Objective Low-birthweight infants admitted to neonatal intensive care units are at high risk of hospital-acquired infections by opportunistic pathogens. The gut microbiota of preterm neonates lacks commensal bacteria providing a barrier against pathogens. We report a case of bacteremia due to Kosakonia cowanii in a preterm neonate.

Case Report A female baby of 680 g was delivered through a cesarean-section at 28 weeks of gestation due to intrauterine growth retardation and fetal rhythm abnormalities. On day 27, two blood cultures grew gram-negative bacilli in a context of functional ileus. No reliable identification could be obtained using matrix assisted laser desorption ionization-time of flight, biochemical reactions with the VITEK 2 GN ID card, or 16S rDNA sequencing. K. cowanii was finally identified by gyrB sequencing. The source of infection may have been either the central venous catheter or translocation from the gut microbiota. Evolution was favorable after 14 days of cefepime (combined with amikacin for 5 days) and central venous catheter removal.

Conclusion K. cowanii is a member of the Enterobacteriaceae family that was recently reclassified from the Enterobacter genus. Human infections due to K. cowanii are scarce and have mainly been associated with traumatic inoculation from plants or transient gut colonization. K. cowanii may be an underestimated opportunistic pathogen in susceptible populations such as preterm neonates.

目的 进入新生儿重症监护病房的低体重婴儿面临机会病原体在医院获得性感染的高风险。早产儿的肠道菌群缺乏共生细菌，可提供抵御病原体的屏障。我们报告了因早产儿Kosakonia cowanii引起的菌血症。

病例报告 由于子宫内生长迟缓和胎儿节律异常，在妊娠28周时通过剖宫产分娩了680 g的女婴。在第27天，两种血液培养物在功能性肠梗阻的情况下长出了革兰氏阴性杆菌。使用基质辅助的激光解吸电离飞行时间，与VITEK 2 GN ID卡进行的生化反应或16S rDNA测序无法获得可靠的鉴定。最后通过gyrB测序鉴定了考氏假单胞菌。感染的来源可能是中央静脉导管或来自肠道菌群的移位。头孢吡肟14天（与阿米卡星联合5天）并切除中心静脉导管后，其进化良好。

结论 Cowanii K.是肠杆菌科的一个成员，最近从肠杆菌属中重新分类。牛痢疾杆菌引起的人类感染很少，主要与植物的创伤性接种或短暂的肠道定植有关。在易感人群（如早产新生儿）中，考尼氏梭菌可能是一种被低估的机会病原体。