Role of coaggregation in the pathogenicity and prolonged colonisation of Vibrio cholerae

AbstractCholera is an acute diarrheal illness caused by the Gram-negative bacteriumVibrio cholerae. The pathogen is known for its ability to form biofilm that confers protection against harsh environmental condition and as part of the colonisation process during infection. Coaggregation is a process that facilitates the formation of biofilm. In a preliminary in vitro study, high coaggregation index and biofilm production were found betweenV. cholerae with human commensals namelyEscherichia coli andEnterobacter cloacae. Building upon these results, the effects of coaggregation were further evaluated using adult BALB/c mouse model. The animal study showed no significant differences in mortality and fluid accumulation ratio between treatment groups infected withV. cholerae alone and those infected with coaggregation partnership (V. cholerae withE. coli orV. cholerae withE. cloacae). However, mild inflammation was detected in both partnering pairs. Higher density ofV. cholerae was recovered from faecal samples of mice co-infected withE. coli andV. cholerae in comparison with other groups at 24  h post-infection. This partnership also elicited slightly higher levels of interleukin-5 (IL-5) and interleukin-10 (IL-10). Nonetheless, the involvement of autoinducer-2 (AI-2) as the signalling molecules in quorum sensing system is not evident in this study. SinceE. coli is one of the common commensals, our result may suggest the involvement of commensals in cholera development.
Source: Medical Microbiology and Immunology - Category: Microbiology Source Type: research