A MALDI-TOF MS-based approach to improve group B Streptococcus screening among pregnant people in Brazil

Introduction: Group B Streptococcus (GBS) is a leading agent of sepsis and meningitis in neonates. Prevention is made by screening pregnant women at 36-37 gestational weeks and applying intrapartum antibiotic prophylaxis (IAP). However, GBS colonization in pregnant women can be transient or intermit...

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Main Authors: Dr Tatiana Pinto, Debora Nery, Dr Laura Oliveira, Dr Natalia Costa, Prof Sergio Fracalanzza, Dr Ana Caroline Botelho, Prof Lucia Teixeira, Dr Penelope Marinho
Format: Article
Language:English
Published: Elsevier 2025-03-01
Series:International Journal of Infectious Diseases
Online Access:http://www.sciencedirect.com/science/article/pii/S1201971224005459
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author Dr Tatiana Pinto
Debora Nery
Dr Laura Oliveira
Dr Natalia Costa
Prof Sergio Fracalanzza
Dr Ana Caroline Botelho
Prof Lucia Teixeira
Dr Penelope Marinho
author_facet Dr Tatiana Pinto
Debora Nery
Dr Laura Oliveira
Dr Natalia Costa
Prof Sergio Fracalanzza
Dr Ana Caroline Botelho
Prof Lucia Teixeira
Dr Penelope Marinho
author_sort Dr Tatiana Pinto
collection DOAJ
description Introduction: Group B Streptococcus (GBS) is a leading agent of sepsis and meningitis in neonates. Prevention is made by screening pregnant women at 36-37 gestational weeks and applying intrapartum antibiotic prophylaxis (IAP). However, GBS colonization in pregnant women can be transient or intermittent. GBS-negative women at 36-37 gestational week may be GBS-positive at the moment of labor, and vice-versa. Culture-based techniques have a long turnaround-time (TAT), and the development of a cost-effective, reliable and fast screening method that could be applied just before labor can aid to antimicrobial stewardship. Here we propose a MALDI-TOF-based protocol for GBS detection directly in pre-enriched clinical samples. Methods: Anovaginal samples of 612 women attending a maternity in Rio de Janeiro, Brazil, between July 2019 and May 2021, were processed as follows. After pre-enriching clinical samples for 18h at 36°C, they were subcultured onto blood agar plates and beta-hemolytic colonies were identified by MALDI-TOF (Bruker Microflex LT). Direct detection of GBS from clinical samples by MALDI-TOF MS was performed with 1mL of the pre-enriched broth, which was centrifuged, washed and the resulting pellet applied onto the MALDI target. Results and Discussion: Among 612 samples tested, 65 were positive in culture (10.6%) and 50 (8.2%) were positive by the alternative MALDI-TOF approach. MALDI-TOF mainly failed to detect GBS when the resulting pellet did not contain the minimum detection limit of the equipment. In these cases, subculturing onto blood agar plates or increasing the incubation period improved detection. The number of total agreements was 597 (97.55% of the observations). The sensitivity and specificity of the proposed method were high (81% and 100% respectively). The Kappa coefficient was 0.856 with 95% of confidence interval. MALDI-TOF method was faster; while the mean TAT for culture was 48h, the TAT of MALDI-TOF detection was 19h. Conclusions: Our results suggest that detection of GBS directly in clinical samples using MALDI-TOF MS is a suitable, fast, and reliable alternative for GBS screening among pregnant women. Such approach can aid to antimicrobial stewardship and lead to reduced rates of neonatal sepsis and meningitis.
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spelling doaj-art-8d7aeeee8e0c4e34b4b487ee7e18e3872025-08-20T02:17:08ZengElsevierInternational Journal of Infectious Diseases1201-97122025-03-0115210747010.1016/j.ijid.2024.107470A MALDI-TOF MS-based approach to improve group B Streptococcus screening among pregnant people in BrazilDr Tatiana Pinto0Debora Nery1Dr Laura Oliveira2Dr Natalia Costa3Prof Sergio Fracalanzza4Dr Ana Caroline Botelho5Prof Lucia Teixeira6Dr Penelope Marinho7Universidade Federal Do Rio De JaneiroUniversidade Federal Do Rio De JaneiroUniversidade Federal Do Rio De JaneiroUniversidade Federal Do Rio De JaneiroUniversidade Federal Do Rio De JaneiroUniversidade Federal Do Rio De JaneiroUniversidade Federal Do Rio De JaneiroUniversidade Federal Do Rio De JaneiroIntroduction: Group B Streptococcus (GBS) is a leading agent of sepsis and meningitis in neonates. Prevention is made by screening pregnant women at 36-37 gestational weeks and applying intrapartum antibiotic prophylaxis (IAP). However, GBS colonization in pregnant women can be transient or intermittent. GBS-negative women at 36-37 gestational week may be GBS-positive at the moment of labor, and vice-versa. Culture-based techniques have a long turnaround-time (TAT), and the development of a cost-effective, reliable and fast screening method that could be applied just before labor can aid to antimicrobial stewardship. Here we propose a MALDI-TOF-based protocol for GBS detection directly in pre-enriched clinical samples. Methods: Anovaginal samples of 612 women attending a maternity in Rio de Janeiro, Brazil, between July 2019 and May 2021, were processed as follows. After pre-enriching clinical samples for 18h at 36°C, they were subcultured onto blood agar plates and beta-hemolytic colonies were identified by MALDI-TOF (Bruker Microflex LT). Direct detection of GBS from clinical samples by MALDI-TOF MS was performed with 1mL of the pre-enriched broth, which was centrifuged, washed and the resulting pellet applied onto the MALDI target. Results and Discussion: Among 612 samples tested, 65 were positive in culture (10.6%) and 50 (8.2%) were positive by the alternative MALDI-TOF approach. MALDI-TOF mainly failed to detect GBS when the resulting pellet did not contain the minimum detection limit of the equipment. In these cases, subculturing onto blood agar plates or increasing the incubation period improved detection. The number of total agreements was 597 (97.55% of the observations). The sensitivity and specificity of the proposed method were high (81% and 100% respectively). The Kappa coefficient was 0.856 with 95% of confidence interval. MALDI-TOF method was faster; while the mean TAT for culture was 48h, the TAT of MALDI-TOF detection was 19h. Conclusions: Our results suggest that detection of GBS directly in clinical samples using MALDI-TOF MS is a suitable, fast, and reliable alternative for GBS screening among pregnant women. Such approach can aid to antimicrobial stewardship and lead to reduced rates of neonatal sepsis and meningitis.http://www.sciencedirect.com/science/article/pii/S1201971224005459
spellingShingle Dr Tatiana Pinto
Debora Nery
Dr Laura Oliveira
Dr Natalia Costa
Prof Sergio Fracalanzza
Dr Ana Caroline Botelho
Prof Lucia Teixeira
Dr Penelope Marinho
A MALDI-TOF MS-based approach to improve group B Streptococcus screening among pregnant people in Brazil
International Journal of Infectious Diseases
title A MALDI-TOF MS-based approach to improve group B Streptococcus screening among pregnant people in Brazil
title_full A MALDI-TOF MS-based approach to improve group B Streptococcus screening among pregnant people in Brazil
title_fullStr A MALDI-TOF MS-based approach to improve group B Streptococcus screening among pregnant people in Brazil
title_full_unstemmed A MALDI-TOF MS-based approach to improve group B Streptococcus screening among pregnant people in Brazil
title_short A MALDI-TOF MS-based approach to improve group B Streptococcus screening among pregnant people in Brazil
title_sort maldi tof ms based approach to improve group b streptococcus screening among pregnant people in brazil
url http://www.sciencedirect.com/science/article/pii/S1201971224005459
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