Heterogeneous production of proteases from Brazilian clinical isolates of Pseudomonas aeruginosa.
Enferm Infecc Microbiol Clin
; 35(10): 630-637, 2017 Dec.
Article
em En, Es
| MEDLINE
| ID: mdl-27480954
ABSTRACT
BACKGROUND:
Pseudomonas aeruginosa is an important human pathogen that causes severe infections in a wide range of immunosuppressed patients. Herein, we evaluated the proteolytic profiles of 96 Brazilian clinical isolates of P. aeruginosa recovered from diverse anatomical sites.METHODS:
Cell-associated and extracellular proteases were evidenced by gelatin-SDS-PAGE and by the cleavage of soluble gelatin. Elastase was measured by using the peptide substrate N-succinyl-Ala-Ala-Ala-p-nitroanilide. The prevalence of elastase genes (lasA and lasB) was evaluated by PCR.RESULTS:
Bacterial extracts were initially applied on gelatin-SDS-PAGE and the results revealed four distinct zymographic profiles as follows profile I (composed by bands of 145, 118 and 50kDa), profile II (118 and 50kDa), profile III (145kDa) and profile IV (118kDa). All the proteolytic enzymes were inhibited by EDTA, identifying them as metalloproteases. The profile I was the most detected in both cellular (79.2%) and extracellular (84.4%) extracts. Overall, gelatinase and elastase activities measured in the spent culture media were significantly higher (around 2-fold) compared to the cellular extracts and the production level varied according to the site of bacterial isolation. For instance, tracheal secretion isolates produced elevated amount of gelatinase and elastase measured in both cellular and extracellular extracts. The prevalence of elastase genes revealed that 100% isolates were lasB-positive and 85.42% lasA-positive. Some positive/negative correlations were showed concerning the production of gelatinase, elastase, isolation site and antimicrobial susceptibility.CONCLUSION:
The protease production was highly heterogeneous in Brazilian clinical isolates of P. aeruginosa, which corroborates the genomic/metabolic versatility of this pathogen.Palavras-chave
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Pseudomonas aeruginosa
/
Infecções por Pseudomonas
/
Proteínas de Bactérias
/
Metaloproteases
Tipo de estudo:
Clinical_trials
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Humans
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
/
Es
Revista:
Enferm Infecc Microbiol Clin
Assunto da revista:
DOENCAS TRANSMISSIVEIS
/
MICROBIOLOGIA
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Brasil