RESERVOIRS OF COAGULASE-NEGATIVE STAPHYLOCOCCI IN PRETERM INFANTS

This investigation was undertaken to determine the magnitude of, and i nterrelations between, reservoirs of coagulase negative staphylococci on infants' skin at various sites (including sites used for insertion of intravascular catheters) and in faeces during the first six months of life. Sites with large numbers of coagulase negative staphylococci were identified by sampling 16 skin sites and stools from 20 preterm n eonates at 8-30 days of life. A more detailed survey of numbers and ty pes of coagulase negative staphylococci in stool and at six skin sites of 10 preterm infants was then performed over the first six months of life. Isolates of coagulase negative staphylococci were collected and characterised by speciation, antibiotic susceptibility profiling, and plasmid restriction fragment length polymorphism analysis. Large, rel atively stable reservoirs were identified in the faeces, around the ea r, and in the axilla and nares. Skin on the forearm and leg, sites at which peripheral catheters are frequently sited, carried small unstabl e numbers of coagulase negative staphylococci, which were usually indi stinguishable from coagulase negative staphylococci isolated from othe r body sites on the same baby. Contamination of catheter insertion sit es with coagulase negative staphylococci from reservoir sites on the s ame baby could explain these observations. These data suggest that int erventions reducing cross-contamination between sites on the same baby might be as important in preventing coagulase negative staphylococcal bacteraemias as measures taken to prevent cross infection between bab ies. Procedures which are likely to result in heavy coagulase negative staphylococcal contamination of the hands of healthcare staff, such a s changing soiled nappies, should receive particular attention.