First Report of Capsule Replacement among Electrophoretic Type 37 Neisseria meningitidis Strains in Italy

Abstract

This report describes the C-to-B capsular switching in four Neisseria meningitidis strains belonging to the electrophoretic type 37 (ET-37) complex. In particular, one strain belonged to the new sequence type 1860, which was first detected in the year 2000 in Italy and is now frequently isolated. The presence of switched serogroup B strains deserves special attention if they prove as able to spread as their serogroup C progenitors belonging to the hypervirulent ET-37 complex.

Clonal Distribution of Invasive Neisseria meningitidis Serogroup C Strains Circulating from 1976 to 2005 in Greater São Paulo, Brazil

“…Capsular switching may occur naturally, and immunization with vaccines that target serogroup capsules could potentially favor the emergence of serogroup B ST-11 complex strains as reported in Canada and Spain, where serogroup B ST-11 complex strains have emerged since the introduction of serogroup C conjugate vaccines (1,24,33). In GSP, only two serogroup B 2a:P1.5,2 ET-5 complex strains were found, 16 and 20 years after the AC vaccination campaign, when similar prevalence of MD caused by serogroups B and C was reported (26).…”

Multilocus Sequence Typing of Neisseria meningitidis Directly from Clinical Samples and Application of the Method to the Investigation of Meningococcal Disease Case Clusters

“…Although genogroup identification of meningococci from clinical specimens by nucleic acid amplification (35) partially rectifies this problem, full strain characterization for meningococci remains important due to the phenomenon of capsular switching, whereby meningococci can express alternative capsular serogroups due to recombination in the cps operon (2,21,31,33,37,40). It is important that any method applied to the strain characterization of meningococi directly from clinical specimens be able to provide data that can identify organisms belonging to hypervirulent lineages, such as the ST-11/ET-37 complex, by adapting it for use directly on clinical specimens.…”

“…Meningococcal infection is a major public health problem in the United Kingdom (20,28,30) and elsewhere (1,2,9,21,31,44), with a wide spectrum of disease, from benign meningococcemia and meningococcal meningitis to rapidly fulminant fatal septicemia. During the 1990s, the discrepancy between the numbers of laboratory-confirmed cases of meningococcal infection and the numbers of cases reported to the Office of National Statistics for England and Wales (28) widened progressively.…”

Detección de cepas de Neisseria meningitidis resistentes a rifampicina en el Uruguay

“…Los aislamientos del mismo fenotipo analizados por MLST fueron asignados al complejo ET-37 o al conglomerado A4 (14). En Italia, en 2000, se notificó un brote causado por una cepa probablemente originada en la Argentina, C:2b:P1.5 con un ST1860 no descrito hasta ese momento, que era una variante en un único alelo del ST11/complejo ET-37 (15). Estos resultados sugieren que tanto los aislamientos resistentes a rifampicina de 2010 como la cepa prototipo del clon Paysandú corresponderían al complejo ET-37.…”