Genomic and Epidemiological Features of Two Dominant Methicillin-Susceptible Staphylococcus aureus Clones from a Neonatal Intensive Care Unit Surveillance Effort
Medini K. Annavajhala, Nicole Kelly, Wenjing Geng, Samantha A. N. Ferguson, Marla J. Giddins, Emily Grohs, Alexandra Hill‐Ricciuti, Daniel A. Green, Lisa Saiman, Anne‐Catrin Uhlemann
Abstract
Methicillin-susceptible Staphylococcus aureus (MSSA) is a significant pathogen in neonates. However, surveillance efforts in neonatal intensive care units (NICUs) have focused primarily on methicillin-resistant S. aureus (MRSA), limiting our understanding of colonizing and infectious MSSA clones which are prevalent in the NICU. Here, we identify two dominant colonizing MSSA clones during an 18-month surveillance effort in a level III to IV NICU, ST398 and ST1898. Using genomic surveillance and phylogenetic analysis, coupled with epidemiological investigation, we found that these two sequence types had distinct modes of spread, namely the suggested exchange with community reservoirs for ST398 and the contribution of antibiotic resistance to dissemination of ST1898 in the health care setting. This study highlights the additional benefits of whole-genome surveillance for colonizing pathogens, beyond routine species identification and genotyping, to inform targeted infection prevention strategies.