Department of Medical Microbiology and Infectious Diseases, Erasmus MC, University Medical Center Rotterdam, Dr. Molewaterplein 40, 3015, GD, Rotterdam, The Netherlands.
Department of Pediatrics, Division of Neonatology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
Antimicrob Resist Infect Control. 2020 Feb 22;9(1):39. doi: 10.1186/s13756-020-0699-8.
Neonatal Staphylococcus aureus (S. aureus) bacteremia is an important cause of morbidity and mortality. In this study, we examined whether methicillin-susceptible S. aureus (MSSA) transmission and genetic makeup contribute to the occurrence of neonatal S. aureus bacteremia.
A retrospective, single-centre study was performed. All patients were included who suffered from S. aureus bacteremia in the neonatal intensive care unit (NICU), Erasmus MC-Sophia, Rotterdam, the Netherlands, between January 2011 and November 2017. Whole-genome sequencing (WGS) was used to characterize the S. aureus isolates, as was also done in comparison to reference genomes. Transmission was considered likely in case of genetically indistinguishable S. aureus isolates.
Excluding coagulase-negative staphylococci (CoNS), S. aureus was the most common cause of neonatal bacteremia. Twelve percent (n = 112) of all 926 positive blood cultures from neonates grew S. aureus. Based on core genome multilocus sequence typing (cgMLST), 12 clusters of genetically indistinguishable MSSA isolates were found, containing 33 isolates in total (2-4 isolates per cluster). In seven of these clusters, at least two of the identified MSSA isolates were collected within a time period of one month. Six virulence genes were present in 98-100% of all MSSA isolates. In comparison to S. aureus reference genomes, toxin genes encoding staphylococcal enterotoxin A (sea) and toxic shock syndrome toxin 1 (tsst-1) were present more often in the genomes of bacteremia isolates.
Transmission of MSSA is a contributing factor to the occurrence of S. aureus bacteremia in neonates. Sea and tsst-1 might play a role in neonatal S. aureus bacteremia.
新生儿金黄色葡萄球菌（S. aureus）菌血症是发病率和死亡率的重要原因。在这项研究中，我们研究了耐甲氧西林金黄色葡萄球菌（MSSA）的传播和遗传构成是否导致新生儿金黄色葡萄球菌菌血症的发生。
进行了一项回顾性的单中心研究。所有在荷兰鹿特丹伊拉斯谟医学中心-索菲亚新生儿重症监护病房（NICU）因金黄色葡萄球菌菌血症住院的患者均被纳入研究。对金黄色葡萄球菌分离株进行全基因组测序（WGS），并与参考基因组进行比较。如果金黄色葡萄球菌分离株的遗传特征完全相同，则认为存在传播。
排除凝固酶阴性葡萄球菌（CoNS）后，金黄色葡萄球菌是新生儿菌血症最常见的原因。926 份新生儿阳性血培养物中，有 12%（n=112）培养出金黄色葡萄球菌。根据核心基因组多位点序列分型（cgMLST），共发现 12 个遗传上无法区分的 MSSA 分离株簇，共包含 33 个分离株（每个簇 2-4 个分离株）。在这 7 个簇中，至少有 2 个鉴定的 MSSA 分离株在一个月的时间内被采集。所有 MSSA 分离株均携带 6 个毒力基因，携带率为 98-100%。与金黄色葡萄球菌参考基因组相比，肠毒素 A（sea）和中毒性休克综合征毒素 1（tsst-1）的编码毒素基因在菌血症分离株的基因组中更为常见。
MSSA 的传播是导致新生儿金黄色葡萄球菌菌血症发生的一个因素。肠毒素 A 和中毒性休克综合征毒素 1 可能在新生儿金黄色葡萄球菌菌血症中起作用。
