Abstract
Forty-six Helicobacter cinaedi isolates from the same hospital were analyzed by multilocus sequence typing. Most H. cinaedi isolates exhibited clonal complex 9 and were mainly isolated from immunocompromised patients in the same ward. Three Helicobacter fennelliae isolates were obtained from the same ward and exhibited the same pulsed-field gel electrophoresis patterns. All isolates were resistant to clarithromycin and ciprofloxacin. H. cinaedi and H. fennelliae must be carefully monitored to prevent nosocomial infection.