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Stojkova P, Spidlova P. Bacterial nucleoid-associated protein HU as an extracellular player in host-pathogen interaction. Front Cell Infect Microbiol 2022; 12:999737. [PMID: 36081771 PMCID: PMC9445418 DOI: 10.3389/fcimb.2022.999737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 08/01/2022] [Indexed: 11/17/2022] Open
Abstract
HU protein is a member of nucleoid-associated proteins (NAPs) and is an important regulator of bacterial virulence, pathogenesis and survival. NAPs are mainly DNA structuring proteins that influence several molecular processes by binding the DNA. HU´s indispensable role in DNA-related processes in bacteria was described. HU protein is a necessary bacterial transcription factor and is considered to be a virulence determinant as well. Less is known about its direct role in host-pathogen interactions. The latest studies suggest that HU protein may be secreted outside bacteria and be a part of the extracellular matrix. Moreover, HU protein can be internalized in a host cell after bacterial infection. Its role in the host cell is not well described and further studies are extremely needed. Existing results suggest the involvement of HU protein in host cell immune response modulation in bacterial favor, which can help pathogens resist host defense mechanisms. A better understanding of the HU protein’s role in the host cell will help to effective treatment development.
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Center SA, Randolph JF, Warner KL, McDonough SP, Lucy JM, Sapa KC. Bacterial culture and immunohistochemical detection of bacteria and endotoxin in cats with suppurative cholangitis-cholangiohepatitis syndrome. J Am Vet Med Assoc 2021; 260:194-211. [PMID: 34936576 DOI: 10.2460/javma.20.10.0552] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE To characterize the frequency and type of bacterial infection by culture- and immunohistochemical (IHC)-based methods and determine the impact of infection on clinical features and survival time in cats with suppurative cholangitis-cholangiohepatitis syndrome (S-CCHS). ANIMALS 168 client-owned cats with S-CCHS (cases). PROCEDURES Clinical features, bacterial culture results, culture-inoculate sources, and survival details were recorded. Cases were subcategorized by comorbidity (extrahepatic bile duct obstruction, cholelithiasis, cholecystitis, ductal plate malformation, biopsy-confirmed inflammatory bowel disease, and biopsy-confirmed pancreatitis) or treatment by cholecystectomy or cholecystoenterostomy. Culture results, bacterial isolates, Gram-stain characteristics, and IHC staining were compared among comorbidities. Lipoteichoic acid IHC staining detected gram-positive bacterial cell wall components, and toll-like receptor expression IHC reflected pathologic endotoxin (gram-negative bacteria) exposure. RESULTS Clinical features were similar among cases except for more frequent abdominal pain and lethargy in cats with positive culture results and pyrexia, abdominal pain, and hepatomegaly for cats with polymicrobial infections. Bacteria were cultured in 93 of 135 (69%) cats, with common isolates including Enterococcus spp and Escherichia coli. IHC staining was positive in 142 of 151 (94%) cats (lipoteichoic acid, 107/142 [75%]; toll-like receptor 4, 99/142 [70%]). With in-parallel interpretation of culture and IHC-based bacterial detection, 154 of 166 (93%) cats had bacterial infections (gram-positive, 118/154 [77%]; gram-negative, 111/154 [72%]; polymicrobial, 79/154 [51%]). Greater frequency of bacterial isolation occurred with combined tissue, bile, and crushed cholelith inoculates. Infection and gram-positive bacterial isolates were associated with significantly shorter long-term survival times. CLINICAL RELEVANCE S-CCHS was associated with bacterial infection, pathologic endotoxin exposure, and frequent polymicrobial infection in cats. Combined tissue inoculates improved culture detection of associated bacteria.
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Affiliation(s)
- Sharon A Center
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY
| | - John F Randolph
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY
| | - Karen L Warner
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY
| | - Sean P McDonough
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY
| | | | - Kirk C Sapa
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY
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3
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Nesbitt H, Burke C, Haghi M. Manipulation of the Upper Respiratory Microbiota to Reduce Incidence and Severity of Upper Respiratory Viral Infections: A Literature Review. Front Microbiol 2021; 12:713703. [PMID: 34512591 PMCID: PMC8432964 DOI: 10.3389/fmicb.2021.713703] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 08/06/2021] [Indexed: 12/12/2022] Open
Abstract
There is a high incidence of upper respiratory viral infections in the human population, with infection severity being unique to each individual. Upper respiratory viruses have been associated previously with secondary bacterial infection, however, several cross-sectional studies analyzed in the literature indicate that an inverse relationship can also occur. Pathobiont abundance and/or bacterial dysbiosis can impair epithelial integrity and predispose an individual to viral infection. In this review we describe common commensal microorganisms that have the capacity to reduce the abundance of pathobionts and maintain bacterial symbiosis in the upper respiratory tract and discuss the potential and limitations of localized probiotic formulations of commensal bacteria to reduce the incidence and severity of viral infections.
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Affiliation(s)
- Henry Nesbitt
- Discipline of Pharmacy, Graduate School Health, University of Technology Sydney, Sydney, NSW, Australia
| | - Catherine Burke
- School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia
| | - Mehra Haghi
- Discipline of Pharmacy, Graduate School Health, University of Technology Sydney, Sydney, NSW, Australia
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4
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Vezina B, Al-Harbi H, Ramay HR, Soust M, Moore RJ, Olchowy TWJ, Alawneh JI. Sequence characterisation and novel insights into bovine mastitis-associated Streptococcus uberis in dairy herds. Sci Rep 2021; 11:3046. [PMID: 33542314 PMCID: PMC7862697 DOI: 10.1038/s41598-021-82357-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 01/20/2021] [Indexed: 12/16/2022] Open
Abstract
Streptococcus uberis is one of the most frequent mastitis-causing pathogens isolated from dairy cows. Further understanding of S. uberis genetics may help elucidate the disease pathogenesis. We compared the genomes of S. uberis isolates cultured from dairy cows located in distinctly different geographic regions of Australia. All isolates had novel multi locus sequence types (MLST) indicating a highly diverse population of S. uberis. Global clonal complexes (GCC) were more conserved. GCC ST86 and GCC ST143 represented 30% of the total isolates (n = 27) and were clustered within different geographic regions. Core genome phylogeny revealed low phylogenetic clustering by region, isolation source, and MLST. Identification of putative sortase (srtA) substrates and generation of a custom putative virulence factor database revealed genes which may explain the affinity of S. uberis for mammary tissue, evasion of antimicrobial efforts and disease pathogenesis. Of 27 isolates, four contained antibiotic resistance genes including an antimicrobial resistance cluster containing mel/mef(A), mrsE, vatD, lnuD, and transposon-mediated lnuC was also identified. These are novel genes for S. uberis, which suggests interspecies lateral gene transfer. The presence of resistance genes across the two geographic regions tested within one country supports the need for a careful, tailored, implementation and monitoring of antimicrobial stewardship.
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Affiliation(s)
- Ben Vezina
- Good Clinical Practice Research Group (GCPRG), The University of Queensland, School of Veterinary Science, Gatton, QLD, 4343, Australia.,Centre for Cell Factories and Biopolymers, Griffith Institute for Drug Discovery, Griffith University, Nathan, Australia
| | - Hulayyil Al-Harbi
- The University of Queensland, School of Veterinary Science, Gatton, QLD, 4343, Australia
| | - Hena R Ramay
- International Microbiome Centre, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Martin Soust
- Terragen Biotech Pty Ltd., Coolum Beach, QLD, 4573, Australia
| | - Robert J Moore
- School of Science, RMIT University, Bundoora, Melbourne, 3083, Australia
| | - Timothy W J Olchowy
- Good Clinical Practice Research Group (GCPRG), The University of Queensland, School of Veterinary Science, Gatton, QLD, 4343, Australia.,Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, T3R 1J3, Canada
| | - John I Alawneh
- Good Clinical Practice Research Group (GCPRG), The University of Queensland, School of Veterinary Science, Gatton, QLD, 4343, Australia. .,The University of Queensland, School of Veterinary Science, Gatton, QLD, 4343, Australia.
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5
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Expression of an Extracellular Protein (SMU.63) Is Regulated by SprV in Streptococcus mutans. Appl Environ Microbiol 2020; 86:AEM.01647-20. [PMID: 32978138 DOI: 10.1128/aem.01647-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 09/20/2020] [Indexed: 12/19/2022] Open
Abstract
In Streptococcus mutans, SprV (SMU.2137) is a pleiotropic regulator that differentially regulates genes related to competence, mutacin production, biofilm formation, and the stress tolerance response, along with some other pathways. In this study, we established a link between SprV and an ∼67-kDa protein in the culture supernatant of strain UA159 that was later confirmed as SMU.63 by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis. We discovered that SprV downregulates the transcription and translation of SMU.63. We found that the seven amino acids from the C-terminal region of SprV were also crucial for the expression of SMU.63. Deletion of smu.63 led to increased sucrose-independent biofilm formation and competence. The sprV deletion also increased biofilm formation although this could be partially attributed to the downregulation of smu.63 In an smu.63 sprV double mutant, a synergistic effect was observed in biofilm formation in contrast to effects on competence development. We found that low or excess magnesium ion repressed sprV transcription that, in turn, affected the expression of smu.63 As expected, a magnesium ion-dependent effect of competence and biofilm formation was observed in the UA159 strain. We also replicated the results of SMU.63 expression and competence in S. mutans GS5 that encodes both SprV and SMU.63 homologs and found that the GS5 strain behaves similarly to the UA159 strain, indicating that SprV's effect is strain independent.IMPORTANCE We previously identified a pleiotropic regulator, SprV, in Streptococcus mutans This regulator appears to be highly conserved among streptococci. Here, we showed that SprV regulates the expression of a secreted protein encoded by SMU.63 in S. mutans SMU.63 has been known to impact biofilm formation and genetic competence, two important characteristics that help in colonization of the organism. SMU.63 is also unique since it is known to form amyloid fiber. We found that SprV regulates the expression of SMU.63 at both the transcriptional and translational levels. We also found that the expression of SprV is regulated by magnesium ion concentration. Interestingly, both low and high magnesium ion concentrations affected biofilm formation and genetic competence. Since SMU.63 is also highly conserved among streptococci, we hypothesized that SprV will have a similar effect on its expression.
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Mosquera J, Pedreañez A. Acute post-streptococcal glomerulonephritis: analysis of the pathogenesis. Int Rev Immunol 2020; 40:381-400. [PMID: 33030969 DOI: 10.1080/08830185.2020.1830083] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Increasing evidence supports a central role of the immune system in acute post streptococcal glomerulonephritis (APSGN), but the current view of how streptococcal biology affects immunity, and vice versa, remains to be clarified. Renal glomerular immune complex deposition is critical in the initiation of APSGN; however, mechanisms previous to immune complex formation could modulate the initiation and the progression of the disease. Initial and late renal events involved in the nephritis can also be related to host factors and streptococcal factors. In this review we describe the mechanisms reported for the APSGN pathogenesis, the interactions of streptococcal products with renal cells and leukocytes, the possible effects of different nephritogenic antigens in the renal environment and the possibility that APSGN is not just due to a single streptococcal antigen and its antibody; instead, kidney damage may be the result of different factors acting at the same time related to both streptococcus and host factors. Addressing these points should help us to better understand APSGN physiopathology.
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Affiliation(s)
- Jesús Mosquera
- Facultad de Medicina, Instituto de Investigaciones Clínicas "Dr. Américo Negrette", Universidad del Zulia, Maracaibo, Venezuela
| | - Adriana Pedreañez
- Facultad de Medicina, Cátedra de Inmunología, Escuela de Bioanálisis, Universidad del Zulia, Maracaibo, Venezuela
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Ogawa D, Suzuki M, Inamura Y, Saito K, Hasunuma I, Kobayashi T, Kikuyama S, Iwamuro S. Antimicrobial Property and Mode of Action of the Skin Peptides of the Sado Wrinkled Frog, Glandirana susurra, against Animal and Plant Pathogens. Antibiotics (Basel) 2020; 9:antibiotics9080457. [PMID: 32751229 PMCID: PMC7460468 DOI: 10.3390/antibiotics9080457] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 07/24/2020] [Accepted: 07/27/2020] [Indexed: 11/16/2022] Open
Abstract
The Sado wrinkled frog Glandirana susurra has recently been classified as a new frog species endemic to Sado Island, Japan. In this study, we cloned 12 cDNAs encoding the biosynthetic precursors for brevinin-2SSa–2SSd, esculentin-2SSa, ranatuerin-2SSa, brevinin-1SSa–1SSd, granuliberin-SSa, and bradykinin-SSa from the skin of G. susurra. Among these antimicrobial peptides, we focused on brevinin-2SSb, ranatuerin-2SSa, and granuliberin-SSa, using their synthetic replicates to examine their activities against different reference strains of pathogenic microorganisms that infect animals and plants. In broth microdilution assays, brevinin-2SSb displayed antimicrobial activities against animal pathogens Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa, and Candida albicans and plant pathogens Xanthomonas oryzae pv. oryzae, Clavibacter michiganensis subsp. michiganensis, and Pyricularia oryzae. Ranatuerin-2SSa and granuliberin-SSa were active against C. albicans and C. michiganensis subsp. michiganensis, and granuliberin-SSa also was active against the other plant pathogenic microbes. Scanning electron microscopic observations demonstrated that brevinin-2SSb, ranatuerin-2SSa, and granuliberin-SSa induced morphological abnormalities on the cell surface in a wide range of the reference pathogens. To assess the bacterial-endotoxin-binding ability of the peptides, we developed an enzyme-linked endotoxin-binding assay system and demonstrated that brevinin-2SSb and ranatuerin-2SSa both exhibited high affinity to lipopolysaccharide and moderate affinity to lipoteichoic acid.
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Affiliation(s)
- Daisuke Ogawa
- Department of Biology, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan; (D.O.); (M.S.); (Y.I.); (K.S.); (I.H.)
| | - Manami Suzuki
- Department of Biology, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan; (D.O.); (M.S.); (Y.I.); (K.S.); (I.H.)
| | - Yuriko Inamura
- Department of Biology, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan; (D.O.); (M.S.); (Y.I.); (K.S.); (I.H.)
| | - Kaito Saito
- Department of Biology, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan; (D.O.); (M.S.); (Y.I.); (K.S.); (I.H.)
| | - Itaru Hasunuma
- Department of Biology, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan; (D.O.); (M.S.); (Y.I.); (K.S.); (I.H.)
| | - Tetsuya Kobayashi
- Department of Regulatory Biology, Faculty of Sciences, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan;
| | - Sakae Kikuyama
- Department of Biology, Faculty of Education and Integrated Arts and Sciences, Center for Advanced Biomedical Sciences, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan;
| | - Shawichi Iwamuro
- Department of Biology, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan; (D.O.); (M.S.); (Y.I.); (K.S.); (I.H.)
- Correspondence: ; Tel.: +81-47-472-5206
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8
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Novotny LA, Goodman SD, Bakaletz LO. Redirecting the immune response towards immunoprotective domains of a DNABII protein resolves experimental otitis media. NPJ Vaccines 2019; 4:43. [PMID: 31632744 PMCID: PMC6791836 DOI: 10.1038/s41541-019-0137-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 09/13/2019] [Indexed: 12/18/2022] Open
Abstract
The chronicity and recurrence of many bacterial diseases is largely attributable to the presence of a biofilm, and eradication of these structures is confounded by an extracellular DNA-rich matrix. DNABII proteins, including integration host factor (IHF), are critical components of the matrix formed by all human pathogens tested to date. Whereas the natural adaptive immune response to IHF is against non-protective epitopes within the carboxyl-terminal region, antibodies against the DNA-binding “tips” induce biofilm collapse. We designed a “tip-chimer” immunogen to mimic the DNA-binding regions within the α-subunit and β-subunit of IHF from nontypeable Haemophilus influenzae (IHFNTHi). Re-direction of the natural adaptive immune response toward immunoprotective domains disrupted NTHi biofilms in vitro and in an experimental model of otitis media. Our data support the rational design of a powerful therapeutic approach, and also that of a DNABII-directed vaccine antigen that would avoid augmentation of any pre-existing natural, but nonprotective, immune response. Bacterial biofilms are characterized by the presence of a protective extracellular polymeric substance (EPS) that incorporates both eDNA and members of the DNABII family of bacterial DNA-binding proteins. Antibodies against the “tips” of these DNA binding-domains can cause biofilm collapse, but these epitopes are masked from the host adaptive immune system when bound to eDNA, making biofilm eradication difficult. Here, the team led by Lauren Bakaletz used a chimeric peptide to generate tip-specific antibodies against nontypeable Haemophilus influenzae to treat biofilms in vitro and in vivo. The “tip-chimer” contained the immunoprotective domains from the DNA-binding tips of a DNABII protein, integration host factor (IHF), expressed by nontypeable Haemophilus influenzae. The consequent antibodies disrupted H. influenzae biofilms in vitro and were used to treat a chinchilla model of experimental otitis media when inoculated directly into the middle ear, resulting in reduced bacterial load and clearance of already established mucosal biofilms. These findings suggest that redirecting the host adaptive immune response towards the immunoprotective tips of DNABII proteins could provide a strategy to eradicate biofilms caused by various pathogens that produce these proteins.
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Affiliation(s)
- L A Novotny
- 1Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH 43205 USA
| | - S D Goodman
- 1Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH 43205 USA.,2The Ohio State University College of Medicine, Columbus, OH 43210 USA
| | - L O Bakaletz
- 1Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH 43205 USA.,2The Ohio State University College of Medicine, Columbus, OH 43210 USA
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Wang W, Chen J, Liao B, Xia L, Hou S, Wang Z, Lu Y. Identification and functional characterization of Histone-like DNA-binding protein in Nocardia seriolae (NsHLP) involved in cell apoptosis. JOURNAL OF FISH DISEASES 2019; 42:657-666. [PMID: 30854666 DOI: 10.1111/jfd.12962] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 12/29/2018] [Accepted: 12/31/2018] [Indexed: 06/09/2023]
Abstract
Nocardia seriolae, a facultative intracellular bacterium, is the main pathogen of fish nocardiosis. Bioinformatic analysis showed that the histone-like DNA-binding protein (HLP) gene of N. seriolae (nshlp) encoded a secreted protein and might target the mitochondria in the host cell. To further study the preliminary function of HLP in N. seriolae (NsHLP), the gene cloning, extracellular products identification, subcellular localization, overexpression and apoptosis detection assay were carried out in this study. Mass spectrometry analysis of the extracellular products from N. seriolae showed that NsHLP was a secreted protein. Subcellular localization of HLP-GFP fusion proteins mainly assembled in the nucleus, which indicated that the NsHLP was co-located with the nucleus rather than mitochondria in fathead minnow (FHM) cells. Notably, the expression of NsHLP had changed the distribution of mitochondria into lumps in the FHM cell. In addition, apoptotic features were found in the transfected FHM cells by overexpression of NsHLP. Quantitative assays of mitochondrial membrane potential value, caspase-3 activity and pro-apoptotic genes mRNA (Bad, Bid and Bax) expression level demonstrated that the cell apoptosis was induced in the transfected FHM cells. All the results presented in this study provided insight on the function of NsHLP, which suggested that it may participate in the cell apoptosis regulation and play an important role in the pathogenesis of N. seriolae.
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Affiliation(s)
- Wenji Wang
- Shenzhen Research Institute of Guangdong Ocean University, Shenzhen, China
- Fisheries College of Guangdong Ocean University, Zhanjiang, China
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Zhanjiang, China
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen, China
| | - Jianlin Chen
- Shenzhen Research Institute of Guangdong Ocean University, Shenzhen, China
- Fisheries College of Guangdong Ocean University, Zhanjiang, China
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Zhanjiang, China
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen, China
| | - Baoshan Liao
- Fisheries College of Guangdong Ocean University, Zhanjiang, China
| | - Liqun Xia
- Shenzhen Research Institute of Guangdong Ocean University, Shenzhen, China
- Fisheries College of Guangdong Ocean University, Zhanjiang, China
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen, China
| | - Suying Hou
- Shenzhen Research Institute of Guangdong Ocean University, Shenzhen, China
- Fisheries College of Guangdong Ocean University, Zhanjiang, China
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Zhanjiang, China
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen, China
| | - Zhiwen Wang
- Shenzhen Research Institute of Guangdong Ocean University, Shenzhen, China
- Fisheries College of Guangdong Ocean University, Zhanjiang, China
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Zhanjiang, China
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen, China
| | - Yishan Lu
- Shenzhen Research Institute of Guangdong Ocean University, Shenzhen, China
- Fisheries College of Guangdong Ocean University, Zhanjiang, China
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Zhanjiang, China
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen, China
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10
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Ferrándiz MJ, Carreño D, Ayora S, de la Campa AG. HU of Streptococcus pneumoniae Is Essential for the Preservation of DNA Supercoiling. Front Microbiol 2018; 9:493. [PMID: 29662473 PMCID: PMC5890176 DOI: 10.3389/fmicb.2018.00493] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 03/02/2018] [Indexed: 01/11/2023] Open
Abstract
The histone-like protein HU is a conserved nucleoid-associated protein that is involved in the maintenance of the bacterial chromosome architecture. It is the only known nucleoid-associated protein in Streptococcus pneumoniae, but it has not been studied. The pneumococcal gene encoding this protein, hlp, is shown herein to be essential for cell viability. Its disruption was only possible either when it was duplicated in the chromosome and its expression induced from the P Zn promoter, or when hlp was cloned into a plasmid under the control of the inducible P mal promoter. In vitro assays indicated that pneumococcal HU shows a preference for binding to supercoiled DNA rather than to linear or nicked DNA. In vivo experiments in which the amount of HU was manipulated showed a relationship between the amount of HU and the level of DNA supercoiling. A twofold reduction in the amount of HU triggered a 21% increase in DNA relaxation in untreated cells. However, in cells treated with novobiocin, a drug that relaxes DNA by inhibiting DNA gyrase, a 35% increase in DNA relaxation was observed, instead of the expected 20% in cells with a constitutive HU amount. Conversely, a fourfold HU increase caused only 14% of DNA relaxation in the presence of novobiocin. Taken together, these results support an essential role for HU in the maintenance of DNA supercoiling in S. pneumoniae.
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Affiliation(s)
- María-José Ferrándiz
- Unidad de Genética Bacteriana, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
| | - David Carreño
- Unidad de Genética Bacteriana, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
| | - Silvia Ayora
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Adela G de la Campa
- Unidad de Genética Bacteriana, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain.,Presidencia, Consejo Superior de Investigaciones Científicas, Madrid, Spain
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11
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Le Rhun A, Beer YY, Reimegård J, Chylinski K, Charpentier E. RNA sequencing uncovers antisense RNAs and novel small RNAs in Streptococcus pyogenes. RNA Biol 2016; 13:177-95. [PMID: 26580233 PMCID: PMC4829319 DOI: 10.1080/15476286.2015.1110674] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Streptococcus pyogenes is a human pathogen responsible for a wide spectrum of diseases ranging from mild to life-threatening infections. During the infectious process, the temporal and spatial expression of pathogenicity factors is tightly controlled by a complex network of protein and RNA regulators acting in response to various environmental signals. Here, we focus on the class of small RNA regulators (sRNAs) and present the first complete analysis of sRNA sequencing data in S. pyogenes. In the SF370 clinical isolate (M1 serotype), we identified 197 and 428 putative regulatory RNAs by visual inspection and bioinformatics screening of the sequencing data, respectively. Only 35 from the 197 candidates identified by visual screening were assigned a predicted function (T-boxes, ribosomal protein leaders, characterized riboswitches or sRNAs), indicating how little is known about sRNA regulation in S. pyogenes. By comparing our list of predicted sRNAs with previous S. pyogenes sRNA screens using bioinformatics or microarrays, 92 novel sRNAs were revealed, including antisense RNAs that are for the first time shown to be expressed in this pathogen. We experimentally validated the expression of 30 novel sRNAs and antisense RNAs. We show that the expression profile of 9 sRNAs including 2 predicted regulatory elements is affected by the endoribonucleases RNase III and/or RNase Y, highlighting the critical role of these enzymes in sRNA regulation.
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Affiliation(s)
- Anaïs Le Rhun
- a The Laboratory for Molecular Infection Sweden (MIMS), Umeå Center for Microbial Research (UCMR), Department of Molecular Biology; Umeå University, S-90187 , Umeå , Sweden.,b Helmholtz Centre for Infection Research (HZI), Department of Regulation in Infection Biology, D-38124 , Braunschweig , Germany
| | - Yan Yan Beer
- b Helmholtz Centre for Infection Research (HZI), Department of Regulation in Infection Biology, D-38124 , Braunschweig , Germany
| | - Johan Reimegård
- c Science for Life Laboratory , Department of Cell and Molecular Biology, Uppsala University, S-75003 , Uppsala , Sweden
| | - Krzysztof Chylinski
- a The Laboratory for Molecular Infection Sweden (MIMS), Umeå Center for Microbial Research (UCMR), Department of Molecular Biology; Umeå University, S-90187 , Umeå , Sweden.,d Max F. Perutz Laboratories (MFPL), University of Vienna, A-1030 , Vienna , Austria
| | - Emmanuelle Charpentier
- a The Laboratory for Molecular Infection Sweden (MIMS), Umeå Center for Microbial Research (UCMR), Department of Molecular Biology; Umeå University, S-90187 , Umeå , Sweden.,b Helmholtz Centre for Infection Research (HZI), Department of Regulation in Infection Biology, D-38124 , Braunschweig , Germany.,e Hannover Medical School (MHH), D-30625 , Hannover , Germany.,f Max Planck Institute for Infection Biology , Department of Regulation in Infection Biology, D-10117 , Berlin , Germany
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Novotny LA, Jurcisek JA, Goodman SD, Bakaletz LO. Monoclonal antibodies against DNA-binding tips of DNABII proteins disrupt biofilms in vitro and induce bacterial clearance in vivo. EBioMedicine 2016; 10:33-44. [PMID: 27342872 PMCID: PMC5006588 DOI: 10.1016/j.ebiom.2016.06.022] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 06/13/2016] [Accepted: 06/15/2016] [Indexed: 12/23/2022] Open
Abstract
The vast majority of chronic and recurrent bacterial diseases are attributed to the presence of a recalcitrant biofilm that contributes significantly to pathogenesis. As such, these diseases will require an innovative therapeutic approach. We targeted DNABII proteins, an integral component of extracellular DNA (eDNA) which is universally found as part of the pathogenic biofilm matrix to develop a biofilm disrupting therapeutic. We show that a cocktail of monoclonal antibodies directed against specific epitopes of a DNABII protein is highly effective to disrupt diverse biofilms in vitro as well as resolve experimental infection in vivo, in both a chinchilla and murine model. Combining this monoclonal antibody cocktail with a traditional antibiotic to kill bacteria newly released from the biofilm due to the action of the antibody cocktail was highly effective. Our results strongly support these monoclonal antibodies as attractive candidates for lead optimization as a therapeutic for resolution of bacterial biofilm diseases. Monoclonal antibodies (MAbs) against protective epitopes of a DNABII protein disrupted diverse bacterial biofilms in vitro. Delivery of these MAbs also provided therapeutic efficacy in two animal models of biofilm infection. Bacteria newly released from the biofilm by the action of the MAbs were susceptible to host-mediated clearance and tobramycin.
Research In Context The bacteria which cause the vast majority of chronic and recurrent diseases characteristically form ‘biofilms’. Biofilms are communities of bacteria with many unique properties, including being highly resistant to antibiotics and the body's immune response. To develop an effective therapeutic for biofilm infections, we targeted the DNABII proteins, a universal biofilm component that provides structural integrity. Monoclonal antibodies against domains of the DNABII proteins induced complete collapse of diverse biofilms with release of resident bacteria that were highly susceptible to killing by host immune effectors and traditional antibiotics. This therapeutic also mediated resolution of infection in two experimental animal models.
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Affiliation(s)
- Laura A Novotny
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205, USA; The Ohio State University College of Medicine, Department of Pediatrics, 700 Children's Drive, Columbus, OH, 43205, USA.
| | - Joseph A Jurcisek
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205, USA; The Ohio State University College of Medicine, Department of Pediatrics, 700 Children's Drive, Columbus, OH, 43205, USA.
| | - Steven D Goodman
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205, USA; The Ohio State University College of Medicine, Department of Pediatrics, 700 Children's Drive, Columbus, OH, 43205, USA.
| | - Lauren O Bakaletz
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205, USA; The Ohio State University College of Medicine, Department of Pediatrics, 700 Children's Drive, Columbus, OH, 43205, USA.
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Arntzen MØ, Karlskås IL, Skaugen M, Eijsink VGH, Mathiesen G. Proteomic Investigation of the Response of Enterococcus faecalis V583 when Cultivated in Urine. PLoS One 2015; 10:e0126694. [PMID: 25915650 PMCID: PMC4411035 DOI: 10.1371/journal.pone.0126694] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 04/07/2015] [Indexed: 11/19/2022] Open
Abstract
Enterococcus faecalis is a robust bacterium, which is able to survive in and adapt to hostile environments such as the urinary tract and bladder. In this label-free quantitative proteomic study based on MaxQuant LFQ algorithms, we identified 127 proteins present in the secretome of the clinical vancomycin-resistant isolate E. faecalis V583 and we compared proteins secreted in the initial phase of cultivation in urine with the secretome during cultivation in standard laboratory medium, 2xYT. Of the 54 identified proteins predicted to be secreted, six were exclusively found after cultivation in urine including the virulence factor EfaA ("endocarditis specific antigen") and its homologue EF0577 ("adhesion lipoprotein"). These two proteins are both involved in manganese transport, known to be an important determinant of colonization and infection, and may additionally function as adhesins. Other detected urine-specific proteins are involved in peptide transport (EF0063 and EF3106) and protease inhibition (EF3054). In addition, we found an uncharacterized protein (EF0764), which had not previously been linked to the adaptation of V583 to a urine environment, and which is unique to E. faecalis. Proteins found in both environments included a histone-like protein, EF1550, that was up-regulated during cultivation in urine and that has a homologue in streptococci (HlpA) known to be involved in bacterial adhesion to host cells. Up-regulated secreted proteins included autolysins. These results from secretome analyses are largely compatible with previously published data from transcriptomics studies. All in all, the present data indicate that transport, in particular metal transport, adhesion, cell wall remodelling and the unknown function carried out by the unique EF0764 are important for enterococcal adaptation to the urine environment. These results provide a basis for a more targeted exploration of novel proteins involved in the adaptability and pathogenicity of E. faecalis.
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Affiliation(s)
- Magnus Øverlie Arntzen
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
- * E-mail:
| | - Ingrid Lea Karlskås
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
| | - Morten Skaugen
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
| | - Vincent G. H. Eijsink
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
| | - Geir Mathiesen
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
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Ceccarelli D, Hasan NA, Huq A, Colwell RR. Distribution and dynamics of epidemic and pandemic Vibrio parahaemolyticus virulence factors. Front Cell Infect Microbiol 2013; 3:97. [PMID: 24377090 PMCID: PMC3858888 DOI: 10.3389/fcimb.2013.00097] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 11/23/2013] [Indexed: 12/18/2022] Open
Abstract
Vibrio parahaemolyticus, autochthonous to estuarine, marine, and coastal environments throughout the world, is the causative agent of food-borne gastroenteritis. More than 80 serotypes have been described worldwide, based on antigenic properties of the somatic (O) and capsular (K) antigens. Serovar O3:K6 emerged in India in 1996 and subsequently was isolated worldwide, leading to the conclusion that the first V. parahaemolyticus pandemic had taken place. Most strains of V. parahaemolyticus isolated from the environment or seafood, in contrast to clinical strains, do not produce a thermostable direct hemolysin (TDH) and/or a TDH-related hemolysin (TRH). Type 3 secretion systems (T3SSs), needle-like apparatuses able to deliver bacterial effectors into host cytoplasm, were identified as triggering cytotoxicity and enterotoxicity. Type 6 secretion systems (T6SS) predicted to be involved in intracellular trafficking and vesicular transport appear to play a role in V. parahaemolyticus virulence. Recent advances in V. parahaemolyticus genomics identified several pathogenicity islands (VpaIs) located on either chromosome in both epidemic and pandemic strains and comprising additional colonization factors, such as restriction-modification complexes, chemotaxis proteins, classical bacterial surface virulence factors, and putative colicins. Furthermore, studies indicate strains lacking toxins and genomic regions associated with pathogenicity may also be pathogenic, suggesting other important virulence factors remain to be identified. The unique repertoire of virulence factors identified to date, their occurrence and distribution in both epidemic and pandemic strains worldwide are described, with the aim of highlighting the complexity of V. parahaemolyticus pathogenicity as well as its dynamic genome.
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Affiliation(s)
- Daniela Ceccarelli
- Maryland Pathogen Research Institute, University of Maryland College Park, MD, USA
| | - Nur A Hasan
- Maryland Pathogen Research Institute, University of Maryland College Park, MD, USA ; CosmosID Inc. College Park, MD, USA
| | - Anwar Huq
- Maryland Pathogen Research Institute, University of Maryland College Park, MD, USA ; Maryland Institute of Applied Environmental Health, University of Maryland College Park, MD, USA
| | - Rita R Colwell
- Maryland Pathogen Research Institute, University of Maryland College Park, MD, USA ; CosmosID Inc. College Park, MD, USA ; Maryland Institute of Applied Environmental Health, University of Maryland College Park, MD, USA ; Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University Baltimore, MD, USA
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Morita S, Tagai C, Shiraishi T, Miyaji K, Iwamuro S. Differential mode of antimicrobial actions of arginine-rich and lysine-rich histones against Gram-positive Staphylococcus aureus. Peptides 2013; 48:75-82. [PMID: 23932939 DOI: 10.1016/j.peptides.2013.07.025] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 07/30/2013] [Accepted: 07/30/2013] [Indexed: 11/28/2022]
Abstract
We previously reported the activities and modes of action of arginine (Arg)-rich histones H3 and H4 against Gram-negative bacteria. In the present study, we investigated the properties of the Arg-rich histones against Gram-positive bacteria in comparison with those of lysine (Lys)-rich histone H2B. In a standard microdilution assay, calf thymus histones H2B, H3, and H4 showed growth inhibitory activity against Staphylococcus aureus with minimum effective concentration values of 4.0, 4.0, and 5.6 μM, respectively. Laser confocal microscopic analyses revealed that both the Arg-rich and Lys-rich histones associated with the surface of S. aureus. However, while the morphology of S. aureus treated with histone H2B appeared intact, those treated with the histones H3 and H4 closely resembled each other, and the cells were blurred. Electrophoretic mobility shift assay results revealed these histones have binding affinity to lipoteichoic acid (LTA), one of major cell surface components of Gram-positive bacteria. Scanning electron microscopic analyses demonstrated that while histone H2B elicited no obvious changes in cell morphology, histones H3 and H4 disrupted the cell membrane structure with bleb formation in a manner similar to general antimicrobial peptides. Consequently, our results suggest that bacterial cell surface LTA initially attracts both the Arg- and Lys-rich histones, but the modes of antimicrobial action of these histones are different; the former involves cell membrane disruption and the latter involves the cell integrity disruption.
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Affiliation(s)
- Shuu Morita
- Department of Biology, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan
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Yoshimura H, Ikeuchi M, Ohomori M. Cell surface-associated proteins in the filamentous cyanobacterium Anabaena sp. strain PCC 7120. Microbes Environ 2012; 27:538-43. [PMID: 23059722 PMCID: PMC4103569 DOI: 10.1264/jsme2.me12091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The cell surface senses environmental changes first and transfers signals into the cell. To understand the response to environmental changes, it is necessary to analyze cell surface components, particularly cell surface-associated proteins. We therefore investigated cell surface-associated proteins from the filamentous cyanobacterium Anabaena sp. strain PCC 7120. The cell surface-associated proteins extracted by an acidic buffer were resolved by SDS-PAGE. Eighteen proteins were identified from resolved bands by amino-terminal sequencing. Analysis of cell surface-associated proteins indicated that several proteins among them were involved in nucleic acid binding, protein synthesis, proteolytic activity and electron transfer, and other proteins were involved in the stress response.
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Affiliation(s)
- Hidehisa Yoshimura
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3–8–1 Komaba, Meguro-ku, Tokyo 153–8902, Japan.
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Qiu X, Yan X, Liu M, Han R. Genetic and proteomic characterization of rpoB mutations and their effect on nematicidal activity in Photorhabdus luminescens LN2. PLoS One 2012; 7:e43114. [PMID: 22912803 PMCID: PMC3422287 DOI: 10.1371/journal.pone.0043114] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Accepted: 07/17/2012] [Indexed: 11/18/2022] Open
Abstract
Rifampin resistant (Rif(R)) mutants of the insect pathogenic bacterium Photorhabdus luminescens LN2 from entomopathogenic nematode Heterorhabditis indica LN2 were genetically and proteomically characterized. The Rif(R) mutants showed typical phase one characters of Photorhabdus bacteria, and insecticidal activity against Galleria mellonella larvae, but surprisingly influenced their nematicidal activity against axenic infective juveniles (IJs) of H. bacteriophora H06, an incompatible nematode host. 13 out of 34 Rif(R) mutants lost their nematicidal activity against H06 IJs but supported the reproduction of H06 nematodes. 7 nematicidal-producing and 7 non-nematicidal-producing Rif(R) mutants were respectively selected for rpoB sequence analysis. rpoB mutations were found in all 14 Rif(R) mutants. The rpoB (P564L) mutation was found in all 7 mutants which produced nematicidal activity against H06 nematodes, but not in the mutants which supported H06 nematode production. Allelic exchange assays confirmed that the Rif-resistance and the impact on nematicidal activity of LN2 bacteria were conferred by rpoB mutation(s). The non-nematicidal-producing Rif(R) mutant was unable to colonize in the intestines of H06 IJs, but able to colonize in the intestines of its indigenous LN2 IJs. Proteomic analysis revealed different protein expression between wild-type strain and Rif(R) mutants, or between nematicidal-producing and non nematicidal-producing mutants. At least 7 putative proteins including DsbA, HlpA, RhlE, RplC, NamB (a protein from T3SS), and 2 hypothetical proteins (similar to unknown protein YgdH and YggE of Escherichia coli respectively) were probably involved in the nematicidal activity of LN2 bacteria against H06 nematodes. This hypothesis was further confirmed by creating insertion-deletion mutants of three selected corresponding genes (the downregulated rhlE and namB, and upregulated dsbA). These results indicate that the rpoB mutations greatly influence the symbiotic association between the symbionts and their entomopathogenic nematode hosts.
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Affiliation(s)
- Xuehong Qiu
- Guangdong Entomological Institute, Guangzhou, Guangdong, China
| | - Xun Yan
- Guangdong Entomological Institute, Guangzhou, Guangdong, China
| | - Mingxing Liu
- Guangdong Entomological Institute, Guangzhou, Guangdong, China
| | - Richou Han
- Guangdong Entomological Institute, Guangzhou, Guangdong, China
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CovR alleviates transcriptional silencing by a nucleoid-associated histone-like protein in Streptococcus mutans. J Bacteriol 2012; 194:2050-61. [PMID: 22343292 DOI: 10.1128/jb.06812-11] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Streptococcus mutans, the global response regulator CovR plays an important role in biofilm formation, stress tolerance response, and caries production. We have previously demonstrated that CovR activates a large gene cluster, which is a part of a genomic island, TnSmu2. In this article, we have further characterized CovR at the molecular level to understand the gene activation mechanism. Toward this end, we mapped the transcription start site of the operon that lies upstream of the SMU.1348 gene (P(SMU.1348)), the first gene of the cluster. We constructed a transcriptional reporter fusion and showed that CovR induces expression from P(SMU.1348). We also demonstrated that purified CovR protects the sequence surrounding the -10 region of P(SMU.1348). In an in vitro transcription assay, we showed that histone-like protein (HLP), a homologue of Escherichia coli HU protein, represses transcription from P(SMU.1348). In vivo overexpression of HLP in trans also represses transcription from P(SMU.1348). Addition of CovR to the HLP-repressed P(SMU.1348) resulted in increased transcription from the promoter, suggesting a role for CovR in countering HLP silencing. Moreover, addition of SMU.1349, a transcriptional activator of the operon, to the in vitro assay further stimulated the transcription. Based on our in vivo and in vitro results, we propose a model for transcriptional activation of the operon.
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Schwartz J, Pavlova S, Kolokythas A, Lugakingira M, Tao L, Miloro M. Streptococci-human papilloma virus interaction with ethanol exposure leads to keratinocyte damage. J Oral Maxillofac Surg 2011; 70:1867-79. [PMID: 22079067 DOI: 10.1016/j.joms.2011.08.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 08/02/2011] [Accepted: 08/03/2011] [Indexed: 11/16/2022]
Abstract
PURPOSE Ethanol, human papilloma virus (HPV), and poor oral hygiene are risk factors that have been attributed to oral carcinogenesis. Streptococci sp and HPV infections are common in the head and neck, often associated with sexual activity. Although HPV is linked to head and neck squamous cell carcinoma, it is unclear whether there is a similar role for Streptococci sp. This cell study examines whether Streptococci sp and HPV-16 with exposure to ethyl alcohol (ETOH) can act as cofactors in the malignant transformation of oral keratinocytes. MATERIALS AND METHODS ETOH (0.1%-20% vol/vol) was used to investigate Streptococci sp attachment with immortalized E6-expressing HPV/HOK-16B cells, human oral buccal keratinocytes, and foreskin keratinocytes. Streptococci sp (Streptococci mutans [LT11]) and various strains of acetaldehyde (AA) producer and nonproducer Streptococcus salivarius (110-1, 109-2, 101-7, and 107-1) and a lactic acid producer bacterium, Lactobacillus rhamnosus (24-1 and 25-2), were examined for interactions with keratinocytes by use of a green dye (percent of cells with colonies after 24 hours). Carcinogens, AA, malondialdehyde, DNA damage, and proliferation (5'-bromo-2-deoxyuridine) among keratinocytes were also quantified. RESULTS AA and malondialdehyde production from permissible Streptococci sp significantly increased with attachment to keratinocytes, whereas L rhamnosus did not significantly attach to keratinocytes. This attachment was associated with enhanced levels of AA adduct formation, proliferation (5'-bromo-2-deoxyuridine incorporation), and enhanced migration through integrin-coated basement membrane by HPV oral keratinocytes, which are characteristics of a malignant phenotype. CONCLUSIONS These cell studies suggest that oral Streptococci sp and HPV (HPV-16) cooperate to transform oral keratinocytes after low-level ETOH (1%) exposure. These results appear to suggest a significant clinical interaction, but further validation is warranted.
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Affiliation(s)
- Joel Schwartz
- Department of Oral Medicine and Diagnostic Sciences, and Member, University of Illinois Cancer Center, College of Dentistry, University of Illinois at Chicago, Chicago, IL 60612, USA.
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Anuchin AM, Goncharenko AV, Demidenok OI, Kaprelyants AS. Histone-like proteins of bacteria (review). APPL BIOCHEM MICRO+ 2011. [DOI: 10.1134/s0003683811060020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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21
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Livezey J, Perez L, Suciu D, Yu X, Robinson B, Bush D, Merrill G. Analysis of group A Streptococcus gene expression in humans with pharyngitis using a microarray. J Med Microbiol 2011; 60:1725-1733. [PMID: 21799202 DOI: 10.1099/jmm.0.022939-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Pharyngitis caused by group A streptococci (GAS) is one of the most common infections around the world. However, relatively little is known about which genes are expressed and which genes regulate expression during acute infection. Due to their ability to provide genome-wide views of gene expression at one time, microarrays are increasingly being incorporated in GAS research. In this study, a novel electrochemical detection-based microarray was used to identify gene expression patterns among humans with culture-confirmed GAS pharyngitis. Using 14 samples (11 GAS-positive and three GAS-negative) obtained from subjects seen at the Brooke Army Medical Center paediatric clinic, this study demonstrated two different clusters of gene expression patterns. One cluster expressed a larger number of genes related to phages, immune-system evasion and survival among competing oral flora, signifying a potentially more virulent pattern of gene expression. The other cluster showed a greater number of genes related to nutrient acquisition and protein expression. This in vivo genome-wide analysis of GAS gene expression in humans with pharyngitis evaluated global gene expression in terms of virulence factors.
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Affiliation(s)
- Jeffrey Livezey
- Department of Clinical Investigations, Brooke Army Medical Center, 3400 Rawley E. Chambers Ave, Suite A, San Antonio, TX 78234, USA
| | - Luis Perez
- Department of Clinical Investigations, Brooke Army Medical Center, 3400 Rawley E. Chambers Ave, Suite A, San Antonio, TX 78234, USA
| | - Dominic Suciu
- Department of Clinical Investigations, Brooke Army Medical Center, 3400 Rawley E. Chambers Ave, Suite A, San Antonio, TX 78234, USA
| | - Xin Yu
- Department of Clinical Investigations, Brooke Army Medical Center, 3400 Rawley E. Chambers Ave, Suite A, San Antonio, TX 78234, USA
| | - Brian Robinson
- Department of Clinical Investigations, Brooke Army Medical Center, 3400 Rawley E. Chambers Ave, Suite A, San Antonio, TX 78234, USA
| | - David Bush
- Department of Clinical Investigations, Brooke Army Medical Center, 3400 Rawley E. Chambers Ave, Suite A, San Antonio, TX 78234, USA
| | - Gerald Merrill
- Department of Clinical Investigations, Brooke Army Medical Center, 3400 Rawley E. Chambers Ave, Suite A, San Antonio, TX 78234, USA
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Eison TM, Ault BH, Jones DP, Chesney RW, Wyatt RJ. Post-streptococcal acute glomerulonephritis in children: clinical features and pathogenesis. Pediatr Nephrol 2011; 26:165-80. [PMID: 20652330 DOI: 10.1007/s00467-010-1554-6] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 04/16/2010] [Accepted: 04/19/2010] [Indexed: 12/15/2022]
Abstract
Post-streptococcal acute glomerulonephritis (PSAGN) is one of the most important and intriguing conditions in the discipline of pediatric nephrology. Although the eventual outcome is excellent in most cases, PSAGN remains an important cause of acute renal failure and hospitalization for children in both developed and underdeveloped areas. The purpose of this review is to describe both the typical and less common clinical features of PSAGN, to outline the changes in the epidemiology of PSAGN over the past 50 years, and to explore studies on the pathogenesis of the condition with an emphasis on the search for the elusive nephritogenic antigen.
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Affiliation(s)
- T Matthew Eison
- Division of Pediatric Nephrology, Department of Pediatrics, University of Tennessee Health Science Center, and Children's Foundation Research Center at Le Bonheur Children's Medical Center, 50 North Dunlap, Memphis, TN 38103, USA
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Surface-exposed histone-like protein a modulates adherence of Streptococcus gallolyticus to colon adenocarcinoma cells. Infect Immun 2009; 77:5519-27. [PMID: 19752027 DOI: 10.1128/iai.00384-09] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Streptococcus gallolyticus (formerly known as Streptococcus bovis biotype I) is a low-grade opportunistic pathogen which is considered to be associated with colon cancer. It is thought that colon polyps or tumors are the main portal of entry for this bacterium and that heparan sulfate proteoglycans (HSPGs) at the colon tumor cell surface are involved in bacterial adherence during the first stages of infection. In this study, we have shown that the histone-like protein A (HlpA) of S. gallolyticus is a genuine anchorless bacterial surface protein that binds to lipoteichoic acid (LTA) of the gram-positive cell wall in a growth phase-dependent manner. In addition, HlpA was shown to be one of the major heparin-binding proteins of S. gallolyticus able to bind to the HSPG-expressing colon tumor cell lines HCT116 and HT-29. Strikingly, although wild-type levels of HlpA appeared to contribute to adherence, coating of additional HlpA at the bacterial surface resulted in reduced binding to colon tumor cells. This may be explained by the fact that heparan sulfate and LTA compete for the same binding site in HlpA. Altogether, this study implies that HlpA serves as a fine-tuning factor for bacterial adherence.
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Liu D, Yumoto H, Murakami K, Hirota K, Kayama S, Taniguchi T, Yamamoto A, Ono T, Matsuo T, Miyake Y. Heterologous expression ofa histone-like protein from Streptococcus intermedius in Escherichia coli alters the nucleoid structure and inhibits the growth of E. coli. FEMS Microbiol Lett 2008; 288:68-75. [PMID: 18761672 DOI: 10.1111/j.1574-6968.2008.01327.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Escherichia coli failed to survive after transformation with a Streptococcus intermedius histone-like protein gene (Si-hlp) and its promoter-harbored plasmid. The promoter function of Si-hlp in E. coli was determined using enhanced green fluorescence protein (egfp) gene as a reporter. The inhibitory effect of Si-HLP on E. coli viability was verified by a tetracycline-inducible gene expression system. Further study suggested that Si-HLP may alter the bacterial nucleoid structure, leading to the growth inhibition of E. coli.
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Liu D, Yumoto H, Murakami K, Hirota K, Ono T, Nagamune H, Kayama S, Matsuo T, Miyake Y. The essentiality and involvement of Streptococcus intermedius histone-like DNA-binding protein in bacterial viability and normal growth. Mol Microbiol 2008; 68:1268-82. [PMID: 18410499 DOI: 10.1111/j.1365-2958.2008.06232.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Streptococcus intermedius histone-like DNA-binding protein (Si-HLP) is a homodimeric protein and, conserved with Escherichia coli HU, a well-documented nucleoid-associated protein (NAP). In E. coli, HU plays important roles as both structural and regulatory factors, but it is not essential for E. coli viability. Streptococcal HLP has been found to bind host cells and induce cytokine production, but its physiological role remains poorly defined. In the present study, using gene insertion knockout and tetracycline-regulated antisense RNA expression techniques, we determined whether Si-HLP is essential for bacterial viability and normal growth in S. intermedius. The Si-HLP-downregulated S. intermedius strain showed alterations in its morphology and surface properties. Downregulation of Si-HLP led to an expanded nucleoid to fill the intracellular space. Transcription levels of several genes, including virulence-associated factors, were found to be activated or repressed in the antisense Si-hlp RNA-expressing strain by real-time PCR and reverse-transcription PCR. Collectively, these data suggest that Si-HLP serves as an essential NAP governing the nucleoid architecture and controlling the gene transcription profile in S. intermedius.
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Affiliation(s)
- Dali Liu
- Department of Microbiology, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kumamoto-cho, Tokushima 770-8504, Japan
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Haruta I, Kikuchi K, Hashimoto E, Kato H, Hirota K, Kobayashi M, Miyake Y, Uchiyama T, Yagi J, Shiratori K. A possible role of histone-like DNA-binding protein of Streptococcus intermedius in the pathogenesis of bile duct damage in primary biliary cirrhosis. Clin Immunol 2008; 127:245-51. [PMID: 18337173 DOI: 10.1016/j.clim.2008.01.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2007] [Revised: 12/10/2007] [Accepted: 01/11/2008] [Indexed: 10/22/2022]
Abstract
Bacterial infection has become a focus of attention in the pathogenesis of primary biliary cirrhosis (PBC). It was reported that anti-histone autoantibody was detected in PBC, suggesting that bacterial histone-like DNA-binding protein (HLP) may be involved in the pathogenesis of PBC. To identify bacterial species in PBC to confirm this possibility, serum reactivity to bacterial cells was studied by ELISA. The IgM class Streptococcus intermedius titers were significantly higher in PBC than chronic hepatitis due to hepatitis C virus (CH-C) and healthy subjects. Among the streptococci, S. intermedius was selected for further study. The antigenic peptide of S. intermedius of HLP was synthesized to examine the serum reactivity to Si-HLP. IgM class anti-Si-HLP peptide titers were significantly higher in PBC. Immunoreactivity to anti-Si-HLP was detected in the cytoplasm of biliary epithelial cells and inflammatory cells in the portal area in PBC patients' livers. Streptococci, especially S. intermedius, might play a key role in the pathogenesis of PBC, possibly involving HLP.
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Affiliation(s)
- Ikuko Haruta
- Department of Medicine and Gastroenterology, Tokyo Women's Medical University, Japan.
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27
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Liu D, Yumoto H, Hirota K, Murakami K, Takahashi K, Hirao K, Matsuo T, Ohkura K, Nagamune H, Miyake Y. Histone-like DNA binding protein of Streptococcus intermedius induces the expression of pro-inflammatory cytokines in human monocytes via activation of ERK1/2 and JNK pathways. Cell Microbiol 2007; 10:262-76. [PMID: 17883418 DOI: 10.1111/j.1462-5822.2007.01040.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Streptococcus intermedius is a commensal associated with serious, deep-seated purulent infections in major organs, such as the brain and liver. Histone-like DNA binding protein (HLP) is an accessory architectural protein in a variety of bacterial cellular processes. In this study, we investigated the mechanisms of pro-inflammatory cytokine inductions in THP-1 cells by stimulation with recombinant HLP of S. intermedius (rSi-HLP). rSi-HLP stimulation-induced production of pro-inflammatory cytokines (IL-8, IL-1 beta and TNF-alpha) occurred in a time- and dose-dependent manner. In contrast with the heat-stable activity of DNA binding, the induction activity of rSi-HLP was heat-unstable. In subsequent studies, rSi-HLP acted cooperatively with lipoteichoic acid, the synthetic Toll-like receptor 2 agonist, Pam3CSK4, and the cytosolic nucleotide binding oligomerization domain 2 receptor agonist, muramyldipeptide. Furthermore, Western blot and blocking assays with specific inhibitors showed that rSi-HLP stimulation induced the activation of cell signal transduction pathways, extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK). In addition to its physiological role in bacterial growth through DNA binding, these results indicate that Si-HLP can trigger a cascade of events that induce pro-inflammatory responses via ERK1/2 and JNK signal pathways, and suggest that bacterial HLP may contribute to the activation of host innate immunity during bacterial infection.
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Affiliation(s)
- Dali Liu
- Department of Microbiology, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15, Kuramoto-cho, Tokushima 770-8504, Japan
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28
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Rodríguez-Iturbe B, Batsford S. Pathogenesis of poststreptococcal glomerulonephritis a century after Clemens von Pirquet. Kidney Int 2007; 71:1094-104. [PMID: 17342179 DOI: 10.1038/sj.ki.5002169] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Considerable insight has been gained into the etiopathogenesis of poststreptococcal glomerulonephritis since the landmark theoretical construct of Clemens von Pirquet postulated that disease-causing immune complexes were responsible for the nephritis that followed scarlet fever. Over the years, molecular mimicry between streptococcal products and renal components, autoimmune reactivity and several streptococcal antigens have been extensively studied. Recent investigations assign a critical role to both in situ formation and deposition of circulating immune complexes that would trigger a variety of effector mechanisms. Glomerular plasmin-binding activity of streptococcal glyceraldehyde-3-phosphate-dehydrogenase may play a role in nephritogenicity and streptococcal pyrogenic exotoxin B and its zymogen precursor may be the long-sought nephritogenic antigen.
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Affiliation(s)
- B Rodríguez-Iturbe
- Instituto Venezolano de Investigaciones Científicas (IVIC-Zulia), Hospital Universitario de Maracaibo, Centro de Investigaciones Biomédicas, Maracaibo, Venezuela.
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Tjalsma H, Lasonder E, Schöller-Guinard M, Swinkels DW. Shotgun immunoproteomics to identify disease-associated bacterial antigens: Application to human colon cancer. Proteomics Clin Appl 2007. [DOI: 10.1002/prca.200601018] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Nair GB, Ramamurthy T, Bhattacharya SK, Dutta B, Takeda Y, Sack DA. Global dissemination of Vibrio parahaemolyticus serotype O3:K6 and its serovariants. Clin Microbiol Rev 2007; 20:39-48. [PMID: 17223622 PMCID: PMC1797631 DOI: 10.1128/cmr.00025-06] [Citation(s) in RCA: 390] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vibrio parahaemolyticus is recognized as a cause of food-borne gastroenteritis, particularly in the Far East, where raw seafood consumption is high. An unusual increase in admissions of V. parahaemolyticus cases was observed at the Infectious Diseases Hospital in Calcutta, a city in the northeastern part of India, beginning February 1996. Analysis of the strains revealed that a unique serotype, O3:K6, not previously isolated during the surveillance in Calcutta accounted for 50 to 80% of the infections in the following months. After this report, O3:K6 isolates identical to those isolated in Calcutta were reported from food-borne outbreaks and from sporadic cases in Bangladesh, Chile, France, Japan, Korea, Laos, Mozambique, Peru, Russia, Spain, Taiwan, Thailand, and the United States. Other serotypes, such as O4:K68, O1:K25, and O1:KUT (untypeable), that had molecular characteristics identical to that of the O3:K6 serotype were subsequently documented. These serotypes appeared to have diverged from the O3:K6 serotype by alteration of the O:K antigens and were defined as "serovariants" of the O3:K6 isolate. O3:K6 and its serovariants have now spread into Asia, America, Africa, and Europe. This review traces the genesis, virulence features, molecular characteristics, serotype variants, environmental occurrence, and global spread of this unique clone of V. parahaemolyticus.
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Affiliation(s)
- G Balakrish Nair
- Enteric Microbiology Unit, Laboratory Sciences Division, ICDDR,B: Center for Health and Population Research, Mohakhali, Dhaka 1212, Bangladesh.
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31
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Tjalsma H, Schöller-Guinard M, Lasonder E, Ruers TJ, Willems HL, Swinkels DW. Profiling the humoral immune response in colon cancer patients: diagnostic antigens from Streptococcus bovis. Int J Cancer 2006; 119:2127-35. [PMID: 16841330 DOI: 10.1002/ijc.22116] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The human bowel contains a large and dynamic bacterial population that is not only essential for intestinal health, but also critical for the development of diseases such as cancer. In this respect, the Gram-positive bacterium Streptococcus bovis has been associated with colon cancer for many years. To investigate the clinical importance of this association, an immunocapture mass spectrometry assay was developed that can generate infection-related protein profiles. The composition of these profiles is governed by the capture of specific antigens by serum antibodies from colon cancer patients. This assay showed that S. bovis antigen profiles could distinguish 11 out of 12 colon cancer patients from 8 control subjects, whereas antigen profiles derived from the gut bacterium Escherichia coli were not diagnostic for colon cancer. Moreover, S. bovis antigen profiles were also detected in polyp patients, indicating that infection with this bacterium does occur early during carcinogenesis. Highly accurate tandem mass spectrometry was used to identify one of the diagnostic antigens as a surface-exposed heparin-binding protein, which might be involved in attachment of S. bovis to tumor cells. Together, these findings corroborate the hypothesis that colonic lesions provide a specific niche for S. bovis, resulting in tumor-associated "silent" infections. These infections, however, only become apparent in colon cancer patients with a compromised immune system (bacteremia) or coincidental cardiac valve lesions (endocarditis). This makes profiling of the humoral immune response against "silent" S. bovis infections a promising diagnostic tool for the early detection of human colon cancer, which is crucial for the effective treatment of this disease.
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Affiliation(s)
- Harold Tjalsma
- Department of Clinical Chemistry, Radboud University Nijmegen-Medical Centre, Nijmegen, The Netherlands.
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32
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Steggles JR, Wang J, Ellar DJ. Discovery of Bacillus thuringiensis virulence genes using signature-tagged mutagenesis in an insect model of septicaemia. Curr Microbiol 2006; 53:303-10. [PMID: 16941243 DOI: 10.1007/s00284-006-0037-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Accepted: 03/08/2006] [Indexed: 10/24/2022]
Abstract
Transposon Tn917 was used to identify Bacillus thuringiensis genes required for virulence and survival in a Manduca sexta (tobacco hornworm) septicaemia model. Uniquely tagged transposons, n = 72, were constructed and used to generate 1152 insertion mutants. Sixteen pools of 72 mutants were screened in the infection model, and 12 virulence-attenuated mutants were unable to survive the infection. Analysis of the mutated DNA sequences implicated an arsR family transcriptional regulator, a histone-like DNA-binding protein, a transposon, and several sequences of unknown function in B. thuringiensis pathogenesis.
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Affiliation(s)
- James R Steggles
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, England
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Jin H, Pancholi V. Identification and Biochemical Characterization of a Eukaryotic-type Serine/Threonine Kinase and its Cognate Phosphatase in Streptococcus pyogenes: Their Biological Functions and Substrate Identification. J Mol Biol 2006; 357:1351-72. [PMID: 16487973 DOI: 10.1016/j.jmb.2006.01.020] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2005] [Revised: 01/09/2006] [Accepted: 01/11/2006] [Indexed: 10/25/2022]
Abstract
A eukaryotic-type signaling system in group A Streptococcus (GAS) was identified and characterized. This system comprises primarily the products of two co-transcribed genes, a eukaryotic-type Ser/Thr kinase (SP-STK) and phosphatase (SP-STP) and their endogenous substrate histone-like protein (SP-HLP). Enzyme activities of SP-STK and SP-STP primarily depended on Mn(2+). The site on the substrate for reversible phosphorylation by these enzymes was found to be only the threonine residue. Using specific antibodies generated against these proteins, SP-STK was found to be membrane-associated with its N-terminal kinase domain facing the cytoplasm and its C-terminal repeat domain outside the membrane and cell-wall associated. Further, SP-STP, primarily a cytoplasmic protein, was found to be a major secretory protein of GAS and essential for bacterial survival. Three isogenic mutants, lacking either the entire SP-STK, or one of its two domains, were found displaying distinct pleiotropic effects on growth, colony morphology, cell division/septation, surface protein/virulence factor expression, bacterial ability to adhere to and invade human pharyngeal cells, and resist phagocytosis by human neutrophils. In addition to these properties, the ability of these three proteins to modulate the expression of the major virulence factors, the M protein and the capsule, indicates that these proteins are structurally and functionally distinct from the kinases and phosphatases described in other microorganisms and play a key role in GAS pathogenesis.
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Affiliation(s)
- Hong Jin
- Laboratory of Bacterial Pathogenesis, Department of Pathology, Ohio State University College of Medicine and Public Health, 288A, Tzgournis Medical Research Facility, 420 W 12th Avenue, Columbus, OH 43210-1214, USA
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34
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Terao Y, Yamaguchi M, Hamada S, Kawabata S. Multifunctional glyceraldehyde-3-phosphate dehydrogenase of Streptococcus pyogenes is essential for evasion from neutrophils. J Biol Chem 2006; 281:14215-23. [PMID: 16565520 DOI: 10.1074/jbc.m513408200] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Streptococcus pyogenes is an important pathogen that causes pharyngitis, sepsis, and rheumatic fever. Cell-associated streptococcal C5a peptidase (ScpA) protects S. pyogenes from phagocytosis and has been suggested to interrupt host defenses by enzymatically cleaving complement C5a, a major factor in the accumulation of neutrophils at sites of infection. How S. pyogenes recognizes and binds to C5a, however, is unclear. We detected a C5a-binding protein in 8 M urea extracts of S. pyogenes by ligand blotting using biotinylated C5a. Searching of genome databases showed that the C5a-binding protein is identical to the streptococcal plasmin receptor (Plr), also known as streptococcal surface dehydrogenase (SDH) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). In the present study we identified a novel function of this multifunctional protein. Western blotting and immunofluorescence microscopy with anti-Plr/SDH/GAPDH showed that Plr/SDH/GAPDH is located on the bacterial surface and released into the culture supernatant. Next, we examined whether the streptococcal Plr/SDH/GAPDH inhibits the biological effects of C5a on human neutrophils. We found that soluble Plr/SDH/GAPDH inhibits C5a-activated chemotaxis and H2O2 production. Furthermore, our results suggested that soluble Plr/SDH/GAPDH captures C5a, inhibiting its chemotactic function. Also, cell-associated Plr/SDH/GAPDH and ScpA were both necessary for the cleavage of C5a on the bacterial surface. Together, these results indicate that the multifunctional protein Plr/SDH/GAPDH has additional functions that help S. pyogenes escape detection by the host immune system.
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Affiliation(s)
- Yutaka Terao
- Department of Oral and Molecular Microbiology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
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35
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Yu HB, Zhang YL, Lau YL, Yao F, Vilches S, Merino S, Tomas JM, Howard SP, Leung KY. Identification and characterization of putative virulence genes and gene clusters in Aeromonas hydrophila PPD134/91. Appl Environ Microbiol 2005; 71:4469-77. [PMID: 16085838 PMCID: PMC1183340 DOI: 10.1128/aem.71.8.4469-4477.2005] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Aeromonas hydrophila is a gram-negative opportunistic pathogen of animals and humans. The pathogenesis of A. hydrophila is multifactorial. Genomic subtraction and markers of genomic islands (GIs) were used to identify putative virulence genes in A. hydrophila PPD134/91. Two rounds of genomic subtraction led to the identification of 22 unique DNA fragments encoding 19 putative virulence factors and seven new open reading frames, which are commonly present in the eight virulence strains examined. In addition, four GIs were found, including O-antigen, capsule, phage-associated, and type III secretion system (TTSS) gene clusters. These putative virulence genes and gene clusters were positioned on a physical map of A. hydrophila PPD134/91 to determine their genetic organization in this bacterium. Further in vivo study of insertion and deletion mutants showed that the TTSS may be one of the important virulence factors in A. hydrophila pathogenesis. Furthermore, deletions of multiple virulence factors such as S-layer, serine protease, and metalloprotease also increased the 50% lethal dose to the same level as the TTSS mutation (about 1 log) in a blue gourami infection model. This observation sheds light on the multifactorial and concerted nature of pathogenicity in A. hydrophila. The large number of putative virulence genes identified in this study will form the basis for further investigation of this emerging pathogen and help to develop effective vaccines, diagnostics, and novel therapeutics.
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Affiliation(s)
- H B Yu
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Science Drive 4, Singapore 117543, Republic of Singapore
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36
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Okura M, Osawa R, Arakawa E, Terajima J, Watanabe H. Identification of Vibrio parahaemolyticus pandemic group-specific DNA sequence by genomic subtraction. J Clin Microbiol 2005; 43:3533-6. [PMID: 16000499 PMCID: PMC1169085 DOI: 10.1128/jcm.43.7.3533-3536.2005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A genomic subtraction between a pandemic Vibrio parahaemolyticus and a nonpandemic strain that seemed to be clonally related was performed. A subtractive DNA fragment was identified to be a part of a 16-kbp insertion sequence which was present in almost all pandemic strains but not in nonpandemic strains tested.
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Affiliation(s)
- Masatoshi Okura
- Department of Bioscience, Graduate School of Science and Technology, Kobe University, Rokko-dai 1-1, Nada-ku, Kobe City, Japan 657-8501
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37
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Waters CM, Hirt H, McCormick JK, Schlievert PM, Wells CL, Dunny GM. An amino-terminal domain of Enterococcus faecalis aggregation substance is required for aggregation, bacterial internalization by epithelial cells and binding to lipoteichoic acid. Mol Microbiol 2004; 52:1159-71. [PMID: 15130132 DOI: 10.1111/j.1365-2958.2004.04045.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Aggregation substance (AS), a plasmid-encoded surface protein of Enterococcus faecalis, plays important roles in virulence and antibiotic resistance transfer. Previous studies have suggested that AS-mediated aggregation of enterococcal cells could involve the binding of this protein to cell wall lipoteichoic acid (LTA). Here, a method to purify an undegraded form of Asc10, the AS of the plasmid pCF10, is described. Using this purified protein, direct binding of Asc10 to purified E. faecalis LTA was demonstrated. Equivalent binding of Asc10 to LTA purified from INY3000, an E. faecalis strain that is incapable of aggregation, was also observed. Surprisingly, mutations in a previously identified aggregation domain from amino acids 473 to 683 that abolished aggregation had no effect on LTA binding. In frame deletion analysis of Asc10 was used to identify a second aggregation domain located in the N-terminus of the protein from amino acids 156 to 358. A purified Asc10 mutant protein lacking this domain showed reduced LTA binding, while a purified N-terminal fragment from amino acids 44-331 had high LTA binding. Like the previously described aggregation domain, the newly identified Asc10((156-358)) aggregation domain was also required for efficient internalization of E. faecalis into HT-29 enterocytes. Thus, Asc10 possess two distinct domains required for aggregation and eukaryotic cell internalization: an N-terminal domain that promotes binding to LTA and a second domain located near the middle of the protein.
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Affiliation(s)
- Christopher M Waters
- Department of Microbiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
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38
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Neuhaus FC, Baddiley J. A continuum of anionic charge: structures and functions of D-alanyl-teichoic acids in gram-positive bacteria. Microbiol Mol Biol Rev 2003; 67:686-723. [PMID: 14665680 PMCID: PMC309049 DOI: 10.1128/mmbr.67.4.686-723.2003] [Citation(s) in RCA: 723] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Teichoic acids (TAs) are major wall and membrane components of most gram-positive bacteria. With few exceptions, they are polymers of glycerol-phosphate or ribitol-phosphate to which are attached glycosyl and D-alanyl ester residues. Wall TA is attached to peptidoglycan via a linkage unit, whereas lipoteichoic acid is attached to glycolipid intercalated in the membrane. Together with peptidoglycan, these polymers make up a polyanionic matrix that functions in (i) cation homeostasis; (ii) trafficking of ions, nutrients, proteins, and antibiotics; (iii) regulation of autolysins; and (iv) presentation of envelope proteins. The esterification of TAs with D-alanyl esters provides a means of modulating the net anionic charge, determining the cationic binding capacity, and displaying cations in the wall. This review addresses the structures and functions of D-alanyl-TAs, the D-alanylation system encoded by the dlt operon, and the roles of TAs in cell growth. The importance of dlt in the physiology of many organisms is illustrated by the variety of mutant phenotypes. In addition, advances in our understanding of D-alanyl ester function in virulence and host-mediated responses have been made possible through targeted mutagenesis of dlt. Studies of the mechanism of D-alanylation have identified two potential targets of antibacterial action and provided possible screening reactions for designing novel agents targeted to D-alanyl-TA synthesis.
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Affiliation(s)
- Francis C Neuhaus
- Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, Illinois 60208. USA.
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Antikainen J, Anton L, Sillanpää J, Korhonen TK. Domains in the S-layer protein CbsA of Lactobacillus crispatus involved in adherence to collagens, laminin and lipoteichoic acids and in self-assembly. Mol Microbiol 2002; 46:381-94. [PMID: 12406216 DOI: 10.1046/j.1365-2958.2002.03180.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The protein regions in the S-layer protein CbsA of Lactobacillus crispatus JCM 5810, needed for binding to collagens and laminin, anchoring to bacterial cell wall, as well as self-assembly, were mapped by deletion analysis of His-tagged peptides isolated from Escherichia coli and by heterologous expression on Lactobacillus casei. Mature CbsA is 410 amino acids long, and stepwise genetic truncation at both termini revealed that the region 32-271 carries the infor-mation for self-assembly of CbsA into a periodic structure. The lactobacillar S-layer proteins exhibit sequence variation in their assembly domain, but the border regions 30-34 and 269-274 in CbsA are conserved in valine-rich short sequences. Short deletions or substitutions at these regions affected the morphology of His-CbsA polymers, which varied from sheet-like to cylindrical tubular polymers, and further truncation beyond the DNA encoding residues 32 and 271 leads to a non-periodic aggregation. The self-assembly of the truncated peptides, as seen by electron microscopy, was correlated with their behaviour in a cross-linking study. The shorter peptides not forming a regular polymer were observed by the cross-linking study and mass spectrometry to form dimers, trimers and tetramers, whereas the other peptides were cross-linked to large multimers only. Binding of solubilized type I and IV collagens was observed with the His-CbsA peptides 1-274 and 31-287, but not with the smaller peptides regardless of their ability to form regular polymers. Strain JCM 5810 also adheres to immobilized laminin and, in order to analyse the possible laminin binding by CbsA, cbsA and its fragments were expressed on the surface of L. casei. Expression of the CbsA peptides 1-274, 1-287, 28-287 and 31-287 on L. casei conferred adhesiveness to both laminin and collagen immobilized on glass as well as to laminin- and collagen-containing regions in chicken colon and ileum. The C-terminal peptides 251-410 and 288-410 bound to L. crispatus JCM 5810 cells from which the S-layer had been depleted by chemical extraction, whereas no binding was seen with the His-CbsA peptides 1-250 or 1-269 or to cells with an intact S-layer. The His-CbsA peptides 251-410 and 288-410 bound to teichoic acids of several bacterial species. The results show that CbsA is an adhesive complex with an N-terminal assembly domain exhibiting affinity for pericellular tissue components and a cationic C-terminal domain binding to negatively charged cell wall components.
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Affiliation(s)
- Jenni Antikainen
- Department of Biosciences, University of Helsinki, Helsinki, Finland
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40
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Jonquières R, Pizarro-Cerdá J, Cossart P. Synergy between the N- and C-terminal domains of InlB for efficient invasion of non-phagocytic cells by Listeria monocytogenes. Mol Microbiol 2001; 42:955-65. [PMID: 11737639 DOI: 10.1046/j.1365-2958.2001.02704.x] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
InlB is a Listeria monocytogenes protein promoting entry in non-phagocytic cells, and has been shown recently to activate the hepatocyte growth factor receptor (HGFR or Met). The N-terminal domain of InlB (LRRs) binds and activates Met, whereas the C-terminal domain of InlB (GW modules) mediates loose attachment of InlB to the listerial surface. As HGF activation of Met is tightly controlled by glycosaminoglycans (GAGs), we tested if GAGs also modulate the Met-InlB interactions. We show that InlB-dependent invasion of non-phagocytic cells decreases up to 10 times in the absence of GAGs, and that soluble heparin releases InlB from the bacterial surface and promotes its clustering. Furthermore, we demonstrate that InlB binds cellular GAGs by its GW modules, and that this interaction is required for efficient InlB-mediated invasion. Therefore, GW modules have an unsuspected dual function: they attach InlB to the bacterial surface and enhance entry triggered by the LRRs domain. Our results thus provide the first evidence for a synergy between two host factor-binding domains of a bacterial invasion protein, and reinforce similarities between InlB and mammalian growth factors.
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Affiliation(s)
- R Jonquières
- Unité des Interactions Bactéries-Cellules, Institut Pasteur, 75724 Paris Cedex 15, France
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41
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Moreno AJ, Fontes M, Murillo FJ. ihfA gene of the bacterium Myxococcus xanthus and its role in activation of carotenoid genes by blue light. J Bacteriol 2001; 183:557-69. [PMID: 11133949 PMCID: PMC94911 DOI: 10.1128/jb.183.2.557-569.2001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Myxococcus xanthus responds to blue light by producing carotenoids. Several regulatory genes are known that participate in the light action mechanism, which leads to the transcriptional activation of the carotenoid genes. We had already reported the isolation of a carotenoid-less, Tn5-induced strain (MR508), whose mutant site was unlinked to the indicated regulatory genes. Here, we show that OmegaMR508::Tn5 affects all known light-inducible promoters in different ways. It blocks the activation of two of them by light but makes the activity of a third one light independent. The OmegaMR508 locus has been cloned and sequenced. The mutation had occurred at the promoter of a gene we propose is the M. xanthus ortholog of ihfA. This encodes the alpha subunit of the histone-like integration host factor protein. An in-frame deletion within ihfA causes the same effects as the OmegaMR508::Tn5 insertion. Like other IhfA proteins, the deduced amino acid sequence of M. xanthus IhfA shows much similarity to HU, another histone-like protein. Sequence comparison data, however, and the finding that the M. xanthus gene is preceded by gene pheT, as happens in other gram-negative bacteria, strongly argue for the proposed orthology relationship. The M. xanthus ihfA gene shows some unusual features, both from structural and physiological points of view. In particular, the protein is predicted to have a unique, long acidic extension at the carboxyl terminus, and it appears to be necessary for normal cell growth and even vital for a certain wild-type strain of M. xanthus.
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Affiliation(s)
- A J Moreno
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain
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42
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Lei B, Mackie S, Lukomski S, Musser JM. Identification and immunogenicity of group A Streptococcus culture supernatant proteins. Infect Immun 2000; 68:6807-18. [PMID: 11083799 PMCID: PMC97784 DOI: 10.1128/iai.68.12.6807-6818.2000] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Extracellular proteins made by group A Streptococcus (GAS) play critical roles in the pathogenesis of human infections caused by this bacterium. Although many extracellular GAS proteins have been identified and characterized, there has been no systematic analysis of culture supernatant proteins. Proteins present in the culture supernatant of strains of serotype M1 (MGAS 5005) and M3 (MGAS 315) mutants lacking production of the major extracellular cysteine protease were separated by two-dimensional gel electrophoresis and identified by amino-terminal amino acid sequencing and interrogation of available databases, including a serotype M1 genome sequence. In the aggregate, amino-terminal amino acid sequence data for 66 protein spots were generated, 53 unique sequences were obtained, and 44 distinct proteins were identified. Sixteen of the 44 proteins had apparent secretion signal sequences and 27 proteins did not. Eight of the 16 proteins with apparent secretion signal sequences have not been previously described for GAS. Antibodies against most of the apparently secreted proteins were present in sera from mice infected subcutaneously with MGAS 5005 or MGAS 315. Humans with documented GAS infections (pharyngitis, acute rheumatic fever, and severe invasive disease) also had serum antibodies reacting with many of the apparently secreted proteins, indicating that they were synthesized in the course of GAS-human interaction. The genes encoding four of the eight previously undescribed and apparently secreted culture supernatant proteins were cloned, and the proteins were overexpressed in Escherichia coli. Western blot analysis with these recombinant proteins and sera from GAS-infected mice and humans confirmed the immunogenicity of these proteins. Taken together, the data provide new information about the molecular aspects of GAS-host interactions.
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Affiliation(s)
- B Lei
- Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, USA
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43
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de Melo Marques MA, Mahapatra S, Nandan D, Dick T, Sarno EN, Brennan PJ, Vidal Pessolani MC. Bacterial and host-derived cationic proteins bind alpha2-laminins and enhance Mycobacterium leprae attachment to human Schwann cells. Microbes Infect 2000; 2:1407-17. [PMID: 11099926 DOI: 10.1016/s1286-4579(00)01294-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It has recently been demonstrated that laminin alpha2 chains present on the surface of Schwann cells are involved in the process of attachment of Mycobacterium leprae to these cells. In this study, a protein in the M. leprae cell wall that was found to be capable of binding alpha2-containing laminins (merosin) was isolated and characterized. The M. leprae laminin-binding protein was identified as a 21-kDa histone-like protein (Hlp), a highly conserved cationic protein present in other species of mycobacteria. The gene that encodes this protein was PCR amplified, cloned, and expressed, and the recombinant protein was shown to bind alpha2-laminins. More significantly, when added exogenously, Hlp was able to greatly enhance the attachment of mycobacteria to ST88-14 human Schwann cells. The capacity to bind alpha2-laminins and to enhance mycobacterial adherence to Schwann cells was also found in other cationic proteins such as host-derived histones. Moreover, mutation in the hlp gene was shown not to affect the capacity of mycobacteria to bind to ST88-14 cells, suggesting that alternative adhesins and/or pathways might be used by mycobacteria during the process of adherence to Schwann cells. The potential role of Hlp as a fortuitous virulence factor contributing to the pathogenesis of M. leprae-mediated nerve damage is discussed.
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Affiliation(s)
- M A de Melo Marques
- Laboratório de Hanseníase, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (FIOCRUZ), Av. Brasil 4365, RJ 21045-000, Rio de Janeiro, Brazil
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44
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Zhang YL, Ong CT, Leung KY. Molecular analysis of genetic differences between virulent and avirulent strains of Aeromonas hydrophila isolated from diseased fish. MICROBIOLOGY (READING, ENGLAND) 2000; 146 ( Pt 4):999-1009. [PMID: 10784058 DOI: 10.1099/00221287-146-4-999] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Aeromonas hydrophila, a normal inhabitant of aquatic environments, is an opportunistic pathogen of a variety of aquatic and terrestrial animals, including humans. A. hydrophila PPD134/91 is defined as virulent whereas PPD35/85 is defined as avirulent on the basis of their different LD50 values in fish. Suppression subtractive hybridization (SSH) was used to identify genetic differences between these two strains. Sixty-nine genomic regions of differences were absent in PPD35/85, and the DNA sequences of these regions were determined. Sixteen ORFs encoded by 23 fragments showed high homology to known proteins of other bacteria. ORFs encoded by the remaining 46 fragments were identified as new proteins of A. hydrophila, showing no significant homology to any known proteins. Among these PPD134/91-specific genes, 22 DNA fragments (21 ORFs) were present in most of the eight virulent strains studied but mostly absent in the seven avirulent strains, suggesting that they are universal virulence genes in A. hydrophila. The PPD134/91-specific genes included five known virulence factors of A. hydrophila: haemolysin (hlyA), protease (oligopeptidase A), outer-membrane protein (Omp), multidrug-resistance protein and histone-like protein (HU-2). Another 47 DNA fragments (44 ORFs) were mainly present in PPD134/91, indicating the heterogeneity among motile aeromonads. Some of these fragments encoded virulence determinants. These included genes for the synthesis of O-antigen and type II restriction/modification system. The results indicated that SSH is successful in identifying genetic differences and virulence genes among different strains of A. hydrophila.
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Affiliation(s)
- Y L Zhang
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 10 Kent Ridge Crescent, Singapore 1192601
| | - C T Ong
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 10 Kent Ridge Crescent, Singapore 1192601
| | - K Y Leung
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 10 Kent Ridge Crescent, Singapore 1192601
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45
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Zhang L, Ignatowski TA, Spengler RN, Noble B, Stinson MW. Streptococcal histone induces murine macrophages To produce interleukin-1 and tumor necrosis factor alpha. Infect Immun 1999; 67:6473-7. [PMID: 10569765 PMCID: PMC97057 DOI: 10.1128/iai.67.12.6473-6477.1999] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The histone-like protein (HlpA) is highly conserved among streptococci. After lysis of streptococci in infected tissues, HlpA can enter the bloodstream and bind to proteoglycans in the glomerular capillaries of kidneys, where it can react with antibodies or stimulate host cell receptors. Deposits of streptococcal antigens in tissues have been associated with localized acute inflammation. In this study, we measured the ability of purified HlpA (5 to 100 microg/ml), from Streptococcus mitis, to induce the production of proinflammatory cytokines by cultured, murine peritoneal macrophages. The release of tumor necrosis factor alpha (TNF-alpha) and interleukin-1 (IL-1) was time and concentration dependent and was not diminished by the presence of polymyxin B. Exposure of macrophages to a mixture of HlpA and lipoteichoic acid resulted in a synergistic response in the production of both TNF-alpha and IL-1. Stimulation with a mixture of HlpA and heparin resulted in reduced cytokine production (50% less IL-1 and 76% less TNF-alpha) compared to that by cells incubated with HlpA alone. The inclusion of antibodies specific to HlpA in macrophage cultures during stimulation with HlpA did not affect the quantity of TNF-alpha or IL-1 produced. These observations suggest that streptococcal histone may contribute to tissue injury at infection sites by promoting monocytes/macrophages to synthesize and release cytokines that initiate and exacerbate inflammation. Streptococcus pyogenes, which can infect tissues in enormous numbers, may release sufficient amounts of HlpA to reach the kidneys and cause acute poststreptococcal glomerulonephritis.
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Affiliation(s)
- L Zhang
- Department of Microbiology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York 14214, USA
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46
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Juarez ZE, Stinson MW. An extracellular protease of Streptococcus gordonii hydrolyzes type IV collagen and collagen analogues. Infect Immun 1999; 67:271-8. [PMID: 9864226 PMCID: PMC96307 DOI: 10.1128/iai.67.1.271-278.1999] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococcus gordonii is a frequent cause of infective bacterial endocarditis, but its mechanisms of virulence are not well defined. In this study, streptococcal proteases were recovered from spent chemically defined medium (CDM) and fractionated by ammonium sulfate precipitation and by ion-exchange and gel filtration column chromatography. Three proteases were distinguished by their different solubilities in ammonium sulfate and their specificities for synthetic peptides. One of the enzymes cleaved collagen analogs Gly-Pro 4-methoxy-beta-naphthylamide, 2-furanacryloyl-Leu-Gly-Pro-Ala (FALGPA), and p-phenylazobenzyloxycarbonyl-Pro-Leu-Gly-Pro-Arg (pZ-peptide) and was released from the streptococci while complexed to peptidoglycan fragments. Treatment of this protease with mutanolysin reduced its 180- to 200-kDa mass to 98 kDa without loss of enzymatic activity. The purified protease cleaved bovine gelatin, human placental type IV collagen, and the Aalpha chain of fibrinogen but not albumin, fibronectin, laminin, or myosin. Enzyme activity was inhibited by phenylmethylsulfonyl fluoride, indicating that it is a serine-type protease. Maximum production of the 98-kDa protease occurred during growth of S. gordonii CH1 in CDM containing 0.075% total amino acids at pH 7.0 with minimal aeration. Higher initial concentrations of amino acids prevented the release of the protease without reducing cell-associated enzyme levels, and the addition of an amino acid mixture to an actively secreting culture stopped further enzyme release. The purified protease was stored frozen at -20 degreesC for several months or heated at 50 degreesC for 10 min without loss of activity. These data indicate that S. gordonii produces an extracellular gelatinase/type IV collagenase during growth in medium containing minimal concentrations of free amino acids. Thus, the extracellular enzyme is a potential virulence factor in the amino acid-stringent, thrombotic, valvular lesions of bacterial endocarditis.
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Affiliation(s)
- Z E Juarez
- Center for Microbial Pathogenesis, School of Medicine and Biomedical Sciences, State University of New York at Buffalo 14214, USA
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