社区获得性肺炎患者痰中草绿色链球菌对肺炎链球菌影响的研究

发布时间：2018-09-16 19:24

【摘要】：目的：社区获得性肺炎（community-acquired pneumonia,CAP）在世界范围内是一种常见的感染性疾病，具有较高的发病率和病死率。目前国内外研究显示，肺炎链球菌（Streptococcus pneumoniae,SP）仍是CAP最主要的病原体。痰标本采集方便，是最常用的下呼吸道病原学检测标本，但痰培养肺炎链球菌阳性率并不高。本研究通过对住院的成人社区获得性肺炎患者行痰细菌培养，肺炎链球菌混入痰中培养，肺炎链球菌与痰中分离的草绿色链球菌(Streptococcus viridans,SV)混合后培养，探讨痰培养肺炎链球菌阳性率低的原因。方法：1．收集我院2011年7月-2012年3月住院的成人CAP患者，采集痰标本行细菌培养及鉴定，发热≥38.5℃行静脉血培养。 2．将肺炎链球菌与患者合格痰标本混匀后行半定量培养。实验组将5个浓度梯度的肺炎链球菌与15例CAP患者痰标本混匀，接种于血平板上行半定量培养，对照组用同等浓度的纯肺炎链球菌菌悬液接种于血平板上行半定量培养，比较两种培养结果肺炎链球菌生长是否有差异。 3．将肺炎链球菌与痰中分离的草绿色链球菌混合后行半定量培养：实验组将肺炎链球菌与痰中分离出的15株草绿色链球菌混匀后接种于血平板上行半定量培养，对照组用同等浓度的肺炎链球菌菌悬液与生理盐水混合后接种于血平板行半定量培养，比较两种培养结果肺炎链球菌生长是否有差异。结果:1．54/63例行痰细菌培养，阳性率20.37%（11/53），共分离出5种病原体，大肠埃希菌3.7%（1/54）、白色念珠菌9.26%（5/54）、肺炎克雷伯杆菌3.7%（2/54）、鲍曼不动杆菌杆菌3.7%（2/54），光滑假丝酵母菌1.85%（1/54），肺炎链球菌阳性率为0%（0/54）。 2．肺炎链球菌浓度10~3、10~4、10~5cfu/ml混痰培养，与混生理盐水对照组相比，肺炎链球菌生长数量明显减少（P＜0.05）；当肺炎链球菌浓度为10~2cfu/ml时，混痰后肺炎链球菌生长无明显减少（P=0.535）。 3．肺炎链球菌与A组草绿链球菌（SV浓度10~8cfu/ml）混合后倍比稀释培养结果：与纯肺炎链球菌菌悬液的对照组相比，草绿色链球菌浓度为10~7cfu/ml与肺炎链球菌浓度10~6cfu/ml、草绿色链球菌10~5cfu/ml与肺炎链球菌10~4cfu/ml混合培养后，肺炎链球菌生长数量明显减少（P＜0.05），，草绿色链球菌浓度10~6与肺炎链球菌浓度10~5混合培养后，肺炎链球菌生长明显减少，但差异无统计学意义（P=0.241）；肺炎链球菌与B组草绿链球菌（SV浓度10~7cfu/ml）混合后倍比稀释培养结果：草绿色链球（浓度为10~6、10~5、10~4、10~3、10~2）与同等浓度的肺炎链球菌混合培养后（10~6、10~5、10~4、10~3、10~2），与对照组相比肺炎链球菌生长数量无明显改变（P＞0.05）；肺炎链球菌与C组草绿链球菌（SV浓度10~6cfu/ml）混合倍比稀释培养结果：草绿色链球菌（浓度为10~5、10~4、10~3、10~2、10~1），分别与肺炎链球菌（浓度为10~6、10~5、10~4、10~3、10~2）混合培养后肺炎链球菌生长数量无明显改变（P＞0.05）。结论：本研究显示草绿色链球菌可能对肺炎链球菌的生长有抑制作用，这可能是导致社区获得性肺炎患者痰培养肺炎链球菌阳性率低的原因之一。
[Abstract]:Objective: Community-acquired pneumonia (CAP) is a common infectious disease with high morbidity and mortality in the world. At present, studies at home and abroad show that Streptococcus pneumoniae (SP) is still the main pathogen of CAP. In this study, the sputum culture of adult community-acquired pneumonia patients was studied by sputum bacterial culture, pneumococcus mixed with sputum culture, Pneumonia Streptococcus viridans (SV) isolated from sputum mixed with Streptococcus pneumoniae. The positive rate of Streptococcus is low.
Methods: 1. Collect the adult patients with CAP hospitalized in our hospital from July 2011 to March 2012, collect sputum samples for bacterial culture and identification, fever (> 38.5 C) venous blood culture.
2. Streptococcus pneumoniae were mixed with qualified sputum specimens and then semi-quantitatively cultured. Five concentration gradients of Streptococcus pneumoniae were mixed with 15 CAP sputum specimens in the experimental group and inoculated on the blood plate for semi-quantitatively cultured. The control group was inoculated with the same concentration of pure Streptococcus pneumoniae suspension on the blood plate for semi-quantitatively cultured. The results showed that there were differences in the growth of Streptococcus pneumoniae.
3. Mixing Streptococcus pneumoniae with Streptococcus viridis isolated from sputum for semi-quantitative culture: 15 strains of Streptococcus viridis isolated from sputum and Streptococcus pneumoniae were inoculated on the blood plate for semi-quantitative culture, while the control group was inoculated on the blood level with the same concentration of Streptococcus pneumoniae suspension mixed with physiological saline. Semi quantitative culture was used to compare the growth of Streptococcus pneumoniae in two cultures.
Results: 1.54/63 cases of sputum bacterial culture, the positive rate was 20.37% (11/53), a total of 5 pathogens were isolated, Escherichia coli 3.7% (1/54), Candida albicans 9.26% (5/54), Klebsiella pneumoniae 3.7% (2/54), Acinetobacter baumannii 3.7% (2/54), Candida smooth 1.85% (1/54), Streptococcus pneumoniae 0% (0/54).
2. The growth of Streptococcus pneumoniae in the mixed sputum culture with the concentration of 10~3,10~4,10~5 cfu/ml was significantly lower than that in the mixed saline control group (P < 0.05). When the concentration of Streptococcus pneumoniae was 10~2 cfu/ml, the growth of Streptococcus pneumoniae did not decrease significantly (P = 0.535).
3. Pneumococcus mixed with group A Streptococcus grass green (SV concentration 10-8 cfu/ml) dilution culture results: compared with the control group of pure Streptococcus pneumoniae suspension, the concentration of Streptococcus grass green is 10-7 cfu/ml and Streptococcus pneumoniae 10-6 cfu/ml, Streptococcus grass 10-5 cfu/ml and Streptococcus pneumoniae 10-4 cfu/ml mixed culture, Streptococcus pneumoniae pneumoniae pneumoniae pneumoniae Pneumoni The growth of Streptococcus pneumoniae decreased significantly (P After mixed culture of 10~6,10~5,10~4,10~3,10~2 with the same concentration of Streptococcus pneumoniae (10~6,10~5,10~4,10~3,10~2), the growth quantity of Streptococcus pneumoniae had no significant change compared with the control group (P > 0.05); the mixed dilution culture of Streptococcus pneumoniae and Streptococcus grass green (SV concentration 10~6 cfu/ml) showed that Streptococcus grass (concentration 10~6 cfu/ml) had no significant change. There was no significant change in the growth of S. pneumoniae after mixed culture with S. pneumoniae at concentrations of 10~6, 10~5, 10~4, 10~3, 10~2 (P > 0.05).
Conclusion:
This study suggests that Streptococcus viride may inhibit the growth of Streptococcus pneumoniae, which may be one of the reasons for the low positive rate of Streptococcus pneumoniae cultured in sputum from patients with community acquired pneumonia.
【学位授予单位】：大连医科大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R563.1

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