Identification and characterization of four potential virulence determinants of Aeromonas hydrophila

Abstract

Aeromonas hydrophila is a ubiquitous inhabitant of aqueous environments and an important pathogen of animals including humans. Two twitching motility proteins (PilT and PilU), a histone like protein (HU), and a flagella export and assembly protein (FlhA) were identified, sequenced and characterized as potential virulence factors. The results showed that pilT and pilU mutants did not affect the expression of pili in A. hydrophila. The viability of a HU mutant was severely reduced when the bacteria were subjected to heat shock treatment at 48 and 50 A?C. Inactivation of HU did not affect the susceptibility of the mutant to eight antibiotics and SDS. A defined insertion mutant in flhA resulted in the complete loss of polar flagella, and drastic reduction in swimming motility and biofilm formation. The present study is an attempt to identify additional virulent genes to understand the pathogenesis of A. hydrophila. FlhA shows as a promising candidate for further study.