急性白血病患儿化疗后血流感染的临床特点、病原菌分布和耐药性分析

Analysis of clinical characteristics, distribution of pathogenic bacteria, and drug resistance of bloodstream infection in children with acute leukemia after chemotherapy

目的 探讨急性白血病患儿化疗后血流感染的临床特点、病原菌分布和耐药性。方法 选取化疗后发生血流感染的64例急性白血病患儿,收集临床资料,分析病原菌分布特点、药敏试验结果及预后。结果 64例患儿发生血流感染时均处于粒细胞缺乏期。64株病原菌中以革兰阴性(G-)菌为主,占51.6%(33/64),革兰阳性(G+)菌占45.3%(29/64),真菌占3.1%(2/64)。G-菌中前3位依次是肺炎克雷伯菌肺炎亚种、大肠埃希菌、产酸克雷伯菌,G+菌中前4位依次是G+杆菌、表皮葡萄球菌、人葡萄球菌人亚种、草绿色链球菌。51例急性淋巴细胞白血病(ALL)患儿的病原菌中G-菌占51.0%(26/51),G+菌占45.1%(23/51),真菌占3.9%(2/51);13例急性髓细胞性白血病(AML)患儿的病原菌中G-菌占53.8%(7/13),G+菌占46.2%(6/13)。64株病原菌中耐药菌占32.8%(21/64),其中G-菌中检出产超广谱β内酰胺酶大肠埃希菌占21.2%(7/33),产超广谱β内酰胺酶肺炎克雷伯菌占15.2%(5/33),耐碳青霉烯类肺炎克雷伯菌(CRKP)占9.1%(3/33);G+菌中检出耐甲氧西林凝固酶阴性葡萄球菌占34.5%(10/29),耐克林霉素葡萄球菌占17.2%(5/29),未检出耐利奈唑胺、万古霉素等葡萄球菌属菌株及肠球菌属菌株。G-菌感染和G+菌感染急性白血病患儿的降钙素原(PCT)水平比较,差异无统计学意义(P﹥0.05)。G-感染的急性白血病患儿白细胞介素-6(IL-6)水平明显高于G+菌感染患儿,差异有统计学意义(P﹤0.01)。63例患儿感染得到完全控制,1例放弃后续化疗出院。结论 急性白血病患儿血流感染以G-菌为主,ALL及AML患儿中G+菌与G-菌分布相当,IL-6在G-菌感染患儿中较G+菌感染患儿明显升高。

Objective To investigate the clinical characteristics, distribution of pathogenic bacteria, and drug resistance of bloodstream infection in children with acute leukemia after chemotherapy. Method A total of 64 children with acute leukemia who developed bloodstream infections after chemotherapy were selected. Their clinical data were collected, and the distribution characteristics of pathogenic bacteria, drug susceptibility test results, and prognosis of the children were also analyzed. Result All 64 children were in the stage of agranulocytosis when bloodstream infection occurred.Among the 64 strains of pathogenic bacteria, Gram-negative(G-) bacteria accounted for 51.6%(33/64), Gram-positive(G+) bacteria accounted for 45.3%(29/64), and fungi accounted for 3.1%(2/64). Among the G-bacteria, the top three pathogenic bacteria were Klebsiella pneumoniae subsp. pneumoniae, Escherichia coli, and Klebsiella oxytoca. Among the G+ bacteria, the top four pathogenic bacteria were G+ bacilli, Staphylococcus epidermidis, Staphylococcus hominis subsp. hominis, and Streptococcus viridans. Among the pathogenic bacteria in 51 children with acute lymphoblastic leukemia(ALL), G-bacteria accounted for 51.0%(26/51), G+ bacteria accounted for 45.1%(23/51), and fungi accounted for 3.9%(2/51). Among the pathogenic bacteria in 13 children with acute myeloid leukemia(AML), G-bacteria accounted for53.8%(7/13), and G+ bacteria accounted for 46.2%(6/13). Drug-resistant bacteria accounted for 32.8%(21/64) of the 64strains of pathogenic bacteria. Among them, Escherichia coli producing extended-spectrum β-lactamase in G-bacteria accounted for 21.2%(7/33), and Klebsiella pneumoniae producing extended-spectrum β-lactamase accounted for 15.2%(5/33), Carbapenem-resistant Klebsiella pneumoniae(CRKP) accounted for 9.1%(3/33), methicillin-resistant coagulase-negative staphylococci were detected in 34.5%(10/29) of G+ bacteria, and 17.2%(5/29) were found in clindamycin-resistant staphylococci, no Staphylococcus strains and Enterococcus strains resistant to linezolid and vancomycin were detected.There was no significant difference in the level of procalcitonin(PCT) between acute leukemia children with G-bacteria infection and G+ bacteria infection(P>0.05). The level of interleukin-6(IL-6) in children with acute leukemia with Gbacteria infection was significantly higher than that in children with G+ bacteria infection(P<0.01). The infection of 63children was completely controlled, while 1 case gave up follow-up chemotherapy and was discharged. Conclusion The bloodstream infection in children with acute leukemia was dominated by G-bacteria, there was no difference in the distribution of G+ bacteria and G-bacteria in children with ALL and AML. Level of IL-6 was significantly higher in G-bacteria infection children than in G+ bacteria infection children.