Department of Microbiology, Medical Faculty, University of Tartu, Tartu, Estonia.
J Hosp Infect. 2011 Aug;78(4):327-32. doi: 10.1016/j.jhin.2011.03.025.
This study aimed to examine the spectrum and time course of gut and nasopharyngeal colonization with Gram-negative micro-organisms, and to define the value of surveillance cultures in predicting late-onset sepsis in neonates admitted to neonatal intensive care units. Nasopharyngeal and rectal swabs were collected on admission and twice weekly thereafter in 278 neonates admitted within the first 72 h of life with risk factors of early-onset sepsis. Sterile body fluid cultures were obtained on admission and subsequently as clinically indicated. Approximately half of the rectal (693/1250, 55%) and nasopharyngeal (558/1153, 48%) samples but only 6% (32/555) of the sterile fluid samples in 26 patients were culture positive for Gram-negative organisms. In total, 2108 invasive and mucosal culture pairs were analysed. The overall sensitivity, specificity, and positive and negative predictive values of a mucosal sample to predict late-onset sepsis were 27%, 66%, 4% and 94%, respectively. Patients with pre-existing colonization with Klebsiella pneumoniae (P = 0.011), Klebsiella oxytoca (P = 0.002), Escherichia coli (P = 0.003), Stenotrophomonas spp. (P = 0.003) and Pseudomonas spp. (P ≤ 0.001) were more likely to develop late-onset sepsis. No such association was found for Acinetobacter baumannii, Serratia spp. or Enterobacter cloacae. In conclusion, routine mucosal cultures are inefficient for the prediction of Gram-negative late-onset sepsis in neonatal intensive care units. However, targeted screening for specific organisms in an outbreak (e.g. Klebsiella spp., E. coli, Stenotrophomonas spp. and Pseudomonas spp.) may offer an opportunity to improve infection control measures and enable timely initiation of appropriate antibiotic therapy.
本研究旨在检查革兰氏阴性微生物的肠道和鼻咽定植谱和时间进程，并确定监测培养物在预测入住新生儿重症监护病房的新生儿晚发性败血症中的价值。在 278 名生命最初 72 小时内入住并具有早发性败血症危险因素的新生儿中，入院时和此后每周两次采集鼻咽和直肠拭子。入院时以及随后根据临床需要获得无菌体液培养物。在 26 名患者中，约一半的直肠（693/1250，55%）和鼻咽（558/1153，48%）样本，但只有 6%（32/555）的无菌液样本培养出革兰氏阴性菌阳性。总共分析了 2108 个侵袭性和黏膜培养对。黏膜样本预测晚发性败血症的总体敏感性、特异性、阳性和阴性预测值分别为 27%、66%、4%和 94%。与克雷伯氏肺炎菌（P=0.011）、产酸克雷伯氏菌（P=0.002）、大肠杆菌（P=0.003）、嗜麦芽窄食单胞菌（P=0.003）和铜绿假单胞菌（P≤0.001）定植的患者更有可能发生晚发性败血症。对于鲍曼不动杆菌、沙雷氏菌属或阴沟肠杆菌，未发现这种关联。总之，常规黏膜培养对于预测新生儿重症监护病房的革兰氏阴性晚发性败血症效率低下。然而，在爆发时针对特定生物体进行靶向筛查（例如，克雷伯氏菌属、大肠杆菌、嗜麦芽窄食单胞菌和铜绿假单胞菌）可能为改善感染控制措施并能够及时开始适当的抗生素治疗提供机会。
