Comparative study of assays detecting circulating immune complexes and specific antibodies in patients infected with Toxocara canis

1987 ◽  
Vol 61 (3) ◽  
pp. 196-202 ◽  
Author(s):  
C. Aguila ◽  
C. Cuéllar ◽  
S. Fenoy ◽  
J. L. Guillén
Keyword(s):  
Monoclonal Antibodies ◽  
Comparative Study ◽  
Immune Complexes ◽  
Sandwich Elisa ◽  
Toxocara Canis ◽  
Circulating Immune Complexes ◽  
Soluble Antigen ◽  
Elisa Method ◽  
Active Infection ◽  
Specific Antibodies

ABSTRACTA sandwich ELISA method using previously described E/S antigen-specific monoclonal antibodies has been developed to detect circulating immune complexes in patients infected with Toxocara canis. This technique could be used for the study of the dynamics of the parasite-host relationship, as we believe the detection of immune complexes and/or soluble antigen to be an improvement over detection of antibodies only. In this parasitosis, antibodies may be present in residual levels for prolonged periods after active infection.

Monoclonal antibodies multireactive with parasite antigens produced by hybridomas generated from naive mice

Parasitology ◽  
1997 ◽  
Vol 115 (4) ◽  
pp. 387-393 ◽  
Author(s):  
E. KONISHI
Keyword(s):  
Monoclonal Antibodies ◽  
Fasciola Hepatica ◽  
Toxocara Canis ◽  
Plasmodium Yoelii ◽  
Natural Antibodies ◽  
Enzyme Linked Immunosorbent Assay ◽  
Soluble Antigen ◽  
Lethal Challenge ◽  
Multiple Antigen

Hybridoma clones producing IgM naturally occurring (natural) antibodies were generated from naive Balb/c mice and characterized for reactivity against parasite antigens. Ascites of mice injected with these hybridomas reacted with Toxoplasma gondii soluble antigen at levels approximately 1000–10000 times higher than serum pooled from mice used for generating hybridomas as determined by a conventional enzyme-linked immunosorbent assay. Western blot analysis indicated that these monoclonal antibodies reacted with multiple antigen molecules of T. gondii with patterns similar to that of pooled mouse sera. These antibodies also reacted with multiple antigens of Plasmodium yoelii, Entamoeba histolytica, Ascaris lumbricoides, Toxocara canis, Trichuris vulpis, Fasciola hepatica, Schistosoma mansoni, and Dipylidium caninum. When one monoclonal antibody was absorbed with these parasite antigens, its reactivity with T. gondii antigen molecules was consistently reduced, independent of parasite species. These natural antibodies failed to kill T. gondii tachyzoites in vitro or to protect mice from lethal challenge with T. gondii. These results indicate that natural antibodies detected in sera of naive mice are secreted from certain B cell populations and that these antibodies are multireactive with parasite antigens and have low affinity.

Rapid Detection of Salmonella spp. in Foods by Combination of a New Selective Enrichment and a Sandwich ELISA Using Two Monoclonal Antibodies against Dulcitol 1-Phosphate Dehydrogenase

1996 ◽  
Vol 59 (11) ◽  
pp. 1158-1163 ◽  
Author(s):  
HUAIZE TIAN ◽  
TAKAHISA MIYAMOTO ◽  
TAKASHI OKABE ◽  
YOICHIRO KURAMITSU ◽  
KEN-ICHI HONJOH ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Rapid Detection ◽  
Enrichment Culture ◽  
Sandwich Elisa ◽  
False Negative ◽  
Detection Sensitivity ◽  
Elisa Method ◽  
Salmonella Spp ◽  
Selective Enrichment ◽  
Raw Foods

A rapid-detection method was developed for food-borne dulcitol-positive Salmonella spp. in foods that involves a new preenrichment and selective enrichment system and a sandwich ELISA using two monoclonal antibodies against dulcitol 1-phosphate dehydrogenase. Preenrichment and selective enrichment were in Enterobacteriaceae enrichment mannitol (EEM) broth at 42°C for 6 h and in a new dulcitol-magnesium chloride-pyridinesulfonic acid brilliant green-novobiocin (DMPBN) medium at 42°C for 27 h, respectively. The cells were collected from the selective enrichment culture and suspended in 0.1 ml of 1 N NaOH for 2 min. The solution was neutralized with 0.1 ml of 2 M Tris-HCl buffer (pH 7.5) and the mixture was used as a sample for ELISA. The detection sensitivity of the ELISA was 105 CFU of Salmonella spp. per ml of culture. Competing non-Salmonella organisms in raw food did not interfere with the detection of Salmonella cells even when present at 107: 1 (non-Salmonella: Salmonella ratio) in food. Nonmotile Salmonella gallinarum was detected by the ELISA. The minimum detectable number of initial inoculum of Salmonella typhimurium was 0.69 CFU/25 g of raw chicken after the preenrichment in EEM broth and the selective enrichment in DMPBN medium. The present ELISA method required a total analysis time of 36 h including the preenrichment and selective enrichment periods. The ELISA method was compared with a conventional cultural method for the detection of Salmonella cells in 130 samples of raw foods. Of the samples tested, 16 were Salmonella-positive and 114 samples were negative by both methods. False-positive and false-negative results were not encountered.

scholarly journals Detection of Toxoplasma gondii soluble antigen, SAG-1(p30), antibody and immune complex in the cerebrospinal fluid of HIV positive or negative individuals

1999 ◽  
Vol 41 (6) ◽  
pp. 329-338 ◽  
Author(s):  
Flávia A. CHAVES-BORGES ◽  
Maria A. SOUZA ◽  
Deise A. O. SILVA ◽  
Lloyd H. KASPER ◽  
José R. MINEO
Keyword(s):  
Cerebrospinal Fluid ◽  
Immune Complexes ◽  
Clinical Findings ◽  
Toxoplasmic Encephalitis ◽  
Hiv Positive ◽  
Soluble Antigen ◽  
Active Infection ◽  
Toxoplasma Infection ◽  
Specific Igg ◽  
Major Surface

Active infection by T. gondii was evaluated by immunoassay for soluble SAG-1 (p30), the major surface antigen from T. gondii, specific antibodies and immune complexes in human cerebrospinal fluid (CSF) samples. A total of 263 samples of CSF were collected from hospitalized patients presenting neurological disorders and analyzed for antibodies to HIV. Patients were divided into two groups: HIV positive (n = 96) or HIV negative (n =167). The results of the assays showed that 45% of all samples were positive for soluble SAG-1. Toxoplasma Ag/Ab immune complexes were detected in 19% of the CSF samples and 62% were positive for T. gondii- specific IgG. A combination of these assays in the presence of clinical findings consistent with active Toxoplasma infection may predict the presence of toxoplasmic encephalitis. Moreover, detection of soluble SAG-1 in the CSF of these individuals appears consistent with active infection.

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