Dry collection and culture methods for recovery of methicillin-susceptible and methicillin-resistant Staphylococcus aureus strains from indoor home environments

Staphylococcus aureus in home environments may serve as a reservoir for human colonisation, making sampling of indoor surfaces relevant to exposure assessment. Using laboratory experiments and application to homes of asthmatic children in Barbados, we characterise microbiological methods adapted for settings with transportation delays between sampling and initiation of culture. At the first field visit, 3/51 (6%) samples from 26 homes were S. aureus positive. From the MRSA protocol, one MRSA isolate and one MSSA isolate were cultured. From a subset of 16 samples cultured using the parallel MSSA protocol, one MSSA was isolated. At the second visit, MRSA was cultured from 2/19 (11%) common room surface samples (repository site) and from 3/19 (16%) pillow samples (site touched by the child). MSSA was cultured from 4/19 (21%) pillow samples. The child’s pillow was contaminated with S. aureus at 7 of 8 positive homes (88%).  MRSA was cultured from the top of the refrigerator in the same household 6 months apart.