This repository contains scripts used to analyze data generated for the manuscript described below, inlcuding comparative analysis and visualization of nanoparticle tracking (quantification) and proteomics (composition) data of Group B Streptococcus membrane vesicles across various antibiotic treatment conditions.
Macy E. Pell, Cole R. McCutcheon, Jennifer A. Gaddy, David M. Aronoff, Margaret G. Petroff, Shannon D. Manning
Pell ME, McCutcheon CR, Gaddy JA, Aronoff DM, Petroff MG, Manning SD. 2025. Impact of antibiotics on membrane vesicle production in Group B Streptococcus. Microbiol Spectr 13:e03223-24. https://doi.org/10.1128/spectrum.03223-24
Group B Streptococcus (GBS) is an important bacterial pathogen during pregnancy, colonizing up to 35% of pregnant people recto-vaginally. Intrauterine GBS infection during pregnancy can cause preterm labor, early membrane rupture, and, if the fetus gets infected, stillbirth or early-onset disease (EOD) following birth. Intrapartum antibiotics are recommended to treat GBS-colonized pregnant patients during labor to prevent these outcomes, particularly EOD. However, persistent GBS colonization has been observed despite antibiotic treatment. One strategy employed by bacteria to promote survival and antibiotic tolerance is the production of membrane vesicles (MVs). To understand how GBS MVs are affected by antibiotics and influence bacterial survival, we exposed a clinical GBS strain recovered from a pregnant patient with persistent colonization to antibiotics and examined the impact on MV production and composition. Using nanoparticle tracking analysis, microscopy, and proteomics, antibiotic treatment of GBS was found to significantly increase the production of MVs relative to untreated GBS (control) regardless of the antibiotic class (ampicillin; P = 4.2 × 10−6, erythromycin; P = 0.01). Moreover, antibiotic exposure yielded MVs with different protein composition compared to the untreated control, with 21 and 19 proteins unique to the ampicillin- and erythromycin-treated GBS, respectively. Increased abundance of antibiotic-specific protein targets was observed in the respective antibiotic-treated MVs, suggesting a mechanism for evading antibiotic-mediated killing. Together, these data suggest that antibiotic treatment alters both the production and composition of MVs, which can promote GBS survival in such conditions.
GBS colonization during pregnancy can lead to invasive disease in neonates. Although antibiotics are given to GBS-positive pregnant patients during labor, some of these individuals remain colonized with GBS after treatment. Persistent GBS colonization is a public health concern, threatening the effectiveness of antibiotics and increasing the risk of GBS disease, especially for subsequent pregnancies. Although mechanisms linked to persistent colonization and antibiotic tolerance are poorly understood in GBS, MV production has been shown to promote bacterial survival in other species with and without antibiotic exposure. Herein, we demonstrated that two different antibiotics trigger changes in the production and composition of MVs in a persistent GBS colonizing strain, providing insight into the mechanisms used by GBS to rebound following antibiotic prophylaxis. Knowledge gained from this study can guide efforts in the development of more targeted and effective treatments for GBS disease.
Raw proteomic data has been uploaded to the MassIVE database under dataset MSV000094926 and can be accessed via doi:10.25345/C5RV0DB88. All other dataset and sample information can be found within supplementary data files associated with the manuscript.
We thank Soo H. Ahn and Geoffrey Grzesiak for technical assistance as well as Alicia Withrow, Carol Flegler, and Douglas Whitten for their assistance with microscopy and proteomics. We would also like to thank Drs. Kathryn Patras and Laura Cook for providing feedback on a prior version of this manuscript.Financial support was provided by the National Institutes of Health (NIH; AI154192 to S.D.M. and M.G.P.), the Michigan State University (MSU) Research Foundation (to S.D.M.) and, in part, by the Michigan Sequencing and Academic Partnerships for Public Health Innovation and Response (MI-SAPPHIRE) initiative at the MDHHS via CDC through the Epidemiology and Laboratory Capacity for Prevention and Control of Emerging Infectious Diseases Enhancing Detection Expansion program (6NU50CK000510-02-07; to S.D.M.). Salary support was provided by the National Institutes of Health (R01HD090061 to J.A.G. and S.D.M.) and the U.S. Department of Agriculture (2019-67017-29112) to S.D.M. Student support was provided to M.E.P. by the MSU Department of Microbiology, Genetics, and Immunology via the Philipp and Vera Gerhardt Travel and Ralph Evans Awards as well as the MSU College of Natural Science.Conceptualization: M.E.P., S.D.M.; methodology: M.E.P., C.R.M.; validation and formal analysis: M.E.P., C.R.M.; resources: S.D.M., M.G.P.; supervision and insight: S.D.M., M.G.P., J.A.G.; data curation: M.E.P., S.D.M.; writing—original draft preparation, M.E.P.; writing—review and editing and data visualization: all authors; funding acquisition: S.D.M., M.G.P., J.A.G. All authors have read and agreed to the final version of the manuscript.