Nosocomial outbreak of Sphingomonas paucimobilis Bacteremia in a Hemato/Oncology unit

Nosocomial Sphingomonas paucimobilis infections can arise from contaminated water and the contaminated hands of hospital staff. Within a 1-month period, we isolated six S. paucimobilis strains, including four from blood cultures of four patients and two from hospital environment specimens including tap water and a bathtub in a hemato/oncology unit. We described here these strains' molecular epidemiological analyses by pulsed-field gel electrophoresis (PFGE) and antibiotic susceptibilities by E-test. Although clinical and environmental isolates yielded three different antibiotic resistances and PFGE patterns, all four clinical strains had an identical pattern by both methods. Thus, the isolated clinical strain clone could be traced neither to health care workers nor to environmental samples. It was concluded that S. paucimobilis strains can cause outbreaks in hemato/oncology units. We did not demonstrate genetic relatedness between clinical and environmental isolates by PFGE, but did find PFGE a useful identification technique for epidemiological investigation.