Pseudooutbreak of Pantoea species bacteremia associated with contaminated cotton pledgets.

A total of 22 isolates of Pantoea strains, unusual causative agents of clinical infection, was isolated from blood cultures from 9 patients and 1 ear swab from 1 of the patients within a period of 1 month in a tertiary-care hospital. Pseudooutbreak was suspected because specimens were collected from a limited number of places and the patients did not show consistent signs or symptoms of bacterial sepsis. Enterobacterial repetitive intergenic consensus (ERIC) polymerase chain reaction (PCR) and partial 16S ribosomal DNA sequencing were performed to determine the clonal relationship among the isolates. Screening environmental cultures revealed that cotton pledgets were contaminated with Pantoea species. Molecular typing suggested that 2 different clones of Pantoea strains were responsible for the pseudooutbreak. Cotton materials may be a possible source of Pantoea pseudooutbreak. Molecular typing is useful for investigating epidemics and identifying unusual clinical isolates.