Look Who’s Talking: Host and Pathogen Drivers of Staphylococcus epidermidis Virulence in Neonatal Sepsis

Abstract

Preterm infants are at increased risk for invasive neonatal bacterial infections. S. epidermidis, a ubiquitous skin commensal, is a major cause of late-onset neonatal sepsis, particularly in high-resource settings. The vulnerability of preterm infants to serious bacterial infections is commonly attributed to their distinct and developing immune system. While developmentally immature immune defences play a large role in facilitating bacterial invasion, this fails to explain why only a subset of infants develop infections with low-virulence organisms when exposed to similar risk factors in the neonatal ICU. Experimental research has explored potential virulence mechanisms contributing to the pathogenic shift of commensal S. epidermidis strains. Furthermore, comparative genomics studies have yielded insights into the emergence and spread of nosocomial S. epidermidis strains, and their genetic and functional characteristics implicated in invasive disease in neonates. These studies have highlighted the multifactorial nature of S. epidermidis traits relating to pathogenicity and commensalism. In this review, we discuss the known host and pathogen drivers of S. epidermidis virulence in neonatal sepsis and provide future perspectives to close the gap in our understanding of S. epidermidis as a cause of neonatal morbidity and mortality.

Interspecies relationships between nosocomial pathogens associated to preterm infants and lactic acid bacteria in dual-species biofilms

“…Currently, the use of some LAB strains to minimize the colonization of surfaces by potentially pathogenic species is gaining attention ( Stone et al., 2020 ; D’Accolti et al., 2022 ). The colonization of clinical devices, as NEFTs, by strains of K. pneumoniae and S. marcescens is especially relevant as these microorganisms are frequently associated with outbreaks in NICUs ( Marchant et al., 2013 ; Escribano et al., 2019 ; Moles et al., 2019 ; Chen et al., 2020 ; Hassuna et al., 2020 ; Joubert et al., 2022 ). The knowledge provided by this study would guide the selection of potentially probiotic strains that are already sharing the same niche with the pathogens for future applications in Neonatology.…”

The Role of Coagulase-Negative Staphylococci Biofilms on Late-Onset Sepsis: Current Challenges and Emerging Diagnostics and Therapies

“…Indeed, the skin microbiome of neonates is not fully established, evolving during the first year of life or even beyond [ 70 ]. The colonization of neonates in the first hours/days is most likely the result of contact with medical staff, equipment and their parents [ 72 ]. The composition of the newborn microbiome is determined by the previous administration of antibiotics, by modes of feeding and delivery [ 71 , 73 , 74 , 75 ] and, very likely, depends on geographical and ethnic factors [ 63 ].…”

The Transcription Factor SpoVG Is of Major Importance for Biofilm Formation of Staphylococcus epidermidis under In Vitro Conditions, but Dispensable for In Vivo Biofilm Formation

“…Staphylococcus aureus and S. epidermidis are the most frequently reported bacterial species causing implantable device related infections [ 2 ]. Identification of the latter bacterial species—a highly abundant commensal of the human skin flora [ 3 ]—in positive blood cultures was considered for a long time primarily as contamination, however, in recent years, S. epidermidis has been also recognized as a relevant source for implantable device-related bloodstream infections [ 4 ] and late-onset neonatal sepsis [ 5 ]. In fact, S. epidermidis is nowadays identified as the most important cause of nosocomial catheter related blood stream infections (CRBSI) in numerous countries including Argentina [ 6 ], Germany [ 7 ], Portugal [ 8 ], South Africa [ 9 ], Switzerland [ 10 ], and the United States [ 11 ].…”