A case of cutaneous listeriosis in a man

Abstract number: P646

Zdovc I., Zelenik K., Pate M., Avbersek J., Lusicky M., Krt B., Ocepek M.

Objectives: In humans, listeriosis caused by Listeria monocytogenes usually occurs in certain high-risk groups (neonates, pregnant women, immunocompromised adults) but rarely in persons without predisposing factors. Sepsis, meningitis and meningoencephalitis are common features of listeriosis in humans; rare cutaneous form of the disease is linked mainly to occupational hazards (veterinarians, laboratory workers).

A case of L. monocytogenes skin infection in a man is presented. A 54-year-old male veterinary practitioner developed pustular changes on the skin of arms and hands after assisting the delivery of stillborn calf. During the parturition one of his gloves tore and he continued with exposed hands. He suspected the bacterial infection to be the cause for stillbirth therefore he took a sample of placenta and sent it to the laboratory for bacteriological examination. Later, pustular changes developed on his skin; the swabs were taken for bacteriology and L. monocytogenes was isolated. The patient was treated successfully with amoxicillin and clavulanic acid.

Methods: Cultivation, identification, serotyping and genotyping of the strains from pustulae and placenta were performed. As a genotyping method, pulsed-field gel electrophoresis (PFGE) was used and performed following the CDC standardised PulseNet protocol for L. monocytogenes using restriction endonucleases AscI and ApaI. The genotyping results were analysed using BioNumerics software (Applied Maths).

Results: Pure cultures of small haemolytic colonies suspicious of Listeria spp. were grown after 24h incubation on sheep blood agar from all specimens. The colonies were identified as L. monocytogenes with biochemical kit API Listeria (BioMerieux). Serotyping resulted in serotype 4b in all isolates. The cleavage of the DNA with both AscI and ApaI exhibited identical PFGE restriction patterns of all strains suggesting the zoonotic transmission of the infection with L. monocytogenes.

Conclusion: To the best of our knowledge, this is the first case of cutaneous listeriosis where the evidence for zoonotic transmission of L. monocytogenes was supported by genotyping methods.