Staphylococcal scalded skin syndrome in an extremely lowabirthaweight neonate: Molecular characterization and rapid detection by multiplex and realatime PCR of methicillinaresistant Staphylococcus aureus

• Published in: Pediatrics international 2011-04, Vol.53 (2), p.211-217
• Main Authors: Shi, Da, Ishii, Shiro, Sato, Takashi, Yamazaki, Hajime, Matsunaga, Masamichi, Higuchi, Wataru, Takano, Tomomi, Yabe, Shizuka, Tanaka, Kenichi, Yamamoto, Tatsuo
• Format: Article
• Language: English
• Subjects: Birth; Collagen; Drug resistance; Genotypes; Impetigo; Infants; Infection; Intensive care units; Low-birth-weight; Neonates; Pediatrics; Polymerase chain reaction; Primers; Probes; staphylococcal scalded skin syndrome; Staphylococcus aureus; Toxins; Virulence
• ISSN: 1328-8067; 1442-200X
• DOI: 10.1111/j.1442-200X.2010.03246.x

Background: Staphylococcal scalded skin syndrome (SSSS), caused by methicillin-resistant Staphylococcus aureus (MRSA) producing exfoliative toxin (ET), is a life-threatening infection for neonates in neonatal intensive care units (NICUs). SSSS in extremely low-birth-weight (ELBW) neonates is rare. A new class of MRSA (community-acquired MRSA, CA-MRSA) has been emerging in the community. The aim of this study was to characterize MRSA from an ELBW neonate with SSSS, and to develop rapid detection methods for SSSS-associated and emerging pediatric MRSA. Methods: An ELBW infant in the NICU developed SSSS on day 16 after birth. Isolated MRSA was genetically characterized and compared with CA-MRSA from bullous impetigo (biCA-MRSA), which is positive for the ET and collagen-adhesin (CNA) genes in many cases, and the Panton-Valentine leucocidin (PVL) gene rarely. Specific primers and probes for five virulence genes (for ETA, ETB, ETD, PVL, CNA) were designed for multiplex polymerase chain reaction (PCR) and real-time PCR. Results: MRSA strain H5 from SSSS exhibited the genotype (ST91, spa416[t375], agr3, SCCmecIVa, CoaI), and possessed the ETB and CNA genes, similar to ST91 biCA-MRSA (albeit with a divergence). Multiplex PCR detected the ETB and CNA genes of strain H5, and real-time PCR detected strain H5 at as low as 102CFU/mL. The assays were 100% specific and 100% sensitive, for the five virulence genes. Conclusion: ETB-positive ST91 MRSA, which was very similar to ST91 biCA-MRSA, was isolated from an ELBW infant with SSSS. The multiplex and real-time PCR assays specifically or quantitatively detected SSSS-associated and emerging pediatric MRSA.