Effect of endocervical specimen quality on detection of Chlamydia trachomatis and on the incidence of false-positive results with the Chlamydiazyme method

Abstract

zyme tested exactly as specified by the manufacturer. The effects (if any) of procedural alterations (necessary to determine specimen quality) on detection of C. trachomatis antigen from the other specimen were then established.

Influence of endocervical specimen adequacy on PCR and direct fluorescent-antibody staining for detection of Chlamydia trachomatis infections

“…There were 319 cervical specimens, 204 (63.9%) of which were graded as adequate by using the criteria of Kellogg et al (18,20,21). There were a total of 34 (10.7%) positive specimens by the DFA and/or the PCR assay (Table 1).…”

“…This study appeared to indicate, but did not definitively prove, that the same swab could be used to ascertain the adequacy of the cervical specimen before it is placed into the PCR transport medium for swirling. Other methods besides the DFA test have been used to assess the cellular components of the specimen; these include the Papanicolaou stain and Diff-Quick (Baxter Diagnostics, Inc., McGaw, Ill.) (18)(19)(20)(21). These methods are less costly and easier to use in a routine clinical laboratory than the DFA test, which requires an experienced microscopist.…”

“…The slides were evaluated for the presence of elementary bodies, columnar epithelial or metaplastic cells, polymorphonuclear cells, vaginal squamous epithelial cells, and erythrocytes. According to criteria set forth by Kellogg et al, a specimen was considered to be adequate on a cellular-component basis if it contained any columnar epithelial or metaplastic cells, with or without the other cells, or if it contained more than 100 erythrocytes per high-power field (18,20,21). Specimens containing this many erythrocytes could not be judged for the presence of columnar cells because the erythrocytes mask the other cells present in a sample (18).…”

“…Previously, a significant concern with regard to the performance of culture as well as nonculture assays has been the cellular adequacy of the cervical specimen, since chlamydiae are intracellular organisms which infect the columnar epithelial cells. The presence or absence of these cells has been shown to significantly affect the sensitivity and the specificity of the detection of chlamydia by the Chlamydiazyme assay (Abbott Diagnostics, Abbott Park, Ill.) as well as by direct fluorescent-antibody (DFA) staining (18,21,24). Additionally, the quality of the cervical specimen has been shown to affect the positivity rate of the commercial PCR assay (Roche Molecular Systems) (20).…”

Nachweis von Chlamydia psittaci in Vaginalausfluß von Rindern: Eine notwendige Erweiterung der bakteriologischen Diagnostik zur ätiologischen Klärung von Fruchtbarkeitsstörungen beim weiblichen Rind

“…Voraussetzung fur die Verknupfung der beiden Bedingungen war, den 'cut-off' des ELISA anhand der OD der prainkubierten Proben nach der oben aufgefuhrten Formel zu berechnen (TIJSSEN, 1985). (HIPP et al, 1987;KELLOGG et al, 1990;MARDH et al, 1990;MONCADA et al, 1990;MILLS et al, 1992;OLSEN und SAMBOL, 1993;WARREN et al, 1993) (MILLS et al, 1992).…”