Gasparini Roberto, Comanducci Maurizio, Amicizia Daniela, Ansaldi Filippo, Canepa Paola, Orsi Andrea, Icardi Giancarlo, Rizzitelli Emanuela, De Angelis Gabriella, Bambini Stefania, Moschioni Monica, Comandi Sara, Simmini Isabella, Boccadifuoco Giueseppe, Brunelli Brunella, Giuliani Marzia Monica, Pizza Mariagrazia, Panatto Donatella
Department of Health Sciences, University of Genoa, Genoa, Italy
Novartis Vaccines and Diagnostics, Siena, Italy.
J Clin Microbiol. 2014 Jun;52(6):1901-10. doi: 10.1128/JCM.03584-13. Epub 2014 Mar 19.
Neisseria meningitidis is an obligate human commensal that commonly colonizes the oropharyngeal mucosa. Carriage is age dependent and very common in young adults. The relationships between carriage and invasive disease are not completely understood. In this work, we performed a longitudinal carrier study in adolescents and young adults (173 subjects). Overall, 32 subjects (18.5%) had results that were positive for meningococcal carriage in at least one visit (average monthly carriage rate, 12.1%). Only five subjects tested positive at all four visits. All meningococcal isolates were characterized by molecular and serological techniques. Multilocus sequence typing, PorA typing, and sequencing of the 4CMenB vaccine antigens were used to assess strain diversity. The majority of positive subjects were colonized by capsule null (34.4%) and capsular group B strains (28.1%), accounting for 23.5% and 29.4% of the total number of isolates, respectively. The fHbp and nhba genes were present in all isolates, while the nadA gene was present in 5% of the isolates. The genetic variability of the 4CMenB vaccine antigens in this collection was relatively high compared with that of other disease-causing strain panels. Indications about the persistence of the carriage state were limited to the time span of the study. All strains isolated from the same subject were identical or cumulated minor changes over time. The expression levels and antigenicities of the 4CMenB vaccine antigens in each strain were analyzed by the meningococcal antigen typing system (MATS), which revealed that expression can change over time in the same individual. Future analysis of antigen variability and expression in carrier strains after the introduction of the MenB vaccine will allow for a definition of its impact on nasopharyngeal/oropharyngeal carriage.
脑膜炎奈瑟菌是一种专性寄生于人类的微生物，通常定殖于口咽黏膜。携带情况与年龄相关，在年轻人中非常普遍。携带与侵袭性疾病之间的关系尚未完全明确。在本研究中，我们对青少年和年轻人（173名受试者）进行了一项纵向携带者研究。总体而言，32名受试者（18.5%）在至少一次访视中脑膜炎球菌携带检测结果呈阳性（平均每月携带率为12.1%）。只有5名受试者在所有4次访视中检测均呈阳性。所有脑膜炎球菌分离株均采用分子和血清学技术进行鉴定。使用多位点序列分型、PorA分型以及4CMenB疫苗抗原测序来评估菌株多样性。大多数阳性受试者被无荚膜菌株（34.4%）和B群荚膜菌株（28.1%）定殖，分别占分离株总数的23.5%和29.4%。所有分离株中均存在fHbp和nhba基因，而nadA基因仅在5%的分离株中存在。与其他致病菌株组相比，该样本中4CMenB疫苗抗原的遗传变异性相对较高。关于携带状态持续时间的信息仅限于研究时间段。从同一受试者分离出的所有菌株在一段时间内要么完全相同，要么累积了微小变化。通过脑膜炎球菌抗原分型系统（MATS）分析了各菌株中4CMenB疫苗抗原的表达水平和抗原性，结果显示同一受试者体内的表达水平可能随时间变化。在引入MenB疫苗后，对携带者菌株中抗原变异性和表达情况的进一步分析将有助于明确其对鼻咽/口咽携带的影响。
