1
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Pell ME, Blankenship HM, Gaddy JA, Davies HD, Manning SD. Intrapartum antibiotic prophylaxis selects for mutators in group B streptococci among persistently colonized patients. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.01.587590. [PMID: 38617326 PMCID: PMC11014637 DOI: 10.1101/2024.04.01.587590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Through vaginal colonization, GBS causes severe pregnancy outcomes including neonatal sepsis and meningitis. Although intrapartum antibiotic prophylaxis (IAP) has reduced early-onset disease rates, persistent GBS colonization has been observed in patients following prophylaxis. To determine whether IAP selects for genomic signatures that enhance GBS survival and persistence in the vaginal tract, whole-genome sequencing was performed on 97 isolates from 58 patients before (prenatal) and after (postpartum) IAP/childbirth. Core-gene mutation analysis identified 7,025 mutations between the paired isolates. Three postpartum isolates accounted for 98% of mutations and were classified as "mutators" because of point mutations within DNA repair systems. In vitro assays revealed stronger biofilms in two mutators. These findings suggest that antibiotics select for mutations that promote survival in vivo, which increases the likelihood of transmission to neonates. They also demonstrate how mutators can provide a reservoir of beneficial mutations that enhance fitness and genetic diversity in the GBS population.
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Affiliation(s)
- Macy E Pell
- Michigan State University, Department of Microbiology, Genetics, and Immunology (MGI), E. Lansing, MI
| | - Heather M Blankenship
- Michigan Department of Health and Human Services, Bureau of Laboratories, Division of Infectious Diseases, Lansing, MI
| | - Jennifer A Gaddy
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN
- Tennessee Valley Healthcare Systems, Department of Veterans Affairs, Nashville, TN
| | | | - Shannon D Manning
- Michigan State University, Department of Microbiology, Genetics, and Immunology (MGI), E. Lansing, MI
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2
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De-Leon-Lopez YS, Thompson ME, Kean JJ, Flaherty RA. The PI3K-Akt pathway is a multifaceted regulator of the macrophage response to diverse group B Streptococcus isolates. Front Cell Infect Microbiol 2023; 13:1258275. [PMID: 37928185 PMCID: PMC10622663 DOI: 10.3389/fcimb.2023.1258275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 09/25/2023] [Indexed: 11/07/2023] Open
Abstract
Group B Streptococcus (GBS), also known as Streptococcus agalactiae, is a common member of the microbial flora in healthy individuals. However, problems may arise when GBS-colonized mothers become pregnant. GBS may be transferred from a colonized mother to her newborn or developing fetus, which may result in complications such as miscarriage, pre-term birth, meningitis, pneumonia, or sepsis. Macrophages play an especially important role in the fetal and newborn response to GBS due to the limited development of the adaptive immune system early in life. The goal of this study was to expand what is currently known about how GBS manipulates macrophage cell signaling to evade the immune system and cause disease. To this end, we investigated whether the PI3K-Akt pathway was involved in several key aspects of the macrophage response to GBS. We explored whether certain GBS strains, such as sequence type (ST)-17 strains, rely on this pathway for the more rapid macrophage uptake they induce compared to other GBS strains. Our findings suggest that this pathway is, indeed, important for macrophage uptake of GBS. Consistent with these findings, we used immunofluorescence microscopy to demonstrate that more virulent strains of GBS induce more actin projections in macrophages than less virulent strains. Additionally, we explored whether PI3K-Akt signaling impacted the ability of GBS to survive within macrophages after phagocytosis and whether this pathway influenced the survival rate of macrophages themselves following GBS infection. The PI3K-Akt pathway was found to promote the survival of both macrophages and intracellular GBS following infection. We also observed that inhibition of the PI3K-Akt pathway significantly reduced GBS-mediated activation of NFκB, which is a key regulator of cell survival and inflammatory responses. Overall, these insights into strain-dependent GBS-mediated manipulation of the PI3K-Akt pathway and its downstream targets in infected macrophages may provide new insights for the development of diagnostic and therapeutic tools to combat severe GBS disease.
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Affiliation(s)
| | | | | | - Rebecca A. Flaherty
- Department of Biology and Health Science, Aquinas College, Grand Rapids, MI, United States
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3
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Korir ML, Doster RS, Lu J, Guevara MA, Spicer SK, Moore RE, Francis JD, Rogers LM, Haley KP, Blackman A, Noble KN, Eastman AJ, Williams JA, Damo SM, Boyd KL, Townsend SD, Henrique Serezani C, Aronoff DM, Manning SD, Gaddy JA. Streptococcus agalactiae cadD alleviates metal stress and promotes intracellular survival in macrophages and ascending infection during pregnancy. Nat Commun 2022; 13:5392. [PMID: 36104331 PMCID: PMC9474517 DOI: 10.1038/s41467-022-32916-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 08/24/2022] [Indexed: 01/17/2023] Open
Abstract
Perinatal infection with Streptococcus agalactiae, or Group B Streptococcus (GBS), is associated with preterm birth, neonatal sepsis, and stillbirth. Here, we study the interactions of GBS with macrophages, essential sentinel immune cells that defend the gravid reproductive tract. Transcriptional analyses of GBS-macrophage co-cultures reveal enhanced expression of a gene encoding a putative metal resistance determinant, cadD. Deletion of cadD reduces GBS survival in macrophages, metal efflux, and resistance to metal toxicity. In a mouse model of ascending infection during pregnancy, the ΔcadD strain displays attenuated bacterial burden, inflammation, and cytokine production in gestational tissues. Furthermore, depletion of host macrophages alters cytokine expression and decreases GBS invasion in a cadD-dependent fashion. Our results indicate that GBS cadD plays an important role in metal detoxification, which promotes immune evasion and bacterial proliferation in the pregnant host.
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Affiliation(s)
- Michelle L Korir
- Michigan State University, Department of Microbiology and Molecular Genetics, East Lansing, MI, USA
- Aurora University, Department of Biology, Aurora, IL, USA
| | - Ryan S Doster
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Medicine, University of Louisville, Louisville, KY, USA
| | - Jacky Lu
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Pathology, Stanford University, Palo Alto, CA, USA
| | - Miriam A Guevara
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Sabrina K Spicer
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA
| | - Rebecca E Moore
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA
| | - Jamisha D Francis
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Lisa M Rogers
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Kathryn P Haley
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Biomedical Sciences, Grand Valley State University, Allendale, MI, USA
| | - Amondrea Blackman
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kristen N Noble
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Alison J Eastman
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Janice A Williams
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD, USA
| | - Steven M Damo
- Department of Life and Physical Sciences, Fisk University, Nashville, TN, USA
- Department of Biochemistry and Structural Biology, Vanderbilt University, Nashville, TN, USA
| | - Kelli L Boyd
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | | | - C Henrique Serezani
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - David M Aronoff
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Obstetrics and Gynecology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Shannon D Manning
- Michigan State University, Department of Microbiology and Molecular Genetics, East Lansing, MI, USA.
| | - Jennifer A Gaddy
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.
- Center for Medicine, Health, and Society, Vanderbilt University, Nashville, TN, USA.
- Department of Veterans Affairs, Tennessee Valley Healthcare Systems, Nashville, TN, USA.
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4
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Furuta A, Brokaw A, Manuel G, Dacanay M, Marcell L, Seepersaud R, Rajagopal L, Adams Waldorf K. Bacterial and Host Determinants of Group B Streptococcal Infection of the Neonate and Infant. Front Microbiol 2022; 13:820365. [PMID: 35265059 PMCID: PMC8899651 DOI: 10.3389/fmicb.2022.820365] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 01/27/2022] [Indexed: 12/15/2022] Open
Abstract
Group B streptococci (GBS) are Gram-positive β-hemolytic bacteria that can cause serious and life-threatening infections in neonates manifesting as sepsis, pneumonia, meningitis, osteomyelitis, and/or septic arthritis. Invasive GBS infections in neonates in the first week of life are referred to as early-onset disease (EOD) and thought to be acquired by the fetus through exposure to GBS in utero or to vaginal fluids during birth. Late-onset disease (LOD) refers to invasive GBS infections between 7 and 89 days of life. LOD transmission routes are incompletely understood, but may include breast milk, household contacts, nosocomial, or community sources. Invasive GBS infections and particularly meningitis may result in significant neurodevelopmental injury and long-term disability that persists into childhood and adulthood. Globally, EOD and LOD occur in more than 300,000 neonates and infants annually, resulting in 90,000 infant deaths and leaving more than 10,000 infants with a lifelong disability. In this review, we discuss the clinical impact of invasive GBS neonatal infections and then summarize virulence and host factors that allow the bacteria to exploit the developing neonatal immune system and target organs. Specifically, we consider the mechanisms known to enable GBS invasion into the neonatal lung, blood vessels and brain. Understanding mechanisms of GBS invasion and pathogenesis relevant to infections in the neonate and infant may inform the development of therapeutics to prevent or mitigate injury, as well as improve risk stratification.
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Affiliation(s)
- Anna Furuta
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States
| | - Alyssa Brokaw
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States
| | - Gygeria Manuel
- Morehouse School of Medicine, Atlanta, GA, United States
| | - Matthew Dacanay
- Department of Obstetrics & Gynecology, University of Washington, Seattle, WA, United States
| | - Lauren Marcell
- Department of Obstetrics & Gynecology, University of Washington, Seattle, WA, United States
| | - Ravin Seepersaud
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Lakshmi Rajagopal
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States.,Department of Pediatrics, University of Washington, Seattle, WA, United States
| | - Kristina Adams Waldorf
- Department of Global Health, University of Washington, Seattle, WA, United States.,Department of Obstetrics & Gynecology, University of Washington, Seattle, WA, United States.,Department of Obstetrics and Gynecology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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5
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McCutcheon CR, Pell ME, Gaddy JA, Aronoff DM, Petroff MG, Manning SD. Production and Composition of Group B Streptococcal Membrane Vesicles Vary Across Diverse Lineages. Front Microbiol 2021; 12:770499. [PMID: 34880842 PMCID: PMC8645895 DOI: 10.3389/fmicb.2021.770499] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 10/28/2021] [Indexed: 11/17/2022] Open
Abstract
Although the neonatal and fetal pathogen Group B Streptococcus (GBS) asymptomatically colonizes the vaginal tract of ∼30% of pregnant women, only a fraction of their offspring develops invasive disease. We and others have postulated that these dimorphic clinical phenotypes are driven by strain variability; however, the bacterial factors that promote these divergent clinical phenotypes remain unclear. It was previously shown that GBS produces membrane vesicles (MVs) that contain active virulence factors capable of inducing adverse pregnancy outcomes. Because the relationship between strain variation and vesicle composition or production is unknown, we sought to quantify MV production and examine the protein composition, using label-free proteomics on MVs produced by diverse clinical GBS strains representing three phylogenetically distinct lineages. We found that MV production varied across strains, with certain strains displaying nearly twofold increases in production relative to others. Hierarchical clustering and principal component analysis of the proteomes revealed that MV composition is lineage-dependent but independent of clinical phenotype. Multiple proteins that contribute to virulence or immunomodulation, including hyaluronidase, C5a peptidase, and sialidases, were differentially abundant in MVs, and were partially responsible for this divergence. Together, these data indicate that production and composition of GBS MVs vary in a strain-dependent manner, suggesting that MVs have lineage-specific functions relating to virulence. Such differences may contribute to variation in clinical phenotypes observed among individuals infected with GBS strains representing distinct lineages.
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Affiliation(s)
- Cole R. McCutcheon
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States
| | - Macy E. Pell
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States
| | - Jennifer A. Gaddy
- Division of Infectious Disease, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States
- Tennessee Valley Healthcare System, Department of Veterans Affairs, Nashville, TN, United States
| | - David M. Aronoff
- Division of Infectious Disease, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Obstetrics and Gynecology, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Margaret G. Petroff
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States
- Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, MI, United States
| | - Shannon D. Manning
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States
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6
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Distinct Group B Streptococcus Sequence and Capsule Types Differentially Impact Macrophage Stress and Inflammatory Signaling Responses. Infect Immun 2021; 89:IAI.00647-20. [PMID: 33558317 PMCID: PMC8091095 DOI: 10.1128/iai.00647-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 01/27/2021] [Indexed: 12/15/2022] Open
Abstract
Group B Streptococcus (GBS) is an opportunistic bacterial pathogen that can contribute to the induction of preterm birth in colonized pregnant women and to severe neonatal disease. Many questions regarding the mechanisms that drive GBS-associated pathogenesis remain unanswered, and it is not yet clear why virulence has been observed to vary so extensively across GBS strains. Group B Streptococcus (GBS) is an opportunistic bacterial pathogen that can contribute to the induction of preterm birth in colonized pregnant women and to severe neonatal disease. Many questions regarding the mechanisms that drive GBS-associated pathogenesis remain unanswered, and it is not yet clear why virulence has been observed to vary so extensively across GBS strains. Previously, we demonstrated that GBS strains of different sequence types (STs) and capsule (CPS) types induce different cytokine profiles in infected THP-1 macrophage-like cells. Here, we expanded on these studies by utilizing the same set of genetically diverse GBS isolates to assess ST and CPS-specific differences in upstream cell death and inflammatory signaling pathways. Our results demonstrate that particularly virulent STs and CPS types, such as the ST-17 and CPS III groups, induce enhanced Jun-N-terminal protein kinase (JNK) and NF-κB pathway activation following GBS infection of macrophages compared with other ST or CPS groups. Additionally, we found that ST-17, CPS III, and CPS V GBS strains induce the greatest levels of macrophage cell death during infection and exhibit a more pronounced ability to be internalized and to survive in macrophages following phagocytosis. These data provide further support for the hypothesis that variable host innate immune responses to GBS, which significantly impact pathogenesis, stem in part from genotypic and phenotypic differences among GBS isolates. These and similar studies may inform the development of improved diagnostic, preventive, or therapeutic strategies targeting invasive GBS infections.
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7
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Shiroda M, Manning SD. Lactobacillus strains vary in their ability to interact with human endometrial stromal cells. PLoS One 2020; 15:e0238993. [PMID: 32925983 PMCID: PMC7489503 DOI: 10.1371/journal.pone.0238993] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 08/27/2020] [Indexed: 12/17/2022] Open
Abstract
The placental membranes that surround the fetus during pregnancy were suggested to contain a low abundance microbiota. Specifically, abundance of Lactobacillus, a probiotic and dominant member of the microbiome of the lower reproductive tract, has been shown to correlate with healthy, term pregnancies. We therefore sought to assess the interactions between four different Lactobacillus strains with immortalized decidualized endometrial cells (dT-HESCs), which were used as a model to represent the outermost layer of the placental membranes. Notably, we demonstrated that all four Lactobacillus strains could associate with dT-HESCs in vitro. L. crispatus was significantly more successful (p < 0.00005), with 10.6% of bacteria attaching to the host cells compared to an average of 0.8% for the remaining three strains. The four strains also varied in their ability to form biofilms. Dependent on media type, L. reuteri 6475 formed the strongest biofilms in vitro. To examine the impact on immune responses, levels of total and phosphorylated protein p38, a member of the Mitogen Activated Protein Kinase (MAPK) pathway, were examined following Lactobacillus association with dT-HESCs. Total levels of p38 were reduced to an average of 44% that of the cells without Lactobacillus (p < 0.05). While a trend towards a reduction in phosphorylated p38 was observed, this difference was not significant (p > 0.05). In addition, association with Lactobacillus did not result in increased host cell death. Collectively, these data suggest that varying types of Lactobacillus can attach to the outermost cells of the placental membranes and that these interactions do not contribute to inflammatory responses or host cell death. To our knowledge this is the first in vitro study to support the ability of Lactobacillus to interact with placental cells, which is important when considering its use as a potential probiotic within the reproductive tract.
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Affiliation(s)
- Megan Shiroda
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States of America
| | - Shannon D. Manning
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States of America
- * E-mail:
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8
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Yoshida H, Goto M, Fukushima Y, Maeda T, Tsuyuki Y, Takahashi T. Intracellular Invasion Ability and Associated Microbiological Characteristics of Streptococcus canis in Isolates from Japan. Jpn J Infect Dis 2020; 74:129-136. [PMID: 32863352 DOI: 10.7883/yoken.jjid.2020.382] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This study evaluated the cell invasion ability (CIA) of Streptococcus canis isolates, and clarified the relationship between high-frequency CIA and its microbiological features. Of the companion animal-origin isolates (n = 117) that were obtained in 2017, 40 isolates were randomly selected with the host information, with two human blood-origin isolates included. CIA was measured using human colon carcinoma epithelium and the hemolytic activity (HA) using sheep blood, along with S. canis M-like protein (SCM) allele typing, sequence type (ST) determination, and antimicrobial resistance (AMR) phenotyping/genotyping. CIA measurements revealed that 19 and 24 isolates had high- and low-frequencies, respectively. HA assessment revealed that 24 and 19 isolates were categorized as high- and low- level, respectively. No difference was observed in the high-/low-level HA between the high- /low-frequency CIA populations. A significant difference was found in the high-/low-frequency CIA between the SCM group I/II populations. Additionally, a significantly higher CIA was found in the SCM allele type 10/type 11 than in the others. A significant association was observed between high-frequency CIA and the ST21/ST41 populations. No difference was found in the high-/low-frequency CIA between the presence and absence of the AMR phenotype/genotype. These observations suggest a relationship between high-frequency CIA and its microbiological characteristics (SCM allele type 10/type 11 or ST21/ST41).
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Affiliation(s)
- Haruno Yoshida
- Laboratory of Infectious Diseases, Graduate School of Infection Control Sciences & Ōmura Satoshi Memorial Institute, Kitasato University, Japan
| | - Mieko Goto
- Laboratory of Infectious Diseases, Graduate School of Infection Control Sciences & Ōmura Satoshi Memorial Institute, Kitasato University, Japan
| | - Yasuto Fukushima
- Laboratory of Infectious Diseases, Graduate School of Infection Control Sciences & Ōmura Satoshi Memorial Institute, Kitasato University, Japan
| | - Takahiro Maeda
- Laboratory of Infectious Diseases, Graduate School of Infection Control Sciences & Ōmura Satoshi Memorial Institute, Kitasato University, Japan
| | - Yuzo Tsuyuki
- Laboratory of Infectious Diseases, Graduate School of Infection Control Sciences & Ōmura Satoshi Memorial Institute, Kitasato University, Japan.,Division of Clinical Laboratory, Sanritsu Zelkova Veterinary Laboratory, Japan
| | - Takashi Takahashi
- Laboratory of Infectious Diseases, Graduate School of Infection Control Sciences & Ōmura Satoshi Memorial Institute, Kitasato University, Japan
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9
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Shiroda M, Aronoff DM, Gaddy JA, Manning SD. The impact of Lactobacillus on group B streptococcal interactions with cells of the extraplacental membranes. Microb Pathog 2020; 148:104463. [PMID: 32828901 DOI: 10.1016/j.micpath.2020.104463] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 08/12/2020] [Accepted: 08/18/2020] [Indexed: 01/27/2023]
Abstract
Group B Streptococcus (GBS) causes adverse pregnancy outcomes and neonatal disease. The recommended preventative measure is intrapartum antibiotic prophylaxis, which can prevent early onset neonatal disease but not chorioamnionitis, preterm labor, stillbirth, or late-onset disease. Novel prevention methods are therefore needed. Use of probiotics including Lactobacillus spp., has been suggested given that they are dominant members of the lower reproductive tract microbiome. Although Lactobacillus was shown to reduce recto-vaginal colonization of GBS, no studies have examined how Lactobacillus impacts GBS in the extraplacental membranes. Since Lactobacillus has been detected in the placental membranes, we sought to characterize GBS-Lactobacillus interactions in vitro using a colonizing and invasive GBS strain. While live Lactobacillus did not affect growth or biofilms in GBS, co-culture with L. gasseri led to a 224-fold increase in GBS association with decidualized human endometrial stromal cells for both GBS strains (p < 0.005). Increased association did not result in increased invasion (p > 0.05) or host cell death, though some GBS and Lactobacillus combinations contributed to a significant reduction in host cell death (p < 0.05). Since Lactobacillus secretes many inhibitory compounds, the effect of Lactobacillus supernatants on GBS was also examined. The supernatants inhibited GBS growth, biofilm formation and invasion of host cells, though strain dependent effects were observed. Notably, supernatant from L. reuteri 6475 broadly inhibited growth in 36 distinct GBS strains and inhibited GBS growth to an average of 46.6% of each GBS strain alone. Together, these data show that specific Lactobacillus strains and their secreted products have varying effects on GBS interactions with cells of the extraplacental membranes that could impact pathogenesis. Understanding these interactions could help guide new treatment options aimed at reducing GBS-associated maternal complications and disease.
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Affiliation(s)
- Megan Shiroda
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
| | - David M Aronoff
- Department of Medicine, Division of Infectious Disease, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Obstetrics and Gynecology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jennifer A Gaddy
- Department of Medicine, Division of Infectious Disease, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Tennessee Valley Healthcare System, Department of Veterans Affairs, Nashville, TN, USA
| | - Shannon D Manning
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA.
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10
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Modulation of Death and Inflammatory Signaling in Decidual Stromal Cells following Exposure to Group B Streptococcus. Infect Immun 2019; 87:IAI.00729-19. [PMID: 31548323 DOI: 10.1128/iai.00729-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 09/18/2019] [Indexed: 02/07/2023] Open
Abstract
Group B Streptococcus (GBS) is an opportunistic bacterial pathogen that contributes to miscarriage, preterm birth, and serious neonatal infections. Studies have indicated that some multilocus sequence types (STs) of GBS are more likely to cause severe disease than others. We hypothesized that the ability of GBS to elicit varying host responses in maternal decidual tissue during pregnancy is an important factor regulating infection and disease severity. To address this hypothesis, we utilized an antibody microarray to compare changes in production and activation of host signaling proteins in decidualized telomerase-immortalized human endometrial stromal cells (dT-HESCs) following infection with GBS strains from septic neonates or colonized mothers. GBS infection increased levels of total and phosphorylated mitogen-activated protein kinase (MAPK) family members such as p38 and JNK and induced nuclear factor kappa B (NF-κB) pathway activation. Infection also altered the regulation of additional proteins that mediate cell death and inflammation in a strain-specific manner, which could be due to the observed variation in attachment to and invasion of the decidual stromal cells and ability to lyse red blood cells. Further analyses confirmed array results and revealed that p38 promotes programmed necrosis in dT-HESCs. Together, the observed signaling changes may contribute to deregulation of critical developmental signaling cascades and inflammatory responses following infection, both of which could trigger GBS-associated pregnancy complications.
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11
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Flaherty RA, Borges EC, Sutton JA, Aronoff DM, Gaddy JA, Petroff MG, Manning SD. Genetically distinct Group B Streptococcus strains induce varying macrophage cytokine responses. PLoS One 2019; 14:e0222910. [PMID: 31536604 PMCID: PMC6752832 DOI: 10.1371/journal.pone.0222910] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 09/10/2019] [Indexed: 12/18/2022] Open
Abstract
Group B Streptococcus (GBS) is an opportunistic pathogen that causes preterm birth and neonatal disease. Although GBS is known to exhibit vast diversity in virulence across strains, the mechanisms of GBS-associated pathogenesis are incompletely understood. We hypothesized that GBS strains of different genotypes would vary in their ability to elicit host inflammatory responses, and that strains associated with neonatal disease would induce different cytokine profiles than those associated with colonization. Using a multiplexed, antibody-based protein detection array, we found that production of a discrete number of inflammatory mediators by THP-1 macrophage-like cells was universally induced in response to challenge with each of five genetically distinct GBS isolates, while other responses appeared to be strain-specific. Key array responses were validated by ELISA using the initial five strains as well as ten additional strains with distinct genotypic and phenotypic characteristics. Interestingly, IL-6 was significantly elevated following infection with neonatal infection-associated sequence type (ST)-17 strains and among strains possessing capsule (cps) type III. Significant differences in production of IL1-β, IL-10 and MCP-2 were also identified across STs and cps types. These data support our hypothesis and suggest that unique host innate immune responses reflect strain-specific differences in virulence across GBS isolates. Such data might inform the development of improved diagnostic or prognostic strategies against invasive GBS infections.
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Affiliation(s)
- Rebecca A. Flaherty
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States of America
| | - Elena C. Borges
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States of America
| | - Jessica A. Sutton
- Department of Microbiology and Immunology, Meharry Medical College School of Medicine, Nashville, TN, United States of America
- Department of Medicine, Division of Infectious Disease, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - David M. Aronoff
- Department of Medicine, Division of Infectious Disease, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Jennifer A. Gaddy
- Department of Medicine, Division of Infectious Disease, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Margaret G. Petroff
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States of America
- Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, MI, United States of America
| | - Shannon D. Manning
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States of America
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Bacterial Load and Molecular Markers Associated With Early-onset Group B Streptococcus: A Systematic Review and Meta-analysis. Pediatr Infect Dis J 2018; 37:e306-e314. [PMID: 29601454 DOI: 10.1097/inf.0000000000002050] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND The natural history of neonatal group B Streptococcus (GBS) is poorly understood. Little is known about the bacterial factors influencing the transmission of GBS from mother to neonate, or the development of invasive early-onset GBS disease (EOGBS) in colonized neonates. We reviewed whether bacterial load and molecular markers are associated with GBS vertical transmission and progression to EOGBS. METHODS We searched Medline, Embase, Cochrane and Web of Science from inception to October 10, 2016, for observational studies in English. We also hand-searched reference lists of relevant publications and experts cross-checked included studies. Two reviewers independently screened studies, extracted data and appraised the quality of included studies using the Quality in Prognosis Studies tool. We conducted random-effects meta-analyses where possible and narratively synthesized the evidence in text and tables. RESULTS Seventeen studies were included from 1107 records retrieved from electronic databases and publication references. Meta-analyses of 3 studies showed that neonates colonized by serotype III had a higher risk of developing EOGBS than serotype Ia (pooled risk ratio: 1.51, 95% confidence interval: 1.12-2.03) and serotype II (risk ratio: 1.95, 95% confidence interval: 1.10-3.45). Eleven studies showed that in heavily colonized mothers, 2-3 times more neonates were colonized, and in heavily colonized neonates, up to 15 times more neonates had EOGBS, compared with light colonization. Most evidence was published before 2000 and was at risk of bias. CONCLUSIONS Acknowledging the difficulty of natural history studies, well-controlled studies are needed to assess the predictive value of pathogen subtype and heavy load; they may be useful for better-targeted prevention.
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13
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Korir ML, Flaherty RA, Rogers LM, Gaddy JA, Aronoff DM, Manning SD. Investigation of the Role That NADH Peroxidase Plays in Oxidative Stress Survival in Group B Streptococcus. Front Microbiol 2018; 9:2786. [PMID: 30515142 PMCID: PMC6255910 DOI: 10.3389/fmicb.2018.02786] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 10/30/2018] [Indexed: 02/02/2023] Open
Abstract
Macrophages play an important role in defending the host against infections by engulfing pathogens and containing them inside the phagosome, which consists of a harsh microbicidal environment. However, many pathogens have developed mechanisms to survive inside macrophages despite this challenge. Group B Streptococcus (GBS), a leading cause of sepsis and meningitis in neonates, is one such pathogen that survives inside macrophages by withstanding phagosomal stress. Although a few key intracellular survival factors have been identified, the mechanisms by which GBS detoxifies the phagosome are poorly defined. Transcriptional analysis during survival inside macrophages revealed strong upregulation of a putative NADH peroxidase (npx) at 1 and 24 h post-infection. A deletion mutant of npx (Δnpx) was more susceptible to killing by a complex in vitro model of multiple phagosomal biochemical/oxidant stressors or by hydrogen peroxide alone. Moreover, compared to an isogenic wild type GBS strain, the Δnpx strain demonstrated impaired survival inside human macrophages and a reduced capacity to blunt macrophage reactive oxygen species (ROS) production. It is therefore likely that Npx plays a role in survival against ROS production in the macrophage. A more thorough understanding of how GBS evades the immune system through survival inside macrophages will aid in development of new therapeutic measures.
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Affiliation(s)
- Michelle L Korir
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States
| | - Rebecca A Flaherty
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States
| | - Lisa M Rogers
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Jennifer A Gaddy
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States.,Tennessee Valley Healthcare Systems, Department of Veterans Affairs, Nashville, TN, United States.,Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States
| | - David M Aronoff
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States.,Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States.,Department of Obstetrics and Gynecology, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Shannon D Manning
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States
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14
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Moraleda C, Benmessaoud R, Esteban J, López Y, Alami H, Barkat A, Houssain T, Kabiri M, Bezad R, Chaacho S, Madrid L, Vila J, Muñoz-Almagro C, Bosch J, Soto SM, Bassat Q. Prevalence, antimicrobial resistance and serotype distribution of group B streptococcus isolated among pregnant women and newborns in Rabat, Morocco. J Med Microbiol 2018. [PMID: 29543148 DOI: 10.1099/jmm.0.000720] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Purpose. Group B streptococcus (GBS) is an important cause of neonatal sepsis worldwide. Data on the prevalence of maternal GBS colonization, risk factors for carriage, antibiotic susceptibility and circulating serotypes are necessary to tailor adequate locally relevant public health policies.Methodology. A prospective study including pregnant women and their newborns was conducted between March and July 2013 in Morocco. We collected clinical data and vagino-rectal and urine samples from the recruited pregnant women, together with the clinical characteristics of, and body surface samples from, their newborns. Additionally, the first three newborns admitted every day with suspected invasive infection were recruited for a thorough screening for neonatal sepsis. Serotypes were characterized by molecular testing.Results. A total of 350 pregnant women and 139 of their newborns were recruited. The prevalence of pregnant women colonized by GBS was 24 %. In 5/160 additional sick newborns recruited with suspected sepsis, the blood cultures were positive for GBS. Gestational hypertension and vaginal pruritus were significantly associated with a vagino-rectal GBS colonization in univariate analyses. All of the strains were susceptible to penicillin, while 7 % were resistant to clindamycin and 12 % were resistant to erythromycin. The most common GBS serotypes detected included V, II and III.Conclusion. In Morocco, maternal GBS colonization is high. Penicillin can continue to be the cornerstone of intrapartum antibiotic prophylaxis. A pentavalent GBS vaccine (Ia, Ib, II, III and V) would have been effective against the majority of the colonizing cases in this setting, but a trivalent one (Ia, Ib and III) would only prevent 28 % of the cases.
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Affiliation(s)
- Cinta Moraleda
- Sección de Enfermedades Infecciosas de Pediatría, Hospital Universitario 12 de Octubre, Universidad Complutense, Instituto de Investigación Hospital 12 de Octubre, Madrid, Spain
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Rachid Benmessaoud
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
- Laboratoire National de Reference, BD Mohamed Taieb Naciri, Hay el Hassani, Casablanca, Morocco
| | - Jessica Esteban
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Yuly López
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Hassan Alami
- Équipe de Recherche de Périnatologie, Université Mohammed V, Rabat, Morocco
| | - Amina Barkat
- Équipe de Recherche en Santé et Nutrition du Couple Mère Enfant, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Morocco
| | - Tligui Houssain
- Laboratoire de Recherche. Centre Hôpitalier Universitaire (CHU) Ibn Sina, Rabat, Morocco
| | - Meryem Kabiri
- Équipe de Recherche en Santé et Nutrition du Couple Mère Enfant, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Morocco
| | - Rachid Bezad
- Équipe de Recherche de Périnatologie, Université Mohammed V, Rabat, Morocco
| | - Saad Chaacho
- Centre Hôpitalier Universitaire (CHU) Ibn Sina, Rabat, Morocco
| | - Lola Madrid
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Jordi Vila
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
- School of Medicine, University of Barcelona, Barcelona, Spain
| | - Carmen Muñoz-Almagro
- Department of Molecular Microbiology, University Hospital Sant Joan de Deu, Barcelona, Spain
- School of Medicine, Universitat Internacional de Catalunya, Barcelona, Spain
- Ciber de Epidemiología y Salud Pública, CIBERESP, Madrid, Spain
| | - Jordi Bosch
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
- School of Medicine, University of Barcelona, Barcelona, Spain
| | - Sara M Soto
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Quique Bassat
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
- Pediatric Infectious Diseases Unit, Pediatrics Department, Hospital Sant Joan de Déu (University of Barcelona), Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
- ICREA, Pg Lluís Companys 23, 08010 Barcelona, Spain
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15
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Intrinsic Maturational Neonatal Immune Deficiencies and Susceptibility to Group B Streptococcus Infection. Clin Microbiol Rev 2017; 30:973-989. [PMID: 28814408 DOI: 10.1128/cmr.00019-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Although a normal member of the gastrointestinal and vaginal microbiota, group B Streptococcus (GBS) can also occasionally be the cause of highly invasive neonatal disease and is an emerging pathogen in both elderly and immunocompromised adults. Neonatal GBS infections are typically transmitted from mother to baby either in utero or during passage through the birth canal and can lead to pneumonia, sepsis, and meningitis within the first few months of life. Compared to the adult immune system, the neonatal immune system has a number of deficiencies, making neonates more susceptible to infection. Recognition of GBS by the host immune system triggers an inflammatory response to clear the pathogen. However, GBS has developed several mechanisms to evade the host immune response. A comprehensive understanding of this interplay between GBS and the host immune system will aid in the development of new preventative measures and therapeutics.
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16
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Parker RE, Knupp D, Al Safadi R, Rosenau A, Manning SD. Contribution of the RgfD Quorum Sensing Peptide to rgf Regulation and Host Cell Association in Group B Streptococcus. Genes (Basel) 2017; 8:genes8010023. [PMID: 28067833 PMCID: PMC5295018 DOI: 10.3390/genes8010023] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 12/29/2016] [Accepted: 01/04/2017] [Indexed: 11/16/2022] Open
Abstract
Streptococcus agalactiae (group B Streptococcus; GBS) is a common inhabitant of the genitourinary and/or gastrointestinal tract in up to 40% of healthy adults; however, this opportunistic pathogen is able to breach restrictive host barriers to cause disease and persist in harsh and changing conditions. This study sought to identify a role for quorum sensing, a form of cell to cell communication, in the regulation of the fibrinogen-binding (rgfBDAC) two-component system and the ability to associate with decidualized endometrial cells in vitro. To do this, we created a deletion in rgfD, which encodes the putative autoinducing peptide, in a GBS strain belonging to multilocus sequence type (ST)-17 and made comparisons to the wild type. Sequence variation in the rgf operon was detected in 40 clinical strains and a non-synonymous single nucleotide polymorphism was detected in rgfD in all of the ST-17 genomes that resulted in a truncation. Using qPCR, expression of rgf operon genes was significantly decreased in the ST-17 ΔrgfD mutant during exponential growth with the biggest difference (3.3-fold) occurring at higher cell densities. Association with decidualized endometrial cells was decreased 1.3-fold in the mutant relative to the wild type and rgfC expression was reduced 22-fold in ΔrgfD following exposure to the endometrial cells. Collectively, these data suggest that this putative quorum sensing molecule is important for attachment to human tissues and demonstrate a role for RgfD in GBS pathogenesis through regulation of rgfC.
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Affiliation(s)
- Robert E Parker
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA.
| | - David Knupp
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA.
| | - Rim Al Safadi
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA.
| | - Agnѐs Rosenau
- Infectiologie et Santé Publique ISP, Institut National de la Recherche Agronomique, Université de Tours, Equipe Bactéries et Risque Materno-fœtal, UMR1282 Tours, France.
| | - Shannon D Manning
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA.
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17
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Anders AP, Gaddy JA, Doster RS, Aronoff DM. Current concepts in maternal-fetal immunology: Recognition and response to microbial pathogens by decidual stromal cells. Am J Reprod Immunol 2017; 77. [PMID: 28044385 DOI: 10.1111/aji.12623] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 11/21/2016] [Indexed: 12/29/2022] Open
Abstract
Chorioamnionitis is an acute inflammation of the gestational (extraplacental) membranes, most commonly caused by ascending microbial infection. It is associated with adverse neonatal outcomes including preterm birth, neonatal sepsis, and cerebral palsy. The decidua is the outermost layer of the gestational membranes and is likely an important initial site of contact with microbes during ascending infection. However, little is known about how decidual stromal cells (DSCs) respond to microbial threat. Defining the contributions of individual cell types to the complex medley of inflammatory signals during chorioamnionitis could lead to improved interventions aimed at halting this disease. We review available published data supporting the role for DSCs in responding to microbial infection, with a special focus on their expression of pattern recognition receptors and evidence of their responsiveness to pathogen sensing. While DSCs likely play an important role in sensing and responding to infection during the pathogenesis of chorioamnionitis, important knowledge gaps and areas for future research are highlighted.
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Affiliation(s)
- Anjali P Anders
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jennifer A Gaddy
- Tennessee Valley Healthcare Systems, Department of Veterans Affairs, Nashville, TN, USA.,Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Ryan S Doster
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - David M Aronoff
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.,Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
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18
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Korir ML, Laut C, Rogers LM, Plemmons JA, Aronoff DM, Manning SD. Differing mechanisms of surviving phagosomal stress among group B Streptococcus strains of varying genotypes. Virulence 2016; 8:924-937. [PMID: 27791478 DOI: 10.1080/21505594.2016.1252016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Group B Streptococcus (GBS), a leading cause of neonatal sepsis and meningitis, asymptomatically colonizes up to 30% of women and can persistently colonize even after antibiotic treatment. Previous studies have shown that GBS resides inside macrophages, but the mechanism by which it survives remains unknown. Here, we examined the ability of 4 GBS strains to survive inside macrophages and then focused on 2 strains belonging to sequence type (ST)-17 and ST-12, to examine persistence in the presence of antibiotics. A multiple stress medium was also developed using several stressors found in the phagosome to assess the ability of 30 GBS strains to withstand phagosomal stress. The ST-17 strain was more readily phagocytosed and survived intracellularly longer than the ST-12 strain, but the ST-12 strain was tolerant to ampicillin unlike the ST-17 strain. Exposure to sub-inhibitory concentrations of ampicillin and erythromycin increased the level of phagocytosis of the ST-17 strain, but had no effect on the ST-12 strain. In addition, blocking acidification of the phagosome decreased the survival of the ST-17 strain indicating a pH-dependent survival mechanism for the ST-17 strain. Congruent with the macrophage experiments, the ST-17 strain had a higher survival rate in the multiple stress medium than the ST-12 strain, and overall, serotype III isolates survived significantly better than other serotypes. These results indicate that diverse GBS strains may use differing mechanisms to persist and that serotype III strains are better able to survive specific stressors inside the phagosome relative to other serotypes.
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Affiliation(s)
- Michelle L Korir
- a Department of Microbiology and Molecular Genetics , Michigan State University , East Lansing , MI , USA
| | - Clare Laut
- a Department of Microbiology and Molecular Genetics , Michigan State University , East Lansing , MI , USA
| | - Lisa M Rogers
- b Department of Medicine , Vanderbilt University , Nashville , TN , USA
| | - Jessica A Plemmons
- a Department of Microbiology and Molecular Genetics , Michigan State University , East Lansing , MI , USA
| | - David M Aronoff
- b Department of Medicine , Vanderbilt University , Nashville , TN , USA
| | - Shannon D Manning
- a Department of Microbiology and Molecular Genetics , Michigan State University , East Lansing , MI , USA
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19
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Jiang H, Chen M, Li T, Liu H, Gong Y, Li M. Molecular Characterization of Streptococcus agalactiae Causing Community- and Hospital-Acquired Infections in Shanghai, China. Front Microbiol 2016; 7:1308. [PMID: 27625635 PMCID: PMC5003847 DOI: 10.3389/fmicb.2016.01308] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 08/08/2016] [Indexed: 12/21/2022] Open
Abstract
Streptococcus agalactiae, a colonizing agent in pregnant women and the main cause of neonatal sepsis and meningitis, has been increasingly associated with invasive disease in nonpregnant adults. We collected a total of 87 non-repetitive S. agalactiae isolates causing community-acquired (CA) and hospital-acquired (HA) infections in nonpregnant adults from a teaching hospital in Shanghai between 2009 and 2013. We identified and characterized their antibiotic resistance, sequence type (ST), serotype, virulence, and biofilm formation. The most frequent STs were ST19 (29.9%), ST23 (16.1%), ST12 (13.8%), and ST1 (12.6%). ST19 had significantly different distributions between CA- and HA-group B Streptococci (GBS) isolates. The most frequent serotypes were III (32.2%), Ia (26.4%), V (14.9%), Ib (13.8%), and II (5.7%). Serotype III/ST19 was significantly associated with levofloxacin resistance in all isoates. The HA-GBS multidrug resistant rate was much higher than that of CA-GBS. Virulence genes pavA, cfb were found in all isolates. Strong correlations exist between serotype Ib (CA and HA) and surface protein genes spb1 and bac, serotype III (HA) and surface protein gene cps and GBS pilus cluster. The serotype, epidemic clone, PFGE-based genotype, and virulence gene are closely related between CA-GBS and HA-GBS, and certain serotypes and clone types were significantly associated with antibiotic resistance. However, CA-GBS and HA-GBS still had significant differences in their distribution of clone types, antibiotic resistance, and specific virulence genes, which may provide a basis for infection control.
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Affiliation(s)
- Haoqin Jiang
- Department of Laboratory Medicine, Shanghai Medical College, Huashan Hospital, Fudan University Shanghai, China
| | - Mingliang Chen
- Shanghai Municipal Center for Disease Control and PreventionShanghai, China; Shanghai Institutes of Preventive MedicineShanghai, China
| | - Tianming Li
- Department of Laboratory Medicine, School of Medicine, Renji Hospital, Shanghai Jiao Tong University Shanghai, China
| | - Hong Liu
- Department of Laboratory Medicine, Shanghai Medical College, Huashan Hospital, Fudan University Shanghai, China
| | - Ye Gong
- Department of Critical Care Medicine, Shanghai Medical College, Huashan Hospital, Fudan University Shanghai, China
| | - Min Li
- Department of Laboratory Medicine, School of Medicine, Renji Hospital, Shanghai Jiao Tong University Shanghai, China
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20
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Parker RE, Laut C, Gaddy JA, Zadoks RN, Davies HD, Manning SD. Association between genotypic diversity and biofilm production in group B Streptococcus. BMC Microbiol 2016; 16:86. [PMID: 27206613 PMCID: PMC4875601 DOI: 10.1186/s12866-016-0704-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 05/10/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Group B Streptococcus (GBS) is a leading cause of sepsis and meningitis and an important factor in premature and stillbirths. Biofilm production has been suggested to be important for GBS pathogenesis alongside many other elements, including phylogenetic lineage and virulence factors, such as pili and capsule type. A complete understanding of the confluence of these components, however, is lacking. To identify associations between biofilm phenotype, pilus profile and lineage, 293 strains from asymptomatic carriers, invasive disease cases, and bovine mastitis cases, were assessed for biofilm production using an in vitro assay. RESULTS Multilocus sequence type (ST) profile, pilus island profile, and isolate source were associated with biofilm production. Strains from invasive disease cases and/or belonging to the ST-17 and ST-19 lineages were significantly more likely to form weak biofilms, whereas strains producing strong biofilms were recovered more frequently from individuals with asymptomatic colonization. CONCLUSIONS These data suggest that biofilm production is a lineage-specific trait in GBS and may promote colonization of strains representing lineages other than STs 17 and 19. The findings herein also demonstrate that biofilms must be considered in the treatment of pregnant women, particularly for women with heavy GBS colonization.
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Affiliation(s)
- Robert E Parker
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
| | - Clare Laut
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
| | - Jennifer A Gaddy
- Tennessee Valley Healthcare System, Department of Veterans Affairs, Nashville, TN, USA.,Department of Medicine, Vanderbilt University, Nashville, TN, USA
| | - Ruth N Zadoks
- Institute for Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK.,Moredun Research Institute, Penicuik, UK
| | - H Dele Davies
- University of Nebraska Medical School, Omaha, NE, USA
| | - Shannon D Manning
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA.
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