Oral Colonization of<i>Staphylococcus</i>Species in a Peritoneal Dialysis Population: A Possible Reservoir for PD-Related Infections?

Abstract

Peritoneal dialysis-related infections are important morbidity/mortality causes, being staphylococci the most prevalent agents. Since <i>Staphylococcus aureus</i> nasopharynx carriage is a known risk factor for PD infections and the oral cavity is a starting point for systemic diseases development, we aimed at comparing the oral staphylococci colonization between PD patients and controls and studying the association with PD-related infections. Saliva samples were plated in Mannitol salt, and isolates were identified by <i>DnaJ</i> gene sequencing. Staphylococci PD-related infections were recorded throughout the 4-year period following sample collection. <i>Staphylococcus</i> colonization was present in >90% of the samples from both groups (a total of nine species identified). PD patients presented less diversity and less prevalence of multispecies <i>Staphylococcus</i> colonization. Although all patients presenting <i>Staphylococcus epidermidis</i> PD-related infections were also colonized in the oral cavity by the same agent, only 1 out of 7 patients with ESI caused by <i>S</i>. <i>aureus</i> presented <i>S. aureus</i> oral colonization. Staphylococci are highly prevalent in the oral cavity of both groups, although PD patients presented less species diversity. The association between oral <i>Staphylococcus</i> carriage and PD-related infections was present for <i>S. epidermidis</i> but was almost inexistent for <i>S. aureus</i>, so, further studies are still necessary to evaluate the infectious potential of oral <i>Staphylococcus</i> carriage in PD.