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Yang L, Wu Z, Ma TY, Zeng H, Chen M, Zhang YA, Zhou Y. Identification of ClpB, a molecular chaperone involved in the stress tolerance and virulence of Streptococcus agalactiae. Vet Res 2024; 55:60. [PMID: 38750480 PMCID: PMC11094935 DOI: 10.1186/s13567-024-01318-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Accepted: 03/06/2024] [Indexed: 05/19/2024] Open
Abstract
Bacterial ClpB is an ATP-dependent disaggregate that belongs to the Hsp100/Clp family and facilitates bacterial survival under hostile environmental conditions. Streptococcus agalactiae, which is regarded as the major bacterial pathogen of farmed Nile tilapia (Oreochromis niloticus), is known to cause high mortality and large economic losses. Here, we report a ClpB homologue of S. agalactiae and explore its functionality. S. agalactiae with a clpB deletion mutant (∆clpB) exhibited defective tolerance against heat and acidic stress, without affecting growth or morphology under optimal conditions. Moreover, the ΔclpB mutant exhibited reduced intracellular survival in RAW264.7 cells, diminished adherence to the brain cells of tilapia, increased sensitivity to leukocytes from the head kidney of tilapia and whole blood killing, and reduced mortality and bacterial loads in a tilapia infection assay. Furthermore, the reduced virulence of the ∆clpB mutant was investigated by transcriptome analysis, which revealed that deletion of clpB altered the expression levels of multiple genes that contribute to the stress response as well as certain metabolic pathways. Collectively, our findings demonstrated that ClpB, a molecular chaperone, plays critical roles in heat and acid stress resistance and virulence in S. agalactiae. This finding provides an enhanced understanding of the functionality of this ClpB homologue in gram-positive bacteria and the survival strategy of S. agalactiae against immune clearance during infection.
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Affiliation(s)
- Lan Yang
- National Key Laboratory of Agricultural Microbiology; Hubei Hongshan Laboratory; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education; Shenzhen Institute of Nutrition and Health, College of Fisheries, Huazhong Agricultural University, Wuhan, 430000, China
| | - Zhihao Wu
- National Key Laboratory of Agricultural Microbiology; Hubei Hongshan Laboratory; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education; Shenzhen Institute of Nutrition and Health, College of Fisheries, Huazhong Agricultural University, Wuhan, 430000, China
| | - Tian-Yu Ma
- National Key Laboratory of Agricultural Microbiology; Hubei Hongshan Laboratory; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education; Shenzhen Institute of Nutrition and Health, College of Fisheries, Huazhong Agricultural University, Wuhan, 430000, China
| | - Hui Zeng
- National Key Laboratory of Agricultural Microbiology; Hubei Hongshan Laboratory; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education; Shenzhen Institute of Nutrition and Health, College of Fisheries, Huazhong Agricultural University, Wuhan, 430000, China
| | - Ming Chen
- National Key Laboratory of Agricultural Microbiology; Hubei Hongshan Laboratory; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education; Shenzhen Institute of Nutrition and Health, College of Fisheries, Huazhong Agricultural University, Wuhan, 430000, China
| | - Yong-An Zhang
- National Key Laboratory of Agricultural Microbiology; Hubei Hongshan Laboratory; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education; Shenzhen Institute of Nutrition and Health, College of Fisheries, Huazhong Agricultural University, Wuhan, 430000, China.
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510000, China.
| | - Yang Zhou
- National Key Laboratory of Agricultural Microbiology; Hubei Hongshan Laboratory; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education; Shenzhen Institute of Nutrition and Health, College of Fisheries, Huazhong Agricultural University, Wuhan, 430000, China.
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510000, China.
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture,, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China.
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The role of uspE in virulence and biofilm formation by Histophilus somni. Vet Microbiol 2021; 263:109267. [PMID: 34739965 DOI: 10.1016/j.vetmic.2021.109267] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 10/20/2021] [Indexed: 01/18/2023]
Abstract
UspE is a global regulator in Escherichia coli. To study the function of Histophilus somni uspE, strain 2336::TnuspE was identified from a bank of mutants generated with EZ::Tn5™<KAN-2> Tnp Transposome™ that were biofilm deficient. The 2336::TnuspE mutant was highly attenuated in mice, the electrophoretic profile of its lipooligosaccharide (LOS) indicated the LOS was truncated, and the mutant was significantly more serum-sensitive compared to the wildtype strain. In addition to forming a deficient biofilm, exopolysaccharide (EPS) production was also compromised, but the electrophoretic profile of outer membrane proteins was not altered. RNA sequence analysis revealed that the transcription levels of some stress response chaperones, transport proteins, and a large number of ribosomal protein genes in 2336::TnuspE were significantly differentially regulated compared to strain 2336. Therefore, uspE may differentially function in direct and indirect expression of H. somni genes, but its attenuation may be linked to poor biofilm formation and rapid clearance of the bacteria resulting from a compromised LOS structure. Our results support that uspE is a global stress regulatory gene in H. somni.
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Hsp100 Molecular Chaperone ClpB and Its Role in Virulence of Bacterial Pathogens. Int J Mol Sci 2021; 22:ijms22105319. [PMID: 34070174 PMCID: PMC8158500 DOI: 10.3390/ijms22105319] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/14/2021] [Accepted: 05/15/2021] [Indexed: 01/05/2023] Open
Abstract
This review focuses on the molecular chaperone ClpB that belongs to the Hsp100/Clp subfamily of the AAA+ ATPases and its biological function in selected bacterial pathogens, causing a variety of human infectious diseases, including zoonoses. It has been established that ClpB disaggregates and reactivates aggregated cellular proteins. It has been postulated that ClpB’s protein disaggregation activity supports the survival of pathogenic bacteria under host-induced stresses (e.g., high temperature and oxidative stress), which allows them to rapidly adapt to the human host and establish infection. Interestingly, ClpB may also perform other functions in pathogenic bacteria, which are required for their virulence. Since ClpB is not found in human cells, this chaperone emerges as an attractive target for novel antimicrobial therapies in combating bacterial infections.
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Alam A, Bröms JE, Kumar R, Sjöstedt A. The Role of ClpB in Bacterial Stress Responses and Virulence. Front Mol Biosci 2021; 8:668910. [PMID: 33968993 PMCID: PMC8100447 DOI: 10.3389/fmolb.2021.668910] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 04/06/2021] [Indexed: 02/04/2023] Open
Abstract
Bacterial survival within a mammalian host is contingent upon sensing environmental perturbations and initiating an appropriate counter-response. To achieve this, sophisticated molecular machineries are used, where bacterial chaperone systems play key roles. The chaperones are a prerequisite for bacterial survival during normal physiological conditions as well as under stressful situations, e.g., infection or inflammation. Specific stress factors include, but are not limited to, high temperature, osmolarity, pH, reactive oxidative species, or bactericidal molecules. ClpB, a member of class 1 AAA+ proteins, is a key chaperone that via its disaggregase activity plays a crucial role for bacterial survival under various forms of stress, in particular heat shock. Recently, it has been reported that ClpB also regulates secretion of bacterial effector molecules related to type VI secretion systems. In this review, the roles of ClpB in stress responses and the mechanisms by which it promotes survival of pathogenic bacteria are discussed.
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Affiliation(s)
- Athar Alam
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Department of Clinical Microbiology, Umeå University, Umeå, Sweden
| | - Jeanette E Bröms
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Department of Clinical Microbiology, Umeå University, Umeå, Sweden
| | - Rajender Kumar
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Department of Clinical Microbiology, Umeå University, Umeå, Sweden
| | - Anders Sjöstedt
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Department of Clinical Microbiology, Umeå University, Umeå, Sweden
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Tripathi P, Singh LK, Kumari S, Hakiem OR, Batra JK. ClpB is an essential stress regulator of Mycobacterium tuberculosis and endows survival advantage to dormant bacilli. Int J Med Microbiol 2020; 310:151402. [PMID: 32014406 DOI: 10.1016/j.ijmm.2020.151402] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 12/03/2019] [Accepted: 01/20/2020] [Indexed: 12/13/2022] Open
Abstract
The ability to tolerate multiple host derived stresses, resist eradication and persist within the infected individuals is central to the pathogenicity of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB). Mycobacterial survival is contingent upon sensing environmental perturbations and initiating a fitting response to counter them. Therefore, understanding of molecular mechanisms underlying stress tolerance and sensing in Mtb is critical for devising strategies for TB control. Our study aims to delineate the role of ClpB, a heat shock protein of Hsp100 family, in the general stress response and persistence mechanisms of Mtb. We demonstrate that Mtb requires ClpB to survive under stressful conditions. Additionally, we show that ClpB is necessary for the bacteria to persist in latency-like conditions such as prolonged hypoxia and nutrient-starvation. The disruption of ClpB results in aberrant cellular morphology, impaired biofilm formation and reduced infectivity of Mtb ex vivo. Our study also reports an alternative role of ClpB as a chaperokine which elicits inflammatory response in host. We conclude that ClpB is essential for Mtb to survive within macrophages, and plays a crucial part in the maintenance of dormant Mtb bacilli in latent state. The absence of ClpB in human genome makes it an attractive choice as drug target for TB.
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Affiliation(s)
- Prajna Tripathi
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Lalit K Singh
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Sujata Kumari
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Owais R Hakiem
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Janendra K Batra
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India; Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India.
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Romero-Lastra P, Sánchez MC, Llama-Palacios A, Figuero E, Herrera D, Sanz M. Gene expression of Porphyromonas gingivalis ATCC 33277 when growing in an in vitro multispecies biofilm. PLoS One 2019; 14:e0221234. [PMID: 31437202 PMCID: PMC6706054 DOI: 10.1371/journal.pone.0221234] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 08/01/2019] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND AND OBJECTIVE Porphyromonas gingivalis, an oral microorganism residing in the subgingival biofilm, may exert diverse pathogenicity depending on the presence of specific virulence factors, but its gene expression has not been completely established. This investigation aims to compare the transcriptomic profile of this pathogen when growing within an in vitro multispecies biofilm or in a planktonic state. MATERIALS AND METHODS P. gingivalis ATCC 33277 was grown in anaerobiosis within multi-well culture plates at 37°C under two conditions: (a) planktonic samples (no hydroxyapatite discs) or (b) within a multispecies-biofilm containing Streptococcus oralis, Actinomyces naeslundii, Veillonella parvula, Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans deposited on hydroxyapatite discs. Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM) combined with Fluorescence In Situ Hybridization (FISH) were used to verify the formation of the biofilm and the presence of P. gingivalis. Total RNA was extracted from both the multispecies biofilm and planktonic samples, then purified and, with the use of a microarray, its differential gene expression was analyzed. A linear model was used for determining the differentially expressed genes using a filtering criterion of two-fold change (up or down) and a significance p-value of <0.05. Differential expression was confirmed by Reverse Transcription-quantitative Polymerase Chain Reaction (RT-qPCR). RESULTS SEM verified the development of the multispecies biofilm and FISH confirmed the incorporation of P. gingivalis. The microarray demonstrated that, when growing within the multispecies biofilm, 19.1% of P. gingivalis genes were significantly and differentially expressed (165 genes were up-regulated and 200 down-regulated), compared with planktonic growth. These genes were mainly involved in functions related to the oxidative stress, cell envelope, transposons and metabolism. The results of the microarray were confirmed by RT-qPCR. CONCLUSION Significant transcriptional changes occurred in P. gingivalis when growing in a multispecies biofilm compared to planktonic state.
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Affiliation(s)
- Patricia Romero-Lastra
- Laboratory of Dental Research, Faculty of Odontology, Complutense University of Madrid, Madrid, Spain
| | - María C. Sánchez
- Laboratory of Dental Research, Faculty of Odontology, Complutense University of Madrid, Madrid, Spain
- ETEP Research Group, Faculty of Odontology, Complutense University of Madrid, Madrid, Spain
| | - Arancha Llama-Palacios
- Laboratory of Dental Research, Faculty of Odontology, Complutense University of Madrid, Madrid, Spain
- ETEP Research Group, Faculty of Odontology, Complutense University of Madrid, Madrid, Spain
| | - Elena Figuero
- ETEP Research Group, Faculty of Odontology, Complutense University of Madrid, Madrid, Spain
- * E-mail:
| | - David Herrera
- ETEP Research Group, Faculty of Odontology, Complutense University of Madrid, Madrid, Spain
| | - Mariano Sanz
- ETEP Research Group, Faculty of Odontology, Complutense University of Madrid, Madrid, Spain
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Mendez KN, Hoare A, Soto C, Bugueño I, Olivera M, Meneses C, Pérez-Donoso JM, Castro-Nallar E, Bravo D. Variability in Genomic and Virulent Properties of Porphyromonas gingivalis Strains Isolated From Healthy and Severe Chronic Periodontitis Individuals. Front Cell Infect Microbiol 2019; 9:246. [PMID: 31355151 PMCID: PMC6635597 DOI: 10.3389/fcimb.2019.00246] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 06/24/2019] [Indexed: 12/14/2022] Open
Abstract
Porphyromonas gingivalis has been extensively associated with both the onset and progression of periodontitis. We previously isolated and characterized two P. gingivalis strains, one from a patient exhibiting severe chronic periodontitis (CP3) and another from a periodontally healthy individual (H3). We previously showed that CP3 and H3 exhibit differences in virulence since H3 showed a lower resistance to cationic peptides compared with CP3, and a lower ability to induce proliferation in gingival epithelial cells. Here, we aimed to determine whether differences in virulence between these two strains are associated with the presence or absence of specific genes encoding virulence factors. We sequenced the whole genomes of both P. gingivalis CP3 and H3 and conducted a comparative analysis regarding P. gingivalis virulence genetic determinants. To do so, we performed a homology search of predicted protein sequences in CP3 and H3 genomes against the most characterized virulence genes for P. gingivalis available in the literature. In addition, we performed a genomic comparison of CP3 and H3 with all the 62 genomes of P. gingivalis found in NCBI's RefSeq database. This approach allowed us to determine the evolutionary relationships of CP3 and H3 with other virulent and avirulent strains; and additionally, to detect variability in presence/absence of virulence genes among P. gingivalis genomes. Our results show genetic variability in the hemagglutinin genes. While CP3 possesses one copy of hagA and two of hagC, H3 has no hagA and only one copy of hagC. Experimentally, this finding is related to lower in vitro hemmaglutination ability of H3 compared to CP3. Moreover, while CP3 encodes a gene for a major fimbrium subunit FimA type 4 (CP3_00160), H3 possess a FimA type 1 (H3_01400). Such genetic differences are in agreement with both lower biofilm formation ability and less intracellular invasion to oral epithelial cells exhibited by H3, compared with the virulent strain CP3. Therefore, here we provide new results on the genome sequences, comparative genomics analyses, and phenotypic analyses of two P. gingivalis strains. The genomics comparison of these two strains with the other 62 genomes included in the analysis provided relevant results regarding genetic determinants and their association with P. gingivalis virulence.
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Affiliation(s)
- Katterinne N Mendez
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile
| | - Anilei Hoare
- Laboratorio de Microbiología Oral, Facultad de Odontología, Universidad de Chile, Santiago, Chile
| | - Cristopher Soto
- Laboratorio de Microbiología Oral, Facultad de Odontología, Universidad de Chile, Santiago, Chile
| | - Isaac Bugueño
- Laboratorio de Microbiología Oral, Facultad de Odontología, Universidad de Chile, Santiago, Chile
| | - Marcela Olivera
- Laboratorio de Microbiología Oral, Facultad de Odontología, Universidad de Chile, Santiago, Chile
| | - Claudio Meneses
- Centro de Biotecnología Vegetal, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile.,FONDAP Center for Genome Regulation, Santiago, Chile
| | - Jose Manuel Pérez-Donoso
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile
| | - Eduardo Castro-Nallar
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile
| | - Denisse Bravo
- Laboratorio de Microbiología Oral, Facultad de Odontología, Universidad de Chile, Santiago, Chile
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Stand-alone ClpG disaggregase confers superior heat tolerance to bacteria. Proc Natl Acad Sci U S A 2017; 115:E273-E282. [PMID: 29263094 DOI: 10.1073/pnas.1712051115] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
AAA+ disaggregases solubilize aggregated proteins and confer heat tolerance to cells. Their disaggregation activities crucially depend on partner proteins, which target the AAA+ disaggregases to protein aggregates while concurrently stimulating their ATPase activities. Here, we report on two potent ClpG disaggregase homologs acquired through horizontal gene transfer by the species Pseudomonas aeruginosa and subsequently abundant P. aeruginosa clone C. ClpG exhibits high, stand-alone disaggregation potential without involving any partner cooperation. Specific molecular features, including high basal ATPase activity, a unique aggregate binding domain, and almost exclusive expression in stationary phase distinguish ClpG from other AAA+ disaggregases. Consequently, ClpG largely contributes to heat tolerance of P. aeruginosa primarily in stationary phase and boosts heat resistance 100-fold when expressed in Escherichia coli This qualifies ClpG as a potential persistence and virulence factor in P. aeruginosa.
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Francisella noatunensis subspecies noatunensis clpB deletion mutant impairs development of francisellosis in a zebrafish model. Vaccine 2017; 35:7264-7272. [PMID: 29153776 DOI: 10.1016/j.vaccine.2017.11.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 11/01/2017] [Accepted: 11/06/2017] [Indexed: 12/14/2022]
Abstract
BACKGROUND Francisella noatunensis ssp. noatunensis (F.n.n.) is the causative agent of francisellosis in Atlantic cod and constitutes one of the main challenges for future aquaculture on this species. A facultative intracellular bacterium like F.n.n. exert an immunologic challenge against which live attenuated vaccines in general are most effective. Thus, we constructed a deletion in the F.n.n. clpB gene as ΔclpB mutants are among the most promising vaccine candidates in human pathogenic Francisella. PURPOSE Characterization of F.n.n. ΔclpB using primary Atlantic cod head kidney leukocytes, the zebrafish embryo and adult zebrafish model with focus on potential attenuation, relevant immune responses and immunogenic potential. MAIN RESULTS Interleukin 1 beta transcription in Atlantic cod leukocytes was significantly elevated from 24 to 96 h post infection with F.n.n. ΔclpB compared to F.n.n. wild-type (wt). Growth attenuation of the deletion mutant in zebrafish embryos was observed by fluorescence microscopy and confirmed by genome quantification by qPCR. In the immunization experiment, adult zebrafish were immunized with 7 × 106 CFU of F.n.n. ΔclpB before challenge four weeks later with 6 × 108 CFU of F.n.n. wt. One day after challenge, immunized zebrafish responded with significantly lower interleukin 8 levels compared to the non-immunized control. Immunized fish were protected against the acute mortality observed in non-immunized zebrafish after challenge and bacterial genomes quantified by qPCR were reduced to a minimum 28 days post challenge, indicating protective immunity stimulated by F.n.n. ΔclpB. CONCLUSION Deletion mutation of clpB in F.n.n. causes in vitro and in vivo attenuation and elicits a protective immune response in adult zebrafish against a lethal dose of F.n.n. wt. Taken together, the results presented increases the knowledge on protective immune responses against F.n.n.
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Xu X, Tong T, Yang X, Pan Y, Lin L, Li C. Differences in survival, virulence and biofilm formation between sialidase-deficient and W83 wild-type Porphyromonas gingivalis strains under stressful environmental conditions. BMC Microbiol 2017; 17:178. [PMID: 28821225 PMCID: PMC5563019 DOI: 10.1186/s12866-017-1087-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 08/09/2017] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Porphyromonas gingivalis is a major causative pathogen of chronic periodontitis. Within the inflammatory microenvironment, there exists extreme pH values, elevated temperatures and oxidative stress. Pathogens adapt to these stressful environmental conditions by regulating the transcription of virulence genes, modifying themselves with macromolecules and by aggregating and entering into a biofilm growth phase. Our previous study showed that the P. gingivalis sialidase can help cells obtain sialic acid from the environment, which is used to modify macromolecules on the surface of P. gingivalis cells. In this study, we compared the survival, virulence factors and biofilm formation of a sialidase-deficient strain (ΔPG0352) and the wild-type P. gingivalis W83 strain under various pH values, temperatures and oxidative stress conditions to identify the roles of sialidase in the adaptation of P. gingivalis to stressful conditions. RESULTS Compared to the growth of the P. gingivalis W83 strain, the growth of the △PG0352 was more inhibited by oxidative stress (0.25 and 0.5 mM H2O2) and exhibited greater cell structure damage when treated with H2O2 as assessed by transmission electron microscopy. Both Lys-gingipain (Kgp) and Arg-gingipain (Rgp) activities were lower in the ΔPG0352 than those in the P. gingivalis W83 strain under all the assayed culture conditions. The lipopolysaccharide (LPS) activity of the W83 strain was higher than that of the ΔPG0352 under acidic conditions (pH 5.0), but no differences between the strains were observed under other conditions. Compared to the biofilms formed by P. gingivalis W83, those formed by the ΔPG0352 were decreased and discontinuous under acidic, alkaline and oxidative stress conditions. CONCLUSION Compared to the P. gingivalis W83 strain, the survival, virulence and biofilm formation of the ΔPG0352 were decreased under stressful environmental conditions.
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Affiliation(s)
- Xiaoyu Xu
- Department of Periodontics, School of Stomatology, China Medical University, No.117 Nanjing North Street, Heping District, Shenyang, Liaoning China
| | - Tong Tong
- Department of Periodontics, School of Stomatology, China Medical University, No.117 Nanjing North Street, Heping District, Shenyang, Liaoning China
- Department of Stomatology, Anshan Shuangshan Hospital, Anshan, Liaoning China
| | - Xue Yang
- Shenyang Medical College, Shenyang, Liaoning China
| | - Yaping Pan
- Department of Periodontics, School of Stomatology, China Medical University, No.117 Nanjing North Street, Heping District, Shenyang, Liaoning China
| | - Li Lin
- Department of Periodontics, School of Stomatology, China Medical University, No.117 Nanjing North Street, Heping District, Shenyang, Liaoning China
| | - Chen Li
- Department of Periodontics, School of Stomatology, China Medical University, No.117 Nanjing North Street, Heping District, Shenyang, Liaoning China
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11
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Connolly E, Millhouse E, Doyle R, Culshaw S, Ramage G, Moran GP. The Porphyromonas gingivalis hemagglutinins HagB and HagC are major mediators of adhesion and biofilm formation. Mol Oral Microbiol 2016; 32:35-47. [PMID: 28051836 DOI: 10.1111/omi.12151] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/16/2015] [Indexed: 11/28/2022]
Abstract
Porphyromonas gingivalis is a bacterium associated with chronic periodontitis that possesses a family of genes encoding hemagglutinins required for heme acquisition. In this study we generated ΔhagB and ΔhagC mutants in strain W83 and demonstrate that both hagB and hagC are required for adherence to oral epithelial cells. Unexpectedly, a double ΔhagB/ΔhagC mutant had less severe adherence defects than either of the single mutants, but was found to exhibit increased expression of the gingipain-encoding genes rgpA and kgp, suggesting that a ΔhagB/ΔhagC mutant is only viable in populations of cells that exhibit increased expression of genes involved in heme acquisition. Disruption of hagB in the fimbriated strain ATCC33277 demonstrated that HagB is also required for stable attachment of fimbriated bacteria to oral epithelial cells. Mutants of hagC were also found to form defective single and multi-species biofilms that had reduced biomass relative to biofilms formed by the wild-type strain. This study highlights the hitherto unappreciated importance of these genes in oral colonization and biofilm formation.
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Affiliation(s)
- E Connolly
- Division of Oral Biosciences, Dublin Dental University Hospital, School of Dental Science, Trinity College Dublin, University of Dublin, Dublin, Ireland
| | - E Millhouse
- Infection and Immunity Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, School of Dental Science, University of Glasgow, Glasgow, UK
| | - R Doyle
- Division of Oral Biosciences, Dublin Dental University Hospital, School of Dental Science, Trinity College Dublin, University of Dublin, Dublin, Ireland
| | - S Culshaw
- Infection and Immunity Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, School of Dental Science, University of Glasgow, Glasgow, UK
| | - G Ramage
- Infection and Immunity Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, School of Dental Science, University of Glasgow, Glasgow, UK
| | - G P Moran
- Division of Oral Biosciences, Dublin Dental University Hospital, School of Dental Science, Trinity College Dublin, University of Dublin, Dublin, Ireland
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McKenzie RME, Henry LG, Boutrin MC, Ximinies A, Fletcher HM. Role of the Porphyromonas gingivalis iron-binding protein PG1777 in oxidative stress resistance. MICROBIOLOGY-SGM 2015; 162:256-267. [PMID: 26581883 DOI: 10.1099/mic.0.000213] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Whole genome sequencing of the response of Porphyromonas gingivalis W83 to hydrogen peroxide revealed an upregulation of several uncharacterized, novel genes. Under conditions of prolonged oxidative stress in P. gingivalis, increased expression of a unique transcriptional unit carrying the grpE, dnaJ and three other hypothetical genes (PG1777, PG1778 and PG1779) was observed. The transcriptional start site of this operon appears to be located 91 bp upstream of the translational start, with a potential -10 region at -3 nt and a -35 region at -39 nt. Isogenic P. gingivalis mutants FLL273 (PG1777 : : ermF-ermAM) and FLL293 (PG1779 : : ermF-ermAM) showed increased sensitivity to and decreased survival after treatment with hydrogen peroxide. P. gingivalis FLL273 showed a fivefold increase in the formation of spontaneous mutants when compared with the parent strain after exposure to hydrogen peroxide. The recombinant PG1777 protein displayed iron-binding properties when incubated with FeSO4 and Fe(NH4)2(SO4).6H2O. The rPG1777 protein protected DNA from degradation when exposed to hydrogen peroxide in the presence of iron. Taken together, the data suggest that the grpE-dnaJ-PG1777-PG1778-PG1779 transcriptional unit may play an important role in oxidative stress resistance in P. gingivalis via its ability to protect against DNA damage.
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Affiliation(s)
- Rachelle M E McKenzie
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Leroy G Henry
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Marie-Claire Boutrin
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Alexia Ximinies
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Hansel M Fletcher
- Institute of Oral Biology, Kyung Hee University, Seoul, Republic of Korea.,Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
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Lee SW, Shet UK, Park SW, Lim HP, Yun KD, Kang SS, Kim SE. Identification of Enterococcus faecalis antigens specifically expressed in vivo. Restor Dent Endod 2015; 40:306-11. [PMID: 26587417 PMCID: PMC4650527 DOI: 10.5395/rde.2015.40.4.306] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 08/10/2015] [Indexed: 01/05/2023] Open
Abstract
Objectives Molecular mechanism of the pathogenicity of Enterococcus faecalis (E. faecalis), a suspected endodontic pathogen, has not yet been adequately elucidated due to limited information on its virulence factors. Here we report the identification of in vivo expressed antigens of E. faecalis by using a novel immunoscreening technique called change-mediated antigen technology (CMAT) and an experimental animal model of endodontic infection. Materials and Methods Among 4,500 E. coli recombinant clones screened, 19 positive clones reacted reproducibly with hyperimmune sera obtained from rabbits immunized with E. faecalis cells isolated from an experimental endodontic infection. DNA sequences from 16 of these in vivo-induced (IVI) genes were determined. Results Identified protein antigens of E. faecalis included enzymes involved in housekeeping functions, copper resistance protein, putative outer membrane proteins, and proteins of unknown function. Conclusions In vivo expressed antigens of E. faecalis could be identified by using a novel immune-screening technique CMAT and an experimental animal model of endodontic infection. Detailed analysis of these IVI genes will lead to a better understanding of the molecular mechanisms involved in the endodontic infection of E. faecalis.
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Affiliation(s)
- Seok-Woo Lee
- Department of Dental Education, Dental Science Research Institute and BK21 Project, School of Dentistry, Gwangju, Korea. ; Department of Periodontology, Dental Science Research Institute and BK21 Project, School of Dentistry, Gwangju, Korea
| | - Uttom K Shet
- Department of Maxillofacial Surgery, Dental Science Research Institute and BK21 Project, School of Dentistry, Gwangju, Korea
| | - Sang-Won Park
- Department of Prosthodontics, Dental Science Research Institute and BK21 Project, School of Dentistry, Gwangju, Korea
| | - Hyun-Pil Lim
- Department of Prosthodontics, Dental Science Research Institute and BK21 Project, School of Dentistry, Gwangju, Korea
| | - Kwi-Dug Yun
- Department of Prosthodontics, Dental Science Research Institute and BK21 Project, School of Dentistry, Gwangju, Korea
| | - Seong Soo Kang
- Department of Veterinary Medicine, Chonnam National University, Gwangju, Korea
| | - Se Eun Kim
- Department of Veterinary Medicine, Chonnam National University, Gwangju, Korea
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14
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Ye Y, Li H, Ling N, Han Y, Wu Q, Xu X, Jiao R, Gao J. Identification of potential virulence factors of Cronobacter sakazakii isolates by comparative proteomic analysis. Int J Food Microbiol 2015; 217:182-8. [PMID: 26546912 DOI: 10.1016/j.ijfoodmicro.2015.08.025] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Revised: 08/24/2015] [Accepted: 08/30/2015] [Indexed: 01/18/2023]
Abstract
Cronobacter is a group of important foodborne pathogens associated with neonatal meningitis, septicemia, and necrotizing enterocolitis. Among Cronobacter species, Cronobacter sakazakii is the most common species in terms of isolation frequency. However, the molecular basis involved in virulence differences among C. sakazakii isolates is still unknown. In this study, based on the determination of virulence differences of C. sakazakii G362 (virulent isolate) and L3101 (attenuated isolate) through intraperitoneal injection, histopathologic analysis (small intestine, kidney, and liver) further confirmed virulence differences. Thereafter, the potential virulence factors were determined using two-dimensional electrophoresis (2-DE) coupled with MALDI/TOP/TOF mass spectrometry. Among a total of 36 protein spots showing differential expression (fold change>1.2), we identified 31 different proteins, of which the expression abundance of 22 was increased in G362. These up-regulated proteins in G362 mainly contained DNA starvation/stationary phase protection protein Dps, OmpA, LuxS, ATP-dependent Clp protease ClpC, and ABC transporter substrate-binding proteins, which might be involved in virulence of C. sakazakii. This is the first report to determine the potential virulence factors of C. sakazakii isolates at the proteomic levels.
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Affiliation(s)
- Yingwang Ye
- School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei 230009, China; State Key Laboratory of Applied Microbiology, South China (the Ministry-Province Joint Development), Guangdong Provincial Key Laboratory of Microbiology Culture Collection and Application, Guangdong Institute of Microbiology, Guangzhou 510070, China
| | - Hui Li
- School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei 230009, China
| | - Na Ling
- School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei 230009, China; State Key Laboratory of Applied Microbiology, South China (the Ministry-Province Joint Development), Guangdong Provincial Key Laboratory of Microbiology Culture Collection and Application, Guangdong Institute of Microbiology, Guangzhou 510070, China
| | - Yongjia Han
- School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei 230009, China
| | - Qingping Wu
- State Key Laboratory of Applied Microbiology, South China (the Ministry-Province Joint Development), Guangdong Provincial Key Laboratory of Microbiology Culture Collection and Application, Guangdong Institute of Microbiology, Guangzhou 510070, China.
| | - Xiaoke Xu
- State Key Laboratory of Applied Microbiology, South China (the Ministry-Province Joint Development), Guangdong Provincial Key Laboratory of Microbiology Culture Collection and Application, Guangdong Institute of Microbiology, Guangzhou 510070, China
| | - Rui Jiao
- School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei 230009, China
| | - Jina Gao
- School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei 230009, China
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15
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Olsen I, Progulske-Fox A. Invasion of Porphyromonas gingivalis strains into vascular cells and tissue. J Oral Microbiol 2015; 7:28788. [PMID: 26329158 PMCID: PMC4557090 DOI: 10.3402/jom.v7.28788] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 08/06/2015] [Accepted: 08/07/2015] [Indexed: 01/06/2023] Open
Abstract
Porphyromonas gingivalis is considered a major pathogen in adult periodontitis and is also associated with multiple systemic diseases, for example, cardiovascular diseases. One of its most important virulence factors is invasion of host cells. The invasion process includes attachment, entry/internalization, trafficking, persistence, and exit. The present review discusses these processes related to P. gingivalis in cardiovascular cells and tissue. Although most P. gingivalis strains invade, the invasion capacity of strains and the mechanisms of invasion including intracellular trafficking among them differ. This is consistent with the fact that there are significant differences in the pathogenicity of P. gingivalis strains. P. gingivalis invasion mechanisms are also dependent on types of host cells. Although much is known about the invasion process of P. gingivalis, we still have little knowledge of its exit mechanisms. Nevertheless, it is intriguing that P. gingivalis can remain viable in human cardiovascular cells and atherosclerotic plaque and later exit and re-enter previously uninfected host cells.
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Affiliation(s)
- Ingar Olsen
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway;
| | - Ann Progulske-Fox
- Department of Oral Biology and Center for Molecular Microbiology, University of Florida College of Dentistry, Gainesville, FL, USA
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16
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Morgante V, Mirete S, de Figueras CG, Postigo Cacho M, González-Pastor JE. Exploring the diversity of arsenic resistance genes from acid mine drainage microorganisms. Environ Microbiol 2014; 17:1910-25. [PMID: 24801164 DOI: 10.1111/1462-2920.12505] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 04/28/2014] [Accepted: 05/01/2014] [Indexed: 11/30/2022]
Abstract
The microbial communities from the Tinto River, a natural acid mine drainage environment, were explored to search for novel genes involved in arsenic resistance using a functional metagenomic approach. Seven pentavalent arsenate resistance clones were selected and analysed to find the genes responsible for this phenotype. Insights about their possible mechanisms of resistance were obtained from sequence similarities and cellular arsenic concentration. A total of 19 individual open reading frames were analysed, and each one was individually cloned and assayed for its ability to confer arsenic resistance in Escherichia coli cells. A total of 13 functionally active genes involved in arsenic resistance were identified, and they could be classified into different global processes: transport, stress response, DNA damage repair, phospholipids biosynthesis, amino acid biosynthesis and RNA-modifying enzymes. Most genes (11) encode proteins not previously related to heavy metal resistance or hypothetical or unknown proteins. On the other hand, two genes were previously related to heavy metal resistance in microorganisms. In addition, the ClpB chaperone and the RNA-modifying enzymes retrieved in this work were shown to increase the cell survival under different stress conditions (heat shock, acid pH and UV radiation). Thus, these results reveal novel insights about unidentified mechanisms of arsenic resistance.
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Affiliation(s)
- Verónica Morgante
- Department of Molecular Evolution, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir km 4, Torrejón de Ardoz, 28850, Madrid, Spain
| | - Salvador Mirete
- Department of Molecular Evolution, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir km 4, Torrejón de Ardoz, 28850, Madrid, Spain
| | - Carolina G de Figueras
- Department of Molecular Evolution, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir km 4, Torrejón de Ardoz, 28850, Madrid, Spain
| | - Marina Postigo Cacho
- Department of Molecular Evolution, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir km 4, Torrejón de Ardoz, 28850, Madrid, Spain
| | - José E González-Pastor
- Department of Molecular Evolution, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir km 4, Torrejón de Ardoz, 28850, Madrid, Spain
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17
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Duran-Pinedo AE, Chen T, Teles R, Starr JR, Wang X, Krishnan K, Frias-Lopez J. Community-wide transcriptome of the oral microbiome in subjects with and without periodontitis. ISME JOURNAL 2014; 8:1659-72. [PMID: 24599074 DOI: 10.1038/ismej.2014.23] [Citation(s) in RCA: 217] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 01/10/2014] [Accepted: 01/20/2014] [Indexed: 01/05/2023]
Abstract
Despite increasing knowledge on phylogenetic composition of the human microbiome, our understanding of the in situ activities of the organisms in the community and their interactions with each other and with the environment remains limited. Characterizing gene expression profiles of the human microbiome is essential for linking the role of different members of the bacterial communities in health and disease. The oral microbiome is one of the most complex microbial communities in the human body and under certain circumstances, not completely understood, the healthy microbial community undergoes a transformation toward a pathogenic state that gives rise to periodontitis, a polymicrobial inflammatory disease. We report here the in situ genome-wide transcriptome of the subgingival microbiome in six periodontally healthy individuals and seven individuals with periodontitis. The overall picture of metabolic activities showed that iron acquisition, lipopolysaccharide synthesis and flagellar synthesis were major activities defining disease. Unexpectedly, the vast majority of virulence factors upregulated in subjects with periodontitis came from organisms that are not considered major periodontal pathogens. One of the organisms whose gene expression profile was characterized was the uncultured candidate division TM7, showing an upregulation of putative virulence factors in the diseased community. These data enhance understanding of the core activities that are characteristic of periodontal disease as well as the role that individual organisms in the subgingival community play in periodontitis.
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Affiliation(s)
| | - Tsute Chen
- 1] Department of Microbiology, Forsyth Institute, Cambridge, MA, USA [2] Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Harvard University, Boston, MA, USA
| | - Ricardo Teles
- 1] Department of Microbiology, Forsyth Institute, Cambridge, MA, USA [2] Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Harvard University, Boston, MA, USA
| | - Jacqueline R Starr
- 1] Department of Microbiology, Forsyth Institute, Cambridge, MA, USA [2] Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Harvard University, Boston, MA, USA
| | - Xiaoshan Wang
- 1] Department of Microbiology, Forsyth Institute, Cambridge, MA, USA [2] Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Harvard University, Boston, MA, USA
| | | | - Jorge Frias-Lopez
- 1] Department of Microbiology, Forsyth Institute, Cambridge, MA, USA [2] Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Harvard University, Boston, MA, USA
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18
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Reyes L, Eiler-McManis E, Rodrigues PH, Chadda AS, Wallet SM, Bélanger M, Barrett AG, Alvarez S, Akin D, Dunn WA, Progulske-Fox A. Deletion of lipoprotein PG0717 in Porphyromonas gingivalis W83 reduces gingipain activity and alters trafficking in and response by host cells. PLoS One 2013; 8:e74230. [PMID: 24069284 PMCID: PMC3772042 DOI: 10.1371/journal.pone.0074230] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 07/29/2013] [Indexed: 01/10/2023] Open
Abstract
P. gingivalis (Pg), a causative agent of chronic generalized periodontitis, has been implicated in promoting cardiovascular disease. Expression of lipoprotein gene PG0717 of Pg strain W83 was found to be transiently upregulated during invasion of human coronary artery endothelial cells (HCAEC), suggesting this protein may be involved in virulence. We characterized the virulence phenotype of a PG0717 deletion mutant of pg W83. There were no differences in the ability of W83Δ717 to adhere and invade HCAEC. However, the increased proportion of internalized W83 at 24 hours post-inoculation was not observed with W83∆717. Deletion of PG0717 also impaired the ability of W83 to usurp the autophagic pathway in HCAEC and to induce autophagy in Saos-2 sarcoma cells. HCAEC infected with W83Δ717 also secreted significantly greater amounts of MCP-1, IL-8, IL-6, GM-CSF, and soluble ICAM-1, VCAM-1, and E-selectin when compared to W83. Further characterization of W83Δ717 revealed that neither capsule nor lipid A structure was affected by deletion of PG0717. Interestingly, the activity of both arginine (Rgp) and lysine (Kgp) gingipains was reduced in whole-cell extracts and culture supernatant of W83Δ717. RT-PCR revealed a corresponding decrease in transcription of rgpB but not rgpA or kgp. Quantitative proteome studies of the two strains revealed that both RgpA and RgpB, along with putative virulence factors peptidylarginine deiminase and Clp protease were significantly decreased in the W83Δ717. Our results suggest that PG0717 has pleiotropic effects on W83 that affect microbial induced manipulation of host responses important for microbial clearance and infection control.
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Affiliation(s)
- Leticia Reyes
- Department of Oral Biology, College of Dentistry and Center for Molecular Microbiology, Gainesville, Florida, United States of America
| | - Eileen Eiler-McManis
- Department of Oral Biology, College of Dentistry and Center for Molecular Microbiology, Gainesville, Florida, United States of America
| | - Paulo H. Rodrigues
- Department of Oral Biology, College of Dentistry and Center for Molecular Microbiology, Gainesville, Florida, United States of America
| | - Amandeep S. Chadda
- Department of Oral Biology, College of Dentistry and Center for Molecular Microbiology, Gainesville, Florida, United States of America
| | - Shannon M. Wallet
- Department of Oral Biology, College of Dentistry and Center for Molecular Microbiology, Gainesville, Florida, United States of America
- Department of Periodontology, College of Dentistry, University of Florida, Gainesville, Florida, United States of America
| | - Myriam Bélanger
- Department of Oral Biology, College of Dentistry and Center for Molecular Microbiology, Gainesville, Florida, United States of America
| | - Amanda G. Barrett
- Department of Oral Biology, College of Dentistry and Center for Molecular Microbiology, Gainesville, Florida, United States of America
| | - Sophie Alvarez
- Donald Danforth Plant Science Center, proteomics & mass spectrometry Core, St. Louis, Missouri, United States of America
| | - Debra Akin
- Department of Anatomy and Cell Biology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - William A. Dunn
- Department of Anatomy and Cell Biology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Ann Progulske-Fox
- Department of Oral Biology, College of Dentistry and Center for Molecular Microbiology, Gainesville, Florida, United States of America
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19
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Wayakanon K, Thornhill MH, Douglas CWI, Lewis AL, Warren NJ, Pinnock A, Armes SP, Battaglia G, Murdoch C. Polymersome-mediated intracellular delivery of antibiotics to treat Porphyromonas gingivalis-infected oral epithelial cells. FASEB J 2013; 27:4455-65. [PMID: 23921377 DOI: 10.1096/fj.12-225219] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The gram-negative anaerobe Porphyromonas gingivalis colonizes the gingival crevice and is etiologically associated with periodontal disease that can lead to alveolar bone damage and resorption, promoting tooth loss. Although susceptible to antibiotics, P. gingivalis can evade antibiotic killing by residing within gingival keratinocytes. This provides a reservoir of organisms that may recolonize the gingival crevice once antibiotic therapy is complete. Polymersomes are nanosized amphiphilic block copolymer vesicles that can encapsulate drugs. Cells internalize polymersomes by endocytosis into early endosomes, where they are disassembled by the low pH, causing intracellular release of their drug load. In this study, polymersomes were used as vehicles to deliver antibiotics in an attempt to kill intracellular P. gingivalis within monolayers of keratinocytes and organotypic oral mucosal models. Polymersome-encapsulated metronidazole or doxycycline, free metronidazole, or doxycycline, or polymersomes alone as controls, were used, and the number of surviving intracellular P. gingivalis was quantified after host cell lysis. Polymersome-encapsulated metronidazole or doxycycline significantly (P<0.05) reduced the number of intracellular P. gingivalis in both monolayer and organotypic cultures compared to free antibiotic or polymersome alone controls. Polymersomes are effective delivery vehicles for antibiotics that do not normally gain entry to host cells. This approach could be used to treat recurrent periodontitis or other diseases caused by intracellular-dwelling organisms.
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Affiliation(s)
- Kornchanok Wayakanon
- 1C.M., Unit of Oral and Maxillofacial Medicine and Surgery, School of Clinical Dentistry, University of Sheffield, Claremont Crescent, Sheffield, S10 2TA, UK.
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20
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Woolard MD, Barrigan LM, Fuller JR, Buntzman AS, Bryan J, Manoil C, Kawula TH, Frelinger JA. Identification of Francisella novicida mutants that fail to induce prostaglandin E(2) synthesis by infected macrophages. Front Microbiol 2013; 4:16. [PMID: 23403609 PMCID: PMC3568750 DOI: 10.3389/fmicb.2013.00016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 01/24/2013] [Indexed: 11/13/2022] Open
Abstract
Francisella tularensis is the causative agent of tularemia. We have previously shown that infection with F. tularensis Live Vaccine Strain (LVS) induces macrophages to synthesize prostaglandin E2 (PGE2). Synthesis of PGE2 by F. tularensis infected macrophages results in decreased T cell proliferation in vitro and increased bacterial survival in vivo. Although we understand some of the biological consequences of F. tularensis induced PGE2 synthesis by macrophages, we do not understand the cellular pathways (neither host nor bacterial) that result in up-regulation of the PGE2 biosynthetic pathway in F. tularensis infected macrophages. We took a genetic approach to begin to understand the molecular mechanisms of bacterial induction of PGE2 synthesis from infected macrophages. To identify F. tularensis genes necessary for the induction of PGE2 in primary macrophages, we infected cells with individual mutants from the closely related strain F. tularensis subspecies novicida U112 (U112) two allele mutant library. Twenty genes were identified that when disrupted resulted in U112 mutant strains unable to induce the synthesis of PGE2 by infected macrophages. Fourteen of the genes identified are located within the Francisella pathogenicity island (FPI). Genes in the FPI are required for F. tularensis to escape from the phagosome and replicate in the cytosol, which might account for the failure of U112 with transposon insertions within the FPI to induce PGE2. This implies that U112 mutant strains that do not grow intracellularly would also not induce PGE2. We found that U112 clpB::Tn grows within macrophages yet fails to induce PGE2, while U112 pdpA::Tn does not grow yet does induce PGE2. We also found that U112 iglC::Tn neither grows nor induces PGE2. These findings indicate that there is dissociation between intracellular growth and the ability of F. tularensis to induce PGE2 synthesis. These mutants provide a critical entrée into the pathways used in the host for PGE2 induction.
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Affiliation(s)
- Matthew D Woolard
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center at Shreveport Shreveport, LA, USA
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21
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Pan H, Luan J, He X, Lux R, Shi W. The clpB gene is involved in the stress response of Myxococcus xanthus during vegetative growth and development. MICROBIOLOGY-SGM 2012; 158:2336-2343. [PMID: 22790397 DOI: 10.1099/mic.0.060103-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The Clp/HSP100 family of molecular chaperones is ubiquitous in both prokaryotes and eukaryotes. These proteins play important roles in refolding, disaggregating and degrading proteins damaged by stress. As a subclass of the Clp/HSP100 family, ClpB has been shown to be involved in various stress responses as well as other functions in bacteria. In the present study, we investigated the role of a predicted ClpB-encoding gene, MXAN5092, in the stress response during vegetative growth and development of Myxococcus xanthus. Transcriptional analysis confirmed induction of this clpB homologue under different stress conditions, and further phenotypic analysis revealed that an in-frame deletion mutant of MXAN5092 was more sensitive to various stress treatments than the wild-type strain during vegetative growth. Moreover, the absence of the MXAN5092 gene resulted in decreased heat tolerance of myxospores, indicating the involvement of this clpB homologue in the stress response during the development of myxospores. The M. xanthus recombinant ClpB (MXAN5092) protein also showed a general chaperone activity in vitro. Overall, our genetic and phenotypic analysis of the predicted ATP-dependent chaperone protein ClpB (MXAN5092) demonstrated that it functions as a chaperone protein and plays an important role in cellular stress tolerance during both vegetative growth and development of M. xanthus.
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Affiliation(s)
- Hongwei Pan
- School of Dentistry, University of California, Los Angeles, CA 90095, USA
| | - Jia Luan
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, CA 90095, USA
| | - Xuesong He
- School of Dentistry, University of California, Los Angeles, CA 90095, USA
| | - Renate Lux
- School of Dentistry, University of California, Los Angeles, CA 90095, USA
| | - Wenyuan Shi
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, CA 90095, USA.,School of Dentistry, University of California, Los Angeles, CA 90095, USA
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22
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McKenzie RME, Johnson NA, Aruni W, Dou Y, Masinde G, Fletcher HM. Differential response of Porphyromonas gingivalis to varying levels and duration of hydrogen peroxide-induced oxidative stress. MICROBIOLOGY-SGM 2012; 158:2465-2479. [PMID: 22745271 DOI: 10.1099/mic.0.056416-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Porphyromonas gingivalis, an anaerobic oral pathogen implicated in adult periodontitis, can exist in an environment of oxidative stress. To evaluate its adaptation to this environment, we have assessed the response of P. gingivalis W83 to varying levels and durations of hydrogen peroxide (H(2)O(2))-induced stress. When P. gingivalis was initially exposed to a subinhibitory concentration of H(2)O(2) (0.1 mM), an adaptive response to higher concentrations could be induced. Transcriptome analysis demonstrated that oxidative stress can modulate several functional classes of genes depending on the severity and duration of the exposure. A 10 min exposure to H(2)O(2) revealed increased expression of genes involved in DNA damage and repair, while after 15 min, genes involved in protein fate, protein folding and stabilization were upregulated. Approximately 9 and 2.8% of the P. gingivalis genome displayed altered expression in response to H(2)O(2) exposure at 10 and 15 min, respectively. Substantially more genes were upregulated (109 at 10 min; 47 at 15 min) than downregulated (76 at 10 min; 11 at 15 min) by twofold or higher in response to H(2)O(2) exposure. The majority of these modulated genes were hypothetical or of unknown function. One of those genes (pg1372) with DNA-binding properties that was upregulated during prolonged oxidative stress was inactivated by allelic exchange mutagenesis. The isogenic mutant P. gingivalis FLL363 (pg1372 : : ermF) showed increased sensitivity to H(2)O(2) compared with the parent strain. Collectively, our data indicate the adaptive ability of P. gingivalis to oxidative stress and further underscore the complex nature of its resistance strategy under those conditions.
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Affiliation(s)
- Rachelle M E McKenzie
- Center for Dental Research, School of Dentistry, Loma Linda University, Loma Linda, CA 92350, USA.,Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Neal A Johnson
- Department of Oral Diagnosis, Radiology, and Pathology, School of Dentistry, Loma Linda University, Loma Linda, CA 92350, USA.,Center for Dental Research, School of Dentistry, Loma Linda University, Loma Linda, CA 92350, USA
| | - Wilson Aruni
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Yuetan Dou
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Godfred Masinde
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Hansel M Fletcher
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
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Dolgilevich S, Rafferty B, Luchinskaya D, Kozarov E. Genomic comparison of invasive and rare non-invasive strains reveals Porphyromonas gingivalis genetic polymorphisms. J Oral Microbiol 2011; 3. [PMID: 21541093 PMCID: PMC3086587 DOI: 10.3402/jom.v3i0.5764] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 01/20/2011] [Accepted: 02/03/2011] [Indexed: 11/14/2022] Open
Abstract
Background Porphyromonas gingivalis strains are shown to invade human cells in vitro with different invasion efficiencies, varying by up to three orders of magnitude. Objective We tested the hypothesis that invasion-associated interstrain genomic polymorphisms are present in P. gingivalis and that putative invasion-associated genes can contribute to P. gingivalis invasion. Design Using an invasive (W83) and the only available non-invasive P. gingivalis strain (AJW4) and whole genome microarrays followed by two separate software tools, we carried out comparative genomic hybridization (CGH) analysis. Results We identified 68 annotated and 51 hypothetical open reading frames (ORFs) that are polymorphic between these strains. Among these are surface proteins, lipoproteins, capsular polysaccharide biosynthesis enzymes, regulatory and immunoreactive proteins, integrases, and transposases often with abnormal GC content and clustered on the chromosome. Amplification of selected ORFs was used to validate the approach and the selection. Eleven clinical strains were investigated for the presence of selected ORFs. The putative invasion-associated ORFs were present in 10 of the isolates. The invasion ability of three isogenic mutants, carrying deletions in PG0185, PG0186, and PG0982 was tested. The PG0185 (ragA) and PG0186 (ragB) mutants had 5.1×103-fold and 3.6×103-fold decreased in vitro invasion ability, respectively. Conclusion The annotation of divergent ORFs suggests deficiency in multiple genes as a basis for P. gingivalis non-invasive phenotype.
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Affiliation(s)
- Svetlana Dolgilevich
- Section Oral and Diagnostic Sciences, Columbia University College of Dental Medicine, New York
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de Oliveira NEM, Abranches J, Gaca AO, Laport MS, Damaso CR, Bastos MDCDF, Lemos JA, Giambiagi-deMarval M. clpB, a class III heat-shock gene regulated by CtsR, is involved in thermotolerance and virulence of Enterococcus faecalis. MICROBIOLOGY-SGM 2010; 157:656-665. [PMID: 21148206 DOI: 10.1099/mic.0.041897-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Here, we transcriptionally and phenotypically characterized the clpB gene from Enterococcus faecalis. Northern blot analysis identified a monocistronic mRNA strongly induced at 48 and 50 °C. In silico analysis identified that the clpB gene encodes a protein of 868 aa with a predicted molecular mass of approximately 98 kDa, presenting two conserved ATP-binding domains. Sequence analysis also identified a CtsR-binding box upstream of the putative -10 sequence, and inactivation of the ctsR gene resulted in an approximately 2-log increase in clpB mRNA expression, confirming ClpB as a member of the CtsR regulon. While expression of clpB was induced by heat stress, a ΔclpB strain grew relatively well under many different stressful conditions, including elevated temperatures. However, expression of ClpB appears to play a major role in induced thermotolerance and in pathogenesis, as assessed by using the Galleria mellonella virulence model.
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Affiliation(s)
- Naira Elane Moreira de Oliveira
- Center for Oral Biology, Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA
- Instituto de Microbiologia Paulo de Góes, Bloco I, Universidade Federal do Rio de Janeiro, CCS, Cidade Universitária, 21491-902, Rio de Janeiro, RJ, Brazil
| | - Jaqueline Abranches
- Center for Oral Biology, Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Anthony O Gaca
- Center for Oral Biology, Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Marinella Silva Laport
- Instituto de Microbiologia Paulo de Góes, Bloco I, Universidade Federal do Rio de Janeiro, CCS, Cidade Universitária, 21491-902, Rio de Janeiro, RJ, Brazil
| | - Clarissa R Damaso
- Instituto de Biofísica Carlos Chagas Filho, Bloco G, Universidade Federal do Rio de Janeiro, CCS, Cidade Universitária, 21491-902, Rio de Janeiro, RJ, Brazil
| | - Maria do Carmo de Freire Bastos
- Instituto de Microbiologia Paulo de Góes, Bloco I, Universidade Federal do Rio de Janeiro, CCS, Cidade Universitária, 21491-902, Rio de Janeiro, RJ, Brazil
| | - José A Lemos
- Center for Oral Biology, Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Marcia Giambiagi-deMarval
- Instituto de Microbiologia Paulo de Góes, Bloco I, Universidade Federal do Rio de Janeiro, CCS, Cidade Universitária, 21491-902, Rio de Janeiro, RJ, Brazil
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Directed screen of Francisella novicida virulence determinants using Drosophila melanogaster. Infect Immun 2010; 78:3118-28. [PMID: 20479082 DOI: 10.1128/iai.00146-10] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Francisella tularensis is a highly virulent, facultative intracellular human pathogen whose virulence mechanisms are not well understood. Occasional outbreaks of tularemia and the potential use of F. tularensis as a bioterrorist agent warrant better knowledge about the pathogenicity of this bacterium. Thus far, genome-wide in vivo screens for virulence factors have been performed in mice, all however restricted by the necessity to apply competition-based, negative-selection assays. We wanted to individually evaluate putative virulence determinants suggested by such assays and performed directed screening of 249 F. novicida transposon insertion mutants by using survival of infected fruit flies as a measure of bacterial virulence. Some 20% of the genes tested were required for normal virulence in flies; most of these had not previously been investigated in detail in vitro or in vivo. We further characterized their involvement in bacterial proliferation and pathogenicity in flies and in mouse macrophages. Hierarchical cluster analysis of mutant phenotypes indicated a functional linkage between clustered genes. One cluster grouped all but four genes of the Francisella pathogenicity island and other loci required for intracellular survival. We also identified genes involved in adaptation to oxidative stress and genes which might induce host energy wasting. Several genes related to type IV pilus formation demonstrated hypervirulent mutant phenotypes. Collectively, the data demonstrate that the bacteria in part use similar virulence mechanisms in mammals as in Drosophila melanogaster but that a considerable proportion of the virulence factors active in mammals are dispensable for pathogenicity in the insect model.
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Haslberger T, Bukau B, Mogk A. Towards a unifying mechanism for ClpB/Hsp104-mediated protein disaggregation and prion propagation. Biochem Cell Biol 2010; 88:63-75. [PMID: 20130680 DOI: 10.1139/o09-118] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The oligomeric AAA+ chaperones ClpB/Hsp104 mediate the reactivation of aggregated proteins, an activity that is crucial for the survival of cells during severe stress. Hsp104 is also essential for the propagation of yeast prions by severing prion fibres. Protein disaggregation depends on the cooperation of ClpB/Hsp104 with a cognate Hsp70 chaperone system. While Hsp70 chaperones are also involved in prion propagation, their precise role is much less well defined compared with its function in aggregate solubilization. Therefore, it remained unclear whether both ClpB/Hsp104 activities are based on common or different mechanisms. Novel data show that ClpB/Hsp104 uses a motor threading activity to remodel both protein aggregates and prion fibrils. Moreover, transfer of both types of substrates to the ClpB/Hsp104 processing pore site requires initial substrate interaction of Hsp70. Together these data emphasize the similarity of thermotolerance and prion propagation pathways and point to a shared mechanistic principle of Hsp70-ClpB/Hsp104-mediated solubilization of amorphous and ordered aggregates.
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Affiliation(s)
- Tobias Haslberger
- Zentrum für Molekulare Biologie Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Universität Heidelberg, Im Neuenheimer Feld 282, Heidelberg D-69120, Germany
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Walters S, Bélanger M, Rodrigues PH, Whitlock J, Progulske-Fox A. A member of the peptidase M48 superfamily of Porphyromonas gingivalis is associated with virulence in vitro and in vivo. J Oral Microbiol 2009; 1. [PMID: 21523206 PMCID: PMC3076999 DOI: 10.3402/jom.v1i0.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Revised: 10/15/2009] [Accepted: 10/20/2009] [Indexed: 12/03/2022] Open
Abstract
Background In vivo-induced antigen technology was previously used to identify 115 genes induced in Porphyromonas gingivalis W83 during human infection. One of these, PG2197, a conserved hypothetical protein which has homology to a Zn-dependent protease, was examined with respect to a role in disease. Design The expression of PG2197 in human periodontitis patients was investigated, but as there is increasing evidence of a direct relationship between P. gingivalis and cardiovascular disease, a mutation was constructed in this gene to also determine its role in adherence, invasion, and persistence within human coronary artery endothelial cells (HCAEC) and neutrophil killing susceptibility. Results Plaque samples from 20 periodontitis patients were analyzed by real-time PCR, revealing that PG2197 was expressed in 60.0% of diseased sites compared to 15.8% of healthy sites, even though P. gingivalis was detected in equal numbers from both sites. The expression of this gene was also found to be up-regulated in microarrays at 5 and 30 min of invasion of HCAEC. Interestingly, a PG2197 mutant displayed increased adherence, invasion, and persistence within HCAEC when compared to the wild-type strain. Conclusion This gene appears to be important for the virulence of P. gingivalis, both in vivo and in vitro.
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Affiliation(s)
- Sheila Walters
- Department of Oral Biology, Center for Molecular Microbiology, College of Dentistry, University of Florida, Gainesville, FL, USA
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Walters S, Rodrigues P, Bélanger M, Whitlock J, Progulske-Fox A. Analysis of a band 7/MEC-2 family gene of Porphyromonas gingivalis. J Dent Res 2009; 88:34-8. [PMID: 19131314 DOI: 10.1177/0022034508328381] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
In vivo-induced antigen technology has previously been used to identify 115 genes induced in Porphyromonas gingivalis W83 during human infection. The aim of this study was to determine if one of these genes, PG1334, was important for the virulence of P. gingivalis. Analysis of plaque samples from persons with periodontitis revealed that PG1334 was expressed in 88.0% of diseased sites, compared with 42.1% of healthy sites, even though P. gingivalis was detected in equal numbers from both sites. A mutant of PG1334 was found to adhere to and to invade better than the parent strain, but did not persist as well in human coronary artery endothelial cells. Additionally, the mutant did not persist as well in a mouse abscess model. This gene appears to be important for the virulence of P. gingivalis, both in vivo and in vitro.
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Affiliation(s)
- S Walters
- Department of Oral Biology, College of Dentistry and Center for Molecular Microbiology, University of Florida, Gainesville, FL 32610-0424, USA
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Jandik KA, Bélanger M, Low SL, Dorn BR, Yang MCK, Progulske-Fox A. Invasive differences among Porphyromonas gingivalis strains from healthy and diseased periodontal sites. J Periodontal Res 2008; 43:524-30. [PMID: 18544120 DOI: 10.1111/j.1600-0765.2007.01064.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND OBJECTIVE The purpose of this study was to determine any difference between Porphyromonas gingivalis isolates from periodontally healthy sites as compared to those from diseased sites with respect to the ability to invade host cells. MATERIAL AND METHODS Subgingival plaque samples were obtained from periodontally healthy and diseased sites using paper points. P. gingivalis colonies were isolated and tested, using an antibiotic protection assay, for their ability to invade KB cells. P. gingivalis 381 and Escherichia coli MC1061 were used as controls. RESULTS Mean values of 16.79 +/- 0.86 x 10(3) colony-forming units/mL and 26.14 +/- 2.11 x 10(3) colony-forming units/mL were observed in invasion assays for isolates from periodontally healthy and diseased sites, respectively. P. gingivalis present in diseased sites had significantly greater invasive abilities than strains isolated from healthy sites. No statistical difference was noted between male or female subjects concerning the degree of invasion; isolates from diseased sites from both genders had significantly greater invasion abilities than those from healthy sites. A significant correlation was found between the increased invasive capabilities of P. gingivalis isolates vs. an increased probing depth. CONCLUSION The increased invasion noted with P. gingivalis isolates from diseased sites vs. healthy sites, and the increased invasive capabilities with increasing probing depth, indicate that P. gingivalis isolates have a varying ability to invade host cells in the periodontal pocket.
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Affiliation(s)
- K A Jandik
- Department of Periodontology, College of Dentistry, University of Florida, Gainesville, FL, USA
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Yuan L, Rodrigues PH, Bélanger M, Dunn WA, Progulske-Fox A. Porphyromonas gingivalis htrA is involved in cellular invasion and in vivo survival. MICROBIOLOGY-SGM 2008; 154:1161-1169. [PMID: 18375808 DOI: 10.1099/mic.0.2007/015131-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
HtrA is a heat-stress protein that functions both as a chaperone and as a serine protease. HtrA has been shown in several organisms to be involved in responses to stressful environmental conditions and involvement of HtrA in virulence has been reported in pathogenic species. A Porphyromonas gingivalis htrA mutant demonstrated no significant difference to the W83 parent strain when subjected to high temperature and pH values from 3 to 11. However, the htrA mutant showed increased sensitivity to H(2)O(2). Cell invasion assays indicated that the total interaction (adherence) with KB cells, human coronary artery endothelial cells and gingival epithelial cells (GEC) was the same for both the wild-type and the htrA mutant. However, the htrA mutant showed increased invasion in KB cells and GEC. Microarray experiments indicated that a total of 253 genes were differentially regulated in the htrA mutant, including a group of stress-related genes, which might be responsible for the observed decreased resistance to H(2)O(2). In animal experiments, a competition assay showed that the htrA mutant did not survive as well as the wild-type. In another in vivo assay, fewer mice infected with the htrA mutant died than mice infected with W83, suggesting that the htrA gene is virulence-related. These data indicate that the htrA gene in P. gingivalis does not relate to stress conditions such as high temperature and pH, but rather to H(2)O(2) stress. The htrA gene also appears to be important for virulence and survival in in vivo animal models.
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Affiliation(s)
- Lihui Yuan
- Department of Oral Biology, College of Dentistry and Center for Molecular Microbiology, University of Florida, Gainesville, FL 32610, USA
| | - Paulo H Rodrigues
- Department of Oral Biology, College of Dentistry and Center for Molecular Microbiology, University of Florida, Gainesville, FL 32610, USA
| | - Myriam Bélanger
- Department of Oral Biology, College of Dentistry and Center for Molecular Microbiology, University of Florida, Gainesville, FL 32610, USA
| | - William A Dunn
- Department of Anatomy and Cell Biology, College of Medicine and Center for Molecular Microbiology, University of Florida, Gainesville, FL 32610, USA
| | - Ann Progulske-Fox
- Department of Oral Biology, College of Dentistry and Center for Molecular Microbiology, University of Florida, Gainesville, FL 32610, USA
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Role of the Clp system in stress tolerance, biofilm formation, and intracellular invasion in Porphyromonas gingivalis. J Bacteriol 2007; 190:1436-46. [PMID: 18065546 DOI: 10.1128/jb.01632-07] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Clp proteases and chaperones are ubiquitous among prokaryotes and eukaryotes, and in many pathogenic bacteria the Clp stress response system is also involved in regulation of virulence properties. In this study, the roles of ClpB, ClpC, and ClpXP in stress resistance, homotypic and heterotypic biofilm formation, and intracellular invasion in the oral opportunistic pathogen Porphyromonas gingivalis were investigated. Absence of ClpC and ClpXP, but not ClpB, resulted in diminished tolerance to high temperatures. Response to oxidative stress was not affected by the loss of any of the Clp proteins. The clpC and clpXP mutants demonstrated elevated monospecies biofilm formation, and the absence of ClpXP also enhanced heterotypic P. gingivalis-Streptococcus gordonii biofilm formation. All clp mutants adhered to gingival epithelial cells to the same level as the wild type; however, ClpC and ClpXP were found to be necessary for entry into host epithelial cells. ClpB did not play a role in entry but was required for intracellular replication and survival. ClpXP negatively regulated the surface exposure of the minor fimbrial (Mfa) protein subunit of P. gingivalis, which stimulates biofilm formation but interferes with epithelial cell entry. Collectively, these results show that the Clp protease complex and chaperones control several processes that are important for the colonization and survival of P. gingivalis in the oral cavity.
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