Strongyloides stercoralis : identification of antigens in natural human infections from endemic areas of the United States

Siddiqui, Afzal A.; Koenig, Nora M.; Sinensky, Michael; Berk, Steven L.

doi:10.1007/s004360050314

Cited by 31 publications

(36 citation statements)

References 20 publications

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“…15 The reactivities of S. stercoralis-infected sera with larval proteins by Western blotting showed a similar pattern of recognition to the prominent 28-, 31-, and 41-kD proteins as in previous studies. [17][18][19] We also observed an additional reactivity to the 205-kD protein in about half of the infected subjects. Interestingly, the sensitivity to the 41-kD protein (81.8%) was greater than that of the ELISA, indicating that the high cut-off level might have overshadowed the sensitivity of the ELISA in our study.…”

Section: Resultsmentioning

confidence: 69%

“…The high sensitivity of detecting the 41-kD protein was also found in previous studies. [17][18][19] This observation suggests that purified or recombinant 41-kD protein may be useful in the ELISA. We did see a few weak reactivities with the 41-kD protein in the sera of other helminthic infections and parasite-free individuals.…”

Section: Resultsmentioning

confidence: 93%

“…Preliminary data have indicated that immunodominant proteins (apparent molecular weights of 41, 31, and 28 kD) of S. stercoralis filariform larvae are recognized by strongyloidiasis sera with high sensitivity and specificity. [17][18][19] It is generally known that the detection of S. stercoralis larvae in the feces may be very difficult, especially in chronic cases with low-level infection. 2,20 This problem may be in part attributed to irregular and low output of the larvae in the feces.…”

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confidence: 99%

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Fluctuations of larval excretion in Strongyloides stercoralis infection.

Uparanukraw¹,

Phongsri²,

Morakote³

1999

The American Journal of Tropical Medicine and Hygiene

133

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Abstract. Follow-up stool examinations were carried out on two groups of the subjects who were screened negative (group 1) or positive (group 2) for Strongyloides stercoralis by the agar plate culture. This technique could detect S. stercoralis larvae in 87.5-96.4% of the subjects in group 2 and 0-5.9% of the subjects in group 1 on various days of the eight-week and four-week follow-up periods, respectively. The detection rate on each day of examination was not statistically different from that on the first day in both groups. Quantitative measurement of S. stercoralis larvae excreted in the feces of the subjects in group 2 by the standard direct smear method of Beaver and others revealed slight to marked fluctuations of the larval output in individual subjects. From the results of both stool examination methods, it could be implied that 52% of S. stercoralis-infected individuals had low-level infection.Strongyloides stercoralis is an intestinal nematode of humans with a rather unique biology in that it has a free-living phase outside the host. Human infections due to S. stercoralis are distributed primarily throughout tropical and subtropical regions of the world. 1 Reports of S. stercoralis infections in non-endemic countries were from the ex-prisoners of the World War II 2,3 or the Southeast Asian immigrants. 4 The clinical spectrum of strongyloidiasis varies from asymptomatic infection, to mild symptomatic abdominal and skin diseases, to fatal disseminated infection in immunosuppressed patients. 5 The reported prevalences of S. stercoralis infection are difficult to ascertain and may have been underestimated because most infections are with low larval densities in the feces.1 They are also difficult to compare because of the difference in the coprologic methods used to detect the larvae. Earlier methods for the diagnosis of S. stercoralis infection such as the simple direct smear and formalin-ether concentration are often unreliable because of their relatively low sensitivity. In recent years, the agar plate culture technique has been introduced and found to give consistently higher sensitivity (78-100%) than simple direct smear (0-52% sensitivity) and formalin-ether concentration method (13-55% sensitivity). 6-10 Several immunologic methods have also been used in the diagnosis of strongyloidiasis. Currently, the most widely used method has been the ELISA using crude antigen extracts of filariform larvae as antigens. Most reports on the ELISA for strongyloidiasis have shown consistently high sensitivity, but the specificity has varied widely due to different criteria used for the selection of uninfected individuals. [11][12][13][14][15][16] Recently, Western blot analysis has been applied to the immunodiagnosis of strongyloidiasis. Preliminary data have indicated that immunodominant proteins (apparent molecular weights of 41, 31, and 28 kD) of S. stercoralis filariform larvae are recognized by strongyloidiasis sera with high sensitivity and specificity. [17][18][19] It is generally known that the detection o...

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Section: Resultsmentioning

confidence: 69%

Section: Resultsmentioning

confidence: 93%

mentioning

confidence: 99%

See 1 more Smart Citation

Fluctuations of larval excretion in Strongyloides stercoralis infection.

Uparanukraw¹,

Phongsri²,

Morakote³

1999

The American Journal of Tropical Medicine and Hygiene

133

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“…SERA AND ANTIBODY PURIFICATION S eventy eight different sera samples were obtained from patients admitted to the James H. Quillen Veterans Affairs Medical Center, Mountain Home, TN (Siddiqui et al, 1997). All of these patients had a significant number of Strongyloides larvae in their stool samples and were diagnosed with only S. stercoralis infection.…”

Section: Methodsmentioning

confidence: 99%

“…The ELISA for the detection of serum IgG against crude extract of filariform larvae can be 85 % sensitive in detecting S. stercoralis infection (Neva et al, 1981). However, the specificity of this ELISA is limited (Conway et al, 1994;Siddiqui et al, 1997). Therefore identification of bona fide S. stercoralis antigens is essential for the development of a sensitive and specific diagnostic test.…”

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confidence: 99%

Isolation of a cDNA encoding an IgG immunoreactive antigen (zinc finger protein) ofStrongyloides stercoralis

2001

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Summary:A full length cDNA encoding an IgG immunoreactive antigen of Strongyloides stercoralis is described. A clone containing 1,328 bp insert was selected following screening of S. stercoralis cDNA library with an IgG fraction obtained from a pool of 78 S. stercoralis positive human sera samples. The nucleotide sequence of the 1,328 bp insert was found to be 70.5 % A/T, reflecting a characteristic A/T codon bias of S. stercoralis. The nucleotide sequence of this insert identified a cDNA coding for a zinc finger protein.

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Identification of a 26-kDa protein fraction as an important antigen for application in the immunodiagnosis of strongyloidiasis

et al. 2007

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Strongyloidiasis caused by the intestinal nematode Strongyloides stercoralis typically occurs in the asymptomatic form. The definitive diagnosis is usually done by detection of larvae on fecal samples. However, as the parasite load is often low in most cases, microscopy is not usually sensitive and specific, and diagnosis becomes extremely difficult. Thus, development of reliable serological methods is imperative. In the present study, a diversity of epitopes from S. stercoralis larva were characterized by analysis of reactivity with serum samples obtained from individuals with and without the infection by using Western blot technique. A total of 91 serum samples belonging to 5 groups were analyzed. Different reactivity profiles were observed, representing recognition of proteins with molecular mass varied from 6 to 129 kDa. A protein band of approximately 26 kDa presented a high frequency of reactivity with serum samples from the strongyloidiasis patients group (18/23). Reactivity with this protein band was also observed in only 7 of 64 non-infected individuals or individuals infected with other helminthes. Reactivity with 2 other bands, 1 of approximately 33 kDa and a duplet of approximately 21 kDa, were also found in high frequency (17/23 and 9/23, respectively). However, reactivity with these bands was also observed in all the other serum groups studied. The results indicate that the 26-kDa band maybe be an important tool for the development of diagnostic techniques for strongyloidiasis.

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Strongyloides stercoralis : identification of antigens in natural human infections from endemic areas of the United States

Cited by 31 publications

References 20 publications

Fluctuations of larval excretion in Strongyloides stercoralis infection.

Fluctuations of larval excretion in Strongyloides stercoralis infection.

Isolation of a cDNA encoding an IgG immunoreactive antigen (zinc finger protein) ofStrongyloides stercoralis

Identification of a 26-kDa protein fraction as an important antigen for application in the immunodiagnosis of strongyloidiasis

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