A Case Series of Elizabethkingia meningosepticum Bacteremia in the Cancer Population

Abstract

Elizabethkingia meningosepticum (E. meningosepticum) is a ubiquitous microorganism previously known as Chryseobacterium meningosepticum. It is emerging as a pathogen responsible for bacteremia in the immunocompromised population, particularly in cancer patients and those with a history of prolonged hospital stay and frequent instrumentations. A retrospective chart review of all cases over 10 years at the Moffitt Cancer Center showed a total of three patients with E. meningosepticum infection. The first patient (history of multiple myeloma) underwent endoscopy complicated by aspiration pneumonia and positive blood culture for E. meningosepticum infection. The second patient (current acute myelogenous leukemia) had neutropenic fever in the setting of a recent chest port infection. Blood culture from the chest port showed E. meningosepticum. The third patient (history of esophageal adenocarcinoma and acute myelogenous leukemia) had a history of recent pneumonia and cellulitis who presented with recurrent neutropenic fever. Blood culture was positive for E. meningosepticum. E. meningosepticum bacteremia has a high 28-day mortality rate (41%). As these three cases illustrate, early identification of the pathogen along with empiric treatment with a fluoroquinolone and/or minocycline is indicated to reduce morbidity and mortality.

A case of <italic>Elizabethkingia meningoseptica</italic> septicemia

“…伊丽莎白菌属是一种需氧、不发酵、过氧化氢酶阳性、氧化酶阳性、吲哚阳性的革兰阴性菌，广泛分布于土壤、植物、淡水、食品、医院环境、死水、内陆湿地和河流中。由于具备生物膜形成能力，可以在水槽和水龙头中定植，易导致医院和社区感染 ［ 1 - 2 ， 4 ］ 。近年来，随着高效、广谱抗菌药物的广泛应用，伊丽莎白菌感染的发病率逐年上升，多个国家和地区均报告了由该菌引起的医院暴发感染 ［ 5 ］ 。既往文献报道的大部分感染病例多在住院期间发生，其中超过85%的病例为有免疫抑制或有其他并发症的患者，如老年人、新生儿，以及有呼吸系统疾病、糖尿病、恶性肿瘤等基础疾病的患者 ［ 5 - 8 ］ ，文献报道其病死率为11.0%~66.6% ［ 4 ］ 。抗菌药物的不当使用是伊丽莎白菌感染最常见的危险因素，其他危险因素主要包括有中心静脉导管等内置物、中性粒细胞缺乏和休克等 ［ 4 ， 9 - 10 ］ 。本例患者为老年男性，有胃恶性肿瘤病史，发病前一个月行胃癌根治术，是伊丽莎白菌感染的高危人群。由于长期住院和频繁检查，有多种并发症的癌症患者出现脑膜脓毒性伊丽莎白金菌败血症呈上升趋势，对这一类人群临床医生须提高警惕，加以重视。…”

“…伊丽莎白菌株通常对β-内酰胺类、氯霉素类、大环内酯类、多黏菌素和氨基糖苷类抗菌药物耐药。根据体外药敏试验数据，甲氧苄啶-磺胺甲 唑、氟喹诺酮类、哌拉西林他唑巴坦、米诺环素是治疗脑膜脓毒性伊丽莎白金菌感染的首选经验性治疗药物 ［ 4 ， 8 ， 11 ， 14 ］ 。菌株对甲氧苄啶-磺胺甲 唑的敏感性报道不一，最低甚至为6%~10% ［ 17 - 18 ］ 。氟喹诺酮类药物可作为首选，归因于其药效学和药代动力学特性，以及在脑脊液中可达到比较好的药物浓度。然而，由于DNA回旋酶和/或拓扑异构酶Ⅳ基因的突变，该细菌可能对喹诺酮类药物产生抗药性。研究显示，相比左氧氟沙星敏感的患者，对左氧氟沙星耐药的患者14 d内病死率明显升高，因此，早期评估菌株对氟喹诺酮类药物的耐药情况对疾病防治具有重要意义 ［ 19 ］ 。虽然伊丽莎白金菌通常对四环素和多西环素耐药，但对米诺环素较为敏感（60%~100%） ［ 2 ］ 。由于伊丽莎白金菌的金属β-内酰胺酶基因携带率高，故大多数β-内酰胺类抗菌药物包括碳青霉烯类的体外活性较差。然而，β-内酰胺酶抑制剂显著增加了伊丽莎白金菌对头孢哌酮和哌拉西林的敏感性，据文献报道，伊丽莎白金菌对头孢哌酮舒巴坦和哌拉西林他唑巴坦的敏感率均较高，分别为88.5%和86.5% ［ 5 ］ 。本例患者经临床治疗效果证实，菌株对头孢哌酮舒巴坦、左氧氟沙星均敏感。此外，由于使用单药治疗时可存在迅速出现耐药性和治疗失败的风险，因此许多文献推荐选用联合抗感染治疗的方案，尽管这种联合治疗能否防止耐药性的发展尚不清楚。最常用的联合方案是哌拉西林他唑巴坦联合复方磺胺甲 唑，其次是哌拉西林他唑巴坦联合氟喹诺酮类 ［ 1 ］ 。此外也有研究建议采用万古霉素联合米诺环素或氟喹诺酮类的治疗方案 ［ 2 ］ 。…”

Current viewpoint on the epidemiology of nonfermenting Gram-negative bacterial strains

“…The clinical epidemiology of the emerging NFGNB from recent studies is summarized in Table 1[45,46,61,70,72–97].…”

A Case Series of Elizabethkingia Spp. Bacteremia in the Pediatric Population

“…They commonly affect immunocompromised individuals and premature newborns and can even cause outbreaks in the hospital. 2 , 3 Common diagnoses associated with Elizabethkingia species include pneumonia, urinary tract infections, meningitis, bacteremia, with other unusual presentations such as septic arthritis, peritonitis, and abscess. 4 , 5 Elizabethkingia infection, has an estimated 50% mortality rate among the pediatric population, but survivors of the infection may face complications such as hydrocephalus, motor deficits, seizures, and hearing loss.…”