Comparison of the Binax Legionella Urinary Antigen Enzyme Immunoassay (EIA) with the Biotest Legionella Urin Antigen EIA for Detection of Legionella Antigen in both Concentrated and Nonconcentrated Urine Samples

Abstract

We evaluated a newly commercial enzyme immunoassay (EIA) (BiotestLegionella Urin Antigen EIA; Biotest AG, Dreieich, Germany) for detection of antigens of all Legionella pneumophilaserogroups with a relatively wide spectrum of cross-reactivity as well as antigens of other Legionella spp. by comparing its sensitivity and specificity with those of an EIA for detection ofL. pneumophila serogroup 1 antigen (Legionella urinary antigen EIA; Binax, Portland, Maine). Both tests were performed with both concentrated and nonconcentrated urine samples. We also evaluated the capabilities of both EIAs to detect extracted soluble antigens of American Type Culture Collection (ATCC) Legionella strains (L. pneumophila serogroups 1 to 14, L. bozemanii, and L. longbeachae). The sensitivity of the Biotest EIA was 66.66% in nonconcentrated urine and 86.66% in concentrated urine. The sensitivity of the Binax EIA was 63.76% and 88.88% in nonconcentrated and concentrated urine, respectively. The specificity was 100% in nonconcentrated and concentrated urine for both assays. The Binax EIA and Biotest EIA detected extracted soluble antigens of L. pneumophila serogroups 1 to 14 and L. bozemanii ATCC strains. The cross-reactions observed with the Binax EIA were probably due to common epitopes directly related to lipopolysaccharide. Further studies are required to determine the usefulness of the Binax EIA for detection of urinary antigens fromLegionella species and serogroups other than L. pneumophila serogroup 1. The Biotest EIA proved to be as rapid, sensitive, and specific as the Binax EIA for the diagnosis of legionellosis. Concentration of antigen present in urine increased the sensitivities of both techniques with no reduction in specificity.

Evaluation of the SAS Legionella Test, a new immunochromatographic assay for the detection of Legionella pneumophila serogroup 1 antigen in urine

“…Based on prospective and retrospective studies using data from isolated cases, moderate-to-high urinary antigen test sensitivities have been described [4,6,[11][12][13][14][15]. These variations may be explained by differences in test and patient characteristics, the serogroup infecting the patient, the timing of collection during the course of the illness, and whether the urine was concentrated before testing.…”

Dual detection of Legionella pneumophila and Legionella species by real-time PCR targeting the 23S-5S rRNA gene spacer region

“…The urine antigen (UA) test is increasingly used by clinicians in the diagnosis of LD, but it is limited to the detection of L. pneumophila serogroup 1 [10]. Extensive use of the UA test has resulted in a decrease in the use of other diagnostic methods, thus reducing the frequency of identification of species other than L. pneumophila serogroup 1 [11].…”

Insuffisance Respiratoire Aiguë chez le patient immunodéprimé : Quelle approche diagnostique ?

“…La présence de ces anticorps semble témoigner d'une exposition préalable à Legionella spp. La détection urinaire de l'antigène est positive 1 à 3 jours après le début de l'infection et reste positive jusqu'à 1 an après dans une petite proportion de patients [35,36]. L'atout majeur de l'antigénurie est sa spécificité supérieure à 99 % [37].…”