Molecular Characterization of Haemophilus ducreyi Isolates from Different Geographical Locations

Abstract

The technique of random amplified polymorphic DNA (RAPD) was adapted and optimized to study Haemophilus ducreyi isolates. A panel of 43 strains isolated from chancroid patients from different countries in Africa, Europe, North America, and Asia were characterized. The strains were also studied with respect to lipooligosaccharide (LOS) migration and immunoblotting patterns and the presence of cytolethal distending toxin genes. The RAPD method with the OPJ20 primer generated nine banding patterns (1 to 9). The majority of the isolates were clustered into two major profiles, 14 and 13 strains into profiles 1 and 2, respectively, and just a few strains revealed patterns 3 and 4. The isolates from Thailand were exceptional in that they showed greater diversity and were represented by six different RAPD patterns, i.e., patterns 3 and 5 to 9. The LOS migration and immunoblotting analyses revealed two different patterns, which indicated long and short forms of LOS; the former was found in 20/23 tested strains. Two strains that expressed the short form of LOS were grouped into RAPD pattern 4. The absence of cdtABC genes was observed in only 4/23 strains, and three of these isolates were assigned to RAPD pattern 4. Our results showed limited genotypic and phenotypic variations among H. ducreyi strains, as supported by the conserved RAPD and LOS profiles shared by the majority of the studied strains. However, the RAPD method identified differences between strains, including those from different geographic areas, which indicate the potential of RAPD as an epidemiological tool for the typing of H. ducreyi isolates in countries where chancroid is endemic.

Genotypic and Phenotypic Heterogeneity in Alicyclobacillus acidoterrestris: A Contribution to Species Characterization

“…In the last decade, RAPD PCR technique has been one of the most commonly used molecular techniques to develop DNA markers. RAPD PCR has found a wide range of applications in gene mapping, population genetics, molecular evolutionary genetics, plant and animal breeding [ 41 ]. In this study, Yamazaki protocol was employed to generate species-specific banding patterns in order to group strains in clusters [ 19 ].…”

On the evolution of the sexually transmitted bacteria Haemophilus ducreyi and Klebsiella granulomatis

“…The ability to change the surface antigens, for example, pili and lipooligosaccharide (LOS), to generate different antigenic variants is often used by STI pathogens to evade host immunity, for example, Neisseria gonorrhoeae . Molecular characterization of H. ducreyi isolates from different geographical locations was studied using random amplification of polymorphic DNA (RAPD) and showed little variation among H. ducreyi strains at the DNA level 13 . The proteomic studies of H. ducreyi indicated that their protein profiles were well conserved and were similar to strain 35000HP, suggesting little proteome diversity among isolates 14 .…”

Genetic characterization of Gac (Momordica cochinchinesis) accessions in Southern Vietnam by ISSR markers

“…However, these two studies mainly employed RAPD (Random Amplification of Polymorphic DNA) technique which is a simple, easy to implement technique and does not require genetic information for the subject. Nevertheless, this marker shows a low repeatability score and results in a high degree of reliance on reactive conditions such as DNA concentrations, the concentration of the components in the PCR reaction, the number of cycles of the reaction (Williams et al 1990;Mbwana et al 2006).…”