In gram stain the organisms shows rail track appearance or school of fish appearance.
Fine needle aspiration cytology:
This procedure draws the blood from the site of the infection and this is send to the laboratory for further investigation purposes.
Polymerase chain reaction:
It uses H.ducreyi DNA amplification and reveal the results.
H ducreyi is a fastidious bacterium requiring a relatively expensive nutritive base to grow on and is an extremely difficult organism to culture from clinical specimens in the hands of inexperienced laboratory staff. As a result, conventional laboratory culture facilities are often not available in STD clinics or simply not affordable in resource poor countries. In those clinical settings with laboratory support, clinicians are often faced with the dilemma of whether to treat a patient empirically for chancroid at the first visit or whether to request staff in their microbiology laboratory to provide a suitable medium with which to culture H ducreyi on a subsequent day in the hope that the patient is not lost to follow up. Even if culture facilities are available, it often takes several days for results to become available.
The role of Stuart’s, Amies’, and thioglycolate hemin based transport media has been evaluated as transport media for H ducreyi. Increased survival of H ducreyi from less than 24 hours to up to 4 days was seen when specimens were held at 4°C. The use of transport media in locations with a refrigeration facility may overcome the significant cost of distribution of culture media with short shelf lives to clinics where the disease is only seen sporadically. There did not appear to be any major advantage in the overall rate of recovery of H ducreyi using transport media compared to direct plating.