Clonality of slime-producing methicillin-resistant coagulase-negative staphylococci disseminated in the neonatal intensive care unit of a university hospital

Methicillin-resistant coagulase-negative staphylococci (MR-CNS) (n = 132), isolated from pre-term neonates, were analysed to determine their antibiotic resistance patterns, clonal distribution, biofilm production and the presence of the ica operon. All MR-CNS were multiresistant, and 89% produced slime. A major clone was identified (77 isolates) among 115 Staphylococcus epidermidis isolates. Ten of 16 Staphylococcus haemolyticus isolates also belonged to a single clone. Most (80%) slime-positive isolates possessed all the ica genes tested, while the remaining 23 (20%) had a variety of gene combinations. The entire ica cluster was detected in three of 15 slime-negative isolates. One major and two minor slime-positive, multiresistant MR-CNS clones had disseminated among hospitalised pre-term neonates.