This study compared conventional ompA genotyping of Chlamydia trachomatis with multilocus sequence typing (MLST) and multilocus typing (MLT) DNA microarray. DNA extracts of 104 C. trachomatis positive specimens were analyzed by ompA sequencing and MLST and of these 76 by MLT array. Obtained MLST sequence types (STs) were compared to sequences in the database http://mlstdb.uu.se. The resolution obtained for MLST (35 STs) was 2.1 higher than for ompA sequencing (17 variants) and 1.3 higher than MLT array (27 MLT groups). Among the 104 samples the predominant genotype E could be divided into 5 ompA variants and 23 STs of which 16 had not been reported in previous studies. The most common STs, ST3 and ST56, were identified as founders and are common in several countries on a global scale. The MLST and the MLT array provided similar strain discrimination capacity and showed considerably higher resolution than conventional ompA sequencing.
Keywords: Chlamydia trachomatis; DNA array; Genotyping; MLST; ompA.