Table 1.
Pseudomonas Strain Information Provided by American Type Culture Collection.
Table 2.
Optical density of Pseudomonas cultures in various media measured at 24 h.
Table 3.
Pseudomonas toxin production.
Table 4.
Antibiotic susceptibility of Pseudomonas strains used in this study.
Table 5.
SIR Ranking of Pseudomonas strains used in this study.
Table 6.
SIR Ranking of Antibiotics used in this study.
Fig 1.
Cellular Viability During Pseudomonas Exposure.
HT29 cells were exposed to Pseudomonas strains for 24 h at 37°C. Bacteria were rinsed from the wells, and one mg mL-1 MTT was added. MTT formazan generated after two h incubation was solubilized with DMSO and quantified by absorbance at 505 nm with a multiwell spectrophotometer. Data represent the mean bioreduction activities of three wells ± standard deviation compared to saline-treated wells. Asterisks indicate statistically different values compared to control exposures as determined using ANOVA and Dunnett’s Multiple Comparison Test (p < 0.05).
Fig 2.
Pulmonary Clearance of Pseudomonas Strains.
At various times following endotracheal exposure of 106 cfu per mouse of each Pseudomonas strain, the lungs of mice were harvested, homogenized and serially diluted in physiological saline. Dilutions were spread-plated onto nutrient broth and bacteria were enumerated 18 h later. The red markers represent the mean colony count; blue markers represent counts from each mouse. Black arrows point to noteworthy features described in the Results section.
Fig 3.
Pulmonary Cytokine Levels During Pseudomonas Exposure.
Balb/c mice were endotracheally instilled with saline or 106 cfu of each Pseudomonas strain. At various times following exposure, animals were euthanized and lungs were harvested. Following tissue homogenization, cytokine levels were measured using a multiplex bead array system. Data points represent the mean of three or four treated mice. Asterisks indicate statistically different values compared to saline exposures, as determined using ANOVA and Dunnett’s Multiple Comparison Test (p < 0.05). Bacteria with significant differences are indicated with red boxes in the graph legends.
Fig 4.
Pulmonary Granulocyte Infiltration during Pseudomonas Exposure.
Balb/c mice were endotracheally instilled with saline or 106 cfu of each Pseudomonas strain. At various times following exposure, animals were euthanized and lungs were harvested. Lungs were sectioned and stained with fluorescently tagged Ly6G antibody (inset shows example micrographs). Numbers of positively stained cells (red) were enumerated from nine micrograph fields (three fields from three mice for each treatment) and expressed as fold-change compared to those from saline-exposed mice. Asterisks indicate statistically different values compared to saline exposures, as determined using ANOVA and Dunnett’s Multiple Comparison Test (p < 0.05). Bacteria with significant differences of at least 2-fold are indicated with red boxes in the graph legends.
Fig 5.
Serum Amyloid A during Pseudomonas Exposure.
Balb/c mice were endotracheally instilled with saline or 106 cfu of each Pseudomonas strain. At various times following exposure, blood was collected by cardiac puncture. Blood was processed for SAA detection by ELISA. Data is expressed as the fold-change compared to control values ± relative error (n = 3). For Pa31480 treatment at 48 h, the SAA values for each mouse are indicated by T1, T2, and T3. The variation in these values explains the large relative error observed. Asterisks indicate statistically different values compared to saline exposures, as determined using ANOVA and Dunnett’s Multiple Comparison Test (p < 0.05). Bacteria with significant differences are indicated with red boxes in the graph legends.
Table 7.
Summary of Assays for Comparing Potential Virulence Characteristics of Pseudomonas.