eCite Digital Repository

Lateral flagella and swarming motility in Aeromonas species


Kirov, SM and Tassell, BC and Semmler, A and O'Donovan, LA and Rabaan, AA and Shaw, JG, Lateral flagella and swarming motility in Aeromonas species, Journal of Bacteriology, 184, (2) pp. 547-555. ISSN 0021-9193 (2002) [Refereed Article]

DOI: doi:10.1128/JB.184.2.547-555.2002


Swarming motility, a flagellum-dependent behavior that allows bacteria to move over solid surfaces, has been implicated in biofilm formation and bacterial virulence. In this study, light and electron microscopic analyses and genetic and functional investigations have shown that at least 50% of Aeromonas isolates from the species most commonly associated with diarrheal illness produce lateral flagella which mediate swarming motility. Aeromonas lateral flagella were optimally produced when bacteria were grown on solid medium for ≈ 8 h. Transmission and thin-section electron microscopy confirmed that these flagella do not possess a sheath structure. Southern analysis of Aeromonas reference strains and strains of mesophilic species (n = 84, varied sources and geographic regions) with a probe designed to detect lateral flagellin genes (lafA1 and lafA2) showed there was no marked species association of laf distribution. Approximately 50% of these strains hybridized strongly with the probe, in good agreement with the expression studies. We established a reproducible swarming assay (0.5% Eiken agar in Difco broth, 30°C) for Aeromonas spp. The laf-positive strains exhibited vigorous swarming motility, whereas laf-negative strains grew but showed no movement from the inoculation site. Light and scanning electron microscopic investigations revealed that lateral flagella formed bacteriumbacterium linkages on the agar surface. Strains of an Aeromonas caviae isolate in which lateral flagellum expression was abrogated by specific mutations in flagellar genes did not swarm, proving conclusively that lateral flagella are required for the surface movement. Whether lateral flagella and swarming motility contribute to Aeromonas intestinal colonization and virulence remains to be determined.

Item Details

Item Type:Refereed Article
Research Division:Biomedical and Clinical Sciences
Research Group:Medical microbiology
Research Field:Medical bacteriology
Objective Division:Health
Objective Group:Clinical health
Objective Field:Clinical health not elsewhere classified
UTAS Author:Kirov, SM (Associate Professor Sylvia Kirov)
UTAS Author:Tassell, BC (Miss Bronwen Tassell)
UTAS Author:Semmler, A (Ms Annalese Semmler)
UTAS Author:O'Donovan, LA (Ms Lisa O'Donovan)
ID Code:26041
Year Published:2002
Web of Science® Times Cited:105
Deposited By:Pathology
Deposited On:2002-08-01
Last Modified:2004-08-13

Repository Staff Only: item control page