confirms that Cary-Blair medium (CB) is suitable for the preservation of Salmonella and Shigella isolates for more than 2 weeks at 25, 4, or -70 degrees C. Campylobacter jejuni was not recovered after 2 days of storage in CB at 25 degrees C when an inoculum of 12 x 10(8) cells per ml was used. Lower temperatures supported the recovery of this organism for 6 days. When individual pathogens were preserved with stools in CB and incubated at 25, 4, or -70 degrees C, the Salmonella and Shigella concentrations dropped from 12 x 10(8) cells to 1 x 10(3) or 1 x 10(4) cells per ml within 2 days and then remained stable for the rest of the observation period (15 days). C. jejuni survived preservation with stools for 5 to 9 days. The addition of blood and glycerol to CB improved the recoverability of all enteropathogens, particularly C. jejuni, which was consistently detected for 7 to 9 days at the different preservation temperatures used. When trypticase soy broth-glycerol (freezing medium), with or without blood, was used, there was little or no decrease in the Salmonella and Shigella concentrations during 2 weeks of preservation with stools at -70 degrees C. C. jejuni demonstrated a relatively sustained high concentration in Trypticase soy broth-glycerol with 5% blood. The use of defibrinated, laked sheep blood as a long-term freezing medium supported the recovery of low concentrations of Salmonella and Shigella spp. (10(2) to 10(3) cells per ml) for more than 14 weeks. Recovery of C. jejuni was consistent for 7 weeks when an initial concentration of 10(6) cells per ml present in stools. Laked blood provided a simple, sterile, and inexpensive medium for the preservation of individual isolates and clinical samples.
Gillers, Sara; Atkinson, Christopher D.; Bartoo, Aaron C.; Mahalanabis, Madhumita; Boylan, Michael O.; Schwartz, John H.; Klapperich, Catherine; Singh, Satish K.
In this paper, we describe the design of a microfluidic sample preparation chip for human stool samples infected with Clostridium difficile. We established a polymerase chain reaction able to distinguish C. difficile in the presence of several other organisms found in the normal intestinal flora. A protocol for on-chip extraction of nucleic acids from clinical samples is described that can detect target DNA down to 5.0×10−3 ng of template. The assay and sample preparation chip were then validated using known positive and known negative clinical samples. The work presented has potential applications in both the developed and developing world. PMID:19505511
Allison, Rosalie; Lecky, Donna M.; Bull, Megan; Turner, Kim; Godbole, Gauri
Introduction. The National Institute for Health and Clinical Excellence (NICE) guidance recommends that dyspeptic patients are tested for Helicobacter pylori using a urea breath test, stool antigen test, or serology. Antibiotic resistance in H. pylori is globally increasing, but treatment in England is rarely guided by susceptibility testing or surveillance. Aims. To determine compliance of microbiology laboratories in England with NICE guidance and whether laboratories perform culture and antibiotic susceptibility testing (AST). Methods. In 2015, 170 accredited English microbiology laboratories were surveyed, by email. Results. 121/170 (71%) laboratories responded; 96% provided H. pylori testing (78% on site). 94% provided H. pylori diagnosis using stool antigen; only four provided serology as their noninvasive test; 3/4 of these encouraged urea breath tests in their acute trusts. Only 22/94 (23%) of the laboratories performed H. pylori cultures from gastric biopsies on site; 9/22 performed AST, but the vast majority processed less than one specimen/week. Conclusions. Only five laboratories in England do not comply with NICE guidance; these will need the guidance reinforced. National surveillance needs to be implemented; culture-based AST would need to be centralised. Moving forward, detection of resistance in H. pylori from stool specimens using molecular methods (PCR) needs to be explored. PMID:27829836
Meurs, Lynn; Brienen, Eric; Mbow, Moustapha; Ochola, Elizabeth A.; Mboup, Souleymane; Karanja, Diana M. S.; Secor, W. Evan; Polman, Katja; van Lieshout, Lisette
Background 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. Methodology/Principal findings 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. Conclusions/Significance 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
García, Patricia C; Valenzuela, Natalia S; Rodríguez, M Victoria L; León, Eugenia C; Fernández, Heríberto J
Campylobacter jejuni is a common agent of enterocolitis in humans. Campylobacteriosis has been recognized as a zoonotic disease whose reservoir is the intestinal flora of poultry. The reposition of fluid and electrolytes is the recommended treatment, and antimicrobials are required only in severe and/or in prolonged disease. Given the emergence of resistance to drugs commonly used in the treatment of acute diarrhea, we studied the antimicrobial susceptibility of 73 strains of Campylobacter jejuni isolated from stool culture. The antimicrobials tested were: erythromycin, azithromycin, ampicillin and ciprofloxacin. Of the 73 strains tested by E-test, 32.4% were resistant to ciprofloxacin and 6.4% were resistant to ampicillin. Resistance to erythromycin and azithromycin was not detected. The surveillance of antimicrobial resistance of Campylobacter jejuni is important in the evaluation of empirically used antimicrobials in the treatment of bacterial enterocolitis.
Yamanaka, Atsushi; Moi, Meng Ling; Takasaki, Tomohiko; Kurane, Ichiro; Matsuda, Mami; Suzuki, Ryosuke; Konishi, Eiji
The introduction of a foreign virus into an area may cause an outbreak, as with the Zika virus (ZIKV) outbreak in the Americas. Preparedness for handling a viral outbreak involves the development of tests for the serodiagnosis of foreign virus infections. We previously established a gene-based technology to generate some flaviviral antigens useful for functional antibody assays. The technology utilizes a Japanese encephalitis virus subgenomic replicon to generate single-round infectious particles (SRIPs) that possess designed surface antigens. In the present study, we successfully expanded the capacity of SRIPs to four human-pathogenic mosquito-borne flaviviruses that could potentially be introduced from endemic to non-endemic countries: ZIKV, Sepik virus, Wesselsbron virus, and Usutu virus. Flavivirus-crossreactive monoclonal antibodies dose-dependently neutralized these SRIPs. ZIKV-SRIPs also produced antibody-dose-dependent neutralization curves equivalent to those shown by authentic ZIKV particles using sera from a Zika fever patient. The faithful expression of designed surface antigens on SRIPs will allow their use in neutralization tests to diagnose foreign flaviviral infections.
Ghasemikhah, Reza; Tabatabaiefar, Mohammad Amin; Shariatzadeh, Seyed Ali; Shahbazi, Abbas; Hazratian, Teymour
Strongyloides stercoralis is a nematode causing serious infections in immunocompromised patients. In chronically infected patients, the low parasitic content as well as the resemblance of the larvae to several other species make diagnosis basedonmorphology difficult. In the present study, a PCR-based method targeting the internal transcribed sequence 2 (ITS2) of the rDNA region was examined for the molecular detection of S. stercoralis infection from the stool samples. A total of 1800 patients were included. Three fresh stool samples were collected per patient, and S. stercoralis isolates were identified by the morphological method. A subset of isolates was later used in the PCR-based method as positive controls. Additionally, negative and no-template controls were included. Data analysis was accomplished using an x² test. Ap-value less than 0.05 was considered significant. In total, fivestool samples were found to be infected with S. stercoralis using the morphology method. PCR method detected S. stercoralis DNA target from all of the fiveDNA samples extracted from positive fecal samples.
Luo, Jieling; Wang, Jiapeng; Mathew, Anup S; Yau, Siu-Tung
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.
Background Gastrointestinal symptoms are not an uncommon manifestation of an influenza virus infection. In the present study, we aimed to investigate the presence of influenza viruses in the stools of adult patients consulting their general practitioner for uncomplicated acute diarrhea (AD) and the proportion of concurrent infections by enteric and influenza viruses. Method A case-control study was conducted from December 2010 to April 2011. Stool specimens were collected and tested for influenza viruses A (seasonal A/H3N2 and pandemic A/H1N1) and B, and for four enteric viruses (astrovirus, group A rotavirus, human enteric adenovirus, norovirus of genogroups I – NoVGI - and genogroup II - NoVGII). Results General practitioners enrolled 138 cases and 93 controls. Of the 138 stool specimens collected, 92 (66.7%) were positive for at least one of the four enteric viruses analysed and 10 (7.2%) tested positive for one influenza virus. None of these 10 influenza positive patients reported respiratory symptoms. In five influenza-positive patients (3.6%), we also detected one enteric virus, with 4 of them being positive for influenza B (2 had co-detection with NoVGI, 1 with NoVGII, and 1 with astrovirus). None of the 93 controls tested positive for one of the enteric and/or other influenza viruses we investigated. Conclusions In this study we showed that the simultaneous detection of influenza and enteric viruses is not a rare event. We have also reported, for the first time in general practice, the presence of seasonal and pandemic influenza viruses in the stools of adult patients consulting for uncomplicated AD. A simultaneous investigation of enteric and influenza viruses in patients complaining of gastrointestinal symptoms could be useful for future studies to better identify the agents responsible for AD. PMID:22709374
Medici, Maria Cristina; Martinelli, Monica; Ruggeri, Franco Maria; Abelli, Laura Anna; Bosco, Simona; Arcangeletti, Maria Cristina; Pinardi, Federica; De Conto, Flora; Calderaro, Adriana; Chezzi, Carlo; Dettori, Giuseppe
We developed a nested reverse transcription-PCR (nRT-PCR) for the detection of noroviruses in stools, using random primers for RT, the JV12/JV13 primer pair in the first round of nPCR, and a set of nine inner primers for the second, comprising the reverse sequences of primers SR46, SR48, SR50, and SR52, and five novel oligonucleotide sequences (113-1, 113-2, 115-1, 115-2, and 115-3). The specificity of the nRT-PCR was confirmed by testing 61 stools containing enteric viruses other than noroviruses. In comparative assays on either stools or RNA dilutions from two genogroup I and three genogroup II (GII) norovirus-positive samples, nRT-PCR was always at least as sensitive as RT-PCR and Southern hybridization. With some of the samples tested, the increase in sensitivity was 10-fold or higher. For GII viruses, the detectable range of nRT-PCR was estimated to be 8.4 x 10(4) to 2 RNA viral particles. When used on 85 stools from pediatric patients with acute gastroenteritis negative for viruses by electron microscopy and cell culture, the nRT-PCR detected norovirus in 19 samples (22.3%), while it failed to detect one reference RT-PCR-positive sample containing a Desert Shield strain. Sixteen of the 19 nRT-PCR-positive samples gave concordant results with reference RT-PCR and Southern hybridization, and all with sequence analysis. Partial sequencing of the polymerase region revealed that from January to April 2000 all GII strains except two (Rotterdam- and Leeds-like viruses) formed a tight cluster related to Hawaii virus. The nRT-PCR described could prove suitable for large epidemiological studies and for specialized clinical laboratories performing routine molecular testing.
Medici, Maria Cristina; Martinelli, Monica; Ruggeri, Franco Maria; Abelli, Laura Anna; Bosco, Simona; Arcangeletti, Maria Cristina; Pinardi, Federica; De Conto, Flora; Calderaro, Adriana; Chezzi, Carlo; Dettori, Giuseppe
We developed a nested reverse transcription-PCR (nRT-PCR) for the detection of noroviruses in stools, using random primers for RT, the JV12/JV13 primer pair in the first round of nPCR, and a set of nine inner primers for the second, comprising the reverse sequences of primers SR46, SR48, SR50, and SR52, and five novel oligonucleotide sequences (113-1, 113-2, 115-1, 115-2, and 115-3). The specificity of the nRT-PCR was confirmed by testing 61 stools containing enteric viruses other than noroviruses. In comparative assays on either stools or RNA dilutions from two genogroup I and three genogroup II (GII) norovirus-positive samples, nRT-PCR was always at least as sensitive as RT-PCR and Southern hybridization. With some of the samples tested, the increase in sensitivity was 10-fold or higher. For GII viruses, the detectable range of nRT-PCR was estimated to be 8.4 × 104 to 2 RNA viral particles. When used on 85 stools from pediatric patients with acute gastroenteritis negative for viruses by electron microscopy and cell culture, the nRT-PCR detected norovirus in 19 samples (22.3%), while it failed to detect one reference RT-PCR-positive sample containing a Desert Shield strain. Sixteen of the 19 nRT-PCR-positive samples gave concordant results with reference RT-PCR and Southern hybridization, and all with sequence analysis. Partial sequencing of the polymerase region revealed that from January to April 2000 all GII strains except two (Rotterdam- and Leeds-like viruses) formed a tight cluster related to Hawaii virus. The nRT-PCR described could prove suitable for large epidemiological studies and for specialized clinical laboratories performing routine molecular testing. PMID:16081909
Shome, Rajeswari; Krithiga, Natesan; Padmashree, B. S.; Sankarasubramanian, Jagadesan; Vishnu, Udayakumar S.; Sridhar, Jayavel; Gunasekaran, Paramasamy; Rahman, Habibur
Brucella abortus strain S99 is widely used for the preparation of colored, plain, recombinant and smooth lipopolysaccharide antigens for the preparation of Brucella diagnostic kits. The genome of this strain was sequenced and the length of the genome was 3,253,175 bp, with 57.2% G+C content. A total of 3,365 protein coding genes and 53 RNA genes were predicted. PMID:25146137
Shome, Rajeswari; Krithiga, Natesan; Padmashree, B S; Sankarasubramanian, Jagadesan; Vishnu, Udayakumar S; Sridhar, Jayavel; Gunasekaran, Paramasamy; Rajendhran, Jeyaprakash; Rahman, Habibur
Brucella abortus strain S99 is widely used for the preparation of colored, plain, recombinant and smooth lipopolysaccharide antigens for the preparation of Brucella diagnostic kits. The genome of this strain was sequenced and the length of the genome was 3,253,175 bp, with 57.2% G+C content. A total of 3,365 protein coding genes and 53 RNA genes were predicted.
Chesnais, Cédric B.; Vlaminck, Johnny; Kunyu-Shako, Billy; Pion, Sébastien D.; Awaca-Uvon, Naomi-Pitchouna; Weil, Gary J.; Mumba, Dieudonné; Boussinesq, Michel
The Alere Filariasis Test Strip (FTS) is a qualitative, point-of-care diagnostic tool that detects Wuchereria bancrofti circulating filarial antigen (CFA) in human blood, serum, or plasma. The Global Program to Eliminate Lymphatic Filariasis employs the FTS for mapping filariasis-endemic areas and assessing the success of elimination efforts. The objective of this study was to explore the relationship between the intensity of positive test lines obtained by FTS with CFA levels as determined by enzyme-linked immunosorbent assay (ELISA) with blood and plasma samples from 188 individuals who live in a filariasis-endemic area. The intensity of the FTS test line was assessed visually to provide a semiquantitative score (visual Filariasis Test Strip [vFTS]), and line intensity was measured with a portable spectrodensitometer (quantitative Filariasis Test Strip [qFTS]). These results were compared with antigen levels measured by ELISA in plasma from the same subjects. qFTS measurements were highly correlated with vFTS scores (ρ = 0.94; P < 0.001) and with plasma CFA levels (ρ = 0.91; P < 0.001). Thus, qFTS assessment is a convenient method for quantifying W. bancrofti CFA levels in human blood, which are correlated with adult worm burdens. This tool may be useful for assessing the impact of treatment on adult filarial worms in individuals and communities. PMID:27114288
Background There are challenges, when extracting bacterial DNA from specimens for molecular diagnostics, since fecal samples also contain DNA from human cells and many different substances derived from food, cell residues and medication that can inhibit downstream PCR. The purpose of the study was to evaluate two different DNA extraction methods in order to choose the most efficient method for studying intestinal bacterial diversity using Denaturing Gradient Gel Electrophoresis (DGGE). Findings In this study, a semi-automatic DNA extraction system (easyMag®, BioMérieux, Marcy I’Etoile, France) and a manual one (QIAamp DNA Stool Mini Kit, Qiagen, Hilden, Germany) were tested on stool samples collected from 3 patients with Inflammatory Bowel disease (IBD) and 5 healthy individuals. DNA extracts obtained by the QIAamp DNA Stool Mini Kit yield a higher amount of DNA compared to DNA extracts obtained by easyMag® from the same fecal samples. Furthermore, DNA extracts obtained using easyMag® seemed to contain inhibitory compounds, since in order to perform a successful PCR-analysis, the sample should be diluted at least 10 times. DGGE performed on PCR from DNA extracted by QIAamp DNA Stool Mini Kit DNA was very successful. Conclusion QIAamp DNA Stool Mini Kit DNA extracts are optimal for DGGE runs and this extraction method yields a higher amount of DNA compared to easyMag®. PMID:24447346
Estimates of stool output in diapers is not an appropriate guideline to use in determining fluid loss through stool. This study was conducted to determine the accuracy of the ability of the nurses (RNs) and patient care technicians (PCTs) to quantify stool volume in diapers. Size 3 diapers, baby food (green peas), and water were used to simulate combinations of stool and urine and differing degrees of water loss in stool. The results indicated that RNs' and PCTs' assessments of stool volume became less accurate as water loss increased. There were no differences in estimation accuracy between RN and PCTs, and years of experience for RNs or PCTs did not influence accuracy of estimation. It is important to use a holistic approach for determining hydration status in patients, particularly knowledge of signs and symptoms of dehydration.
Kesli, Recep; Polat, Hakki; Terzi, Yuksel; Kurtoglu, Muhammet Guzel; Uyar, Yavuz
Hepatitis C virus (HCV) is a global health care problem. Diagnosis of HCV infection is mainly based on the detection of anti-HCV antibodies as a screening test with serum samples. Recombinant immunoblot assays are used as supplemental tests and for the final detection and quantification of HCV RNA in confirmatory tests. In this study, we aimed to compare the HCV core antigen test with the HCV RNA assay for confirming anti-HCV results to determine whether the HCV core antigen test may be used as an alternative confirmatory test to the HCV RNA test and to assess the diagnostic values of the total HCV core antigen test by determining the diagnostic specificity and sensitivity rates compared with the HCV RNA test. Sera from a total of 212 treatment-naive patients were analyzed for anti-HCV and HCV core antigen both with the Abbott Architect test and with the molecular HCV RNA assay consisting of a reverse transcription-PCR method as a confirmatory test. The diagnostic sensitivity, specificity, and positive and negative predictive values of the HCV core antigen assay compared to the HCV RNA test were 96.3%, 100%, 100%, and 89.7%, respectively. The levels of HCV core antigen showed a good correlation with those from the HCV RNA quantification (r = 0.907). In conclusion, the Architect HCV antigen assay is highly specific, sensitive, reliable, easy to perform, reproducible, cost-effective, and applicable as a screening, supplemental, and preconfirmatory test for anti-HCV assays used in laboratory procedures for the diagnosis of hepatitis C virus infection.
March, J. B.; Gammack, C.; Nicholas, R.
Latex microspheres (diameter, 8 μm) were coated with anti-Mycoplasma capricolum subsp. capripneumoniae polyclonal immunoglobulin G (IgG) antiserum (anti-F38 biotype). The coated microspheres, when used in a latex agglutination test (LAT), detected M. capricolum subsp. capripneumoniae antigen in the serum of goats with contagious caprine pleuropneumoniae (CCPP). Beads also agglutinated strongly in the presence of purified M. capricolum subsp. capripneumoniae capsular polysaccharide (CPS). Preabsorption of CPS-specific antibodies prior to coating of the beads removed agglutinating activity in the presence of M. capricolum subsp. capripneumoniae, strongly suggesting that CPS is the likely soluble antigen recognized by the test. In addition, the specificity of the LAT exactly mirrored that of an M. capricolum subsp. capripneumoniae CPS-specific monoclonal antibody (WM25): of the 8 other mycoplasma species tested, agglutination was observed only with bovine serogroup 7. The LAT detected all 11 strains of M. capricolum subsp. capripneumoniae examined in this study, with a sensitivity level of 2 ng of CPS, or the equivalent of 1.7 × 104 CFU, in a reaction volume of 0.03 ml of serum. With field sera from goats with CCPP, the results of the LAT exhibited a 67% correlation with the results of the currently used complement fixation test (CFT), with the main discrepancy in diagnosis resulting from the increased sensitivity of the LAT compared to that of CFT. This antigen-detection LAT should prove particularly useful in identifying animals in the earliest stages of CCPP and combines sensitivity and low cost with ease of application in the field, without the need for any specialist training or equipment. PMID:11060083
Vandenplas, Yvan; Szajewska, Hania; Benninga, Marc; Di Lorenzo, Carlo; Dupont, Christophe; Faure, Christophe; Miqdadi, Mohamed; Osatakul, Seksit; Ribes-Konickx, Carmen; Saps, Miguel; Shamir, Raanan; Staiano, Annamaria
Introduction The Bristol Stool Form Scale (BSS) which consists of 7 photographs of different stool forms allows assessment of stool consistency (scale 1 for hard lumps to scale 7 for watery stools), in an objective manner in adults. The BSS is also sometimes used to characterise the stools of infants and young children. Despite its use, there is general agreement among paediatric gastroenterologists that the BSS is not adequate to be used in infants and young children who wear diapers; thus, a new scale specifically designed for this population is needed. Our aim is to develop a paediatric stool scale, the Brussels Infant and Toddler Stool Scale (‘BITSS’), and to evaluate the interobserver agreement of stool assessment with the BITSS between the patient's parent and healthcare providers (physicians and nurses). Methods and analysis This study has two phases. In the first phase, 11 key-opinion leaders in the field of paediatric gastroenterology representing different areas of the world selected seven coloured photographs of infants and/or young children wearing diapers to match the original descriptors of the BSS. The selected photographs were used to create a new scale in which the drawings of stools of the BSS were replaced by infant/toddlers stool photographs. In phase II, we aim at demonstrating that parents, nurses and primary healthcare physicians interpret the stool-pictures of the BITSS with a high degree of consensus and that the agreement is independent of whether it is a parent or a healthcare provider. Interobserver variability of stool assessment with the BITSS between the patient's parent and healthcare providers will be assessed. Ethics and dissemination The study will be approved by the Ethics Committee of the participating centres. The findings of this study will be submitted to a peer-reviewed journal. Abstracts will be submitted to national and international conferences. Trial registration number NCT02913950. PMID:28360250
Esona, Mathew D; McDonald, Sharla; Kamili, Shifaq; Kerin, Tara; Gautam, Rashi; Bowen, Michael D
Rotaviruses are a major cause of viral gastroenteritis in children. For accurate and sensitive detection of rotavirus RNA from stool samples by reverse transcription-polymerase chain reaction (RT-PCR), the extraction process must be robust. However, some extraction methods may not remove the strong RT-PCR inhibitors known to be present in stool samples. The objective of this study was to evaluate and compare the performance of six extraction methods used commonly for extraction of rotavirus RNA from stool, which have never been formally evaluated: the MagNA Pure Compact, KingFisher Flex and NucliSENS easyMAG instruments, the NucliSENS miniMAG semi-automated system, and two manual purification kits, the QIAamp Viral RNA kit and a modified RNaid kit. Using each method, total nucleic acid or RNA was extracted from eight rotavirus-positive stool samples with enzyme immunoassay optical density (EIA OD) values ranging from 0.176 to 3.098. Extracts prepared using the MagNA Pure Compact instrument yielded the most consistent results by qRT-PCR and conventional RT-PCR. When extracts prepared from a dilution series were extracted by the 6 methods and tested, rotavirus RNA was detected in all samples by qRT-PCR but by conventional RT-PCR testing, only the MagNA Pure Compact and KingFisher Flex extracts were positive in all cases. RT-PCR inhibitors were detected in extracts produced with the QIAamp Viral RNA Mini kit. The findings of this study should prove useful for selection of extraction methods to be incorporated into future rotavirus detection and genotyping protocols.
Lee, Jihoo; Kim, Young-Eun; Kim, Hak-Yong; Sinniah, Mangalam; Chong, Chom-Kyu; Song, Hyun-Ok
High levels of anti-dengue IgM or IgG can be detected using numerous rapid diagnostic tests (RDTs). However, the sensitivity and specificity of these tests are reduced by changes in envelope glycoprotein antigenicity that inevitably occur in limited expression systems. A novel RDT was designed to enhance diagnostic sensitivity. Dengue viruses cultured in animal cells were used as antigens to retain the native viral coat protein. Monoclonal antibodies (mAbs) were then developed, for the first time, against domain I of envelope glycoprotein (EDI). The anti-dengue EDI mAb was employed as a capturer, and EDII and EDIII, which are mainly involved in the induction of neutralizing antibodies in patients, were fully available to bind to anti-dengue IgM or IgG in patients. A one-way automatic blood separation device prevented reverse migration of plasma and maximize the capture of anti-dengue antibodies at the test lines. A clinical evaluation in the field proved that the novel RDT (sensitivities of 96.5% and 96.7% for anti-dengue IgM and IgG) is more effective in detecting anti-dengue antibodies than two major commercial tests (sensitivities of 54.8% and 82% for SD BIOLINE; 50.4% and 75.3% for PanBio). The innovative format of RDT can be applied to other infectious viral diseases. PMID:26655854
Saliki, J T; Berninger, M L; Torres, A; House, J A; Mebus, C A; Dubovi, E J
Gamma irradiation effectively inactivated gradient-purified rinderpest virus. Irradiated antigen and sera remained functional in enzyme-linked immunosorbent assays, virus neutralization tests, and indirect fluorescent-antibody tests. Irradiation, however, led to a dose-dependent decrease in reactivity, particularly significant (P < 0.05) when both reagents were irradiated. To avoid false-positive reactions, only one reagent (serum or antigen) may be irradiated. PMID:8432831
Abdolahi Khabisi, Samaneh; Sarkari, Bahador; Moshfe, Abdolali; Jalali, Sedigheh
Parasitological methods are not helpful for the diagnosis of fascioliasis in acute and invasive periods of the disease. Detection of coproantigens seems to be a suitable alternative approach in the diagnosis of fascioliasis. The present study aimed to develop a reliable antigen detection system, using monoclonal antibodies raised against excretory-secretory (ES) antigen of Fasciola hepatica, for the diagnosis of fascioliasis. Fasciola adult worms were collected from the bile ducts of infected animals. Species of the fluke was determined by polymerase chain reaction-restriction fragment length polymorphism (RFLP-PCR). ES antigen of F. hepatica was prepared. For production of monoclonal antibodies, mice were immunized with ES antigens of F. hepatica. Spleen cells from the immunized mice were fused with NS-1 myeloma cells, using polyethylene glycol. Hybridoma cells secreting specific antibody were expanded and cloned by limiting dilution. Moreover, polyclonal antibody was produced against F. hepatica ES antigen in rabbits. A capture enzyme-linked immunosorbent assay (ELISA) system, using produced monoclonal antibody, was designed and stool samples of infected animals along with control samples were tested by the system. The capture ELISA detected the coproantigen in 27 of 30 (90%) parasitologically confirmed fascioliasis cases, while 4 of 39 (10.25%) samples infected with other parasitic infections showed a positive reaction in this system. No positive reactivity was found with healthy control samples. Accordingly, sensitivity of 90% and specificity of 94.2% were obtained for the capture ELISA system. The results were compared with those obtained with commercial BIO-X ELISA, and a very good (kappa = 0.9) agreement was found between the commercial kit and the developed capture ELISA. Findings of this study showed that the produced monoclonal antibody has appropriate performance for the detection of Fasciola coproantigen in stool samples and can be appropriately
Petrof, Elaine O; Khoruts, Alexander
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 up-to-date principles of microbial ecology. We discuss 2 pathways in the development of this new therapeutic class: whole microbial communities separated from donor stool and an assembly of specific fecal microorganisms grown in vitro.
Sousa-Figueiredo, José Carlos; Betson, Martha; Kabatereine, Narcis B.; Stothard, J. Russell
Background The World Health Organization now recommends the provision of praziquantel treatment to preschool-aged children infected with schistosomiasis. For intestinal schistosomiasis the current operational field diagnostic standard is examination of a thick Kato-Katz smear by microscopy prepared from a single stool specimen, and although pragmatic, this methodology has well-known shortcomings. Here, as a potential alternative, the performance of the urine circulating cathodic antigen (CCA) dipstick test was assessed in terms of disease-mapping and point-of-care diagnosis for intestinal schistosomiasis in preschool-aged children. Our manuscript reports on findings at baseline and at the end of a one-year longitudinal treatment study. Methodology/Principal Findings A total of 925 children (mean age 2.8 years) were initially recruited from six lakeshore villages representative of high, moderate and low levels of disease transmission. At baseline, all children were tested for intestinal schistosomiasis by microscopic examination of duplicate Kato-Katz smears prepared from a single stool faecal, by antigen detection with the urine CCA dipstick test and by serology with a commercially available ELISA test (as ‘gold-standard’) that measures host antibody titres to soluble egg antigens. As a point-of-care diagnosis, the urine CCA dipstick test achieved sensitivity and specificity values ranging from 52.5–63.2% and 57.7–75.6%, respectively, with faecal microscopy achieving very high specificities (>87%) but sensitivities as low as 16.7% in the low transmission setting. Conclusion/Significance The urine CCA test was shown to be more effective than faecal microscopy especially in lower transmission settings. The diagnostic performance of this test was not significantly impacted by treatment history or co-infections with other intestinal helminths. PMID:23359826
Avram, G; Zavate, O; Combiescu, A A; Perşu, A; Ivan, A; Constantiniu, S; Pancu, V; Popovici, S; Boghean, T; Nicola, P
The rotaviral antigen was detected by a screening test using the ELISA-IC kit in 17.6% out of 415 children with acute gastroenteritis. The highest frequency (28.9%) was found in children hospitalized in pediatric services with a diagnosis of diarrhoeic disease associated to acute respiratory infection. The rotavirus infection incidence was about three times higher during the cold season than during summer (30.4% versus 10.5%). The 6-11 month age group was the most severely affected.
Pritt, Bobbi S; Patel, Robin; Kirn, Thomas J; Thomson, Richard B
Nucleic acid amplification tests (NAATs) have frequently been the standard diagnostic approach when specific infectious agents are sought in a clinic specimen. They can be applied for specific agents such as S. pyogenes, or commercial multiplex NAATs for detection of a variety of pathogens in gastrointestinal, bloodstream, and respiratory infections may be used. NAATs are both rapid and sensitive. For many years, S. pyogenes testing algorithms used a rapid and specific group A streptococcal antigen test to screen throat specimens, followed, in some clinical settings, by a throat culture for S. pyogenes to increase the sensitivity of its detection. Now S. pyogenes NAATs are being used with increasing frequency. Given their accuracy, rapidity, and ease of use, should they replace antigen detection and culture for the detection of bacterial pharyngitis? Bobbi Pritt and Robin Patel of the Mayo Clinic, where S. pyogenes NAATs have been used for well over a decade with great success, will explain the advantages of this approach, while Richard (Tom) Thomson and Tom Kirn of the NorthShore University HealthSystem will discuss their concerns about this approach to diagnosing bacterial pharyngitis.
Wall, Steven J.; Sullivan, Lauren
Trypanosoma vivax is one of the causative agents of Animal African Trypanosomosis in cattle, which is endemic in sub-Saharan Africa and transmitted primarily by the bite of the tsetse fly vector. The parasite can also be mechanically transmitted, and this has allowed its spread to South America. Diagnostics are limited for this parasite and in farm settings diagnosis is mainly symptom-based. We set out to identify, using a proteomic approach, candidate diagnostic antigens to develop into an easy to use pen-side lateral flow test device. Two related members the invariant surface glycoprotein family, TvY486_0045500 and TvY486_0019690, were selected. Segments of these antigens, lacking N-terminal signal peptides and C-terminal transmembrane domains, were expressed in E. coli. Both were developed into ELISA tests and one of them, TvY486_0045500, was developed into a lateral flow test prototype. The tests were all evaluated blind with 113 randomised serum samples, taken from 37 calves before and after infection with T. vivax or T. congolense. The TvY486_0045500 and TvY486_0019690 ELISA tests gave identical sensitivity and specificity values for T. vivax infection of 94.5% (95% CI, 86.5% to 98.5%) and 88.0% (95% CI, 75.7% to 95.5%), respectively, and the TvY486_0045500 lateral flow test prototype a sensitivity and specificity of 92.0% (95% CI, 83.4% to 97.0%) and 89.8% (95% CI, 77.8% to 96.6%), respectively. These data suggest that recombinant TvY486_0045500 shows promise for the development of a pen-side lateral flow test for the diagnosis of T. vivax animal African trypanosomosis. PMID:27606593
Germani, Y; Guesdon, J L; Phalente, L; Begaud, E; Moreau, J P
Two erythrocyte immunoassay techniques to detect the presence of Escherichia coli heat-labile enterotoxin (LTh) in stool supernatants and cell-free culture supernatants were compared. In the competitive assay, GM1 ganglioside was coated onto V-shaped-well microdilution plates and enterotoxin was coupled to sheep erythrocytes. As little as 0.8 ng of LTh per ml was detected by this method, which was based on the competition between the LTh of the test sample and the sensitized erythrocytes. The second assay made use of chimera antibody prepared by coupling polyclonal anti-LTh antibody to a monoclonal antibody specific for sheep erythrocytes. In this case, LTh, which was specifically bound to a GM1 ganglioside-coated plate, was detected by successively adding the chimera antibody and sheep erythrocytes. The limit of detection of the chimera antibody erythrocyte immunoassay was 0.2 ng/ml. Stool samples were collected from 167 infants hospitalized for diarrhea in the hospital of Noumea, New Caledonia. False-negative reactions due to proteases present in the stool samples were avoided by the addition of phenylmethylsulfonyl fluoride. Images PMID:3290242
Yang, Paul; Hash, Sara; Park, Katherine; Wong, Charlene; Doraisamy, Loganathan; Petterson, Jonas; Petti, Cathy A; Ward, Pamela M; Lee, Seung Heon; Menon, Suresh; She, Rosemary C
We evaluated the performance of an early prototype core molecular mirroring nuclear magnetic resonance detection platform (Mentor-100) to detect toxigenic Clostridium difficile from stool. This technology uses customized nanoparticles bound to target specific oligonucleotide probes that form binaries in the presence of nucleic acid from the target microorganism. Liquid patient stool specimens were seeded with C. difficile or other Clostridium species to determine the analytical sensitivity and specificity. Samples underwent nucleic acid extraction and target amplification with probes conjugated with iron nanoparticles. Signal from nuclear magnetic resonance spin-spin relaxation time was measured to detect the presence or absence of toxigenic C. difficile. The limit of detection was <180 colony forming units per reaction of toxigenic C. difficile. No cross-reactivity was observed with nontoxigenic C. difficile, Clostridium sordellii, Clostridium perfringens, Bacillus subtilis, or Paenibacillus polymyxa at 10(8) colony forming units/mL. Correlation studies using frozen stool samples yielded a sensitivity of 88.4% (61 of 69) and a specificity of 87.0% (40 of 46) as compared with a commercial PCR assay for C. difficile. The area under the curve in the receiver operating characteristic curve analysis was 0.922. The prototype molecular mirroring platform showed promising performance for pathogen detection from clinical specimens. The platform design has the potential to offer a novel, low-cost alternative to currently available nucleic acid-based tests.
Medici, Maria Cristina; Tummolo, Fabio; Albonetti, Valeria; Pinardi, Federica; Ferraglia, Francesca; Chezzi, Carlo; Arcangeletti, Maria Cristina; De Conto, Flora; Calderaro, Adriana
A novel molecular assay, TRCRtest NV-W, based on a transcription-reverse transcription concerted reaction (TRC) for isothermal amplification and real-time detection of norovirus in stools was assessed and compared with an RT-nPCR. Archived stools positive for either different types or variants of norovirus genogroups I and II or other enteric viruses were used to assess the sensitivity and specificity of the novel assay. The TRC assay was 100% specific since it detected all the noroviruses tested and it did not display cross reactivity with other enteric viruses. When screening a collection of 387 stools with the TRC and RT-nPCR assays, the TRC displayed concordance, sensitivity, specificity, positive and negative predictive values of 96.6%, 81%, 99.7%, 98.1%, and 96.3%, respectively, after retesting the negative specimens. Additional PCRs and/or sequencing, used to understand inconsistent results between TRC and RT-nPCR, confirmed all positive results and did not reveal nucleotide variations in the TRC probe and primers binding sites. The TRC assay may be a rapid and ease of use tool for the detection of noroviruses in clinical virology laboratories even in the face of rapidly evolving noroviruses.
Mokhtari, W; Nsaibia, S; Gharbi, A; Aouni, M
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.
Mwinzi, Pauline N M; Kittur, Nupur; Ochola, Elizabeth; Cooper, Philip J; Campbell, Carl H; King, Charles H; Colley, Daniel G
Studies of the urine-based point-of-contact cathodic circulating antigen test (POC-CCA) in Schistosoma mansoni-endemic settings in Africa indicate it has good sensitivity in detecting infections, but in areas of low prevalence, the POC-CCA can be positive for persons who are egg-negative by Kato-Katz stool assays. We examined the POC-CCA assay for: (a) batch-to-batch stability; (b) intra-reader and inter-reader variability; (c) day-to-day variability compared to Kato-Katz stool assays, and (d) to see if praziquantel (PZQ) treatment converted Kato-Katz-negative/POC-CCA positive individuals to POC-CCA negativity. We found essentially no batch-to-batch variation, negligible intra-reader variability (2%), and substantial agreement for inter-reader reliability. Some day-to-day variation was observed over 5 days of urine collection, but less than the variation in Kato-Katz stool assays over 3 days. To evaluate the effect of treatment on Kato-Katz(-)/POC-CCA(+) children, 149 children in an area of 10-15% prevalence who were Kato-Katz(-) based on 3 stool samples but POC-CCA(+) were enrolled. Seven days after treatment (PZQ 40 mg/kg) samples were again collected and tested. Almost half (47%) POC-CCA positive children turned negative. Those still POC-CCA positive received a second treatment, and 34% of them turned POC-CCA negative upon this second treatment. Most who remained POC-CCA positive shifted each time to a "lesser" POC-CCA "level of positivity." The data suggest that most Kato-Katz-negative/POC-CCA positive individuals harbor low-intensity infections, and each treatment kills all or some of their adult worms. The data also suggest that when evaluated by a more sensitive assay, the effective cure rates for PZQ are significantly less than those inferred from fecal testing. These findings have public health significance for the mapping and monitoring of Schistosoma infections and in planning the transition from schistosomiasis morbidity control to elimination of
Mwinzi, Pauline N. M.; Kittur, Nupur; Ochola, Elizabeth; Cooper, Philip J.; Campbell, Carl H.; King, Charles H.; Colley, Daniel G.
Studies of the urine-based point-of-contact cathodic circulating antigen test (POC-CCA) in Schistosoma mansoni-endemic settings in Africa indicate it has good sensitivity in detecting infections, but in areas of low prevalence, the POC-CCA can be positive for persons who are egg-negative by Kato-Katz stool assays. We examined the POC-CCA assay for: (a) batch-to-batch stability; (b) intra-reader and inter-reader variability; (c) day-to-day variability compared to Kato-Katz stool assays, and (d) to see if praziquantel (PZQ) treatment converted Kato-Katz-negative/POC-CCA positive individuals to POC-CCA negativity. We found essentially no batch-to-batch variation, negligible intra-reader variability (2%), and substantial agreement for inter-reader reliability. Some day-to-day variation was observed over 5 days of urine collection, but less than the variation in Kato-Katz stool assays over 3 days. To evaluate the effect of treatment on Kato-Katz(−)/POC-CCA(+) children, 149 children in an area of 10–15% prevalence who were Kato-Katz(−) based on 3 stool samples but POC-CCA(+) were enrolled. Seven days after treatment (PZQ 40 mg/kg) samples were again collected and tested. Almost half (47%) POC-CCA positive children turned negative. Those still POC-CCA positive received a second treatment, and 34% of them turned POC-CCA negative upon this second treatment. Most who remained POC-CCA positive shifted each time to a “lesser” POC-CCA “level of positivity.” The data suggest that most Kato-Katz-negative/POC-CCA positive individuals harbor low-intensity infections, and each treatment kills all or some of their adult worms. The data also suggest that when evaluated by a more sensitive assay, the effective cure rates for PZQ are significantly less than those inferred from fecal testing. These findings have public health significance for the mapping and monitoring of Schistosoma infections and in planning the transition from schistosomiasis morbidity control to
Rickard, L G
A microenzyme-linked immunosorbent assay (dot-ELISA) was developed to detect serum antibodies against Fasciola hepatica antigens in llamas. Sera from five F. hepatica-infected and 11 non-infected llamas were used in initial test development. Nitrocellulose filter disks containing F. hepatica excretory-secretory product were placed in 96-well microtiter plates, washed, blocked with Tween-20, then incubated with four-fold serial dilutions of llama sera. After incubation with rabbit anti-llama IgG followed by peroxidase-conjugated goat anti-rabbit IgG, addition of precipitable substrate resulted in purple dots on white background (positives) easily read by eye. The technique was further evaluated at titers of 1:512 using an additional six known positive and eight known negative llamas. Test results showed 6/6 known positive as positive and 8/8 known negative as negative. Sera were collected, at approximately weekly intervals, from three llamas experimentally infected with F. hepatica. The dot-ELISA detected antibodies to F. hepatica as early as the second week post-infection in all llamas. In a serologic survey of 256 llamas from an F. hepatica endemic area, the dot-ELISA detected antigen-specific serum antibodies to F. hepatica in 42 (16%) of the llamas. Although no difference was noted in antibody prevalence between sexes, prevalence increased in llamas over 6 months of age.
Nazé, Florence; Francart, Aurélie; Lamoral, Sophie; De Craeye, Stéphane; Kalai, Michael
A generic two-step lyssavirus real-time reverse transcriptase polymerase chain reaction (qRT-PCR), based on a nested PCR strategy, was validated for the detection of different lyssavirus species. Primers with 17 to 30% of degenerate bases were used in both consecutive steps. The assay could accurately detect RABV, LBV, MOKV, DUVV, EBLV-1, EBLV-2, and ABLV. In silico sequence alignment showed a functional match with the remaining lyssavirus species. The diagnostic specificity was 100% and the sensitivity proved to be superior to that of the fluorescent antigen test. The limit of detection was ≤1 50% tissue culture infectious dose. The related vesicular stomatitis virus was not recognized, confirming the selectivity for lyssaviruses. The assay was applied to follow the evolution of rabies virus infection in the brain of mice from 0 to 10 days after intranasal inoculation. The obtained RNA curve corresponded well with the curves obtained by a one-step monospecific RABV-qRT-PCR, the fluorescent antigen test, and virus titration. Despite the presence of degenerate bases, the assay proved to be highly sensitive, specific, and reproducible. PMID:24822188
Stanton, B; Silimperi, D R; Khatun, K; Kay, B; Ahmed, S; Khatun, J; Alam, K
Few data exist in Bangladesh on longitudinal, community-based studies of bacterial or parasitic pathogens identified in routine and diarrhoeal stools of urban dwelling children. We undertook the following study on 343 children of age less than 6 years who resided in one of 51 slum settings in Dhaka, Bangladesh, between October 1984 and February 1986. Specimens from diarrhoeal episodes and from routine stools obtained at 3-monthly intervals were examined for parasites, rotavirus and pathogenic bacteria. Parasites were isolated from 509 (51%) of the 1006 routine stools and from 95 (42%) of the 225 diarrhoeal stools. Isolation rates steadily increased with age. Ascaris lumbricoides and Trichuris trichiura accounted for approximately 80% of all parasitic isolates in routine and diarrhoeal stools. Giardia lamblia was isolated from 11% diarrhoeal stools. Entamoeba histolytica was an uncommon isolate (less than 1%). Bacterial pathogens were identified in 55 (24%) of the diarrhoeal stools but were identified in only 164 (16%) of the 1028 routine stools examined (P less than 0.01). Toxigenic Escherichia coli, Shigellae and Campylobacter were the most frequent isolates from diarrhoeal and routine specimens. This pathogen profile appears to be more in keeping with that from urban settings in other developing countries than from rural Bangladesh, suggesting that extrapolations from rural-based data should not be made for urban settings.
This study sought to: evaluate the ability of children to reliably use a modified Bristol Stool Form Scale for Children (mBSFS-C), evaluate criterion-related validity of the mBSFS-C, and identify the lower age limit for mBSFS-C use. The mBSFS-C comprises 5 stool form types described and depicted in ...
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...
Jayaraman, T; Prabhakaran, V; Babu, P; Raghava, M Venkata; Rajshekhar, V; Dorny, P; Muliyil, J; Oommen, A
We evaluated the exposure of a community in Vellore district of south India to Taenia solium infection and its relationship to the prevalence of neurocysticercosis (NCC) causing active epilepsy. Seroprevalence of Taenia cysticercus antigens and antibodies were determined in 1064 randomly chosen asymptomatic individuals, antibodies to T. solium ova in 197 selected sera, and prevalence of taeniasis by a coproantigen test in 729 stool samples. The prevalence of NCC causing active epilepsy in Vellore district was determined in a population of 50 617. Coproantigens were detected in 0.8% (6 samples), Taenia cysticercus antigens in 4.5% (48 sera) and cysticercus IgG antibodies in 15.9% (169 sera) of the population. Cysticercus antibodies were directed against relatively low molecular weight cyst glycoprotein antigens in 14.9% (158 sera) of the population. IgG antibodies to Taenia ova were found in 81 (41.1%) of the selected samples. Prevalence of NCC causing active epilepsy was 1.3 per 1000 population. These results show high exposure of the population to the parasite and a relatively high prevalence of active infections (4.5% antigen positives) but a low prevalence of NCC causing active epilepsy (0.13%). These findings may indicate that the population is protected against developing neurocysticercosis. IgG antibodies directed against Taenia ova and low molecular weight cyst antigens may contribute to protection.
braziliensis (MHOM/BR/75/M2903), L. chagasi (MJOM/BR/82/BA-2,C 1), L. donovani (MHOMiEt/67iHU3), Leishmania guyanensis (MIHOMJBR/75/M4147), L. infantum (IPT-1...comparative test to a variety of other recombinant Leishmania antigens including L. chagasi hsp70, L. braziliensis hsp83/90, L. braziliensis eIF4A, L...34 4. AD CONTRACT NO: DAMD17-92-C-2082 EC•£ 2 j 994 ’i, L TITLE: DIAGNOSTIC ANTIGENS OF LEISHMANIA L PRINCIPAL INVESTIGATOR: Steven G. Reed, Ph.D
Breda, Giovanni; Almeida, Bernado; Carstensen, Suzana; Bonfim, Carmem M; Nogueira, Meri B; Vidal, Luine R; Almeida, Sergio M; Raboni, Sonia M
Aim: Cytomegalovirus (CMV) infection is one of the most common complications in patients submitted to hematopoietic stem cell transplant (HSCT). Pre-emptive therapy has been indicated in patients with laboratory evidence of CMV replication. The aims of this study were to compare real-time PCR or pp65 antigen assay methodologies to detect CMV replication in HSCT patients, define a viral load threshold for initiation of pre-emptive therapy, and assess the feasibility of its implementation in hospitals of countries with low and middle income. Material and methods: Human CMV detection by real-time PCR and pp65 antigen assay was carried out in blood and plasma samples of HSCT patients collected weekly during 3 months. Pre-emptive therapy was based on CMV antigenemia results. Results: Twenty-one patients were monitored with a total of 227 samples collected; 13 (62%) patients were children. A poor correlation was observed between qualitative results, though quantitative results showed statistically significant difference, with higher viral loads detected in patients with positive antigenemia. Compared to a positive antigenemia, a cutoff value of 1067.5 copies/ml, 3.03 log10/ml, for viral load was obtained with 100% sensitivity and 71% specificity. Conclusion: CMV real-time PCR in whole blood was suitable for monitoring HSCT patients. However, its high cost is a limiting factor, and it could be used to monitor selected patients, those with prolonged leukopenia and underweight children, and subsequently switched to pp65 antigen test. Further studies involving larger numbers of patients should be performed to confirm this statement. PMID:24188241
Engel, M F; van Velzen, M; Hoepelman, A I M; Thijsen, S; Oosterheert, J J
A positive pneumococcal urinary antigen test (PUAT) for Streptococcus pneumoniae allows an early switch from empiric to targeted treatment in hospitalised community-acquired pneumonia (CAP) patients. The economic and treatment consequences of this widespread implemented test are, however, unknown. We retrospectively evaluated all tests performed since its introduction in two teaching hospitals. Data on patient characteristics, treatment, admission and outcome were retrieved from the electronic patient files. Test benefits were expressed as the number of days that targeted therapy (i.e. penicillin) was administered to hospitalised CAP patients due to a positive PUAT. This calculation was based on the timing of the PUAT and the initiation of targeted therapy. Subsequently, we performed two direct cost analyses from a hospital perspective, first including tests performed for CAP only, and second including costs of all (excessive) tests. Between 2005 and 2012, 3,479 PUATs were performed, of which 1,907 (55 %) were for CAP. A total of 1,638 PUATs (86 %) were negative and 269 (14 %) were positive. Fifty-two (19 %) positive tests were excluded. In 75 (35 %) of the 217 remaining positive tests, a positive PUAT led to targeted treatment during 293 cumulative admission days. Testing costs for CAP only were €131 per targeted treatment day. These costs were €257 if local protocol dictated PUAT use for all CAP cases, as opposed to €72 if the test was reserved for severe cases only. When including all tests, PUAT costs were €254 per targeted treatment day. Therefore, improving the selective use of the PUAT in hospitalised CAP patients may lead to increased (cost-)efficiency.
Martinez, Mitchell; Bhattacharya, Sanjoy K.; Abreu, Maria T.
Intake of saturated fat is a risk factor for ulcerative colitis (UC) and colon cancer. Changes in the microbiota have been implicated in the development of UC and colon cancer. The host and the microbiota generate metabolites that may contribute to or reflect disease pathogenesis. We used lipid class specific quantitative mass spectrometry to assess the phospholipid (PL) profile (phosphatidylcholine [PC], phosphatidylethanolamine [PE], phosphatidylinositol [PI], phosphatidylserine [PS]) of stool from mice fed a high fat (HFD) or control diet with or without induction of colitis-associated tumors using azoxymethane and dextran sodium sulfate. The microbiota was assessed using qPCR for several bacterial groups. Colitis-associated tumors were associated with reduced bulk PI and PE levels in control diet fed mice compared to untreated mice. Significant decreases in the relative quantities of several PC species were found in colitis-associated tumor bearing mice fed either diet. Statistical analysis of the PL profile revealed distinct clustering by treatment group. Partial least squares regression analysis found that the relative quantities of the PS class profile best predicted bacterial abundance of Clostridium leptum and Prevotella groups. Abundance of selected PL species correlated with bacterial group quantities. Thus, we have described that a HFD and colitis-associated tumors are associated with changes in phospholipids and may reflect host-microbial interactions and disease states. PMID:25469718
Antunes, Danielle Mota Fontes; da Costa, Janilda Pacheco; Campos, Sylvia Maria Nicolau; Paschoal, Patrícia Olaya; Garrido, Valéria; Siqueira, Munique; Teixeira, Gerlinde Agate Platais Brasil; Cardoso, Gilberto Perez
The inappropriate immune response to foods, such as peanut, wheat and milk may be the basis in the pathogenesis of enteropathies like coeliac and Crohn disease, which present small intestinal malabsorption. A number of recent studies have utilized d-xylose absorption as an investigative tool to study small intestinal function in a variety of clinical settings. Thus, the aim of this experimental study was to evaluate the intestinal absorption of d-xylose in an antigen-specific gut inflammatory reaction rat model. Animals of the experimental group were inoculated with peanut protein extract before their exposure to a challenge diet containing exclusively peanut seeds to induce the gut inflammatory reaction caused by peanut allergy. Our results show that systemic inoculation with peanut protein extract renders significantly higher antibody titres (5.085 ± 0.126 units) (P < 0.0001) than control rats (0.905 ± 0.053 units) and that the antibody titres correlate positively to an inflammatory alteration of the gut morphology (P < 0.0001). Animals pertaining to the experimental group showed an intestinal absorption of d-xylose lower than control rats (P < 0.0001). We also observed that d-xylose absorption correlates negatively with IgG titres and positively with morphometric parameters (Pearson correlation). In conclusion, the use of serum d-xylose test was useful to identify the presence of small intestinal malabsorption in our antigen specific gut inflammatory reaction rat model. PMID:19335552
Kattenberg, Johanna H.; Tahita, Christian M.; Versteeg, Inge A. J.; Tinto, Halidou; Traoré/Coulibaly, Maminata; D'Alessandro, Umberto; Schallig, Henk D. F. H.; Mens, Petra F.
Rapid diagnostics tests (RDTs) detect malaria specific antigen(s) in the circulation, even when parasites are sequestered in the placenta and not visible by microscopy. However, research on their diagnostic accuracy during pregnancy is limited. Pregnant women (n = 418) were screened for malaria during routine antenatal care by using two RDTs that detect histidine-rich protein 2 (HRP2) or Plasmodium lactate dehydrogenase, and enzyme-linked immunosorbent assays with antibodies that detect dihydrofolate reductase–thymidylate synthase or heme-detoxification protein, and compared with real-time polymerase chain reaction (RT-PCR) and microscopy for evaluation of their diagnostic accuracy. Prevalence of malaria infection was high (53% by PCR). The RT-PCR and the HRP2 RDT detected most cases of malaria during pregnancy, whereas microscopy, the Plasmodium lactate dehydrogenase RDT, and enzyme-linked immunosorbent assays for dihydrofolate reductase–thymidylate synthase and heme-detoxification protein antibodies did not detect several low-density infections. Therefore, the HRP2 RDT could be a useful tool in high-transmission areas for diagnosis of malaria in asymptomatic pregnant women. PMID:22859362
Cedzynski, M; Knirel YuA; Amano, K I; Swierzko, A S; Paramonov, N A; Senchenkova, S N; Kaca, W
Based on monosaccharide analysis and 1H- and 13C-NMR spectroscopy, the following structure of the O-specific polysaccharide chain of Proteus vulgaris OX2 lipopolysaccharide (LPS), which defines the O2 specificity of Proteus, was established: [formula: see text] where L-QuiNAc is N-acetyl-L-quinovosamine (2-acetamido-2,6-dideoxy-L-glucose). Various strains of P. vulgaris OX2 used in the Weil-Felix test for serodiagnosis of rickettsiosis (spotted fevers, except for Rocky Mountain spotted fever) were shown to produce LPS with the same O-specific polysaccharide, which differs structurally and serologically from LPS of P. vulgaris OX19 used as antigen for serodiagnosis of typhus and Rocky Mountain spotted fever. O-Acetyl groups present in the polysaccharide are not important for manifesting the immunospecificity. ELISA confirmed that the epitope responsible for the cross-reactivity between sera from patients with Japanese spotted fever and P. vulgaris OX2 cells is located on the P. vulgaris LPS. At the same time, no cross-reaction was observed between rabbit anti-P. vulgaris OX2 antibodies and the spotted fever group (SFG) rickettsial cells. Therefore, human anti-SFG rickettsial antibodies and rabbit anti-P. vulgaris OX2 antibodies may bind to distinct epitopes on P. vulgaris OX2 LPS, and no epitope recognized by rabbit anti-P. vulgaris OX2 antibodies is present on the LPS or any other surface antigen of SFG rickettsiae.
Clarke, P Ryan; Edwards, William H; Hennager, Steven G; Block, Jean F; Yates, Angela M; Ebel, Eric; Knopp, Douglas J; Fuentes-Sanchez, Antonio; Jennings-Gaines, Jessica; Kientz, Rebecca L; Simunich, Marilyn
Brucellosis (caused by the bacterium Brucella abortus) is a zoonotic disease endemic in wild elk (Cervus canadensis) of the Greater Yellowstone Ecosystem, US. Because livestock and humans working with elk or livestock are at risk, validated tests to detect the B. abortus antibody in elk are needed. Using the κ-statistic, we evaluated the buffered, acidified plate antigen (BAPA) assay for agreement with the results of the four serologic tests (card test [card], complement fixation test [CF], rivanol precipitation plate agglutination test [RIV], standard plate agglutination test [SPT]) that are approved by the US Department of Agriculture for the detection of the B. abortus antibody in elk. From 2006 to 2010, serum samples collected from elk within B. abortus-endemic areas (n = 604) and nonendemic areas (n = 707) and from elk culture-positive for B. abortus (n = 36) were split and blind tested by four elk serum diagnostic laboratories. κ-Values showed a high degree of agreement for the card (0.876), RIV (0.84), and CF (0.774) test pairings and moderate agreement for the SPT (0.578). Sensitivities for the BAPA, card, RIV, CF, and SPT were 0.859, 0.839, 0.899, 1.00, and 0.813, whereas specificities were 0.986, 0.993, 0.986, 0.98, and 0.968, respectively. The positive predictive values and the negative predictive values were calculated for 2.6%, 8.8%, and 16.2% prevalence levels. These findings suggest the BAPA test is a suitable screening test for the B. abortus antibodies in elk.
Elbadawi, Lina I; Haupt, Thomas; Reisdorf, Erik; Danz, Tonya; Davis, Jeffrey P
On March 25, 2015, the Wisconsin Division of Public Health was notified of a possible respiratory syncytial virus (RSV) infection outbreak among infants hospitalized in a neonatal intensive care unit (NICU). On March 23, the index patient (neonate A), aged 3 days, had feeding intolerance and apnea. A nasopharyngeal swab specimen collected from neonate A was tested using a single-manufacturer rapid RSV antigen detection test (RRADT) at the hospital laboratory; the result was positive. The following day, because of concern about the possibility of more widespread RSV infection, RRADT was used to test nasopharyngeal swab specimens from neonate B, aged 1 month, who had resided in a different hospital room in the NICU and had developed an increased oxygen requirement, apnea, and poor feeding that day, as well as from two asymptomatic neonates who were hospitalized in the same room with neonate A; all three were positive. Later that day, nasopharyngeal swab specimens from the remaining 16 asymptomatic NICU patients were tested using the same RRADT; seven tests were positive, making a total of 11 positives. All 20 RRADTs were performed at the hospital laboratory.
Horita, Nobuyuki; Miyazawa, Naoki; Kojima, Ryota; Kimura, Naoko; Inoue, Miyo; Ishigatsubo, Yoshiaki; Kaneko, Takeshi
Studies on the sensitivity and specificity of the Binax Now Streptococcus pneumonia urinary antigen test (index test) show considerable variance of results. Those written in English provided sufficient original data to evaluate the sensitivity and specificity of the index test using unconcentrated urine to identify S. pneumoniae infection in adults with pneumonia. Reference tests were conducted with at least one culture and/or smear. We estimated sensitivity and two specificities. One was the specificity evaluated using only patients with pneumonia of identified other aetiologies ('specificity (other)'). The other was the specificity evaluated based on both patients with pneumonia of unknown aetiology and those with pneumonia of other aetiologies ('specificity (unknown and other)') using a fixed model for meta-analysis. We found 10 articles involving 2315 patients. The analysis of 10 studies involving 399 patients yielded a pooled sensitivity of 0.75 (95% confidence interval: 0.71-0.79) without heterogeneity or publication bias. The analysis of six studies involving 258 patients yielded a pooled specificity (other) of 0.95 (95% confidence interval: 0.92-0.98) without no heterogeneity or publication bias. We attempted to conduct a meta-analysis with the 10 studies involving 1916 patients to estimate specificity (unknown and other), but it remained unclear due to moderate heterogeneity and possible publication bias. In our meta-analysis, sensitivity of the index test was moderate and specificity (other) was high; however, the specificity (unknown and other) remained unclear.
Litster, A L; Pogranichniy, R; Lin, T-L
The antemortem diagnosis of feline infectious peritonitis (FIP) remains challenging in clinical practice, since current testing methods have suboptimal diagnostic accuracy. Immunohistochemical testing of biopsy specimens and postmortem examination are the standard diagnostic methods, although direct immunofluorescence (DIF) testing to detect feline coronavirus in macrophages in effusion specimens has been reported to have 100% specificity and has been recommended as an antemortem confirmatory test. The aim of this study was to compare the results of DIF testing in antemortem feline effusions with postmortem results using field samples. Effusion specimens were collected antemortem from 17 cats and tested by DIF, followed by postmortem examination. Histopathological examination of specimens collected at postmortem confirmed FIP in 10/17 cases and ruled out FIP out in 7/17 cases. Antemortem DIF testing was positive in all 10 cases confirmed as FIP at postmortem examination. In the seven cats where FIP was ruled out at postmortem examination, DIF was negative in five cases and positive in the remaining two cases. The calculated sensitivity of DIF testing was 100% and the specificity was 71.4%. Duplicate effusion specimens from eight cats that were initially DIF positive were stored refrigerated (4 °C) or at room temperature (22-25 °C) and subjected to serial DIF testing to determine the duration of positive results. DIF-positive specimens stored at both temperatures retained their positive status for at least 2 days.
Renaud, Nicolas; Lecci, Laetitia; Courcol, René J.; Simonet, Michel
CHROMagar Yersinia (CAY) is a new chromogenic medium for the presumptive detection of virulent Yersinia enterocolitica in stools. Based on a comparative analysis of 1,494 consecutive stools from hospitalized patients, CAY was found to be just as sensitive as the reference medium (cefsulodin-irgasan-novobiocin agar) but was significantly more specific and had a very low false-positive rate. CAY reduces the workload (and thus costs) for stool analysis and can therefore be recommended for routine laboratory use. PMID:23363840
Watts, Matthew R; James, Gregory; Sultana, Yasmin; Ginn, Andrew N; Outhred, Alexander C; Kong, Fanrong; Verweij, Jaco J; Iredell, Jonathan R; Chen, Sharon C-A; Lee, Rogan
An assay to detect Strongyloides stercoralis in stool specimens was developed using the loop-mediated isothermal amplification (LAMP) method. Primers were based on the 28S ribosomal subunit gene. The reaction conditions were optimized and SYTO-82 fluorescent dye was used to allow real-time and visual detection of the product. The product identity was confirmed with restriction enzyme digestion, cloning, and sequence analysis. The assay was specific when tested against DNA from bacteria, fungi and parasites, and 30 normal stool samples. Analytical sensitivity was to < 10 copies of target sequence in a plasmid and up to a 10(-2) dilution of DNA extracted from a Strongyloides ratti larva spiked into stool. Sensitivity was increased when further dilutions were made in water, indicative of reduced reaction inhibition. Twenty-seven of 28 stool samples microscopy and polymerase chain reaction positive for S. stercoralis were positive with the LAMP method. On the basis of these findings, the assay warrants further clinical validation.
Romański, B; Dziedziczko, A; Pawlik-Miskiewicz, K; Wilewska-Klubo, T; Zbikowska-Gotz, M
Cockroach allergy was investigated in a group of 56 patients with atopic bronchial asthma (37 men and 19 women with ages ranging from 16 to 65) all allergic to house dust antigen. In all patients, both intracutaneous tests and bronchial provocation tests were performed with cockroach antigen prepared from the species most common in Poland, Blattella germanica and Blatta orientalis. Positive skin reactions to cockroach antigen were found in 17 patients while an immediate bronchoconstrictive response was noted in 11. In the authors opinion, cockroach antigens may be partly responsible for the antigenic properties of house dust and may play a causative role in some cases of atopic asthma.
Ramanan, Poornima; Espy, M J; Khare, Reeti; Binnicker, M J
A real-time RT-PCR assay was designed to detect and differentiate norovirus genogroups I (GI) and II (GII), with primers and probes targeting the nonstructural polyprotein gene. Stool samples (n = 100) submitted for routine testing by the BioFire FilmArray® GI panel were also tested by the norovirus GI/GII real-time PCR assays. When compared to the FilmArray GI panel, the norovirus real-time PCR assay demonstrated a sensitivity of 77.5% (62/80) and specificity of 95% (19/20). Specimens yielding discordant results (n = 19) were tested at two outside laboratories for adjudication. Following discordant resolution, the adjusted sensitivity and specificity of the norovirus real-time PCR assays were 96.9% (63/65) and 100% (35/35), respectively. These results suggest that the real-time PCR assays are able to accurately detect and differentiate norovirus GI/GII from clinical stool specimens. Furthermore, our report highlights a potential issue with the specificity of the BioFire FilmArray® norovirus assay, which warrants additional investigation.
Marquardt, W W
A qualitative radial immunodiffusion technique is described which detects antigen(s) in feathers from live or dead chickens infected with Marek's disease herpesvirus. Antiserum, which is incorporated into a support medium, reacts with antigen(s) in the feather tip producing a radial precipitin ring. Antigen(s) was detected in 93.3% of experimentally inoculated chickens 21 days postinoculation and in 100% of infected birds subsequently tested through 6 weeks. No antigen was detectable in the feathers of uninoculated control chickens. The technique is simple and rapid to perform. Positive tests could be detected after 1 to 2 hours of incubation. Antigen detection by the radial immunodiffusion test correlated well with other criteria of infection. This technique should have application as a laboratory research tool and as an adjunct for a rapid flock diagnosis of Marek's disease.
Weir, Tiffany L; Manter, Daniel K; Sheflin, Amy M; Barnett, Brittany A; Heuberger, Adam L; Ryan, Elizabeth P
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.
Okazaki, Hiroaki; Mizuno, Motowo; Nasu, Junichirou; Makidono, Chiho; Hiraoka, Sakiko; Yamamoto, Kazuhide; Okada, Hiroyuki; Fujita, Teizo; Tsuji, Takao; Shiratori, Yasushi
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.
Kruglov, Yuri; Yurchenko, Alexander
Objective To estimate HIV incidence and highlight the characteristics of persons at greatest risk of HIV in the Ukraine capital, Kiev. Method Residual samples from newly-diagnosed persons attending the Kiev City AIDS Centre were tested for evidence of recent HIV infection using an avidity assay. Questions on possible risk factors for HIV acquisition and testing history were introduced. All persons (≥16yrs) presenting for an HIV test April’13–March’14 were included. Rates per 100,000 population were calculated using region-specific denominators. Results During the study period 6370 individuals tested for HIV. Of the 467 individuals newly-diagnosed with HIV, 21 had insufficient samples for LAg testing. Of the remaining 446, 39 (8.7%) were classified as recent with an avidity index <1.5ODn, 10 were reclassified as long-standing as their viral load was <1000 copies/mL, resulting in 29 (6.5%) recent HIV infections. The only independent predictor for a recent infection was probable route of exposure, with MSM more likely to present with a recent infection compared with heterosexual contact [Odds Ratio 8.86; 95%CI 2.65–29.60]. We estimated HIV incidence at 21.5 per 100,000 population, corresponding to 466 new infections. Using population estimates for MSM and PWID, incidence was estimated to be between 2289.6 and 6868.7/100,000 MSM, and 350.4 for PWID. Conclusion A high proportion of persons newly-infected remain undiagnosed, with MSM disproportionally affected with one in four newly-HIV-diagnosed and one in three recently-HIV-infected. Our findings should be used for targeted public health interventions and health promotion. PMID:27276170
Costa, Míriam M; Andrade, Hélida M; Bartholomeu, Daniella C; Freitas, Leandro M; Pires, Simone F; Chapeaurouge, Alexander D; Perales, Jonas; Ferreira, André T; Giusta, Mário S; Melo, Maria N; Gazzinelli, Ricardo T
Identification of novel antigens is essential for developing new diagnostic tests and vaccines. We used DIGE to compare protein expression in amastigote and promastigote forms of Leishmania chagasi. Nine hundred amastigote and promastigote spots were visualized. Five amastigote-specific, 25 promastigote-specific, and 10 proteins shared by the two parasite stages were identified. Furthermore, 41 proteins were identified in the Western blot employing 2-DE and sera from infected dogs. From these proteins, 3 and 38 were reactive with IgM and total IgG, respectively. The proteins recognized by total IgG presented different patterns in terms of their recognition by IgG1 and/or IgG2 isotypes. All the proteins selected by Western blot were mapped for B-cell epitopes. One hundred and eighty peptides were submitted to SPOT synthesis and immunoassay. A total of 25 peptides were shown of interest for serodiagnosis to visceral leishmaniasis. In addition, all proteins identified in this study were mapped for T cell epitopes by using the NetCTL software, and candidates for vaccine development were selected. Therefore, a large-scale screening of L. chagasi proteome was performed to identify new B and T cell epitopes with potential use for developing diagnostic tests and vaccines.
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
There is much clinical interest in the development of a low-cost and reliable test for diagnosing inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS), 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 software. Currently, the system is able to distinguish samples from patients with IBS from patients with IBD with a sensitivity and specificity of 76% and 88% respectively, with an overall mean predictive accuracy of 76%.
Otten, S; Iyer, S; Johnson, W; Montgomery, R
Serospecific antigens isolated by EDTA extraction from four serogroups of Legionella pneumophila were analyzed for their chemical composition, molecular heterogeneity by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and immunological properties. The antigens were shown to be lipopolysaccharides and to differ from the lipopolysaccharides of other gram-negative bacteria. The serospecific antigens contained rhamnose, mannose, glucosamine, and two unidentified sugars together with 2-keto-3-deoxyoctonate, phosphate, and fatty acids. The fatty acid composition was predominantly branched-chain acids with smaller amounts of 3-hydroxymyristic acid. The antigens contain periodate-sensitive groups; mannosyl residues were completely cleaved by periodate oxidation. Hydrolysis of the total lipopolysaccharide by acetic acid resulted in the separation of a lipid A-like material that cross-reacted with the antiserum to lipid A from Salmonella minnesota but did not comigrate with it on sodium dodecyl sulfate gels. None of the four antigens contained heptose. All of the antigen preparations showed endotoxicity when tested by the Limulus amebocyte lysate assay. The results of this study indicate that the serogroup-specific antigens of L. pneumophila are lipopolysaccharides containing an unusual lipid A and core structure and different from those of other gram-negative bacteria. Images PMID:3017918
Becker, S L; Marti, H; Zimmermann, S; Vidacek, D; Herrmann, M; Utzinger, J; Schnabel, P A; Bohle, R M
In February 2015, a male patient from Eritrea with persistent abdominal pain and rectal bleeding was diagnosed with Schistosoma mansoni infection upon examination of a rectal biopsy. In May 2015, repeated stool microscopy identified S. mansoni infection in another Eritrean patient with abdominal pain and considerable eosinophilia (34%). Use of point-of-care circulating cathodic antigen (POC-CCA) tests on urine confirmed S. mansoni infection in both patients. Wider application of non-invasive POC-CCA urine tests will improve schistosomiasis diagnosis and clinical management in migrants.
Rúgeles, Laura Cristina; Bai, Jing; Martínez, Aída Juliana; Vanegas, María Consuelo; Gómez-Duarte, Oscar Gilberto
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
Rúgeles, Laura Cristina; Bai, Jing; Martínez, Aída Juliana; Vanegas, María Consuelo; Gómez-Duarte, Oscar Gilberto
The prevalence of diarrheagenic Escherichia 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.
Engjom, Trond; Jurmy, Palwasha; Tjora, Erling; Gilja, Odd Helge; Dimcevski, Georg
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
Ruiz, J; Nunez, M L; Diaz, J; Lorente, I; Perez, J; Gomez, J
A comparative study was carried out to evaluate the performances of different culture media for the recovery of Salmonella spp. from 1,000 routine samples of human stools. By direct plating we tested Salmonella-Shigella agar (SS), Hektoen enteric agar (HE), bismuth sulfite agar (BS), novobiocin-brilliant green-glycerol-lactose agar (NBGL) and SM-ID medium (SM), and after selenite enrichment, we tested all of the media except HE. C8-esterase and oxidase tests were used for the screening of Salmonella spp. on SS and HE. The total number of Salmonella isolates from direct culture was 74, with respective sensitivities and positive predictive values (PPVs) of 78.4 and 61%, 64.9 and 18.7%, 36.5 and 34.2%, 55.4 and 20.7%, and 39.2 and 43.9% for NBGL, SS, HE, BS, and SMID, respectively. After enrichment, the total number of Salmonella isolates was 88. The respective sensitivities and PPVs obtained were 90.9 and 62.5%, 92 and 17%, 90.9 and 32% and 93.2 and 71.3% for NBGL, SS, BS, and SM, respectively. According to our results, NBGL in direct plating was the medium with the highest sensitivity with respect to the sensitivities of the other media, with significant statistical differences (P < 0.05). Likewise, the PPV for NBGL was also the highest (61%). After enrichment in selenite broth, the sensitivities of the four media tested were similar, with the best PPV obtained with SM (71.3%); this was followed by NBGL (62.5%). When C8-esterase was used on SS or HE, the PPVs improved from less than 40% to about 100%. PMID:8904438
Pion, Sébastien D.; Montavon, Céline; Chesnais, Cédric B.; Kamgno, Joseph; Wanji, Samuel; Klion, Amy D.; Nutman, Thomas B.; Boussinesq, Michel
Since the mid-2000s, the immunochromatographic card test (ICT), a point-of-care test for detecting Wuchereria bancrofti circulating filarial antigens (CFAs), has been the backbone for mapping and monitoring lymphatic filariasis (LF) worldwide. Recently, there have been instances in which CFA positivity has been associated with Loa loa microfilaremia. Here, we examined the association, at both the community and individual levels, between L. loa and CFA using additional diagnostic tools (quantitative polymerase chain reaction [qPCR], Og4C3 enzyme-linked immunosorbent assay, and IgG4 antibodies to Wb123 assays) to demonstrate the relationship between L. loa microfilaremia and ICT positivity. In May 2013, peripheral blood was collected during the day from 1,812 individuals living in southern Cameroon. ICT tests were done on the spot, and positive individuals were resampled at night. Results of qPCR and Wb123 assays concurred proving the absence of W. bancrofti infection. Og4C3 assays indicate a quantitative relationship between the level of L. loa microfilaremia and that of CFA. This was confirmed by epidemiological analyses, which reveal a strong association between L. loa microfilaremia and ICT positivity, with 50% of ICT reacting to L. loa when its microfilarial density exceeds 30,000 microfilariae/mL. At the community level, the proportion of positive ICT would exceed 2% when the prevalence of L. loa microfilaremia in the total population is above 20%. This has significant implications in terms of mapping and control of LF caused by W. bancrofti in Loa-endemic areas. Cross-reactivity of ICT with L. loa has to be considered in the context of both individual and community diagnostics. PMID:27729568
Morsy, T A; Alalfy, M S; Sabry, A H; Fikry, A A; El Sharkawy, I M
The histocompatibility antigens have important functions in the development of the immune response, in the development of immunologic tolerance and in the resistance and susceptibility to diseases. In the present study, the frequency of the human leucocytic antigens (HLA) were studied in 31 lousy children with Pediculus h. capitis (head lice) and 14 adults with Phthirus pubis (pubic lice) to evaluate the immune response in their pathogenesis. The patients (children and adults) were parasite-free as indicated by urine, stool and blood analysis and clinical examination. A significant increase was found between HLA-A11 and, -B5 and lousy children with P. h. capitis and between HLA,-A11, -B5 and -B27 and lousy adults with P. pubis. The association between HLA antigens and parasitic infection was discussed.
Drapała, Dorota; Holec-Gąsior, Lucyna; Kur, Józef; Ferra, Bartłomiej; Hiszczyńska-Sawicka, Elżbieta; Lautenbach, Dariusz
The preliminary diagnostic utility of two mixtures of Toxoplasma gondii recombinant antigens (rROP1+rSAG2 and rROP1+rGRA6) in IgG ELISA and IgG avidity test has been evaluated. A total of 173 serum samples from patients with toxoplasmosis and seronegative people were examined. The sensitivity of IgG ELISA for rROP1+rSAG2 and rROP1+rGRA6 was 91.1% and 76.7%, respectively, while the reactivity for sera from patients where acute toxoplasmosis was suspected was higher, at 100% and 95.4%, respectively, than for people with chronic infection, at 88.2% and 70.6%. In this study a different trend in avidity maturation of IgG antibodies for two mixtures of proteins in comparison with native antigen was observed. The results suggest that a new IgG avidity test using the mixtures of recombinant antigens may be useful for the diagnosis of difficult-to-identify phases of toxoplasmosis. For this reason, selected mixtures after the additional tests on groups of sera with well-defined dates of infection could be used as a better alternative to the native antigens of the parasite in the serodiagnosis of human T. gondii infection.
Fernández-Soto, Pedro; Gandasegui Arahuetes, Javier; Sánchez Hernández, Alicia; López Abán, Julio; Vicente Santiago, Belén; Muro, Antonio
Background Human schistosomiasis, mainly due to Schistosoma mansoni species, is one of the most prevalent parasitic diseases worldwide. To overcome the drawbacks of classical parasitological and serological methods in detecting S. mansoni infections, especially in acute stage of the disease, development of cost-effective, simple and rapid molecular methods is still needed for the diagnosis of schistosomiasis. A promising approach is the loop-mediated isothermal amplification (LAMP) technology. Compared to PCR-based assays, LAMP has the advantages of reaction simplicity, rapidity, specificity, cost-effectiveness and higher amplification efficiency. Additionally, as results can be inspected by the naked eye, the technique has great potential for use in low-income countries. Methodology/Principal findings A sequence corresponding to a mitochondrial S. mansoni minisatellite DNA region was selected as a target for designing a LAMP-based method to detect S. mansoni DNA in stool samples. We used a S. mansoni murine model to obtain well defined stool and sera samples from infected mice with S. mansoni cercariae. Samples were taken weekly from week 0 to 8 post-infection and the Kato-Katz and ELISA techniques were used for monitoring the infection. Primer set designed were tested using a commercial reaction mixture for LAMP assay and an in house mixture to compare results. Specificity of LAMP was tested using 16 DNA samples from different parasites, including several Schistosoma species, and no cross-reactions were found. The detection limit of our LAMP assay (SmMIT-LAMP) was 1 fg of S. mansoni DNA. When testing stool samples from infected mice the SmMIT-LAMP detected S. mansoni DNA as soon as 1 week post-infection. Conclusions/Significance We have developed, for the first time, a cost-effective, easy to perform, specific and sensitive LAMP assay for early detection of S. mansoni in stool samples. The method is potentially and readily adaptable for field diagnosis and
Iha, Yoshikazu; Higa, Futoshi; Sunagawa, Satoko; Naka, Masamitsu; Cash, Haley L; Miyagi, Kazuya; Haranaga, Shusaku; Tateyama, Masao; Uno, Tsukasa; Fujita, Jiro
Climatic conditions may have affected the incidence of influenza during the pandemic of 2009 as well as at other times. This study evaluated the effects of climatic conditions on influenza incidence in Okinawa, a subtropical region in Japan, during the 2009 pandemic using surveillance data from rapid antigen test (RAT) results. Weekly RAT results performed in four acute care hospitals in the Naha region of the Okinawa Islands from January 2007 to July 2011 were anonymously collected for surveillance of regional influenza prevalence. Intense epidemic peaks were noted in August 2009 and December 2009-January 2010 during the influenza pandemic of 2009. RAT positivity rates were lower during the pandemic period than during the pre- and post-pandemic periods. Lower ambient temperature was associated with higher influenza incidence during pre- and post-pandemic periods but not during the pandemic of 2009. Lower relative humidity was associated with higher influenza incidence during the pandemic as well as during the other two periods. The association of climatic conditions and influenza incidence was less prominent during the pandemic of 2009 than during pre- and post-pandemic periods.
[The evaluation of different agglutination and adhesion tests with erythrocytic reagents in determining antibodies to the O and H antigens of Salmonella typhimurium in comparison with immunoenzyme analysis (IEA)].
Karal'nik, B V; Denisova, T G
The comparison of the effectiveness of EIA with that of a number of agglutination and adhesion tests with erythrocyte diagnostica in the determination of antibodies to different S.typhimurium antigens demonstrated higher sensitivity of EIA. The relative specificity of the determination of O- and H-antibodies in EIA and in agglutination and adhesion tests depended on the isotype of antibodies to be determined and the specificity of sensitins used in the production of immunoreagents.
Graves, Christopher J; Ros, Vera I D; Stevenson, Brian; Sniegowski, Paul D; Brisson, Dustin
The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide an experimentally tractable system to test whether natural selection has favored mechanisms that increase evolvability. Many antigenic variation systems consist of paralogous unexpressed 'cassettes' that recombine into an expression site to rapidly alter the expressed protein. Importantly, the magnitude of antigenic change is a function of the genetic diversity among the unexpressed cassettes. Thus, evidence that selection favors among-cassette diversity is direct evidence that natural selection promotes antigenic evolvability. We used the Lyme disease bacterium, Borrelia burgdorferi, as a model to test the prediction that natural selection favors amino acid diversity among unexpressed vls cassettes and thereby promotes evolvability in a primary surface antigen, VlsE. The hypothesis that diversity among vls cassettes is favored by natural selection was supported in each B. burgdorferi strain analyzed using both classical (dN/dS ratios) and Bayesian population genetic analyses of genetic sequence data. This hypothesis was also supported by the conservation of highly mutable tandem-repeat structures across B. burgdorferi strains despite a near complete absence of sequence conservation. Diversification among vls cassettes due to natural selection and mutable repeat structures promotes long-term antigenic evolvability of VlsE. These findings provide a direct demonstration that molecular mechanisms that enhance evolvability of surface antigens are an evolutionary adaptation. The molecular evolutionary processes identified here can serve as a model for the evolution of antigenic evolvability in many pathogens which utilize similar strategies to establish chronic infections.
Hanon, J-B; Van der Stede, Y; Antonissen, A; Mullender, C; Tignon, M; van den Berg, T; Caij, B
Control of bovine viral diarrhoea (BVD) in Belgium is currently implemented on a voluntary basis at herd level and mainly relies on detection and culling of persistently infected (PI) animals. The present field study was conducted during the winter of 2010/2011 to assess the performances of diagnostic assays used in the testing scheme for BVD as proposed by the two Belgian regional laboratories. Individual blood samples were collected from 4972 animals, and individual samples from the same herd were pooled (maximum of 30 individual samples per pool) and screened for the presence of Bovine Viral Diarrhoea Virus (BVDV)-specific RNA using a commercial real-time RT-PCR test (ADIAGENE). Individual samples from positive pools were then tested in parallel with the same RT-PCR test and with an antigen-capture ELISA test (IDEXX) to detect viremic animals. This study demonstrated that individual results differed according to the type of assay used (P < 0.001): 140 animals (2.8%) were positive by RT-PCR and 72 (1.4%) by antigen-ELISA. A second blood sample was taken 40 days later from 74 PCR positive animals to detect persistent viremia: 17 (23%) of these were still PCR positive and considered to be PI and the 57 that no longer tested positive were assumed to be transiently infected (TI) animals. All PI animals were positive also by antigen-ELISA at both time points. Among TI animals, 10 (16%) were positive by antigen-ELISA at the first but none at the second sampling. A highly significant difference in cycle threshold (Ct ) values obtained by RT-PCR was observed between PI and TI animals. ROC analysis was performed to establish thresholds to confirm with high probability that an animal is PI, based on the result of RT-PCR test performed on a single individual blood sample.
Evans, D G; Satterwhite, T K; Evans, D J; DuPont, H L
Double-blind studies were performed to compare the virulence of enterotoxigenic Escherichia coli with and without the fimbriate colonization factor antigen (CFA), using young healthy adults (mean age, 23 years) as volunteers. In the first study one group of volunteers ingested 1 X 10(6) E. coli H-10407, the CFA-positive strain, and another group ingested 1 X 10(6) E. coli H-10407-P, the CFA-negative spontaneous derivative of strain H-10407. The second study was similar except that the test strains were administered at a dose of 1 X 10(8) viable cells. Three parameters of infection were monitored: (i) diarrhea and associated symptoms; (ii) excretion pattern of test strains; and (iii) humoral antibody response to CFA, somatic antigen, and heat-labile enterotoxin. Significant signs of illness occurred only in six of seven volunteers who ingested E. coli H-10407 at a dose of 1 X 10(8). At both doses, E. coli H-10407-P appeared in the stool on day 1 postchallenge and disappeared by day 4. In contrast, strain H-10407 was persistently excreted from the first to the last day of the study. Also, only those volunteers in the H-10407 challenge groups (12 of 13 analyzed) responded with a fourfold antibody titer rise to CFA, somatic antigen, and/or heat-labile enterotoxin. No reversion of H-10407-P to H-10407 was detected. PMID:346488
Yoon, Jihoon G; Kang, Jin Seok; Hwang, Seung Yong; Song, Jaewoo; Jeong, Seok Hoon
Two different methods - the semi-automated magnetic bead-based kit (SK, Stool DNA/RNA Purification kit®) and the manual membrane column-based kit (QS, QIAamp® DNA Stool Mini kit) - for purifying nucleic acids from clinical stool samples were compared and evaluated. The SK kit was more user-friendly than QS due to the reduced manual processing, partial automation, and short turnaround time with half cost. Furthermore, SK produced high yields in both DNA and RNA extractions but poor purity in RNA extraction. In the assessment of rotavirus and Clostridium difficile infection, both kits had equivalent or more sensitive performance compared with the standard method. Although SK showed some interference and inhibition in nucleic acid extraction, the performance, including the repeatability, linearity, analytical sensitivity, and matrix effect, was sufficient for routine clinical use.
Ito, Miyabi; Yamashita, Teruo; Tsuzuki, Hideaki; Kabashima, Yuka; Hasegawa, Akiko; Nagaya, Satoko; Kawaguchi, Mariko; Kobayashi, Shinichi; Fujiura, Akira; Sakae, Kenji; Minagawa, Hiroko
Between April 1999 and March 2008, a total of 4,976 stool specimens collected from patients with suspected viral infection through infectious agent surveillance in Aichi, Japan, were tested for the presence of human parechoviruses (HPeVs). We detected HPeVs in 110 samples by either cell culture, reverse transcriptase PCR (RT-PCR), or both. Serotyping either by neutralization test or by nucleotide sequence determination and phylogenetic analysis of the VP1 region and 5' untranslated region (5'UTR) regions revealed that 63 were HPeV type 1 (HPeV-1), followed by 44 HPeV-3 strains, 2 HPeV-4 strains, and 1 HPeV-6 strain. The high nucleotide and amino acid sequence identities of the Japanese HPeV-3 isolates in 2006 to the strains previously reported from Canada and Netherlands confirmed the worldwide prevalence of HPeV-3 infection. Ninety-seven percent of the HPeV-positive patients were younger than 3 years, and 86.2% younger than 12 months. The clinical diagnoses of HPeV-positive patients were gastroenteritis, respiratory illness, febrile illness, exanthema, "hand, foot, and mouth disease," aseptic meningitis, and herpangina. Among 49 HPeV-positive patients with gastroenteritis, 35 were positive with HPeV-1 and 12 with HPeV-3, and out of 25 with respiratory illness, 11 were positive with HPeV-1 and 14 with HPeV-3. HPeV-3 seemed to be an important etiological agent of respiratory infection of children. While HPeV-1 was detected predominantly during fall and winter, the majority of the HPeV-3 cases were detected during summer and fall. A different pattern of clinical manifestations as well as seasonality suggested that there are different mechanisms of pathogenesis between HPeV-1 and HPeV-3 infections.
Zhou, Yanjiao; Wylie, Kristine M.; El Feghaly, Rana E.; Mihindukulasuriya, Kathie A.; Elward, Alexis; Haslam, David B.; Storch, Gregory A.
The potential to rapidly capture the entire microbial community structure and/or gene content makes metagenomic sequencing an attractive tool for pathogen identification and the detection of resistance/virulence genes in clinical settings. Here, we assessed the consistency between PCR from a diagnostic laboratory, quantitative PCR (qPCR) from a research laboratory, 16S rRNA gene sequencing, and metagenomic shotgun sequencing (MSS) for Clostridium difficile identification in diarrhea stool samples. Twenty-two C. difficile-positive diarrhea samples identified by PCR and qPCR and five C. difficile-negative diarrhea controls were studied. C. difficile was detected in 90.9% of C. difficile-positive samples using 16S rRNA gene sequencing, and C. difficile was detected in 86.3% of C. difficile-positive samples using MSS. CFU inferred from qPCR analysis were positively correlated with the relative abundance of C. difficile from 16S rRNA gene sequencing (r2 = −0.60) and MSS (r2 = −0.55). C. difficile was codetected with Clostridium perfringens, norovirus, sapovirus, parechovirus, and anellovirus in 3.7% to 27.3% of the samples. A high load of Candida spp. was found in a symptomatic control sample in which no causative agents for diarrhea were identified in routine clinical testing. Beta-lactamase and tetracycline resistance genes were the most prevalent (25.9%) antibiotic resistance genes in these samples. In summary, the proof-of-concept study demonstrated that next-generation sequencing (NGS) in pathogen detection is moderately correlated with laboratory testing and is advantageous in detecting pathogens without a priori knowledge. PMID:26637379
Albert, M J; Islam, D; Nahar, S; Qadri, F; Falklind, S; Weintraub, A
In a previous study using pure bacterial cultures in a PCR assay, a primer pair corresponding to a unique chromosomal region of Vibrio cholerae O139 Bengal generated an amplicon from only V. cholerae O139 Bengal. PCR with the same primer pair was used to screen 180 diarrheal stool specimens. All the 67 V. cholerae O139 culture-positive stool specimens were positive by PCR, and the remaining specimens, which contained either other recognized enteric pathogens or no pathogens, were all negative by PCR. PMID:9163504
Franciscovich, Amy; Vaidya, Dhananjay; Doyle, Joe; Bolinger, Josh; Capdevila, Montserrat; Rice, Marcus; Hancock, Leslie; Mahr, Tanya; Mogul, Douglas B
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
Pedersen, Niels; Liu, Hongwei; Millon, Lee; Greer, Kimberly
A significantly increased risk for a number of autoimmune and infectious diseases in purebred and mixed-breed dogs has been associated with certain alleles or allele combinations of the dog leukocyte antigen (DLA) class II complex containing the DRB1, DQA1, and DQB1 genes. The exact level of risk depends on the specific disease, the alleles in question, and whether alleles exist in a homozygous or heterozygous state. The gold standard for identifying high-risk alleles and their zygosity has involved direct sequencing of the exon 2 regions of each of the 3 genes. However, sequencing and identification of specific alleles at each of the 3 loci are relatively expensive and sequencing techniques are not ideal for additional parentage or identity determination. However, it is often possible to get the same information from sequencing only 1 gene given the small number of possible alleles at each locus in purebred dogs, extensive homozygosity, and tendency for disease-causing alleles at each of the 3 loci to be strongly linked to each other into haplotypes. Therefore, genetic testing in purebred dogs with immune diseases can be often simplified by sequencing alleles at 1 rather than 3 loci. Further simplification of genetic tests for canine immune diseases can be achieved by the use of alternative genetic markers in the DLA class II region that are also strongly linked with the disease genotype. These markers consist of either simple tandem repeats or single nucleotide polymorphisms that are also in strong linkage with specific DLA class II genotypes and/or haplotypes. The current study uses necrotizing meningoencephalitis of Pug dogs as a paradigm to assess simple alternative genetic tests for disease risk. It was possible to attain identical necrotizing meningoencephalitis risk assessments to 3-locus DLA class II sequencing by sequencing only the DQB1 gene, using 3 DLA class II-linked simple tandem repeat markers, or with a small single nucleotide polymorphism array
Carneiro, Teiliane Rodrigues; Peralta, Regina Helena Saramago; Pinheiro, Marta Cristhiany Cunha; de Oliveira, Sara Menezes; Peralta, José Mauro; Bezerra, Fernando Schemelzer Moraes
The aim of this study was to evaluate the efficacy of a polymerase chain reaction (PCR)-based method to detect Schistosoma mansoni DNA in stool samples from individuals living in a low-endemicity area in Brazil. Of the 125 initial stool samples, 80 were ELISA reactive and eggs were identified in 19 of the samples by parasitological examination. For the PCR evaluations, 56 stool samples were selected and divided into five groups. Groups I-IV were scored negative for S. mansoni eggs by parasitological examination. Groups I and II were ELISA reactive, whereas Groups III and IV were ELISA nonreactive. Groups II and III were positive for other intestinal parasites. PCR testing scored eight samples as positive from these four groups. Group V represented the S. mansoni -positive group and it included ELISA-reactive samples that were scored positive for S. mansoni by one or more parasitological examinations (6/19 were positive by Kato-Katz method, 9/17 by saline gradient and 10/13 by Helmintex®). PCR scored 13 of these 19 samples as positive for S. mansoni . We conclude that while none of these methods yielded 100% sensitivity, a combination of techniques should be effective for improving the detection of S. mansoni infection in low-endemicity areas. PMID:24402156
Couturier, Brianne A; Jensen, Ryan; Arias, Nora; Heffron, Michael; Gubler, Elyse; Case, Kristin; Gowans, Jason; Couturier, Marc Roger
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
Clabots, Connie; Porter, Stephen B.; Thuras, Paul; Johnson, James R.
Emerging multidrug-resistant (MDR) Gram-negative bacilli (GNB), including Escherichia coli sequence type 131 (ST131) and its resistance-associated H30 subclone, constitute an ever-growing public health threat. Their reservoirs and transmission pathways are incompletely defined. To assess diarrheal stools as a potential reservoir for ST131-H30 and other MDR GNB, we cultured 100 clinical stool samples from a Veterans Affairs Medical Center clinical laboratory (October to December 2011) for fluoroquinolone- and extended-spectrum cephalosporin (ESC)-resistant E. coli and other GNB, plus total E. coli. We then characterized selected resistant and susceptible E. coli isolates by clonal group, phylogenetic group, virulence genotype, and pulsotype and screened all isolates for antimicrobial resistance. Overall, 79 of 100 stool samples yielded GNB (52 E. coli; 48 other GNB). Fifteen samples yielded fluoroquinolone-resistant E. coli (10 were ST131, of which 9 were H30), 6 yielded ESC-resistant E. coli (2 were ST131, both non-H30), and 31 yielded susceptible E. coli (1 was ST131, non-H30), for 13 total ST131-positive samples. Fourteen non-E. coli GNB were ESC resistant, and three were fluoroquinolone resistant. Regardless of species, almost half (46%) of the fluoroquinolone-resistant and/or ESC-resistant non-E. coli GNB were resistant to at least three drug classes. Fecal ST131 isolates closely resembled reference clinical ST131 isolates according to virulence genotypes and pulsed-field gel electrophoresis (PFGE) profiles. Thus, a substantial minority (30%) of veterans with diarrhea who undergo stool testing excrete antibiotic-resistant GNB, including E. coli ST131. Consequently, diarrhea may pose transmission risks for more than just diarrheal pathogens and may help disseminate clinically relevant ST131 strains and other MDR GNB within hospitals and the community. PMID:27185805
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.
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
McRorie, J; Zorich, N; Riccardi, K; Bishop, L; Filloon, T; Wason, S; Giannella, R
The aim of this study was to determine the effects of olestra and sorbitol consumption on three accepted objective measures of diarrhea (stool output >250 g/day, liquid/watery stools, bowel movement frequency >3/day), and how stool composition influences reports of common gastrointestinal symptoms. A double-blind, placebo-controlled study compared the effects of sorbitol (40 g/day in candy), a poorly absorbed sugar-alcohol with known osmotic effects, with those of olestra (20 or 40 g/day in potato chips), a nonabsorbed fat, on objective measures of stool composition and GI symptoms. Sixty-six subjects resided on a metabolic ward for 12 days: 2 days lead-in, 4 days baseline, 6 days treatment. Sorbitol 40 g/day resulted in loose/liquid stools within 1-3 h of consumption. In contrast, olestra resulted in a dose-responsive stool softening effect after 2-4 days of consumption. Subjects reported "diarrhea" when mean stool apparent viscosity (peak force (PF), g) decreased from a perceived "normal" (mean +/- SE, 1355 +/- 224 g PF; firm stool) to loose (260 +/- 68 g PF) stool. Mean apparent viscosity of stool during treatment: placebo, 1363 +/- 280 g (firm); olestra 20 g/day 743 +/- 65 g (soft); olestra 40 g/day, 563 +/- 105 g (soft); and sorbitol 40 g/day, 249 +/- 53 g (loose). Of the 1098 stool samples collected, 38% (419/1098) were rated by subjects as "diarrhea," yet only 2% of treatment days (all in the sorbitol treatment group) met commonly accepted criteria for a clinical diarrhea. Sorbitol, but not olestra, increased the severity of abdominal cramping, urgency and nausea compared to placebo. Olestra consumption, at levels far in excess of normal snacking conditions, resulted in a gradual stool softening effect after several days of consumption, did not meet any of the three objective measures of diarrhea, and did not increase GI symptoms. Sorbitol consumption, at only 80% of the dose requiring a "laxative effect" information label, resulted in rapid onset loose
Palsson, Olafur S.; Baggish, Jeffrey S.; Turner, Marsha J.; Whitehead, William E.
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
Eigner, U; Hiergeist, A; Veldenzer, A; Rohlfs, M; Schwarz, R; Holfelder, M
Diarrheagenic E. coli (DEC) are one of the most common causes for diarrhea worldwide, especially in children. We evaluated the rapid RIDA ® GENE (RG) real-time multiplex PCR assays (R-Biopharm, Darmstadt, Germany) for the detection of the most important diarrheagenic E. coli. Three hundred fifteen liquid or non-formed stool specimens were examined. The results of the RG multiplex assays were compared to specific PCR methods. The sensitivity and specificity of the RG PCRs were as follows, 100%/100% for the detection of EHEC, 96.3% and 99% for EPEC, 100% and 100% for the detection of EAEC, ETEC and EIEC, respectively. Overall, the RG real-time PCR system for the detection of DEC tested in this study provided reliable and rapid results and shows the ability as a useful addendum for the detection of diarrheagenic E. coli in the medical laboratory.
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
Mota-Hernández, F; Bross-Soriano, D; Pérez-Ricardez, M L; Velásquez-Jones, L
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.
Magaña, Laura; Aswath, Kshama; Collins, Nikail; Vinjé, Jan; Oberste, M. Steven
ABSTRACT The complete coding sequences of three melon necrotic spot viruses (MNSVs) were obtained from viral metagenomics of stool samples from patients with acute gastroenteritis. These genomes were most similar to Spanish strains sequenced in 2003 and a novel MNSV watermelon strain in 2014. PMID:28302791
Drawing from a critical qualitative inquiry, this case study tells the story of Hana, a Korean-Canadian mother, and identifies barriers that can be encountered in seeking to interact with school professionals in the special education milieu. The case study presents a conceptual model, called the three-legged stool of parental inclusion, which is…
Na-Ek, Prasit; Sanpool, Oranuch; Jongthawin, Jurairat; Anamnart, Witthaya; Intapan, Pewpan M; Chamavit, Pennapa; Maleewong, Wanchai
Hookworm infection is still prevalent in southern Thailand despite control measures. Hookworm eggs submerged for an extended period under water from rainfall or in latrines may not survive, but they may recover their ability to develop into infective larvae when exposed to atmospheric air. This study examined the survival of the hookworm eggs in stool suspension and the restoration of development capability after prolonged storage. In stool mass, eggs developed normally and yielded infective filariform larvae (FL) in 7 days. On the contrary, in 1:10 stool suspension, hookworm eggs were found to remain at the 4-8 cell stage; degenerated eggs were observed after 15 days of storage, and the number of degenerated eggs reached 80 % on day 30. Aeration of the suspension, or transferring to a Petri dish or agar plate, restored the capacity of eggs stored for up to 15 days to develop into FL; thereafter, the capacity declined sharply. Retardation of egg development under water or in stool suspension may be due to a lack of atmospheric air. Use of "night soil" from latrines as fertilizer may be one factor in maintaining hookworm transmission, as worm eggs can undergo normal development upon exposure to atmospheric air.
Chrzanowski, Rose-Ann C.
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…
Nielsen, Hans Linde; Engberg, Jørgen; Ejlertsen, Tove; Nielsen, Henrik
One thousand seven hundred ninety-one diarrheic stool samples were cultivated for Campylobacter spp. We found a high prevalence of Campylobacter concisus with use of a polycarbonate filter (n = 114) compared to a cellulose acetate filter (n = 79) (P < .0001). The polycarbonate filter is superior to the commonly used cellulose acetate filter for detection of C. concisus.
Buchan, Blake W; Mackey, Tami-Lea A; Daly, Judy A; Alger, Garrison; Denys, Gerald A; Peterson, Lance R; Kehl, Sue C; Ledeboer, Nathan A
We compared the Portrait Toxigenic C. difficile Assay, a new semiautomated sample-to-result molecular test, to a toxigenic bacterial culture/cell cytotoxin neutralization assay (TBC/CCNA) for the detection of toxigenic Clostridium difficile in 549 stool specimens. Stool specimens were also tested by one of three alternative FDA-cleared molecular tests for toxigenic C. difficile (Xpert C. difficile, Illumigene C. difficile, or GeneOhm Cdiff). The sensitivities and specificities of the molecular tests compared to TBC/CCNA were as follows: 98.2% and 92.8% for the Portrait assay, 100% and 91.7% for the Xpert assay, 93.3% and 95.1% for the Illumigene assay, and 97.4% and 98.5% for the GeneOhm assay, respectively. The majority of Portrait false-positive results (20/31; 64.5%) were also positive for C. difficile by an alternative molecular test, suggesting an increased sensitivity compared to the culture-based "gold standard" method. The Portrait test detected an assay input of 30 CFU in 100% of spiked samples and detected an input of 10 CFU in 96.7% of samples tested.
Aksoycan, N; Sağanak, I; Wells, G
The immune sera for Brettanomyces lambicus, B. claussenii, Debaryomyces hansenii and D. marama agglutinated Salmonella cholerae-suis (0:6(2), 7). The immune serum for S. cholerae-suis agglutinated B. lambicus, B. clausenni, D. hansenii and D. marama. Absorption and agglutination cross-tested demonstrated common antigen factor(s) in the tested yeasts and Salmonella 0:7 antigen.
Echeverria, P; Verheart, L; Ulyanco, C V; Santiago, L T
The Y1 adrenal cell tissue culture assay was used to detect heat-labile enterotoxin-like activity in the stools of 14 of 74 patients with diarrhea. A positive effect of the stool on the adrenal cells was heat-labile and neutralized by cholera antitoxin. Enterotoxin-like activity was detected in the stools of 10 of 30 patients with cholera and in those of 2 of 4 from whom heat-labile Escherichia coli were isolated. None of the stools from nine individuals with Vibrio parahaemolyticus, Salmonella, or Shigella infections were positive. Two of 31 individuals from whom no pathogens were isolated had detectable toxin-like activity in their stools. The Y1 adrenal cell assay provides a rapid method of diagnosing heat-labile enterotoxigenic diarrhea and could be an adjunct in epidemiological studies of gastroenteritis. PMID:342414
Ciocchini, Andrés E.; Rey Serantes, Diego A.; Melli, Luciano J.; Iwashkiw, Jeremy A.; Deodato, Bettina; Wallach, Jorge; Feldman, Mario F.; Ugalde, Juan E.; Comerci, Diego J.
Brucellosis is a highly contagious zoonosis and still a major human health problem in endemic areas of the world. Although several diagnostic tools are available, most of them are difficult to implement especially in developing countries where complex health facilities are limited. Taking advantage of the identical structure and composition of the Brucella spp. and Yersinia enterocolitica O:9 O-polysaccharide, we explored the application of a recombinant Y. enterocolitica O:9-polysaccharide-protein conjugate (OAg-AcrA) as a novel antigen for diagnosis of human brucellosis. We have developed and validated an indirect immunoassay using OAg-AcrA coupled to magnetic beads. OAg-AcrA was produced and purified with high yields in Y. enterocolitica O:9 cells co-expressing the oligosaccharyltransferase PglB and the protein acceptor AcrA of Campylobacter jejuni without the need for culturing Brucella. Expression of PglB and AcrA in Y. enterocolitica resulted in the transfer of the host O-polysaccharide from its lipid carrier to AcrA. To validate the assay and determine the cutoff values, a receiver-operating characteristic analysis was performed using a panel of characterized serum samples obtained from healthy individuals and patients of different clinical groups. Our results indicate that, using this assay, it is possible to detect infection caused by the three main human brucellosis agents (B. abortus, B. melitensis and B. suis) and select different cutoff points to adjust sensitivity and specificity levels as needed. A cutoff value of 13.20% gave a sensitivity of 100% and a specificity of 98.57%, and a cutoff value of 16.15% resulted in a test sensitivity and specificity of 93.48% and 100%, respectively. The high diagnostic accuracy, low cost, reduced assay time and simplicity of this new glycoconjugate-magnetic beads assay makes it an attractive diagnostic tool for using not only in clinics and brucellosis reference laboratories but also in locations with limited
Ciocchini, Andrés E; Rey Serantes, Diego A; Melli, Luciano J; Iwashkiw, Jeremy A; Deodato, Bettina; Wallach, Jorge; Feldman, Mario F; Ugalde, Juan E; Comerci, Diego J
Brucellosis is a highly contagious zoonosis and still a major human health problem in endemic areas of the world. Although several diagnostic tools are available, most of them are difficult to implement especially in developing countries where complex health facilities are limited. Taking advantage of the identical structure and composition of the Brucella spp. and Yersinia enterocolitica O:9 O-polysaccharide, we explored the application of a recombinant Y. enterocolitica O:9-polysaccharide-protein conjugate (OAg-AcrA) as a novel antigen for diagnosis of human brucellosis. We have developed and validated an indirect immunoassay using OAg-AcrA coupled to magnetic beads. OAg-AcrA was produced and purified with high yields in Y. enterocolitica O:9 cells co-expressing the oligosaccharyltransferase PglB and the protein acceptor AcrA of Campylobacter jejuni without the need for culturing Brucella. Expression of PglB and AcrA in Y. enterocolitica resulted in the transfer of the host O-polysaccharide from its lipid carrier to AcrA. To validate the assay and determine the cutoff values, a receiver-operating characteristic analysis was performed using a panel of characterized serum samples obtained from healthy individuals and patients of different clinical groups. Our results indicate that, using this assay, it is possible to detect infection caused by the three main human brucellosis agents (B. abortus, B. melitensis and B. suis) and select different cutoff points to adjust sensitivity and specificity levels as needed. A cutoff value of 13.20% gave a sensitivity of 100% and a specificity of 98.57%, and a cutoff value of 16.15% resulted in a test sensitivity and specificity of 93.48% and 100%, respectively. The high diagnostic accuracy, low cost, reduced assay time and simplicity of this new glycoconjugate-magnetic beads assay makes it an attractive diagnostic tool for using not only in clinics and brucellosis reference laboratories but also in locations with limited
Krauth, Stefanie J.; Coulibaly, Jean T.; Knopp, Stefanie; Traoré, Mahamadou; N'Goran, Eliézer K.; Utzinger, Jürg
Background An accurate diagnosis of helminth infection is important to improve patient management. However, there is considerable intra- and inter-specimen variation of helminth egg counts in human feces. Homogenization of stool samples has been suggested to improve diagnostic accuracy, but there are no detailed investigations. Rapid disintegration of hookworm eggs constitutes another problem in epidemiological surveys. We studied the spatial distribution of Schistosoma mansoni and hookworm eggs in stool samples, the effect of homogenization, and determined egg counts over time in stool samples stored under different conditions. Methodology Whole-stool samples were collected from 222 individuals in a rural part of south Côte d'Ivoire. Samples were cut into four pieces and helminth egg locations from the front to the back and from the center to the surface were analyzed. Some samples were homogenized and fecal egg counts (FECs) compared before and after homogenization. The effect of stool storing methods on FECs was investigated over time, comparing stool storage on ice, covering stool samples with a water-soaked tissue, or keeping stool samples in the shade. Principal Findings We found no clear spatial pattern of S. mansoni and hookworm eggs in fecal samples. Homogenization decreased S. mansoni FECs (p = 0.026), while no effect was observed for hookworm and other soil-transmitted helminths. Hookworm FECs decreased over time. Storing stool samples on ice or covered with a moist tissue slowed down hookworm egg decay (p<0.005). Conclusions/Significance Our findings have important implications for helminth diagnosis at the individual patient level and for epidemiological surveys, anthelmintic drug efficacy studies and monitoring of control programs. Specifically, homogenization of fecal samples is recommended for an accurate detection of S. mansoni eggs, while keeping collected stool samples cool and moist delayed the disintegration of hookworm eggs. PMID:23285307
Berger, Barry M; Levin, Bernard; Hilsden, Robert J
Multitarget stool DNA (mt-sDNA) testing was approved for average risk colorectal cancer (CRC) screening by the United States Food and Drug Administration and thereafter reimbursed for use by the Medicare program (2014). The United States Preventive Services Task Force (USPSTF) October 2015 draft recommendation for CRC screening included mt-sDNA as an “alternative” screening test that “may be useful in select clinical circumstances”, despite its very high sensitivity for early stage CRC. The evidence supporting mt-sDNA for routine screening use is robust. The clinical efficacy of mt-sDNA as measured by sensitivity, specificity, life-years gained (LYG), and CRC deaths averted is similar to or exceeds that of the other more specifically recommended screening options included in the draft document, especially those requiring annual testing adherence. In a population with primarily irregular screening participation, tests with the highest point sensitivity and reasonable specificity are more likely to favorably impact CRC related morbidity and mortality than those depending on annual adherence. This paper reviews the evidence supporting mt-sDNA for routine screening and demonstrates, using USPSTF’s modeling data, that mt-sDNA at three-year intervals provides significant clinical net benefits and fewer complications per LYG than annual fecal immunochemical testing, high sensitivity guaiac based fecal occult blood testing and 10-year colonoscopy screening. PMID:27190584
Coulibaly, Jean T; Ouattara, Mamadou; Becker, Sören L; Lo, Nathan C; Keiser, Jennifer; N'Goran, Eliézer K; Ianniello, Davide; Rinaldi, Laura; Cringoli, Giuseppe; Utzinger, Jürg
Accurate diagnostic tools for human helminthiasis are crucial for epidemiological surveys, improved patient management, and evaluation of community-based intervention studies. However, the diagnosis of intestinal schistosomiasis and soil-transmitted helminthiasis heavily relies on stool microscopy using the Kato-Katz technique, which has a low sensitivity. The Mini-FLOTAC method is an alternative microscopy-based technique, but its diagnostic performance using sodium acetate-acetic acid-formalin-(SAF)-fixed stool specimens has not been validated. The fixation of stool samples for later examination in a laboratory may reduce logistical and financial barriers of prevalence surveys by not requiring field laboratories. We compared the diagnostic accuracy of the Kato-Katz technique using fresh stool samples with the Mini-FLOTAC technique, employing matched stool samples that were fixed in SAF. Three consecutive stool samples from 149 school-aged children in Côte d'Ivoire were subjected to quintuplicate Kato-Katz thick smears examined on the same day. From the remaining stool, approximately 2g was fixed in 10ml of SAF for about 3 months, and then subjected to the Mini-FLOTAC method, using two flotation solutions (FS2 and FS7). The combined results of multiple Kato-Katz and Mini-FLOTAC readings revealed prevalences of Schistosoma mansoni, Trichuris trichiura and hookworm of 99.3%, 72.5% and 7.4%, respectively. Employing a Bayesian latent class analysis to estimate the true sensitivity of the diagnostic approaches, the sensitivity of Mini-FLOTAC using FS2 was 50.1% (95% Bayesian credible interval (BCI): 30.9-70.2%) for hookworm and 68.0% (95% BCI: 34.9-93.5%) for T. trichiura. When applying Mini-FLOTAC using FS7, the sensitivity was 89.9% (95% BCI: 86.9-97.4%) for S. mansoni, 37.2% (95% BCI: 17.2-60.6%) for hookworm and 67.7% (95% BCI: 33.0-93.0%) for T. trichiura. The specificity ranged from 80.1-95.0% in all Mini-FLOTAC tests. Mini-FLOTAC revealed higher arithmetic mean
Sahoo, Krushna Chandra; Tamhankar, Ashok J; Sahoo, Soumyakanta; Sahu, Priyadarshi Soumyaranjan; Klintz, Senia Rosales; Lundborg, Cecilia Stålsby
Little information is available on relationships between the biophysical environment and antibiotic resistance. This study was conducted to investigate the antibiotic resistance pattern of Escherichia coli isolated from child stool samples, cow-dung and drinking water from the non-coastal (230 households) and coastal (187 households) regions of Odisha, India. Susceptibility testing of E. coli isolates (n = 696) to the following antibiotics: tetracycline, ampicillin/sulbactam, cefuroxime, cefotaxime, cefixime, cotrimoxazole, amikacin, ciprofloxacin, norfloxacin and nalidixic acid was performed by the disk diffusion method. Ciprofloxacin minimum inhibitory concentration (MIC) values were determined for ciprofloxacin-resistant isolates (n = 83). Resistance to at least one antibiotic was detected in 90% or more of the E. coli isolates. Ciprofloxacin MIC values ranged from 8 to 32 µg/mL. The odds ratio (OR) of resistance in E. coli isolates from children's stool (OR = 3.1, 95% CI 1.18-8.01), cow-dung (OR = 3.6, 95% CI 1.59-8.03, P = 0.002) and drinking water (OR = 3.8, 95% CI 1.00-14.44, P = 0.049) were higher in non-coastal compared to coastal region. Similarly, the co-resistance in cow-dung (OR = 2.5, 95% CI 1.39-4.37, P = 0.002) and drinking water (OR = 3.2, 95% CI 1.36-7.41, P = 0.008) as well as the multi-resistance in cow-dung (OR = 2.2, 95% CI 1.12-4.34, P = 0.022) and drinking water (OR = 2.7, 95% CI 1.06-7.07, P = 0.036) were also higher in the non-coastal compared to the coastal region.
Tang, Y; Saif, Y M
Astroviruses are positive-sense single-stranded RNA viruses. These viruses cause gastroenteritis in humans and in a variety of animal species, including turkey poults. Only human astroviruses are well characterized antigenically. In the current study, two turkey astrovirus isolates, TAstV1987 and TAstV2001, were antigenically compared using cross-neutralization tests in turkey embryos, as well as cross-reactivity of the two isolates by an enzyme-linked immunosorbent assay (ELISA). The antigenic relatedness values (R) were calculated using the Archetti and Horsfall formula. The R value based on the cross-neutralization tests was 0.56%, which indicates that TAstV1987 and TAstV2001 belong to different serotypes; the R value of the two viruses based on ELISA was 70.7%, which suggests these two viruses share common antigen(s).
Secondary cell wall polysaccharides of Bacillus anthracis are antigens that contain specific epitopes which cross-react with three pathogenic Bacillus cereus strains that caused severe disease, and other epitopes common to all the Bacillus cereus strains tested.
Leoff, Christine; Saile, Elke; Rauvolfova, Jana; Quinn, Conrad P; Hoffmaster, Alex R; Zhong, Wei; Mehta, Alok S; Boons, Geert-Jan; Carlson, Russell W; Kannenberg, Elmar L
The immunoreactivities of hydrogen fluoride (HF)-released cell wall polysaccharides (HF-PSs) from selected Bacillus anthracis and Bacillus cereus strains were compared using antisera against live and killed B. anthracis spores. These antisera bound to the HF-PSs from B. anthracis and from three clinical B. cereus isolates (G9241, 03BB87, and 03BB102) obtained from cases of severe or fatal human pneumonia but did not bind to the HF-PSs from the closely related B. cereus ATCC 10987 or from B. cereus type strain ATCC 14579. Antiserum against a keyhole limpet hemocyanin conjugate of the B. anthracis HF-PS (HF-PS-KLH) also bound to HF-PSs and cell walls from B. anthracis and the three clinical B. cereus isolates, and B. anthracis spores. These results indicate that the B. anthracis HF-PS is an antigen in both B. anthracis cell walls and spores, and that it shares cross-reactive, and possibly pathogenicity-related, epitopes with three clinical B. cereus isolates that caused severe disease. The anti-HF-PS-KLH antiserum cross-reacted with the bovine serum albumin (BSA)-conjugates of all B. anthracis and all B. cereus HF-PSs tested, including those from nonclinical B. cereus ATCC 10987 and ATCC 14579 strains. Finally, the serum of vaccinated (anthrax vaccine adsorbed (AVA)) Rhesus macaques that survived inhalation anthrax contained IgG antibodies that bound the B. anthracis HF-PS-KLH conjugate. These data indicate that HF-PSs from the cell walls of the bacilli tested here are (i) antigens that contain (ii) a potentially virulence-associated carbohydrate antigen motif, and (iii) another antigenic determinant that is common to B. cereus strains.
Ragavan, Nanthiney Devi; Kumar, Suresh; Chye, Tan Tian; Mahadeva, Sanjiv; Shiaw-Hooi, Ho
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.
Taylor, Caroline M; Northstone, Kate; Wernimont, Susan M; Emmett, Pauline M
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.
Ragavan, Nanthiney Devi; Kumar, Suresh; Chye, Tan Tian; Mahadeva, Sanjiv; Shiaw-Hooi, Ho
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. PMID:26375823
Dahl, Wendy J; Wright, Arnelle R; Specht, Gretchen J; Christman, Mary; Mathews, Anne; Meyer, Diederick; Boileau, Thomas; Willis, Holly J; Langkamp-Henken, Bobbi
The impact of oligofructose (OF) intake on stool frequency has not been clearly substantiated, while significant gastrointestinal (GI) symptoms have been reported in some individuals. The aim of the present study was to determine the effects of OF on stool frequency and GI symptoms in healthy adults. In an 8-week, randomised, double-blind, parallel-arm study, ninety-eight participants were provided with 16 g OF in yogurt and snack bars (twenty male and thirty female) or matching control foods (seventeen male and thirty-one female), to incorporate, by replacement, into their usual diets. Participants completed a daily online questionnaire recording stool frequency and rating four symptoms: bloating, flatulence, abdominal cramping and noise, each on a Likert scale from '0' for none (no symptoms) to '6' for very severe, with a maximum symptom intensity score of 24 (sum of severities from all four symptoms). Online 24 h dietary recalls were completed during pre-baseline and weeks 4, 6 and 8 to determine fibre intake. When provided with OF foods, fibre intake increased to 24·3 (sem 0·5) g/d from pre-baseline (12·1 (sem 0·5) g/d; P < 0·001). Stool frequency increased with OF from 1·3 (sem 0·2) to 1·8 (sem 0·2) stools per d in males and 1·0 (sem 0·1) to 1·4 (sem 0·1) stools per d in females during intervention weeks compared with pre-baseline (P < 0·05),but did not change for control participants (males: 1·6 (sem 0·2) to 1·8 (sem 0·2); females: 1·3 (sem 0·1) to 1·4 (sem 0·1)). Flatulence was the most commonly reported symptom. Mean GI symptom intensity score was higher for the OF group (3·2 (sem 0·3)) v. control (1·7 (sem 0·1)) (P < 0·01), with few participants reporting above moderate symptoms. No change in symptom intensity occurred over time. Consuming yogurt and snack bars with 16 g OF improves regularity in young healthy adults. However, GI symptoms, resulting from an increase in oligofructose intake, may not diminish with time.
Keller, M A; Turner, J L; Stratton, J A; Miller, M E
Comparison milk and blood lymphocyte blastogenic responses to the K1 antigen of Escherichia coli and lipopolysaccharide (LPS) from E. coli O127,B8 were examined in 16 postpartum women by [3H]thymidine uptake. Rabbit hemolysincoated sheep erythrocyte monolayers were used to deplete macrophages from milk lymphocyte preparations and to enrich for T lymphocytes in order to make milk preparations more comparable to blood preparations. Response was defined as a stimulation index of greater than or equal to 2.0. There was no evidence of selective response to K1 antigen by milk lymphocytes, since both blood and milk lymphocytes responded in four women and neither blood nor milk lymphocytes responded in nine. Milk lymphocytes alone responded to K1 in one woman, whereas blood lymphocytes alone responded in two women. Additional nonpaired milk or blood cultures were available from three women. None of these responded to K1 antigen. Corresponding lymphocyte cultures were stimulated with LPS. A positive K1 response was always accompanied by an LPS response, and the LPS response correlated with the K1 response in 17 of 19 women. Stool cultures examined with an antiserum agar showed no correlation between the presence of K1 E. coli in the stool and milk or blood lymphocyte response to K1 antigen. In the system used here, no selectivity of response of breast milk lymphocytes to K1 antigen was noted. PMID:6991433
Foo, Karen T; Blackstock, Anna J; Ochola, Elizabeth A; Matete, Daniel O; Mwinzi, Pauline N M; Montgomery, Susan P; Karanja, Diana M S; Secor, W Evan
We evaluated the performance of a point-of-contact circulating cathodic antigen assay (POC-CCA) to detect schistosome infections in primary school children (N = 1,801) living in areas with low, moderate, and high Schistosoma mansoni prevalence in western Kenya. The commercially available assay (CCA-1) and a second, experimental formulation (CCA-2) were compared against Kato-Katz stool examinations and an anti-schistosome enzyme-linked immunosorbent assay (ELISA). A latent class model based on the four tests was used to establish "true infection status" in three different zones based on their distance from Lake Victoria. As a screening tool for community treatment according to World Health Organization (WHO) guidelines, the Kato-Katz examination was in closest agreement with the latent class model, followed by the experimental CCA-2, soluble adult worm antigen preparation (SWAP) ELISA, and CCA-1, which had high sensitivity compared with the other tests but was consistently the least specific. Our experience suggests that POC-CCA tests offer a field-friendly alternative to Kato-Katz, but need further interpretation for appropriate field use.
Foo, Karen T.; Blackstock, Anna J.; Ochola, Elizabeth A.; Matete, Daniel O.; Mwinzi, Pauline N. M.; Montgomery, Susan P.; Karanja, Diana M. S.; Secor, W. Evan
We evaluated the performance of a point-of-contact circulating cathodic antigen assay (POC-CCA) to detect schistosome infections in primary school children (N = 1,801) living in areas with low, moderate, and high Schistosoma mansoni prevalence in western Kenya. The commercially available assay (CCA-1) and a second, experimental formulation (CCA-2) were compared against Kato-Katz stool examinations and an anti-schistosome enzyme-linked immunosorbent assay (ELISA). A latent class model based on the four tests was used to establish “true infection status” in three different zones based on their distance from Lake Victoria. As a screening tool for community treatment according to World Health Organization (WHO) guidelines, the Kato-Katz examination was in closest agreement with the latent class model, followed by the experimental CCA-2, soluble adult worm antigen preparation (SWAP) ELISA, and CCA-1, which had high sensitivity compared with the other tests but was consistently the least specific. Our experience suggests that POC-CCA tests offer a field-friendly alternative to Kato-Katz, but need further interpretation for appropriate field use. PMID:25870418
Ferguson, J.; Walker, K.; Thomson, A.B.
Analysis of a modified /sup 14/C-glycocholate breath test on 165 consecutive in-patients being investigated for chronic diarrhea showed that the measurement of /sup 14/CO/sub 2/ between 3 and 6 h after oral dosing of 5 microCi of /sup 14/C-glycocholic acid was of only limited use to distinguish between patients with Crohn's disease (CD), idiopathic bile salt wastage (IBW), or ileal resection (IR) from those with the irritable bowel syndrome (IBS). Continuing /sup 14/CO/sub 2/ collections for up to 24 h was of little more help in establishing the presence of bacterial overgrowth syndrome (BOS) and in distinguishing between BOS and CD. Stool bile acid measurements were of use in differentiating between IBW and IBS, but did not distinguish between CD and BOS or between CD and IR. Since the range of normal values was defined by measurements in the IBS group, a positive test was specific for an organic cause of chronic diarrhea. Even so, the sensitivity of the test was relatively low: CD, 53%; IR, 23%; IBW, /sup 14/%; and BOS, 10%. We believe that the 24-h /sup 14/C-glycocholic breath test combined with the measurement of stool bile acids represents a screening test of only limited use for the identification of organic causes of chronic diarrhea.
Stamper, Paul D.; Cai, Mian; Lema, Clara; Eskey, Kim; Carroll, Karen C.
Active screening for vancomycin-resistant enterococci (VRE) in rectal and stool specimens has been recommended to limit the spread of antimicrobial resistance within certain high-risk populations. Directly from 502 rectal swabs and stool specimens, we evaluated the diagnostic performance of the BD GeneOhm VanR assay (BD GeneOhm, San Diego, CA), a rapid real-time PCR test that detects the presence of vanA and/or vanB genes. The VanR assay was compared to culture consisting of both bile-esculin-azide agar with 6 μg/ml vancomycin (BEAV agar) (BD Diagnostics, Sparks, MD) and BEAV broth with 8 μg/ml vancomycin (Hardy Diagnostics, Santa Maria, CA). Enterococci were identified to the species level using standard biochemical tests and a Phoenix automated microbiology system (BD Diagnostics, Sparks, MD). The susceptibility of the enterococci to vancomycin and teicoplanin was determined using an Etest (AB Biodisk, Solna, Sweden). VRE were initially isolated from 147 cultures, and the VanR assay detected 142 of the 147 positive cultures for a sensitivity of 96.6%. The specificity was 87.0% (309/355) largely due to false positives seen with the vanB portion of the assay. The sensitivity when testing rectal swabs was 98.3%, and the sensitivity for stool samples was 95.4% (P = 0.643). The specificity of rectal swabs was comparable to that of the stool specimens (87.5% and 86.5%, respectively). When used only to detect VanA resistance, the VanR assay was 94.4% (136/144) sensitive and 96.4% (345/358) specific, with positive and negative predictive values of 91.3% and 97.7%, respectively. In summary, the BD GeneOhm VanR assay is a good screening test for VRE in our population of predominantly vanA-colonized patients. However, patient samples testing only vanB positive should be confirmed by another method for the presence of VRE. PMID:17704282
Stamper, Paul D; Cai, Mian; Lema, Clara; Eskey, Kim; Carroll, Karen C
Active screening for vancomycin-resistant enterococci (VRE) in rectal and stool specimens has been recommended to limit the spread of antimicrobial resistance within certain high-risk populations. Directly from 502 rectal swabs and stool specimens, we evaluated the diagnostic performance of the BD GeneOhm VanR assay (BD GeneOhm, San Diego, CA), a rapid real-time PCR test that detects the presence of vanA and/or vanB genes. The VanR assay was compared to culture consisting of both bile-esculin-azide agar with 6 mug/ml vancomycin (BEAV agar) (BD Diagnostics, Sparks, MD) and BEAV broth with 8 mug/ml vancomycin (Hardy Diagnostics, Santa Maria, CA). Enterococci were identified to the species level using standard biochemical tests and a Phoenix automated microbiology system (BD Diagnostics, Sparks, MD). The susceptibility of the enterococci to vancomycin and teicoplanin was determined using an Etest (AB Biodisk, Solna, Sweden). VRE were initially isolated from 147 cultures, and the VanR assay detected 142 of the 147 positive cultures for a sensitivity of 96.6%. The specificity was 87.0% (309/355) largely due to false positives seen with the vanB portion of the assay. The sensitivity when testing rectal swabs was 98.3%, and the sensitivity for stool samples was 95.4% (P = 0.643). The specificity of rectal swabs was comparable to that of the stool specimens (87.5% and 86.5%, respectively). When used only to detect VanA resistance, the VanR assay was 94.4% (136/144) sensitive and 96.4% (345/358) specific, with positive and negative predictive values of 91.3% and 97.7%, respectively. In summary, the BD GeneOhm VanR assay is a good screening test for VRE in our population of predominantly vanA-colonized patients. However, patient samples testing only vanB positive should be confirmed by another method for the presence of VRE.
... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Hepatitis B Surface Antigen. 660.40 Section 660.40...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.40 Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this...
... 21 Food and Drugs 7 2013-04-01 2013-04-01 false Hepatitis B Surface Antigen. 660.40 Section 660.40...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.40 Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this...
... 21 Food and Drugs 7 2012-04-01 2012-04-01 false Hepatitis B Surface Antigen. 660.40 Section 660.40...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.40 Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this...
... 21 Food and Drugs 7 2014-04-01 2014-04-01 false Hepatitis B Surface Antigen. 660.40 Section 660.40...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.40 Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this...
... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Hepatitis B Surface Antigen. 660.40 Section 660.40...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.40 Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this...
Nelson, Eric J; Chowdhury, Ashrafuzzaman; Harris, Jason B; Begum, Yasmin A; Chowdhury, Fahima; Khan, Ashraful I; Larocque, Regina C; Bishop, Anne L; Ryan, Edward T; Camilli, Andrew; Qadri, Firdausi; Calderwood, Stephen B
At the International Centre for Diarrhoeal Disease Research, Bangladesh, one-half of the rice-water stool samples that were culture-positive for Vibrio cholerae did not contain motile V. cholerae by standard darkfield microscopy and were defined as darkfield-negative (DF(-)). We evaluated the host and microbial factors associated with DF status, as well as the impact of DF status on transmission. Viable counts of V. cholerae in DF(-) stools were three logs lower than in DF(+) stools, although DF(-) and DF(+) stools had similar direct counts of V. cholerae by microscopy. In DF(-) samples, non-V. cholerae bacteria outnumbered V. cholerae 10:1. Lytic V. cholerae bacteriophage were present in 90% of DF(-) samples compared with 35% of DF(+) samples, suggesting that bacteriophage may limit culture-positive patients from producing DF(+) stools. V. cholerae in DF(-) and DF(+) samples were found both planktonically and in distinct nonplanktonic populations; the distribution of organisms between these compartments did not differ appreciably between DF(-) and DF(+) stools. This biology may impact transmission because epidemiological data suggested that household contacts of a DF(+) index case were at greater risk of infection with V. cholerae. We propose a model in which V. cholerae multiply in the small intestine to produce a fluid niche that is dominated by V. cholerae. If lytic phage are present, viable counts of V. cholerae drop, stools become DF(-), other microorganisms bloom, and cholera transmission is reduced.
Mank, T G; Zaat, J O; Blotkamp, J; Polderman, A M
The use of sodium acetate acetic acid formalin (SAF)-preserved stool specimens was compared with that of nonpreserved specimens for the recovery of intestinal protozoa. A total of 247 patients, 170 with diarrhea of more than one week's duration and 77 refugees, were asked to collect a stool specimen. Each specimen was placed into two vials, one empty, the other containing SAF fixative. Laboratory investigations included microscopic examination of the concentrated sediment and direct wet smears from both types of stool specimens and the microscopic examination of a permanent stained smear from the unsedimented, SAF-preserved stool specimens. Examination of SAF-preserved stool specimens revealed intestinal protozoa in 149 of the 247 patients. With the conventional procedure using unpreserved stool specimens, intestinal protozoa were found in 89 of the 247 patients. The results show that the examination of SAF-preserved stool specimens, consisting of the microscopic examination of both the concentrated sediment and the permanent stained smear from the unsedimented material, increases the chance of recovering intestinal protozoa as compared to the conventional procedure.
Yera, Hélène; Kuchta, Roman; Brabec, Jan; Peyron, François; Dupouy-Camet, Jean
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.
Krolewiecki, Alejandro J; Ramanathan, Roshan; Fink, Valeria; McAuliffe, Isabel; Cajal, Silvana P; Won, Kimberly; Juarez, Marisa; Di Paolo, Adriana; Tapia, Laura; Acosta, Norma; Lee, Rogan; Lammie, Patrick; Abraham, David; Nutman, Thomas B
The serodiagnosis of Strongyloides stercoralis infection by enzyme-linked immunosorbent assays based on crude antigen (CrAg-ELISA), while useful, has been limited by the reliance on crude parasite extracts. Newer techniques such as the luciferase immunoprecipitation system assay (LIPS), based on a 31-kDa recombinant antigen (termed NIE) from S. stercoralis and/or the recombinant antigen S. stercoralis immunoreactive antigen (SsIR), or the NIE-ELISA have shown promise in controlled settings. We compared each of these serologic assays in individuals from both regions of the world in which S. stercoralis is endemic and those in which it is not. A comprehensive stool evaluation (sedimentation concentration, Baermann concentration with charcoal cultures, agar plate, and Harada-Mori) and four different serologic techniques using CrAg-ELISA or recombinant NIE-ELISA as well as LIPS using NIE alone or in combination with a second recombinant antigen (NIE/SsIR-LIPS) were compared among individuals with parasitologically proven infection (n = 251) and healthy controls from regions of the world in which the infection is nonendemic (n = 11). Accuracy was calculated for each assay. The prevalence of S. stercoralis infection was 29.4% among Argentinean stool samples (n = 228). Sedimentation concentration and Baermann were the most sensitive stool-based methods. NIE-LIPS showed the highest sensitivity (97.8%) and specificity (100%) of the serologic assays. The calculated negative predictive value was highest for both the NIE-LIPS and CrAg-ELISA (>97%) irrespective of disease prevalence. No cross-reactivity with soil-transmitted helminths was noted. NIE-LIPS compares favorably against the current CrAg-ELISA and stool evaluation, providing additional accuracy and ease of performance in the serodiagnosis of S. stercoralis infections irrespective of disease prevalence.
Coll, P; Phillips, K; Tenover, F C
The ability of the Extractor system (Molecular Biosystems, Inc., San Diego, Calif.) to isolate nucleic acid (NA) from stool samples for use in hybridization assays was investigated. Crude NA was recovered from 45 of 50 stool samples by using this system. The amount of NA recovered varied considerably depending on the microbial flora present in the sample (mean +/- standard deviation, 50.2 +/- 46.7 micrograms; range, 2 to 228 micrograms) but did not correlate with the consistency of the sample. Samples containing primarily gram-positive organisms or yeast cells gave lower yields of NA (less than 10 micrograms) than those containing gram-negative bacilli. The five samples which did not yield NA were sterile when cultured aerobically on blood agar plates. Samples of the 45 stools yielding NA were inoculated into broth and grown overnight, and a 10-microliters sample of broth was spotted onto nitrocellulose filters. The NA samples recovered from the Extractor column were applied to nylon membranes by using the Centri-dot system. The NA on the broth blots and the NA on the Centri-dot filters were hybridized with a 310-base-pair probe specific for the 2"-O-aminoglycoside adenylyltransferase [ANT(2")] resistance gene. The Extractor-Centri-dot system demonstrated 61.9% sensitivity and 95.8% specificity in detecting the ANT(2") gene in stool samples containing colonies demonstrating the ANT(2") phenotype. The positive and negative predictive values of the NA blot were 92.8 and 74.2%, respectively. PMID:2584376
Srinivas, V; Puliyel, Jacob M
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!
Pektaş, Bayram; Altintaş, Nazmiye; Akpolat, Nezahat; Gottstein, Bruno
Alveolar echinococcosis (AE), caused by larva stage of Echinococcus multilocularis, is one of the lethal parasitic diseases of man and a major public health problem in many countries in the northern hemisphere. When the living conditions and habits in Turkey were considered in terms of relation with the life cycle of the parasite, it was suggested that AE has been much more common than reported mainly from the Eastern Anatolia region of Turkey. Since in vitro serologic diagnosis tests with high specificity for AE have not been used in our country, most of the cases with liver lesions were misdiagnosed by radiological investigations as malignancies. The aim of this study was to evaluate the diagnostic value of the in-house ELISA methods developed by using three different antigens (EgHF, Em2, EmII/3-10) in the serological diagnosis of AE. The study samples included a total of 100 sera provided by Bern University Parasitology Institute where samples were obtained from patients with helminthiasis and all were confirmed by clinical, parasitological and/or histopathological means. Ten samples from each of the cases infected by E.multilocularis, E.granulosus, Taenia solium, Wuchereria bancrofti, Strongyloides stercolaris, Ascaris lumbricoides, Toxocara canis, Trichinella spiralis, Fasciola hepatica and Schistosoma haematobium were studied. In the study, EgHF (E.granulosus hydatid fluid) antigens were prepared in our laboratory from the liver cyst fluids of sheeps with cystic echinococcosis, however Em2 (E.multilocularis metacestode-purified laminated layer) and EmII/3-10 (E.multilocularis recombinant protoscolex tegument) antigens were provided by Bern University Parasitology Institute. Flat bottom ELISA plates were covered with EgHF, Em2 and EmII/3-10 antigens in the concentrations of 2.5 µg, 1 µg and 0.18 µg per well, respectively, and all sera were tested by EgHF-ELISA, Em2-ELISA and EmII/3-10-ELISA methods. For each tests, the samples which were reactive above the
Mota-Hernández, F; Posadas-Tello, N M; Rodríguez-Leyva, G
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.
Kazerouni, Abbas; Wein, Lawrence M.
Fecal microbiota transplantation is being assessed as a treatment for chronic microbiota-related diseases such as ulcerative colitis. Results from an initial randomized trial suggest that remission rates depend on unobservable features of the fecal donors and observable features of the patients. We use mathematical modeling to assess the efficacy of pooling stools from different donors during multiple rounds of treatment. In the model, there are two types of patients and two types of donors, where the patient type is observable and the donor type (effective or not effective) is not observable. In the model, clinical outcomes from earlier rounds of treatment are used to estimate the current likelihood that each donor is effective, and then each patient in each round is treated by a pool of donors that are currently deemed to be the most effective. Relative to the no-pooling case, pools of size two or three significantly increase the proportion of patients in remission during the first several rounds of treatment. Although based on data from a single randomized trial, our modeling suggests that pooling of stools – via daily cycling of encapsulated stool from several different donors – may be beneficial in fecal microbiota transplantation for chronic microbiota-related diseases. PMID:28068341
Peters, C. J.; Johnson, K. M.
Ig levels were determined by radial immunodiffusion in uncomplicated cases of acute hepatitis with or without Australia antigenaemia. Initial sera from Australia antigen negative cases showed a striking elevation in IgM levels when compared to Australia antigen positive cases (6·5 versus 1·9 mg/ml). None of twenty-four Australia antigen positive cases exceeded 3 mg/ml IgM, and only 3/58 Australia antigen negative cases exhibited values below 3 mg/ml. Intial sera from Australia antigen positive and Australia antigen negative subjects did not differ in concentration of IgG, IgA, or IgD. Serial determinations of IgG revealed a transient fall in patients with Australia antigen positive hepatitis, and a rise in Australia antigen negative cases. Asymptomatic, Australia antigen positive, Guaymi Indian subjects were compared to matched Australia antigen negative controls from the same indigenous group and no differences in the concentration of IgG, IgM, IgA or IgD were found, although elevations of IgG and IgM were common in both groups. No evidence of abnormal proteins was found when sera were tested by cellulose acetate electrophoresis or by immunoelectrophoresis versus immunoglobulin-specific antisera. Ultracentrifugal analysis failed to detect `7S' IgM. PMID:4625396
... Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for ...
Woodworth, Michael H; Neish, Emma M; Miller, Nancy S; Dhere, Tanvi; Burd, Eileen M; Carpentieri, Cynthia; Sitchenko, Kaitlin L; Kraft, Colleen S
Fecal microbiota transplantation is an efficacious and inexpensive therapy for recurrent Clostridium difficile infection, yet its safety is thought to depend on appropriate fecal donor screening. FDA guidance for regulation of this procedure is in flux, but screening and manufacture of fecal material from asymptomatic donors present many challenges to clinical laboratories. This minireview summarizes FDA regulatory changes, principles of donor selection, and recommended laboratory screening practices for fecal microbiota transplantation.
Cai, Zhipeng; Zhang, Tong; Wan, Xiu-Feng
Influenza viruses have been responsible for large losses of lives around the world and continue to present a great public health challenge. Antigenic characterization based on hemagglutination inhibition (HI) assay is one of the routine procedures for influenza vaccine strain selection. However, HI assay is only a crude experiment reflecting the antigenic correlations among testing antigens (viruses) and reference antisera (antibodies). Moreover, antigenic characterization is usually based on more than one HI dataset. The combination of multiple datasets results in an incomplete HI matrix with many unobserved entries. This paper proposes a new computational framework for constructing an influenza antigenic cartography from this incomplete matrix, which we refer to as Matrix Completion-Multidimensional Scaling (MC-MDS). In this approach, we first reconstruct the HI matrices with viruses and antibodies using low-rank matrix completion, and then generate the two-dimensional antigenic cartography using multidimensional scaling. Moreover, for influenza HI tables with herd immunity effect (such as those from Human influenza viruses), we propose a temporal model to reduce the inherent temporal bias of HI tables caused by herd immunity. By applying our method in HI datasets containing H3N2 influenza A viruses isolated from 1968 to 2003, we identified eleven clusters of antigenic variants, representing all major antigenic drift events in these 36 years. Our results showed that both the completed HI matrix and the antigenic cartography obtained via MC-MDS are useful in identifying influenza antigenic variants and thus can be used to facilitate influenza vaccine strain selection. The webserver is available at http://sysbio.cvm.msstate.edu/AntigenMap.
Igbokwe, H; Bhattacharyya, S; Gradus, S; Khubbar, M; Griswold, D; Navidad, J; Igwilo, C; Masson-Meyers, D; Azenabor, A A
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.
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'.
Tarafder, M R; Carabin, H; Joseph, L; Balolong, E; Olveda, R; McGarvey, S T
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
Becker, Sören L; Piraisoody, Nivetha; Kramme, Stefanie; Marti, Hanspeter; Silué, Kigbafori D; Panning, Marcus; Nickel, Beatrice; Kern, Winfried V; Herrmann, Mathias; Hatz, Christoph F; N'Goran, Eliézer K; Utzinger, Jürg; von Müller, Lutz
Human infections with the helminth species Strongyloides stercoralis encompass a wide clinical spectrum, ranging from asymptomatic carriage to life-threatening disease. The diagnosis of S. stercoralis is cumbersome and the sensitivity of conventional stool microscopy is low. New molecular tools have been developed to increase sensitivity. We compared the diagnostic accuracy of real-time PCR with microscopy for the detection of S. stercoralis and hookworm in human stool samples, and investigated the inter-laboratory agreement of S. stercoralis-specific real-time PCR in two European laboratories. Stool specimens from 256 randomly selected individuals in rural Côte d'Ivoire were examined using three microscopic techniques (i.e. Kato-Katz, Koga agar plate (KAP) and Baermann (BM)). Additionally, ethanol-fixed stool aliquots were subjected to molecular diagnosis. The prevalence of S. stercoralis and hookworm infection was 21.9% and 52.0%, respectively, whilst co-infections were detected in 35 (13.7%) participants. The diagnostic agreement between real-time PCR and microscopy was excellent when both KAP and BM tested positive for S. stercoralis, but was considerably lower when only one microscopic technique was positive. The sensitivity of KAP, BM and real-time PCR for detection of S. stercoralis as compared to a combination of all diagnostic techniques was 21.4%, 37.5% and 76.8%, respectively. The inter-laboratory agreement of S. stercoralis-specific PCR was substantial (κ=0.63, p<0.001). We conclude that a combination of real-time PCR and stool microscopy shows high accuracy for S. stercoralis diagnosis. Besides high sensitivity, PCR may also enhance specificity by reducing microscopic misdiagnosis of morphologically similar helminth larvae (i.e. hookworm and S. stercoralis) in settings where both helminth species co-exist.
Northington, Robert; Kullen, Martin J.; Yao, Manjiang; Bettler, Jodi
Aims. To evaluate the impact of oligofructose (OF)-supplemented infant formula on fecal microbiota, stool characteristics, and hydration. Methods. Ninety-five formula-fed infants were randomized to α-lactalbumin-enriched control formula (CF) or identical formula with 3.0 g/L OF (EF) for 8 weeks; 50 infants fed human milk (HM) were included. Results. Eighty-four infants completed the study, 70 met per-protocol criteria. Over 8 weeks, bifidobacteria increased more in EF than CF group (0.70 vs 0.16 log10 bacterial counts/g dry feces, P = .008); EF was not significantly different from HM group (P = .32). EF group stool consistency was intermediate between CF and HM groups; at week 8, EF group had softer stools than CF (5-point scale: 1 = hard, 5 = watery; consistency score 3.46 vs 2.82, P = .015) without significant differences in stool frequency. Physician-assessed hydration status was normal for all infants. Conclusions. Infant formula with 3.0 g/L OF promoted bifidobacteria growth and softer stools without adversely affecting stool frequency or hydration. PMID:25297064
Beaulieu, Jean-François; Herring, Elizabeth; Kanaoka, Shigeru; Tremblay, Éric
Objective An important criterion for colorectal cancer (CRC) screening is the ability to detect lesions at a curable stage. In the present study, we have assessed the integrin α6 subunit transcript (ITGA6) as part of a stool assay for the detection of colorectal lesions. Results In comparison with control samples, ITGA6 levels were found to be significantly increased at all stages (P < 0.01). Receiver operating characteristic analysis revealed areas under the curve of 0.89 for the prediction of CRC with 81% sensitivity and 88% specificity and of 0.90 for the prediction of advanced adenomas (Ad) with 75% sensitivity and 88% specificity. The ITGA6A variant was also found to be increased relative to ITGA6 in stage II and III CRCs. Combining ITGA6 with other selected transcripts and/or immunochemical fecal occult blood test (iFOBT) results further increased sensitivity and specificity for the detection of colorectal lesions. Patients and Methods ITGA6 detection used alone and under various combinations including detection of other mRNA markers and iFOBT was assessed on stool samples obtained from 175 patients (91 CRCs, 24 Ad and 60 healthy controls). Conclusions These data confirm the usefulness and reliability of an mRNA stool assay for the detection of colorectal lesions. The validation of additional candidate genes and their analysis in multiplex qPCR represents a powerful and robust approach that can be combined with iFOBT results to improve the detection of colorectal lesions. PMID:26895101
Janoff, E N; Craft, J C; Pickering, L K; Novotny, T; Blaser, M J; Knisley, C V; Reller, L B
Antigen detection methods may facilitate diagnosis of Giardia lamblia in stool specimens. As determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis and immunoblotting, G. lamblia cysts and trophozoites share several antigens, especially in the 65-kilodalton and 30- to 34-kilodalton regions. By using blind methods, we compared results obtained by counterimmunoelectrophoresis using cyst-immune rabbit serum and by enzyme-linked immunosorbent assay (ELISA) using trophozoite-immune rabbit serum with results obtained by microscopic examination of a preserved, concentrated, and permanently stained stool specimen. Results were similar when these three methods were used to examine 118 stool specimens from clinical microbiology laboratories (53 specimens with G. lamblia) and specimens from 239 day-care-center toddlers (39 specimens with G. lamblia). Compared with microscopy, we found, for counterimmunoelectrophoresis and ELISA, respectively: sensitivity, 88 versus 94%; specificity, 97 versus 95%; positive predictive value, 86 versus 76%; negative predictive value, 98 versus 97%; and concordance, 89%. The false-positive rate by ELISA was 24% (10 of 42) in day-care-center toddlers but only 3% (1 of 32) in healthy adults (P less than 0.04) as corroborated by microscopy. This discrepancy suggests that the ELISA may be more sensitive than microscopy, which is considered the reference standard, and that results may be dependent, in part, on the epidemiology of the infection in the study subjects.
Janoff, E N; Craft, J C; Pickering, L K; Novotny, T; Blaser, M J; Knisley, C V; Reller, L B
Antigen detection methods may facilitate diagnosis of Giardia lamblia in stool specimens. As determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis and immunoblotting, G. lamblia cysts and trophozoites share several antigens, especially in the 65-kilodalton and 30- to 34-kilodalton regions. By using blind methods, we compared results obtained by counterimmunoelectrophoresis using cyst-immune rabbit serum and by enzyme-linked immunosorbent assay (ELISA) using trophozoite-immune rabbit serum with results obtained by microscopic examination of a preserved, concentrated, and permanently stained stool specimen. Results were similar when these three methods were used to examine 118 stool specimens from clinical microbiology laboratories (53 specimens with G. lamblia) and specimens from 239 day-care-center toddlers (39 specimens with G. lamblia). Compared with microscopy, we found, for counterimmunoelectrophoresis and ELISA, respectively: sensitivity, 88 versus 94%; specificity, 97 versus 95%; positive predictive value, 86 versus 76%; negative predictive value, 98 versus 97%; and concordance, 89%. The false-positive rate by ELISA was 24% (10 of 42) in day-care-center toddlers but only 3% (1 of 32) in healthy adults (P less than 0.04) as corroborated by microscopy. This discrepancy suggests that the ELISA may be more sensitive than microscopy, which is considered the reference standard, and that results may be dependent, in part, on the epidemiology of the infection in the study subjects. Images PMID:2715318
Novicki, Thomas J.
Blastomyces spp. antigen testing was evaluated over a 10-year period in an area where blastomycosis is endemic. Antigen testing was less sensitive than previously reported, but serial urine testing was useful in monitoring disease resolution or progression. Culture and cytopathology remain the gold standard for diagnosis and exclusion of this infection. PMID:26338856
Frost, Holly M; Novicki, Thomas J
Blastomyces spp. antigen testing was evaluated over a 10-year period in an area where blastomycosis is endemic. Antigen testing was less sensitive than previously reported, but serial urine testing was useful in monitoring disease resolution or progression. Culture and cytopathology remain the gold standard for diagnosis and exclusion of this infection.
Lee, Mi-Young; Shin, Meong-Cheol; Yang, Victor C.
Transcutaneous immunization refers to the topical application of antigens onto the epidermis. Transcutaneous immunization targeting the Langerhans cells of the skin has received much attention due to its safe, needle-free, and noninvasive antigen delivery. The skin has important immunological functions with unique roles for antigen-presenting cells such as epidermal Langerhans cells and dermal dendritic cells. In recent years, novel vaccine delivery strategies have continually been developed; however, transcutaneous immunization has not yet been fully exploited due to the penetration barrier represented by the stratum corneum, which inhibits the transport of antigens and adjuvants. Herein we review recent achievements in transcutaneous immunization, focusing on the various strategies for the enhancement of antigen delivery and vaccination efficacy. [BMB Reports 2013; 46(1): 17-24] PMID:23351379
Olesen, Scott W; Gurry, Thomas; Alm, Eric J
Fecal microbiota transplantation is a highly effective intervention for patients suffering from recurrent Clostridium difficile, a common hospital-acquired infection. Fecal microbiota transplantation's success as a therapy for C. difficile has inspired interest in performing clinical trials that experiment with fecal microbiota transplantation as a therapy for other conditions like inflammatory bowel disease, obesity, diabetes, and Parkinson's disease. Results from clinical trials that use fecal microbiota transplantation to treat inflammatory bowel disease suggest that, for at least one condition beyond C. difficile, most fecal microbiota transplantation donors produce stool that is not efficacious. The optimal strategies for identifying and using efficacious donors have not been investigated. We therefore examined the optimal Bayesian response-adaptive strategy for allocating patients to donors and formulated a computationally tractable myopic heuristic. This heuristic computes the probability that a donor is efficacious by updating prior expectations about the efficacy of fecal microbiota transplantation, the placebo rate, and the fraction of donors that produce efficacious stool. In simulations designed to mimic a recent fecal microbiota transplantation clinical trial, for which traditional power calculations predict [Formula: see text] statistical power, we found that accounting for differences in donor stool efficacy reduced the predicted statistical power to [Formula: see text]. For these simulations, using the heuristic Bayesian allocation strategy more than quadrupled the statistical power to [Formula: see text]. We use the results of similar simulations to make recommendations about the number of patients, the number of donors, and the choice of clinical endpoint that clinical trials should use to optimize their ability to detect if fecal microbiota transplantation is effective for treating a condition.
Edwards, C A; Bowen, J; Brydon, W G; Eastwood, M A
The colonic fermentation of ispaghula, a mucilage from Plantago ovata composed mainly of arabinoxylans, and its effects on stool output and caecal metabolism were investigated. Four groups of eight rats were fed on a basal diet (45 g non-starch polysaccharides/kg) for 28 d. The diet was then supplemented with ispaghula (g/kg; 0, 5, 15 or 50) for 28 d. Ispaghula increased stool dry weight and apparent wet weight but faecal water-holding capacity (amount of water held per g dry faecal material at 0.2 mPa) was unchanged. The extent of faecal drying in the metabolism cages was measured for rats fed on the basal diet and 50 g ispaghula/kg diet. At the faecal output levels encountered, only an 8% loss of wet weight would be predicted over 24 h and this was independent of diet. Faecal short-chain fatty acid (SCFA) concentration did not change but SCFA output increased. The molar proportion of SCFA as propionic acid increased and faecal pH was reduced. Values from pooled faecal samples suggested that approximately 50% of the ingested ispaghula was excreted by the 50 g ispaghula/kg diet group. Diaminopimelic acid (a constituent of bacterial cells) concentrations fell but output was unchanged indicating no change in bacterial mass. Similar changes were seen in the caecal contents but caecal pH and SCFA were unaffected. Ispaghula increased both caecal and colonic tissue wet weight and colonic length. Our results suggest that ispaghula is partly fermented in the rat caecum and colon, and loses its water-holding capacity. However, it is still an effective stool bulker and acts mainly by increasing faecal water by some unknown mechanism.
Hamric, J.P.; Morgan, K.L.
Gridlock, inertia, conflict, outrage, bureaucracy, obstruction, media sensationalizing, courts, and politicians. These are the things that characterize any attempt to implement a public policy today. It is worse today than it has ever been because the middle has dropped out of public opinion. We have today no consensus of public values. At Fernald, we have come to recognize that in order to achieve any success we must first build a public consensus about what success will look like. We do this through a three-part approach we call the three legged stool. It includes public information, management involvement, and person-to-person communication. Each of these elements is essential.
El-Moamly, Amal Abdul-Rasheed; El-Sweify, Mohamed Aly; Hafez, Mohamad Abdul
Lymphatic filariasis (LF) continues to be a major source of permanent disability and an impediment to socio-economic development in 73 countries where more than 1 billion people are at risk and over 120 millions are infected. The global drive to eliminate LF necessitates an increasing demand for valid, reliable and rapid diagnostic tests. This study aimed to assess the performance of the AD12 rapid format immunochromatographic test (ICT) to detect Wuchereria bancrofti circulating antigens, against the combined gold standard: TropBio Og4C3-ELISA (enzyme-linked immunosorbent assay) which detects circulating filarial antigen (CFA) and the nucleopore membrane filtration and microscopic examination. This prospective case-control study involved 647 asymptomatic migrant workers from filariasis-endemic countries. Of these specimens, 32 were positive for microfilaremia using the membrane filtration and microscopy, 142 positive by ELISA (of which 32 had microfilaremia), and 128 positive by the ICT (of which 31 had microfilaremia). The performance of the ICT was calculated against 32 true-positive and 90 true-negative cases. For the detection of CFA, the ICT had a sensitivity of 97% (95% confidence interval [CI] 91-103), specificity 100% (95% CI 100-100), Positive Predictive Value (PPV) 100% (95% CI 100-100), Negative Predictive Value (NPV) 99% (95% CI 97-101); and the total accuracy of the test was 99% (95% CI 98-101). The agreement between ICT and ELISA in detecting W. bancrofti antigens was excellent (kappa = 0.934; p = 0.000). In conclusion, the AD12-ICT test for the detection of W. bancrofti-CFA was sensitive and specific and comparable to the performance of ELISA. The ICT would be a useful additional test to facilitate the proposed strategies for control and elimination of LF. Because it is rapid, simple to perform, and does not require the use of special equipment, the ICT may be most appropriate in screening programs and in monitoring the possible risk of introducing
Christmann, Benjamin S.; Abrahamsson, Thomas R.; Bernstein, Charles N.; Duck, L. Wayne; Mannon, Peter J.; Berg, Göran; Björkstén, Bengt; Jenmalm, Maria C.; Elson, Charles O.
Background While immune responses directed against antigens from the intestinal microbiota are observed in certain diseases, the normal human adaptive immune response to intestinal microbiota is poorly defined. Objective Our goal was to assess the adaptive immune response to the intestinal microbiota present in 143 healthy adults and compare this response to the immune response observed in 52 children and their mothers at risk of having allergic disease. Methods Human serum was collected from adults and from children followed from birth to seven years of age, and the serum IgG response to a panel of intestinal microbiota antigens was assessed using a novel protein microarray. Results Nearly every individual tested, regardless of health status, had serum IgG that recognized a common set of antigens. Seroreactivity to the panel of antigens was significantly lower in atopic adults. Healthy infants expressed the highest level of IgG seroreactivity to intestinal microbiota antigens. This adaptive response developed between 6 and 12 months of age, and peaked around 2 years of age. Low IgG responses to certain clusters of microbiota antigens during infancy were associated with allergy development during childhood. Conclusions There is an observed perturbation of the adaptive response to antigens from the microbiota in allergic individuals. These perturbations are observable even in childhood, suggesting that optimal stimulation of the adaptive immune system by the microbiota may be needed to prevent certain immune-mediated diseases. PMID:26014812
Li, Yueyue; Jia, Xinyong; Liu, Baozhen; Qi, Yanmei; Zhang, Xiubin; Ji, Rui; Yu, Yanbo; Zuo, Xiuli; Li, Yanqing
Background Bristol stool form 1 and 2 is an important predictor of inadequate bowel preparation. Aim To evaluate the efficacy of supplemental preparation in bowel cleansing quality among patients with Bristol stool form 1 and 2, as well as the feasibility of tailored bowel preparation guided by Bristol stool form scale. Methods Patients with Bristol stool form 1 and 2 from 3 Chinese tertiary hospitals randomly received either 2 L PEG-ELP (group A) or 10 mg bisacodyl plus 2 L PEG-ELP (group B); patients with Bristol stool form 3 to 7 received 2 L PEG-ELP (group C) for bowel preparation. The primary endpoint is the rate of adequate bowel reparation for the whole colon. The adequate bowel preparation rate for separate colon segments, the polyp detection rate (PDR), tolerability, acceptability, sleeping quality and compliance were evaluated as secondary endpoints. Results 700 patients were randomized. In per-protocol analysis, patients in group B attained significantly higher successful preparation rate than group A (88.7% vs. 61.2%, p<0.001) and similar with group C (88.7% vs. 85.0%, p = 0.316). The PDR in group B was significantly higher than group A (43.2% vs. 25.7%, p<0.001). Acceptability was much higher in group B and C. Conclusions 10 mg bisacodyl plus 2 L PEG-ELP can significantly improve both bowel preparation quality and PDR in patients with Bristol stool form 1 and 2. Bristol stool form scale may be an easy and efficient guide for tailored bowel preparation before colonoscopy. PMID:28241037
Murinda, Shelton E; Nguyen, Lien T; Ivey, Susan J; Almeida, Raul A; Oliver, Stephen P
This paper describes a novel single-tube agar-based technique for motility enhancement and immunoimmobilization of Escherichia coli O157:H7. Motility indole ornithine medium and agar (0.4%, wt/vol) media containing either nutrient broth, tryptone broth, or tryptic soy broth (TSBA) were evaluated for their abilities to enhance bacterial motility. Twenty-six E. coli strains, including 19 O157:H7 strains, 1 O157:H(-) strain, and 6 generic E. coli strains, were evaluated. Test bacteria were stab inoculated in the center of the agar column, and tubes were incubated at 37 degrees C for 18 to 96 h. Nineteen to 24 of the 26 test strains (73.1 to 92.3%) were motile in the different media. TSBA medium performed best and was employed in subsequent studies of motility enhancement and H7 flagellar immunocapture. H7 flagellar antiserum (30 and 60 micro l) mixed with TSBA was placed as a band (1 ml) in the middle of an agar column separating the top (3-ml) and bottom (3-ml) agar layers. The top agar layer was inoculated with the test bacterial strains. The tubes were incubated at 37 degrees C for 12 to 18 h and for 18 to 96 h. The specificity and sensitivity of the H7 flagellar immunocapture tests were 75 and 100%, respectively. The procedure described is simple and sensitive and could be adapted easily for routine use in laboratories that do not have sophisticated equipment and resources for confirming the presence of H7 flagellar antigens. Accurate and rapid identification of H7 flagellar antigen is critical for the complete characterization of E. coli O157:H7, owing to the immense clinical, public health, and economic significance of this food-borne pathogen.
Michel, Pierre A; Kase, Julie A
Shiga toxin (Stx)-producing Escherichia coli (STEC) are associated with potentially serious illness in humans. STEC detection is often based on the presence of Stxs, Stx(1) and/or Stx(2), and intimin, encoded by the eae gene. A 2-year collection of stool broth cultures was tested for variants of stx(1), stx(2), and eae. Approximately 80% (138 of 174) were positive for stx(1) and/or stx(2), with stx(1) as the most prevalent (66%). Of the stx(1) variants, stx(1) was the most common (76%) followed by stx(1c) (22%). Analysis of stx(2)-positive isolates found 20 (53%) stx(2), 13 (34%) stx(2)/stx(2v-ha), 3 (8%) stx(2v-ha), 1 (3%) stx(2v-hb), and 1 (3%) stx(2d-activatable). Findings of stx(2)/stx(2v-ha) and stx(2d-activatable) are noteworthy given associations with hemolytic uremic syndrome and increased cytotoxicity, respectively. Of the Stx positive, 94 (68%) were eae positive with 31 (33%) eae(varepsilon1), 19 (20%) eae(gamma1), and 18 (19%) eae(beta1). A predominance of eae(varepsilon1) may suggest a new pathogenic significance because, reportedly, eae(beta1) is one of the most widespread variants.
Gioffré, A; Meichtri, L; Zumárraga, M; Rodríguez, R; Cataldi, A
A commercial kit intended for Taq polymerase inhibitor removal was tested to detect Shiga-toxigenic Escherichia coli (STEC) by polymersase chain reaction (PCR) directly from cattle fecal samples. Forty-five samples were analysed for the presence of stx genes. Results were compared to those obtained by two other methods: amplification of DNA purified by a non-commercial procedure (heat lysis protocol), and amplification of DNA from samples cultured in solid media, commonly used in our lab. Identical numbers of positive samples (33/45, 73 %) were obtained with the QIAamp DNA stool purification kit and the culturing procedure, suggesting an adequate removal of inhibitors that interfere in PCR amplification from the feces. Besides, the number of positive samples detected using DNA purified by the non-commercial protocol was lower, 25/39 (64%) than that achieved by using the kit. In conclusion, the use of the QIAamp DNA stool purification kit provided a rapid stx gene detection by PCR in bovine fecal samples.
Han, Sang Bong; Chang, Jiyoung; Shin, Sang Hyun; Park, Kang Gyun; Lee, Gun Dong; Park, Yong Gyu; Park, Yeon-Joon
We evaluated the performance of a new chromogenic medium for detection of Clostridium difficile, chromID C. difficile agar (CDIF; bioMérieux, France), by comparison with BBL C. difficile Selective Agar (CDSA; Becton Dickinson and Company, USA). After heat pre-treatment (80℃, 5 min), 185 diarrheal stool samples were inoculated onto the two media types and incubated anaerobically for 24 hr and 48 hr for CDIF and for 48 hr and 72 hr for CDSA. All typical colonies on each medium were examined by Gram staining, and the gram-positive rods confirmed to contain the tpi gene by PCR were identified as C. difficile. C. difficile was recovered from 36 samples by using a combination of the two media. The sensitivity with CDIF 48 hr was highest (100%) and was significantly higher than that with CDIF 24 hr (58.3%; P<0.001), because samples with a low burden of C. difficile tended to require prolonged incubation up to 48 hr (P<0.001). The specificity of CDIF 24 hr and CDIF 48 hr (99.3% and 90.6%, respectively) was significantly higher than that of CDSA 48 hr and CDSA 72 hr (72.5% and 67.1%, respectively; P<0.001). CDIF was effective for detecting C. difficile in heat-pretreated stool specimens, thus reducing unnecessary testing for toxin production in non-C. difficile isolates and turnaround time.
Kantarcioglu, A Serda; Kiraz, Nuri; Aydin, Ahmet
Autism spectrum disorder (ASD) is a general term for a group of complex neurodevelopmental disorders of brain development that limits a person's ability to function normally. Etiology has not been clearly defined up to date. However, gut microbiota and the bidirectional communication between the gastrointestinal tract and brain, the so-called microbiota-gut-brain axis, are hypothesized, which may be involved in the etiology of several mental disorders. Recent reports suggest that Candida, particularly Candida albicans, growth in intestines may cause lower absorption of carbohydrates and minerals and higher toxin levels which are thought to contribute autistic behaviors. The aim of this study was to identify the 3-year deposited yeasts isolated from stool samples of children with diagnosed or suspected ASD and to determine in vitro activity of nystatin and fluconazole against these isolates using Clinical Laboratory Standards Institute M27-A3 guidelines. A 17-year retrospective assessment was also done using our laboratory records. Among the species identified, intrinsically fluconazole-resistant Candida krusei (19.8 %) and Candida glabrata (14.8 %) with elevated MICs were remarkable. Overall, C. albicans (57.4 %) was the most commonly isolated species in 17 years. The species identification and/or antifungal susceptibility tests have to be performed using the strain isolated from stool sample, to select the appropriate antifungal agent, if antimycotic therapy is needed.
Gaillot, Olivier; Di Camillo, Patrick; Berche, Patrick; Courcol, René; Savage, Colette
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
Weigum, Shannon E; Xiang, Lichen; Osta, Erica; Li, Linying; López, Gabriel P
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.
Kim, Il-Hwan; Kwon, Hyuk-Joon; Park, Jae-Keun; Song, Chang-Seon; Kim, Jae-Hong
The PR8-based reverse genetics vector system is widely used to generate commercial vaccine strains, but the pathogenicity of PR8-derived recombinant viruses in mice hinders further immunological studies. In the present study, we generated PR8-derived H5N1 recombinant viruses, in which haemagglutinin (HA) and neuraminidase (NA) originated from a mouse-pathogenic H5N1 low pathogenic avian influenza virus (LPAIV), and the non-structural proteins (NS) and polymerase basic protein 2 (PB2) originated from different H9N2 LPAIVs. In contrast to the control H5N1 recombinant virus, harboring six internal genes from PR8, the NS and PB2 recombinant viruses did not cause body weight loss in mice. However, the NS recombinant virus replicated in the lungs of mice. It was more immunogenic than the PB2 recombinant virus to protect efficiently against a lethal challenge of a H5N1 highly pathogenic AIV with 89 and 88% amino acid identity in HA and NA, respectively. Therefore, the NS gene may be useful for generating nonpathogenic and immunogenic PR8-derived recombinant viruses for studies of antigenicity and protective efficacy in mice.
Ismael, Alaa Bassuny; Swelum, Ayman Abdel-Aziz; Mostafa, Salama A-H; Alhumiany, Abdel-Rahman A
Brucellosis, especially caused by Brucella melitensis, is considered the most-widespread zoonosis in the world, particularly in developing countries. This study was planned to develop an accurate test for diagnosis of ovine brucellosis using a specific hot saline extracted soluble Brucella melitensis periplasmic proteins (SBPPs). The efficacy of the latex agglutination test (LAT) using SBPPs compared to the Rose Bengal test (RBT), buffered plate agglutination test (BPAT), serum agglutination test (SAT), and an indirect enzyme-linked immunosorbent assay (i-ELISA) was evaluated in the field diagnosis of ovine brucellosis. The test performance was evaluated by estimating sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), disease prevalence (DP), positive likelihood ratio (PLR), and negative likelihood ratio (NLR) using test agreement and bacteriological culture in 1777 samples. The false-positive result was significantly (P ⩽0.05) lower in LAT than RBT, BPAT, SAT, and i-ELISA. With reference to test agreement, the Se, Sp, PPV, and PLR were highest (P ⩽0.05) in LAT 99.33%, 99.88%, 98.68%, and 827.25%, respectively. With reference to bacteriological culture, the LAT and i-ELISA tests showed a significant difference in Se with SAT. However, no significant difference in specificity was detected. The DP was 8.44% in the five tests. In conclusion, LAT using SBPPs of B. melitensis could be a suitable serodiagnostic field test for ovine brucellosis, with high sensitivity and specificity.
Dimitrov, D H; Estes, M K; Rangelova, S M; Shindarov, L M; Melnick, J L; Graham, D Y
Antigenically distinct rotaviruses, i.e., viruses morphologically identical to conventional rotaviruses by electron microscopy, yet lacking the common group antigen(s) detected by an enzyme-linked immunosorbent assay, were found in 2 of 51 fecal samples from Bulgarian infants with rotavirus gastroenteritis. These antigenically distinct viruses contained 11 segments of double-stranded RNA, but they demonstrated a unique RNA migration profile after electrophoresis of the genome RNA in polyacrylamide gels. This report confirms the presence of a new group of rotaviruses in humans. The significance of these viruses is currently unknown, and specific diagnostic tests must be developed for epidemiological studies to determine their role as human and veterinary pathogens and to evaluate their impact on proposed vaccine development programs. Images PMID:6307873
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Development and evaluation of a rapid, simple, and sensitive immunochromatographic assay to detect thermostable direct hemolysin produced by Vibrio parahaemolyticus in enrichment cultures of stool specimens.
Kawatsu, Kentaro; Ishibashi, Masanori; Tsukamoto, Teizo
Thermostable direct hemolysin (TDH) is considered to be a major virulence factor in Vibrio parahaemolyticus, and most cases of V. parahaemolyticus diarrhea in humans are caused by tdh gene-positive strains. In the present study, we developed an immunochromatographic assay to detect TDH (TDH-ICA) and evaluated the utility of TDH-ICA for the diagnosis of V. parahaemolyticus diarrhea. TDH-ICA allowed the detection of 0.2 ng/ml of TDH within 10 min. Fecal homogenates were spiked with various numbers of tdh-positive V. parahaemolyticus organisms, and their enrichment cultures were tested with TDH-ICA. The results of detection of TDH in the enrichment cultures by TDH-ICA were in accord with the results of recovery of the spiked V. parahaemolyticus organisms from the enrichment cultures by plating onto thiosulfate-citrate-bile salts-sucrose agar. When enrichment cultures of 217 stool specimens from patients with diarrhea were tested with TDH-ICA, the TDH-ICA results showed 100% sensitivity and specificity compared to the results of isolation of V. parahaemolyticus from the stool specimens by a conventional bacterial culture test. Since TDH-ICA was able to detect TDH in a fecal enrichment culture within 10 min, TDH-ICA testing of a fecal enrichment culture could be completed rapidly and easily within approximately 16 h, including incubation time for the fecal enrichment culture. These results indicate that TDH-ICA is a rapid, simple, and sensitive TDH detection method and that TDH-ICA testing of a fecal enrichment culture is useful as an adjunct to facilitate the early diagnosis of V. parahaemolyticus diarrhea.
Intestinal Parasite Profile in the Stool of HIV Positive Patients in relation to Immune Status and Comparison of Various Diagnostic Techniques with Special Reference to Cryptosporidium at a Tertiary Care Hospital in South India
Moorkoth, Anitha Puduvail; Mathew, Sheela
Acquired immunodeficiency syndrome and related opportunistic infections are a significant cause of morbidity and mortality in susceptible population. This study aims to negate the paucity of data regarding the relation between CD4 levels, prevalence of enteric parasites, and the outcome of treatment with HAART (highly active antiretroviral therapy) and Cotrimoxazole in Kerala, India. Multiple stool samples from 200 patients in a cross-sectional study were subjected to microscopy and Cryptosporidium stool antigen ELISA. Parasites were identified in 18 samples (9%). Cystoisospora and Cryptosporidium spp. were seen in 9 cases (4.5%) and 5 cases (2.5%), respectively. Microsporidium spores and Chilomastix mesnili cysts were identified in 1 case each (0.5% each). Seven cases of Cystoisospora diarrhoea recovered after treatment with Cotrimoxazole. Diarrhoea due to Cryptosporidium spp. in all 5 cases subsided after immune reconstitution with HAART. This study concludes that a positive association was seen between low CD4 count (<200 cells/μL) and overall parasite positivity (P value < 0.01). ELISA is a more sensitive modality for the diagnosis of Cryptosporidium diarrhoea. Chilomastix mesnili, generally considered a nonpathogen, may be a cause of diarrhoeal disease in AIDS. Immune reconstitution and Cotrimoxazole prophylaxis remain to be the best therapeutic approach in AIDS-related diarrhoea. PMID:27493988
Intestinal Parasite Profile in the Stool of HIV Positive Patients in relation to Immune Status and Comparison of Various Diagnostic Techniques with Special Reference to Cryptosporidium at a Tertiary Care Hospital in South India.
Kaniyarakkal, Vishnu; Mundangalam, Nizamuddin; Moorkoth, Anitha Puduvail; Mathew, Sheela
Acquired immunodeficiency syndrome and related opportunistic infections are a significant cause of morbidity and mortality in susceptible population. This study aims to negate the paucity of data regarding the relation between CD4 levels, prevalence of enteric parasites, and the outcome of treatment with HAART (highly active antiretroviral therapy) and Cotrimoxazole in Kerala, India. Multiple stool samples from 200 patients in a cross-sectional study were subjected to microscopy and Cryptosporidium stool antigen ELISA. Parasites were identified in 18 samples (9%). Cystoisospora and Cryptosporidium spp. were seen in 9 cases (4.5%) and 5 cases (2.5%), respectively. Microsporidium spores and Chilomastix mesnili cysts were identified in 1 case each (0.5% each). Seven cases of Cystoisospora diarrhoea recovered after treatment with Cotrimoxazole. Diarrhoea due to Cryptosporidium spp. in all 5 cases subsided after immune reconstitution with HAART. This study concludes that a positive association was seen between low CD4 count (<200 cells/μL) and overall parasite positivity (P value < 0.01). ELISA is a more sensitive modality for the diagnosis of Cryptosporidium diarrhoea. Chilomastix mesnili, generally considered a nonpathogen, may be a cause of diarrhoeal disease in AIDS. Immune reconstitution and Cotrimoxazole prophylaxis remain to be the best therapeutic approach in AIDS-related diarrhoea.
Mroczyńska, Marta; Galecka, Miroslawa; Szachta, Patrycja; Kamoda, Dorota; Libudzisz, Zdzislawa; Roszak, Dorota
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.
Johnson, Donald J; Martin, Liane R; Roberts, Katherine A
The purpose of this study was to compare the effectiveness of the QIAGEN QIAamp Stool Mini Kit against a standard phenolchloroform procedure for the extraction, quantitation, and STR-typing of human nuclear DNA from human feces. Stools from six subjects were sampled by swabbing and excision. Samples extracted with the QIAamp kit gave a wide range of DNA yields, whereas those extracted by the organic method yielded no DNA. DNA was not recovered from one subject's stools by either procedure. The QIAamp extracts were amplified with the Profiler Plus and COfiler kits, and PCR inhibition was observed with DNA extracts that were further concentrated. Substitution of water or TE-4 for the QIAamp elution buffer eliminated most, if not all, of the inhibition. A modified QIAamp procedure was used to extract thirty samples, which were subjected to one of five environmental conditions. DNA was recovered from all of these samples, and typing results were obtained on 93% of the samples.
Scansen, Kimberly A; Bonsu, Bema K; Stoner, Erin; Mack, Kathy; Salamon, Douglas; Leber, Amy; Marcon, Mario J
Rapid antigen testing of upper respiratory secretions collected with various swab types is often utilized for laboratory diagnoses of influenza virus infection. There are limited data on the effects of swab composition on test performance. This study compared the performance of the Quidel QuickVue Influenza A+B test on secretions from the anterior nares when a polyurethane foam swab was used for collection to that when a nylon flocked swab was used for collection. One hundred subjects who presented to a pediatric emergency department with symptoms suggestive of an influenza virus infection were recruited for the study. Foam and flocked swabs of the anterior nares were obtained from separate nares of each subject before a posterior nasopharyngeal swab was collected and placed into viral transport medium. The QuickVue test was performed directly on each swab type, and the results were compared to the results of reverse transcription-PCR (RT-PCR), direct fluorescent antibody (DFA) test, and viral culture performed on the transport medium. RT-PCR alone and DFA combined with culture were utilized as separate gold standards. There were 56 cases of influenza detected by RT-PCR; the QuickVue test was positive for 40 foam and 30 flocked swabs, for sensitivities of 71% and 54%, respectively (P = 0.01). Similarly, there were 49 influenza cases detected by DFA and/or culture; the QuickVue test was positive for 38 foam and 30 flocked swabs, for sensitivities of 78% and 61%, respectively (P = 0.13). This study suggests that polyurethane foam swabs perform better than nylon flocked swabs for the collection of secretions from anterior nares in the Quidel QuickVue Influenza A+B test.
TADESSE, Endale; WORKALEMAHU, Bereket; SHIMELIS, Techalew
SUMMARY Rapid diagnostic tests (RDTs) capable of detecting and differentiating Plasmodium species are needed in areas in which microscopy is unsuitable. This study was conducted to assess the diagnostic performance of the rapid test kit - SD BIOLINE Malaria Ag Pf/Pan(r) (05FK60) in an endemic area. Microscopy of Giemsa-stained blood films were performed to detect and estimate the Plasmodium density in malaria suspected patients. The performance of the SD BIOLINE Malaria Ag Pf/Pan test was evaluated using 272 Plasmodium-positive and 102 negative blood samples. The overall sensitivity of the SD BIOLINE Malaria Ag Pf/Pan test was 99.5% for P. falciparum and 92.6% for non-P. falciparum malaria infections. The respective specificity, PPV, and NPV of the test were 98.0, 98.4, and 99.0% for the diagnosis of P. falciparum, and 100.0 %, 100.0%, and 94.4% for non-P. falciparum species. The SD BIOLINE Malaria Ag Pf/Pan test showed an excellent performance in diagnosing Plasmodium infections in an endemic setting. Therefore, this point-of-care test could be used as an alternative to microscopy in places where P. falciparum is endemic and microscopy is unsuitable. PMID:27680164
Seyler, L; Lalvani, A; Collins, L; Goddard, L; Bowler, I C J W
Stools sent for culture from patients after three days of hospitalisation have a low yield (<1%) for bacterial enteric pathogens (BEP), excluding Clostridium difficile, and are expensive to process. A 'three-day rule' for rejection of specimens has previously been validated in adults. We evaluated a three-day rule for paediatric stool samples by retrospective review of all stool culture results from 1995 to 2002. Excluding C. difficile, yield for BEP in samples sent within three days following admission was 97/3751 (2.59%) compared with 3/1511 (0.2%) in samples sent more than three days after admission. The criteria for culture would have been met if the rule had been applied for these three samples. We prospectively evaluated potential savings if the rule were applied for both children and adults over a two-month period in 2000. Savings were greater for adults than for children. Of 490 stools from children, 38 (7.8%) samples did not meet the criteria for culture and of 206 stools from adult patients, 64 (31%) did not meet the criteria for culture. We implemented the rule between 1 March 2003 and 31 March 2006. A total of 14 439 stool samples were received from inpatients requesting culture for BEP, excluding C. difficile. Of these, 5744 (39.8%) were rejected because the criteria for culture were not met. This was estimated as an annual saving of 11,848 pounds to the Trust laboratory. If extrapolated to all NHS Trusts, the potential savings could be in the order of 1.18 million pounds annually.
Konta, Yoshimitsu; Kazama, Shinobu; Inaba, Manami; Imagawa, Toshifumi; Tohma, Kentaro; Saito, Mayuko; Suzuki, Akira; Oshitani, Hitoshi; Omura, Tatsuo
Selecting the best quantitative PCR assay is essential to detect human norovirus genome effectively from clinical and environmental samples because no cell lines have been developed to propagate this virus. The real-time PCR methods for noroviruses GI (4 assays) and GII (3 assays) were evaluated using wastewater (n = 70) and norovirus-positive stool (n = 77) samples collected in Japan between 2012 and 2013. Standard quantitative PCR assays recommended by the U.S. Environmental Protection Agency, International Organization for Standardization, and Ministry of Health, Labour and Welfare, Japan, together with recently reported assays were included. Significant differences in positive rates and quantification cycles were observed by non-parametric analysis. The present study identifies the best assay for norovirus GI and GII to amplify norovirus genomes efficiently. PMID:27525654
Williams, Candace L.; Dill-McFarland, Kimberly A.; Vandewege, Michael W.; Sparks, Darrell L.; Willard, Scott T.; Kouba, Andrew J.; Suen, Garret; Brown, Ashli E.
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
Naas, Thierry; Ergani, Ayla; Carrër, Amélie; Nordmann, Patrice
An in-house quantitative real-time PCR (qPCR) assay using TaqMan chemistry has been developed to detect NDM-1 carbapenemase genes from bacterial isolates and directly from stool samples. The qPCR amplification of bla(NDM-1) DNA was linear over 10 log dilutions (r(2) = 0.99), and the amplification efficiency was 1.03. The qPCR detection limit was reproducibly 1 CFU, or 10 plasmid molecules, and there was no cross-reaction with DNA extracted from several multidrug-resistant bacteria harboring other β-lactam resistance genes. Feces spiked with decreasing amounts of enterobacterial isolates producing NDM-1 were spread on ChromID ESBL and on CHROMagar KPC media and were subjected to the qPCR. The limits of carbapenem-resistant bacterial detection from stools was reproducibly 1 × 10(1) to 3 × 10(1) CFU/100 mg feces with ChromID ESBL medium. The CHROMagar KPC culture medium had higher limits of detection (1 × 10(1) to 4 × 10(3) CFU/ml), especially with bacterial isolates having low carbapenem MICs. The limits of detection with the qPCR assay were reproducibly below 1 × 10(1) CFU/100 mg of feces by qPCR assay. Samples spiked with NDM-1-negative bacteria were negative by qPCR. The sensitivity and specificity of the bla(NDM-1) qPCR assay on spiked samples were 100% in both cases. Using an automated DNA extraction system (QIAcube system), the qPCR assay was reproducible. The use of qPCR is likely to shorten the time for bla(NDM-1) detection from 48 h to 4 h and will be a valuable tool for outbreak follow-up in order to rapidly isolate colonized patients and assign them to cohorts.
Klein, B S; Jones, J M
competition tests, MAbs specific for the 25-residue repeat abolished binding of anti-A antiserum to A antigen. In antigen inhibition tests, the recombinant repeat abolished binding of anti-A antiserum to A antigen. These results demonstrate that the repeat is the major site of antibody recognition of both WI-1 and A antigen and that the recombinant, nonglycosylated peptide could replace either native antigen in formatting better diagnostic tests for blastomycosis. Moreover, they suggest that producing fungal protein antigens as nonglycosylated peptides in a procaryotic expression system may circumvent problems of antigen cross-reactivity that are due to posttranslational modification. Images PMID:7520423
Hunsperger, Elizabeth A.; Yoksan, Sutee; Buchy, Philippe; Nguyen, Vinh Chau; Sekaran, Shamala Devi; Enria, Delia A.; Vazquez, Susana; Cartozian, Elizabeth; Pelegrino, Jose L.; Artsob, Harvey; Guzman, Maria G.; Olliaro, Piero; Zwang, Julien; Guillerm, Martine; Kliks, Susie; Halstead, Scott; Peeling, Rosanna W.; Margolis, Harold S.
Commercially available diagnostic test kits for detection of dengue virus (DENV) non-structural protein 1 (NS1) and anti-DENV IgM were evaluated for their sensitivity and specificity and other performance characteristics by a diagnostic laboratory network developed by World Health Organization (WHO), the UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR) and the Pediatric Dengue Vaccine Initiative (PDVI). Each network laboratory contributed characterized serum specimens for the panels used in the evaluation. Microplate enzyme-linked immunosorbent assay (ELISA) and rapid diagnostic test (RDT formats) were represented by the kits. Each ELISA was evaluated by 2 laboratories and RDTs were evaluated by at least 3 laboratories. The reference tests for IgM anti-DENV were laboratory developed assays produced by the Armed Forces Research Institute for Medical Science (AFRIMS) and the Centers for Disease Control and Prevention (CDC), and the NS1 reference test was reverse transcriptase polymerase chain reaction (RT-PCR). Results were analyzed to determine sensitivity, specificity, inter-laboratory and inter-reader agreement, lot-to-lot variation and ease-of-use. NS1 ELISA sensitivity was 60–75% and specificity 71–80%; NS1 RDT sensitivity was 38–71% and specificity 76–80%; the IgM anti-DENV RDTs sensitivity was 30–96%, with a specificity of 86–92%, and IgM anti-DENV ELISA sensitivity was 96–98% and specificity 78–91%. NS1 tests were generally more sensitive in specimens from the acute phase of dengue and in primary DENV infection, whereas IgM anti-DENV tests were less sensitive in secondary DENV infections. The reproducibility of the NS1 RDTs ranged from 92-99% and the IgM anti-DENV RDTs from 88–94%. PMID:25330157
Hunsperger, Elizabeth A; Yoksan, Sutee; Buchy, Philippe; Nguyen, Vinh Chau; Sekaran, Shamala Devi; Enria, Delia A; Vazquez, Susana; Cartozian, Elizabeth; Pelegrino, Jose L; Artsob, Harvey; Guzman, Maria G; Olliaro, Piero; Zwang, Julien; Guillerm, Martine; Kliks, Susie; Halstead, Scott; Peeling, Rosanna W; Margolis, Harold S
Commercially available diagnostic test kits for detection of dengue virus (DENV) non-structural protein 1 (NS1) and anti-DENV IgM were evaluated for their sensitivity and specificity and other performance characteristics by a diagnostic laboratory network developed by World Health Organization (WHO), the UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR) and the Pediatric Dengue Vaccine Initiative (PDVI). Each network laboratory contributed characterized serum specimens for the panels used in the evaluation. Microplate enzyme-linked immunosorbent assay (ELISA) and rapid diagnostic test (RDT formats) were represented by the kits. Each ELISA was evaluated by 2 laboratories and RDTs were evaluated by at least 3 laboratories. The reference tests for IgM anti-DENV were laboratory developed assays produced by the Armed Forces Research Institute for Medical Science (AFRIMS) and the Centers for Disease Control and Prevention (CDC), and the NS1 reference test was reverse transcriptase polymerase chain reaction (RT-PCR). Results were analyzed to determine sensitivity, specificity, inter-laboratory and inter-reader agreement, lot-to-lot variation and ease-of-use. NS1 ELISA sensitivity was 60-75% and specificity 71-80%; NS1 RDT sensitivity was 38-71% and specificity 76-80%; the IgM anti-DENV RDTs sensitivity was 30-96%, with a specificity of 86-92%, and IgM anti-DENV ELISA sensitivity was 96-98% and specificity 78-91%. NS1 tests were generally more sensitive in specimens from the acute phase of dengue and in primary DENV infection, whereas IgM anti-DENV tests were less sensitive in secondary DENV infections. The reproducibility of the NS1 RDTs ranged from 92-99% and the IgM anti-DENV RDTs from 88-94%.
Akaishi, Yu; Matsumoto, Tetsuya; Harada, Yoshimi; Hirayama, Yoji
As the characteristics and accuracy of rapid influenza detection tests (RIDTs) vary, the development of a high-performance RIDT has been eagerly anticipated. In this study, the new RIDT GOLD SIGN FLU and the existing RIDT Quick Navi-Flu were evaluated in terms of detecting the antigens of influenza viruses A and B in Japanese adults with influenza-like symptoms. The study was performed from December 2013 to March 2014. Among the 123 patients from whom nasopharyngeal swab specimens were collected, 59 tested positive by viral isolation as the gold standard method (influenza A, n=38; influenza B, n=21). For GOLD SIGN FLU, the sensitivities were 73.7% and 81.0%, and the specificities were 97.6% and 98.0% for influenza A and B, respectively. For Quick Navi-Flu, the sensitivities were 86.8% and 85.7%, and the specificities were 98.8% and 100% for influenza A and B, respectively. The time to the appearance of the line on the test strip was less than 3min for influenza A and less than 2min for influenza B with both RIDTs in more than 90% of cases. GOLD SIGN FLU was useful for diagnosing influenza A, and the result was readily available for influenza B particularly among adult patients. Quick Navi-Flu showed better sensitivities and specificities than GOLD SIGN FLU.
Almeida-Paes, Rodrigo; Bailão, Alexandre Melo; Pizzini, Cláudia Vera; Reis, Rosani Santos; Soares, Célia Maria de Almeida; Peralta, José Mauro; Gutierrez-Galhardo, Maria Clara; Zancopé-Oliveira, Rosely Maria
Sporotrichosis is a subcutaneous mycosis diagnosed by isolation of the fungus in culture. Serological tests for help in diagnosis in general do not use purified or recombinant antigens, because there is a paucity of described immunoreactive proteins, especially for the new described Sporothrix species, such as Sporothrix brasiliensis. This study aims to characterise antigens from S. brasiliensis and verify their application in serodiagnosis of sporotrichosis. An immunoblot assay allied with computer-based analysis was used to identify putative antigenic molecules in a cell-free extracts of both morphological phases of this fungus, and to delineate antigenic polymorphism among seven S. brasiliensis isolates and one S. schenckii Brazilian strain. The mycelial and yeast phase of the fungus originated 14 and 23 reactive bands, respectively, which were variable in intensity. An 85 kDa antigen, verified in the yeast phase of the fungus, was observed in all strains used and the immunodominant protein was identified. This protein, however, cross-react with serum samples from patients infected with other pathogens. The results show that the S. brasiliensis cell-free antigen extract is a single and inexpensive source of antigens, and can be applied on the sporotrichosis serodiagnosis.
Rogala, Patrycja; Jabłońska-Wawrzycka, Agnieszka; Kazimierczuk, Katarzyna; Borek, Agnieszka; Błażejczyk, Agnieszka; Wietrzyk, Joanna; Barszcz, Barbara
A mononuclear compound of the general formula [(η6-p-cymene)RuIICl(2,2‧-PyBIm)]PF6 has been synthesized from a bidentate N,N-donor ligand, viz. 2,-(2‧-pyridyl)benzimidazole (2,2‧-PyBIm) and the corresponding chloro-complex [(η6-p-cymene)Ru(μ-Cl)Cl]2 (precursor). The isolated coordination compound was characterized by IR, UV-vis and 1H, 13C NMR spectroscopies. The single crystal X-ray analysis of the complex reveals that the asymmetric part of the unit cell consists of two symmetrically independent, [(η6-p-cymene)RuCl(2,2‧-PyBIm)]+ cationic complexes. Each cation exhibits a pseudo-octahedral three-legged piano-stool geometry, in which three "legs" are occupied by one chloride ion and two nitrogen donor atoms of the chelating ligand 2,2‧-PyBIm. The Hirshfeld surface analysis of obtained complex was determined, too. The ionic nature of the compound is identified by a strong band at around 830 cm-1 due to the νP-F stretching mode of the PF6- counter ion. The electronic spectrum of this monomeric complex displays high intensity bands in the ultraviolet region assignable to π→π*/n→π* transitions, as well as a band attributable to the metal-to-ligand charge transfer (MLCT) dπ(Ru)→π*(L) transition. Additionally, the complex has been screened for its cytotoxicity against three human cancer lines: non-small cell lung carcinoma (A549), colon adenocarcinoma (HT29) and breast adenocarcinoma (MCF-7) as well as normal mice fibroblast cells (BALB/3T3). The complex demonstrated a moderate antiproliferative activity against the cell lines tested.
Sadaka, H A; Gaafar, M R; Mady, R F; Hezema, N N
This study was designed to evaluate ImmunoCard STAT Cryptosporidium/Giardia rapid assay and ELISA copro-antigen assays in detecting Giardia lamblia and Cryptosporidium species in fecal samples in comparison to microscopy. Both ImmunoCard STAT and ELISA assays were evaluated with 90 stool specimens that were tested by the standard ova and parasite examination including staining with both iron hematoxylin stain and modified Ziehl Neelson stains. Counting the number of Giardia cysts and Cryptosporidia oocysts in the positive stool samples was done in order to quantify the lower limit of parasite number that was able to be detected by all included assays. Both ImmunoCard STAT and ELISA assays were compared on the basis of the attributes which are number of detected cases, sensitivity, specificity, time required for the procedure and screening, ease of performance and interpretation, and cost. Microscopic examination revealed that 13.3% of the samples were positive for Giardia and 2.2% for Cryptosporidium. By ELISA, 16.7% of the samples were infected with Giardia and 3.3% with Cryptosporidium, while by ImmunoCard STAT, 17.8 and 4.45% of the samples were positive for Giardia and Cryptosporidium, respectively. There is no statistically significant difference between the results of ELISA and ImmunoCard STAT assays. The lowest concentration detected in the stool samples was 10.50 ± 1.05 Giardia cysts and 2.83 ± 1.72 Cryptosporidium oocysts. The ImmunoCard STAT was extremely easy to read, thus requiring much less time, but its cost was much higher than ELISA. We concluded that although the overall ranking of both assays was high, the ImmunoCard STAT rapid assay was a more desirable test despite its higher cost.
Worrell, Caitlin M.; Bartoces, Monina; Karanja, Diana M. S.; Ochola, Elizabeth A.; Matete, Daniel O.; Mwinzi, Pauline N. M.; Montgomery, Susan P.; Secor, W. Evan
Financial resources tend to be limited in schistosomiasis endemic areas, forcing program managers to balance financial and scientific considerations when selecting detection assays. Therefore, we compared the costs of using single stool Kato-Katz, triplicate stool Kato-Katz, and point-of-contact circulating cathodic antigen (POC-CCA) assays for the detection of Schistosoma mansoni infection. Economic and financial costs were estimated from the viewpoint of a schistosomiasis control program using the ingredients approach. Costs related to specimen collection, sample processing and analysis, and treatment delivery were considered. Analysis inputs and assumptions were tested using one-way and two-way sensitivity analysis. The total per-person cost of performing the single Kato-Katz, triplicate Kato-Katz, and POC-CCA was US$6.89, US$17.54, and US$7.26, respectively. Major cost drivers included labor, transportation, and supplies. In addition, we provide a costing tool to guide program managers in evaluating detection costs in specific settings, as costs may vary temporally and spatially. PMID:25870422
Beletskaya, L V; Gnezditskaya, E V
The use of sera containing antibodies to tissue-specific antigens of highly specialized organs (skeletal muscles, heart, skin, excretory glands) enabled us to detect, by immunofluorescence, cells capable of synthesizing analogous antigens (i.e. hetero-organic thymus antigens) in human and animal thymus. Detection of hetero-organic antigens in the thymus is the basis for the hypothesis that natural immunological tolerance to tissue self antigens is formed within the thymus in the course of T-lymphocyte maturation, with thymus antigens taking part in the process.
Yaita, Kenichiro; Aoki, Kotaro; Suzuki, Takumitsu; Nakaharai, Kazuhiko; Yoshimura, Yukihiro; Harada, Sohei; Ishii, Yoshikazu; Tachikawa, Natsuo
Objective Travel overseas has recently been considered a risk factor for colonization with drug-resistant bacteria. The purpose of this study was to establish the epidemiology and risk factors associated with the acquisition of drug-resistant bacteria by Japanese travelers. Methods Between October 2011 and September 2012, we screened the stools of 68 Japanese returning travelers for extended-spectrum β-lactamase (ESBL) producing Escherichia coli. All specimens were sampled for clinical reasons. Based on the results, the participants were divided into an ESBL-producing E. coli positive group (18 cases; 26%) and an ESBL-producing E. coli negative group (50 cases; 74%), and a case-control study was performed. Microbiological analyses of ESBL-producing strains, including susceptibility tests, screening tests for metallo-β-lactamase, polymerase chain reaction amplification and sequencing of blaCTX-M genes, multilocus sequence typing, and whole genome sequencing, were also conducted. Results In a univariate comparison, travel to India was a risk factor (Odds Ratio 13.6, 95% Confidence Interval 3.0–75.0, p<0.0001). There were no statistical differences in the characteristics of the travel, such as backpacking, purpose of travel, interval between travel return and sampling stool, and duration of travel. Although 10 of 13 analyzed strains (77%) produced CTX-M-15, no ST131 clone was detected. Conclusion We must be aware of the possibilities of acquiring ESBL-producing E. coli during travel in order to prevent the spread of these bacteria not only in Japan but globally. PMID:24836896
Bonten, M J; Nathan, C; Weinstein, R A
The recovery of antibiotic-susceptible and -resistant aerobic Gram-negative bacilli from stool specimens and from mock rectal swabs after freezing (-20 degrees C) for as long as 4 weeks was studied using three preservatives: Cary-Blair (CB) transport medium, buffered glycerol saline (BGS), and Para Pak C&S solution (CS). In addition, the recovery of enterococci from rectal swabs was investigated after storage of swabs in Stuart's transport media at 4 degrees C as long as 4 weeks. The log10 decreases in bacterial counts from seeded stool suspensions frozen in BGS were 0.64 (i.e., fourfold) and 1.16 after 1 and 4 weeks, respectively, which were significantly less (p < .05) than 1 and 4 week decreases following freezing in CB (1.57 and 2.85) or in CS (1.50 and 2.45). The recovery of Gram-negative bacilli from patients' rectal swabs preserved in BGS was consistent with the results of the experiments with seeded stool suspensions. There was no detectable decrease in recovery of enterococci from rectal swabs stored at 4 degrees C. BGS performed well as a preservative for freezing stool specimens or rectal swabs for later recovery of nosocomial Gram-negative bacilli; enterococci survived well in refrigerated rectal swab specimens.
Kim, A Reum; Chung, Hee Chun; Kim, Hye Kwon; Kim, Eun Ok; Nguyen, Van Giap; Choi, Min Gyung; Yang, Hye Jung; Kim, Jung Ah; Park, Bong Kyun
Porcine circular single-stranded DNA viruses have been just identified from swine feces in Korea. This virus was mentioned as bovine stool-associated circular DNA virus (BoSCV)-like virus discovered from porcine stools. However, the thorough characteristics of the virus were not identified. Therefore, this research focuses on finding a full genome sequence and analyzing the genetic features of the virus. The virus, now called porcine stool-associated circular DNA virus in Korea (PoSCV Kor), consists of 2,589 bases forming circular structure. It has two major ORFs inversely encoding replicase and capsid protein, with each stem-loop structure between 5' ends and 3' ends of the two putative ORFs. This characteristics is the same as PoSCV in New Zealand, but different from chimpanzee stool-associated circular virus (ChiSCVs) and BoSCV, which have one stem-loop structure. Therefore, it would be sure that PoSCV Kor is very similar to PoSCV in respect to the genetic aspect; the same number of nucleotide bases and the amino acid identity of replicase and capsid protein (96 and 93 %, respectively). This fact could be certified through the finding that PoSCV Kor and PoSCV are in the same cluster by phylogenetic analysis based on the comparison with full-sequences of other circular ssDNA viruses.
Lowe, Adam; Lin, Margaret
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…
Li, You-Mei; Liu, Xue-Yuan
We and others have reported that the serum procalcitonin (PCT) level has a demonstrative role in predicting the long-term mortality after acute ischemic stroke (AIS) in Chinese population. Nevertheless, the underlying mechanisms remain ill-defined. In the current study, we further detected a close association of stool microRNA-637 (miR-637) levels with the long-term mortality after AIS in Chinese population. Moreover, the serum PCT and stool miR-637 levels appeared to be inversely correlated. AIS patients with lower levels of stool miR-637 appeared to predict more severe mortality in the long-term. Since PCT has been shown to be mainly produced by the neuroendocrine cells in the intestine, we used an intestine neuroendocrine cell line to study the relationship between miR-637 and PCT. Bioinformatics analyses showed that miR-637 targeted the 3’-UTR of PCT mRNA to inhibit its translation, and thus the levels of PCT protein production and secretion, which was proved by luciferase reporter assay. Together, our data reveal that the molecular mechanisms underlying application of serum PCT and stool miR-637 in prognosis of AIS, in which miR-637 in intestine neuroendocrine cells may be reduced during AIS to allow more PCT to be released into serum to be detected. PMID:27830008
Rockstroh, Jürgen Kurt; Feld, Jordan J; Chevaliez, Stéphane; Cheng, Kevin; Wedemeyer, Heiner; Sarrazin, Christoph; Maasoumy, Benjamin; Herman, Christine; Hackett, John; Cohen, Daniel E; Dawson, George J; Cloherty, Gavin; Pawlotsky, Jean-Michel
In light of the advances in HCV therapy, simplification of diagnosis confirmation, pre- treatment diagnostic workup and treatment monitoring is required to ensure broad access to interferon-free therapies. HCV core antigen (HCV cAg) testing is rapid, giving results in approximately 60min, and less expensive than HCV RNA methods. While extensive data on the analytical performance of HCV cAg relative to RNA or comparisons in longitudinal studies of patients on interferon based (response guided) therapy there is very limited data on the relative performance of HCV cAg in diagnosis and monitoring patients receiving all-oral interferon free regimens. Furthermore, there is no data in the literature that describes the specificity of HCV cAg in patients with resolved HCV infection i.e. anti-HCV positive/HCV RNA negative. In this study a total of 1201 plasma samples from the 411 HCV genotype 1 subjects with a HCV RNA viral load >50,000IU/ml who enrolled in a clinical trial with ombitasvir, ritonavir-boosted paritaprevir and dasabuvir, with or without ribavirin were retrospectively tested in a blinded fashion with HCV cAg test and results were compared to HCV RNA levels. The specificity of the HCV cAg test was also evaluated in anti-HCV positive but HCV RNA negative samples. Overall concordance between HCV cAg and HCV RNA was 98.6% while concordance in pre-treatment samples was 99.5% (409/411; n=2 HCV RNA pos. with viral loads>3 Mill IU/ml but HCV cAg neg.) and 99.24% in post treatment week 12 samples (391/394; n=2 HCV RNA pos.<25IU/ml and n=1 HCV RNA pos. 2180IU/ml). Specificity in anti-HCV positive HCV RNA negative samples tested was 100%.
Lampman, Richard L; Krasavin, Nina M; Szyska, Michael; Novak, Robert J
Mosquitoes identified as female Culex (Culex) species, primarily mixtures or uniform batches of Culex pipiens and Culex restuans, were collected daily from gravid traps by 2 mosquito abatement districts (MADs) in Cook County, Illinois. From 2002 through 2004, batches (pools) of mosquitoes were tested by the MADs for West Nile virus (WNV) by using VecTest WNV antigen assays and the same samples were retested, usually within 1-2 wk, for WNV RNA by the TaqMan reverse transcriptase polymerase chain reaction (RT-PCR). There were 952 TaqMan-positive pools out of 3,953 pools over the 3 years, and about one half of that number were VecTest-positive. The difference between the 2 detection assays varied between and within years. The VecTest assays detected about 57% and 69% of the TaqMan RT-PCR-positive pools from Des Plaines Valley MAD and Northwest MAD in 2002, but only about 40% and 46% in 2003, and 36% and 55% in 2004, respectively. Based on a subset of the 2004 data, a linear relationship was found between VecTest detection of WNV and TaqMan cycle threshold between 18 and 28 cycles. A temporal decrease in the difference between the 2 assays was observed in 2003 and 2004, which we conjecture is due, at least partially, to a seasonal decline in the proportion of recently infected mosquitoes. This trend was not observed in 2002 because infection rates indicated a high likelihood of more than 1 infected mosquito per pool at the peak of transmission. Unlike a previous study, the 95% confidence intervals of infection rates based on the 2 detection methods did not always overlap. The highest infection rates occurred in 2002 when mean monthly temperatures were above average.
Butterfield, Lisa H
A wide variety of tumor antigens have been targeted in cancer immunotherapy studies. Traditionally, the focus has been on commonly overexpressed antigens shared across many patients and/or tumor types. As the field has progressed, the identity of human tumor rejection antigens has broadened. Immunologic monitoring of clinical trials has slowly elucidated candidate biomarkers of immune response and clinical response, and conversely, of immune dysfunction and suppression. We have utilized MART-1/Melan-A in our melanoma studies and observed a high frequency of immune responses and several significant clinical responses in patients vaccinated with this melanosomal protein. Alpha-fetoprotein is a shared, overexpressed tumor antigen and secreted glycoprotein that we have tested in hepatocellular cancer vaccines. Our recent studies have identified immunosuppressive and immune-skewing activities of this antigen. The choice of target antigen and its form can have unexpected effects.
Infectious agents or their constituent parts (antigens or nucleic acids) can be detected in fresh, frozen, or fixed tissues or other specimens, using a variety of direct or indirect assays. The assays can be modified to yield the greatest sensitivity and specificity but in most cases a particular m...
Busch, R K; Busch, H
In an extension of previous studies on the antigens in rat liver nucleoli (R. K. Busch, R. C. Reddy, D. H. Henning, and H. Busch, Proc. Soc. Exp. Biol. Med. 160, 185 (1979); R. K. Busch and H. Busch, Tumori 63, 347 (1977); F. M. Davis, R. K. Busch, L. C. Yeoman, and H. Busch, Cancer Res. 38, 1906 (1978), rabbit antibodies were elicited to human liver nucleoli isolated by the sucrose--Mg2+ method (10). Fluorescent nucleoli were found in liver cryostat sections treated with rabbit anti-human liver nucleolar antibodies followed by fluorescein-conjugated goat anti-rabbit antibodies. In HeLa cells, fluorescence was distributed throughout the nucleus and in a nuclear network but was not localized to the nucleolus. In placental cryostat sections, an overall nuclear fluorescence was observed with some localization to nucleoli. Immunodiffusion analysis revealed two immunoprecipitin bands which appeared to be liver specific. Other immunoprecipitin bands were common to liver, placenta, and HeLa nuclear extracts. Rocket immunoelectrophoresis revealed two liver-specific antigens, one migrating to the cathode and the other to the anode Other rockets exhibited identity to antigens of other nuclear extracts. These results demonstrate the presence of human liver nucleolar-specific antigens which were not found in the HeLa and placental cells.
Hudrisier, Denis; Neyrolles, Olivier
The importance of CD4 T lymphocytes in immunity to M. tuberculosis is well established; however, how dendritic cells activate T cells in vivo remains obscure. In this issue of Cell Host & Microbe, Srivastava and Ernst (2014) report a mechanism of antigen transfer for efficient activation of antimycobacterial T cells.
Infectious agents or their constituent parts (antigens or nucleic acids) can be detected in fresh, frozen, or fixed tissue using a variety of direct or indirect assays. The assays can be modified to yield the greatest sensitivity and specificity but in most cases a particular methodology is chosen ...
Havill, Nancy L.; Boyce, John M.
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
Webb, Andrew L.; Boras, Valerie F.; Kruczkiewicz, Peter; Selinger, L. Brent
Arcobacter butzleri has been linked to enteric disease in humans, but its pathogenicity and epidemiology remain poorly understood. The lack of suitable detection methods is a major limitation. Using comparative genome analysis, we developed PCR primers for direct detection and quantification of A. butzleri DNA in microbiologically complex matrices. These primers, along with existing molecular and culture-based methods, were used to detect A. butzleri and enteric pathogens in stools of diarrheic and nondiarrheic people (n = 1,596) living in southwestern Alberta, Canada, from May to November 2008. In addition, quantitative PCR was used to compare A. butzleri densities in diarrheic and nondiarrheic stools. Arcobacter butzleri was detected more often by PCR (59.6%) than by isolation methods (0.8%). Comparison by PCR-based detection found no difference in the prevalence of A. butzleri between diarrheic (56.7%) and nondiarrheic (45.5%) individuals. Rates of detection in diarrheic stools peaked in June (71.1%) and October (68.7%), but there was no statistically significant correlation between the presence of A. butzleri and patient age, sex, or place of habitation. Densities of A. butzleri DNA in diarrheic stools (1.6 ± 0.59 log10 copies mg−1) were higher (P = 0.007) than in nondiarrheic stools (1.3 ± 0.63 log10 copies mg−1). Of the 892 diarrheic samples that were positive for A. butzleri, 74.1% were not positive for other bacterial and/or viral pathogens. The current study supports previous work suggesting that A. butzleri pathogenicity is strain specific and/or dependent on other factors, such as the level of host resistance. PMID:26865686
Ansell, Juliet; Butts, Christine A; Paturi, Gunaranjan; Eady, Sarah L; Wallace, Alison J; Hedderley, Duncan; Gearry, Richard B
The worldwide growth in the incidence of gastrointestinal disorders has created an immediate need to identify safe and effective interventions. In this randomized, double-blind, placebo-controlled study, we examined the effects of Actazin and Gold, kiwifruit-derived nutritional ingredients, on stool frequency, stool form, and gastrointestinal comfort in healthy and functionally constipated (Rome III criteria for C3 functional constipation) individuals. Using a crossover design, all participants consumed all 4 dietary interventions (Placebo, Actazin low dose [Actazin-L] [600 mg/day], Actazin high dose [Actazin-H] [2400 mg/day], and Gold [2400 mg/day]). Each intervention was taken for 28 days followed by a 14-day washout period between interventions. Participants recorded their daily bowel movements and well-being parameters in daily questionnaires. In the healthy cohort (n = 19), the Actazin-H (P = .014) and Gold (P = .009) interventions significantly increased the mean daily bowel movements compared with the washout. No significant differences were observed in stool form as determined by use of the Bristol stool scale. In a subgroup analysis of responders in the healthy cohort, Actazin-L (P = .005), Actazin-H (P < .001), and Gold (P = .001) consumption significantly increased the number of daily bowel movements by greater than 1 bowel movement per week. In the functionally constipated cohort (n = 9), there were no significant differences between interventions for bowel movements and the Bristol stool scale values or in the subsequent subgroup analysis of responders. This study demonstrated that Actazin and Gold produced clinically meaningful increases in bowel movements in healthy individuals.
McCluskey, D R; Maxwell, A P; Watt, L
We report five cases of Wegener's granulomatosis all of whom had clinical and histological evidence of disease activity at presentation and in whom autoantibodies to neutrophil antigens were detected. This test may prove useful for the diagnosis of this serious condition and help to monitor disease activity during treatment. PMID:3068870
Miftahussurur, Muhammad; Yamaoka, Yoshio
Among the methods developed to detect H. pylori infection, determining the gold standard remains debatable, especially for epidemiological studies. Due to the decreasing sensitivity of direct diagnostic tests (histopathology and/or immunohistochemistry [IHC], rapid urease test [RUT], and culture), several indirect tests, including antibody-based tests (serology and urine test), urea breath test (UBT), and stool antigen test (SAT) have been developed to diagnose H. pylori infection. Among the indirect tests, UBT and SAT became the best methods to determine active infection. While antibody-based tests, especially serology, are widely available and relatively sensitive, their specificity is low. Guidelines indicated that no single test can be considered as the gold standard for the diagnosis of H. pylori infection and that one should consider the method's advantages and disadvantages. Based on four epidemiological studies, culture and RUT present a sensitivity of 74.2–90.8% and 83.3–86.9% and a specificity of 97.7–98.8% and 95.1–97.2%, respectively, when using IHC as a gold standard. The sensitivity of serology is quite high, but that of the urine test was lower compared with that of the other methods. Thus, indirect test validation is important although some commercial kits propose universal cut-off values. PMID:26904678
Miftahussurur, Muhammad; Yamaoka, Yoshio
Among the methods developed to detect H. pylori infection, determining the gold standard remains debatable, especially for epidemiological studies. Due to the decreasing sensitivity of direct diagnostic tests (histopathology and/or immunohistochemistry [IHC], rapid urease test [RUT], and culture), several indirect tests, including antibody-based tests (serology and urine test), urea breath test (UBT), and stool antigen test (SAT) have been developed to diagnose H. pylori infection. Among the indirect tests, UBT and SAT became the best methods to determine active infection. While antibody-based tests, especially serology, are widely available and relatively sensitive, their specificity is low. Guidelines indicated that no single test can be considered as the gold standard for the diagnosis of H. pylori infection and that one should consider the method's advantages and disadvantages. Based on four epidemiological studies, culture and RUT present a sensitivity of 74.2-90.8% and 83.3-86.9% and a specificity of 97.7-98.8% and 95.1-97.2%, respectively, when using IHC as a gold standard. The sensitivity of serology is quite high, but that of the urine test was lower compared with that of the other methods. Thus, indirect test validation is important although some commercial kits propose universal cut-off values.
Peng, Yousong; Wang, Dayan; Wang, Jianhong; Li, Kenli; Tan, Zhongyang; Shu, Yuelong; Jiang, Taijiao
Rapid determination of the antigenicity of influenza A virus could help identify the antigenic variants in time. Currently, there is a lack of computational models for predicting antigenic variants of some common hemagglutinin (HA) subtypes of influenza A viruses. By means of sequence analysis, we demonstrate here that multiple HA subtypes of influenza A virus undergo similar mutation patterns of HA1 protein (the immunogenic part of HA). Further analysis on the antigenic variation of influenza A virus H1N1, H3N2 and H5N1 showed that the amino acid residues’ contribution to antigenic variation highly differed in these subtypes, while the regional bands, defined based on their distance to the top of HA1, played conserved roles in antigenic variation of these subtypes. Moreover, the computational models for predicting antigenic variants based on regional bands performed much better in the testing HA subtype than those did based on amino acid residues. Therefore, a universal computational model, named PREDAV-FluA, was built based on the regional bands to predict the antigenic variants for all HA subtypes of influenza A viruses. The model achieved an accuracy of 0.77 when tested with avian influenza H9N2 viruses. It may help for rapid identification of antigenic variants in influenza surveillance. PMID:28165025
Sinclair, Alison; Xie, Xuanqian; Teltscher, Marty; Dendukuri, Nandini
Standard culture methods for diagnosis of Streptococcus pneumoniae pneumonia take at least 24 h. The BinaxNOW urine-based test for S. pneumoniae (BinaxNOW-SP) takes only 15 min to conduct, potentially enabling earlier diagnosis and targeted treatment. This study was conducted to assess whether the use of BinaxNOW-SP at the time of hospital admission would provide adequate sensitivity and specificity for diagnosis of community-acquired pneumonia (CAP) in adult patients. We searched PubMed, EMBASE/OVID, Cochrane Collaboration, Centre for Reviews and Dissemination, INAHTA, and CADTH for diagnostic or etiologic studies of hospitalized predominately adult patients with clinically defined CAP that reported the diagnostic performance of BinaxNOW-SP versus cultures. Two authors independently extracted study details and diagnostic two-by-two tables. We found that 27 studies met our inclusion criteria, and three different reference standards were used between them. A bivariate meta-analysis of 12 studies using a composite of culture tests as the reference standard estimated the sensitivity of BinaxNOW-SP as 68.5% (95% credibility interval [CrI], 62.6% to 74.2%) and specificity as 84.2% (95% CrI, 77.5% to 89.3%). A meta-analysis of all 27 studies, adjusting for the imperfect and variable nature of the reference standard, gave a higher sensitivity of 74.0% (CrI, 66.6% to 82·3%) and specificity of 97.2% (CrI, 92.7% to 99.8%). The analysis showed substantial heterogeneity across studies, which did not decrease with adjustment for covariates. We concluded that the higher pooled sensitivity (compared to culture) and high specificity of BinaxNOW-SP suggest it would be a useful addition to the diagnostic workup for community-acquired pneumonia. More research is needed regarding the impact of BinaxNOW-SP on clinical practice.
Raadsma, H W; O'Meara, T J; Egerton, J R; Lehrbach, P R; Schwartzkoff, C L
The relationship between K-agglutination antibody titres and protection against experimental challenge with Dichelobacter nodosus, the effect of increasing the number of D. nodosus fimbrial antigens, and the importance of the nature of additional antigens in multivalent vaccines on antibody response and protection against experimental challenge with D. nodosus were examined in Merino sheep. A total of 204 Merino sheep were allocated to one of 12 groups, and vaccinated with preparations containing a variable number of rDNA D. nodosus fimbrial antigens. The most complex vaccine contained ten fimbrial antigens from all major D. nodosus serogroups, while the least complex contained a single fimbrial antigen. In addition to D. nodosus fimbrial antigens, other bacterial rDNA fimbrial antigens (Moraxella bovis Da12d and Escherichia coli K99), and bovine serum albumin (BSA) were used in some vaccines. Antibody titres to fimbrial antigens and BSA were measured by agglutination and ELISA tests, respectively. Antibody titres were determined on five occasions (Weeks 0, 3, 6, 8, and 11 after primary vaccination). All sheep were exposed to an experimental challenge with virulent isolates of D. nodosus from either serogroup A or B, 8 weeks after primary vaccination. For D. nodosus K-agglutinating antibody titres, a strong negative correlation between antibody titre and footrot lesion score was observed. This relationship was influenced by the virulence of the challenge strain. Increasing the number of fimbrial antigens in experimental rDNA D. nodosus fimbrial vaccines resulted in a linear decrease in K-agglutinating antibody titres to individual D. nodosus serogroups. Similarly, a linear decrease in protection to challenge with homologous serogroups was observed as the number of D. nodosus fimbrial antigens represented in the vaccine increased. The reduction in antibody titres in multicomponent vaccines is thought to be due to antigenic competition. The level of competition
Maddocks, Susan; Olma, Tom; Chen, Sharon
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
Harada, Koichi; Ohmori, Shoko; Wei, Chang-Nian; Arimatsu, Yoshiki; Ueda, Atsushi
To detect the type of contact dermatitis caused due to the handling ofAlstroemeria wilhelmina, 1% α-methylene-λ-butyrolactone (α-MBL) dissolved in physiological alien and a five-fold diluted saline solution of original extracts of flowers, leaves and stems of the flower were applied to guinea-pigs for extracts were applied to the animals as the challenge treatment in compliance with the guinea-pig maximization test (GMT). As a consequence, not only primary irritant dermatitis was observed, but also delayed type allergic contact dermatitis due toAlstroemeria wilhelmina was observed. α-MBL determined in the extracts using high-performance liquid chromatography (HPLC) was found to be the biochemical material cause of the contact dermatitis. the flower region contained α-MBL in the highest concentrations compared with those of the leaves and stems. Therefore, the quantification of α-MBL in the extracts was concluded as being a useful evaluating method for contact dermatitis due to the handling ofAlstroemeria.
Iorio, Raffaele; Lennon, Vanda A
Neural-specific autoantibodies have been documented and their diagnostic utility validated in diseases affecting the neuraxis from cerebral cortex to the somatic, autonomic, and enteric nervous system and skeletal muscle. These neurological disorders occur both idiopathically and in a paraneoplastic context. Molecular identification of the antigens has expedited development of confirmatory and high-throughput tests for serum and cerebrospinal fluid, which permit early diagnosis and reveal the underlying molecular pathogenic mechanisms. The autoantibodies are classifiable on the basis of antigen location: intracellular (nuclear or cytoplasmic) or plasma membrane. Immunohistopathological studies of patients' biopsied and autopsied tissues suggest that effector T cells mediate the autoimmune neurological disorders for which defining autoantibodies recognize intracellular antigens. Antigens within intact cells are inaccessible to circulating antibody, and the associated neurological deficits rarely improve with antibody-depleting therapies. Tumoricidal therapies may arrest neurological progression, but symptom reversal is rare. In contrast, autoantibodies specific for plasma membrane antigens have pathogenic potential, and the associated neurological deficits are often amenable to antibody-depleting immunotherapy, such as plasma exchange and anti-B-cell monoclonal antibody therapy. These reversible neurological disorders are frequently misdiagnosed as neurodegenerative. The focus of this review is the immunobiology, pathophysiology, and clinical spectrum of autoimmune neurological disorders accompanied by neural-specific IgGs.
Fairley, Derek J; McKenna, James P; Stevenson, Mike; Weaver, Jeremy; Gilliland, Carol; Watt, Alison; Coyle, Peter V
Using a Clostridium difficile glutamate dehydrogenase (GDH) immunoassay and a sensitive C. difficile toxin A/B immunoassay, human stool specimens from patients with diarrhoea (n = 1085) were classified as either GDH positive/toxin negative, or GDH positive/toxin positive. Overall, 528/725 (73%) of the GDH-positive/toxin-negative specimens contained viable C. difficile, and 433/528 (82%) of these C. difficile isolates were PCR positive for the toxin gene pathogenicity locus. Overall, 867/1078 (80%) of the GDH-positive specimens contained viable C. difficile, and 433/725 (60%) of the GDH-positive/toxin-negative specimens contained a toxigenic C. difficile strain. The diversity of toxigenic C. difficile ribotypes isolated from toxin-negative specimens (n = 433) and toxin-positive specimens (n = 339) was significantly different (P < 0.0001). Specifically, the presence of ribotype 078 strains was very strongly associated (P < 0.0001) with detection of toxin in clinical specimens using a sensitive toxin immunoassay. Specimens positive for ribotype 078 were almost twice as likely to be toxin positive as opposed to toxin negative (risk ratio = 1.90, 95% confidence interval 1.64-2.19). In contrast, other circulating ribotypes were seen with similar frequency in specimens with and without detectable toxin. This supports the view that ribotype 078 strains may be more virulent than other common ribotypes in terms of toxin production.
Dutra, Lara Ambrosio Leal; de Freitas Almeida, Gabriel Magno; Oliveira, Graziele Pereira; Abrahão, Jônatas Santos; Kroon, Erna Geessien; Trindade, Giliane de Souza
Vaccinia virus (VACV) is responsible for outbreaks in Brazil and has immense potential as an emerging virus. VACV can be found naturally circulating in India, Pakistan and South America, where it causes infections characterised by exanthematic lesions in buffaloes, cattle and humans. The transmission cycle of Brazilian VACV has still not been fully characterised; one of the most important gaps in knowledge being the role of wild animals. Capybaras, which are restricted to the Americas, are the world's largest rodents and have peculiar characteristics that make them possible candidates for being part of a natural VACV reservoir. Here, we developed a method for detecting orthopoxvirus DNA in capybara stool samples, and have described for the first time the detection of orthopoxvirus DNA in capybaras samples from three different regions in Brazil. These findings strongly suggest that capybaras might be involved in the natural transmission cycle of VACV and furthermore represent a public health problem, when associated with Brazilian bovine vaccinia outbreaks. This makes infected animals an important factor to be considered when predicting and managing Brazilian VACV outbreaks.
Kubiak, M; Kressner, B; Raynor, W; Davis, J; Syverson, R E
Single-use diapers and cloth diapers with vinyl pants were compared for their relative abilities to contain stool within the diaper. Artificial feces with carbon black as an additive allowed a quantitative measure of fecal containment by image analysis in 60 infants. This method showed complete containment of feces in the diaper in 50% of the single-use diapers whereas only 10% of the cloth diapers showed complete containment. In infants where the border of the vinyl pants was used as the boundary of containment with the cloth diapers, complete containment occurred only 33% of the time. Fluorescein dye ratings for containment/leakage in 69 infants showed that 83% of single-use diapers and 30% of the cloth diapers were rated as having no or minor leakage of feces. Cultures were taken of laundered vinyl pants that had previously been used over cloth diapers to determine microbial contamination. Thirty-nine percent of the pants contained Gram-negative, lactose-fermenting bacilli indicating fecal contamination. This study comparing single-use and cloth diapers for containment of artificial feces by use of image analysis and fluorescein dye ratings showed better containment by single-use diapers. The study also raises the question of possible spread of feces-borne pathogens by the vinyl pants used over cloth diapers, particularly in a day-care center.
Di Bonito, Paola; Della Libera, Simonetta; Petricca, Sabrina; Iaconelli, Marcello; Sanguinetti, Maurizio; Graffeo, Rosalia; Accardi, Luisa; La Rosa, Giuseppina
Human papillomaviruses (HPVs) have been detected in urban wastewaters, demonstrating that epitheliotropic viruses can find their way into sewage through the washing of skin and mucous membranes. Papillomavirus shedding through faeces is still an unexplored issue. The objective of the present study was to investigate the presence of HPVs in stool samples. We analysed 103 faecal specimens collected from hospitalized patients with diarrhoea using validated primers able to detect α, β and γ HPVs. PCR products underwent sequencing analysis and sequences were aligned to reference genomes from the Papillomavirus Episteme database. A total of 15 sequences were characterized from the faecal samples. Thirteen samples (12.6 %) were positive for nine genotypes belonging to the α and β genera: HPV32 (LR, α1), HPV39 (HR, α7), HPV44 (LR, α10), HPV8 (β1), HPV9, HPV23, HPV37, HPV38 and HPV120 (β2). Two putative novel genotypes of the β genus, species 1 and 2, were also detected. The tissue(s) of origin is unknown, since faeces can collect HPVs originating from or passing through the entire digestive system. To our knowledge, this is the first investigation on the occurrence and diversity of HPVs in faecal samples. Results from this study demonstrate that HPVs can find their way into sewage as a consequence of shedding in the faeces. This highlights the need for further studies aimed at understanding the prevalence of HPV in different water environments and the potential for waterborne transmission.
Li, Zhaoping; Henning, Susanne M; Lee, Ru-Po; Lu, Qing-Yi; Summanen, Paula H; Thames, Gail; Corbett, Karen; Downes, Julia; Tseng, Chi-Hong; Finegold, Sydney M; Heber, David
The health benefits of pomegranate (POM) consumption are attributed to ellagitannins and their metabolites, formed and absorbed in the intestine by the microbiota. In this study twenty healthy participants consumed 1000 mg of POM extract daily for four weeks. Based on urinary and fecal content of the POM metabolite urolithin A (UA), we observed three distinct groups: (1) individuals with no baseline UA presence but induction of UA formation by POM extract consumption (n = 9); (2) baseline UA formation which was enhanced by POM extract consumption (N = 5) and (3) no baseline UA production, which was not inducible (N = 6). Compared to baseline the phylum Actinobacteria was increased and Firmicutes decreased significantly in individuals forming UA (producers). Verrucomicrobia (Akkermansia muciniphila) was 33 and 47-fold higher in stool samples of UA producers compared to non-producers at baseline and after 4 weeks, respectively. In UA producers, the genera Butyrivibrio, Enterobacter, Escherichia, Lactobacillus, Prevotella, Serratia and Veillonella were increased and Collinsella decreased significantly at week 4 compared to baseline. The consumption of pomegranate resulted in the formation of its metabolites in some but not all participants. POM extract consumption may induce health benefits secondary to changes in the microbiota.
Fernández-Murga, M. Leonor; Sanz, Yolanda
Background Bacteroides uniformis CECT 7771 is a potential probiotic strain, originally isolated from the stools of healthy breast-feed infants. The strain showed pre-clinical efficacy in a mouse obesity model. The objective of this study was to evaluate its potential toxicity and translocation ability after acute oral administration to mice. Methods and Findings A safety study was conducted in immunocompetent and immunosuppressed C57BL-6 mice. Both mouse groups (n = 10 per group) were fed orally 2 x 109 colony forming units (cfu)/day of B. uniformis CECT 7771 or placebo by gavage for 6 days. Throughout this time, feed and water intake and body weight were monitored. Afterwards, mice were sacrificed and biological samples were collected to analyze blood and urine biochemistry, inflammatory and immune markers; gut mucosal histology and bacterial translocation to peripheral tissues. The results demonstrated that acute ingestion of this Bacteroides strain had no adverse effects on the animals’ general health status or food intake, nor did it affect biochemical indicators of liver, kidney and pancreatic function or gut mucosal histology. Findings also demonstrated that administration did not lead to bacterial translocation to blood, liver or mesenteric lymph nodes. B. uniformis CECT 7771 also downregulated gene and protein expression (iNOS and PPAR-γ) and inflammatory cytokines induced by immunosuppression. Conclusions The findings indicate that the acute oral consumption of B. uniformis CECT 7771 does not raise safety concerns in mice. Further studies in humans should be conducted. PMID:26784747
Obeng, B B; Aryeetey, Y A; de Dood, C J; Amoah, A S; Larbi, I A; Deelder, A M; Yazdanbakhsh, M; Hartgers, F C; Boakye, D A; Verweij, J J; van Dam, G J; van Lieshout, L
In the detection of parasitic infection, the traditional methods based on microscopy often have low sensitivity and/or specificity compared with the newer, molecular tests. An assay based on real-time PCR and a reagent strip test for detecting circulating cathodic antigen (CCA) have both now been compared with urine filtration and microscopy, in the detection of Schistosoma haematobium infections. Urine samples, obtained from 74 'cases' in areas of Ghana with endemic S. haematobium and 79 'controls' from non-endemic areas, were each checked using the three methods. With the results of the filtration and microscopy taken as the 'gold standard', real-time PCR was found to be 100% specific and 89% sensitive whereas the CCA strips were 91% specific and 41% sensitive. With the samples found to contain > or =50 eggs/10 ml (indicating relatively intense infections), the sensitivities of the PCR and CCA were higher, at 100% and 62%, respectively. As expected, egg counts were negatively correlated with the number of amplification cycles needed, in the PCR, to give a signal that exceeded the background (r=-0.38; P<0.01). Although the real-time PCR and CCA strip tests are very different, both show promise in the detection of S. haematobium infections. The PCR has optimal specificity and high sensitivity but the specificity of the CCA strips and the sensitivity of both tools could still be improved. A more thorough re-evaluation of the sensitivity and specificity of microscopy and these newer diagnostic methods, with an estimation of the cost-effectiveness of each technique, is recommended.
Four xenographic monoclonal antibodies to guinea pig Ia antigens were tested for their inhibitory effects on antigen-, alloantigen-, and mitogen-induced T cell proliferation. All four monoclonal antibodies reacted with strain 2 Ia antigens, and all four were capable of inhibiting the strain 13 against strain 2 mixed leukocyte reaction (MLR) by 50-70%; the two monoclonals that reacted with strain 13 Ia antigens were also capable of inhibiting the strain 2 against strain 13 MLR. In contrast, an analysis of the effects of a single monoclonal antibody on the responses to several antigens demonstrated a selective monoclonal pattern of inhibition in that the responses to some, but not all, antigens were inhibited. These results suggest that monoclonal antibodies react with different parts of Ia molecules that may have different functional roles and that certain parts of an Ia molecule participate in the presentation of certain antigens, whereas other regions of the same molecule present different antigens. PMID:6158543
Seyer, Ayse; Karasartova, Djursun; Ruh, Emrah; Güreser, Ayse Semra; Imir, Turgut; Taylan-Ozkan, Aysegul
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
Shehabi, A A; Masoud, H; Maslamani, F A Balkam
Pseudomonas aeruginosa was isolated in low rates from stool specimens of outpatients and inpatients (7% versus 12%) but in higher rates from chlorinated and nonchlorinated water sources (15% versus 44%), respectively in Jordan. The same biotype was recognized among 90% of P. aeruginosa isolates from patient's stools and water sources using specific biochemical profiles. Three serogroups belonging to 01, 06 and 011 accounted for the majority of these isolates in water (66%) and stools (78%), respectively. All P. aeruginosa isolates from water were highly susceptible (87%-100%) to piperacillin-tazobactam, amikacin, gentamicin, imipenem, aztreonam, ceftazidime and ciprofloxacin, whereas the isolates from stool were slightly less susceptible (81%-98%) to these antimicrobials. P. aeruginosa isolates from water and stool sources were almost equally highly resistant to tetracycline (86%-89%) and carbenicillin (88%-89%), respectively. One common small plasmid (15.4 kb) was detected in 14/25 (56%) of multidrug-resistant P. aeruginosa isolates from both water and stool. This study demonstrates certain common epidemiological characteristics including antimicrobial resistance pattern, biotypes and serotypes among P. aeruginosa isolates from patient's stools and drinking water sources in Jordan.
Ben Musa, Najla A; Ibrahim, R
A total of 949 single stool samples were collected from school aged children (5-14 years old) in the city of Tripoli. The samples were preserved in 10% formalin and examined by routine microscopy using normal saline and Lugol's iodine preparations as well as the formol ethyl concentration method after a storage period of twelve months at room temperature. Of 949 samples examined 4.5% were positive. Giardia lamblia and Entamoeba coli were the only protozoan parasites identified with an infection rate of 3.2% & 1.3% respecttively. No helminthes were detected in any of the samples. About 14% of the children had intestinal yeast infection Candida albicans in their stool of which 0.63% was infected with intestinal parasites. No distortion or alteration of morphology was observed particularly in G. lamblia. Preservation in 10% formalin is a very productive means for the accurate identification of protozoan parasites.
Hewitt, J. H.; Rigby, J.
Escherichia coli was found in a similar proportion of stool specimens from infants who were breast-fed and from others fed on three different artificial-milk preparations. When E. coli was present its mean colony count in the stools of breast-fed infants was within the range of the mean counts for infants receiving the artificial -milk feeds. There was no consistent relation between high counts of bifidobacteria (Lactobacillus bifidus) and low counts of E. coli. This suggests that measures aimed at implanting or stimulating the growth of bifidobacteria in the large intestine of artificially fed infants may not greatly influence the E. coli population therein. The results are discussed in relation to the protection of artifically fed infants from E. coli enteritis. PMID:789762
Williams, F P
Astrovirus-like, coronavirus-like, and parvovirus-like particles were detected through electron microscopic (EM) examination of loose and diarrheal stools from a litter of beagle pups. Banding patterns obtained from equilibrium centrifugations in CsCl supported the EM identification. Densities associated with the identified particles were: 1.34 g/ml for astrovirus, 1.39 g/ml for "full" parvovirus and 1.24-1.26 g/ml for "typical" coronavirus. Convalescent sera from the pups aggregated these three particle types as observed by immunoelectron microscopy (IEM). Only coronavirus-like particles were later detected in formed stools from these same pups. Coronavirus and parvo-like viruses are recognized agents of canine viral enteritis, however, astrovirus has not been previously reported in dogs.
Zeeshan, Mohammad; Zafar, Afia; Saeed, Zeb; Irfan, Seema; Sobani, Zain A; Shakoor, Sadia; Beg, Mohammad Asim
Parasitic gastrointestinal infections are a major cause of morbidity and mortality in the developing world, with stool microscopy being the mainstay of diagnostic practice. Both direct microscopy and concentration techniques can be utilized; direct microscopy may be time consuming and tedious; however clinical laboratories in developing countries lack trained staff who can effectively use concentration methods. In our practice we used the Parasep O and P filter concentrator tubes (manufactured by DiaSys Ltd, Berkshire, England. Product Code 146000) along with direct microscopic techniques and found that Parasep filters enhanced the ability to detect intestinal parasites that would have been missed on routine microscopy. We found the Parasep filter concentration method to be easy, cost-effective and reliable for routine stool examinations.
Boisen, Matt L.; Oottamasathien, Darin; Jones, Abigail B.; Millett, Molly M.; Nelson, Diana S.; Bornholdt, Zachary A.; Fusco, Marnie L.; Abelson, Dafna M.; Oda, Shun-ichiro; Hartnett, Jessica N.; Rowland, Megan M.; Heinrich, Megan L.; Akdag, Marjan; Goba, Augustine; Momoh, Mambu; Fullah, Mohammed; Baimba, Francis; Gbakie, Michael; Safa, Sadiki; Fonnie, Richard; Kanneh, Lansana; Cross, Robert W.; Geisbert, Joan B.; Geisbert, Thomas W.; Kulakosky, Peter C.; Grant, Donald S.; Shaffer, Jeffery G.; Schieffelin, John S.; Wilson, Russell B.; Saphire, Erica Ollmann; Branco, Luis M.; Garry, Robert F.; Khan, S. Humarr; Pitts, Kelly R.
Background. Throughout the 2014–2015 Ebola outbreak in West Africa, major gaps were exposed in the availability of validated rapid diagnostic platforms, protective vaccines, and effective therapeutic agents. These gaps potentiated the development of prototype rapid lateral flow immunodiagnostic (LFI) assays that are true point-of-contact platforms, for the detection of active Ebola infections in small blood samples. Methods. Recombinant Ebola and Marburg virus matrix VP40 and glycoprotein (GP) antigens were used to derive a panel of monoclonal and polyclonal antibodies. Antibodies were tested using a multivariate approach to identify antibody-antigen combinations suitable for enzyme-linked immunosorbent assay (ELISA) and LFI assay development. Results. Polyclonal antibodies generated in goats were superior reagents for capture and detection of recombinant VP40 in test sample matrices. These antibodies were optimized for use in antigen-capture ELISA and LFI assay platforms. Prototype immunoglobulin M (IgM)/immunoglobulin G (IgG) ELISAs were similarly developed that specifically detect Ebola virus–specific antibodies in the serum of experimentally infected nonhuman primates and in blood samples obtained from patients with Ebola from Sierra Leone. Conclusions. The prototype recombinant Ebola LFI assays developed in these studies have sensitivities that are useful for clinical diagnosis of acute ebolavirus infections. The antigen-capture and IgM/IgG ELISAs provide additional confirmatory assay platforms for detecting VP40 and other ebolavirus-specific immunoglobulins. PMID:26232440
Alam, Mohammad J.; Tisdel, Naradah L.; Shah, Dhara N.; Yapar, Mehmet; Lasco, Todd M.; Garey, Kevin W.
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
De Leon, R; Matsui, S M; Baric, R S; Herrmann, J E; Blacklow, N R; Greenberg, H B; Sobsey, M D
A reverse transcriptase (RT)-polymerase chain reaction (PCR)-oligoprobe (OP), or RT-PCR-OP, method was developed for the detection of the Norwalk virus, which causes acute, epidemic gastroenteritis, in stool specimens. The Norwalk virus genome regions encoding the following two proteins were amplified by RT-PCR: the RNA polymerase (260-bp product) and a putative immunogenic protein (224-bp product). The resulting DNA fragments (amplicons) were hybridized to a digoxigenin-labeled internal OP specific to each amplicon. The detection limit of Norwalk virus, as determined by the endpoint of RT-PCR amplification for serially diluted, positive stool specimens, was similar to the actual virion titer as estimated by electron microscopy and at least 100-fold greater than the titer determined by radioimmunoassay (RIA). The RT-PCR-OP assay was specific for Norwalk virus and negative for other enteric viruses, including human and animal caliciviruses, hepatitis E virus, Snow Mountain agent, astroviruses, 16 human enteroviruses, and 5 human rotaviruses. Components of fecal specimens that interfere with RT-PCR were removed successfully by Sephadex G-200 gel chromatography. Of 20 stool specimens from human volunteers that were positive for Norwalk virus by RIA, a specific RT-PCR-OP result was obtained in 95% (19 of 20) of the samples by using the immunogenic protein primers and 75% (15 of 20) by using the polymerase primers. Twenty-six stool specimens from asymptomatic children and adults were negative by the Norwalk virus RT-PCR-OP. RT-PCR-OP detected Norwalk virus in the 4 of 21 coded fecal specimens that were also positive by enzyme immunoassay. Two samples that were positive by RIA or enzyme immunoassay were negative by RT-PCR, perhaps because viral RNA was not present or RT-PCR inhibitors were not adequately removed. Images PMID:1280649
Marva, Esther; Grossman, Tamar
Microscopic examination is still considered the gold standard for the diagnosis of parasitic diseases. In many clinical laboratories in hospitals and in health maintenance organizations ("Kupot Holim"), an excellent microscopic identification of parasites is performed. Microscopic examinations using wet mount preparations are performed for the detection of protozoan trophozoites and helmintic ova or larvae. Specific concentration techniques, including flotation and sedimentation procedures are further performed for the diagnosis of parasitic diseases. However, microscopic examinations are time-consuming, non-sensitive and not always reliable. Furthermore, the diagnosis of certain infections is not always possible by searching for the parasites in host tissues or excreta since risky invasive techniques might be necessary to locate the parasites. Detection of antibodies can be very useful as an indication for infection with a specific parasite, especially in individuals with no exposure to the parasite prior to recent travel in a disease-endemic area. In addition to serology, there are other tests of high sensitivity which can be integrated with microscopy, such as antigen detection in stool and blood samples as well as the use of other molecular diagnosis methods. There are two main laboratories in Israel where parasitic diagnosis is available by integration of microscopy, serology, antigen detection and molecular methods: The Reference Laboratory for Parasitology in Jerusalem at the Central Laboratories of the Ministry of Health (MOH) and the Laboratory of Parasitology at Soroka University Medical Center, Beer Sheva (SOR). There are also two special diagnostic units, one responsible for the identification of toxopLasma: Reference Laboratory for Toxoplasmosis, Public Health Laboratory, Ministry of Health, Tel Aviv (Tox), and the other for the identification of Leishmaniasis: Kuvin Center, Faculty of Medicine, Hebrew University of Jerusalem (Kuv). This article
Hamad, Ibrahim; Sokhna, Cheikh; Raoult, Didier; Bittar, Fadi
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
Sasaki, Michihito; Orba, Yasuko; Ueno, Keisuke; Ishii, Akihiro; Moonga, Ladslav; Hang'ombe, Bernard M; Mweene, Aaron S; Ito, Kimihito; Sawa, Hirofumi
Shrews are small insectivorous mammals that are distributed worldwide. Similar to rodents, shrews live on the ground and are commonly found near human residences. In this study, we investigated the enteric virome of wild shrews in the genus Crocidura using a sequence-independent viral metagenomics approach. A large portion of the shrew enteric virome was composed of insect viruses, whilst novel viruses including cyclovirus, picornavirus and picorna-like virus were also identified. Several cycloviruses, including variants of human cycloviruses detected in cerebrospinal fluid and stools, were detected in wild shrews at a high prevalence rate. The identified picornavirus was distantly related to human parechovirus, inferring the presence of a new genus in this family. The identified picorna-like viruses were characterized as different species of calhevirus 1, which was discovered previously in human stools. Complete or nearly complete genome sequences of these novel viruses were determined in this study and then were subjected to further genetic characterization. Our study provides an initial view of the diversity and distinctiveness of the shrew enteric virome and highlights unique novel viruses related to human stool-associated viruses.
Ng, Terry Fei Fan; Zhang, Wen; Sachsenröder, Jana; Kondov, Nikola O.; da Costa, Antonio Charlys; Vega, Everardo; Holtz, Lori R.; Wu, Guang; Wang, David; Stine, Colin O.; Antonio, Martin; Mulvaney, Usha S.; Muench, Marcus O.; Deng, Xutao; Ambert-Balay, Katia; Pothier, Pierre; Vinjé, Jan; Delwart, Eric
Viral metagenomics sequencing of fecal samples from outbreaks of acute gastroenteritis from the US revealed the presence of small circular ssDNA viral genomes encoding a replication initiator protein (Rep). Viral genomes were ∼2.5 kb in length, with bi-directionally oriented Rep and capsid (Cap) encoding genes and a stem loop structure downstream of Rep. Several genomes showed evidence of recombination. By digital screening of an in-house virome database (1.04 billion reads) using BLAST, we identified closely related sequences from cases of unexplained diarrhea in France. Deep sequencing and PCR detected such genomes in 7 of 25 US (28 percent) and 14 of 21 French outbreaks (67 percent). One of eighty-five sporadic diarrhea cases in the Gambia was positive by PCR. Twenty-two complete genomes were characterized showing that viruses from patients in the same outbreaks were closely related suggesting common origins. Similar genomes were also characterized from the stools of captive chimpanzees, a gorilla, a black howler monkey, and a lemur that were more diverse than the human stool-associated genomes. The name smacovirus is proposed for this monophyletic viral clade. Possible tropism include mammalian enteric cells or ingested food components such as infected plants. No evidence of viral amplification was found in immunodeficient mice orally inoculated with smacovirus-positive stool supernatants. A role for smacoviruses in diarrhea, if any, remains to be demonstrated. PMID:27774288
Hevia, Arancha; Delgado, Susana; Margolles, Abelardo; Sánchez, Borja
The idea of considering the gut microbiota as a virtual human organ has led to the concept of fecal microbiota transplantation (FMT), which has recently been extremely successful in the treatment of cases of recurrent Clostridium difficile infection. Administration of safe, viable, and representative fecal microbiota is crucial for FMT. To our knowledge, suitable techniques and systematic conditions for separating the fecal microbiota from stool samples have not been thoroughly investigated. In this work we show the potential to separate stool microorganisms from the rest of fecal material using a procedure with a Nycodenz® density gradient, yielding 1010 viable bacteria per two grams of feces. This procedure did not affect the original microbiota composition in terms of viability, distribution and proportions, as assessed by a phylogenetic metagenomic approach. Obtaining the fecal microbiota by concentration and separation of the microorganisms from the rest of the stool components would allow the standardization of its recovery and its long-term preservation. FMT or similar microbiota restoration therapies could be used for the treatment of several disorders, or even for aesthetic purposes, so the method described in our work may contribute to the setting of the basis for the development of safe and standardized products. PMID:26581409
Kuge, T; Venkova, K; Greenwood-Van Meerveld, Beverley
Our goal was to determine whether Seirogan, an herbal medicine used as an antidiarrheal agent, modifies colonic function, including motility. Experiments were performed on four female Yucatan mini-pigs with established permanent cecal fistulas providing direct access to the colon. Long-term recordings of proximal colonic motility were accomplished by a solid-state probe (six pressure ports 10 cm apart), and a motility index was calculated. Stool viscosity was also measured. The laxative bisacodyl (15 mg/kg) was used to induce colonic motility (increase in motility index) and stool softening, prior to investigating the effect of Seirogan (2-15 mg/kg per os twice a day) or a vehicle control. Seirogan (15 mg/kg), but not the placebo, reversed the bisacodyl-induced stool softening and restored the motility index to normal values by reducing the number of propagating contractions. Taken together the results suggest that inhibition of proximal colonic motility by Seirogan may contribute to its antidiarrheal action.
Raj, G Dhinakar; Rajanathan, T M C; Kumar, C Senthil; Ramathilagam, G; Hiremath, Geetha; Shaila, M S
Peste des petits ruminants (PPR) is one of the most economically important diseases affecting sheep and goats in India. An immunofiltration-based test has been developed using either mono-specific serum/monoclonal antibodies (mAb) prepared against a recombinant truncated nucleocapsid protein of rinderpest virus (RPV) cross-reactive with PPR virus. This method consists of coating ocular swab eluate from suspected animals onto a nitrocellulose membrane housed in a plastic module, which is allowed to react with suitable dilutions of a mAb or a mono-specific polyclonal antibody. The antigen-antibody complex formed on the membrane is then detected by protein A-colloidal gold conjugate, which forms a pink colour. In the immunofiltration test, concordant results were obtained using either PPRV mAb or mono-specific serum. Another test, an antigen-competition ELISA which relies on the competition between plate-coated recombinant truncated 'N' protein of RPV and the PPRV 'N' protein present in ocular swab eluates (sample) for binding to the mono-specific antibody against N protein of RPV (in liquid phase) was developed. The cut-off value for this test was established using reverse transcription polymerase chain reaction (RT-PCR) positive and negative oculo-nasal swab samples. Linear correlation between percent inhibition (PI) values in antigen-competition ELISA and virus infectivity titres was 0.992. Comparison of the immunofiltration test with the antigen-competition ELISA yielded a sensitivity of 80% and specificity of 100%. These two tests can serve as a screening (immunofiltration) and confirmatory (antigen-competition ELISA) test, respectively, in the diagnosis of PPR in sheep or goats.
Makroo, Raj Nath; Bhatia, Aakanksha; Chowdhry, Mohit; Rosamma, N.L.; Karna, Prashant
The Miltenberger (Mi) classes represent a group of phenotypes for red cells that carry low frequency antigens associated with the MNSs blood group system. This pilot study was aimed at determining the Mia antigen positivity in the blood donor population in a tertiary care hospital in New Delhi, India. The study was performed between June to August 2014 on eligible blood donors willing to participate. Antigen typing was performed using monoclonal anti-Mia antiserum by tube technique. Only one of the 1000 blood donors (0.1%) tested was found to be Mia antigen positive. The Mia antigen can, therefore, be considered as being rare in the Indian blood donor population. PMID:27488007
Hall, James P. J.; Wang, Huanhuan; Barry, J. David
A main determinant of prolonged Trypanosoma brucei infection and transmission and success of the parasite is the interplay between host acquired immunity and antigenic variation of the parasite variant surface glycoprotein (VSG) coat. About 0.1% of trypanosome divisions produce a switch to a different VSG through differential expression of an archive of hundreds of silent VSG genes and pseudogenes, but the patterns and extent of the trypanosome diversity phenotype, particularly in chronic infection, are unclear. We applied longitudinal VSG cDNA sequencing to estimate variant richness and test whether pseudogenes contribute to antigenic variation. We show that individual growth peaks can contain at least 15 distinct variants, are estimated computationally to comprise many more, and that antigenically distinct ‘mosaic’ VSGs arise from segmental gene conversion between donor VSG genes or pseudogenes. The potential for trypanosome antigenic variation is probably much greater than VSG archive size; mosaic VSGs are core to antigenic variation and chronic infection. PMID:23853603
Neriishi, K.; Kodama, K.; Akiba, S. |
On the basis of previous studies showing an association between hepatitis B surface antigen (HBsAg) positivity and radiation exposure in atomic bomb (A-bomb) survivors, we investigated further the active state of hepatitis B virus (HBV) infection by incorporating tests of hepatitis B e antigen (HBeAg) and hepatitis B e antibody (anti-HBe) and