J Osayande. Easy Identification of Difficult-to-Type Pseudomonas aeruginosa Clinical and Environmental Isolates. The Internet Journal of Microbiology. 2008 Volume 7 Number 2.
Several genes have been employed as taxonomic markers for the positive identification of
Clinically, this organism plays a significant role in the survival rates of affected patients; however, this role becomes increasingly important when the organism is detected earlier and specifically identified.
Biochemical methods have, to a certain extent, facilitated the identification of
Much would be gained by an immuno-deficient patient who suffers from a burn wound, cancer, or cystic fibrosis and was infected by this organism if the pathogen could be detected in time, as prompt isolation and identification of this organism and other Gram-negative pathogens are often needed for patients to meet clinical trial entrance criteria (Qin
M-PCR was performed using
1-4: Degenerate primers were designed following a Clustal X alignment of all type-II
5-12: Multiplex PCR primers for the identification of
13-16: Primers for the amplification of
Some of the strains above were previously identified as
Figure 1. Multiplex PCR (M-PCR) amplification of the three
These isolates were negative for this primer set; however, they tested positive for primer set 3 and 4 (see Figure 6).
Amplification of the ferripyoverdine receptor genes in the ‘difficult-to-type’
Following the alignment of sequences of those strains that were 99-100% identical at the nucleotide level to the ferripyoverdine receptor sequences of other type-II pyoverdine-producing reference
Figure 7. Homology tree constructed using the DNAMAN software shows relatedness of the
It has been hypothesized that ferripyoverdine receptors are targeted by antibiotics and bacteriophages and serve as entry points (Wayne and Neilands, 1975; Guerinot, 1994; Andrews
It would be interesting to study various aspects of these organisms, but this may be difficult because of the phenotypic (and/or genotypic) variations that exist within these bacterial species (Reid and Kirov, 2004; Zeng and Kim, 2004). Knowledge of the pyoverdine region, including the complete
I am grateful to Vrije Universiteit Brussels (VUB) for the provision of Academic Scholarship.