TY - JOUR
T1 - Structural and regulatory mutations in Vibrio parahaemolyticus type III secretion systems display variable effects on virulence
AU - Calder, Thomas
AU - de Souza Santos, Marcela
AU - Attah, Victoria
AU - Klimko, John
AU - Fernandez, Jessie
AU - Salomon, Dor
AU - Krachler, Anne Marie
AU - Orth, Kim
N1 - Publisher Copyright:
© 2014 Federation of European Microbiological Societies.
PY - 2014/12/1
Y1 - 2014/12/1
N2 - The Gram-negative bacterium, Vibrio parahaemolyticus, is a major cause of seafood-derived food poisoning throughout the world. The pathogenicity of V. parahaemolyticus is attributed to several virulence factors, including two type III secretion systems (T3SS), T3SS1 and T3SS2. Herein, we compare the virulence of V. parahaemolyticus POR strains, which harbor a mutation in the T3SS needle apparatus of either system, to V. parahaemolyticus CAB strains, which harbor mutations in positive transcriptional regulators of either system. These strains are derived from the clinical RIMD 2210633 strain. We demonstrate that each mutation affects the virulence of the bacterium in a different manner. POR and CAB strains exhibited similar levels of swarming motility and T3SS effector production and secretion, but the CAB3 and CAB4 strains, which harbor a mutation in the T3SS2 master regulator gene, formed reduced biofilm growth under T3SS2 inducing conditions. Additionally, while the cytotoxicity of the POR and CAB strains was similar, the CAB2 (T3SS1 regulatory mutant) strain was strikingly more invasive than the comparable POR2 (T3SS1 structural mutant) strain. In summary, creating structural or regulatory mutations in either T3SS1 or T3SS2 causes differential downstream effects on other virulence systems. Understanding the biological differences of strains created from a clinical isolate is critical for interpreting and understanding the pathogenic nature of V. parahaemolyticus.
AB - The Gram-negative bacterium, Vibrio parahaemolyticus, is a major cause of seafood-derived food poisoning throughout the world. The pathogenicity of V. parahaemolyticus is attributed to several virulence factors, including two type III secretion systems (T3SS), T3SS1 and T3SS2. Herein, we compare the virulence of V. parahaemolyticus POR strains, which harbor a mutation in the T3SS needle apparatus of either system, to V. parahaemolyticus CAB strains, which harbor mutations in positive transcriptional regulators of either system. These strains are derived from the clinical RIMD 2210633 strain. We demonstrate that each mutation affects the virulence of the bacterium in a different manner. POR and CAB strains exhibited similar levels of swarming motility and T3SS effector production and secretion, but the CAB3 and CAB4 strains, which harbor a mutation in the T3SS2 master regulator gene, formed reduced biofilm growth under T3SS2 inducing conditions. Additionally, while the cytotoxicity of the POR and CAB strains was similar, the CAB2 (T3SS1 regulatory mutant) strain was strikingly more invasive than the comparable POR2 (T3SS1 structural mutant) strain. In summary, creating structural or regulatory mutations in either T3SS1 or T3SS2 causes differential downstream effects on other virulence systems. Understanding the biological differences of strains created from a clinical isolate is critical for interpreting and understanding the pathogenic nature of V. parahaemolyticus.
KW - Bacterial virulence
KW - Biofilm
KW - Invasion
KW - T3SS
KW - Vibrio parahaemolyticus
UR - http://www.scopus.com/inward/record.url?scp=84919691412&partnerID=8YFLogxK
U2 - 10.1111/1574-6968.12619
DO - 10.1111/1574-6968.12619
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AN - SCOPUS:84919691412
SN - 0378-1097
VL - 361
SP - 107
EP - 114
JO - FEMS Microbiology Letters
JF - FEMS Microbiology Letters
IS - 2
ER -