ANALYSIS OF THE MUTS-RPOS CHROMOSOMAL REGION IN PSEUDOMONAS AERUGINOSA

LUJAN, ADELA M; ARGARAÑA CARLOS E; SMANIA ANDREA MARIA

Rosario Santa Fe, Argentina

Congreso; XLII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2006

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

In enterobacteria genomes, mutS and rpoS, encoding one of themain components of DNA mismatch repair and the alternativestationary-phase σS factor respectively, are located in a highlypolymorphic region of the chromosome. The extensivepolymorphism of this region is postulated to result from cyclingbetween environments in which the functional or non-functionalmutS and rpoS genes provide distinct fitness advantages.Furthermore, in E. coli alterations in this region have beencorrelated with a mutS produced enhanced mutation/recombination rate and implicated in the emergence of newpathogenic clones. In spite of the importance of Pseudomonasaeruginosa as a human pathogen, there is no characterization ofthis segment in this versatile bacterium. By PCR amplificationand restriction fragment length polymorphism (RFLP) we firstanalyze the extent and nature of the mutS-rpoS intergenic regionin sixteen different P. aeruginosa Cystic Fibrosis isolates as wellas in the PAO1 and the soil isolated Hex1T strains. Interestingly,we observed that the length of that region was equivalent in allthe strains analyzed, which in addition to the RFLP analysissuggest it would be unexpectedly conserved. Further studies arebeing carried out in order to analyze the structure of this region inP. aeruginosa and the consequences associated with mutSmutations and loss of DNA mismatch repair.