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Goh KGK, Desai D, Thapa R, Prince D, Acharya D, Sullivan MJ, Ulett GC. An opportunistic pathogen under stress: how Group B Streptococcus responds to cytotoxic reactive species and conditions of metal ion imbalance to survive. FEMS Microbiol Rev 2024; 48:fuae009. [PMID: 38678005 PMCID: PMC11098048 DOI: 10.1093/femsre/fuae009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 03/26/2024] [Accepted: 04/16/2024] [Indexed: 04/29/2024] Open
Abstract
Group B Streptococcus (GBS; also known as Streptococcus agalactiae) is an opportunistic bacterial pathogen that causes sepsis, meningitis, pneumonia, and skin and soft tissue infections in neonates and healthy or immunocompromised adults. GBS is well-adapted to survive in humans due to a plethora of virulence mechanisms that afford responses to support bacterial survival in dynamic host environments. These mechanisms and responses include counteraction of cell death from exposure to excess metal ions that can cause mismetallation and cytotoxicity, and strategies to combat molecules such as reactive oxygen and nitrogen species that are generated as part of innate host defence. Cytotoxicity from reactive molecules can stem from damage to proteins, DNA, and membrane lipids, potentially leading to bacterial cell death inside phagocytic cells or within extracellular spaces within the host. Deciphering the ways in which GBS responds to the stress of cytotoxic reactive molecules within the host will benefit the development of novel therapeutic and preventative strategies to manage the burden of GBS disease. This review summarizes knowledge of GBS carriage in humans and the mechanisms used by the bacteria to circumvent killing by these important elements of host immune defence: oxidative stress, nitrosative stress, and stress from metal ion intoxication/mismetallation.
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Affiliation(s)
- Kelvin G K Goh
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Devika Desai
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Ruby Thapa
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Darren Prince
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Dhruba Acharya
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
| | - Matthew J Sullivan
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
| | - Glen C Ulett
- School of Pharmacy and Medical Sciences, and Menzies Health Institute Queensland, Griffith University, Parklands Drive, Southport, Gold Coast Campus, QLD 4222, Australia
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2
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Mancin E, Maltecca C, Huang YJ, Mantovani R, Tiezzi F. A first characterization of the microbiota-resilience link in swine. MICROBIOME 2024; 12:53. [PMID: 38486255 PMCID: PMC10941389 DOI: 10.1186/s40168-024-01771-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Accepted: 01/30/2024] [Indexed: 03/17/2024]
Abstract
BACKGROUND The gut microbiome plays a crucial role in understanding complex biological mechanisms, including host resilience to stressors. Investigating the microbiota-resilience link in animals and plants holds relevance in addressing challenges like adaptation of agricultural species to a warming environment. This study aims to characterize the microbiota-resilience connection in swine. As resilience is not directly observable, we estimated it using four distinct indicators based on daily feed consumption variability, assuming animals with greater intake variation may face challenges in maintaining stable physiological status. These indicators were analyzed both as linear and categorical variables. In our first set of analyses, we explored the microbiota-resilience link using PERMANOVA, α-diversity analysis, and discriminant analysis. Additionally, we quantified the ratio of estimated microbiota variance to total phenotypic variance (microbiability). Finally, we conducted a Partial Least Squares-Discriminant Analysis (PLS-DA) to assess the classification performance of the microbiota with indicators expressed in classes. RESULTS This study offers four key insights. Firstly, among all indicators, two effectively captured resilience. Secondly, our analyses revealed robust relationship between microbial composition and resilience in terms of both composition and richness. We found decreased α-diversity in less-resilient animals, while specific amplicon sequence variants (ASVs) and KEGG pathways associated with inflammatory responses were negatively linked to resilience. Thirdly, considering resilience indicators in classes, we observed significant differences in microbial composition primarily in animals with lower resilience. Lastly, our study indicates that gut microbial composition can serve as a reliable biomarker for distinguishing individuals with lower resilience. CONCLUSION Our comprehensive analyses have highlighted the host-microbiota and resilience connection, contributing valuable insights to the existing scientific knowledge. The practical implications of PLS-DA and microbiability results are noteworthy. PLS-DA suggests that host-microbiota interactions could be utilized as biomarkers for monitoring resilience. Furthermore, the microbiability findings show that leveraging host-microbiota insights may improve the identification of resilient animals, supporting their adaptive capacity in response to changing environmental conditions. These practical implications offer promising avenues for enhancing animal well-being and adaptation strategies in the context of environmental challenges faced by livestock populations. Video Abstract.
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Affiliation(s)
- Enrico Mancin
- Department of Agronomy, Animals and Environment, (DAFNAE), Food, Natural Resources, University of Padova, Viale del Università 14, 35020, Legnaro (Padova), Italy
| | - Christian Maltecca
- Department of Animal Science, North Carolina State University, Raleigh, NC, 27695, USA
- Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence, Piazzale delle Cascine 18, 50144, Firenze, Italy
| | - Yi Jian Huang
- Smithfield Premium Genetics, Rose Hill, NC, 28458, USA
| | - Roberto Mantovani
- Department of Agronomy, Animals and Environment, (DAFNAE), Food, Natural Resources, University of Padova, Viale del Università 14, 35020, Legnaro (Padova), Italy
| | - Francesco Tiezzi
- Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence, Piazzale delle Cascine 18, 50144, Firenze, Italy.
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Cao Q, Dong Y, Guo C, Ji S, Nie M, Liu G, Wan X, Lu C, Liu Y. luxS contributes to intramacrophage survival of Streptococcus agalactiae by positively affecting the expression of fruRKI operon. Vet Res 2023; 54:83. [PMID: 37759250 PMCID: PMC10536698 DOI: 10.1186/s13567-023-01210-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 08/25/2023] [Indexed: 09/29/2023] Open
Abstract
The LuxS quorum sensing system is a widespread system employed by many bacteria for cell-to-cell communication. The luxS gene has been demonstrated to play a crucial role in intramacrophage survival of piscine Streptococcus agalactiae, but the underlying mechanism remains largely unknown. In this study, transcriptome analysis, followed by the luxS gene deletion and subsequent functional studies, confirmed that impaired bacterial survival inside macrophages due to the inactivation of luxS was associated with reduced transcription of the fruRKI operon, encoding the fructose-specific phosphotransferase system. Further, luxS was determined not to enhance the transcription of fruRKI operon by binding its promoter, but to upregulate the expression of this operon via affecting the binding ability of catabolite control protein A (CcpA) to the catabolite responsive element (cre) in the promoter of fruRKI. Collectively, our study identifies a novel and previously unappreciated role for luxS in bacterial intracellular survival, which may give a more thorough understanding of the immune evasion mechanism in S. agalactiae.
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Affiliation(s)
- Qing Cao
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Yuhao Dong
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Changming Guo
- Jiangsu Agri-Animal Husbandry Vocational College, Taizhou, Jiangsu, China
| | - Shuting Ji
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Meng Nie
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Guangjin Liu
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Xihe Wan
- Institute of Oceanology and Marine Fisheries, Nantong, China
| | - Chengping Lu
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Yongjie Liu
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China.
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Mejia ME, Robertson CM, Patras KA. Interspecies Interactions within the Host: the Social Network of Group B Streptococcus. Infect Immun 2023; 91:e0044022. [PMID: 36975791 PMCID: PMC10112235 DOI: 10.1128/iai.00440-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023] Open
Abstract
Group B Streptococcus (GBS) is a pervasive neonatal pathogen accounting for a combined half a million deaths and stillbirths annually. The most common source of fetal or neonatal GBS exposure is the maternal microbiota. GBS asymptomatically colonizes the gastrointestinal and vaginal mucosa of 1 in 5 individuals globally, although its precise role in these niches is not well understood. To prevent vertical transmission, broad-spectrum antibiotics are administered to GBS-positive mothers during labor in many countries. Although antibiotics have significantly reduced GBS early-onset neonatal disease, there are several unintended consequences, including an altered neonatal microbiota and increased risk for other microbial infections. Additionally, the incidence of late-onset GBS neonatal disease remains unaffected and has sparked an emerging hypothesis that GBS-microbe interactions in developing neonatal gut microbiota may be directly involved in this disease process. This review summarizes our current understanding of GBS interactions with other resident microbes at the mucosal surface from multiple angles, including clinical association studies, agriculture and aquaculture observations, and experimental animal model systems. We also include a comprehensive review of in vitro findings of GBS interactions with other bacterial and fungal microbes, both commensal and pathogenic, along with newly established animal models of GBS vaginal colonization and in utero or neonatal infection. Finally, we provide a perspective on emerging areas of research and current strategies to design microbe-targeting prebiotic or probiotic therapeutic intervention strategies to prevent GBS disease in vulnerable populations.
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Affiliation(s)
- Marlyd E. Mejia
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | - Clare M. Robertson
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | - Kathryn A. Patras
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
- Alkek Center for Metagenomics and Microbiome Research, Baylor College of Medicine, Houston, Texas, USA
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5
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Roux AE, Robert S, Bastat M, Rosinski-Chupin I, Rong V, Holbert S, Mereghetti L, Camiade E. The Role of Regulator Catabolite Control Protein A (CcpA) in Streptococcus agalactiae Physiology and Stress Response. Microbiol Spectr 2022; 10:e0208022. [PMID: 36264242 PMCID: PMC9784791 DOI: 10.1128/spectrum.02080-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 09/21/2022] [Indexed: 01/06/2023] Open
Abstract
Streptococcus agalactiae is a leading cause of infections in neonates. This opportunistic pathogen colonizes the vagina, where it has to cope with acidic pH and hydrogen peroxide produced by lactobacilli. Thus, in the host, this bacterium possesses numerous adaptation mechanisms in which the pleiotropic regulators play a major role. The transcriptional regulator CcpA (catabolite control protein A) has previously been shown to be the major regulator involved in carbon catabolite repression in Gram-positive bacteria but is also involved in other functions. By transcriptomic analysis, we characterized the CcpA-dependent gene regulation in S. agalactiae. Approximately 13.5% of the genome of S. agalactiae depends on CcpA for regulation and comprises genes involved in sugar uptake and fermentation, confirming the role of CcpA in carbon metabolism. We confirmed by electrophoretic mobility shift assays (EMSAs) that the DNA binding site called cis-acting catabolite responsive element (cre) determined for other streptococci was effective in S. agalactiae. We also showed that CcpA is of capital importance for survival under acidic and oxidative stresses and is implicated in macrophage survival by regulating several genes putatively or already described as involved in stress response. Among them, we focused our study on SAK_1689, which codes a putative UspA protein. We demonstrated that SAK_1689, highly downregulated by CcpA, is overexpressed under oxidative stress conditions, this overexpression being harmful for the bacterium in a ΔccpA mutant. IMPORTANCE Streptococcus agalactiae is a major cause of disease burden leading to morbidity and mortality in neonates worldwide. Deciphering its adaptation mechanisms is essential to understand how this bacterium manages to colonize its host. Here, we determined the regulon of the pleiotropic regulator CcpA in S. agalactiae. Our findings reveal that CcpA is not only involved in carbon catabolite repression, but is also important for acidic and oxidative stress resistance and survival in macrophages.
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Affiliation(s)
| | | | | | - Isabelle Rosinski-Chupin
- Unité Écologie et Évolution de la Résistance aux Antibiotiques, CNRS UMR3525, Institut Pasteur, Paris, France
| | | | | | - Laurent Mereghetti
- ISP, Université de Tours, INRAE, Tours, France
- CHRU Tours, Service de Bactériologie-Virologie-Hygiène, Tours, France
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Streptococcus agalactiae npx Is Required for Survival in Human Placental Macrophages and Full Virulence in a Model of Ascending Vaginal Infection during Pregnancy. mBio 2022; 13:e0287022. [PMID: 36409087 PMCID: PMC9765263 DOI: 10.1128/mbio.02870-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Streptococcus agalactiae, also known as group B Streptococcus (GBS), is a Gram-positive encapsulated bacterium that colonizes the gastrointestinal tract of 30 to 50% of humans. GBS causes invasive infection during pregnancy that can lead to chorioamnionitis, funisitis, preterm prelabor rupture of membranes (PPROM), preterm birth, neonatal sepsis, and maternal and fetal demise. Upon infecting the host, GBS encounters sentinel innate immune cells, such as macrophages, within reproductive tissues. Once phagocytosed by macrophages, GBS upregulates the expression of the gene npx, which encodes an NADH peroxidase. GBS mutants with an npx deletion (Δnpx) are exquisitely sensitive to reactive oxygen stress. Furthermore, we have shown that npx is required for GBS survival in both THP-1 and placental macrophages. In an in vivo murine model of ascending GBS vaginal infection during pregnancy, npx is required for invading reproductive tissues and is critical for inducing disease progression, including PPROM and preterm birth. Reproductive tissue cytokine production was also significantly diminished in Δnpx mutant-infected animals compared to that in animals infected with wild-type (WT) GBS. Complementation in trans reversed this phenotype, indicating that npx is critical for GBS survival and the initiation of proinflammatory signaling in the gravid host. IMPORTANCE This study sheds new light on the way that group B Streptococcus (GBS) defends itself against oxidative stress in the infected host. The enzyme encoded by the GBS gene npx is an NADH peroxidase that, our study reveals, provides defense against macrophage-derived reactive oxygen stress and facilitates infections of the uterus during pregnancy. This enzyme could represent a tractable target for future treatment strategies against invasive GBS infections.
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7
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Guevara MA, Francis JD, Lu J, Manning SD, Doster RS, Moore RE, Gaddy JA. Streptococcus agalactiae cadD Is Critical for Pathogenesis in the Invertebrate Galleria mellonella Model. ACS Infect Dis 2022; 8:2405-2412. [PMID: 36445344 PMCID: PMC10262471 DOI: 10.1021/acsinfecdis.2c00453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Group B Streptococcus (GBS) is a gram-positive bacterium that can cause invasive infections in immunocompromised, elderly, pregnant, or neonatal patients. The invertebrate model, Galleria mellonella, has emerged as an effective tool to study GBS-host interactions; specifically, those conserved within the innate arm of the immune system. We sought to determine the role of metal homeostasis functions in GBS infections of G. mellonella larvae and to validate this model as a tool to study GBS-host interactions. Our results indicate that wild-type GBS infects G. mellonella in a dose-dependent manner, replicates in the invertebrate host, induces larval melanization and larval killing. These results were significantly abrogated in cohorts of larvae infected with the isogenic cadD deletion mutant. Additionally, complementation restored GBS-dependent infection, bacterial burden, larval melanization, and killing to wild-type levels. Together, these results indicate that the G. mellonella model is a useful tool for studying GBS pathogenesis.
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Affiliation(s)
- Miriam A. Guevara
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, 37232, U.S.A
| | - Jamisha D. Francis
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, 37232, U.S.A
| | - Jacky Lu
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, 37232, U.S.A
| | - Shannon D. Manning
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, 48864, U.S.A
| | - Ryan S. Doster
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, 37232, U.S.A
| | - Rebecca E. Moore
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, 37232, U.S.A
| | - Jennifer A. Gaddy
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, 37232, U.S.A
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, 37232, U.S.A
- Tennessee Valley Healthcare Systems, Department of Veterans Affairs, Nashville, Tennessee, 37212, U.S.A
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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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Ma F, Yang S, Wang G, Zhou M, Zhang J, Deng B, Yin W, Wang H, Lu Y, Fan H. Effect of multiplicity of infection on the evasion of neutrophil killing by Streptococcus agalactiae isolated from clinical mastitis bovine. Vet Microbiol 2022; 270:109450. [PMID: 35580447 DOI: 10.1016/j.vetmic.2022.109450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 04/21/2022] [Accepted: 04/30/2022] [Indexed: 10/18/2022]
Abstract
Streptococcus agalactiae (S. agalactiae) causes intramammary infection in dairy cows. Increased neutrophils and a high bacterial load are important characteristics of bovine bacterial mastitis. We hypothesized that the multiplicity of infection (MOI) of S. agalactiae in bovine mastitis plays an important role in bacterial pathogenicity by modulating the neutrophil response to promote bacterial survival. Neutrophils from BALB/c mice were infected with the bovine mastitis isolate of S. agalactiae SAG-FX17 at various MOIs, and neutrophil responses were investigated. Infecting neutrophils with SAG-FX17 at an MOI of 1 induced reactive oxygen species (ROS) and neutrophil extracellular traps (NETs) formation. Bacteria at an MOI of 10 suppressed neutrophil responses, including ROS bursts, NET formation, and cell necrosis, which are conducive to bacterial multiplication within 30 min postinfection. In addition, neutrophils are destroyed by SAG-FX17 at an MOI of 100 or greater. This study identified the MOIs related to the ROS and NET suppression caused by SAG-FX17, and the findings suggested that interventions to decrease bacterial loads before the MOI of 10 could be necessary and effective to harness the power of innate immune response to eliminate pathogens.
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Affiliation(s)
- Fang Ma
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Shifang Yang
- College of Veterinary Medicine, Nanjing Agriculture University, Nanjing, China
| | - Guangyu Wang
- College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing, Jiangsu 210023, China
| | - Mingxu Zhou
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Jinqiu Zhang
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Bihua Deng
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Wenzhu Yin
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Haiyan Wang
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Yu Lu
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
| | - Hongjie Fan
- College of Veterinary Medicine, Nanjing Agriculture University, Nanjing, China.
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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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11
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Lu J, Francis JD, Guevara MA, Moore RE, Chambers SA, Doster RS, Eastman AJ, Rogers LM, Noble KN, Manning SD, Damo SM, Aronoff DM, Townsend SD, Gaddy JA. Antibacterial and Anti-biofilm Activity of the Human Breast Milk Glycoprotein Lactoferrin against Group B Streptococcus. Chembiochem 2021; 22:2124-2133. [PMID: 33755306 DOI: 10.1002/cbic.202100016] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/15/2021] [Indexed: 12/14/2022]
Abstract
Group B Streptococcus (GBS) is an encapsulated Gram-positive human pathogen that causes invasive infections in pregnant hosts and neonates, as well as immunocompromised individuals. Colonization of the human host requires the ability to adhere to mucosal surfaces and circumnavigate the nutritional challenges and antimicrobial defenses associated with the innate immune response. Biofilm formation is a critical process to facilitate GBS survival and establishment of a replicative niche in the vertebrate host. Previous work has shown that the host responds to GBS infection by producing the innate antimicrobial glycoprotein lactoferrin, which has been implicated in repressing bacterial growth and biofilm formation. Additionally, lactoferrin is highly abundant in human breast milk and could serve a protective role against invasive microbial pathogens. This study demonstrates that human breast milk lactoferrin has antimicrobial and anti-biofilm activity against GBS and inhibits its adherence to human gestational membranes. Together, these results indicate that human milk lactoferrin could be used as a prebiotic chemotherapeutic strategy to limit the impact of bacterial adherence and biofilm formation on GBS-associated disease outcomes.
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Affiliation(s)
- Jacky Lu
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center A2200 Medical Center North, 1161 21st Avenue South, Nashville, TN 37232, USA
| | - Jamisha D Francis
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center A2200 Medical Center North, 1161 21st Avenue South, Nashville, TN 37232, USA
| | - Miriam A Guevara
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center A2200 Medical Center North, 1161 21st Avenue South, Nashville, TN 37232, USA
| | - Rebecca E Moore
- Department of Chemistry, Vanderbilt University, Camille Dreyfus Teacher Scholar and a Fellow of the Alfred P. Sloan Foundation, 7330 Stevenson Center, Station B 351822, Nashville, TN 37235, USA
| | - Schuyler A Chambers
- Department of Chemistry, Vanderbilt University, Camille Dreyfus Teacher Scholar and a Fellow of the Alfred P. Sloan Foundation, 7330 Stevenson Center, Station B 351822, Nashville, TN 37235, USA
| | - Ryan S Doster
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Alison J Eastman
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Lisa M Rogers
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Kristen N Noble
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37212, USA
| | - Shannon D Manning
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
| | - Steven M Damo
- Department of Life and Physical Sciences, Fisk University, Nashville, TN 37208, USA.,Department of Biochemistry, Vanderbilt University, Nashville, TN 37232, USA.,Department of Structural Biology, Vanderbilt University, Nashville, TN, TN 37232, USA
| | - David M Aronoff
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center A2200 Medical Center North, 1161 21st Avenue South, Nashville, TN 37232, USA.,Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.,Department of Obstetrics and Gynecology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Steven D Townsend
- Department of Chemistry, Vanderbilt University, Camille Dreyfus Teacher Scholar and a Fellow of the Alfred P. Sloan Foundation, 7330 Stevenson Center, Station B 351822, Nashville, TN 37235, USA
| | - Jennifer A Gaddy
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center A2200 Medical Center North, 1161 21st Avenue South, Nashville, TN 37232, USA.,Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.,Tennessee Valley Healthcare Systems, Department of Veterans Affairs, Nashville, TN 37212, USA
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12
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Jusuf S, Dong PT, Hui J, Ulloa ER, Liu GY, Cheng JX. Granadaene Photobleaching Reduces the Virulence and Increases Antimicrobial Susceptibility of Streptococcus agalactiae. Photochem Photobiol 2021; 97:816-825. [PMID: 33502005 DOI: 10.1111/php.13389] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 01/20/2021] [Indexed: 12/14/2022]
Abstract
Streptococcus agalactiae, also known as Group B Streptococcus (GBS), is increasingly recognized as a major cause of soft tissue and invasive diseases in the elderly and diabetic populations. Antibiotics like penicillin are used with great frequency to treat these infections, although antimicrobial resistance is increasing among GBS strains and underlines a need for alternative methods not reliant on traditional antibiotics. GBS granadaene pigment is related to the hemolysin/cytolysin of GBS, which is critical for the pathogenesis of GBS diseases. Here, we show that photobleaching granadaene dampens the hemolytic activity of GBS. Furthermore, photobleaching of this antioxidant was found to increase GBS susceptibility to killing by reactive oxygen species like hydrogen peroxide. Treatment with light was also shown to affect GBS membrane permeability and contribute to increased susceptibility to the cell membrane-targeting antibiotic daptomycin. Overall, our study demonstrates dual effects of photobleaching on the virulence and antimicrobial susceptibility of GBS and suggests a novel approach for the treatment of GBS infection.
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Affiliation(s)
- Sebastian Jusuf
- Department of Biomedical Engineering, Boston University, Boston, MA
| | - Pu-Ting Dong
- Department of Chemistry, Boston University, Boston, MA
| | - Jie Hui
- Department of Electrical & Computer Engineering, Boston University, Boston, MA
| | - Erlinda R Ulloa
- Department of Pediatrics, University of California Irvine School of Medicine, Irvine, CA
| | - George Y Liu
- Division of Pediatric Infectious Diseases, University of California San Diego School of Medicine, La Jolla, CA
| | - Ji-Xin Cheng
- Department of Biomedical Engineering, Boston University, Boston, MA.,Department of Chemistry, Boston University, Boston, MA.,Department of Electrical & Computer Engineering, Boston University, Boston, MA.,Photonics Center, Boston University, Boston, MA
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13
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Pieranski M, Sitkiewicz I, Grinholc M. Increased photoinactivation stress tolerance of Streptococcus agalactiae upon consecutive sublethal phototreatments. Free Radic Biol Med 2020; 160:657-669. [PMID: 32916279 DOI: 10.1016/j.freeradbiomed.2020.09.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/24/2020] [Accepted: 09/02/2020] [Indexed: 02/08/2023]
Abstract
Streptococcus agalactiae (Group B Streptococcus, GBS) is a common commensal bacterium in adults but remains a leading source of invasive infections in newborns, pregnant women, and the elderly, and more recently, causes an increased incidence of invasive disease in nonpregnant adults. Reduced penicillin susceptibility and emerging resistance to non-β-lactams pose challenges for the development and implementation of novel, nonantimicrobial strategies to reduce the burden of GBS infections. Antimicrobial photodynamic inactivation (aPDI) via the production of singlet oxygen or other reactive oxygen species leads to the successful eradication of pathogenic bacteria, affecting numerous cellular targets of microbial pathogens and indicating a low risk of resistance development. Nevertheless, we have previously reported possible aPDI tolerance development upon repeated sublethal aPDI applications; thus, the current work was aimed at investigating whether aPDI tolerance could be observed for GBS and what mechanisms could cause it. To address this problem, 10 cycles of sublethal aPDI treatments employing rose bengal as a photosensitizer, were applied to the S. agalactiae ATCC 27956 reference strain and two clinical isolates (2306/02 and 2974/07, serotypes III and V, respectively). We demonstrated aPDI tolerance development and stability after 5 cycles of subculturing with no aPDI exposure. Though the treatment resulted in a stable phenotype, no increases in mutation rate or accumulated genetic alterations were observed (employing a RIF-, CIP-, STR-resistant mutant selection assay and cyl sequencing, respectively). qRT-PCR analysis demonstrated that 10 sublethal aPDI exposures led to increased expression of all tested major oxidative stress response elements; changes in sodA, ahpC, npx, cylE, tpx and recA expression indicate possible mechanisms of developed tolerance. Increased expression upon sublethal aPDI treatment was reported for all but two genes, namely, ahpC and cylE. aPDI targeting cylE was further supported by colony morphology changes induced with 10 cycles of aPDI (increased SCV population, increased hemolysis, increased numbers of dark- and unpigmented colonies). In oxidant killing assays, aPDI-tolerant strains demonstrated no increased tolerance to hypochlorite, superoxide (paraquat), singlet oxygen (new methylene blue) or oxidative stress induced by aPDI employing a structurally different photosensitizer, i.e., zinc phthalocyanine, indicating a lack of cross resistance. The results indicate that S. agalactiae may develop stable aPDI tolerance but not resistance when subjected to multiple sublethal phototreatments, and this risk should be considered significant when defining efficient anti-S. agalactiae aPDI protocols.
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Affiliation(s)
- Michal Pieranski
- Intercollegiate Faculty of Biotechnology, Laboratory of Molecular Diagnostics, University of Gdansk and Medical University of Gdansk, Abrahama 58, 80-307, Gdansk, Poland
| | - Izabela Sitkiewicz
- Department of Drug Biotechnology and Bioinformatics, National Medicines Institute, Chelmska 30/34, 00-725, Warszawa, Poland
| | - Mariusz Grinholc
- Intercollegiate Faculty of Biotechnology, Laboratory of Molecular Diagnostics, University of Gdansk and Medical University of Gdansk, Abrahama 58, 80-307, Gdansk, Poland.
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14
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Zhang T, Zhu J, Xu J, Shao H, Zhou R. Regulation of (p)ppGpp and Its Homologs on Environmental Adaptation, Survival, and Pathogenicity of Streptococci. Front Microbiol 2020; 11:1842. [PMID: 33101217 PMCID: PMC7545056 DOI: 10.3389/fmicb.2020.01842] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 07/14/2020] [Indexed: 11/13/2022] Open
Abstract
Most streptococci are commensals, pathogens, or opportunistic pathogens for humans and animals. Therefore, it is important for streptococci to adapt to the various challenging environments of the host during the processes of infection or colonization, as well as to in vitro conditions for transmission. Stringent response (SR) is a special class of adaptive response induced by the signal molecules (p)ppGpp, which regulate several physiological aspects, such as long-term persistence, virulence, biofilm formation, and quorum sensing in bacteria. To understand the roles of SR in streptococci, the current mini-review gives a general overview on: (1) (p)ppGpp synthetases in the genus of Streptococcus, (2) the effects of (p)ppGpp on the physiological phenotypes, persistence, and pathogenicity of streptococci, (3) the transcriptional regulation induced by (p)ppGpp in streptococci, and (4) the link between (p)ppGpp and another nutrient regulatory protein CodY in streptococci.
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Affiliation(s)
- Tengfei Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Institute of Animal and Veterinary Science, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Jiawen Zhu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Institute of Animal Sciences, Chengdu Academy of Agricultural and Forestry Sciences, Chengdu, China
| | - Jiajia Xu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Huabin Shao
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Institute of Animal and Veterinary Science, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Rui Zhou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,International Research Center for Animal Disease (Ministry of Science & Technology of China), Wuhan, China.,Cooperative Innovation Center of Sustainable Pig Production, Wuhan, China
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15
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Sánchez-Tarjuelo R, Cortegano I, Manosalva J, Rodríguez M, Ruíz C, Alía M, Prado MC, Cano EM, Ferrándiz MJ, de la Campa AG, Gaspar ML, de Andrés B. The TLR4-MyD88 Signaling Axis Regulates Lung Monocyte Differentiation Pathways in Response to Streptococcus pneumoniae. Front Immunol 2020; 11:2120. [PMID: 33042124 PMCID: PMC7525032 DOI: 10.3389/fimmu.2020.02120] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 08/05/2020] [Indexed: 12/20/2022] Open
Abstract
Streptococcus pneumoniae is the main cause of bacterial pneumonia, a condition that currently produces significant global morbidity and mortality. The initial immune response to this bacterium occurs when the innate system recognizes common motifs expressed by many pathogens, events driven by pattern recognition receptors like the Toll-like family receptors (TLRs). In this study, lung myeloid-cell populations responsible for the innate immune response (IIR) against S. pneumoniae, and their dependence on the TLR4-signaling axis, were analyzed in TLR4-/- and Myeloid-Differentiation factor-88 deficient (MyD88-/-) mice. Neutrophils and monocyte-derived cells were recruited in infected mice 3-days post-infection. Compared to wild-type mice, there was an increased bacterial load in both these deficient mouse strains and an altered IIR, although TLR4-/- mice were more susceptible to bacterial infection. These mice also developed fewer alveolar macrophages, weaker neutrophil infiltration, less Ly6Chigh monocyte differentiation and a disrupted classical and non-classical monocyte profile. The pro-inflammatory cytokine profile (CXCL1, TNF-α, IL-6, and IL-1β) was also severely affected by the lack of TLR4 and no induction of Th1 was observed in these mice. The respiratory burst (ROS production) after infection was profoundly dampened in TLR4-/- and MyD88-/- mice. These data demonstrate the complex dynamics of myeloid populations and a key role of the TLR4-signaling axis in the IIR to S. pneumoniae, which involves both the MyD88 and TRIF (Toll/IL-1R domain-containing adaptor-inducing IFN-β) dependent pathways.
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Affiliation(s)
| | - Isabel Cortegano
- Immunobiology Department, Carlos III Health Institute, Madrid, Spain
| | - Juliana Manosalva
- Immunobiology Department, Carlos III Health Institute, Madrid, Spain
| | | | - Carolina Ruíz
- Immunobiology Department, Carlos III Health Institute, Madrid, Spain
| | - Mario Alía
- Immunobiology Department, Carlos III Health Institute, Madrid, Spain
| | | | - Eva M. Cano
- Chronic Disease Programme, Carlos III Health Institute, Madrid, Spain
| | | | - Adela G. de la Campa
- Bacterial Genetics Department, Carlos III Health Institute, Madrid, Spain
- Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | | | - Belén de Andrés
- Immunobiology Department, Carlos III Health Institute, Madrid, Spain
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16
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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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17
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Liu T, Liu J, Liu J, Yang R, Lu X, He X, Shi W, Guo L. Interspecies Interactions Between Streptococcus Mutans and Streptococcus Agalactiae in vitro. Front Cell Infect Microbiol 2020; 10:344. [PMID: 32733820 PMCID: PMC7358462 DOI: 10.3389/fcimb.2020.00344] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 06/04/2020] [Indexed: 01/30/2023] Open
Abstract
Streptococcus mutans is an oral species closely associated with dental caries. As an early oral colonizer, S. mutans utilizes interspecies coaggregation to promote the colonization of subsequent species and affect polymicrobial pathogenesis. Previous studies have confirmed several adhering partner species of S. mutans, including Candida albicans and Fusobacterium nucleatum. In this study, we discovered new intergeneric co-adherence between S. mutans and the saliva isolate Streptococcus agalactiae (GBS-SI101). Research shows that GBS typically colonizes the human gastrointestinal and vaginal tracts. It is responsible for adverse pregnancy outcomes and life-threatening infections in neonates and immunocompromised people. Our results revealed that GtfB and GtfC of S. mutans, which contributed to extracellular polysaccharide synthesis, promoted coaggregation of S. mutans with GBS-SI101. In addition, oral streptococci, including Streptococcus sanguinis, Streptococcus gordonii and S. mutans, barely inhibited the growth of GBS-SI101. This study indicated that S. mutans could help GBS integrate into the Streptococcus-associated oral polymicrobial community and become a resident species in the oral cavity, increasing the risk of oral infections.
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Affiliation(s)
- Tingjun Liu
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Jia Liu
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Jianwei Liu
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Ruiqi Yang
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Xianjun Lu
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Xuesong He
- The Forsyth Institute, Cambridge, MA, United States
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, United States
| | - Wenyuan Shi
- The Forsyth Institute, Cambridge, MA, United States
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, United States
| | - Lihong Guo
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
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18
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Depardieu F, Bikard D. Gene silencing with CRISPRi in bacteria and optimization of dCas9 expression levels. Methods 2020; 172:61-75. [PMID: 31377338 DOI: 10.1016/j.ymeth.2019.07.024] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/25/2019] [Accepted: 07/29/2019] [Indexed: 12/15/2022] Open
Abstract
The catalytic null mutant of the Cas9 endonuclease from the bacterial CRISPR immune system, known as dCas9, can be guided by a small RNA to bind DNA sequences of interest and block gene transcription in a strategy known as CRISPRi. This powerful gene silencing method has already been used in a large number of species and in high throughput screens. Here we provide detailed design rules, methods and novel vectors to perform CRISPRi experiments in S. aureus and in E. coli, using the well characterized dCas9 protein from S. pyogenes. In particular, we describe a vector based on plasmid pC194 which is broadly used in Firmicutes, as well as a vector based on the very broad host-range rolling circle plasmid pLZ12, reported to replicate in both Firmicutes and Proteobacteria. A potential caveat of adapting dCas9 tools to various bacterial species is that dCas9 was shown to be toxic when expressed too strongly. We describe a method to optimize the expression level of dCas9 in order to avoid toxicity while ensuring strong on-target repression activity. We demonstrate this method by optimizing a pLZ12 based vector originally developed for S. aureus so that it can work in E. coli. This article should provide all the resources required to perform CRISPRi experiments in a broad range of bacterial species.
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Affiliation(s)
| | - David Bikard
- Groupe de Biologie de Synthèse, Institut Pasteur, Paris 75015, France.
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19
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Romero R, Gomez-Lopez N, Winters AD, Jung E, Shaman M, Bieda J, Panaitescu B, Pacora P, Erez O, Greenberg JM, Ahmad MM, Hsu CD, Theis KR. Evidence that intra-amniotic infections are often the result of an ascending invasion - a molecular microbiological study. J Perinat Med 2019; 47:915-931. [PMID: 31693497 PMCID: PMC7147941 DOI: 10.1515/jpm-2019-0297] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 08/18/2019] [Indexed: 12/15/2022]
Abstract
Background Microbial invasion of the amniotic cavity resulting in intra-amniotic infection is associated with obstetrical complications such as preterm labor with intact or ruptured membranes, cervical insufficiency, as well as clinical and histological chorioamnionitis. The most widely accepted pathway for intra-amniotic infection is the ascension of microorganisms from the lower genital tract. However, hematogenous dissemination of microorganisms from the oral cavity or intestine, retrograde seeding from the peritoneal cavity through the fallopian tubes, and introduction through invasive medical procedures have also been suggested as potential pathways for intra-amniotic infection. The primary reason that an ascending pathway is viewed as most common is that the microorganisms most often detected in the amniotic fluid are those that are typical inhabitants of the vagina. However, thus far, no studies have shown that microorganisms in the amniotic cavity are simultaneously present in the vagina of the woman from which they were isolated. The objective of the study was to determine the frequency with which microorganisms isolated from women with intra-amniotic infection are also present in the lower genital tract. Methods This was a cross-sectional study of women with intra-amniotic infection with intact membranes. Intra-amniotic infection was defined as a positive culture and elevated concentrations of interleukin-6 (IL-6) (>2.6 ng/mL) in amniotic fluid and/or acute histologic chorioamnionitis and funisitis. Microorganisms isolated from bacterial cultures of amniotic fluid were taxonomically identified through matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF) and 16S ribosomal RNA (rRNA) gene sequencing. Vaginal swabs were obtained at the time of amniocentesis for the identification of microorganisms in the lower genital tract. The overall bacterial profiles of amniotic fluids and vaginal swabs were characterized through 16S rRNA gene sequencing. The bacterial profiles of vaginal swabs were interrogated for the presence of bacteria cultured from amniotic fluid and for the presence of prominent (>1% average relative abundance) operational taxonomic units (OTUs) within the overall 16S rRNA gene bacterial profiles of amniotic fluid. Results (1) A total of 75% (6/8) of women had bacteria cultured from their amniotic fluid that are typical residents of the vaginal ecosystem. (2) A total of 62.5% (5/8) of women with bacteria cultured from their amniotic fluid also had these bacteria present in their vagina. (3) The microorganisms cultured from amniotic fluid and also detected in the vagina were Ureaplasma urealyticum, Escherichia coli, and Streptococcus agalactiae. (4) 16S rRNA gene sequencing revealed that the amniotic fluid of women with intra-amniotic infection had bacterial profiles dominated by Sneathia, Ureaplasma, Prevotella, Lactobacillus, Escherichia, Gardnerella, Peptostreptococcus, Peptoniphilus, and Streptococcus, many of which had not been cultured from the amniotic fluid samples. (5) Seventy percent (7/10) of the prominent (>1% average relative abundance) OTUs found in amniotic fluid were also prominent in the vagina. Conclusion The majority of women with intra-amniotic infection had bacteria cultured from their amniotic fluid that were typical vaginal commensals, and these bacteria were detected within the vagina at the time of amniocentesis. Molecular microbiological interrogation of amniotic fluid from women with intra-amniotic infection revealed that the bacterial profiles of amniotic fluid were largely consistent with those of the vagina. These findings indicate that ascension from the lower genital tract is the primary pathway for intra-amniotic infection.
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Affiliation(s)
- Roberto Romero
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, MD, and Detroit, MI, USA
- Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI, USA
- Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI, USA
- Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI, USA
- Detroit Medical Center, Detroit, MI, USA
- Department of Obstetrics and Gynecology, Florida International University, Miami, FL, USA
| | - Nardhy Gomez-Lopez
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, MD, and Detroit, MI, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
- Department of Biochemistry, Microbiology and Immunology, Wayne State University School of Medicine, Detroit, MI, USA
- Perinatal Research Initiative in Maternal, Perinatal and Child Health, Wayne State University School of Medicine, Detroit, MI, USA
| | - Andrew D. Winters
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, MD, and Detroit, MI, USA
- Department of Biochemistry, Microbiology and Immunology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Eunjung Jung
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, MD, and Detroit, MI, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Majid Shaman
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, MD, and Detroit, MI, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Janine Bieda
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, MD, and Detroit, MI, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Bogdan Panaitescu
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, MD, and Detroit, MI, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Percy Pacora
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, MD, and Detroit, MI, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Offer Erez
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, MD, and Detroit, MI, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
- Maternity Department “D,” Division of Obstetrics and Gynecology, Soroka University Medical Center School of Medicine, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel
| | - Jonathan M. Greenberg
- Department of Biochemistry, Microbiology and Immunology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Madison M. Ahmad
- Department of Biochemistry, Microbiology and Immunology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Chaur-Dong Hsu
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, MD, and Detroit, MI, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
- Perinatal Research Initiative in Maternal, Perinatal and Child Health, Wayne State University School of Medicine, Detroit, MI, USA
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Kevin R. Theis
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, MD, and Detroit, MI, USA
- Department of Biochemistry, Microbiology and Immunology, Wayne State University School of Medicine, Detroit, MI, USA
- Perinatal Research Initiative in Maternal, Perinatal and Child Health, Wayne State University School of Medicine, Detroit, MI, USA
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20
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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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21
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Le Guennec L, Coureuil M, Nassif X, Bourdoulous S. Strategies used by bacterial pathogens to cross the blood-brain barrier. Cell Microbiol 2019; 22:e13132. [PMID: 31658405 DOI: 10.1111/cmi.13132] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 10/11/2019] [Accepted: 10/13/2019] [Indexed: 12/15/2022]
Abstract
The skull, spine, meninges, and cellular barriers at the blood-brain and the blood-cerebrospinal fluid interfaces well protect the brain and meningeal spaces against microbial invasion. However, once in the bloodstream, a range of pathogenic bacteria is able to reach the brain and cause meningitis. Despite advances in antibacterial therapy, bacterial meningitis remains one of the most important infectious diseases worldwide. The most common causative bacteria in children and adults are Streptococcus pneumoniae and Neisseria meningitidis associated with high morbidity and mortality, while among neonates, most cases of bacterial meningitis are due to group B Streptococcus and Escherichia coli. Here we summarise our current knowledge on the strategies used by these bacterial pathogens to survive in the bloodstream, to colonise the brain vasculature and to cross the blood-brain barrier.
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Affiliation(s)
- Loic Le Guennec
- Inserm (Institut National de la Sante et de la Recherche Medicale), U1016, Institut Cochin, Paris, France.,CNRS (Centre National de la recherche Scientifique), UMR8104, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Mathieu Coureuil
- Inserm (Institut National de la Sante et de la Recherche Medicale), unité U1151, Institut-Necker-Enfants-Malades, Paris, France.,CNRS (Centre National de la recherche Scientifique), UMR 8253, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Faculté de médecine, Paris, France
| | - Xavier Nassif
- Inserm (Institut National de la Sante et de la Recherche Medicale), unité U1151, Institut-Necker-Enfants-Malades, Paris, France.,CNRS (Centre National de la recherche Scientifique), UMR 8253, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Faculté de médecine, Paris, France.,Assistance Publique - Hôpitaux de Paris, Hôpital Necker Enfants Malades, Paris, France
| | - Sandrine Bourdoulous
- Inserm (Institut National de la Sante et de la Recherche Medicale), U1016, Institut Cochin, Paris, France.,CNRS (Centre National de la recherche Scientifique), UMR8104, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
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22
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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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