摘要
目的通过分析败血症患儿的感染病原菌类型和耐药率、血清指标及毒力因子,为患儿败血病治疗提供参考依据。方法选取本院败血症患儿65例,通过血液培养分离出无乳链球菌,提取DNA,进行血清指标检测、毒力基因检测和产物测序。结果患儿CRP、PCT和WBC(×109)的平均值分别为(45.62±8.96)mg/L、(2.85±0.51)ng/ml和(16.21±1.91)×10~9,均显著高于对照组幼儿(P<0.05)。65例患儿的标本中共计分离出68株,革兰阳性菌55株,革兰阴性菌13株。革兰阳性菌中检出的主要菌种为无乳链球菌、表皮葡萄球菌、金黄色葡萄球菌和肠球菌。革兰阴性菌检出的主要菌种分别为大肠埃希菌、肺炎克雷伯菌和粘质沙雷菌。主要菌种为无乳链球菌,检出22株。临床分离出的55株革兰阳性菌对红霉素(83.64%)和四环素(70.91%)耐药程度较高,对环丙沙星(20.00%)和利福平(12.73%)耐药程度较低,对万古霉素不产生耐药性。无乳链球菌对红霉素(81.82%)和四环素(54.55%)有较高的耐药程度,对青霉素、头孢唑啉、环丙沙星、利福平和万古霉素未产生耐药性。革兰阴性菌对阿莫西林(61.54%)、阿莫西林+棒酸(38.46%)、头孢吡肟(38.46%)、哌拉西林(69.23%)、哌拉西林+他唑巴坦(30.77%)、环丙沙星(23.08%)和亚胺培南(23.08%)均产生了不同程度耐药。大肠埃希菌对阿莫西林(50.00%)和哌拉西林(50.00%)产生了耐受性,对阿莫西林+克拉维酸和哌拉西林+他唑巴坦未产生耐受性。22株无乳链球菌中共检出6个型别,分别为ST1、ST10、ST12、ST17、ST19和ST27,构成比分别为18.18%、31.82%、13.64%、22.73%、13.64%和4.55%。22株无乳链球菌中共检出5个血清型别,分别为Ia、Ib、Ⅱ、Ⅲ和Ⅴ,构成比分别为13.64%、45.45%、9.09%、13.64%和18.18%。22株无乳链球菌中均检出cylE、cfb、hylB和lmb基因。bac基因检出率45.45%,Ib型菌株bac基因全部为阳,其他类型菌株为阴性。fbsA基因检出率45.45%。结论新生儿败血症是新生儿危重急症,细菌对临床常用药物产生了一定程度的耐受性,应该进行病原菌分型及耐药试验;败血症患儿主要感染无乳链球菌,其毒力因子参与败血症致病过程,研究无乳链球菌对败血病患儿治疗有着重要意义。
Objectives To provide a reference for the treatment of sepsis in children by analyzing the types of pathogenic bacteria, drug resistance, serum indices, and virulence factors. Methods Subjects were 65 children with sepsis seen at this Hospital. Streptococcus agalactiae was isolated using blood cultures, DNA was extracted, and serum indices were determined, virulence genes were detected, and products were sequenced. Results The mean CRP level was 45.62±8.96 mg/L, the mean PCT level was 2.85±0.51 ng/ml, and the mean WBC count(×10~9) was 16.21±1.91×10~9, which were significantly higher than levels and counts in the control group(P<0.05). A total of 68 strains, 55 strains of Gram-positive bacteria and 13 strains of Gram-negative bacteria were isolated from samples from 65 patients. The main strains of Gram-positive bacteria were Streptococcus agalactiae, Staphylococcus epidermidis, S. aureus, and Enterococcus. The main strains of Gram-negative bacteria were Escherichia coli, Klebsiella pneumoniae, and Serratia marcescens. The main strain detected was Streptococcus agalactiae, and 22 strains were detected. Clinical isolates of the 55 Gram-positive strains had higher resistance to erythromycin(83.64%) and tetracycline(70.91%), lower resistance to ciprofloxacin(20.00%) and rifampicin(12.73%), and no resistance to vancomycin. S. agalactiae had high resistance to erythromycin(81.82%) and tetracycline(54.55%) but had no resistance to penicillin, cefazolin, ciprofloxacin, rifampicin, or vancomycin. The Gram-negative bacteria developed different degrees of resistance to amoxicillin(61.54%), amoxicillin + potassium clavulanate(38.46%), cefepime(38.46%), piperacillin(69.23%), piperacillin + tazobactam(30.77%), ciprofloxacin(23.08%), and imipenem(23.08%). Escherichia coli was resistant to amoxicillin(50.00%) and piperacillin(50.00%) but not to amoxicillin + clavulanic acid or piperacillin + tazobactam. Twenty-two strains of S. agalactiae were classified into 6 types: ST1(18.18% of strains), ST10(31.82%), ST12(13.64%), ST17(22.73%), ST19(13.64%), and ST27(4.55%.). The 22 strains of S. agalactiae were classified into 5 serotypes: Ia(13.64%of strains), Ib(45.45%,), Ⅱ(9.09%,), Ⅲ(13.64%), and Ⅴ(18.18%). The CylE, CFB, hylB, and LMB genes were detected in all 22 strains of S. agalactiae. The bac gene was detected at a rate of 45.45%. Type Ib strains all tested positive for the bac gene while other strains tested negative. The fbsA gene was detected at a rate of 45.45%. Conclusion Neonatal sepsis is severe neonatal condition. Bacteria have a certain degree of tolerance to commonly used drugs, so bacteria should be typed and subjected to drug resistance testing. Sepsis was mainly caused by S. agalactiae and its virulence factors were involved in the pathogenesis of sepsis, so research on S. agalactiae is crucial to the treatment of septicemia in children.
作者
雷延龄
陈源
杨晓会
张少丹
蒋秀芳
LEI Yan-ling;CHEN Yuan;YANG Xiao-hui;ZHANG Shao-dan;JIANG Xiu-fang(The Second Hospital of Hebei Medical University Shijiazhuang,Hebei,China 050000;The First Hospital of Hebei Medical University)
出处
《中国病原生物学杂志》
CSCD
北大核心
2020年第6期703-707,共5页
Journal of Pathogen Biology
关键词
败血症患儿
病原菌感染
无乳链球菌
耐药性
血清分型
毒力因子
children with sepsis
pathogen infection
Streptococcus agalactiae
drug resistance
serotyping
virulence factor
