Production of elastase, exotoxin A, and alkaline protease in sputa during pulmonary exacerbation of cystic fibrosis in patients chronically infected by Pseudomonas aeruginosa

Abstract

Secretion of Pseudomonas aeruginosa elastase, exotoxin A, and alkaline protease in sputum during bronchopulmonary exacerbations was examined in 18 cystic fibrosis patients chronically infected with this microorganism. The patients were studied during one or several exacerbation periods necessitating hospitalizations of 12 to 20 days. In all cases, P. aeruginosa was present in bronchial secretions at admission and was not eradicated after treatment. The P. aeruginosa density decreased significantly after antibiotic therapy but remained greater than 10 6 CFU/g of sputum in most cases. Significant amounts of P. aeruginosa exoproteins were measured in total homogenized bronchial secretions by immunoenzymatic assays. The detection of higher levels of exoproteins at admission, the significant decrease after treament, and the absence of exoproteins during intercrisis phases constituted arguments for a renewal of virulence of P. aeruginosa during exacerbations. Nevertheless, the concomitant changes in bacteria load and the triggering of the inflammatory process and immune complex formation could also contribute to pulmonary exacerbations.

Reliable Enzyme‐Linked Immunosorbent Assay Systems for Pathogenic Factors of Pseudomonas aeruginosa Alkaline Proteinase, Elastase, and Exotoxin A: A Comparison of Methods for Labeling Detection Antibodies with Horseradish Peroxidase

“…The analytical detection limits for our alkaline proteinase, elastase, and exotoxin A ELISA systems were 18 pg/ml, 34 pg/ml, and 22 pg/ml, respectively; these values are lower than those for the ELISAs described by Jaffar-Bandjee et al (16,18) systems is only one-tenth of that used in the previously described systems. The working range of each of our ELISA systems is 0-100 ng/ml, which is 5 times wider than that of the ELISA systems described by Jaffar-Bandjee et al (16,18) (0-20 ng/ml) and 25 times wider than that of the exotoxin A ELISA system described by Ogaard et al (27) (0-4 ng/ml). The single most important advantage of our ELISA systems is the linearity of the standard curves within the range of 0-100 ng/ml; this facilitates easier analysis in every respect.…”

“…Of the 2 labeling methods compared, the maleimide-pyridyl disulfide method exhibited higher sensitivity. For the preparation of IgG-HRP conjugates, Jin et al (20), Jaffar-Bandjee et al (16)(17)(18), and Schultz et al (32) used the periodate method (34). In the periodate method, the carbohydrate shell of HRP is oxidized at pH 4-5.…”

Predicting antibiotic-associated virulence ofPseudomonas aeruginosausing anex-vivolung biofilm model

“…Production of proteases is triggered by the quorum sensing system to degrade vital host proteins and antibodies. In CF lungs, proteases have been shown to cause a severe inflammatory response leading to pulmonary damage [24], and were detected in sputum during exacerbation [25]. Pyocyanin is also regulated by the quorum sensing system.…”

Testing the neutral theory of biodiversity with the microbiome dataset from cystic fibrosis patients

“…[10][11][12][13] In previous studies, it has been found that the microbial community of lung could be changed due to alerted microenvironment of lung, which may result from diseases or external environmental disturbance. [4,[14][15][16][17][18][19][20][21][22][23] In the case of CF, mutations in CFTR can change the ion flux, impact the normal airway function, and compromise the normal innate immune defense finally, making the lower airways easier to be infected. Although typically only a few species are associated with chronic airway infections in CF, along with the improved treatments of infections, new species associated with CF has emerged, and the total microbes should be took into account as a whole.…”