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Experimental Human Pneumococcal Carriage
07:47

Experimental Human Pneumococcal Carriage

Published on: February 15, 2013

Association between asymptomatic carriage and sporadic (endemic) meningococcal disease in an open community

M E Verdú1, P Coll, J A Vázquez

  • 1Servei de Microbiologia, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.

Epidemiology and Infection
|November 6, 2001
PubMed

Insights

Neisseria meningitidis shows low transmission and weak clonal structure in a Spanish community. Most patient isolates belonged to hyper-virulent lineages, unlike most asymptomatic carriers.

Area of Science:

  • Microbiology
  • Epidemiology
  • Genetics

Background:

  • Neisseria meningitidis is a significant human pathogen.
  • Understanding meningococcal population structure is crucial for public health.
  • Previous studies suggest clonal expansion in some meningococcal outbreaks.

Purpose of the Study:

  • To analyze the population structure of Neisseria meningitidis during an endemic period in a Spanish community.
  • To compare phenotypic and molecular typing methods for characterizing meningococcal strains.
  • To assess the transmission dynamics and clonal behavior of Neisseria meningitidis.

Main Methods:

  • Analysis of 30 patient isolates and 191 throat carriage isolates from a community of 46,000 inhabitants.
  • Utilized multilocus enzyme electrophoresis (MEE) and pulsed-field gel electrophoresis (PFGE) for molecular typing.
  • Employed phenotypic techniques to assess strain characteristics.

Main Results:

  • Hyper-virulent lineages (ET-5, ET-37 complexes, cluster A4) predominated in patient isolates (almost all).
  • Carrier isolates showed lower assignment to hyper-virulent clones (20% MEE, 15% PFGE, 4% combined).
  • Discrepancies between MEE and PFGE in carrier isolates suggest recombination events, indicating a weak clonal structure.

Conclusions:

  • Neisseria meningitidis exhibits low transmission rates within the studied community.
  • The bacterium displays a weak clonal structure, with significant recombination impacting strain associations.
  • Distinct population structures were observed between patients and asymptomatic carriers.

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