Kathleen Zani
University of Tennessee Le Bonheur Children's Hospital
Memphis
Disclosure information not submitted.
Ellie Margolis, MD, PhD
MD, PhD, Assistant Member
St. Jude Children's Research Hospital, United States
Disclosure information not submitted.
Nicholas Hysmith, MD
MD, Associate Professor, FAAP
University of Tennessee Health Science Center, United States
Disclosure information not submitted.
Title: Pathogenicity of the Nasal Microbiome of PICU Patients
Introduction/Hypotesis: Numerous studies have shown that methicillin-resistant Staphylococcus aureus (MRSA) colonization leads to increased incidence of MRSA infections in critically ill patients. MRSA is currently the only bacterial pathogen targeted in decolonization programs. Limited data exists on the nasal microbiome and the interplay with MRSA colonization and co-pathogens. We hypothesize that with the insult to the healthy immune system seen in critical illness, we will see a difference in the organisms that comprise the nasal microbiome in patients with suspected infections. The presence of MRSA will further alter the nasal microbiome.
Methods: A prospective, observational study was conducted in a single-center PICU at a tertiary care, free-standing children’s hospital. Patients aged 1 month to 17 years admitted from January 2021 onward were approached for enrollment. After obtaining informed consent, an anterior nasal swab was collected on post-operative patients with no evidence of infection (control group) and patients with concern for infection within five days of their admission to the PICU (experimental group). For MRSA, MSSA, and coagulase-negative methicillin-resistant Staphylococci (MR-CoNS) detection, multiplex PCR targeting the mecA, SCCmec orfX junction, cpn60, and 16S rRNA genes was quantified. For microbiome community discernment, the V3-V4 region of 16S rRNA will be amplified by Touchdown PCR method prior to sequencing.
Results: Preliminary data with 44 patients has 21 patients in the infection group and 23 patients in the post-operative group. 14/44 patients did not have baseline MRSA screening performed on admission to the PICU (31.8%), and only 4 patients were colonized with MRSA (9.1%). 8/21 patients in our infection group were PCR positive for MR-CoNS (38.1%), whereas this organism was identified in only 3/23 post-operative patients (13%).
Conclusions: The MRSA screen positivity was lower than expected based on community colonization rates. Additional education should be provided to ensure that all patients admitted to our PICU have routine MRSA screening performed. While not statistically significant, there was an increased incidence in MR-CoNS presence in our experimental group, which is notable due to its potential to cause infection, particularly in a hospital environment.