Hoehn T, Huebner J, Paboura E, Krause M, Leititis J U
Neonatal Intensive Care Unit, University Children's Hospital, Freiburg, Germany.
Crit Care Med. 1998 Nov;26(11):1857-62. doi: 10.1097/00003246-199811000-00028.
Besides its vasodilative actions, nitric oxide (NO) is also involved in host defense on a cellular level. We studied the antimicrobial properties of NO in concentrations used with inhaled NO therapy for the treatment of pulmonary hypertension in neonates.
In vitro study of bacterial growth of five species, with and without NO exposure.
Level IV neonatal intensive care unit at a university children's hospital.
In vitro bacterial cultures.
We tested ten different strains of five bacterial species (Staphylococcus aureus, Staphylococcus epidermidis, group B streptococcus [GBS/Streptococcus agalactiae], Escherichia coli, and Pseudomonas aeruginosa), derived from the tracheal isolates of ventilated premature and term infants. Cultures were exposed to three different concentrations of NO (40, 80, and 120 parts per million [ppm]) and bacterial growth was compared with the same strains incubated in ambient air for 24 hrs. After incubation (with or without NO), colony-forming units were counted.
Bacterial growth of S. aureus, E. coli, and P. aeruginosa was not reduced with the NO concentrations applied. The number of colony-forming units of S. aureus increased at 80 ppm of NO. Growth of S. epidermidis and GBS was significantly affected at 120 ppm, resulting in decreased numbers of colony-forming units as compared with controls exposed to ambient air.
We conclude that NO has a selective bacteriostatic effect on some of those bacteria most commonly cultured in tracheal specimens of premature infants and neonates. This effect appears to be dose-dependent and occurs in the upper range of dosages used with inhaled NO therapy. However, in the range of dosages applied in ongoing controlled trials of inhaled NO in neonates and premature infants (1 to 80 ppm), a bacteriostatic effect of NO is not to be expected.
除血管舒张作用外，一氧化氮（NO）在细胞水平上也参与宿主防御。我们研究了用于新生儿肺动脉高压吸入一氧化氮治疗的浓度下，NO的抗菌特性。
对五种细菌在有无NO暴露情况下的生长进行体外研究。
一所大学儿童医院的四级新生儿重症监护病房。
体外细菌培养物。
我们测试了五种细菌（金黄色葡萄球菌、表皮葡萄球菌、B组链球菌[GBS/无乳链球菌]、大肠杆菌和铜绿假单胞菌）的十种不同菌株，这些菌株来自通气的早产儿和足月儿的气管分离物。培养物暴露于三种不同浓度的NO（百万分之40、80和120[ppm]），并将细菌生长情况与在环境空气中培养24小时的相同菌株进行比较。培养（有或无NO）后，计算菌落形成单位。
所应用的NO浓度未降低金黄色葡萄球菌、大肠杆菌和铜绿假单胞菌的细菌生长。在80 ppm的NO浓度下，金黄色葡萄球菌的菌落形成单位数量增加。在120 ppm时，表皮葡萄球菌和GBS的生长受到显著影响，与暴露于环境空气的对照组相比，菌落形成单位数量减少。
我们得出结论，NO对早产儿和新生儿气管标本中最常培养的一些细菌具有选择性抑菌作用。这种作用似乎是剂量依赖性的，且发生在吸入NO治疗所用剂量的上限范围内。然而，在正在进行的新生儿和早产儿吸入NO对照试验所应用的剂量范围内（1至80 ppm），预计NO不会产生抑菌作用。
