Use of small fragment restriction endonuclease analysis (SF-REA) for epidemiological fingerprinting of Klebsiella oxytoca.

A group of infections caused by Klebsiella oxytoca was observed among preterm neonates in a neonatal intensive care unit (NICU) of a pediatric hospital in Osnabrück, Germany. The presence of unique antimicrobial susceptibility patterns among the bacterial isolates prompted an investigation to determine whether a limited spread of one single strain existed. All 4 K. oxytoca isolates from the NICU and, in addition, 50 epidemiologically non-related strains were fingerprinted by small fragment restriction endonuclease analysis (SF-REA). From an analysis of silver-strained EcoR I-generated restriction fragment patterns of whole-cell DNA in polyacrylamide gels, it was evident that the 4 NICU isolates were closely related, whereas all epidemiologically unrelated strains exhibited different patterns. From the results of this study, DNA fingerprinting by SF-REA is proposed as a useful tool for investigating the epidemiological relatedness of K. oxytoca strains of clinical and environmental origin.