Wu Wenjing, Jiang Yongmei, Zhou Wei, Kuang Linghan, Ling Jiaji, Tang Yu, Liu Xingxin
Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, No.20, Section 3, Renmin South Road, Chengdu, Sichuan, 610041, P.R. China.
Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, Sichuan, 610041, China.
BMC Infect Dis. 2025 Sep 5;25(1):1101. doi: 10.1186/s12879-025-11501-5.
Early-onset neonatal sepsis (EOS) is a critical condition primarily caused by maternal-fetal transmission of bacterial pathogens during delivery, with Escherichia coli and Group B Streptococcus being the most prevalent. However, neonatal sepsis can also involve other rare bacteria, including Corynebacterium amycolatum, which was first described in 1988 and is widely recognized as an emerging pathogen in infectious diseases.
A male infant was admitted to the neonatal intensive care unit (NICU) due to premature birth and tachypnea. His mother had experienced premature rupture of membranes (PROM) 20 days prior. The infant's procalcitonin (PCT) level was significantly elevated, reaching 1.51 ng/ml. Chest X-ray revealed increased and blurred lung markings, slightly decreased lung transparency in both lung fields, with scattered ground-glass opacities, and a few fine granular shadows. Corynebacterium amycolatum was isolated from the blood cultures and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with 99.9% confidence. Antimicrobial susceptibility testing showed that the isolate was sensitive to penicillin, cephalosporins, and vancomycin, yet resistant to ciprofloxacin, clindamycin, and erythromycin. Empirical treatment with ampicillin and cefoperazone/sulbactam was initially started. Followed by ceftazidime based on susceptibility results, the infant's condition significantly improved, leading to discharge.
This case emphasizes the importance of recognizing C. amycolatum as a potential pathogen in neonatal sepsis, especially in preterm infants, and underscores the necessity of accurate identification methods such as MALDI-TOF MS to avoid misidentification. Given the severe clinical outcomes associated with this condition, heightened awareness and diagnostic precision are crucial for optimizing treatment strategies in neonatal intensive care units. This report highlights a rare case of EOS caused by C. amycolatum in a premature infant.
早发型新生儿败血症（EOS）是一种危急病症，主要由分娩期间细菌病原体的母婴传播引起，其中大肠杆菌和B族链球菌最为常见。然而，新生儿败血症也可能涉及其他罕见细菌，包括1988年首次描述的无枝菌酸棒状杆菌，它被广泛认为是传染病中的一种新兴病原体。
一名男婴因早产和呼吸急促入住新生儿重症监护病房（NICU）。他的母亲在20天前胎膜早破（PROM）。婴儿的降钙素原（PCT）水平显著升高，达到1.51 ng/ml。胸部X光显示肺纹理增多、模糊，双肺野肺透明度略有降低，有散在的磨玻璃样阴影和一些细颗粒状阴影。从血培养中分离出无枝菌酸棒状杆菌，并通过基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）以99.9%的置信度进行鉴定。药敏试验表明，分离株对青霉素、头孢菌素和万古霉素敏感，但对环丙沙星、克林霉素和红霉素耐药。最初开始使用氨苄西林和头孢哌酮/舒巴坦进行经验性治疗。根据药敏结果随后使用头孢他啶，婴儿的病情显著改善，最终出院。
本病例强调了认识到无枝菌酸棒状杆菌作为新生儿败血症潜在病原体的重要性，尤其是在早产儿中，并强调了诸如MALDI-TOF MS等准确鉴定方法对于避免错误鉴定的必要性。鉴于这种病症会带来严重的临床后果，提高认识和诊断准确性对于优化新生儿重症监护病房的治疗策略至关重要。本报告突出了一例由无枝菌酸棒状杆菌引起的早产儿EOS罕见病例。
