Chlamydia Trachomatis In Samples Research Articles

Letter to the editor: Chlamydia trachomatis samples testing falsely negative in the Aptima Combo 2 test in Finland, 2019.

Letter to the editor : Chlamydia trachomatis samples testing falsely negative in the Aptima Combo 2 test in Finland, 2019

Identification of a dominant Chlamydia trachomatis strain in patients attending sexual transmitted infection clinic and female sex workers in Tunisia using a high resolution typing method

BackgroundThe distribution of Chlamydia trachomatis genotypes in Tunisia was previously studied using the reverse hybridization method. In this study, we used multilocus sequence typing (MLST) to describe Chlamydia trachomatis genetic diversity among heterosexual populations in Tunisia. The obtained sequence types (STs) were compared with those from a heterosexual population from Amsterdam, the Netherlands. MethodsClinical Tunisian patients and female sex workers provided 107 Chlamydia trachomatis positive samples that were used for MLST. Samples from 256 heterosexuals visiting the Amsterdam STI clinic were included as a reference group. Six highly variable genetic regions including the ompA gene were amplified and sequenced. The ST numbers were derived from a Chlamydia typing database (http://mlstdb.uu.se) and used to draw minimum spanning trees. ResultsompA sequencing detected 7 genotypes among the Tunisian populations of which genotype E was the most prevalent (66.3%). This genotype E resolved into 23 different STs and among these the ST3 was predominant (53.5%). MLST displayed 43 STs, of which 28 (65%) were new in the database. Minimum spanning tree analysis of all Tunisian samples identified 4 clusters of which one formed a clonal cluster with samples presenting the most prevalent ST3. When comparing samples from the Tunisian and Dutch populations in one minimum spanning tree, there was little overlap between the Chlamydia trachomatis samples. ConclusionThe CT-hrMLST scheme allowed us to identify that the Tunisian distribution was dominated by one genotype E (ST3) strain which is also highly prevalent in many other countries worldwide.

Evaluation of High-Resolution Typing Methods for Chlamydia trachomatis in Samples from Heterosexual Couples

We aimed to compare conventional ompA typing of Chlamydia trachomatis with multilocus sequence typing (MLST) and multilocus variable-number tandem-repeat (VNTR) analysis (MLVA). Previously used MLST and MLVA systems were compared to modified versions that used shorter target regions and nested PCR. Heterosexual couples were selected from among persons with urogenital C. trachomatis infections visiting the sexually transmitted infection outpatient clinic in Amsterdam, The Netherlands. We identified 30 couples with a total of 65 C. trachomatis-positive samples on which MLST and MLVA for eight target regions were performed. All regions were successfully sequenced in 52 samples, resulting in a complete profile for 18 couples and 12 individuals. Nine ompA genovars from D to K, with two variants of genovar G, were found. The numbers of sequence type and MLVA type profiles were 20 for MLST and 21 for MLVA, and a combination of MLST and MLVA yielded 28 profiles, with discriminatory indexes (D) ranging from 0.95 to 0.99. Partners in 17 couples shared identical profiles, while partners in 1 couple had completely different profiles. Three persons had infections at multiple anatomical locations, and within each of these three individuals, all profiles were identical. The discriminatory capacity of all MLST and MLVA methods is much higher than that of ompA genotyping (D = 0.78). No genotype variation was found within the samples of the same person or from heterosexual couples with a putative single transmission. This shows that the chlamydial genome in clinical specimens has an appropriate polymorphism to enable epidemiological cluster analysis using MLST and MLVA.

Evaluation of Wondfo Chlamydia Trachomatis Rapid Diagnostic Cassette Based on Nano-Gold Immunochromatography Gssay（GICA）

This paper explains and demonstrates how to evaluate the sensitivity and specificity of wondfo chlamydia trachomatis rapid diagnostic cassette with GICA for detection of chlamydia trachomatis. 1026 genital specimens were collected from 630 females and 396 males.Two cassettes of wondfo and ClearView were used for the detection of Chlamydia trachomatis samples with blind detection simultaneously, inconsistent results by DFA. Sensitivity, specificity, positive predictive value and negative predictive value of wondfo cassette were analyzed. Out of 1026 samples detected, 83 were positive by both of wondfo and ClearView and 13 showed different results by wondfo and ClearView. Out of the 13 samples, the DFA confirmed 9 were positive. Therefore, 92 samples were truly positive and 934 were truly negative. The sensitivity, specificity, positive predictive value and negative predictive value of wondfo were 96.74% ,99.6% , 95.7% , 99.68%, respectively. The consistent rates of test results of the chlamydia trachomatis rapid diagnostic cassette , wondfo and ClearView, both were the same 98.64%. Of the three standard strains and two clinical strains of dilution test results showed that the sensitivity of wondfo slightly ClearView.The sensitivity and specificity of wondfo for the detection of Chlamydia trachomatis have the accept tability for clinical diagnostic and surveillance data.

Treatment of chlamydial conjunctivitis in newborns and adults with erythromycin and roxithromycin

A randomized single-blind study of the effects of erythromycin and roxithromycin on chlamydial conjunctivitis was performed on a group of patients, comprising 28 newborns and 27 adults. Treatment used was either 200 mg of erythromycin ethylsuccinate or 50 mg of roxithromycin daily, divided into two doses for the neonatal group or for the adult group, 1000 mg of erythromycin stearate or 300 mg of roxithromycin daily divided into two doses. All patients were treated for ten days. Clinically nine of the neonates and 13 of the adults had unilateral conjunctivitis, whilst the remaining cases were bilateral. At follow-up one month after commencing therapy, all but one (erythromycin-treated) of the 28 neonates and three (two of whom were erythromycin-treated) of the 27 adults were cured. However, 16 (nine neonates and seven adults) were culture-positive for Chlamydia trachomatis in samples from eye and/or nasopharynx. The culture-positive group comprised ten cases (four neonates and six adults) who had been treated with erythromycin and six (five neonates and one adult) with roxithromycin. No major side effects of the therapy were seen. The study indicates that there was no difference in the clinical cure rate for the two drugs either in neonates or in adults. However, the isolation rate of chlamydiae in the adult group differed, with 12 (92%) of the 13 roxithromycin-treated cases becoming culture-negative, whilst this was true for only eight (57%) of the 14 erythromycin-treated cases (P less than 0.007).