Molekulare Epidemiologie toxigener Corynebacterium diphtheriae Infektionen in Deutschland (Epidemiological analysis of toxigenic Corynebacterium diphtheriae infections in Germany using molecular typing methods)

 

Objectives::

Today Diphtheria is a rare disease in industrial countries but still a potential fatal threat to patients and public health we have to be aware of. In the 10 last years we observed increasing numbers of cutaneous diphtheria due to toxigenic C. diphtheriae and C. ulcerans strains. In 2015 the cases of cutaneous diphtheria among refugees and asylum seekers reported by Denmark, Germany, Switzerland and Sweden represented a significant outbreak of diphtheria among refugees in Europe. We used molecular typing methods such as multi locus sequence analysis and whole genome sequencing for the molecular characterization of toxigenic C. diphtheriae infections diagnosed in the National Consiliar Laboratory on Diphtheria.

Methods::

C. diphtheriae isolates were identified by using MALDI-TOF mass Spectrometry and the Api Coryne System. Strain toxigenicity was verified by PCR and a modified elek test. MLST and whole genome sequencing of the isolates was performed on a MiSeq Illumina.

Results::

We analysed 21 cases of toxigenic C. diphtheriae infections identified between 2011 and 2015 with travel history including isolates of refugees coming from Eritrea and Ethiopia. Patients mostly presented with wound infections (19/21 cases).

Conclusions::

Toxigenic C. diphtheriae associated wound infections are currently observed more frequently in Europe, due to travelling abroad and also due to refugees coming from endemic countries. MLST and whole genome sequencing offer the potential to describe outbreaks in very high resolution and are helpful tools in infection tracking and identification of transmission routes.