Επιδημιολογική μελέτη της πολλαπλής φορείας της neisseria meningitidis. Ταυτοποίηση και τυποποίηση των υπεύθυνων για τη φορεία και τη μηνιγγιτιδοκοκκίκη νόσο στελεχών με μοριακές και συμβατικές τεχνικές: Κεσανόπουλος Κωνσταντίνος

Abstract

Meningococcal disease remains an important public health issue, due to the rapid onset of the disease, the high case fatality and the high proportion of surving patients with severe complications. The constant epidemiological surveillance of Neisseria meningitidis prevalence among sporadic cases, as well as among carriers, contributes significantly in the efficient monitoring of the disease. The aim of the present study was the development of a new methodology for the molecular identification and typing of N. meningitidis (crgA Real Time PCR, porA Single - Stranded conformation Polymorphism analysis, (SSCP - PCR ), Variable Number Tandem Repeat, VNTR - PCR). The designed molecular techniques were evaluated for the diagnosis of the meningococcal disease directly in clinical samples. In addition, they were applicated to the investigaton of phylogenetic relationship between N. meningitidis strains isolated from patients and carriers. Moreover, the developed techniques were used in an attempt to provide evidence for multiple meningococcal colonization of one carrier and to determine the frequence of this occurance in a study time period of 5 months. The high sensitivity and specificity of crgA Real Time PCR, as resulted from its evaluation, make it a method of choice for the rapid diagnosis of meningococcus directly in clinical samples. The porA SSCP PCR was successfully applied in molecular typing of meningococcal strains according to their serosubtype. Furthermore, the application of the technique in culture negative clinical samples, isolated from patients during a local outbreak, allowed the phylogenetic correlation of these cases overcoming the lack of meningococcal strains. According to the obtained results during the study for the investigation of the presence of genetic correlation, between patients and carriers strains from 2 local meningococcal outbreaks, VNTR PCR appears to be a highly discriminatory method, which can contribute significantly in the epidemiological surveillance of local meningococcal outbreak. The carriage of meningococcus was studied in 202 young adults, 19-25 years old, studying either at the Medical School of the University of Ioannina or at the Technological Institution of Serres, for a time period of 5 months.