High Frequency of <i>Chlamydia trachomatis</i> Mixed Infections Detected by Microarray Assay in South American Samples

<div><p><i>Chlamydia trachomatis</i> is one of the most common sexually transmitted infections worldwide. Based on sequence variation in the <i>omp</i>A gene encoding the major outer membrane protein, the genotyping scheme distinguishes 17 recognized genotypes, i.e. A, B, Ba, C, D, Da, E, F, G, H, I, Ia, J, K, L1, L2, and L3. Genotyping is an important tool for epidemiological tracking of <i>C</i>. <i>trachomatis</i> infections, including the revelation of transmission pathways and association with tissue tropism and pathogenicity. Moreover, genotyping can be useful for clinicians to establish the correct treatment when LGV strains are detected. Recently a microarray assay was described that offers several advantages, such as rapidity, ease of standardization and detection of mixed infections. The aim of this study was to evaluate the performance of the DNA microarray-based assay for <i>C</i>. <i>trachomatis</i> genotyping of clinical samples already typed by PCR-RFLP from South America. The agreement between both typing techniques was 90.05% and the overall genotype distribution obtained with both techniques was similar. Detection of mixed-genotype infections was significantly higher using the microarray assay (8.4% of cases) compared to PCR-RFLP (0.5%). Among 178 samples, the microarray assay identified 10 <i>omp</i>A genotypes, i.e. D, Da, E, F, G, H, I, J, K and L2. The most predominant type was genotype E, followed by D and F.</p></div

Type and origin of samples included in this study.

<p>Type and origin of samples included in this study.</p

Distribution of <i>C</i>. <i>trachomatis</i> genotypes according to type of sample.

<p>Distribution of <i>C</i>. <i>trachomatis</i> genotypes according to type of sample.</p

Characteristic of samples with mixed <i>omp</i>A genotype or conflicting results between genotyping methodologies.

<p>Characteristic of samples with mixed <i>omp</i>A genotype or conflicting results between genotyping methodologies.</p

<i>C</i>. <i>trachomatis</i> genotype distribution according to genotyping technique.

<p><i>C</i>. <i>trachomatis</i> genotype distribution according to genotyping technique.</p