The use of the PhP-KE biochemical fingerprinting system in epidemiological studies of faecalEnterobacter cloacaestrains from infants in Swedish neonatal wards

Abstract

SUMMARYThe PhenePlate (PhP) biochemical fingerprinting system is an automated method for typing of bacteria, based on the evaluation of the kinetics of biochemical reactions, performed in microtitre plates. In the present study the PhP-Klebsiella/Enterobacter (KE) system was evaluated for typing ofEnterobacter cloacaeand employed to study the epidemiology of faecalE. cloacaestrains isolated from infants in 22 Swedish neonatal wards. The PhP-KE system showed a high reproducibility and discrimination forE. cloacaeisolates. Among 64 epidemiologically unrelatedE. cloacaestrains, 49 distinct phenotypes were found, and the diversity index was 0·985.E. cloacaewas found as a part of the dominating Gram-negative aerobic bacterial flora in 83 out of 953 infants studied. The incidences ofE. cloacaecolonization varied between 0 and 35% in different wards, but in contrast to previous data forKlebsiellaspp. andEscherichia coli,there was little evidence of spread of particular strains in the wards. We also discuss two different measures of nosocomial transmission of bacterial strains: transmissible strains and epidemic index.