Evaluation of the Strep A OIA® assay versus culture methods: Ability to detect different quantities of Group A Streptococcus

Susan Kuhn, H. Dele Davies, Gary Katzko, Taj Jadavji, Deirdre L. Church

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

The Strep A OIA® assay by Biostar (Boulder, Co., USA) is a unique optical immunoassay system for the rapid detection of Group A streptococcal carbohydrate. As part of a community-based pediatric cohort study of Group A Streptococcus (GAS) persistence following antibiotic therapy of pharyngitis, the performance of the Strep A OIA® assay was compared with the amount of growth from standard throat swab culture methods. A total of 363 throat swabs taken over the course of the study was evaluated from 248 children between 2 and 18 years of age. Two culture methods were performed: an agar plate with the throat swab using Columbia agar base with 5% sheep blood incubated under an anaerobic environment for 48 h and Todd-Hewitt broth (THB) enhancement. The Strep A OIA® was then performed. A total of 144 of 363 (39.7%) samples was positive for GAS by one or more of the laboratory tests across study visits: agar culture detected 132 of 144 (91.7%), THB culture detected 128 of 144 (88.9%), and the Strep A OIA® assay detected 129 of 144 (89.6%). Complete agreement among all three laboratory tests was found for 333 of 363 (91.7%) of the samples. Agar culture results were comparable to THB cultures with a sensitivity of 96.9%, specificity of 96.6%, a positive predictive value of 93.9%, and a negative predictive value of 98.3%. Although the performance of the Strep A OIA® assay had similar specificity (96.5%) and positive predictive value (93.8%) compared with the combined results of the two culture methods, the sensitivity (89.0%) and negative predictive value (93.6%) were lower. A significant difference (p < 0.001) was found in the ability of the Strep A OIA® assay to detect agar culture-positive swabs that had a light growth (1+ or 2+) (63.0%) versus a moderate (3+) or heavy (4+) growth (98.1%) of GAS. Although the Strep A OIA® assay allows GAS throat swab results to be reported an average of 24 h sooner than either of the cultures, the rapid assay was not as sensitive in detecting light growth GAS-positive cultures. Copyright (C) 1999 Elsevier Science Inc.

Original languageEnglish (US)
Pages (from-to)275-280
Number of pages6
JournalDiagnostic Microbiology and Infectious Disease
Volume34
Issue number4
DOIs
StatePublished - Aug 1 1999

Fingerprint

Streptococcus
Agar
Pharynx
Growth
Light
Optical Devices
Pharyngitis
Immunoassay
Sheep
Cohort Studies
Pediatrics
Anti-Bacterial Agents
Sensitivity and Specificity
Therapeutics

ASJC Scopus subject areas

  • Microbiology (medical)
  • Infectious Diseases

Cite this

Evaluation of the Strep A OIA® assay versus culture methods : Ability to detect different quantities of Group A Streptococcus. / Kuhn, Susan; Davies, H. Dele; Katzko, Gary; Jadavji, Taj; Church, Deirdre L.

In: Diagnostic Microbiology and Infectious Disease, Vol. 34, No. 4, 01.08.1999, p. 275-280.

Research output: Contribution to journalArticle

@article{71ee5a8f92724f088872abff6475ed67,
title = "Evaluation of the Strep A OIA{\circledR} assay versus culture methods: Ability to detect different quantities of Group A Streptococcus",
abstract = "The Strep A OIA{\circledR} assay by Biostar (Boulder, Co., USA) is a unique optical immunoassay system for the rapid detection of Group A streptococcal carbohydrate. As part of a community-based pediatric cohort study of Group A Streptococcus (GAS) persistence following antibiotic therapy of pharyngitis, the performance of the Strep A OIA{\circledR} assay was compared with the amount of growth from standard throat swab culture methods. A total of 363 throat swabs taken over the course of the study was evaluated from 248 children between 2 and 18 years of age. Two culture methods were performed: an agar plate with the throat swab using Columbia agar base with 5{\%} sheep blood incubated under an anaerobic environment for 48 h and Todd-Hewitt broth (THB) enhancement. The Strep A OIA{\circledR} was then performed. A total of 144 of 363 (39.7{\%}) samples was positive for GAS by one or more of the laboratory tests across study visits: agar culture detected 132 of 144 (91.7{\%}), THB culture detected 128 of 144 (88.9{\%}), and the Strep A OIA{\circledR} assay detected 129 of 144 (89.6{\%}). Complete agreement among all three laboratory tests was found for 333 of 363 (91.7{\%}) of the samples. Agar culture results were comparable to THB cultures with a sensitivity of 96.9{\%}, specificity of 96.6{\%}, a positive predictive value of 93.9{\%}, and a negative predictive value of 98.3{\%}. Although the performance of the Strep A OIA{\circledR} assay had similar specificity (96.5{\%}) and positive predictive value (93.8{\%}) compared with the combined results of the two culture methods, the sensitivity (89.0{\%}) and negative predictive value (93.6{\%}) were lower. A significant difference (p < 0.001) was found in the ability of the Strep A OIA{\circledR} assay to detect agar culture-positive swabs that had a light growth (1+ or 2+) (63.0{\%}) versus a moderate (3+) or heavy (4+) growth (98.1{\%}) of GAS. Although the Strep A OIA{\circledR} assay allows GAS throat swab results to be reported an average of 24 h sooner than either of the cultures, the rapid assay was not as sensitive in detecting light growth GAS-positive cultures. Copyright (C) 1999 Elsevier Science Inc.",
author = "Susan Kuhn and Davies, {H. Dele} and Gary Katzko and Taj Jadavji and Church, {Deirdre L.}",
year = "1999",
month = "8",
day = "1",
doi = "10.1016/S0732-8893(99)00027-9",
language = "English (US)",
volume = "34",
pages = "275--280",
journal = "Diagnostic Microbiology and Infectious Disease",
issn = "0732-8893",
publisher = "Elsevier Inc.",
number = "4",

}

TY - JOUR

T1 - Evaluation of the Strep A OIA® assay versus culture methods

T2 - Ability to detect different quantities of Group A Streptococcus

AU - Kuhn, Susan

AU - Davies, H. Dele

AU - Katzko, Gary

AU - Jadavji, Taj

AU - Church, Deirdre L.

PY - 1999/8/1

Y1 - 1999/8/1

N2 - The Strep A OIA® assay by Biostar (Boulder, Co., USA) is a unique optical immunoassay system for the rapid detection of Group A streptococcal carbohydrate. As part of a community-based pediatric cohort study of Group A Streptococcus (GAS) persistence following antibiotic therapy of pharyngitis, the performance of the Strep A OIA® assay was compared with the amount of growth from standard throat swab culture methods. A total of 363 throat swabs taken over the course of the study was evaluated from 248 children between 2 and 18 years of age. Two culture methods were performed: an agar plate with the throat swab using Columbia agar base with 5% sheep blood incubated under an anaerobic environment for 48 h and Todd-Hewitt broth (THB) enhancement. The Strep A OIA® was then performed. A total of 144 of 363 (39.7%) samples was positive for GAS by one or more of the laboratory tests across study visits: agar culture detected 132 of 144 (91.7%), THB culture detected 128 of 144 (88.9%), and the Strep A OIA® assay detected 129 of 144 (89.6%). Complete agreement among all three laboratory tests was found for 333 of 363 (91.7%) of the samples. Agar culture results were comparable to THB cultures with a sensitivity of 96.9%, specificity of 96.6%, a positive predictive value of 93.9%, and a negative predictive value of 98.3%. Although the performance of the Strep A OIA® assay had similar specificity (96.5%) and positive predictive value (93.8%) compared with the combined results of the two culture methods, the sensitivity (89.0%) and negative predictive value (93.6%) were lower. A significant difference (p < 0.001) was found in the ability of the Strep A OIA® assay to detect agar culture-positive swabs that had a light growth (1+ or 2+) (63.0%) versus a moderate (3+) or heavy (4+) growth (98.1%) of GAS. Although the Strep A OIA® assay allows GAS throat swab results to be reported an average of 24 h sooner than either of the cultures, the rapid assay was not as sensitive in detecting light growth GAS-positive cultures. Copyright (C) 1999 Elsevier Science Inc.

AB - The Strep A OIA® assay by Biostar (Boulder, Co., USA) is a unique optical immunoassay system for the rapid detection of Group A streptococcal carbohydrate. As part of a community-based pediatric cohort study of Group A Streptococcus (GAS) persistence following antibiotic therapy of pharyngitis, the performance of the Strep A OIA® assay was compared with the amount of growth from standard throat swab culture methods. A total of 363 throat swabs taken over the course of the study was evaluated from 248 children between 2 and 18 years of age. Two culture methods were performed: an agar plate with the throat swab using Columbia agar base with 5% sheep blood incubated under an anaerobic environment for 48 h and Todd-Hewitt broth (THB) enhancement. The Strep A OIA® was then performed. A total of 144 of 363 (39.7%) samples was positive for GAS by one or more of the laboratory tests across study visits: agar culture detected 132 of 144 (91.7%), THB culture detected 128 of 144 (88.9%), and the Strep A OIA® assay detected 129 of 144 (89.6%). Complete agreement among all three laboratory tests was found for 333 of 363 (91.7%) of the samples. Agar culture results were comparable to THB cultures with a sensitivity of 96.9%, specificity of 96.6%, a positive predictive value of 93.9%, and a negative predictive value of 98.3%. Although the performance of the Strep A OIA® assay had similar specificity (96.5%) and positive predictive value (93.8%) compared with the combined results of the two culture methods, the sensitivity (89.0%) and negative predictive value (93.6%) were lower. A significant difference (p < 0.001) was found in the ability of the Strep A OIA® assay to detect agar culture-positive swabs that had a light growth (1+ or 2+) (63.0%) versus a moderate (3+) or heavy (4+) growth (98.1%) of GAS. Although the Strep A OIA® assay allows GAS throat swab results to be reported an average of 24 h sooner than either of the cultures, the rapid assay was not as sensitive in detecting light growth GAS-positive cultures. Copyright (C) 1999 Elsevier Science Inc.

UR - http://www.scopus.com/inward/record.url?scp=0032764873&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032764873&partnerID=8YFLogxK

U2 - 10.1016/S0732-8893(99)00027-9

DO - 10.1016/S0732-8893(99)00027-9

M3 - Article

C2 - 10459477

AN - SCOPUS:0032764873

VL - 34

SP - 275

EP - 280

JO - Diagnostic Microbiology and Infectious Disease

JF - Diagnostic Microbiology and Infectious Disease

SN - 0732-8893

IS - 4

ER -