[Bacterial distribution and drug resistance of pathogens of blood stream infection in children with hematological malignancies after chemotherapy]

Distribution and drug resistance profiles of pathogens causing bloodstream infection after chemotherapy in children with acute lymphoblastic leukemia

OBJECTIVES

To study the changes in the distribution and drug resistance profiles of pathogens causing bloodstream infection after chemotherapy in children with acute lymphoblastic leukemia.

METHODS

The medical data were collected from the children with acute lymphoblastic leukemia who were admitted to the First Affiliated Hospital of Zhengzhou University between January 2015 and December 2020 and developed bloodstream infection after chemotherapy. The samples were divided into the first three years group and the next three years group according to the time of testing to investigate the differences in the distribution and drug resistance profiles of pathogens as time.

RESULTS

A total of 235 strains of pathogens were isolated, among which there were 159 Gram-negative strains (67.7%; mainly Escherichia coli and Klebsiella pneumoniae), 61 Gram-positive strains (26.0%; mainly Staphylococcus epidermidis), and 15 strains of fungi (6.4%; mainly Candida albicans). There were no significant differences between the first three years group and the next three years group in the detection rate of Gram-negative bacteria (68.8% vs 66.9%, P>0.05) or Gram-positive bacteria (29.2% vs 23.7%, P>0.05). Compared with the first three years group, the next three years group had significant increases in the detection rate of Streptococcus mitis (5.8% vs 0.0%, P<0.05) and fungi (9.4% vs 2.1%, P<0.05). There was no significant difference in the drug resistance rate of Gram-negative or Gram-positive bacteria between the two groups (P>0.05).

CONCLUSIONS

Enterobacteriaceae bacteria are the main pathogens of bloodstream infection after chemotherapy in children with acute lymphoblastic leukemia, while the detection rates of Streptococcus mitis and fungi tend to increase as time, which needs to be taken seriously in clinical practice.

[Analysis of pathogens and clinical characteristics of bloodstream infection in neutropenic children with hematological malignancies from 2014 to 2018]

目的

探讨儿童血液病患者在中性粒细胞缺乏（粒缺）期发生血流感染时的病原学分布、耐药情况，为该类患者合理使用抗菌药物提供数据支持。

方法

回顾性分析2014年1月至2018年12月中国医学科学院血液病医院收治的儿童血液病患者粒缺期发生血流感染时的临床特征、病原菌分布和药物敏感性数据。

结果

427例儿童血液病患者在粒缺期共发生537次血流感染，30 d全因死亡率为3.7%。其中44.7%例次血流感染的临床特征仅表现为发热，其病原菌以肠杆菌科细菌为主。血流感染常伴口腔黏膜、呼吸道及消化道症状，比例分别为20.7%、20.5%和14.3%。伴不同症状的血流感染病原菌分布不同（χ²=40.561，P=0.001）。共分离出550株病原菌，位于前5位的细菌分别为草绿色链球菌（109株，19.8%）、大肠埃希菌（99株, 18.0%）、表皮葡萄球菌（75株，13.6%）、肺炎克雷伯菌（67株，12.2%）和金黄色葡萄球菌（32株，5.8%）。耐药方面，肠肝菌科细菌及铜绿假单胞菌对于哌拉西林/他唑巴坦、碳青霉烯类药物的耐药率<5%。金黄色葡萄球菌中耐甲氧西林金黄色葡萄球菌（MRSA）的比例为9.7%。

结论

儿童恶性血液病患者粒缺期发生血流感染病原菌革兰阳性球菌与阴性杆菌比例大致相同，提示经验性抗菌药物使用应具有广谱性，常见分离菌耐药性仍处于较低水平，常用的碳青霉烯类、糖肽类、酶抑制剂复合物类药物如哌拉西林/他唑巴坦等仍具有较好效果。

[Clinical features and laboratory data analysis of Aeromonas bacteremia with hematological diseases]

目的

分析患有血液系统疾病患者气单胞菌血流感染的临床及实验室特征，为该类患者气单胞菌感染的防治提供依据。

方法

回顾性分析中国医学科学院血液病医院2014年1月至2018年12月5年发生气单胞菌血症的血液系统疾病患者，收集患者临床感染特征、菌株耐药性、发生季节、治疗及转归情况等相关信息。

结果

共42例血液病患者发生气单胞菌血流感染，其中39例（92.9%）血流感染发生于粒细胞缺乏（粒缺）期，平均发热时间为4（1~27）d，22例（52.4%）患者症状仅为发热，6例（14.3%）伴消化道症状（腹痛、腹泻、恶心、上消化道出血），8例（19.0%）伴肺部感染，13例（31.0%）伴皮肤软组织感染。7例（16.7%）患者死亡，且均伴皮肤软组织感染。气单胞菌对碳青霉烯类抗菌药物的耐药率为68.3%~70.7%，而对头孢菌素类、喹诺酮类及氨基糖苷类抗菌药物的耐药率均小于10%。

结论

血液系统疾病合并气单胞菌血流感染主要发生在粒缺期，主要以发热为主，当伴有皮肤软组织感染时死亡率高。抗菌药物选择应依据药敏结果，避免使用碳青霉烯类抗菌药物。