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Li Z, Wang S, Li Q, Lin Q, Zhang C, Xi L, Cui Y, Dai Y, Yin S, Zhang Y, Zhang H. RNA-seq reveals the important role of transcriptional regulator DeoR1 in regulating Brucella abortus various pathways. J Proteomics 2024; 309:105297. [PMID: 39214508 DOI: 10.1016/j.jprot.2024.105297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 08/15/2024] [Accepted: 08/27/2024] [Indexed: 09/04/2024]
Abstract
Brucella spp. is an intracellular bacterium that uses its transcriptional regulator DeoR1 to promote intracellular transport and survival, but the molecular mechanism remains unknown. To analyze the role of DeoR1 in the virulence of B. abortus and the genes regulated by DeoR1, we created a A19ΔdeoR1 mutant of B. abortus A19 (A19). Virulence assay was performed using a murine macrophage cell line (RAW264.7) and mice. We observed that A19ΔdeoR1 mutant is attenuated in RAW264.7 cells and mice. We performed RNA-seq whole transcriptome analysis of A19ΔdeoR1 and A19 from infected RAW264.7 cells. A total of 135 differentially expressed genes were identified, including 100 up-regulated and 35 down-regulated genes. These differentially expressed genes were involved in amino acid synthesis and metabolism, energy production and conversion, stress proteins, chaperonin, hypothetical proteins and protein of unknown function, cell wall/membrane/envelope, intracellular transporting and secretion, and transcriptional regulator. Interestingly, genes involved in the intracellular trafficking and secretion were significantly down-regulated in A19ΔdeoR1. Furthermore, selected RNA-seq results were experimentally confirmed by qRT-PCR. Overall, these results deciphered differential phenomena associated with virulence in A19ΔdeoR1 and A19 from infected RAW264.7 cells, which provided important information for understanding the detailed role of DeoR1 in Brucella pathogenesis. SIGNIFICANCE: Transcriptional regulators are predominant bacterial signal transduction factors. The pathogenicity of Brucella is due to its ability to regulate the expression of virulence related genes. Transcriptional regulators are designed to regulate gene expression and enact an appropriate adaptive physiological response. Here, a total of 135 differentially expressed genes were identified in transcriptional regulator deoR1 mutant.
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Affiliation(s)
- Zhiqiang Li
- College of Biology and Food, Shangqiu Normal University, Shangqiu 476000, Henan Provence, China; College of Medical Technology, Shangqiu Medical College, Shangqiu 476005, Henan Provence, China
| | - Shuli Wang
- College of Biology and Food, Shangqiu Normal University, Shangqiu 476000, Henan Provence, China
| | - Qifeng Li
- TECON Biotechnology Co., Ltd, Urumqi 830011, Xinjiang Provence, China
| | - Qiuhui Lin
- College of Biology and Food, Shangqiu Normal University, Shangqiu 476000, Henan Provence, China
| | - Chunmei Zhang
- College of Biology and Food, Shangqiu Normal University, Shangqiu 476000, Henan Provence, China
| | - Li Xi
- College of Biology and Food, Shangqiu Normal University, Shangqiu 476000, Henan Provence, China
| | - Yanyan Cui
- College of Biology and Food, Shangqiu Normal University, Shangqiu 476000, Henan Provence, China
| | - Yawen Dai
- College of Biology and Food, Shangqiu Normal University, Shangqiu 476000, Henan Provence, China
| | - Shuanghong Yin
- College of Biology, Agriculture and Forestry, Tongren University, Tongren 554300, Guizhou Province, China
| | - Yu Zhang
- College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang Provence, China
| | - Hui Zhang
- College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang Provence, China.
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Poveda-Urkixo I, Mena-Bueno S, Ramírez GA, Zabalza-Baranguá A, Tsolis RM, Grilló MJ. Brucella melitensis Rev1Δwzm: Placental pathogenesis studies and safety in pregnant ewes. Vaccine 2024; 42:3710-3720. [PMID: 38755066 DOI: 10.1016/j.vaccine.2024.04.085] [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: 10/25/2023] [Revised: 01/20/2024] [Accepted: 04/27/2024] [Indexed: 05/18/2024]
Abstract
One of the main causes of human brucellosis is Brucella melitensis infecting small ruminants. To date, Rev1 is the only vaccine successfully used to control ovine and caprine brucellosis. However, it is pathogenic for pregnant animals, resulting in abortions and vaginal and milk shedding, as well as being infectious for humans. Therefore, there is an urgent need to develop an effective vaccine that is safer than Rev1. In efforts to further attenuate Rev1, we recently used wzm inactivation to generate a rough mutant (Rev1Δwzm) that retains a complete antigenic O-polysaccharide in the bacterial cytoplasm. The aim of the present study was to evaluate the placental pathogenicity of Rev1Δwzm in trophoblastic cells, throughout pregnancy in mice, and in ewes inoculated in different trimesters of pregnancy. This mutant was evaluated in comparison with the homologous 16MΔwzm derived from a virulent strain of B. melitensis and the naturally rough sheep pathogen B. ovis. Our results show that both wzm mutants triggered reduced cytotoxic, pro-apoptotic, and pro-inflammatory signaling in Bewo trophoblasts, as well as reduced relative expression of apoptosis genes. In mice, both wzm mutants produced infection but were rapidly cleared from the placenta, in which only Rev1Δwzm induced a low relative expression of pro-apoptotic and pro-inflammatory genes. In the 66 inoculated ewes, Rev1Δwzm was safe and immunogenic, displaying a transient serological interference in standard RBT but not CFT S-LPS tests; this serological response was minimized by conjunctival administration. In conclusion, these results support that B. melitensis Rev1Δwzm is a promising vaccine candidate for use in pregnant ewes and its efficacy against B. melitensis and B. ovis infections in sheep warrants further study.
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Affiliation(s)
- Irati Poveda-Urkixo
- Animal Health Department, Institute of Agrobiotechnology (IdAB; CSIC-Navarra Government), Avda. Pamplona 123, 31192 Mutilva, Navarra, Spain
| | - Sara Mena-Bueno
- Animal Health Department, Institute of Agrobiotechnology (IdAB; CSIC-Navarra Government), Avda. Pamplona 123, 31192 Mutilva, Navarra, Spain; Public University of Navarra (UPNA), Avda. de Pamplona 123, 31192 Mutilva, Spain
| | | | - Ana Zabalza-Baranguá
- Animal Health Department, Institute of Agrobiotechnology (IdAB; CSIC-Navarra Government), Avda. Pamplona 123, 31192 Mutilva, Navarra, Spain
| | - Renee M Tsolis
- Medical Microbiology and Immunology, University of California, Davis, 95616 USA
| | - María-Jesús Grilló
- Animal Health Department, Institute of Agrobiotechnology (IdAB; CSIC-Navarra Government), Avda. Pamplona 123, 31192 Mutilva, Navarra, Spain.
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3
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Li Z, Wang S, Han J, Yang G, Xi L, Zhang C, Cui Y, Yin S, Zhang Y, Zhang H. Insights into the effect of guanylate-binding protein 1 on the survival of Brucella intracellularly. Vet Microbiol 2024; 293:110089. [PMID: 38678845 DOI: 10.1016/j.vetmic.2024.110089] [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: 11/25/2023] [Revised: 04/05/2024] [Accepted: 04/10/2024] [Indexed: 05/01/2024]
Abstract
Brucellosis is a zoonotic disease that affects wild and domestic animals. It is caused by members of the bacterial genus Brucella. Guanylate-binding protein 1 (GBP1) is associated with microbial infections. However, the role of GBP1 during Brucella infection remains unclear. This investigation aimed to identify the association of GBP1 with brucellosis. Results showed that Brucella infection induced GBP1 upregulation in RAW 264.7 murine macrophages. Small interfering GBP1 targeting RNAs were utilized to explore how GBP1 regulates the survival of Brucella intracellularly. Results revealed that GBP1 knockdown promoted Brucella's survival ability, activated Nod-like receptor (NLR) containing a pyrin domain 3 (NLRP3) and absent in melanoma 2 (AIM2) inflammatory corpuscles, and induced pro-inflammatory cytokines IFN-γ and IL-1β. Furthermore, Brucella stimulated the expression of GBP1 in bone marrow-derived macrophages (BMDMs) and mice. During the inhibition of GBP1 in BMDMs, the intracellular growth of Brucella increased. In comparison, GBP1 downregulation enhanced the accumulation of Brucella-induced reactive oxygen species (ROS) in macrophages. Overall, the data indicate a significant role of GBP1 in regulating brucellosis and suggest the function underlying its suppressive effect on the survival and growth of Brucella intracellularly.
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Affiliation(s)
- Zhiqiang Li
- College of Biology and Food, Shangqiu Normal University, Shangqiu, Henan Provence 476000, China; School of Medical Technology, Shangqiu Medical College, Shangqiu, Henan Provence 476005, China
| | - Shuli Wang
- College of Biology and Food, Shangqiu Normal University, Shangqiu, Henan Provence 476000, China
| | - Jincheng Han
- College of Biology and Food, Shangqiu Normal University, Shangqiu, Henan Provence 476000, China
| | - Guangli Yang
- College of Biology and Food, Shangqiu Normal University, Shangqiu, Henan Provence 476000, China
| | - Li Xi
- College of Biology and Food, Shangqiu Normal University, Shangqiu, Henan Provence 476000, China
| | - Chunmei Zhang
- College of Biology and Food, Shangqiu Normal University, Shangqiu, Henan Provence 476000, China
| | - Yanyan Cui
- College of Biology and Food, Shangqiu Normal University, Shangqiu, Henan Provence 476000, China
| | - Shuanghong Yin
- College of Biology, Agriculture and Forestry, Tongren University, Tongren, Guizhou Province 554300, China
| | - Yu Zhang
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang Province 832003, China
| | - Hui Zhang
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang Province 832003, China.
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4
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Guo J, Deng X, Zhang Y, Song S, Zhao T, Zhu D, Cao S, Baryshnikov PI, Cao G, Blair HT, Chen C, Gu X, Liu L, Zhang H. The Flagellar Transcriptional Regulator FtcR Controls Brucella melitensis 16M Biofilm Formation via a betI-Mediated Pathway in Response to Hyperosmotic Stress. Int J Mol Sci 2022; 23:ijms23179905. [PMID: 36077302 PMCID: PMC9456535 DOI: 10.3390/ijms23179905] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 08/26/2022] [Accepted: 08/27/2022] [Indexed: 11/16/2022] Open
Abstract
The expression of flagellar proteins in Brucella species likely evolved through genetic transference from other microorganisms, and contributed to virulence, adaptability, and biofilm formation. Despite significant progress in defining the molecular mechanisms behind flagellar gene expression, the genetic program controlling biofilm formation remains unclear. The flagellar transcriptional factor (FtcR) is a master regulator of the flagellar system’s expression, and is critical for B. melitensis 16M’s flagellar biogenesis and virulence. Here, we demonstrate that FtcR mediates biofilm formation under hyperosmotic stress. Chromatin immunoprecipitation with next-generation sequencing for FtcR and RNA sequencing of ftcR-mutant and wild-type strains revealed a core set of FtcR target genes. We identified a novel FtcR-binding site in the promoter region of the osmotic-stress-response regulator gene betI, which is important for the survival of B. melitensis 16M under hyperosmotic stress. Strikingly, this site autoregulates its expression to benefit biofilm bacteria’s survival under hyperosmotic stress. Moreover, biofilm reduction in ftcR mutants is independent of the flagellar target gene fliF. Collectively, our study provides new insights into the extent and functionality of flagellar-related transcriptional networks in biofilm formation, and presents phenotypic and evolutionary adaptations that alter the regulation of B. melitensis 16M to confer increased tolerance to hyperosmotic stress.
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Affiliation(s)
- Jia Guo
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
| | - Xingmei Deng
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
| | - Yu Zhang
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
| | - Shengnan Song
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
| | - Tianyi Zhao
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
| | - Dexin Zhu
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
| | - Shuzhu Cao
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
| | - Peter Ivanovic Baryshnikov
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
- College of Veterinary, Altai State Agricultural University, 656000 Barnaul, Russia
| | - Gang Cao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430000, China
| | - Hugh T. Blair
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
- International Sheep Research Center, School of Agriculture and Environment, Massey University, Palmerston North 4442, New Zealand
| | - Chuangfu Chen
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
| | - Xinli Gu
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
| | - Liangbo Liu
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
- Correspondence: (L.L.); (H.Z.); Tel.: +86-0993-2057971 (L.L. & H.Z.)
| | - Hui Zhang
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi 832003, China
- Correspondence: (L.L.); (H.Z.); Tel.: +86-0993-2057971 (L.L. & H.Z.)
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5
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Guo J, Zhu J, Zhao T, Sun Z, Song S, Zhang Y, Zhu D, Cao S, Deng X, Chai Y, Sun Y, Maratbek S, Chen C, Liu L, Zhang H. Survival characteristics and transcriptome profiling reveal the adaptive response of the Brucella melitensis 16M biofilm to osmotic stress. Front Microbiol 2022; 13:968592. [PMID: 36060772 PMCID: PMC9428795 DOI: 10.3389/fmicb.2022.968592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 07/28/2022] [Indexed: 11/13/2022] Open
Abstract
Brucella can inhabit hostile environments, including osmotic stress. How Brucella responds collectively to osmotic stress is largely unexplored, particularly in spatially structured communities such as a biofilm. To gain insight into this growth mode, we set out to characterize the Brucella melitensis 16M biofilm, describe its phenotype, and carry out a comparative transcriptomic analysis between biofilms under osmotic stress and control conditions. We determined that the bacteria challenged with 1.5 M NaCl had a reduced ability to aggregate and form clumps and develop a biofilm; however, the salt stress promoted the release of the outer membrane vesicles from the biofilm. Together with the genotypical response to osmotic stress, we identified 279 differentially expressed genes in B. melitensis 16M grown under osmotic conditions compared with control conditions; 69 genes were upregulated and 210 downregulated. Under osmotic stress, the main changed genes of biofilm were predicted to be involved in flagellar assembly, cell envelope, translation, small RNA regulation, transport and binding proteins, and energy metabolism. In addition, the ABC transporter was enriched in the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. We highlight 12 essential ABC transporter genes associated with a bacterial response to osmotic stress at the biofilm stage, including one specific locus, BME_RS12880, mediating betaine accumulation in biofilms to eliminate osmotic stress. The current study results can help researchers gain insights into B. melitensis 16M biofilm adaptation to osmotic stress and provide information for developing intervention strategies to control Brucella.
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Affiliation(s)
- Jia Guo
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Jiale Zhu
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Tianyi Zhao
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Zhihua Sun
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Shengnan Song
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Yu Zhang
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Dexin Zhu
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Shuzhu Cao
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Xingmei Deng
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Yingjin Chai
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Yongxue Sun
- Collaborative Innovation Center for Sheep Healthy Farming and Zoonotic Disease Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Suleimenov Maratbek
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
- College of Veterinary, National Agricultural University of Kazakhstan, Nur-Sultan, Kazakhstan
| | - Chuangfu Chen
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Liangbo Liu
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
- *Correspondence: Liangbo Liu,
| | - Hui Zhang
- State International Joint Research Center for Animal Health Breeding, College of Animal Science and Technology, Shihezi University, Shihezi, China
- Hui Zhang,
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Shi C, Wang S, Han J, Xi L, Li M, Li Z, Zhang H. Functional insights into Brucella transcriptional regulator ArsR. Microb Pathog 2022; 168:105557. [PMID: 35623565 DOI: 10.1016/j.micpath.2022.105557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 03/20/2022] [Accepted: 04/24/2022] [Indexed: 11/15/2022]
Abstract
ArsR-family transcriptional factors regulates diverse physiological functions necessary for Brucella adaptation to environmental changes. However, whether the ArsR-family transcriptional regulator are related to virulence, and the precise determination of ArsR direct targets in Brucella are still unknown. Therefore, we created a 2308ΔArsR6 mutant of B. abortus 2308 (S2308). Virulence assay was performed using a murine macrophage cell line (RAW 264.7). We performed chromatin immunoprecipitation of ArsR6 followed by next-generation sequencing (ChIP-seq). We also selected the target gene pobA (BAB2_0600), and created the mutant (2308ΔpobA). The survival capability of 2308ΔpobA strain in RAW 264.7 was detected and the levels of tumor necrosis factor-α (TNF-α), interferon-gamma (IFN-γ), interleukin-12 (IL-12) and interleukin-18 (IL-18) were also measured. The results showed that 2308ΔArsR6 reduced survival capability in RAW 264.7. We detected 40 intergenic ChIP-seq peaks of ArsR6 binding distributed across the Brucella genome. 2308ΔpobA was significantly reduced survival capability in RAW 264.7. After the macrophages were infected with 2308ΔpobA, the levels of TNF-α, IFN-γ, IL-12 and IL-18 were decreased and were significantly lower than that for the S2308-infected group, indicating that the 2308ΔpobA could reduce the secretion of inflammatory cytokines. Taken together, the research provided new insights into the functionality of ArsR6 and great significance to clarify the function of ArsR6.
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Affiliation(s)
- Chuanxin Shi
- College of Biology and Food, Shangqiu Normal University, Shangqiu, 476000, Henan Provence, China
| | - Shuli Wang
- College of Biology and Food, Shangqiu Normal University, Shangqiu, 476000, Henan Provence, China
| | - Jincheng Han
- College of Biology and Food, Shangqiu Normal University, Shangqiu, 476000, Henan Provence, China
| | - Li Xi
- College of Biology and Food, Shangqiu Normal University, Shangqiu, 476000, Henan Provence, China
| | - Min Li
- College of Animal Science and Technology, Shihezi University, Shihezi, 832003, Xinjiang Provence, China
| | - Zhiqiang Li
- College of Biology and Food, Shangqiu Normal University, Shangqiu, 476000, Henan Provence, China.
| | - Hui Zhang
- College of Animal Science and Technology, Shihezi University, Shihezi, 832003, Xinjiang Provence, China.
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7
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Li Y, Sun W, Wang Q, Yu Y, Wan Y, Zhou K, Guo R, Han X, Chen Z, Fang W, Jiang W. The GntR-like transcriptional regulator HutC involved in motility, biofilm-forming ability, and virulence in Vibrio parahaemolyticus. Microb Pathog 2022; 167:105546. [DOI: 10.1016/j.micpath.2022.105546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 06/12/2021] [Accepted: 04/15/2022] [Indexed: 12/19/2022]
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Dammann AN, Chamby AB, Catomeris AJ, Davidson KM, Tettelin H, van Pijkeren JP, Gopalakrishna KP, Keith MF, Elder JL, Ratner AJ, Hooven TA. Genome-Wide fitness analysis of group B Streptococcus in human amniotic fluid reveals a transcription factor that controls multiple virulence traits. PLoS Pathog 2021; 17:e1009116. [PMID: 33684178 PMCID: PMC7971860 DOI: 10.1371/journal.ppat.1009116] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 03/18/2021] [Accepted: 02/18/2021] [Indexed: 02/06/2023] Open
Abstract
Streptococcus agalactiae (group B Streptococcus; GBS) remains a dominant cause of serious neonatal infections. One aspect of GBS that renders it particularly virulent during the perinatal period is its ability to invade the chorioamniotic membranes and persist in amniotic fluid, which is nutritionally deplete and rich in fetal immunologic factors such as antimicrobial peptides. We used next-generation sequencing of transposon-genome junctions (Tn-seq) to identify five GBS genes that promote survival in the presence of human amniotic fluid. We confirmed our Tn-seq findings using a novel CRISPR inhibition (CRISPRi) gene expression knockdown system. This analysis showed that one gene, which encodes a GntR-class transcription factor that we named MrvR, conferred a significant fitness benefit to GBS in amniotic fluid. We generated an isogenic targeted deletion of the mrvR gene, which had a growth defect in amniotic fluid relative to the wild type parent strain. The mrvR deletion strain also showed a significant biofilm defect in vitro. Subsequent in vivo studies showed that while the mutant was able to cause persistent murine vaginal colonization, pregnant mice colonized with the mrvR deletion strain did not develop preterm labor despite consistent GBS invasion of the uterus and the fetoplacental units. In contrast, pregnant mice colonized with wild type GBS consistently deliver prematurely. In a sepsis model the mrvR deletion strain showed significantly decreased lethality. In order to better understand the mechanism by which this newly identified transcription factor controls GBS virulence, we performed RNA-seq on wild type and mrvR deletion GBS strains, which revealed that the transcription factor affects expression of a wide range of genes across the GBS chromosome. Nucleotide biosynthesis and salvage pathways were highly represented among the set of differentially expressed genes, suggesting that MrvR may be involved in regulating nucleotide availability. Group B Streptococcus (GBS) is a species of Gram-positive bacteria that often colonizes the healthy adult intestinal and reproductive tracts without causing serious symptoms. During pregnancy, however, GBS can invade the pregnant uterus, where it can cause infection of the placenta, fetal membranes, and fetus—a condition known as chorioamnionitis. Chorioamnionitis is associated with serious adverse pregnancy outcomes, including stillbirth, preterm labor, and severe infection of the newborn. GBS can survive in human amniotic fluid, which is low in bacterial nutrients and contains immune molecules that limit microbial persistence, and this ability likely contributes to GBS chorioamnionitis. This study is focused on a single GBS gene that encodes a genetic regulator we called MrvR, which we show is important for GBS resistance to human amniotic fluid. Using a series of genetic techniques combined with animal models of GBS colonization and infection, we show that MrvR also plays a key role in allowing GBS to invade the bloodstream and trigger the inflammatory responses that lead to preterm labor and stillbirth. The study concludes with a survey of other GBS genes whose activity is regulated by MrvR, which seems to be an important contributor to GBS virulence.
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Affiliation(s)
- Allison N. Dammann
- Department of Pediatrics, New York University School of Medicine, New York, New York, United States of America
| | - Anna B. Chamby
- University of Vermont Larner College of Medicine, Burlington, Vermont, United States of America
| | - Andrew J. Catomeris
- Georgetown University School of Medicine, Washington, District of Columbia, United States of America
| | - Kyle M. Davidson
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Hervé Tettelin
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Jan-Peter van Pijkeren
- Department of Food Science, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Kathyayini P. Gopalakrishna
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Mary F. Keith
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Jordan L. Elder
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Adam J. Ratner
- Department of Pediatrics, New York University School of Medicine, New York, New York, United States of America
- Department of Microbiology, New York University, New York, New York, United States of America
| | - Thomas A. Hooven
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Richard King Mellon Institute for Pediatric Research, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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9
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Roop RM, Barton IS, Hopersberger D, Martin DW. Uncovering the Hidden Credentials of Brucella Virulence. Microbiol Mol Biol Rev 2021; 85:e00021-19. [PMID: 33568459 PMCID: PMC8549849 DOI: 10.1128/mmbr.00021-19] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Bacteria in the genus Brucella are important human and veterinary pathogens. The abortion and infertility they cause in food animals produce economic hardships in areas where the disease has not been controlled, and human brucellosis is one of the world's most common zoonoses. Brucella strains have also been isolated from wildlife, but we know much less about the pathobiology and epidemiology of these infections than we do about brucellosis in domestic animals. The brucellae maintain predominantly an intracellular lifestyle in their mammalian hosts, and their ability to subvert the host immune response and survive and replicate in macrophages and placental trophoblasts underlies their success as pathogens. We are just beginning to understand how these bacteria evolved from a progenitor alphaproteobacterium with an environmental niche and diverged to become highly host-adapted and host-specific pathogens. Two important virulence determinants played critical roles in this evolution: (i) a type IV secretion system that secretes effector molecules into the host cell cytoplasm that direct the intracellular trafficking of the brucellae and modulate host immune responses and (ii) a lipopolysaccharide moiety which poorly stimulates host inflammatory responses. This review highlights what we presently know about how these and other virulence determinants contribute to Brucella pathogenesis. Gaining a better understanding of how the brucellae produce disease will provide us with information that can be used to design better strategies for preventing brucellosis in animals and for preventing and treating this disease in humans.
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Affiliation(s)
- R Martin Roop
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Ian S Barton
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Dariel Hopersberger
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Daniel W Martin
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
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10
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Deng X, Li M, Liu L, Zhang J, Zhang Y, Guo J, Zhao T, Cao S, Li Z, Zhang H. Functional analysis of Bucella reveals transcriptional regulation of MarR. Microb Pathog 2020; 144:104201. [PMID: 32325238 DOI: 10.1016/j.micpath.2020.104201] [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: 01/28/2020] [Revised: 04/07/2020] [Accepted: 04/08/2020] [Indexed: 12/15/2022]
Abstract
Brucellosis is a zoonotic infectious disease caused by Brucella infection. MarR-family transcription factors are closely related to diverse physiological functions necessary for many pathogens adaptation to environmental changes. However, whether the MarR-family transcription factors are involved in virulence, mediated inflammatory responses and regulated virulence gene expression in the intracellular pathogen Brucella are still unknown. Therefore, we created a 2308ΔMarR6 mutant of B. abortus 2308 (S2308). Virulence and inflammatory cytokines assays were performed using a murine macrophage cell line (RAW 264.7). We also performed chromatin immunoprecipitation of MarR6 followed by next-generation sequencing (ChIP-seq). The results showed that 2308ΔMarR6 was significantly reduced survival capability in RAW 264.7. After the macrophages were infected with 2308ΔMarR6, the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-12 (IL-12), interferon-gamma (IFN-γ) and macrophage chemoattractant protein-1 (MCP-1) were decreased and were significantly lower than that for the S2308-infected group, indicating that the 2308ΔMarR6 mutant could reduce the secretion of inflammatory cytokines. Furthermore, we detected 122 intergenic ChIP-seq peaks of MarR6 binding distributed across the Brucella genome. Taken together, the research has recorded valuable data about MarR6. Our findings are of great significance in elucidating the function of MarR6.
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Affiliation(s)
- Xingmei Deng
- College of Animal Science and Technology, Shihezi University, Shihezi, 832003, Xinjiang Province, China
| | - Min Li
- College of Animal Science and Technology, Shihezi University, Shihezi, 832003, Xinjiang Province, China
| | - Liangbo Liu
- College of Animal Science and Technology, Shihezi University, Shihezi, 832003, Xinjiang Province, China
| | - Jing Zhang
- College of Animal Science and Technology, Shihezi University, Shihezi, 832003, Xinjiang Province, China
| | - Yu Zhang
- College of Animal Science and Technology, Shihezi University, Shihezi, 832003, Xinjiang Province, China
| | - Jia Guo
- College of Animal Science and Technology, Shihezi University, Shihezi, 832003, Xinjiang Province, China
| | - Tianyi Zhao
- College of Animal Science and Technology, Shihezi University, Shihezi, 832003, Xinjiang Province, China
| | - Shuzhu Cao
- College of Animal Science and Technology, Shihezi University, Shihezi, 832003, Xinjiang Province, China
| | - Zhiqiang Li
- College of Biology and Food, Shangqiu Normal University, Shangqiu, 476000, Henan Province, China.
| | - Hui Zhang
- College of Animal Science and Technology, Shihezi University, Shihezi, 832003, Xinjiang Province, China.
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11
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Li Z, Li M, Zhang H, Wang S, Xi L, Zhang X, Yi J, Zhang H. ChIP-seq analysis of Brucella
reveals transcriptional regulation of GntR. J Basic Microbiol 2019; 60:149-157. [DOI: 10.1002/jobm.201900458] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 10/11/2019] [Accepted: 10/30/2019] [Indexed: 12/28/2022]
Affiliation(s)
- Zhiqiang Li
- College of Biology and Food; Shangqiu Normal University; Shangqiu China
| | - Min Li
- College of Animal Science and Technology; Shihezi University; Shihezi China
| | - Hui Zhang
- College of Animal Science and Technology; Shihezi University; Shihezi China
| | - Shuli Wang
- College of Biology and Food; Shangqiu Normal University; Shangqiu China
| | - Li Xi
- College of Biology and Food; Shangqiu Normal University; Shangqiu China
| | - Xiaogen Zhang
- College of Biology and Food; Shangqiu Normal University; Shangqiu China
| | - Jihan Yi
- College of Animal Science and Technology; Shihezi University; Shihezi China
| | - Huan Zhang
- College of Animal Science and Technology; Shihezi University; Shihezi China
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12
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Zhou D, Zhi FJ, Qi MZ, Bai FR, Zhang G, Li JM, Liu H, Chen HT, Lin PF, Tang KQ, Liu W, Jin YP, Wang AH. Brucella induces unfolded protein response and inflammatory response via GntR in alveolar macrophages. Oncotarget 2017; 9:5184-5196. [PMID: 29435171 PMCID: PMC5797042 DOI: 10.18632/oncotarget.23706] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 12/04/2017] [Indexed: 01/18/2023] Open
Abstract
Brucella is an intracellular bacterium that causes the zoonosis brucellosis worldwide. Alveolar macrophages (AM) constitute the main cell target of inhaled Brucella. Brucella thwarts immune surveillance and evokes endoplasmic reticulum (ER) stress to replicate in macrophages via virulence factors. The GntR regulators family was concentrated as an important virulence factor in controlling virulence and intracellular survival of Brucella. However, the detailed underlying mechanism for the host-pathogen interaction is poorly understood. In this study the BSS2_II0438 mutant (ΔGntR) was constructed. The type IV secretion system (T4SS) virulence factor genes (VirB2, VirB6, and VirB8) were down-expression in ΔGntR. ΔGntR could infect and proliferate to high titers in GAMs without a significant difference compared with the parental strain. ΔGntR infection increased the expression of ER stress marker genes GRP78, ATF6, and PERK in the early stages of its intracellular cycle but decreased the expression of these genes in the late stages. ΔGntR increased greatly the number of Brucella CFUs in the inactive ER stress state in GAMs. Meanwhile, ΔGntR infection increased the levels of IFN-γ, IL-1β, and TNF-α, indicating ΔGntR could induce the secretion of inflammatory but not anti-inflammatory cytokines IL-10. Taken together, our results clarified the role of the GntR in B. suis. S2 virulence expression and elucidated that GntR is potentially involved in the signaling pathway of the Brucella-induced UPR and inflammatory response in GAMs.
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Affiliation(s)
- Dong Zhou
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Fei-Jie Zhi
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Mao-Zhen Qi
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Fu-Rong Bai
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Guangdong Zhang
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Jun-Mei Li
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Huan Liu
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Hua-Tao Chen
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Peng-Fei Lin
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Ke-Qiong Tang
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Wei Liu
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Ya-Ping Jin
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Ai-Hua Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
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13
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Li ZQ, Zhang JL, Xi L, Yang GL, Wang SL, Zhang XG, Zhang JB, Zhang H. Deletion of the transcriptional regulator GntR down regulated the expression of Genes Related to Virulence and Conferred Protection against Wild-Type Brucella Challenge in BALB/c Mice. Mol Immunol 2017; 92:99-105. [PMID: 29055858 DOI: 10.1016/j.molimm.2017.10.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Revised: 09/29/2017] [Accepted: 10/15/2017] [Indexed: 01/03/2023]
Abstract
Brucellosis, which is caused by Brucella spp., is a zoonotic infectious disease that can cause great hazard to public health and safety. The virulence of Brucella is essential for survive and multiply in host macrophages. GntR is a transcriptional regulator in Brucella that is required for virulence in macrophages and mice, and involved in resistance to stress responses. To determine the expression levels of target genes of GntR, we detected the expression levels of the GntR target genes in Brucella infected BALB/c mice. The results showed that several genes related to virulence, including omp25, virB1, vjbR, dnaK, htrA and hfq, were regulated by GntR during infection in BALB/c mice. Moreover, the 2308ΔgntR mutant induced high protective immunity in BALB/c mice challenge with B. abortus 2308 (S2308), and elicited an anti-Brucella-specific immunoglobulin G (IgG) response and induced the secretion of gamma interferon (IFN-γ) and interleukin-4 (IL-4). All together, these results indicated that gntR promoted the virulence of Brucella. The 2308ΔgntR was significantly attenuated in macrophages and mice and induced protective immune response during infection, suggested that 2308ΔgntR mutant is an attractive candidate for the design of a live attenuated vaccine against Brucella.
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Affiliation(s)
- Zhi-Qiang Li
- School of Biotechnology and Food, Shangqiu Normal University, Shangqiu 476000, Henan Province, China
| | - Jin-Liang Zhang
- School of Biotechnology and Food, Shangqiu Normal University, Shangqiu 476000, Henan Province, China
| | - Li Xi
- School of Biotechnology and Food, Shangqiu Normal University, Shangqiu 476000, Henan Province, China
| | - Guang-Li Yang
- School of Biotechnology and Food, Shangqiu Normal University, Shangqiu 476000, Henan Province, China
| | - Shu-Li Wang
- School of Biotechnology and Food, Shangqiu Normal University, Shangqiu 476000, Henan Province, China
| | - Xiao-Gen Zhang
- School of Biotechnology and Food, Shangqiu Normal University, Shangqiu 476000, Henan Province, China
| | - Jun-Bo Zhang
- College of Biology, Agriculture and Forestry, Tongren University, Tongren 554300, Guizhou Province, China
| | - Hui Zhang
- College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang Province, China.
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