Prolonged silent carriage, genomic virulence potential and transmission between staff and patients characterize a neonatal intensive care unit (NICU) outbreak of methicillin-resistant Staphylococcus aureus (MRSA)

Abstract

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen in neonatal intensive care units (NICU) that confers significant morbidity and mortality. Objective: Improving our understanding of MRSA transmission dynamics, especially among high-risk patients, is an infection prevention priority. Methods: We investigated a cluster of clinical MRSA cases in the NICU using a combination of epidemiologic review and whole-genome sequencing (WGS) of isolates from clinical and surveillance cultures obtained from patients and healthcare personnel (HCP). Results: Phylogenetic analysis identified 2 genetically distinct phylogenetic clades and revealed multiple silent-transmission events between HCP and infants. The predominant outbreak strain harbored multiple virulence factors. Epidemiologic investigation and genomic analysis identified a HCP colonized with the dominant MRSA outbreak strain who cared for most NICU patients who were infected or colonized with the same strain, including 1 NICU patient with severe infection 7 months before the described outbreak. These results guided implementation of infection prevention interventions that prevented further transmission events. Conclusions: Silent transmission of MRSA between HCP and NICU patients likely contributed to a NICU outbreak involving a virulent MRSA strain. WGS enabled data-driven decision making to inform implementation of infection control policies that mitigated the outbreak. Prospective WGS coupled with epidemiologic analysis can be used to detect transmission events and prompt early implementation of control strategies.

Linking preterm infant gut microbiota to nasograstric enteral feeding tubes: exploring potential interactions and microbial strain transmission

“…The results of our work suggest that staphylococci, which are widespread in the hospital environment and in the skin and mucosal surfaces of the hospital staff (53)(54)(55)(56), may play a pioneering role in the NEFT colonization process. The main species found in these settings (Staphylococcus epidermidis and other coagulase-negative species, Staphylococcus aureus) can form biofilms within medical devices, including NEFTs.…”

Environmental Persistence of Staphylococcus capitis NRCS-A in Neonatal Intensive Care Units: Role of Biofilm Formation, Desiccation, and Disinfectant Tolerance

“…Despite preventative measures to avoid pathogen cross-contamination, such as frequent surface decontaminations and cautious handwashing, the presence of pathogens and outbreaks involving different bacterial species including NRCS-A still occur in NICUs ( 10 , 43 – 49 ). Innovative procedures of decontamination are needed to be more efficient than disinfectants in combatting bacterial persistence in NICUs and especially biofilm-embedded and adherent strains.…”

Genetic Diversity, Antibiotic Resistance, and Virulence Gene Features of Methicillin-Resistant Staphylococcus aureus Epidemics in Guiyang, Southwest China

“…Virulence factors are the main factors involved in the colonization and pathogenicity of pathogenic bacteria and facilitate invasive infection, 36 , 50 , 51 causing a strong inflammatory response and promoting infection syndrome. 4 , 38 , 51 In addition, virulence factors help bacteria form biofilm for stable attachment, ensuring pathogen survival and infection.…”

“…Increasing antibiotic resistance is a global public health problem. MRSA prevalence has increased in recent years.- 4,23,27,[36][37][38] In addition, antibiotic resistance and MRSA prevalence trends change dynamically according to different medication use habits and time periods. Thus, monitoring the prevalence and antibiotic resistance as well as timely updates are valuable and essential.…”