Detection of<i>Chlamydia trachomatis</i>Ocular Infection in Trachoma-Endemic Communities by rRNA Amplification

Yang, Joshua; Hong, Kevin C.; Schachter, Julius; Moncada, Jeanne; Lekew, Takele; House, Jenafir; Zhou, Zhaoxia; Neuwelt, Melissa D.; Rutar, Tina; Halfpenny, Colleen; Shah, N A Mohd; Whitcher, John P.; Lietman, Thomas M.

doi:10.1167/iovs.08-2247

Cited by 28 publications

(14 citation statements)

References 23 publications

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“…No manufacturer has sought FDA clearance with respect to detecting C. trachomatis in ocular samples. However, past experience has indicated that nucleic acid amplification tests (NAATs) perform very well when analyzing ocular samples, especially NAATs designed to detect rRNA (9). This study demonstrated that m2000 and GeneXpert performed with great accuracy when detecting C. trachomatis in ocular samples, indicating that either assay could be utilized for future trachoma studies.…”

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confidence: 88%

Comparison of the Abbott m 2000 RealTi m e CT Assay and the Cepheid GeneXpert CT/NG Assay to the Roche Amplicor CT Assay for Detection of Chlamydia trachomatis in Ocular Samples from Tanzania

et al. 2013

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The GeneXpert CT/NG assay (GeneXpert) and the Abbott m2000 RealTime CT (m2000) assay were compared to Amplicor for detecting ocular Chlamydia trachomatis. Discordant specimens were tested by the Aptima CT assay. The m2000 assay sensitivity was 100% (95% confidence interval [CI], 90% to 100%), and specificity was 98.46% (95% CI, 95.2% to 99.2%); GeneXpert sensitivity was 100% (95% CI, 90% to 100%), and specificity was 100% (95% CI, 98.1% to 100%). The m2000 and GeneXpert assays appear to perform as well as the Amplicor assay. The leading infectious cause of preventable blindness worldwide is trachoma, which occurs in resource-limited countries, including sub-Saharan Africa, and is caused by repetitive and untreated ocular Chlamydia trachomatis infections (1, 2, 3). The current reservoir of active disease and infection is in children; in villages where such infections are hyperendemic, C. trachomatis infections have been found in children who have been treated at least once though mass drug administration (MDA) (1, 4). PCR is considered to be the current gold standard test, although there is no defined gold standard test for ocular C. trachomatis infections (5, 6). The Roche Amplicor CT PCR assay (Roche Diagnostics, Indianapolis, IN) has been used in major trials to monitor infection following MDA (7). Testing for C. trachomatis infection is often difficult in regions associated with trachoma; the laboratory infrastructure is often deficient or nonexistent, and there is often a lack of trained personnel, equipment, funding, and cleanliness of testing areas. The Cepheid GeneXpert CT/NG Research Use Only (RUO) assay (GeneXpert) (Cepheid Inc., Sunnyvale, CA) is a rapid test designed to produce results relatively quickly, with little hands-on time required, and could be useful in areas where trachoma occurs. We evaluated the Abbott m2000 RealTime CT (m2000) assay (Abbott Molecular Diagnostics, Des Plaines, IL) for detection of C. trachomatis in ocular specimens from Tanzania as a means to reduce turnaround time for results and increase sample throughput. A first-generation GeneXpert CT/NG assay (GeneXpert) was subsequently evaluated as a potential method for testing ocular specimens in the field to expedite provision of immediate treatment of C. trachomatis ocular infections, pending demonstration of its performance in a laboratory setting.Duplicate ocular swab specimens (n ϭ 304) from the same eye were collected from children in Tanzania for the detection of C. trachomatis infection; collection was performed as previously described (8). Samples were shipped frozen in a dry state to the Johns Hopkins University (JHU) Research Laboratory in Baltimore, MD, and stored at Ϫ80°C until testing. Swabs were rehydrated with 1 ml of sterile molecular analysis-grade diethylpyrocarbonate (DEPC) water (Quality Biological, Inc., Gaithersburg, MD). One set of the duplicate specimens was tested by Amplicor (Roche Diagnostics) and GeneXpert (Cepheid) and, for discordance testing, by the GenProbe-Aptima CT (ACT) assay (Gen-Probe Hologi...

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confidence: 88%

Comparison of the Abbott m 2000 RealTi m e CT Assay and the Cepheid GeneXpert CT/NG Assay to the Roche Amplicor CT Assay for Detection of Chlamydia trachomatis in Ocular Samples from Tanzania

et al. 2013

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“…Existing nucleic acid amplification tests, considered a gold standard for a laboratory test of infection [11], [12], [13], involves instrumentation that is expensive and requires developed laboratories not widely available in many trachoma endemic countries. Thus, there is a need for a simple, inexpensive rapid test for CT that can be performed in the field in trachoma endemic areas.…”

Section: Introductionmentioning

confidence: 99%

Field Evaluation of the Cepheid GeneXpert Chlamydia trachomatis Assay for Detection of Infection in a Trachoma Endemic Community in Tanzania

et al. 2013

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PurposeTo determine the sensitivity, specificity, and field utility of the Cepheid GeneXpert Chlamydia trachomatis (CT) Assay (GeneXpert) for ocular chlamydia infection compared to Roche Amplicor CT assay (Amplicor).MethodsIn a trachoma-endemic community in Kongwa Tanzania, 144 children ages 0 to 9 were surveyed to assess clinical trachoma and had two ocular swabs taken. One swab was processed at Johns Hopkins University, Baltimore MD, using Amplicor, (Roche Molecular Diagnostics) and the other swab was processed at a field station in Kongwa using the GeneXpert Chlamydia trachomatis/Neisseria gonorrhoeae assay (Cepheid). The sensitivity and specificity of GeneXpert was compared to the Amplicor assay.ResultsOf the 144 swabs taken the prevalence of follicular trachoma by clinical exam was 43.7%, and by evidence of infection according to Amplicor was 28.5%. A total of 17 specimens (11.8%) could not be processed by GeneXpert in the field due to lack of sample volume, other specimen issues or electricity failure. The sensitivity of GeneXpert when compared to Amplicor was 100% and the specificity was 95%. The GeneXpert test identified more positives in individuals with clinical trachoma than Amplicor, 55% versus 52%.ConclusionThe GeneXpert test for C. trachomatis performed with high sensitivity and specificity and demonstrated excellent promise as a field test for trachoma control.

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“…Among most frequent extragenital manifestations of C. trachomatis are sexually acquired reactive arthritis (SARA), conjunctivitis and perihepatitis [1]. In most of the cases of ophthalmological manifestations C. trachomatis can be detected and/or isolated in the eye swabs [2]. It is believed that immunological and hormonal phenotype as well as some genotype characteristics, particularly expression of human leucocyte antigen B27, predetermine the severity of extragenital manifestations caused by C. trachomatis [3].…”

Section: Introductionmentioning

confidence: 99%

Chlamydia trachomatisgrowth inhibition and restoration of LDL-receptor level in HepG2 cells treated with mevastatin

Bashmakov¹,

Zigangirova

Pashko

et al. 2010

Comp Hepatol

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BackgroundPerihepatitis is rare but consistently occurring extragenital manifestation of untreated Chlamydia trachomatis infection. Despite of possible liver involvement in generalized C. trachomatis infection, the ability of the pathogen to propagate in the hepatic cells and its impact on liver functions is not thoroughly investigated. The effect of mevastatin, an inhibitor of 3-hydroxy-3-methylglutaryl CoA reductase, on C. trachomatis growth in human hepatoma cell line HepG2 has been studied. Bacterial growth was assessed by immunostaining with FITC-labeled monoclonal antibody against chlamydial lipopolysaccharide and by RT-PCR for two chlamydial genetic markers (16S rRNA and euo).ResultsChlamydial inclusion bodies were seen in approximately 50% of hepatocytes at 48 hours in the post infection period. Lysates obtained from infected hepatocytes were positive in the infective progeny test at 48 and especially in 72 hours after infection initiation. It has been shown that chlamydial infection in hepatocytes also leads to the decline of LDL-receptor mRNA which reflects infection multiplicity rate. Additions of mevastatin (1, 20 and 40 μM) 1 hour before inoculation restored and upregulated LDL-receptor mRNA level in a dose-dependent manner. Mevastatin treatment had no effect on internalization of chlamydial particles. However it reduced drastically the number of chlamydial 16S rRNA and euo transcripts as well as overall infection rate in HepG-2 cells. Complete eradication of infection has been seen by immunofluorescent staining at 40 μM mevastatin concentration, when expression level of chlamydial 16S rRNA and euo was undetectable. Lower concentration of mevastatin (20 μM) promoted euo expression level and the appearance of atypically small chlamydial inclusions, while there was a noticeable reduction in the number of infected cells and 16S rRNA transcripts.ConclusionsC. trachomatis can efficiently propagate in hepatocytes affecting transcription rate of some liver-specific genes. Ongoing cholesterol synthesis is essential for chlamydial growth in hepatocytes. Inhibitors of cholesterol biosynthesis can supplement conventional strategy in the management of C. trachomatis infection.

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Detection ofChlamydia trachomatisOcular Infection in Trachoma-Endemic Communities by rRNA Amplification

Cited by 28 publications

References 23 publications

Comparison of the Abbott m 2000 RealTi m e CT Assay and the Cepheid GeneXpert CT/NG Assay to the Roche Amplicor CT Assay for Detection of Chlamydia trachomatis in Ocular Samples from Tanzania

Comparison of the Abbott m 2000 RealTi m e CT Assay and the Cepheid GeneXpert CT/NG Assay to the Roche Amplicor CT Assay for Detection of Chlamydia trachomatis in Ocular Samples from Tanzania

Field Evaluation of the Cepheid GeneXpert Chlamydia trachomatis Assay for Detection of Infection in a Trachoma Endemic Community in Tanzania

Chlamydia trachomatisgrowth inhibition and restoration of LDL-receptor level in HepG2 cells treated with mevastatin

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