脑膜炎球菌(脑膜炎奈瑟氏菌)血清群B(MenB)菌株抗原是多种多样的,并且可以使用人血清杀菌抗体(hSBA)测定法评估有限数量的菌株。遗传脑膜炎球菌抗原分型系统(gMATS)的开发是为了预测4CMenB疫苗覆盖大量分离株的可能性,其中包括抗原奈瑟氏菌粘附素A(NadA),奈瑟氏菌肝素结合抗原(NHBA),H因子结合蛋白(fHbp),和PorinA(PorA)。在这项研究中,我们通过全基因组分析对阿根廷国家实验室网络从2010年至2014年收集的284个侵袭性MenB分离株进行了表征(每年52-61个分离株).通过gMATS对所有分离株进行评估,并通过hSBA测定对74个随机选择的分离株进行评估,代表整个小组。四种最常见的克隆复合物(CC),占分离株的81.3%,是CC-865(75个分离株,26.4%),CC-32(59,20.8%),CC-35(59,20.8%),和CC-41/44(38,13.4%)。疫苗抗原基因分型显示多样性。最普遍的变体/肽是fHbp变体2,NHBA肽24、21和2,以及PorA可变区2谱16-36和14。nadA基因存在于66个(23.2%)分离株中。通过hSBA测定估计的菌株覆盖率显示78.4%的分离株被汇集的青少年血清杀死,51.4%和64.9%(基于两个不同的阈值)被合并的婴儿血清杀死。gMATS估计覆盖率(61.3%;预测区间:55.5%,66.7%)与婴儿hSBA测定结果一致。需要持续的基因组监测来评估阿根廷主要MenBCC的持久性。
侵袭性脑膜炎球菌病最常见的临床表现包括脑膜炎和败血症,这可能是致命的,许多幸存者遭受长期严重的后遗症。大多数侵袭性脑膜炎球菌病病例是由六种脑膜炎球菌血清群(类型)引起的,包括血清群B。尽管有针对脑膜炎球菌血清群B感染的疫苗,这些疫苗靶向高度多样化的抗原。因此,疫苗接种的有效性可能因国家而异,因为在特定地区传播的脑膜炎球菌血清群B菌株携带不同形式的靶疫苗抗原.这意味着重要的是测试从特定群体分离的血清群B菌株以估计疫苗可能有效对抗的菌株的百分比(称为“疫苗菌株覆盖率”)。遗传脑膜炎球菌抗原分型系统(gMATS)的开发是为了预测四组分脑膜炎球菌血清群B疫苗的菌株覆盖率,4CMenB,针对大量血清群B菌株。在这项研究中,我们分析了2010年至2014年间在阿根廷收集的284株侵袭性脑膜炎球菌血清群B分离株.遗传分析表明,分离株的疫苗抗原多种多样,在其他国家的分离株中没有发现某些遗传特征。然而,gMATS估计的疫苗株覆盖率与世界其他地区报道的一致,并且与通过另一种方法获得的子集的菌株覆盖率结果一致,人血清杀菌抗体(hSBA)测定。这些结果强调需要继续监测循环细菌菌株以评估脑膜炎球菌血清群B疫苗的估计菌株覆盖率。
Meningococcal (Neisseria meningitidis) serogroup B (MenB) strain antigens are diverse and a limited number of strains can be evaluated using the human serum bactericidal antibody (hSBA) assay. The genetic Meningococcal Antigen Typing System (gMATS) was developed to predict the likelihood of coverage for large numbers of isolates by the 4CMenB vaccine, which includes antigens Neisseria adhesin A (NadA), Neisserial Heparin-Binding Antigen (NHBA), factor H-binding protein (fHbp), and Porin A (PorA). In this study, we characterized by whole-genome analyses 284 invasive MenB isolates collected from 2010 to 2014 by the Argentinian National Laboratories Network (52-61 isolates per year). Strain coverage was estimated by gMATS on all isolates and by hSBA assay on 74 randomly selected isolates, representative of the whole panel. The four most common clonal complexes (CCs), accounting for 81.3% of isolates, were CC-865 (75 isolates, 26.4%), CC-32 (59, 20.8%), CC-35 (59, 20.8%), and CC-41/44 (38, 13.4%). Vaccine antigen genotyping showed diversity. The most prevalent variants/peptides were fHbp variant 2, NHBA peptides 24, 21, and 2, and PorA variable region 2 profiles 16-36 and 14. The nadA gene was present in 66 (23.2%) isolates. Estimated strain coverage by hSBA assay showed 78.4% of isolates were killed by pooled adolescent sera, and 51.4% and 64.9% (based on two different thresholds) were killed by pooled infant sera. Estimated coverage by gMATS (61.3%; prediction interval: 55.5%, 66.7%) was consistent with the infant hSBA assay results. Continued genomic surveillance is needed to evaluate the persistence of major MenB CCs in Argentina.
The most common clinical manifestations of invasive meningococcal disease include meningitis and septicemia, which can be deadly, and many survivors suffer long-term serious after-effects. Most cases of invasive meningococcal disease are caused by six meningococcal serogroups (types), including serogroup B. Although vaccines are available against meningococcal serogroup B infection, these vaccines target antigens that are highly diverse. Consequently, the effectiveness of vaccination may vary from country to country because the meningococcal serogroup B strains circulating in particular regions carry different forms of the target vaccine antigens. This means it is important to test serogroup B strains isolated from specific populations to estimate the percentage of strains that a vaccine is likely to be effective against (known as ‘vaccine strain coverage’). The genetic Meningococcal Antigen Typing System (gMATS) was developed to predict strain coverage by the four-component meningococcal serogroup B vaccine, 4CMenB, against large numbers of serogroup B strains. In this study, we analyzed 284 invasive meningococcal serogroup B isolates collected between 2010 and 2014 in Argentina. Genetic analyses showed that the vaccine antigens of the isolates were diverse and some genetic characteristics had not been found in isolates from other countries. However, vaccine strain coverage estimated by gMATS was consistent with that reported in other parts of the world and with strain coverage results obtained for a subset via another method, the human serum bactericidal antibody (hSBA) assay. These results highlight the need for continued monitoring of circulating bacterial strains to assess the estimated strain coverage of meningococcal serogroup B vaccines.