Three Cases of Bacteremia due to Helicobacter cinaedi Infection and the Usefulness of Gene Analysis of Isolated Bacteria

Helicobacter cinaedi is typically isolated from immunocompromised patients. Some reports of infection caused by H.cinaedi have been found in recent years. We experienced three cases of H.cinaedi bacteremia in one year and ten months in our hospital, although the detection of H.cinaedi in blood cultures is extremely rare. In case 1, a 77-year-old female had been treated with a steroid and immunosuppressive agent for interstitial pneumonia. In cases 2 and 3, two 71-year-old men had been treated with chemotherapy for lung cancer. Although the identification of the bacteria could not be performed by the culture method in the three cases, H.cinaedi bacteremia was diagnosed by a 16S rRNA gene sequencing analysis in case 1, and by nested PCR in cases 2 and 3. H.cinaedi bacteremia often tends to recur and also requires prolonged antimicrobial therapy. We believe that gene analysis is useful in the identification of H.cinaedi.