Biological characterization of a new type III secretion system effector from a clinical isolate of Aeromonas hydrophila—Part II

2007 ◽  
Vol 43 (4) ◽  
pp. 147-160 ◽  
Author(s):  
Johanna C. Sierra ◽  
Giovanni Suarez ◽  
Jian Sha ◽  
Sheri M. Foltz ◽  
Vsevolod L. Popov ◽  
...  
Keyword(s):  
Clinical Isolate ◽  
Aeromonas Hydrophila ◽  
Type Iii Secretion ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Biological Characterization ◽  
Type Iii ◽  
New Type

scholarly journals Unraveling the mechanism of action of a new type III secretion system effector AexU from Aeromonas hydrophila

2010 ◽  
Vol 49 (3) ◽  
pp. 122-134 ◽  
Author(s):  
Johanna C. Sierra ◽  
Giovanni Suarez ◽  
Jian Sha ◽  
Wallace B. Baze ◽  
Sheri M. Foltz ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Aeromonas Hydrophila ◽  
Type Iii Secretion ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Type Iii ◽  
New Type

scholarly journals The Type III Secretion System and Cytotoxic Enterotoxin Alter the Virulence of Aeromonas hydrophila

2005 ◽  
Vol 73 (10) ◽  
pp. 6446-6457 ◽  
Author(s):  
Jian Sha ◽  
Lakshmi Pillai ◽  
Amin A. Fadl ◽  
Cristi L. Galindo ◽  
Tatiana E. Erova ◽  
...  
Keyword(s):  
Aeromonas Hydrophila ◽  
Type Iii Secretion ◽  
Cultured Cells ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Effector Proteins ◽  
Host Cells ◽  
Gene Encoding ◽  
Type Iii ◽  
Isogenic Mutants

ABSTRACT Many gram-negative bacteria use a type III secretion system (TTSS) to deliver effector proteins into host cells. Here we report the characterization of a TTSS chromosomal operon from the diarrheal isolate SSU of Aeromonas hydrophila. We deleted the gene encoding Aeromonas outer membrane protein B (AopB), which is predicted to be involved in the formation of the TTSS translocon, from wild-type (WT) A. hydrophila as well as from a previously characterized cytotoxic enterotoxin gene (act)-minus strain of A. hydrophila, thus generating aopB and act/aopB isogenic mutants. The act gene encodes a type II-secreted cytotoxic enterotoxin (Act) that has hemolytic, cytotoxic, and enterotoxic activities and induces lethality in a mouse model. These isogenic mutants (aopB, act, and act/aopB) were highly attenuated in their ability to induce cytotoxicity in RAW 264.7 murine macrophages and HT-29 human colonic epithelial cells. The act/aopB mutant demonstrated the greatest reduction in cytotoxicity to cultured cells after 4 h of infection, as measured by the release of lactate dehydrogenase enzyme, and was avirulent in mice, with a 90% survival rate compared to that of animals infected with Act and AopB mutants, which caused 50 to 60% of the animals to die at a dose of three 50% lethal doses. In contrast, WT A. hydrophila killed 100% of the mice within 48 h. The effects of these mutations on cytotoxicity could be complemented with the native genes. Our studies further revealed that the production of lactones, which are involved in quorum sensing (QS), was decreased in the act (32%) and aopB (64%) mutants and was minimal (only 8%) in the act/aopB mutant, compared to that of WT A. hydrophila SSU. The effects of act and aopB gene deletions on lactone production could also be complemented with the native genes, indicating specific effects of Act and the TTSS on lactone production. Although recent studies with other bacteria have indicated TTSS regulation by QS, this is the first report describing a correlation between the TTSS and Act of A. hydrophila and the production of lactones.

scholarly journals Identification and characterization of a type III secretion-associated chaperone in the type III secretion system 1 ofVibrio parahaemolyticus

2009 ◽  
Vol 296 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Yukihiro Akeda ◽  
Kanna Okayama ◽  
Tomomi Kimura ◽  
Rikard Dryselius ◽  
Toshio Kodama ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Type Iii ◽  
System 1 ◽  
Identification And Characterization

Evaluation of biofilm production and characterization of genes encoding type III secretion system among Pseudomonas aeruginosa isolated from burn patients

Burns ◽  
2012 ◽  
Vol 38 (8) ◽  
pp. 1192-1197 ◽  
Author(s):  
Fereshteh Jabalameli ◽  
Akbar Mirsalehian ◽  
Babak Khoramian ◽  
Marzieh Aligholi ◽  
Seyed Sajjad Khoramrooz ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Type Iii Secretion ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Burn Patients ◽  
Type Iii ◽  
Biofilm Production ◽  
Genes Encoding

scholarly journals A Type III Secretion System Is Required for Aeromonas hydrophila AH-1 Pathogenesis

2004 ◽  
Vol 72 (3) ◽  
pp. 1248-1256 ◽  
Author(s):  
H. B. Yu ◽  
P. S. Srinivasa Rao ◽  
H. C. Lee ◽  
S. Vilches ◽  
S. Merino ◽  
...  
Keyword(s):  
Aeromonas Hydrophila ◽  
Type Iii Secretion ◽  
Type Iii Secretion System ◽  
Gene Clusters ◽  
Opportunistic Pathogen ◽  
Secretion System ◽  
Virulence Determinants ◽  
Degenerate Primers ◽  
Type Iii ◽  
Insertional Inactivation

ABSTRACT Aeromonas hydrophila is a gram-negative opportunistic pathogen in fish and humans. Many bacterial pathogens of animals and plants have been shown to inject anti-host virulence determinants into the hosts via a type III secretion system (TTSS). Degenerate primers based on lcrD family genes that are present in every known TTSS allowed us to locate the TTSS gene cluster in A. hydrophila AH-1. A series of genome walking steps helped in the identification of 25 open reading frames that encode proteins homologous to those in TTSSs in other bacteria. PCR-based analysis showed the presence of lcrD homologs (ascV) in all of the 33 strains of A. hydrophila isolated from various sources. Insertional inactivation of two of the TTSS genes (aopB and aopD) led to decreased cytotoxicity in carp epithelial cells, increased phagocytosis, and reduced virulence in blue gourami. These results show that a TTSS is required for A. hydrophila pathogenesis. This is the first report of sequencing and characterization of TTSS gene clusters from A. hydrophila. The TTSS identified here may help in developing suitable vaccines as well as in further understanding of the pathogenesis of A. hydrophila.

Biophysical Characterization of the Type III Secretion System Translocator Proteins and the Translocator Proteins Attached to Bacterium-Like Particles

2015 ◽  
Vol 104 (12) ◽  
pp. 4065-4073 ◽  
Author(s):  
Xiaotong Chen ◽  
Shyamal P. Choudhari ◽  
Prashant Kumar ◽  
Ronald T. Toth ◽  
Jae Hyun Kim ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Biophysical Characterization ◽  
Type Iii
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