Relatedness of coagulase-negative staphylococci causing bacteremia in low-birthweight infants.

OBJECTIVE

To investigate coagulase-negative staphylococcus (CONS) causing bacteremia in a neonatal intensive care unit (NICU).

DESIGN

A 14-month retrospective review of 47 infants in the NICU with CONS bacteremia was undertaken to determine CONS glycocalyx production, plasmid pattern, total DNA restriction fragment polymorphism, and clinical risk factors.

RESULTS

The isolates included 32 Staphylococcus epidermidis, six Staphylococcus haemolyticus, four Staphylococcus warneri, four Staphylococcus saprophyticus, and one Staphylococcus hominis. Sixty-five percent of S epidermidis produced glycocalyx; other species did not. Oxacillin resistance (52%) and the antibiograms of the CONS were consistent with other units in the hospital. Five similar CONS plasmid patterns were found among 16 isolates; 31 isolates had unique patterns. Extractions of total DNA from these isolates were digested using HindIII, HaeIII, and BstEII. Those with similar restriction fragment length patterns could not linked as nosocomially transmitted among infants with bacteremia.

CONCLUSION

Our observations suggest that multiple strains of CONS infect infants in the NICU who have similar risk factors. Although current infection control practices limit transmission of a pathogen, they do not prevent CONS bacteremias.