Pérez Giffoni Gabriel, García Gabarrot Gabriela, Alfonso Adriana, Pujadas Mónica, Camou Teresa
Ministerio de Salud Pública, Departamento de Laboratorios de Salud Pública, Montevideo, Uruguay.
Rev Panam Salud Publica. 2011 Dec;30(6):540-4. doi: 10.1590/s1020-49892011001200007.
The objective of this study was to characterize the phenotype and genotype of two isolates of rifampicin-resistant Neisseria meningitidis associated with two independent events involving transmission of severe meningococcal meningitis that occurred in September and October 2010 in Montevideo, Uruguay. The most recent 10 years of data from the national antimicrobial resistance surveillance system were reviewed to estimate the frequency of the particular meningococcal features that were characterized. Rifampicin resistance was studied using the epsilometer test. The serotype and serosubtype of the isolates were determined by ELISA, and the genotype was characterized using DNA digestion with Nhel and pulse field gel electrophoresis. The two isolates were identical: B:2a:P1.5. In the collection of 408 strains of N. meningitidis isolated in Uruguay in the past 10 years, the phenotype only appeared in two isolates, which were sensitive to rifampicin. The two isolates studied also shared a single pulse type, which was different from that of two other rifampicin-resistant isolates obtained in 2003 and 2007. Consequently, it was concluded that both cases of transmission were caused by a single rifampicin-resistant strain, which could have been an import from another country or else the result of a drift from serogroup C to B due to selective pressure exerted by vaccines administered to the population. It is essential to maintain and maximize surveillance. However, since this type of finding has been sporadic so far, unless a secondary case is identified, there is no justification for changing the antimicrobial drug currently being administered to contacts as prophylaxis.
本研究的目的是对两株耐利福平的脑膜炎奈瑟菌分离株的表型和基因型进行鉴定，这两株菌与2010年9月和10月在乌拉圭蒙得维的亚发生的两起涉及严重脑膜炎球菌性脑膜炎传播的独立事件相关。回顾了国家抗菌药物耐药性监测系统最近10年的数据，以估计所鉴定的特定脑膜炎球菌特征的频率。使用埃普利托霉素试验研究利福平耐药性。通过酶联免疫吸附测定法确定分离株的血清型和血清亚型，并使用Nhel酶切DNA和脉冲场凝胶电泳对基因型进行鉴定。这两株分离株相同：B:2a:P1.5。在过去10年于乌拉圭分离出的408株脑膜炎奈瑟菌中，该表型仅出现在两株对利福平敏感的分离株中。所研究的这两株分离株还共有一种单一脉冲型，这与2003年和2007年获得的另外两株耐利福平分离株不同。因此，得出的结论是，这两起传播病例均由单一耐利福平菌株引起，该菌株可能是从另一个国家传入，或者是由于对人群接种疫苗所施加的选择压力导致血清群C向B漂移的结果。维持并最大限度地加强监测至关重要。然而，由于迄今为止这类发现一直是零星的，除非发现二代病例，否则没有理由改变目前用于接触者预防给药的抗菌药物。
