Polymerase chain reaction for detection of Chlamydia trachomatis in conjunctival swabs

Abstract

Aims/background-OcularChlamydia trachomatis infection in the west occurs as ophthalmia neonatorum, acquired from the mother, or adult paratrachoma which is also associated with current genital tract infection. Accurate rapid laboratory diagnosis facilitates management, but the relative merits of antigen detection or DNA amplification tests are unresolved. Methods-A polymerase chain reaction (PCR) test was developed which amplified part of the plasmid shared by all the serovars of C trachomatis. Conjunctival swabs were tested using an in house immune dot-blot test (IDBT) for chlamydial lipopolysaccharide antigen, a commercial direct fluorescent antibody (DFA) test for chlamydial elementary bodies, and the PCR (DNA extracted using guanidinium lysis buVer). Results-The PCR achieved a detection limit of 100 plasmid copies (10 elementary bodies). In a combined retrospective and prospective clinical evaluation, the PCR and IDBT gave identical results with 21 positive and 57 negative eye swabs. However, interpretation of the DFA test required meticulous examination of the stained smear, sometimes by two microscopists. Conclusions-The PCR is likely to play an increasing role in the diagnosis of ocular C trachomatis infection because of its excellent sensitivity and specificity. (Br J Ophthalmol 1997;81:497-500)

Chlamydia trachomatis in the conjunctiva of children living in three rural areas in Mexico

“…Although DNA extraction and amplification (NAATs) are known to be more sensitive than Giemsa staining and microimmunofluorescence (MIF) for the detection of Chlamydia in human conjunctiva (20)(21)(22)(23), this study's funding would not cover the cost of the most sensitive options. Therefore, two samples were obtained from each child by scraping the conjunctiva.…”

Polymerase chain reaction based detection of fungi in infected corneas

“…[10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] Assays targeting Candida, Aspergillus, and Fusarium have been tested preliminarily in vitreous specimens, 28 29 and recently an assay using panfungal primers has been used more extensively in India. 30 A PCR assay has also been applied to detect Fusarium in rabbit corneal infections.…”

Diagnosis of chlamydial infection by direct enzyme-linked immunoassay and polymerase chain reaction in patients with acute follicular conjunctivitis

“…Fan et al [7] found that PCR was positive for Chlamydia trachomatis in 63% of 49 patients with follicular conjunctivitis, while Haller et al [8] found that 8.6% of their patients were positive to this microorganism by PCR and cell culture. Elnifro et al [6] reported as many as 27% of patients to be positive for Chlamydia by PCR. However, in all previous studies, no distinction was made between acute and chronic follicular conjunctivitis.…”