成人重症肺炎的肺炎链球菌血清型及耐药性分析

Analysis of serotype and drug resistance of Streptococcus pneumoniae in adults with severe pneumonia

目的探讨ICU内重症肺炎患者痰及支气管灌洗液中肺炎链球菌的常见血清型及耐药性。方法 2019年8月-11月收集本院ICU内机械通气重症肺炎患者的痰液和支气管镜冲洗液,分离培养肺炎链球菌。荚膜肿胀试验确定肺炎链球菌的血清型;纸片扩散法和E-test法检测肺炎链球菌对抗生素的敏感性;PCR检测mef A和erm B基因。结果 164份样本中分离出104株肺炎链球菌,主要血清型为19F(26株,25.0%)、6A(22株,21.2%)。肺炎链球菌对青霉素和头孢菌素的敏感率分别为83.7%、77.9%~85.6%,对亚胺培南、万古霉素和利奈唑胺敏感,分别为93.3%、90.4%和94.2%,对青霉素的耐药率为9.6%,对红霉素和阿奇霉素的耐药率分别高达90.4%、84.4%。mef A和erm B耐药基因携带率分别为65.4%和87.5%。结论 ICU内社区获得性重症肺炎患者肺炎链球菌毒力强,对大环内酯类药物耐药率高。抗性基因主要是erm B。因此,大环内酯类不适合经验性治疗重症肺炎。临床医生应根据药敏试验和患者病情合理使用抗生素。

Objective To investigate the serotype and drug resistance of Streptococcus pneumoniae in clinical samples of adult patients with severe pneumonia in ICU ward. Methods Samples of sputum,bronchofiberscope washing fluid and cerebrospinal fluid were collected from patients with severe pneumonia who received mechanical ventilation in ICU ward from August 2019 to November 2019. Streptococcus pneumoniae were cultured and isolated. The serotype of Streptococcus pneumoniae was identified by capsule swelling test. The sensitivity of Streptococcus pneumoniae was detected by E-test method and disk diffusion method.mef A and erm B resistance genes of macrocyclic lipids were detected by PCR. Results A total of 164 samples were collected during the study,which mainly were 19 F( 26 strains,25. 0%),6 A( 22 strains,21. 2%). The sensitivity rates of S. pneumoniae to penicillin and cephalosporin were 83. 7% and 77. 9%-85. 6%,respectively. The sensitivity to imipenem,vancomycin and linezolid was 93. 3%,90. 4% and 94. 2%,respectively. The drug resistance rate of penicillin was 9. 6%,and that of erythromycin and azithromycin were 90. 4% and 84. 4% respectively. The rates of mef A and erm B were 65. 4% and 87. 5%,respectively. Conclusion Streptococcus pneumoniae is highly virulent and resistant to macrolides in patients with severe pneumonia in ICU ward,and the resistance gene is mainly erm B,so macrolides are not suitable for patients with severe pneumonia.Clinicians should use antibiotics reasonably according to drug sensitivity and patient’s condition.