Molecular Epidemiological Analysis of the Changing Nature of a Meningococcal Outbreak following a Vaccination Campaign.
Shlush LI, Behar DM, Zelazny A, Keller N, Lupski JR, Beaudet AL, Bercovich D.
Department of Internal Medicine, Rambam Medical Center, and Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa. National Center for Meningococci, Haim Sheba Medical Center, Tel-Hashomer. Department of Molecular Genetics, MIGAL, Kiryat Shmona, Israel. Department of Human Molecular Genetics, Baylor College of Medicine, Houston, Texas.
A serogroup C meningococcal outbreak that occurred in an Israeli Arab village led to a massive vaccination campaign. During the subsequent 18 months, new cases of type B Neisseria meningitidis infection were revealed. To investigate the influence of vaccination on bacteriological epidemiology, bacteria were isolated from individuals at the outbreak location, patients with several additional other sporadic cases, and patients involoved in another outbreak. Haploid bacterial genomic DNA was mixed with a consensus PCR product to form a heteroduplex state that enabled multilocus sequence typing (MLST) to be combined with denaturing high-performance liquid chromatography (DHPLC) for a novel high-throughput molecular typing method called MLST-DHPLC. A 100% correlation was found to exist between the sequencing by MLST alone and the MLST-DHPLC method. Independent molecular typing by repetitive extragenic palindromic PCR discriminated the neisserial clones as well as the MLST-DHPLC method did. The occurrence of type B N. meningitidis in the postvaccination period might be attributed to the selection pressure applied to the bacteria by vaccination, suggesting a possible unwarranted outcome of vaccination with the quadrivalent vaccine for control of a serogroup C meningococcal outbreak. This is the first time that DHPLC has been applied to the genotyping of bacteria, and it proved to be more efficient than MLST alone.
PMID: 12354847 [PubMed - as supplied by publisher]