Dados do Trabalho

Título

Two new anti-Neisseria meningitidis monoclonal antibodies used for immunohistochemistry diagnostic in Adolfo Lutz Institute recognized most of 2023 isolates

Introdução

The bacterial meningitis are a public health problem due to the high morbidity and mortality. Effective strategies are needed to confirm the etiologic agent during laboratory diagnose.

Objetivo (s)

Here, we investigated if two new monoclonal antibodies (MAbs) used for Neisseria meningitidis detection in the Immunohistochemistry (IHC) Laboratory (Pathology Center, Adolfo Lutz Institute) would react with N. meningitidis strains isolated during 2023.

Material e Métodos

The murine MAbs F19A and 9B3 were developed in the Monoclonal Antibodies Laboratory (Immunology Center, Adolfo Lutz Institute) using the hybridoma technology, and their use for IHC was standardized before (CTC 17E/2013 and CAAE 22581214.9.0000.0059).  Here, inactivated suspensions of 118 strains of N. meningitidis (46 MenB, 49 MenC, 11 MenW and 10 MenY) (from Bacteriology Center, Adolfo Lutz Institute) were dotted in nitrocellulose membranes (Whatman®), MAbs were incubated overnight at 4ºC, diluted at 1/5 (F19A) or 1/50 (9B3), based on titration curves assessed during MAbs characterization. The reaction was revealed using anti-mouse IgG-γ plus anti-mouse IgM-µ (Kirkegaard & Perry Laboratories) conjugated with horseradish-peroxidase and 4-chloro-1-naphthol (Sigma) substrate. Colored dots were considered positive.

Resultados e Conclusão

The F19A MAb recognized 89% of MenB strains, 89% of MenC, 100% of MenW and 83% of MenY; the MAb 9B3 reacted with 80% of MenB strains, 91% of MenC, 90% of MenW and 83% of MenY. The serotypes 4,7, common of MenB and 23, usually of MenC, were present in the majority of strains studied. F19A reacted with 90% of strains presenting serotype 4,7 and 87% presenting serotype 23, while 9B3 reacted with 81% and 90%, respectively. An interesting feature of F19A and 9B3 MAbs is that both recognized strains presenting non-typable (nt) serotypes and/or subtypes, meaning that such strains were not recognized by the current MAbs’ panel. The strains were characterized with MAbs used for typing different serotypes and subtypes of N. meningitidis. The new monoclonal antibodies are cross-reactive, so they recognize epitopes present in different serogroups, serotypes and subtypes. Dot-blot is a cost-effective technique to characterize bacterial strains. Using MAbs that cross-react with several N. meningitidis strains is important to ensure that the diagnostic will identify different strains. In that way, MAbs are reliable tools to support epidemiologic surveillance.

Palavras Chave

Monoclonal antibodies; Neisseria meningitidis; Cross reaction