Immunogenic response of IgY polyclonal antibody 35 kDa outer membrane protein (OMP) adherence protein of Proteus mirabilis

Background: Pseudomonas aeruginosa is an important cause f severe infections in immuno-compromised patients. It has been ommonly associated to repeated bronchial infections in patients ith CF and nosocomial infections. Its pathogenic ability derives rom the presence of several cell-associated and secreted virulence actors. Various genomic islands (PAPI-1, PAPI-2, PAGI-1, PAGI-2, AGI-3, PAGI-4, and pKLC102) have been characterized in differnt P. aeruginosa strains from diverse habitats and geographical ocations. Methods: The aim of this study was to characterize phenotypially and genetically a set of 100 P. aeruginosa strains isolated from 5 unrelated patients with pneumonia hospitalized in an intensive are unit. To assess the occurrence of these genomic islands (GEIs) e built a chromosomalDNAmacroarrayof all P. aeruginosa strains nd it was then hybridized with labeled probes derived from speific genes according to each GEI. Additionally, PFGE patterns with peI, the frequency of virulence genes and susceptibility patterns f the strains were studied. Results:Our results showed that almost all strains presented up o eight virulence genes. Only two strains were pilA gene negative. he dendrogram based on PFGE patterns showed that our strains ased on >80% of homology identified among them presented 9 restriction patterns. The strains showed a variable number of slands or a different genes composition among them, besides of a pecific antimicrobial pattern indicating that each one of themwas n unrelated isolate. In terms of the number of genomic islands per train, 7 GEIs were found in 34% of the strains, 6 in 18%, 5 in 12%, in 14%, 3 in 10%, 2 in 7%, and 1 in 4%; only one isolate did not resent any GEIs. Conclusion: In conclusion our data show that theP. aerugiosastrains exhibited an epidemic population structure with high ecombination rate resulting in a high frequency of GEIs.