Identification of high immunoreactive proteins fromStreptococcus agalactiaeisolates recognized by human serum antibodies

Abstract

The aim of the studies was to identify immunogenic proteins of Streptococcus agalactiae (group B streptococcus; GBS) isolates. Investigation of the immunoreactivity with human sera allowed us to determine major immunogenic proteins which might be potential candidates for the development of vaccine. For the study, we have selected 60 genetically different, well-characterized GBS clinical isolates. The proteins immunoreactivity with 24 human sera from patients with GBS infections, carriers, and control group without GBS was detected by SDS-PAGE and Western blotting. As a result, some major immunogenic proteins were identified, of which four proteins with molecular masses of about 45 to 50 kDa, which exhibited the highest immunoreactivity features, were analyzed by LC-MS/MS. The proteins were identified by comparative analysis of peptides masses using MASCOT and statistical analysis. The results showed known molecules such as enolase (47.4 kDa), aldehyde dehydrogenase (50.6 kDa), and ones not previously described such as trigger factor (47 kDa) and elongation factor Tu (44 kDa). The preliminary results indicated that some GBS proteins that elicit protective immunity hold promise not only as components in a vaccine as antigens but also as carriers or adjuvants in polysaccharide conjugate vaccines, but more studies are needed.

Epitopes of Immunoreactive Proteins of Streptococcus Agalactiae: Enolase, Inosine 5′-Monophosphate Dehydrogenase and Molecular Chaperone GroEL

“…In our previous study at least four immunoreactive proteins, including enolase, were identified in a pool of sixty genetically different GBS strains isolated from various infection types (Brzychczy-Wloch et al, 2013 ). In this paper, we extended the number of bacterial samples tested ( n = 180) and included umbilical cord serum ( n = 34).…”

“…S. agalactiae isolates ( n = 180) came from the study group of pregnant women ( n = 20), from the patients with urinary tract infections (UTI) ( n = 100) and strains from the pregnant, non-pregnant patients, and newborns, with different clinical status (infection and carrier), isolated from various material, such as blood, vagina and anus swabs, newborn ear swab and, urine ( n = 60) collected within the framework of two projects financed by the Polish Ministry of Research and Higher Education and no. 3PO5E08425 and NN401042337 and described in details in our previous paper (Brzychczy-Wloch et al, 2013 ). The isolates tested represented various serotypes (Ia, Ib, II-V), different genes coding surface of the Alpha-like proteins ( bca, alp2, alp3, epsilon, rib ), different macrolide resistance phenotypes (cMLSB, iMLSB, M), various sequence types (ST) and came from different regions of Poland.…”

“…Identification of the bacterial species was performed by PCR with species-specific primers (Ke et al, 2000 ). Molecular characterization of the tested GBS strains was based on the methodology described in our previous work (Brzychczy-Wloch et al, 2013 ). All strains were stored at −70°C.…”

“…In our previous research, four immunogenic proteins, including: enolase (47.4 kDa), aldehyde dehydrogenase (50.6 kDa) and, firstly described as being immunogenic in GBS, the trigger factor (47 kDa) and elongation factor Tu (44 kDa) have been described (Brzychczy-Wloch et al, 2013 ). In the present paper, we identified two more immunogenic proteins: inosine 5′-monophosphate dehydrogenase (IMPDH) (53 kDa) and the molecular chaperone GroEL (57 kDa).…”

Prevención de la infección por Streptococcus del grupo B en gestantes

“…Éstas últimas fueron descritas en un estudio en el que dentro de 898 aislamientos de SGB, el 70% compartía al menos una isla de pilis, PI-142. También se han estudiado proteínas inmunogénicas, tales como la enolasa, aldehído deshidrogenasa y factor de elongación Tu (46).…”