Latouche S, Poirot J L, Bernard C, Roux P
Laboratoire de Parasitologie-Mycologie, CHU Saint-Antoine, Paris, France.
J Clin Microbiol. 1997 Jul;35(7):1687-90. doi: 10.1128/jcm.35.7.1687-1690.1997.
The objective of this study was to type, analyze, and compare Pneumocystis carinii hominis strains obtained from different samples during a given or recurrent episodes of P. carinii pneumonia (PCP) for epidemiologic purposes. We studied 36 bronchoalveolar lavage (BAL) or induced sputum (IS) samples from 16 human immunodeficiency virus-infected patients with one or several episodes of PCP. PCR amplification and direct sequencing were performed on the two internal transcribed spacers (ITS1 and ITS2) of P. carinii hominis rRNA genes by using DNA extracted from BAL or IS samples, and the sequences were compared to the mitochondrial large-subunit (mt LSU) gene sequence determined in a previous study in our laboratory. The studies of the mt LSU and ITS sequences showed that some patients (n = 10) were infected with the same strains of P. carinii hominis during a given episode of PCP. In one patient infected with strains with identical sequences in several episodes, the recurrence could have been due to reactivation of organisms not eliminated by treatment during the first episode or to de novo infection by an identical strain. In five patients infected with strains with different sequences in each episode, recurrence was due to de novo infection. Sequence analysis of these two P. carinii hominis gene regions showed that de novo infection can occur in AIDS patients with recurrent PCP.
本研究的目的是对卡氏肺孢子虫肺炎（PCP）特定发作期或复发期从不同样本中获取的人卡氏肺孢子虫菌株进行分型、分析和比较，以用于流行病学研究。我们研究了16例感染人类免疫缺陷病毒且患有一次或多次PCP发作的患者的36份支气管肺泡灌洗（BAL）或诱导痰（IS）样本。使用从BAL或IS样本中提取的DNA，对人卡氏肺孢子虫rRNA基因的两个内部转录间隔区（ITS1和ITS2）进行PCR扩增和直接测序，并将序列与我们实验室先前研究中确定的线粒体大亚基（mt LSU）基因序列进行比较。对mt LSU和ITS序列的研究表明，一些患者（n = 10）在PCP的特定发作期感染了相同的人卡氏肺孢子虫菌株。在一名在几次发作中感染了具有相同序列菌株的患者中，复发可能是由于首次发作时未被治疗清除的病原体重新激活，或者是由于相同菌株的再次感染。在五名每次发作感染不同序列菌株的患者中，复发是由于再次感染。对这两个人卡氏肺孢子虫基因区域的序列分析表明，再次感染PCP的艾滋病患者可能会发生再次感染。
