Comparison of Phenotypic and Genotypic Approaches to Capsule Typing of Neisseria meningitidis by Use of Invasive and Carriage Isolate Collections

February 21, 2017 at 3:29 pm

Journal of Clinical Microbiology January 2016 V.54 N.1 P.25-34

Epidemiology

Hal Jones, Naglaa Mohamed, Eduardo Rojas, Lubomira Andrew, Johanna Hoyos, Julio C. Hawkins, Lisa K. McNeil, Qin Jiang, Leonard W. Mayer, Xin Wang, Rodica Gilca, Philippe De Wals, Louise Pedneault, Joseph Eiden, Kathrin U. Jansen, and Annaliesa S. Anderson

aPfizer Vaccine Research and Development, Pearl River, New York, USA

bMeningitis and Vaccine Preventable Diseases Branch, Division of Bacterial Diseases, National Center for Immunizations and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA

cInstitut National de Santé Publique du Québec, Quebec City, Canada

dLaval University, Quebec City, Canada

eCHU de Québec, Quebec City, Canada

aPfizer Vaccine Research and Development, Pearl River, New York, USA

bMeningitis and Vaccine Preventable Diseases Branch, Division of Bacterial Diseases, National Center for Immunizations and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA

cInstitut National de Santé Publique du Québec, Quebec City, Canada

dLaval University, Quebec City, Canada

eCHU de Québec, Quebec City, Canada

Neisseria meningitidis serogroup B (MnB) is a leading cause of bacterial meningitis; however, MnB is most commonly associated with asymptomatic carriage in the nasopharyngeal cavity, as opposed to the disease state.

Two vaccines are now licensed for the prevention of MnB disease; a possible additional benefit of these vaccines could be to protect against disease indirectly by disrupting nasopharyngeal carriage (e.g., herd protection).

To investigate this possibility, accurate diagnostic approaches to characterize MnB carriage isolates are required. In contrast to invasive meningococcal disease (IMD) isolates, which can be readily serogrouped, carriage isolates often lack capsule expression, making standard phenotypic assays unsuitable for strain characterization.

Several antibody-based methods were evaluated for their abilities to serogroup isolates and were compared with two genotyping methods (real-time PCR [rt-PCR] and whole-genome sequencing [WGS]) to identify which approach would most accurately ascertain the polysaccharide groups associated with carriage isolates.

WGS and rt-PCR were in agreement for 99% of IMD isolates, including those with coding sequences for MnB, MnC, MnW, and MnY, and the phenotypic methods correctly identified serogroups for 69 to 98% of IMD isolates.

In contrast, only 47% of carriage isolates were groupable by genotypic methods, due to mutations within the capsule operon; of the isolates identified by genotypic methods, ≤43% were serogroupable with any of the phenotypic methods tested.

These observations highlight the difficulties in the serogrouping and capsular genogrouping of meningococcal carriage isolates. Based on our findings, WGS is the most suitable approach for the characterization of meningococcal carriage isolates.

PDF

http://jcm.asm.org/content/54/1/25.full.pdf

Advertisements

Entry filed under: Antimicrobianos, Bacterias, Bacteriemias, Biología Molecular, Epidemiología, Inmunizaciones, Metodos diagnosticos, Update.

Unveiling New Aspects of Meningococcal Carriage and Disease Prevention Untargeted Metabolomics To Ascertain Antibiotic Modes of Action


Calendar

February 2017
M T W T F S S
« Jan   Mar »
 12345
6789101112
13141516171819
20212223242526
2728  

Most Recent Posts


%d bloggers like this: