scholarly journals Porcine reproductive and respiratory syndrome virus (PRRSV) antibody levels in large swine farms in selected regions of Yunnan province, China

2021 ◽  
Vol 77 (10) ◽  
pp. 6581-2021
Author(s):  
DIANGANG HAN ◽  
HONGQING YANG ◽  
YUNQING YANG ◽  
LINGLING YE ◽  
JUN DONG ◽  
...  
Keyword(s):  
Disease Surveillance ◽  
Large Scale ◽  
Yunnan Province ◽  
Age Groups ◽  
Respiratory Syndrome Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Prrs Virus ◽  
Swine Farms ◽  
Antibody Levels

Porcine reproductive and respiratory syndrome (PRRS) is caused by the PRRS virus (PRRSV), and it is a widespread disease that severely affects swine production in all age groups. Detection of PRRSV antibody levels in pig farms is beneficial for immunity evaluations. In this study, a total of 1,206 serum samples of breeding boars, breeding sows, reserve pigs and commercial pigs from 16 large-scale swine farms in 4 different regions of Yunnan province in China were collected during 2019 and detected by indirect enzyme-linked immunosorbent assay (ELISA). The results showed that the average positive rate of PRRSV antibody was 88.32%, among which the antibody-positive rates were 89.03%, 89.18%, 92.11%, and 82.95% in East Yunnan (E. Yunnan), Central Yunnan (Cent. Yunnan), Northwest Yunnan (N.W. Yunnan) and Northeast Yunnan (N.E. Yunnan), respectively (P > 0.05). For the different pig categories, the reserve pigs (93.51%) showed much higher antibody-positive rates, followed by breeding sows (92.44%), commercial pigs (87.34%) and breeding boars (85.62%). Statistical analysis revealed that the rates were significantly different among different pig categories (P <0.05). These s results indicated that pig categories were significantly associated with PRRSV antibody levels in this study. All the positive rates in this study fulfilled the requirement of ≥ 70% set by the National Animal Disease Surveillance Plan of China (2011). The study could provide evidence of the antibody response of PRRSV at the farm level.

scholarly journals Serological Evaluation of Specific-Antibody Levels in Patients Treated for Chronic Chagas' Disease

2007 ◽  
Vol 15 (2) ◽  
pp. 297-302 ◽  
Author(s):  
Olga Sánchez Negrette ◽  
Fernando J. Sánchez Valdéz ◽  
Carlos D. Lacunza ◽  
María Fernanda García Bustos ◽  
María Celia Mora ◽  
...  
Keyword(s):  
Chagas Disease ◽  
Treatment Effectiveness ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Serological Tests ◽  
Recombinant Antigens ◽  
Antibody Titers ◽  
Laboratory Procedures ◽  
The Individual ◽  
Antibody Levels

ABSTRACT Serological tests are the main laboratory procedures used for diagnosis during the indeterminate and chronic stages of Chagas' disease. A serological regression to negativity is the main criterion used to define parasitological cure in treated patients. The aim of this work was to monitor the individual specificities of antibody levels for 3 years posttreatment in 18 adult patients. Conventional serological techniques (hemagglutination assays and enzyme-linked immunosorbent assay [ELISA]) were modified by using recombinant antigens to detect early markers of treatment effectiveness. For this purpose, serum samples were taken before and during treatment and every 6 months after treatment for at least 3 years. When hemagglutination assays were used, a decrease in antibody levels was observed in only one patient. When ELISA with serum dilutions was used, antibody clearance became much more apparent: in 77.7% (14/18) of the patients, antibody titers became negative with time. This was observed at serum dilutions of 1/320 and occurred between the 6th and the 30th months posttreatment. The immune response and the interval for a serological regression to negativity were different for each patient. For some of the recombinant antigens, only 50% (9/18) of the patients reached the serological regression to negativity. Recombinant antigen 13 might be a good marker of treatment effectiveness, since 66.6% (six of nine) of the patients presented with an early regression to negativity for specific antibodies to this antigen (P = 0.002).

Comparison of an enzyme-linked immunosorbent assay for quantitation of rotavirus antibodies with complement fixation in an epidemiological survey

1978 ◽  
Vol 8 (3) ◽  
pp. 268-276
Author(s):  
L H Ghose ◽  
R D Schnagl ◽  
I H Holmes
Keyword(s):  
Immunosorbent Assay ◽  
Complement Fixation ◽  
Age Groups ◽  
Enzyme Reaction ◽  
Epidemiological Survey ◽  
Enzyme Linked Immunosorbent Assay ◽  
Marker Enzyme ◽  
Aminosalicylic Acid ◽  
Antibody Titers ◽  
Antibody Levels

The development of a micro-scale enzyme-linked immunosorbent assay (ELISA) with horseradish peroxidase as the marker enzyme for the detection and measurement of human rotavirus antibodies is described. A semipurified preparation of the serologically related simian agent, SA-11 virus, was used as the antigen. Test sera were reacted with antigen-sensitized wells in disposable poly-vinyl microplates. Any attached antibody was detected by the addition of peroxidase-labeled anti-species immunoglobulin (conjugate) followed by assay of the enzyme reaction with its substrate, hydrogen peroxide plus 5-aminosalicylic acid. This micro-ELISA was compared with complement fixation in a seroepidemiological study of the age prevalence of rotavirus antibody in Aboriginal and European populations living in the same outback area in Australia. The ELISA (results read with the naked eye) proved to be approximately 16 times more sensitive than complement fixation. Of Aborigines, 71% had rotavirus complement-fixing antibody, as compared to 45% of Europeans. By ELISA 100% of both populations had rotavirus antibodies. Mean antibody titers in the different age groups were higher in Aborigines than in Europeans. Antibody levels rose steeply throughout the first 20 years of life, remained high during the next 20 years, then increased again at least up to the age of 60 years. The micro-ELISA was practical, simple to perform, and more suitable than complement fixation for large seroepidemiological rotavirus studies. It also has potential for serodiagnosis of the disease, both in the laboratory and in the field.

scholarly journals Specificity and Prevalence of Natural Bovine Antimannan Antibodies

1999 ◽  
Vol 6 (6) ◽  
pp. 946-952 ◽  
Author(s):  
Abhay Srinivasan ◽  
Yawei Ni ◽  
Ian Tizard
Keyword(s):  
Age Groups ◽  
Inhibitory Effect ◽  
Enzyme Linked Immunosorbent Assay ◽  
Dependent Manner ◽  
Serum Samples ◽  
Adult Cattle ◽  
Calcium Dependent ◽  
High Concentrations ◽  
Carbohydrate Components ◽  
A Minor

ABSTRACT Immune responses to the carbohydrate components of microorganisms, mediated both by antibodies and by lectins, are an important part of host defense. In the present experiments, the specificity and presence of natural bovine antibodies against mannan, a common fungal antigen, were examined by enzyme-linked immunosorbent assay (ELISA), usingSaccharomyces cerevisiae mannan as an antigen. The results showed that all serum samples from animals of three age groups (newborn, calf, and adult) tested contained antimannan antibodies, and the titer of these antibodies increased significantly in adults. However, titers among individual adult cattle differed widely. Inhibition assays showed that yeast mannan was the strongest inhibitor.d-Mannose exhibited only a minor inhibitory effect at high concentrations. This suggests that most of these antibodies recognize an oligosaccharide-based epitope(s) different from those recognized by lectins. Cattle possess three serum C-type lectins (collectins) capable of recognizing mannan in a calcium-dependent manner. Addition of EDTA to the reaction did not reduce antibody binding, suggesting that the binding of these antibodies to mannan was not affected by the presence of collectin. The antibodies purified from either calf or adult serum by mannan-Sepharose affinity chromatography consisted of mainly immunoglobulin G (IgG) and a smaller amount of IgM. IgG1 was shown to be the dominant antimannan IgG isotype by isotype-specific ELISA. Together, these results demonstrate the production of natural antimannan antibodies in cattle in an age-dependent manner. These antibodies might be involved in defending the host against mannan-containing pathogens as a specific line of defense in conjunction with the innate response by lectins.

scholarly journals Detection of avian reovirus antibodies in layer birds of small scale commercial farms in Dinajpur district of Bangladesh

2016 ◽  
Vol 1 (3) ◽  
pp. 612-621 ◽  
Author(s):  
Abdus Salam ◽  
Md Atiqul Haque ◽  
Md Mostafizer Rahman ◽  
Mir Rowshan Akter ◽  
Farzana Afroz
Keyword(s):  
Antibody Titer ◽  
Specific Antibody ◽  
Age Groups ◽  
Antibody Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Small Scale ◽  
Avian Reovirus ◽  
Serum Samples ◽  
Aged Group ◽  
Test Kit

The present study was conducted on layer birds of different age groups to determine specific antibody titer level against avian reovirus (ARV) by indirect enzyme linked immunosorbent assay (iELISA) at Dinajpur district of Bangladesh. This study showed that ARV specific antibody positive cases were 84 out of 90 blood serum samples and the highest antibody titer was 26120 and lowest antibody titer was 288. The total 93.33% sera samples were showed positive result. The study showed that 100% sera sample were positive against ARV at 6 weeks of aged group and the highest, lowest and mean antibody titer were 13917, 4895 and 10269 respectively. On the other hand 88.88% sera sample were positive against ARV at 10 weeks of aged group and the highest, lowest and mean antibody titer were 9779, 288 and 5689.89 respectively. The sera sample collected from 14 weeks of aged group showed 88.88% positive and the highest, lowest and mean antibody titer were 11727, 871 and 5250 respectively. The sera sample collected from 18 weeks of aged group showed 88.88% positive against ARV and the highest, lowest and mean antibody titer were 24440, 1234 and 12648.89 respectively. The sera sample collected from 22 weeks of aged group were 100% positive against ARV and the highest, lowest and mean antibody titer were 26120, 1752 and 11373.89 respectively. The sera sample collected from 26 weeks of aged group showed 100% positive against ARV and the highest, lowest and mean antibody titer were 8566, 1630 and 4327.44 respectively. The sera sample collected from 30 weeks of aged group showed 100% positive against ARV and the highest, lowest and mean antibody titer were 13431, 1989 and 5890.56 respectively. The sera sample collected from 40 weeks of aged group showed 77.77% positive against ARV and the highest, lowest and mean antibody titer were 14618, 433 and 5103.22 respectively. The sera sample collected from 48 weeks of aged group showed 88.88% positive against ARV and the highest, lowest and mean antibody titer were 14553, 957 and 7436.5 respectively. In conclusion it is evident that avian reovirus-specific antibody was successfully detected through commercially available avian reovirus antibody test kit (ELISA kit) and the virus induced a significant antibody titer indicating the affecting virus was absolutely ARV.Asian J. Med. Biol. Res. December 2015, 1(3): 612-621

scholarly journals Expression of the Campylobacter jejuni FliD protein and its reaction to chicken sera

2020 ◽  
Vol 367 (14) ◽  
Author(s):  
Xiao-Yan Zhang ◽  
Qian Zhou ◽  
Meng-Jun Tang ◽  
Jun-Hua Pu ◽  
Yan-Feng Fan ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Broiler Chickens ◽  
Human Infection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Capping Protein ◽  
Cultural Status ◽  
Bacterial Gastroenteritis ◽  
Antibody Levels ◽  
Culture Negative

ABSTRACT Campylobacter is a leading causative pathogen of acute bacterial gastroenteritis among humans. Contaminated chicken products are regarded as major sources of human infection. The flagellar capping protein (FliD), which plays important roles in colonization and adhesion to the mucosal surface of chicken ceca, is conserved among Campylobacter jejuni strains. In this study, the recombinant C. jejuni FliD protein was expressed, purified and used as a coated protein to examine the prevalence of C. jejuni antibodies in chickens. The anti-FliD antibody was prevalent among chicken serum samples taken from different farms in the diverse regions of Jiangsu province by using enzyme-linked immunosorbent assay. The Campylobacter antibody was present in culture-negative chickens. No strong dose–response relationships were observed between serum FliD antibody levels and Campylobacter cultural status. These results provide a basis for further evaluating FliD as a vaccine candidate for broiler chickens or for examining host–C. jejuni interactions, with implications for improving food safety.

scholarly journals IgM and IgA Antibody Responses in 12 Cases of Human Acquired Toxoplasmosis

1997 ◽  
Vol 39 (6) ◽  
pp. 327-332 ◽  
Author(s):  
Emília E. H. TAKAHASHI ◽  
Cláudio L. ROSSI
Keyword(s):  
Serological Test ◽  
Clinical Manifestations ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Igm Antibodies ◽  
Iga Antibodies ◽  
Direct Elisa ◽  
Acute Toxoplasmosis ◽  
Antibody Levels ◽  
Acquired Toxoplasmosis

The persistence, in some subjects, of specific IgM antibodies to Toxoplasma gondii for several months after the acute phase of infection has complicated the interpretation of serological test results for toxoplasmosis. Several reports have emphasized the value of the detection of Toxoplasma-specific IgA antibodies for the diagnosis of acute toxoplasmosis. In this article, we report the follow-up profiles of Toxoplasma-specific IgM and IgA antibodies in serum samples obtained from 12 patients at various intervals after the onset of the clinical manifestations of infection. IgM antibodies were detected by the indirect immunofluorescence (IIF) test, antibody capture enzyme-linked immunosorbent assay (cELISA) and enzyme-mediated chemilluminescent technique (CmL). IgA antibodies were quantified by the direct ELISA (dELISA) and cELISA procedures. As defined by the manufacturer of the cELISA test for IgA used, most patients with acute toxoplasmosis have antibody levels > 40 arbritary units per ml (AU/ml). At values > 40 AU/ml, the cELISA for IgA detected significant antibody levels for a shorter time than the other techniques used for IgM and IgA detection. However, IgA levels <FONT FACE="Symbol">£</font> 40 AU/ml do not exclude the possibility of acute toxoplasmosis since such levels can be reached very soon after infection with T. gondii. The results obtained in the present study show that the serological diagnosis of acute toxoplasmosis may not be such an easy task. Our data suggest that use of the IgA-cELISA concomitantly with IgM antibody screening could permit, in some circumstances, a more efficient diagnosis of acute acquired toxoplasmosis

scholarly journals Tetanus Immunity among Women Aged 15 to 39 Years in Cambodia: a National Population-Based Serosurvey, 2012

2016 ◽  
Vol 23 (7) ◽  
pp. 546-554 ◽  
Author(s):  
Heather M. Scobie ◽  
Bunsoth Mao ◽  
Sokhal Buth ◽  
Kathleen A. Wannemuehler ◽  
Charlotte Sørensen ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Population Based ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cluster Sampling ◽  
Serum Samples ◽  
Nulliparous Women ◽  
Vaccination Campaigns ◽  
Antibody Levels ◽  
Multiple Pathogens ◽  
Tetanus Immunity

To monitor progress toward maternal and neonatal tetanus elimination (MNTE) in Cambodia, we conducted a nationwide serosurvey of tetanus immunity in 2012. Multistage cluster sampling was used to select 2,154 women aged 15 to 39 years. Tetanus toxoid antibodies in serum samples were measured by gold-standard double-antigen enzyme-linked immunosorbent assay (DAE) and a novel multiplex bead assay (MBA). Antibody concentrations of ≥0.01 IU/ml by DAE or the equivalent for MBA were considered seroprotective. Estimated tetanus seroprotection was 88% (95% confidence interval [CI], 86 to 89%); 64% (95% CI, 61 to 67%) of women had antibody levels of ≥1.0 IU/ml. Seroprotection was significantly lower (P< 0.001) among women aged 15 to 19 years (63%) and 20 to 24 years (87%) than among those aged ≥25 years (96%), among nulliparous women than among parous women (71 versus 97%), and among those living in the western region than among those living in other regions (82 versus 89%). The MBA showed high sensitivity (99% [95% CI, 98 to 99%]) and specificity (92% [95% CI, 88 to 95%]) compared with DAE. Findings were compatible with MNTE in Cambodia (≥80% protection). Tetanus immunity gaps should be addressed through strengthened routine immunization and targeted vaccination campaigns. Incorporating tetanus testing in national serosurveys using MBAs, which can measure immunity to multiple pathogens simultaneously, may be beneficial for monitoring MNTE.

scholarly journals Evaluation of Inapparent Nosocomial Severe Acute Respiratory Syndrome Coronavirus Infection in Vietnam by Use of Highly Specific Recombinant Truncated Nucleocapsid Protein-Based Enzyme-Linked Immunosorbent Assay

2005 ◽  
Vol 12 (7) ◽  
pp. 848-854 ◽  
Author(s):  
Fuxun Yu ◽  
Mai Quynh Le ◽  
Shingo Inoue ◽  
Hong Thi Cam Thai ◽  
Futoshi Hasebe ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Large Scale ◽  
Screening Method ◽  
Epidemiological Studies ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Nucleocapsid Proteins ◽  
N Protein ◽  
Care Workers ◽  
Coronavirus Infection

ABSTRACT Severe acute respiratory syndrome (SARS) is a recently emerged human disease associated with pneumonia. Inapparent infection with SARS coronavirus (CoV) is not well characterized. To develop a safe, simple, and reliable screening method for SARS diagnosis and epidemiological study, two recombinant SARS-CoV nucleocapsid proteins (N′ protein and NΔ121 protein) were expressed in Escherichia coli, purified by affinity chromatography, and used as antigens for indirect, immunoglobulin G enzyme-linked immunosorbent assays (ELISA). Serum samples collected from healthy volunteers and SARS patients in Vietnam were used to evaluate the newly developed methods. The N′ protein-based ELISA showed a highly nonspecific reaction. The NΔ121 protein-based ELISA, with a nonspecific reaction drastically reduced compared to that of the nearly-whole-length N′ protein-based ELISA, resulted in higher rates of positive reactions, higher titers, and earlier detection than the SARS-CoV-infected cell lysate-based ELISA. These results indicate that our newly developed SARS-CoV NΔ121 protein-based ELISA is not only safe but also a more specific and more sensitive method to diagnose SARS-CoV infection and hence a useful tool for large-scale epidemiological studies. To identify inapparent SARS-CoV infections, serum samples collected from health care workers (HCWs) in Vietnam were screened by the NΔ121 protein-based ELISA, and positive samples were confirmed by a virus neutralization test. Four out of 149 HCWs were identified to have inapparent SARS-CoV infection in Vietnam, indicating that subclinical SARS-CoV infection in Vietnam is rare but does exist.

scholarly journals Immunoglobulin G, A and M Light Chain Ratio in Children

1992 ◽  
Vol 29 (3) ◽  
pp. 271-274 ◽  
Author(s):  
Á Haraldsson ◽  
C M R Weemaes ◽  
M J H Kock-Jansen ◽  
P B J M v Eck-Arts ◽  
T de Boo ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Light Chain ◽  
Immunoglobulin G ◽  
Age Groups ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Λ Light Chain

Values for the κ/λ light chain ratio in immunoglobulins G, A and M and the total κ/λ ratio, measured by enzyme linked immunosorbent assay, were evaluated in serum samples from different age groups (114 children, aged from 1 month to 15 years, and 20 adults). The IgG κ/λ ratio decreased in the first 6 months and subsequently increased slowly during childhood towards the adult value of 2·0. The IgM κ/λ ratio increased at a greater rate than IgG κ/λ ratio in the first years of life and thereafter rose slightly throughout childhood to reach an adult value of 1·7. A decreasing IgA κ/λ ratio was found from 1 month of age onwards to an adult value of 1·1. The pattern of total κ/λ ratio was similar to the IgG κ/λ ratio with an adult value of 2·0.

The effect of plasma exchange on serum anti-JC virus antibodies

2012 ◽  
Vol 19 (7) ◽  
pp. 912-919 ◽  
Author(s):  
Meena Subramanyam ◽  
Tatiana Plavina ◽  
Bhupendra O Khatri ◽  
Robert J Fox ◽  
Susan E Goelz
Keyword(s):  
Plasma Exchange ◽  
Immune Reconstitution ◽  
Jc Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Fold Reduction ◽  
The Central Nervous System ◽  
Igg Isotypes ◽  
Circulating Antibodies ◽  
Antibody Levels

Objective: Natalizumab, a highly effective treatment for multiple sclerosis (MS) and Crohn’s disease, is associated with progressive multifocal leukoencephalopathy (PML). Upon suspicion or diagnosis of PML, plasma exchange (PLEX) is performed to remove natalizumab from the circulation, allowing immune reconstitution of the central nervous system. Since PLEX may also remove other circulating antibodies, we examined the effects of PLEX on serum immunoglobulin (IgG) and anti–JC virus (JCV) antibody levels in MS patients with and without PML. Methods: Serum samples from 12 natalizumab-treated patients without PML collected before, during and after PLEX were tested for IgG isotypes using a commercial assay, and for anti-JCV antibodies using a two-step enzyme-linked immunosorbent assay. Five natalizumab-treated PML patients who underwent PLEX were also tested for anti-JCV antibodies. Results: PLEX produced a two- to three-fold reduction in all IgG isotypes. Among patients without PML, 42% (five of 12 patients) had detectable anti-JCV antibodies before PLEX; in these patients, anti-JCV antibodies were reduced approximately two- to five-fold, with levels returning to 50–100 percent of baseline two weeks after the final PLEX. The five PML patients, all of whom had detectable anti-JCV antibodies before PLEX, experienced similar reductions in anti-JCV antibody levels following PLEX. Conclusions: Our results indicate that PLEX effectively removes circulating antibodies; however, levels of endogenous anti-JCV antibody, unlike exogenously administered natalizumab, were replenished relatively quickly following PLEX. While interpretation of anti-JCV antibody levels during or within two weeks after PLEX may be problematic, humoral JCV immunity is not abolished by PLEX and antibody levels are rapidly restored.

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