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Chavonet E, Gaucher M, Warneys R, Bodelot A, Heintz C, Juillard A, Cournol R, Widmalm G, Bowen JK, Hamiaux C, Brisset MN, Degrave A. Search for host defense markers uncovers an apple agglutination factor corresponding with fire blight resistance. Plant Physiol 2022; 188:1350-1368. [PMID: 34904175 PMCID: PMC8825249 DOI: 10.1093/plphys/kiab542] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 10/25/2021] [Indexed: 06/12/2023]
Abstract
Pathenogenesis-related (PR) proteins are extensively used as molecular markers to dissect the signaling cascades leading to plant defense responses. However, studies focusing on the biochemical or biological properties of these proteins remain rare. Here, we identify and characterize a class of apple (Malus domestica) PR proteins, named M. domestica AGGLUTININS (MdAGGs), belonging to the amaranthin-like lectin family. By combining molecular and biochemical approaches, we show that abundant production of MdAGGs in leaf tissues corresponds with enhanced resistance to the bacterium Erwinia amylovora, the causal agent of the disease fire blight. We also show that E. amylovora represses the expression of MdAGG genes by injecting the type 3 effector DspA/E into host cells and by secreting bacterial exopolysaccharides. Using a purified recombinant MdAGG, we show that the protein agglutinates E. amylovora cells in vitro and binds bacterial lipopolysaccharides at low pH, conditions reminiscent of the intercellular pH occurring in planta upon E. amylovora infection. We finally provide evidence that negatively charged polysaccharides, such as the free exopolysaccharide amylovoran progressively released by the bacteria, act as decoys relying on charge-charge interaction with the MdAGG to inhibit agglutination. Overall, our results suggest that the production of this particular class of PR proteins may contribute to apple innate immunity mechanisms active against E. amylovora.
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Affiliation(s)
- Erwan Chavonet
- Institut Agro, University of Angers, INRAE, IRHS, SFR QUASAV, F-49000 Angers, France
| | - Matthieu Gaucher
- Institut Agro, University of Angers, INRAE, IRHS, SFR QUASAV, F-49000 Angers, France
| | - Romain Warneys
- Institut Agro, University of Angers, INRAE, IRHS, SFR QUASAV, F-49000 Angers, France
| | - Antoine Bodelot
- Institut Agro, University of Angers, INRAE, IRHS, SFR QUASAV, F-49000 Angers, France
| | - Christelle Heintz
- Institut Agro, University of Angers, INRAE, IRHS, SFR QUASAV, F-49000 Angers, France
| | - Anthony Juillard
- Institut Agro, University of Angers, INRAE, IRHS, SFR QUASAV, F-49000 Angers, France
| | - Raphaël Cournol
- Institut Agro, University of Angers, INRAE, IRHS, SFR QUASAV, F-49000 Angers, France
| | - Göran Widmalm
- Arrhenius Laboratory, Department of Organic Chemistry, Stockholm University, S-106 91 Stockholm, Sweden
| | - Joanna K Bowen
- The New Zealand Institute for Plant and Food Research Limited, Mount Albert Research Centre, Auckland 1025, New Zealand
| | - Cyril Hamiaux
- The New Zealand Institute for Plant and Food Research Limited, Mount Albert Research Centre, Auckland 1025, New Zealand
| | - Marie-Noëlle Brisset
- Institut Agro, University of Angers, INRAE, IRHS, SFR QUASAV, F-49000 Angers, France
| | - Alexandre Degrave
- Institut Agro, University of Angers, INRAE, IRHS, SFR QUASAV, F-49000 Angers, France
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Farinholt T, Dinh C, Kuspa A. Social amoebae establish a protective interface with their bacterial associates by lectin agglutination. Sci Adv 2019; 5:eaav4367. [PMID: 31355329 PMCID: PMC6656538 DOI: 10.1126/sciadv.aav4367] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Accepted: 06/20/2019] [Indexed: 05/13/2023]
Abstract
Both animals and amoebae use phagocytosis and DNA-based extracellular traps as anti-bacterial defense mechanisms. Whether, like animals, amoebae also use tissue-level barriers to reduce direct contact with bacteria has remained unclear. We have explored this question in the social amoeba Dictyostelium discoideum, which forms plaques on lawns of bacteria that expand as amoebae divide and bacteria are consumed. We show that CadA, a cell adhesion protein that functions in D. discoideum development, is also a bacterial agglutinin that forms a protective interface at the plaque edge that limits exposure of vegetative amoebae to bacteria. This interface is important for amoebal survival when bacteria-to-amoebae ratios are high, optimizing amoebal feeding behavior, and protecting amoebae from oxidative stress. Lectins also control bacterial access to the gut epithelium of mammals to limit inflammatory processes; thus, this strategy of antibacterial defense is shared across a broad spectrum of eukaryotic taxa.
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Affiliation(s)
- Timothy Farinholt
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Christopher Dinh
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Adam Kuspa
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Corresponding author.
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3
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Wongpanya R, Sengprasert P, Amparyup P, Tassanakajon A. A novel C-type lectin in the black tiger shrimp Penaeus monodon functions as a pattern recognition receptor by binding and causing bacterial agglutination. Fish Shellfish Immunol 2017; 60:103-113. [PMID: 27876622 DOI: 10.1016/j.fsi.2016.11.042] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 11/15/2016] [Accepted: 11/17/2016] [Indexed: 06/06/2023]
Abstract
C-type lectins are pattern recognition proteins that play important roles in innate immunity in invertebrates by mediating the recognition of pathogens. In this study, a novel C-type lectin gene, PmCLec, was cloned and characterized from the black tiger shrimp Penaeus monodon. The open reading frame of PmCLec is 657 bp in length. It encodes a predicted protein of 218 amino acids with a calculated molecular mass and an isoelectric point of 24086 Da and 4.67, respectively. Sequence analysis of PmCLec showed similarity to members of the C-type lectin gene superfamily. The deduced protein contains a single carbohydrate recognition domain (CRD) and four conserved cysteine residues (Cys58, Cys126, Cys141, Cys149) that are involved in the formation of disulfide bridges. PmCLec transcripts are expressed in various tiger shrimp tissues, with the highest expression in the lymphoid organ. RNAi-mediated silencing of PmCLec resulted in higher cumulative mortality of knockdown shrimp after Vibrio harveyi infection compared to the control groups. Recombinant PmCLec was successfully expressed in the E. coli system. In the presence of Ca2+, purified rPmCLec protein binds and agglutinates Gram-positive bacteria (Staphylococcus aureus, S. hemolyticus), but only slightly binds and agglutinates E. coli and could not bind to the Gram-negative bacteria Bacillus megaterium and Vibrio harveyi. These results suggest that PmCLec functions as a pattern recognition receptor that is implicated in shrimp innate immunity.
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MESH Headings
- Agglutination/genetics
- Agglutination/immunology
- Amino Acid Sequence
- Animals
- Anti-Bacterial Agents/pharmacology
- Arthropod Proteins/chemistry
- Arthropod Proteins/genetics
- Arthropod Proteins/metabolism
- Base Sequence
- Cloning, Molecular
- DNA, Complementary/genetics
- DNA, Complementary/metabolism
- Escherichia coli/genetics
- Gram-Negative Bacteria/drug effects
- Gram-Positive Bacteria/drug effects
- Immunity, Innate
- Lectins, C-Type/chemistry
- Lectins, C-Type/genetics
- Lectins, C-Type/metabolism
- Penaeidae/genetics
- Penaeidae/immunology
- Penaeidae/microbiology
- Phylogeny
- Pichia/drug effects
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Pattern Recognition/chemistry
- Receptors, Pattern Recognition/genetics
- Receptors, Pattern Recognition/metabolism
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Sequence Homology, Amino Acid
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Affiliation(s)
- Ratree Wongpanya
- Department of Biochemistry, Faculty of Science, Kasetsart University, 50 Ngamwongwan Road, Bangkok 10900, Thailand.
| | - Panjana Sengprasert
- Department of Biochemistry, Faculty of Science, Kasetsart University, 50 Ngamwongwan Road, Bangkok 10900, Thailand
| | - Piti Amparyup
- Aquatic Molecular Genetics and Biotechnology Laboratory, Agricultural Biotechnology Research Unit, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Pathum Thani 12120, Thailand
| | - Anchalee Tassanakajon
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Bangkok 10330, Thailand
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Hiramatsu Y, Saito M, Otsuka N, Suzuki E, Watanabe M, Shibayama K, Kamachi K. BipA Is Associated with Preventing Autoagglutination and Promoting Biofilm Formation in Bordetella holmesii. PLoS One 2016; 11:e0159999. [PMID: 27448237 PMCID: PMC4957798 DOI: 10.1371/journal.pone.0159999] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 07/12/2016] [Indexed: 11/18/2022] Open
Abstract
Bordetella holmesii causes both invasive and respiratory diseases in humans. Although the number of cases of pertussis-like respiratory illnesses due to B. holmesii infection has increased in the last decade worldwide, little is known about the virulence factors of the organism. Here, we analyzed a B. holmesii isolate that forms large aggregates and precipitates in suspension, and subsequently demonstrated that the autoagglutinating isolate is deficient in Bordetella intermediate protein A (BipA) and that this deletion is caused by a frame-shift mutation in the bipA gene. A BipA-deficient mutant generated by homologous recombination also exhibited the autoagglutination phenotype. Moreover, the BipA mutant adhered poorly to an abiotic surface and failed to form biofilms, as did two other B. holmesii autoagglutinating strains, ATCC 51541 and ATCC 700053, which exhibit transcriptional down-regulation of bipA gene expression, indicating that autoagglutination indirectly inhibits biofilm formation. In a mouse intranasal infection model, the BipA mutant showed significantly lower levels of initial lung colonization than did the parental strain (P < 0.01), suggesting that BipA might be a critical virulence factor in B. holmesii respiratory infection. Together, our findings suggest that BipA production plays an essential role in preventing autoagglutination and indirectly promoting biofilm formation by B. holmesii.
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Affiliation(s)
- Yukihiro Hiramatsu
- Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan
- * E-mail: (YH); (KK)
| | - Momoko Saito
- Graduate School of Infection Control Sciences, Kitasato University, Tokyo, Japan
| | - Nao Otsuka
- Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Eri Suzuki
- Graduate School of Infection Control Sciences, Kitasato University, Tokyo, Japan
| | - Mineo Watanabe
- Graduate School of Infection Control Sciences, Kitasato University, Tokyo, Japan
| | - Keigo Shibayama
- Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kazunari Kamachi
- Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan
- * E-mail: (YH); (KK)
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5
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Zhang J, Qiu R, Hu YH. HdhCTL1 is a novel C-type lectin of abalone Haliotis discus hannai that agglutinates Gram-negative bacterial pathogens. Fish Shellfish Immunol 2014; 41:466-472. [PMID: 25301718 DOI: 10.1016/j.fsi.2014.09.032] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 09/16/2014] [Accepted: 09/29/2014] [Indexed: 06/04/2023]
Abstract
C-type lectins (CTLs) are Ca(2+)-dependent carbohydrate recognition proteins, which play important roles in the innate immunity of both vertebrates and invertebrates. In this study, we identified and characterized a C-type lectin (named HdhCTL1) from Pacific abalone, Haliotis discus hannai. HdhCTL1 is composed of 176 amino acid residues and shares low (23.9%) identity with the known CTL of abalone. HdhCTL1 possesses a putative signal peptide and a carbohydrate-recognition domain (CRD) typical of CTLs. The CRD of HdhCTL1 contains four disulfide bond-forming cysteine residues that are highly conserved in CTLs. HdhCTL1 mRNA was detected in a wide range of tissues and expressed abundantly in the digestive gland. Experimental infection with the bacterial pathogen Vibrio anguillarum significantly upregulated HdhCTL1 expression in a time-dependent manner. Recombinant HdhCTL1 (rHdhCTL1) purified from Escherichia coli was able to agglutinate Gram-negative bacterial pathogens. The agglutinating ability of rHdhCTL1 was abolished in the presence of mannose. These results suggest that HdhCTL1 is a novel CTL which is likely to be involved in host defense against bacterial infection.
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Affiliation(s)
- Jian Zhang
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Reng Qiu
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; China-UK-NYNU-RRes Joint Laboratory of Insect Biology, Nanyang Normal University, Nanyang, 473061 Henan, China
| | - Yong-hua Hu
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
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6
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Walker JN, Crosby HA, Spaulding AR, Salgado-Pabón W, Malone CL, Rosenthal CB, Schlievert PM, Boyd JM, Horswill AR. The Staphylococcus aureus ArlRS two-component system is a novel regulator of agglutination and pathogenesis. PLoS Pathog 2013; 9:e1003819. [PMID: 24367264 PMCID: PMC3868527 DOI: 10.1371/journal.ppat.1003819] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 10/21/2013] [Indexed: 01/31/2023] Open
Abstract
Staphylococcus aureus is a prominent bacterial pathogen that is known to agglutinate in the presence of human plasma to form stable clumps. There is increasing evidence that agglutination aids S. aureus pathogenesis, but the mechanisms of this process remain to be fully elucidated. To better define this process, we developed both tube based and flow cytometry methods to monitor clumping in the presence of extracellular matrix proteins. We discovered that the ArlRS two-component system regulates the agglutination mechanism during exposure to human plasma or fibrinogen. Using divergent S. aureus strains, we demonstrated that arlRS mutants are unable to agglutinate, and this phenotype can be complemented. We found that the ebh gene, encoding the Giant Staphylococcal Surface Protein (GSSP), was up-regulated in an arlRS mutant. By introducing an ebh complete deletion into an arlRS mutant, agglutination was restored. To assess whether GSSP is the primary effector, a constitutive promoter was inserted upstream of the ebh gene on the chromosome in a wildtype strain, which prevented clump formation and demonstrated that GSSP has a negative impact on the agglutination mechanism. Due to the parallels of agglutination with infective endocarditis development, we assessed the phenotype of an arlRS mutant in a rabbit combined model of sepsis and endocarditis. In this model the arlRS mutant displayed a large defect in vegetation formation and pathogenesis, and this phenotype was partially restored by removing GSSP. Altogether, we have discovered that the ArlRS system controls a novel mechanism through which S. aureus regulates agglutination and pathogenesis. Staphylococcus aureus is a bacterial pathogen that is responsible for causing significant disease in humans. The development of antibiotic resistant strains has made these infections more difficult to treat, and an improved understanding of how this pathogen causes infections will facilitate the development of new tools for treatment. It has long been recognized that S. aureus can bind human matrix proteins to form stable clumps in a process called agglutination, but the importance of agglutination during infection is only just becoming understood. In this work, we developed several techniques to investigate the S. aureus agglutination mechanism. We discovered that the ArlRS two-component regulatory system controls agglutination by regulating the expression of the ebh gene, which encodes the Giant Staphylococcal Surface Protein (GSSP). When ArlRS is non-functional, S. aureus agglutination is prevented through the action of GSSP. These phenotypes were confirmed in a rabbit model of sepsis and infective endocarditis, demonstrating that ArlRS is an important regulator of virulence. Taken together, the identification of ArlRS as a regulator of S. aureus agglutination and pathogenesis may lead to innovative directions for therapeutic development.
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Affiliation(s)
- Jennifer N Walker
- Department of Microbiology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Heidi A Crosby
- Department of Microbiology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Adam R Spaulding
- Department of Microbiology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Wilmara Salgado-Pabón
- Department of Microbiology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Cheryl L Malone
- Department of Microbiology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Carolyn B Rosenthal
- Department of Microbiology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Patrick M Schlievert
- Department of Microbiology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Jeffrey M Boyd
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Alexander R Horswill
- Department of Microbiology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
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7
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Sato Y, Okamoto K, Kagami A, Yamamoto Y, Ohta K, Igarashi T, Kizaki H. Application ofIn VitroMutagenesis to Identify the Gene Responsible for Cold Agglutination Phenotype ofStreptococcus mutans. Microbiol Immunol 2013; 48:449-56. [PMID: 15215618 DOI: 10.1111/j.1348-0421.2004.tb03535.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
A previously unidentified protein with an apparent molecular mass of 120 kDa was detected in some Streptococcus mutans strains including the natural isolate strain Z1. This protein was likely involved in the cold-agglutination of the strain, since a correlation between this phenotype and expression of the 120 kDa protein was found. We have applied random mutagenesis by in vitro transposition with the Himar1 minitransposon and isolated three cold-agglutination-negative mutants of this strain from approximately 2,000 mutants screened. A 2.5 kb chromosomal fragment flanking the minitransposon in one of the three mutants was amplified by PCR-based chromosome walking and the minitransposon insertion in the other two mutants occurred also within the same region. Nucleotide sequencing of the region revealed a 1617 nt open reading frame specifying a putative protein of 538 amino acid residues with a calculated molecular weight of 57,192. The deduced eight amino acid sequence following a putative signal sequence completely coincided with the N-terminal octapeptide sequence of the 120 kDa protein determined by the Edman degradation. Therefore, the 1617 nt gene unexpectedly encoded the 120 kDa protein from S. mutans. Interestingly, this gene encoded a collagen adhesin homologue. In vitro mutagenesis using the Himar1 minitransposon was successfully applied to S. mutans.
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Affiliation(s)
- Yutaka Sato
- Department of Biochemistry, Tokyo Dental College, Chiba, Japan.
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8
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Utani A. [Laminin alpha3 chain-derived peptide promotes keratinocyte migration and wound closure: clustering of syndecan-4 and integrin beta1]. Seikagaku 2010; 82:327-331. [PMID: 20496754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Affiliation(s)
- Atsushi Utani
- Department of Dermatology, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto, Japan
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9
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Yamazaki T, Narita M, Sasaki N, Kenri T, Arakawa Y, Sasaki T. Comparison of PCR for Sputum Samples Obtained by Induced Cough and Serological Tests for Diagnosis of
Mycoplasma pneumoniae
Infection in Children. Clin Vaccine Immunol 2006; 13:708-10. [PMID: 16760332 PMCID: PMC1489559 DOI: 10.1128/cvi.00413-05] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
ABSTRACT
Passive agglutination (PA) and immunoglobulin M (IgM), IgA, and IgG enzyme-linked immunosorbent assays (ELISAs) for the diagnosis of
Mycoplasma pneumoniae
were compared with PCR testing of sputum samples obtained from children with lower respiratory tract infections. The sensitivity and specificity of PA were 80.3% and 92.3% at a titer of 1:80. ELISA was found to be less sensitive than PA.
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Affiliation(s)
- Tsutomu Yamazaki
- Department of Pediatrics, Saitama Medical School, Morohongo 38, Moroyama, Iruma, 350-0495 Japan.
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10
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Podladchikova ON, Rykova VA. [Identification of the autoagglutination factor of Hms- cells of the plague agent]. Mol Gen Mikrobiol Virusol 2006:25-9. [PMID: 16755999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A search for cellular components responsible for autoagglutination (AA) in broth and salt solutions of Hms- cells of the plague agent Yersinia pestis was performed. The AA- mutants were obtained using vaccine strain Y. pestis EV76 derivative containing one species-specific plasmid pYP. The mutants were shown to differ from the parent strain by the decreased surface hydrophobicity, insensitivity to plague diagnostic L-413c bacteriophage and negative haemagglutination reaction with antibodies to F1 capsular substance of the plague agent. The mutants did not differ from the parent strain by electrophoretic mobility and immunochemical activity of LPS but were characterized by the absence of a 17 kDa protein on the cell surface. The AA+ cells that lost this protein after weak alkali extraction were less hydrophobic and failed to express AA in 0.5 M ammonium sulfate. After the extraction, the cells lost the ability to neutralize L-413c and to react with the anti-F1 antibodies, while both activities as well as 17 kDa protein were detected in the extracts. Thus, the 17 kDa protein is suggested to be a hydrophobic surface antigen which acts as a receptor of the L-413c bacteriophage and represents an AA factor of Hms- cells of Y. pestis.
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11
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Buell CR, Anderson AJ. Expression of the aggA locus of Pseudomonas putida in vitro and in planta as detected by the reporter gene, xylE. Mol Plant Microbe Interact 1993; 6:331-340. [PMID: 8324250 DOI: 10.1094/mpmi-6-331] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In vitro agglutinability by Pseudomonas putida, isolate Corvallis, with a plant root surface agglutinin is correlated with rapid adhesion of cells of the fluorescent pseudomonad to bean (Phaseolus vulgaris) root surfaces. Agglutinability in P. putida cells is regulated by nutrient status as well as growth phase. Cells grown in three different nutrient complex media are agglutinable at early and mid-late logarithmic phase but become nonagglutinable at stationary phase. Cells grown in a minimal medium are weakly agglutinable, but the addition of lysine, aspartic acid, or histidine increases agglutinability. Cells in the same minimal medium supplemented with bean root surface components grow in a highly agglutinated state. Previous data indicate both agglutination and rapid adhesion to roots by P. putida Corvallis involves the aggA locus, which contains two putative open reading frames (ORF), ORF-AGG1 and ORFAGG2, on complementary strands. Sequence and deletion analyses suggest ORFAGG1 is the most probable ORF responsible for agglutination and adhesion. Chimeric fusion of an Escherichia coli lac promoter with ORFAGG1, but not with ORFAGG2, complemented agglutinability of an aggA::Tn5 P. putida Agg mutant, providing further evidence that ORFAGG1, not ORFAGG2, is responsible for agglutination. Heterologous expression of ORFAGG1 yields a 50-kDa precursor and a 48-kDa mature periplasmic protein. Fusions of ORFAGG1 and ORFAGG2 to the reporter gene, xylE, and detection of the reporter enzyme, catechol-2,3-oxygenase reveal an active promoter in the 5' noncoding region of ORFAGG1. The ORFAGG1 promoter is active during growth of the cells in liquid culture and is regulated by growth medium. Greatest activity of the catechol-2,3-oxygenase is observed in stationary phase when the cells are nonagglutinable. Expression of the ORFAGG1 promoter is detected in P. putida cells extracted from the root surface of bean at 48 and 72 hr after inoculation.
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Affiliation(s)
- C R Buell
- Department of Biology, Utah State University, Logan 84322-5305
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