Comparison of parasitological, immunological and molecular methods for evaluation of fecal samples of immunosuppressed rats experimentally infected with Strongyloides venezuelensis

Parasitology ◽  
2015 ◽  
Vol 142 (14) ◽  
pp. 1715-1721 ◽  
Author(s):  
LEILANE A. CHAVES ◽  
ANA LÚCIA R. GONÇALVES ◽  
FABIANA M. PAULA ◽  
NEIDE. M. SILVA ◽  
CLÁUDIO V. SILVA ◽  
...  
Keyword(s):  
Post Infection ◽  
Pcr Amplification ◽  
Conventional Polymerase Chain Reaction ◽  
Diagnostic Value ◽  
Diagnostic Methods ◽  
Enzyme Linked Immunosorbent Assay ◽  
Fecal Samples ◽  
Infection Time ◽  
Time Points ◽  
Strongyloides Venezuelensis

SUMMARYDefinitive diagnosis of strongyloidiasis in humans is typically achieved by detection of larvae in fecal samples. However, limitations on sensitivity of parasitological methods emphasize the need for more robust diagnostic methods. The aim of this study was to compare the diagnostic value of three methods: eggs per gram of feces (EPG), coproantigen detection by enzyme linked immunosorbent assay (ELISA), and DNA detection by conventional polymerase chain reaction (PCR). The assays were performed at 0 and 5, 8, 13, 21 and 39 days post-infection (dpi) using fecal samples from experimentally infected immunocompetent and immunosuppressed rats. In immunocompetent rats, eggs were detected in feces on days 5, 8 and 13 dpi; coproantigen detection and PCR amplification were successful at all post-infection time points (5, 8, 13, 21 and 39 dpi). In immunosuppressed rats, eggs were detected at 5, 8, 13 and 21; coproantigen detection and PCR amplification were successful at all post-infection time points. In conclusion, these results suggest that coproantigen detection and PCR may be more sensitive alternatives to traditional methods such as EPG for diagnosis of Strongyloides venezuelensis infection.

scholarly journals FREQUENCY OF ENTEROPARASITOSES IN PRESCHOOL CHILDREN ATTENDING DAYCARE CENTERS: A SURVEY APPLYING PARASITOLOGICAL AND IMMUNOLOGICAL METHODS

2019 ◽  
Vol 48 (2) ◽  
pp. 121-133
Author(s):  
Gabriela Cardoso Goes ◽  
Karina Costa Coelho Gonçalves ◽  
Adriana Pittella Sudré ◽  
Danuza Pinheiro Bastos Garcia Mattos ◽  
Beatriz Brener ◽  
...  
Keyword(s):  
Optical Microscopy ◽  
Entamoeba Histolytica ◽  
Intestinal Parasites ◽  
Parasite Infection ◽  
Giardia Intestinalis ◽  
Diagnostic Methods ◽  
Immunological Methods ◽  
Enzyme Linked Immunosorbent Assay ◽  
Fecal Samples ◽  
Daycare Centers

The present study evaluated the frequency of intestinal parasitoses in children in public day care centers applying parasitological and immunological diagnostic methods. Fecal samples from 121 children from six public daycare centers were analyzed using parasitological techniques. Epidemiological data were obtained through a questionnaire, where parents and / or guardians were asked, for instance, whether the children had contact with soil, ate raw food, such as vegetables or raw or undercooked meat, normally walked around barefoot or had contact with animals. Fecal samples from 82 children were also tested for Giardia intestinalis and Cryptosporidium sp. coproantigen using the enzyme-linked immunosorbent assay (ELISA) which was also used for Entamoeba coproantigen detection only in samples that tested positive for the parasite by parasitological stool exam/optical microscopy. Intestinal parasite infection was noted in 23.1% (28/121) of the children. The most frequent parasite was Giardia intestinalis (13.2%), followed by Entamoeba coli (5.8%), Blastocystis spp. (1.7%), Endolimax nana (1.7%), Enterobius vermicularis (1.7%), Cystoisospora belli (0.8%),Entamoeba histolytica/E. dispar complex (0.8%), and Ascaris lumbricoides (0.8%). Positivity for parasite infection using parasitological stool exams was significantly associated with age groups, with a higher frequency in 4 to 6 year old children (p=0.03). No association or significant variations were noted in the prevalence of intestinal parasites in relation to the epidemiological variables studied. All samples were negative for Cryptosporidium sp. and Entamoeba histolytica detected by immunological testing, and 17.1% (14/82) children tested positive for Giardia intestinalis, although using parasitological exam/optical microscopy, only 14.6% (12/82) tested positive. The high incidence of intestinal parasites, especially protozoans, suggests probable interpersonal transmission among the children, environmental contamination, or even contaminated food/water intake. Thus, consolidation of preventive measures and efficient diagnostic resources as well as control of intestinal parasites and patient treatment are of utmost importance.

scholarly journals Diagnosis of Bubonic Plague by PCR in Madagascar under Field Conditions

2000 ◽  
Vol 38 (1) ◽  
pp. 260-263
Author(s):  
L. Rahalison ◽  
E. Vololonirina ◽  
M. Ratsitorahina ◽  
S. Chanteau
Keyword(s):  
Control Program ◽  
Diagnostic Value ◽  
Diagnostic Methods ◽  
Field Conditions ◽  
Clinical Samples ◽  
Enzyme Linked Immunosorbent Assay ◽  
Reference Laboratory ◽  
Operational Conditions ◽  
F1 Antigen ◽  
Pcr Method

ABSTRACT The diagnostic value of a PCR assay that amplifies a 501-bp fragment of the Yersinia pestis caf1 gene has been determined in a reference laboratory with 218 bubo aspirates collected from patients with clinically suspected plague managed in a regional hospital in Madagascar. The culture of Y. pestis and the detection of the F1 antigen (Ag) by enzyme-linked immunosorbent assay (ELISA) were used as reference diagnostic methods. The sensitivity of PCR was 89% (57 of 64) for the Y. pestis -positive patients, and 80.7% (63 of 78) for the F1 Ag-positive patients. The specificity of PCR for the culture-, F1 Ag-, and antibody-negative patients ( n = 105) was 100%. Because in Madagascar most patients with plague are managed and their clinical samples are collected in remote villages, the usefulness of PCR was evaluated for routine diagnostic use in the operational conditions of the control program. The sensitivity of PCR was 50% (25 of 50) relative to the results of culture and 35.2% (19 of 54) relative to the results of the F1 Ag immunocapture ELISA. The specificity of PCR under these conditions was 96%. In conclusion, the PCR method was found to be very specific but not as sensitive as culture or the F1 Ag detection method. The limitation in sensitivity may have been due to suboptimal field conditions and the small volumes of samples used for DNA extraction. This technique is not recommended as a routine diagnostic test for plague in Madagascar.

scholarly journals Seroreactivity to and Avidity for Recombinant Antigens in Toxoplasmosis

2005 ◽  
Vol 12 (8) ◽  
pp. 977-982 ◽  
Author(s):  
Klaus-Ingmar Pfrepper ◽  
Gisela Enders ◽  
Marion Gohl ◽  
Doris Krczal ◽  
Harald Hlobil ◽  
...  
Keyword(s):  
Time Course ◽  
Test System ◽  
Actual State ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibody ◽  
Recombinant Line ◽  
Past Infection ◽  
Recombinant Antigens ◽  
Infection Time ◽  
Time Points

ABSTRACT To improve serodiagnostic methods for the diagnosis of acute toxoplasmosis during pregnancy, a new test system has been developed and evaluated based on the use of recombinant antigens. Five recombinant Toxoplasma gondii antigens (ROP1, MAG1, SAG1, GRA7, and GRA8) were cloned in Escherichia coli, purified, and applied directly onto nitrocellulose membranes in a line assay (recomLine Toxoplasma). A panel of 102 sera from 25 pregnant women with supposed recent toxoplasmosis and from two symptomatic children was compared to a panel of 71 sera from individuals with past infection. Both panels were analyzed using a recombinant line assay for immunoglobulin G (IgG), IgM, and IgA antibodies and a reference enzyme-linked immunosorbent assay. Within the IgM-positive samples, antibodies against ROP1 were predominant regardless of the infection state. In IgG analysis a characteristic antibody pattern was found for very recent infections. This pattern changed to a different one during the time course of infection: antibodies against GRA7 and GRA8 were characteristic for very early IgG, whereas antibodies against SAG1 and MAG1 appeared significantly later. These results were further confirmed by determination of the IgG antibody avidity for every single recombinant antigen. In the time course of infection, IgG antibodies against the early recognized antigens matured significantly earlier than those directed against the later antigens did. The IgA patterns did not give reliable information about the infection time points. The data revealed that the recombinant line assay provides valuable information on the actual state of infection, especially during the early infection time points.

scholarly journals Progestogen metabolites for use in pregnancy monitoring of 13-lined ground squirrels (Ictidomys tridecemlineatus)

2021 ◽  
Vol 2 (2) ◽  
pp. 81-88
Author(s):  
Amy Miller ◽  
Elainna Jentz ◽  
Cassandra Duncan
Keyword(s):  
Breeding Season ◽  
Ground Squirrels ◽  
Invasive Technique ◽  
Enzyme Linked Immunosorbent Assay ◽  
Fecal Samples ◽  
Time Points ◽  
Pregnant Females ◽  
Initial Correlation ◽  
Ictidomys Tridecemlineatus ◽  
Pregnancy Status

Graphical abstract 13-lined ground squirrels (TLGS; Ictidomys tridecemlineatus) are small, omnivorous, fossorial, hibernating sciurids. TLGS are seasonal induced ovulators, with a ~28-day gestation period. The main goal of this study was to ascertain whether enzyme-linked immunosorbent assay (ELISA) of TLGS fecal samples can be used to non-invasively detect pregnancy. Competitive ELISAs for progestogen metabolites were conducted on feces collected from a group of (n =13) females. Feces were collected thrice weekly during the breeding season and frozen for subsequent analysis. Competitive ELISAs were run using progesterone kits ), setting data against seven different time-points between hibernation, emergence, and litter birthdate. Eleven females produced litters. ELISA data from the (n = 2) non-pregnant females demonstrated no rise in progestogen metabolites at any point over 28 days. In contrast, data from the (n = 11) pregnant females all demonstrated a pronounced rise in progestogen metabolites, with most animals displaying progesterone withdrawal in the final week of gestation. A >20-fold rise in progestogen metabolite was observed halfway through gestation (P < 005). Analysis on litter size and progestogen metabolite concentration showed no significant correlation (r2 = −0.615). Initial correlation analysis done on sex ratio of litters vs progestogen metabolites showed no significant effect of progesterone on sex ratios (males: r2 = −0.772, females: r2 = 0.375). This work demonstrated that TLGS also undergo progesterone withdrawal about a week before parturition. We have ascertained that a commercially available progesterone assay kit can detect a significant elevation in progestogen metabolites in this species about halfway through gestation. Lay summary This research was conducted to discover whether pregnancy prediction is possible in female 13-lined ground squirrels (TLGS; a small hibernating ground squirrel named for their number of stripes). Pregnancy status in this species, we postulated, could be anticipated by generating profiles for individuals via a non-invasive technique known as fecal endocrine hormone profiling. Fecal samples were collected from 13 females thrice weekly for 4 weeks post-hibernation in the breeding season of 2016. Fecal samples were then processed and run through an assay known as an ELISA giving concentrations of hormone metabolites excreted through feces. We then set these samples against time points to develop a profile for each female. We have ascertained that elevated progesterone (potential pregnancy) can be detected by a commercially available assay kit. Understanding hormone patterns in animals gives researchers a better idea of best husbandry practices, including breeding in managed care.

DETECTION OF ALFACORONAVIRUSES, BETACORONAVIRUSES AND ASTROVIRUSES IN BAT FECAL SAMPLES FROM MOSCOW REGION

2020 ◽  
Author(s):  
E.V. Korneenko ◽  
◽  
А.E. Samoilov ◽  
I.V. Artyushin ◽  
M.V. Safonova ◽  
...  
Keyword(s):  
High Throughput ◽  
Viral Genome ◽  
High Throughput Sequencing ◽  
Pcr Amplification ◽  
Moscow Region ◽  
Fecal Samples ◽  
Genus Level ◽  
Zoonotic Viruses ◽  
Reservoir Hosts ◽  
Blastn Search

In our study we analyzed viral RNA in bat fecal samples from Moscow region (Zvenigorod district) collected in 2015. To detect various virus families and genera in bat fecal samples we used PCR amplification of viral genome fragments, followed by high-throughput sequencing. Blastn search of unassembled reads revealed the presence of viruses from families Astroviridae, Coronaviridae and Herpesviridae. Assembly using SPAdes 3.14 yields contigs of length 460–530 b.p. which correspond to genome fragments of Coronaviridae and Astroviridae. The taxonomy of coronaviruses has been determined to the genus level. We also showed that one bat can be a reservoir of several virus genuses. Thus, the bats in the Moscow region were confirmed as reservoir hosts for potentially zoonotic viruses.

Diagnostic Value of Non-Invasive Prenatal Screening of β-thalassemia by Cell Free Fetal DNA and Fetal NRBC

2019 ◽  
Vol 19 (2) ◽  
pp. 105-111
Author(s):  
Nadia Shafei ◽  
Mohammad Saeed Hakhamaneshi ◽  
Massoud Houshmand ◽  
Siavash Gerayeshnejad ◽  
Fardin Fathi ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Multiple Displacement Amplification ◽  
Diagnostic Value ◽  
Diagnostic Methods ◽  
Beta Thalassemia ◽  
Non Invasive ◽  
Fetal Dna ◽  
Prenatal Diagnostic ◽  
Cell Free Fetal Dna ◽  
Invasive Techniques

Background: Beta thalassemia is a common disorder with autosomal recessive inheritance. The most prenatal diagnostic methods are the invasive techniques that have the risk of miscarriage. Now the non-invasive methods will be gradually alternative for these invasive techniques. Objective: The aim of this study is to evaluate and compare the diagnostic value of two non-invasive diagnostic methods for fetal thalassemia using cell free fetal DNA (cff-DNA) and nucleated RBC (NRBC) in one sampling community. Methods: 10 ml of blood was taken in two k3EDTA tube from 32 pregnant women (mean of gestational age = 11 weeks), who themselves and their husbands had minor thalassemia. One tube was used to enrich NRBC and other was used for cff-DNA extraction. NRBCs were isolated by MACS method and immunohistochemistry; the genome of stained cells was amplified by multiple displacement amplification (MDA) procedure. These products were used as template in b-globin segments PCR. cff-DNA was extracted by THP method and 300 bp areas were recovered from the agarose gel as fetus DNA. These DNA were used as template in touch down PCR to amplify b-globin gen. The amplified b-globin segments were sequenced and the results compared with CVS resul. Results: The data showed that sensitivity and specificity of thalassemia diagnosis by NRBC were 100% and 92% respectively and sensitivity and specificity of thalassemia diagnosis by cff-DNA were 100% and 84% respectively. Conclusion: These methods with high sensitivity can be used as screening test but due to their lower specificity than CVS, they cannot be used as diagnostic test.

scholarly journals Effects of management of infection source of echinococcosis in Linzhi, Tibet Autonomous Region of China

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Ying Wang ◽  
Bing-Cheng Ma ◽  
Li-Ying Wang ◽  
Gongsang Quzhen ◽  
Hua-Sheng Pang
Keyword(s):  
Infection Rate ◽  
Domestic Dog ◽  
Enzyme Linked Immunosorbent Assay ◽  
Fecal Samples ◽  
Autonomous Region ◽  
Prevention Campaign ◽  
Tibet Autonomous Region ◽  
Control And Prevention ◽  
Infection Source ◽  
Dog Infection

Abstract Background Echinococcosis is highly endemic in western and northern China. Tibet Autonomous Region (TAR) is the most serious prevalent area. Linzhi is located in southeastern part of TAR. Dogs are the primary infection source for the transmission of echinococcosis to humans. A control and prevention campaign based on dog management has been implemented in the past three years. This study aims to evaluate the effects of dog management on the infection rate of dogs. Methods Data of dog population, registration and de-worming of seven counties/district in Linzhi between 2017 and 2019 were obtained from the annual prevention and control report. Domestic dog fecal samples were collected from each endemic town of seven counties/district in Linzhi in 2019 to determine the infection of domestic dogs using coproantigen enzyme-linked immunosorbent assay (ELISA). Data analysis was processed using SPSS statistics to compare dog infection rate between 2016 and 2019 by chi-square test, and maps were mapped using ArcGIS. Results In Linzhi, domestic dog population has decreased from 17 407 in 2017 to 12 663 in 2019, while the registration rate has increased from 75.9% in 2017 to 98.6% in 2019. Similarly, stray dog population has decreased from 14 336 in 2017 to 11 837 in 2019, while sheltered rate has increased from 84.6% in 2017 to 96.6% in 2019. Dog de-worming frequency has increased from 4 times per annum in 2017 to 12 times in 2019, indicating that approximately every dog was dewormed monthly. A total of 2715 dog fecal samples were collected for coproantigen ELISA assay. The dog infection rate was 2.8% (77/2715) in 2019, which was significantly lower than 7.3% (45/618) in 2016 (P < 0.05). Conclusions Increased dog registration, decreased dog population, and increased dog de-worming frequency contributed to significantly decrease the dog infection rate in Linzhi. Control and prevention campaign based on dog management could significantly decrease dog infection with Echinococcus spp. in echinococcosis endemic areas.

scholarly journals SARS-CoV-2 IgG Antibodies Seroprevalence and Sera Neutralizing Activity in MEXICO: A National Cross-Sectional Study during 2020

2021 ◽  
Vol 9 (4) ◽  
pp. 850
Author(s):  
José Esteban Muñoz-Medina ◽  
Concepción Grajales-Muñiz ◽  
Angel Gustavo Salas-Lais ◽  
Larissa Fernandes-Matano ◽  
Constantino López-Macías ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Neutralizing Antibodies ◽  
Herd Immunity ◽  
Cross Sectional Study ◽  
Molecular Techniques ◽  
Diagnostic Methods ◽  
Molecular Diagnostic ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cross Sectional ◽  
Neutralizing Activity

Until recently, the incidence of COVID-19 was primarily estimated using molecular diagnostic methods. However, the number of cases is vastly underreported using these methods. Seroprevalence studies estimate cumulative infection incidences and allow monitoring of transmission dynamics, and the presence of neutralizing antibodies in the population. In February 2020, the Mexican Social Security Institute began conducting anonymous unrelated sampling of residual sera from specimens across the country, excluding patients with fever within the previous two weeks and/or patients with an acute respiratory infection. Sampling was carried out weekly and began 17 days before Mexico’s first officially confirmed case. The 24,273 sera obtained were analyzed by chemiluminescent-linked immunosorbent assay (CLIA) IgG S1/S2 and, later, positive cases using this technique were also analyzed to determine the rate of neutralization using the enzyme-linked immunosorbent assay (ELISA). We identified 40 CLIA IgG positive cases before the first official report of SARS-CoV-2 infection in Mexico. The national seroprevalence was 3.5% in February and 33.5% in December. Neutralizing activity among IgG positives patients during overall study period was 86.1%. The extent of the SARS-CoV-2 infection in Mexico is 21 times higher than that reported by molecular techniques. Although the general population is still far from achieving herd immunity, epidemiological indicators should be re-estimated based on serological studies of this type.

Urine β-2-glycoprotein 1 as a biomarker for diagnosis of systemic lupus erythematosus

Lupus ◽  
2021 ◽  
pp. 096120332110142
Author(s):  
Jung Sun Lee ◽  
Eun-Ju Lee ◽  
Jeonghun Yeom ◽  
Ji Seon Oh ◽  
Seokchan Hong ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Lupus Erythematosus ◽  
Medical Center ◽  
Characteristic Curve ◽  
Area Under The Curve ◽  
Diagnostic Value ◽  
Urine Samples ◽  
Enzyme Linked Immunosorbent Assay ◽  
Systemic Lupus ◽  
Asan Medical

Objective The need for a biomarker with robust sensitivity and specificity in diagnosing systemic lupus erythematosus (SLE) remains unmet. Compared with blood samples, urine samples are more easily collected; thus, we aimed to identify such a biomarker based on urinary proteomics which could distinguish patients with SLE from healthy controls (HCs). Methods Urine samples were collected from 76 SLE patients who visited rheumatology clinic in 2019 at Asan medical center and from 25 HCs. Urine proteins were analyzed using sequential windowed acquisition of all theoretical fragment ion spectra-mass spectrometry, and the candidate marker was confirmed by enzyme-linked immunosorbent assay (ELISA). Receiver operating characteristic curve analysis was used to determine the diagnostic value of the candidate biomarker. Results Of 1157 proteins quantified, 153 were differentially expressed in urine samples from HCs. Among them were previously known markers including α-1-acid glycoprotein 1, α-2-HS-glycoprotein, ceruloplasmin, and prostaglandin-H2 D-isomerase. Moreover, the amount of β-2 glycoprotein (APOH) was increased in the urine of patients with SLE. The ELISA results also showed the level of urine APOH was higher in patients with SLE than in HCs and patients with rheumatoid arthritis. Moreover, the level was not different between SLE patients with and without nephritis. The urine APOH had an area under the curve value of 0.946 at a cut-off value of 228.53 ng/mg (sensitivity 91.5%, specificity 92.0%) for the diagnosis of SLE. Conclusion The results indicate that the urine APOH level can be an appropriate screening tool in a clinical setting when SLE is suspected.

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