Papel dos flagelos polar e lateral em cepas de Aeromonas caviae na formação de biofilme e aderência celular

• Autor(a) principal: Santos, Paula Gomes dos
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/14416
• topic: Aeromonas caviae; Biofilm; Flagella; Adherence; Aeromonas cavie; Biofilme; Flagelos; Aderência; CNPQ::CIENCIAS BIOLOGICAS::MICROBIOLOGIA

Aeromonas spp. are bacteria Gram-negative able to cause intestinal and extraintestinal diseases. The virulence of some species of this genus has already been associated to several aspects, such as the expression of flagellum and following bacterium mobility. Aeromonas caviae presents two distinct flagellar systems, one of which is responsible for mobility in liquid environments (swimming) at where the polar flagellum is involved, and the other is associated to sliding in solid or viscous surfaces (swarming), in which lateral flagella take part. In order to evaluate the contribution of both flagella in the biofilm formation in plastic surfaces and its adherence to cell line HEp-2, 76 strains of isolated A. caviae from distinct sources were analyzed. The results from our studies showed that detection of gene flaA (polar flagellin) was more frequent (94%) than gene lafA (lateral flagellin) (71%), and apparently, the presence of the last one seems to be conditioned to the first one (the gene flaA). All the strains that presented the genotype flaA-lafA- were unable to form biofilm, such as 76% of strains flaA+lafA-. The aquatic strains were those who showed lesser percentage of positivity for the lateral flagellin gene (57%), and higher incapacity of biofilm formation (71%). Moreover, 95% of the flaA+lafA+ strains formed biofilm, and all strains that quantitatively showed a strong biofilm, contained both genes. The adherence to HEp-2 proved to be efficient in all cases where at least one of the two flagella was present at, and in two cases where both were absent, with prevalence of the aggregative pattern. However, an exclusive interference from the lateral flagella was not perceived in this process. All of the three strains that did not adhere to the cell model used, or that adhered in a very discrete way, did not show neither gene flaA nor gene lafA. In conclusion, we suggest that the complete function of both flagella usually is a requirement in the adherence processes to biotic and abiotic surfaces. However, additional studies on the contribution of these structures in the pathogenesis of A. caviae need to be carried out.