An Outbreak of Neonatal Toxic Shock Syndrome‐Like Exanthematous Disease (NTED) Caused by Methicillin‐Resistant Staphylococcus aureus (MRSA) in a Neonatal Intensive Care Unit

Abstract

Neonatal toxic shock syndrome‐like exanthematous disease (NTED) is a new entity of methicillin‐resistant Staphylococcus aureus (MRSA) infection. Most of NTED cases reported previously in the literature were sporadic ones. In the present report, we describe an outbreak of NTED that occurred in a neonatal intensive care unit (NICU) between April, 1999 and April, 2000 in Japan. All MRSA strains isolated from 14 patients (6 NTED, 2 infections and 6 colonizations) in this outbreak belonged to the group of coagulase II and produced toxic shock syndrome toxin 1 (TSST‐1). Of these, 14 strains produced staphylococcal enterotoxin C (SEC). No other superantigenic toxins were produced by these strains. The pulsed field gel electrophoresis (PFGE) patterns of genomic DNA digested with SmaI were indistinguishable each other due to no band shifting in all of the 13 strains except for strain O‐21 and M56. Strain M56 was different from the dominant type in the positions of only 2 bands, whereas the pattern of strain O‐21 had no similarity with the other pattern, suggesting that this outbreak was associated with the spread of a unique MRSA strain in the NICU. Two‐dimensional electrophoresis (2‐DE) analysis of exoproteins revealed that the patterns of these 14 strains were very indistinguishable to each other, and that these strains produced very large amounts of TSST‐1 and SEC3 subtype superantigens, as measured with computer‐assisted image analysis of the intensity of 2‐DE spots. The 2‐DE gel of O‐21 showed the different pattern from the others. These results as well as the profiles of toxin production also supported the conclusion drawn from PFGE analysis. Based on these results, the involvement of TSST‐1 and SEC3 in the pathogenesis of NTED is discussed.

Prevalence of Toxic Shock Syndrome Toxin 1 (TSST-1)-Producing Strains of Staphylococcus aureus and Antibody to TSST-1 among Healthy Japanese Women

“…Reports from Japan over the past few years have shown TSST-1 to be responsible for a large number of NTED cases, a disease of neonates that lack maternal antibody to the toxin. In this light, the relative infrequency of mTSS in Japan is especially striking (22,29,48,49).…”

“…There have been numerous reports, however, of neonatal TSS-like exanthematous disease (NTED), which is typically characterized by fever, erythema, and thrombocytopenia (49). Most reported cases of NTED have been caused by TSST-1-producing, methicillinresistant strains of Staphylococcus aureus (MRSA) (22,29,32,33), and susceptibility to this toxin was indicated by low levels of antibody directed against TSST-1 (32).…”

Treatment Strategies for Methicillin-Resistant Staphylococcus aureus Infections in Pediatrics

“…Fever has been observed in 40-50% of the by an MRSA TSS-like syndrome that was observed in a neonatal cases, [21,33] but the majority of children appear to be well and have outbreak. [45] TSS is by definition a toxin-mediated illness related to S. In the past 5 years, standard empiric therapy has changed for aureus strains that produce TSST-1. The common denominators these infections because of the emergence of MRSA.…”

HealthCare–Associated Infections in the Nursery

“…Staphylococcus aureus has frequently been identified as a cause of nosocomial infection and outbreaks in wellinfant nurseries and NICUs. Methicillin-resistant S. aureus (MRSA) has become a serious nosocomial pathogen, and outbreaks have been reported in many areas of hospitals, including nurseries [89][90][91]. With the emergence of community strains of MRSA, nosocomial transmission of MRSA with the molecular phenotype of either community-associated or hospital-associated strains has been shown [92,93].…”

“…With the emergence of community strains of MRSA, nosocomial transmission of MRSA with the molecular phenotype of either community-associated or hospital-associated strains has been shown [92,93]. In addition to the usual manifestations of neonatal nosocomial infection, S. aureus HAIs (caused by methicillin-sensitive strains or MRSA strains) can manifest as skin infections [94], bone and joint infections [95], parotitis [96], staphylococcal scalded skin syndrome [97,98], toxic shock syndrome [89], and disseminated sepsis.…”