A Case of Persistent Diarrhea in a Man with the Molecular Detection of Various Campylobacter species and the First Isolation of candidatus Campylobacter infans

A man with a well-controlled HIV infection, previously diagnosed with lymphogranuloma venereum and treated for Hodgkin’s lymphoma, was suffering from chronic diarrhea. He travelled to Indonesia in the month prior to the start of complaints. Over a 15-month period, sequences related to Campylobacter troglodytis/upsaliensis, C. pinnepediorum/mucosalis/concisus and C. hominis were detected by 16S rRNA qPCR-based assays in various stool samples and in a colon biopsy. Culture revealed the first isolation of “candidatus Campylobacter infans”, a species identified recently by molecular methods only. The patient was treated with azithromycin, ciprofloxacin and tetracycline. To identify potential continuous exposure of the patient to Campylobacter, stool samples of the partner and the cat of the patient were analyzed and C. pinnepediorum/mucosalis/concisus and C. helveticus, respectively, were detected. The diversity in detected species in this immunocompromised patient with a lack of repeatedly consistent findings resulted in the conclusion that not any of the Campylobacter species was the primary cause of the clinical condition. This study shows the challenges in detection and interpretation of diagnostic results regarding Campylobacter.