BLOOD CULTURE ISOLATES DURING 6 YEARS IN A TERTIARY NEONATAL INTENSIVE-CARE UNIT

Blood culture results obtained in a single tertiary neonatal intensive care unit are reviewed. In 4416 admissions occurring over 6 y me iden tified 206 positive cultures (4.7/100 admissions) growing 234 bacteria l and fungal isolates in 182 infants. Very early and early onset posit ive cultures comprised 17% and 22% each. Gram-positive bacteria domina ted in vera early (61%), early (91%) and late onset (78%) cultures wit h coagulase-negative staphylococci (CONS) as the most frequent isolate in all groups (22%, 46% and 55%, respectively). The 3 most frequent i solates following CONS were in very early onset cultures Escherichia c oli (19%), anaerobic bacteria (17%) and group B streptococci (GRS) (14 %), in early onset cultures Staphylococcus aureus (28%), Enterococci ( 7%), E. coli (6%) and Viridans streptococci (6%) and in late onset cul tures S. aureus (15%), Candida species (8%) and E. coil (5%). Infants less than or equal to 999 g birthweight, representing 6% of the admiss ions, contracted 37% of the positive blood cultures and nearly half (4 4%) of the CONS isolates. In these patients, a significant increase (p < 0.001) in the number of positive cultures/100 admissions and in the proportion of positive cultures in conjunction with an intravascular catheter mere seen (p < 0.001). An intravascular catheter was more oft en present when CONS mere isolated as compared to other organisms (p < 0.05). 23 positive cultures (11.2%), most frequently E, coli, mere as sociated with a fatal outcome. Our microbiological pattern is dominate d by a Gram-positive flora, which is in agreement with recent European and North American reports, but differs from earlier Scandinavian stu dies in the proportion of CONS and GBS reported.