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Metagenomic analysis of diarrheal stools in Kolkata, India, indicates the possibility of subclinical infection of Vibrio cholerae O1. Sci Rep 2022; 12:19473. [PMID: 36376441 PMCID: PMC9663449 DOI: 10.1038/s41598-022-24167-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 11/10/2022] [Indexed: 11/16/2022] Open
Abstract
We examined the stools of 23 patients in Kolkata, who were diagnosed as cholera patients because Vibrio cholerae O1 was detected from their stools by culturing methods, and further explored by metagenomic sequencing analysis. Subsequently, the presence of the gene encoding A subunit of cholera toxin (ctxA) and the cholera toxin (CT) level in these stool samples were examined. ctxA was examined by both metagenomic sequencing analysis and polymerase chain reaction. In these examinations, two samples did not show positive in any of these tests. The metagenomic analysis showed that the genes for Streptococcus pneumoniae and Salmonella enterica were present in the stools of these two patients, respectively. Therefore, these two patients were not considered to have diarrhea due to V. cholerae infection. From these results, we predicted that some Kolkata residents harbor a small number of V. cholerae in their intestines as a form of subclinical infection with V. cholerae. Next, we analyzed the stool samples of 22 diarrhea patients from which V. cholerae was not isolated. The results showed that 3 of the patients seemed to have subclinical infection of V. cholerae based on the amount of the genes. These results indicated that subclinical infections with V. cholerae O1 occur in Kolkata.
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Wickramanayake MVKS, Dahanayake PS, Hossain S, Heo GJ. Antimicrobial resistance of pathogenic Aeromonas spp. isolated from marketed Pacific abalone (Haliotis discus hannai) in Korea. J Appl Microbiol 2019; 128:606-617. [PMID: 31606917 DOI: 10.1111/jam.14485] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 09/30/2019] [Accepted: 10/08/2019] [Indexed: 11/28/2022]
Abstract
AIMS The object of this study was to identify potential health concerns of the Aeromons spp. isolated from marketed Pacific abalone (Haliotis discus hannai) with respect to their virulence and antimicrobial resistance patterns. METHODS AND RESULTS We identified 29 strains of aeromonads consisting of five species; Aeromonas hydrophila (n = 9), Aeromonas enteropelogenes (n = 14), Aeromonas veronii (n = 3), Aeromonas salmonicida (n = 2) and Aeromonas sobria (n = 1), by employing series of biochemical tests and gene sequencing. In the phenotypic virulence assays, all isolates showed gelatinase and caseinase activities, while lipase formation (69%), phospholipase production (90%), DNase formation (82%), slime production (49%) and haemolysis activity (α = 18% and β = 82%) were also detected among isolates. Prevalence of virulence genes; aerA (100%), fla (66%), ahyB (73%), act (52%), alt (42%), ast (35%), ser (52%), gcat (69%), ascV (43%), hlyA (83%), lip (52%) and exu (59%) were detected by PCR assays. In disc diffusion test, 100% resistance was detected against ampicillin while cephalothin, rifampicin, oxytetracycline, colistine sulphate, nalidixic acid and piperaciliin were resisted by 86, 73, 42, 35, 28, 20 and 20% of the isolates respectively. Thirteen (45%) of the isolates showed multiple antimicrobial resistance (MAR) indices ≥ 0·2. CONCLUSIONS Our findings suggest that the potential health risk posed by the abalone-borne Aeromonas spp. should not be underestimated. SIGNIFICANCE AND IMPACT OF THE STUDY This is the first time to evaluate possible public health risks upon consumption of abalone harbored Aeromonas spp. and also to isolate potential pathogenic and multidrug-resistant Aeromonas spp. from Pacific abalone in Korea.
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Affiliation(s)
- M V K S Wickramanayake
- Laboratory of Aquatic Animal Medicine, Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju, 28644, Republic of Korea
| | - P S Dahanayake
- Laboratory of Aquatic Animal Medicine, Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju, 28644, Republic of Korea
| | - Sabrina Hossain
- Laboratory of Aquatic Animal Medicine, Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju, 28644, Republic of Korea
| | - Gang-Joon Heo
- Laboratory of Aquatic Animal Medicine, Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju, 28644, Republic of Korea
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Wang D, Sun F, Li Z, Hu Y, Xu R. Acute septic arthritis of shoulder joint caused by Aeromonas veronii biotype sobria. DER ORTHOPADE 2018; 47:1027-1031. [PMID: 29872872 DOI: 10.1007/s00132-018-3585-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
We present the case of a 91-year-old woman who presented with a 2‑day history of progressive pain and immobility of the right shoulder joint after fever of unknown etiology. Aeromonas sobria was isolated from a culture of purulent synovial fluid. The clinical condition gradually improved with the application of appropriate antibiotics and no surgical intervention was necessary. This report indicates that acute septic arthritis may result from Aeromonas veronii biotype sobria infections in healthy people. This case is contrary to the previous reports due to the absence of obvious risk factors.
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Affiliation(s)
- Dexin Wang
- Department of Orthopaedics, Mingzhou Hospital of Zhejiang University, 168 Taian West Road, Ningbo, Zhejiang Province, China
| | - Fanggui Sun
- Department of Orthopaedics, Mingzhou Hospital of Zhejiang University, 168 Taian West Road, Ningbo, Zhejiang Province, China
| | - Zheng Li
- Department of Orthopaedics, Mingzhou Hospital of Zhejiang University, 168 Taian West Road, Ningbo, Zhejiang Province, China
| | - Yutong Hu
- Department of Orthopaedics, Mingzhou Hospital of Zhejiang University, 168 Taian West Road, Ningbo, Zhejiang Province, China
| | - Rongming Xu
- Department of Orthopaedics, Mingzhou Hospital of Zhejiang University, 168 Taian West Road, Ningbo, Zhejiang Province, China.
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Imamura T, Murakami Y, Nitta H. Aeromonas sobria serine protease (ASP): a subtilisin family endopeptidase with multiple virulence activities. Biol Chem 2017; 398:1055-1068. [PMID: 28432839 DOI: 10.1515/hsz-2016-0344] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 04/07/2017] [Indexed: 11/15/2022]
Abstract
Aeromonas sobria serine protease (ASP) is secreted from Aeromonas sobria, a pathogen causing gastroenteritis and sepsis. ASP resembles Saccharomyces cerevisiae Kex2, a member of the subtilisin family, and preferentially cleaves peptide bonds at the C-terminal side of paired basic amino acid residues; also accepting unpaired arginine at the P1 site. Unlike Kex2, however, ASP lacks an intramolecular chaperone N-terminal propeptide, instead utilizes the external chaperone ORF2 for proper folding, therefore, ASP and its homologues constitute a new subfamily in the subtilisin family. Through activation of the kallikrein/kinin system, ASP induces vascular leakage, and presumably causes edema and septic shock. ASP accelerates plasma clotting by α-thrombin generation from prothrombin, whereas it impairs plasma clottability by fibrinogen degradation, together bringing about blood coagulation disorder that occurs in disseminated intravascular coagulation, a major complication of sepsis. From complement C5 ASP liberates C5a that induces neutrophil recruitment and superoxide release, and mast cell degranulation, which are associated with pus formation, tissue injury and diarrhea, respectively. Nicked two-chain ASP also secreted from A. sobria is more resistant to inactivation by α2-macroglobulin than single-chain ASP, thereby raising virulence activities. Thus, ASP is a potent virulence factor and may participate in the pathogenesis of A. sobria infection.
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Takahashi E, Fujinami C, Kuroda T, Takeuchi Y, Miyoshi SI, Arimoto S, Negishi T, Okamoto K. Indolo[3,2-b]quinoline Derivatives Suppressed the Hemolytic Activity of Beta-Pore Forming Toxins, Aerolysin-Like Hemolysin Produced by Aeromonas sobria and Alpha-Hemolysin Produced by Staphylococcus aureus. Biol Pharm Bull 2016; 39:114-20. [PMID: 26725434 DOI: 10.1248/bpb.b15-00708] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In an attempt to discover inhibitory compounds against pore-forming toxins, some of the major toxins produced by bacteria, we herein examined the effects of four kinds of indolo[3,2-b]quinoline derivatives on hemolysis induced by the aerolysin-like hemolysin (ALH) of Aeromonas sobria and also by the alpha-hemolysin of Staphylococcus aureus. The results showed that hemolysis induced by ALH was significantly reduced by every derivative, while that induced by alpha-hemolysis was significantly reduced by three out of the four derivatives. However, the degrees of reduction induced by these derivatives were not uniform. Each derivative exhibited its own activity to inhibit the respective hemolysin. Compounds 1 and 2, which possessed the amino group bonding the naphthalene moiety at the C-11 position of indolo[3,2-b]quinoline, had strong inhibitory effects on the activity of ALH. Compound 4 which consisted of benzofuran and quinoline had strong inhibitory effects on the activity of alpha-hemolysin. These results indicated that the amino group bonding the naphthalene moiety of compounds 1 and 2 assisted in their ability to inhibit ALH activity, while the oxygen atom at the 10 position of compound 4 strengthened its interaction with alpha-hemolysin. These compounds also suppressed the hemolytic activity of the supernatant of A. sobria or A. hydrophila, suggesting that these compounds were effective at the site of infection of these bacteria.
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Affiliation(s)
- Eizo Takahashi
- Faculty of Pharmaceutical Sciences, Nihon Pharmaceutical University
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Laishram S, Pennathur G. Purification and Characterization of a Membrane-Unbound Highly Thermostable Metalloprotease from Aeromonas Caviae. ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING 2015. [DOI: 10.1007/s13369-015-1849-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Takahashi E, Ozaki H, Fujii Y, Kobayashi H, Yamanaka H, Arimoto S, Negishi T, Okamoto K. Properties of hemolysin and protease produced by Aeromonas trota. PLoS One 2014; 9:e91149. [PMID: 24633045 PMCID: PMC3954626 DOI: 10.1371/journal.pone.0091149] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 02/07/2014] [Indexed: 01/01/2023] Open
Abstract
We examined the properties of exotoxins produced by Aeromonas trota (A. enteropelogenes), one of the diarrheagenic species of Aeromonadaceae. Nine of 19 A. trota isolates that grew on solid media containing erythrocytes showed hemolytic activity. However, the hemolytic activities of the culture supernatants of these hemolytic strains of A. trota were markedly lower than those of A. sobria when cultured in liquid medium, and the amount of hemolysin detected by immunoblotting using antiserum against the hemolysin produced by A. sobria was also low. A mouse intestine loop assay using living bacterial cells showed that A. trota 701 caused the significant accumulation of fluid, and antiserum against the hemolysin produced suppressed the enterotoxic action of A. trota 701. These results indicated that A. trota 701 was diarrheagenic and the hemolysin produced was the causative agent of the enterotoxic activity of A. trota. The hemolysin in A. sobria was previously shown to be secreted in a preform (inactive form) and be activated when the carboxy-terminal domain was cleaved off by proteases in the culture supernatant. Since mature hemolysin was detected in the culture supernatants of A. trota, we analyzed the extracellular protease produced by A. trota. Fifteen of 19 A. trota isolates that grew on solid media containing skim milk showed proteolytic activity. We subsequently found that most A. trota isolates possessed the serine protease gene, but not the metalloprotease gene. Therefore, we determined the nucleotide sequence of the serine protease gene and its chaperone A. trota gene. The results obtained revealed that the deduced amino acid sequences of serine protease and the chaperone were homologous to those of A. sobria with identities of 83.0% and 75.8%, respectively.
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Affiliation(s)
- Eizo Takahashi
- Laboratory of Protein Function, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Tsushima, Okayama, Japan
- * E-mail:
| | - Haruka Ozaki
- Laboratory of Protein Function, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Tsushima, Okayama, Japan
| | - Yoshio Fujii
- Course of Clinical Pharmacy, Yokohama College of Pharmacy, Yokohama, Kanagawa, Japan
- Institute of Pharmacognosy, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro, Tokushima, Japan
| | - Hidetomo Kobayashi
- Laboratory of Molecular Microbiological Science, Faculty of Pharmaceutical Sciences, Hiroshima International University, Kure, Hiroshima, Japan
| | - Hiroyasu Yamanaka
- Laboratory of Molecular Microbiological Science, Faculty of Pharmaceutical Sciences, Hiroshima International University, Kure, Hiroshima, Japan
| | - Sakae Arimoto
- Laboratory of Protein Function, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Tsushima, Okayama, Japan
| | - Tomoe Negishi
- Laboratory of Protein Function, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Tsushima, Okayama, Japan
| | - Keinosuke Okamoto
- Laboratory of Protein Function, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Tsushima, Okayama, Japan
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Takahashi E, Ito H, Kobayashi H, Yamanaka H, Takeda Y, Balakrish Nair G, Arimoto S, Negishi T, Okamoto K. Production and properties of lipase of Aeromonas sobria. Microbiol Immunol 2012; 56:295-307. [PMID: 22376235 DOI: 10.1111/j.1348-0421.2012.00445.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Aeromonas have been isolated from a wide variety of aquatic environments. However the number of Aeromonas in sea water is extremely small compared to that in fresh water. In in vitro culture, Aeromonas can grow in mediums containing NaCl at a concentration of 3.0%, this concentration corresponding to that of sea water. It is unclear why the number of Aeromonas is low in sea water. Exoproteins of bacteria are thought to be important for bacterial growth and survival in the environment. Previously, the present authors have shown that mediums containing 3.0% NaCl suppress production of two proteases, serine protease and metalloprotease. In this experiment, other exoproteins whose production is influenced by the amount of NaCl in the medium were analyzed. A protein whose production is repressed in medium containing 3.0% NaCl was found and purified. Biological assay of the purified protein showed that it degrades tributyrin and hydrolyzes para-nitrophenyl-fatty acylesters. These results show that the protein is a lipase. Subsequently, the nucleotide sequence of the gene encoding the lipase was determined and the amount of mRNA of the lipase gene in the cells measured. It was found that transcription of the gene is not inhibited by NaCl in the medium. This result indicates that the lipase might be synthesized, but the folding process to become an active structure does not progress smoothly in a medium containing 3.0% NaCl.
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Affiliation(s)
- Eizo Takahashi
- Laboratory of Protein Function, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Kitaku, Okayama, Japan.
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Divakar K, Deepa Arul Priya J, Gautam P. Purification and characterization of thermostable organic solvent-stable protease from Aeromonas veronii PG01. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.molcatb.2010.06.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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10
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Tsai YH, Huang KC, Huang TJ, Hsu RWW. Case reports: fatal necrotizing fasciitis caused by Aeromonas sobria in two diabetic patients. Clin Orthop Relat Res 2009; 467:846-9. [PMID: 18800212 PMCID: PMC2635452 DOI: 10.1007/s11999-008-0504-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2008] [Accepted: 08/26/2008] [Indexed: 01/31/2023]
Abstract
We report two rare cases of Aeromonas sobria necrotizing fasciitis with sepsis in patients with diabetes. In both cases, immediate fasciotomy was performed and appropriate empiric antimicrobial therapy and intensive care were administered. However, the two patients died on Day 2 and Day 11, respectively, after admission as a result of multiple organ failure. When patients present with a rapid onset of skin necrosis and progressive sepsis, an Aeromonas sobria infection or Vibrio infection should be considered in the differential diagnosis.
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Affiliation(s)
- Yao-Hung Tsai
- Department of Orthopaedic Surgery, Chang Gung Memorial Hospital, Chia-Yi, Chang Gung University College of Medicine, No 6, West Sec, Chia-Pu Road, Putz City, Chia-Yi, 613 Taiwan, ROC
| | - Kuo-Chin Huang
- Department of Orthopaedic Surgery, Chang Gung Memorial Hospital, Chia-Yi, Chang Gung University College of Medicine, No 6, West Sec, Chia-Pu Road, Putz City, Chia-Yi, 613 Taiwan, ROC
| | - Tsung-Jen Huang
- Department of Orthopaedic Surgery, Chang Gung Memorial Hospital, Chia-Yi, Chang Gung University College of Medicine, No 6, West Sec, Chia-Pu Road, Putz City, Chia-Yi, 613 Taiwan, ROC
| | - Robert Wen-Wei Hsu
- Department of Orthopaedic Surgery, Chang Gung Memorial Hospital, Chia-Yi, Chang Gung University College of Medicine, No 6, West Sec, Chia-Pu Road, Putz City, Chia-Yi, 613 Taiwan, ROC
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Imamura T, Nitta H, Wada Y, Kobayashi H, Okamoto K. Impaired plasma clottability induction through fibrinogen degradation by ASP, a serine protease released from Aeromonas sobria. FEMS Microbiol Lett 2008; 284:35-42. [PMID: 18462393 PMCID: PMC2613230 DOI: 10.1111/j.1574-6968.2008.01184.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Aeromonas sobria infection often advances to sepsis, in which interaction of bacterial components with plasma proteins possibly causes various disorders. This bacterium releases a serine protease (ASP), a putative virulence factor, and binds to fibrinogen. To study the ASP effect on fibrinogen, we incubated fibrinogen or plasma with ASP and investigated their clotting elicited by thrombin, which converts fibrinogen to a fibrin clot. Enzymatically active ASP retarded plasma clotting in a dose-dependent manner starting at an ASP concentration of 10 nM. ASP also retarded fibrinogen clotting at 3 nM and above, which appeared to correspond to ASP cleavage of fibrinogen at the A alpha-chain. Consistent with containing serine protease activity for an ASP-specific substrate, the culture supernatant of an ASP gene-introduced strain retarded plasma and fibrinogen clotting more than that of the wild-type strain. The culture supernatant of an ASP gene-disrupted strain that releases negligible serine protease activity for the ASP-specific substrate did not affect plasma clotting. These results indicate that ASP is the main fibrinogenolytic protease released from A. sobria. Impaired plasma clottability induction through fibrinogen degradation is a new virulence activity of ASP and may contribute to hemorrhagic tendencies in sepsis caused by infection with this bacterium.
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Affiliation(s)
- Takahisa Imamura
- Department of Molecular Pathology, Faculty of Medical and Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan.
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Khan R, Takahashi E, Ramamurthy T, Takeda Y, Okamoto K. Salt in surroundings influences the production of serine protease into milieu by Aeromonas sobria. Microbiol Immunol 2008; 51:963-76. [PMID: 17951986 DOI: 10.1111/j.1348-0421.2007.tb03993.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Previously we have shown that the open reading frame 2 protein (ORF2 protein), which is encoded at the 3 ' end of serine protease of Aeromonas sobria (ASP), functions as a chaperone protein in periplasm in the production of ASP. Both proteins, ASP and ORF2 protein, associate in periplasm and ORF2 protein helps ASP to take an active form. ASP which is dissociated from ORF2 protein emerges in milieu . In this study, we examined the effect of sodium chloride (NaCl) in medium on ASP production by A. sobria. The ASP activity of culture supernatant was extremely decreased when A. sobria was cultured in medium containing 3.0% NaCl (concentration almost equivalent to sea water salinity). Our analysis showed that the transcription of asp by A. sobria is not inhibited by NaCl in medium and that A. sobria synthesizes and releases ASP in milieu even under the condition of 3.0% NaCl. However, these ASPs in milieu formed complex as with ORF2 proteins. This indicates that the maturation pathway of ASP is disturbed in A. sobria cultured in medium containing 3.0% NaCl. It is likely that ASP does not associate with ORF2 protein in the correct form in periplasam when A. sobria is cultured in medium containing 3.0% NaCl, though both proteins, ASP and ORF2 protein, make complexes and emerge outside of the cell. This idea suggests that the chaperone system of ASP possesses the ability to sense NaCl in surroundings and regulates the production of active ASP.
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Affiliation(s)
- Rasel Khan
- Laboratory of Protein Function, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8530, Japan
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Imamura T, Kobayashi H, Khan R, Nitta H, Okamoto K. Induction of vascular leakage and blood pressure lowering through kinin release by a serine proteinase from Aeromonas sobria. THE JOURNAL OF IMMUNOLOGY 2007; 177:8723-9. [PMID: 17142774 DOI: 10.4049/jimmunol.177.12.8723] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Aeromonas sobria causes septic shock, a condition associated with high mortality. To study the mechanism of septic shock by A. sobria infection, we examined the vascular leakage (VL) activity of A. sobria serine proteinase (ASP), a serine proteinase secreted by this pathogen. Proteolytically active ASP induced VL mainly in a bradykinin (BK) B(2) receptor-, and partially in a histamine-H(1) receptor-dependent manner in guinea pig skin. The ASP VL activity peaked at 10 min to 1.8-fold of the initial activity with an increased BK B(2) receptor dependency, and attenuated almost completely within 30 min. ASP produced VL activity from human plasma apparently through kallikrein/kinin system activation, suggesting that ASP can generate kinin in humans. Consistent with the finding that a major part of the ASP-induced VL was reduced by a potent kallikrein inhibitor, soybean trypsin inhibitor that does not affect ASP enzymatic activity, ASP activated prekallikrein but not factor XII to generate kallikrein in a dose- and incubation time-dependent manner. ASP produced more VL activity directly from human low m.w. kininogen than high m.w. kininogen when both were used at their normal plasma concentrations. Intra-arterial injection of ASP into guinea pigs lowered blood pressure specifically via the BK B(2) receptor. These data suggest that ASP induces VL through prekallikrein activation and direct kinin release from kininogens, which is a previously undescribed mechanism of A. sobria virulence and could be associated with the induction of septic shock by infection with this bacterium. ASP-specific inhibitors, and kinin receptor antagonists, might prove useful for the treatment or prevention of this fatal disease.
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Affiliation(s)
- Takahisa Imamura
- Department of Molecular Pathology, Faculty of Medical and Pharmaceutical Services, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556.
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Morinaga N, Yahiro K, Matsuura G, Watanabe M, Nomura F, Moss J, Noda M. Two distinct cytotoxic activities of subtilase cytotoxin produced by shiga-toxigenic Escherichia coli. Infect Immun 2006; 75:488-96. [PMID: 17101670 PMCID: PMC1828409 DOI: 10.1128/iai.01336-06] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Subtilase cytotoxin (SubAB) is a recently identified AB5 subunit toxin produced by Shiga-toxigenic Escherichia coli. The A subunit is thought to be a subtilase-like, serine protease, whereas the B subunit binds to the toxin receptor on the cell surface. We cloned the genes from a clinical isolate; the toxin was produced as His-tagged proteins. SubAB induced vacuolation at concentrations greater than 1 microg/ml after 8 h, in addition to the reported cytotoxicity induced at a ng/ml level after 48 h. Vacuolation was induced with the B, but not the A, subunit and was dependent on V-type ATPase. The cytotoxicity of SubAB at low concentrations was associated with the inhibition of protein synthesis; the 50% inhibitory dose was approximately 1 ng/ml. The A subunit, containing serine 272, which is thought to be a part of the catalytic triad of a subtilase-like serine protease, plus the B subunit was necessary for this activity, both in vivo and in vitro. SubAB did not cleave azocasein, bovine serum albumin, ovalbumin, or synthetic peptides. These data suggest that SubAB is a unique AB toxin: first, the B subunit alone can induce vacuolation; second, the A subunit containing serine 272 plus the B subunit inhibited protein synthesis, both in vivo and in vitro; and third, the A subunit proteolytic activity may have a strict range of substrate specificity.
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Affiliation(s)
- Naoko Morinaga
- Department of Molecular Infectiology, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba 260-8670, Japan.
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Nicholson J, Mirtschin P, Madaras F, Venning M, Kokkinn M. Digestive properties of the venom of the Australian Coastal Taipan, Oxyuranus scutellatus (Peters, 1867). Toxicon 2006; 48:422-8. [PMID: 16899265 DOI: 10.1016/j.toxicon.2006.06.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Revised: 06/07/2006] [Accepted: 06/07/2006] [Indexed: 11/21/2022]
Abstract
The digestive properties of Australian elapid snake venoms have not been studied to any great extent. To address this, the in vitro digestive properties of Oxyuranus scutellatus (Australian Coastal Taipan) venom were investigated in a simulation of the in vivo conditions using the parameters reported for the stomach of snakes and representative prey for this species. The amount of soluble protein released was measured over time using a bicinchoninic acid (BCA) assay. Dismembered mouse hindlegs were injected intramuscularly with 0.1 ml O. scutellatus venom (concentration 10 mg/ml) and maintained in a micro-anaerobic, acidic environment (pH approximately 1.2-1.7) at 25 degrees C. The bathing liquid was sampled every 24 h for 7 days, and assayed for soluble protein. Statistical analysis revealed that O. scutellatus venom increased the rate at which proteins were released when compared to a negative control suggesting the potential importance of envenomation in the digestion of whole prey.
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Affiliation(s)
- Jay Nicholson
- University of South Australia, Frome Road, Adelaide, South Australia 5000, Australia.
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Nomura T, Fujii Y, Yamanaka H, Kobayashi H, Okamoto K. The protein encoded at the 3' end of the serine protease gene of Aeromonas sobria functions as a chaperone in the production of the protease. J Bacteriol 2002; 184:7058-61. [PMID: 12446656 PMCID: PMC135477 DOI: 10.1128/jb.184.24.7058-7061.2002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
For the successful production of Aeromonas sobria serine protease (ASP), open reading frame 2 (ORF2) protein, encoded at the 3' end of the protease operon, is required. In this study, we examined the action of ORF2 protein. The results showed that the protein associated with ASP in the periplasm and helped ASP to form an active structure.
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Affiliation(s)
- Tomohiko Nomura
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro, Japan.
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