Autor(es):
Sousa, Ana Margarida
; Nicolau, Ana
; Lourenço, Anália
; Pereira, M. O.
Data: 2012
Identificador Persistente: http://hdl.handle.net/1822/28781
Origem: RepositóriUM - Universidade do Minho
Descrição
Colony morphology changes may be an indicator of the phenotypic variations associated to
the pathogenecity, virulence and antimicrobial resistance of infection-causing
microorganisms. Particularly, phenotypic changes derived from biofilm growth and in
response to environmental stressors. For instance, in patients with cystic fibrosis, P.
aeruginosa colony morphology undergoes a conversion from non- to mucoid form
augmenting bacteria resistance to antibiotics considerably. However, the specific correlation
between some colony traits and the biological impact is unknown.
This study was thus designed to inspect the colony associated phenotypic alterations,
particularly the putative virulence determinants of biofilm-colonies, via morphological
observation and whole cell MALDI MS proteomics. The annotation of colony morphology
features was supported by a novel, in-house developed ontology, named colony morphology
ontology (CMO), and annotations are available at the MorphoColDB framework [1]. The
considerable diversity of the morphotypes observed within and across species, with diferente
biofilm-forming abilities and susceptibilities [2], led to the application of this method in support
of the identification of virulent morphotypes as primary therapeutic candidates. Further
results on the protein expression of P. aeruginosa and S. aureus colonies confirmed
important differences between intra-species morphotypes and has promoted investigation of
the role of stress-regulated proteins.
Although preliminary, these results confirm the potential of using a combination of
highthroughput screening of pathogenic bacteria proteome with susceptibility tests and
expert inputs to reach a comprehensive understanding of the persistence and antimicrobial
resistance of pathogenic bacteria, as well as to design new therapeutic strategies.