Department of Neonatology, KK Women's & Children's Hospital, Singapore.
Duke-NUS Medical School, Singapore.
Ann Acad Med Singap. 2023 Nov 29;52(11):561-569. doi: 10.47102/annals-acadmedsg.2023190.
Recent reports have described the increasing predominance of Gram-negative organisms among invasive bacterial infections affecting preterm infants. This changing pattern of infections is concerning due to the spread of antibiotic resistance among Gram-negatives.
We conducted a single-centre, retrospective cohort study involving very-low-birthweight (VLBW) (<1500 grams) infants born <32 weeks gestation, with culture-proven infections (blood, urine, cerebrospinal fluid [CSF]) in the neonatal intensive care unit from 1 January 2005 to 31 October 2017.
A total of 278 out of 2431 (11.4%) VLBW infants born <32 weeks gestation developed 334 infections, i.e. 52 (15.6%) early-onset infections (EOIs) and 282 (84.4%) late-onset infections (LOIs). The overall incidence decreased from 247 to 68 infections per 1000 infants over the study period, corresponding to reductions in LOI (211 to 62 infections per 1000 infants). A total of 378 bacteria were isolated, i.e. Gram-negatives accounted for 70.9% (45 of 59 [76.3%] EOI; 223 of 319 [69.9%] LOI). Specific resistant organisms were noted, i.e. Methicillin-resistant Staphylococcus aureus (8 of 21 S. aureus infections [38.1%]); Cephalosporin-resistant Klebsiella (18 of 62 isolates [29.0%]) and multidrug-resistant [MDR] Acinetobacter (10 of 27 isolates [37.0%]). MDR organisms accounted for 85 of 195 (43.6%) Gram-negative infections from the bloodstream and CSF. Based on laboratory susceptibility testing, only 63.5% and 49.3% of infecting bacteria isolated in blood were susceptible to empiric antibiotic regimens used for suspected EOI and LOI, respectively.
Gram-negative bacteria are the predominant causative organisms for EOI and LOI and are frequently MDR. Understanding the pattern of antimicrobial resistance is important in providing appropriate empiric coverage for neonatal infections.
最近的报告描述了侵袭性细菌感染在影响早产儿的病例中，革兰氏阴性菌的比例不断增加。这种感染模式的变化令人担忧，因为革兰氏阴性菌的抗生素耐药性正在传播。
我们进行了一项单中心、回顾性队列研究，纳入了 2005 年 1 月 1 日至 2017 年 10 月 31 日在新生儿重症监护病房出生<32 周、胎龄<32 周、有培养证实的感染（血液、尿液、脑脊液）的极低出生体重（VLBW）（<1500 克）婴儿。
共有 2431 名出生<32 周的 VLBW 婴儿中，278 名（11.4%）婴儿发生 334 例感染，即 52 例（15.6%）早发性感染（EOI）和 282 例（84.4%）晚发性感染（LOI）。在研究期间，总体发病率从每 1000 例婴儿 247 例感染降至 68 例感染，相应的 LOI 发病率从每 1000 例婴儿 211 例感染降至 62 例感染。共分离出 378 株细菌，即革兰氏阴性菌占 70.9%（59 株中的 45 株[76.3%]EOI；319 株中的 223 株[69.9%]LOI）。还注意到特定的耐药菌，即耐甲氧西林金黄色葡萄球菌（21 株金黄色葡萄球菌感染中的 8 株[38.1%]）；头孢菌素耐药肺炎克雷伯菌（62 株分离株中的 18 株[29.0%]）和多药耐药[MDR]鲍曼不动杆菌（27 株分离株中的 10 株[37.0%]）。血流和脑脊液中革兰氏阴性菌感染的 MDR 菌占 195 株的 85 株（43.6%）。根据实验室药敏试验，血培养分离出的感染菌中，分别只有 63.5%和 49.3%对疑似 EOI 和 LOI 经验性抗生素方案敏感。
革兰氏阴性菌是 EOI 和 LOI 的主要病原体，且经常是多药耐药菌。了解抗生素耐药模式对于为新生儿感染提供适当的经验性覆盖非常重要。
