Department of Microbiology, Immunology, Parasitology and Pathology, Federal University of Goiás, Goiânia, Brazil.
Adolfo Lutz Institute, São Paulo, Brazil.
J Med Microbiol. 2012 May;61(Pt 5):686-692. doi: 10.1099/jmm.0.040790-0. Epub 2012 Jan 27.
A child's death due to pneumococcal meningitis after contracting the disease in an after-school programme prompted an investigation to assess nasopharyngeal (NP) carriage among her contacts. The serotype of the meningitis case isolate was determined, together with the serotypes of the NP specimens of contacts, comprising the case patient's brother, the case patient's after-school programme contacts and the brother's day-care centre (DCC) contacts. NP swabs from 155 children and 69 adults were obtained. Real-time PCR and conventional multiplex PCR (CM-PCR) assays were used to detect pneumococcal carriage and determine serotypes. Broth-enriched culture of NP specimens followed by pneumococcal isolation and Quellung-based serotyping were also performed. DNA extracts prepared from cerebrospinal fluid of the index case and from the NP strain isolated from the brother and from one attendee of the brother's DCC were subjected to genotyping. Pneumococcal carriage assessed by real-time PCR and culture was 49.6 and 36.6%, respectively (P<0.05). Twenty-three serotypes were detected using CM-PCR, with serotypes 6A/6B, 14, 19F, 6C/6D, 22F/22A, 23F and 11A/11D being the most frequent. All eight serotype 22F/22A NP specimens recovered were from children attending the brother's DCC. The meningitis case isolate and the NP carriage isolate from the patient's brother were both serotype 22F and shared the same new multilocus sequence type (ST6403) with the attendee of the brother's DCC. CM-PCR proved to be useful for assessing carriage serotype distribution in a setting of high-risk pneumococcal transmission. The causal serotype appeared to be linked to the brother of the case patient and attendees of his DCC.
一名儿童在课后活动中感染肺炎球菌后死于脑膜炎，促使开展调查以评估其接触者的鼻咽（NP）携带情况。对脑膜炎病例分离株的血清型进行了确定，并对接触者的 NP 标本的血清型进行了确定，接触者包括病例患者的兄弟、病例患者的课后活动接触者和兄弟的日托中心（DCC）接触者。共采集了 155 名儿童和 69 名成人的 NP 拭子。采用实时 PCR 和常规多重 PCR（CM-PCR）检测方法检测肺炎球菌携带情况并确定血清型。还对 NP 标本进行肉汤富集培养，然后进行肺炎球菌分离和基于 Quellung 的血清分型。从索引病例的脑脊液和从兄弟以及兄弟的 DCC 的一名参与者中分离出的 NP 株制备 DNA 提取物，并对其进行基因分型。实时 PCR 和培养法评估的肺炎球菌携带率分别为 49.6%和 36.6%（P<0.05）。使用 CM-PCR 检测到 23 种血清型，其中血清型 6A/6B、14、19F、6C/6D、22F/22A、23F 和 11A/11D 最为常见。从参加兄弟 DCC 的儿童中分离出的 8 个血清型 22F/22A NP 标本均为该型。脑膜炎病例分离株和患者兄弟的 NP 携带分离株均为血清型 22F，与兄弟 DCC 的参与者共享相同的新多位点序列型（ST6403）。CM-PCR 被证明可用于评估高风险肺炎球菌传播环境中的携带血清型分布。致病血清型似乎与病例患者的兄弟及其 DCC 的参与者有关。
