Acinetobacter baumannii é um patógeno oportunista, geralmente resistente a muitos antimicrobianos, que causa surtos de infecções hospitalares. Assim, a sua habilidade de formar biofilme pode explicar a capacidade de sobreviver no ambiente hospitalar e em utensílios médicos. O objetivo desse estudo foi avaliar a capacidade de duas cepas clínicas de A. baumannii obtido de hospitais de Porto Alegre, Brasil (abC e abH) e uma cepa controle ATCC 19606 (abA) formar biofilme e realizar a análise transcricional dos genes possivelmente envolvidos na produção e manutenção do biofilme: bap, abaI, ompA, bfmRS, csuAB, pgaA, pilZ, wspR, eal, eagg, IscRSU e csdA. A capacidade de formação de biofilme foi avaliada pelo método cristal violeta em superfície plástica a 25°C e 37°C nos meios LB, LB + 1% glicose, urina pura e LB + 10% sangue de carneiro. A análise transcricional foi feita por real time PCR. A cepas AbH, AbC e AbA foram fortes formadoras de biofileme em LB e LB+glicose à 25 e 37°C. Em LB+sangue, as cepas AbH e AbA foram fortes formadoras e AbC foi fraca formadora de biofilme. Em urina, a cepa AbH foi moderadamente formadora, AbC e AbA foram fracas formadoras de biofilme. Os genes wspR, pgaA, ompA, bap, abaI de AbA, csdA de AbH e o operon IscRSU foram superexpressos em biofilme; os genes eagg de AbH, pilZ e csuAB foram inibidos e os genes bfmRS, eal, eagg de AbA, csdA de AbA e abaI de AbH não possuíram uma variação significativa na expressão durante o biofilme. Portantanto, a regulação positiva dos genes wspR, pgaA, ompA, bap, csdA e do operon IscRSU é um indício de sua importância na formação e manutenção do biofilme por esse patógeno. / Acinetobacter baumannii is an opportunistic pathogen which causes a wide range of nosocomial infections, being usually multirresistent to drugs. Their ability to form biofilm can explain the feature of surviving inside hospital environment and on medical devices. The aim of the present study was to evaluate the ability of two clinically isolated MDR A. baumannii strain, obtained from a general hospital of Porto Alegre, RS, Brazil (AbH and AbC), and the reference ATCC 19606 strain (AbA), to form biofilm and to analyze the relative expression of genes putatively involved in biofilm formation: bap, abaI, ompA, bfmRS, csuAB, pgaA, pilZ, wspR, eal, eagg, IscRSU e csdA. The biofilm formation capability was evaluated by the crystal-violet staining method on plastic surfaces at 25°C and 37°C using the broth LB, LB + 1% glucose, pure urine and LB + 10% sheep blood. The trancritional profiling of the genes was analyzed through real time PCR methodologies. The strains AbH, AbC e AbA were strong biofilm producers in LB e LB+glucose at 25 and 37°C. In the broth LB+blood, the strains AbH and AbA were strong biofilm producers and AbC was week biofilm producer. In urine, the strain AbH was moderated producer, AbC and AbA were week biofilm producers. The genes wspR, pgaA, ompA, bap, abaI from AbA, csdA from AbH and the operon IscRSU were overexpressed in biofilm; the genes eagg de AbH, pilZ e csuAB were suppressed and the genes bfmRS, eal, eagg from AbA, csdA from AbA e abaI from AbH did not vary their expression significantly during the biofilm condition. In conclusion, the factors wspR, pgaA, ompA, bap, csdA and of the operon IscRSU, that were positively regulated, appear to have an important role during the process of biofilm formation by A. baumannii.
| Identifer | oai:union.ndltd.org:IBICT/oai:www.lume.ufrgs.br:10183/72039 |
| Date | January 2012 |
| Creators | Bierhals, Christine Garcia |
| Contributors | Frazzon, Ana Paula Guedes, Frazzon, Jeverson |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, instname:Universidade Federal do Rio Grande do Sul, instacron:UFRGS |
| Rights | info:eu-repo/semantics/openAccess |
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