Inquilinus limosus isolated from a patient with chronic cystic fibrosis. First report in Mexico and evidence that co-infection with Pseudomonas aeruginosa promotes the accelerated and increased formation of extracellular neutrophil traps

Cystic fibrosis is characterized by abnormal mucous secretions in the lungs that favor the proliferation of colonizing bacteria, with Pseudomonas aeruginosa and Staphylococcus aureus being the most isolated, however, other less known species could also have an impact on the health of the patient. Here we demonstrate the isolation and antibiotic resistance profiles of Inquilinus limosus, a rarely reported multidrug resistant bacterium, and compare them to a co-infectant strain of Pseudomonas aeruginosa. Likewise, we found that co-infection with both bacteria promotes increased formation of neutrophil extracellular traps, which can have an impact on the disease severity and make treatment difficult.

A High Level of Soluble CD40L Is Associated with P. aeruginosa Infection in Patients with Cystic Fibrosis

Objective

The aim of this study was to evaluate whether the concentration of sCD40L, a product of platelet activation, correlates with the presence of Pseudomonas aeruginosa in the airway of patients with cystic fibrosis (CF) and to determine its possible clinical association.

Methods

Sixty patients with CF, ranging in age from 2 months to 36 years, were studied. The demographics, cystic fibrosis transmembrane conductance regulator (CFTR) genotype, spirometry measurements, radiographic and tomographic scans, platelet count in peripheral blood, sCD40L, IL-6, TNF-α and ICAM1 data were collected. Infection-colonization of the airway was evaluated using sputum and throat swab cultures; the levels of anti-Pseudomonas aeruginosa antibodies (Anti-PaAb) were evaluated.

Results

Patients with CF and chronic colonization had anti-PaAb values of 11.6 ± 2.1 ELISA units (EU) and sCD40L in plasma of 1530.9 ±1162.3 pg/mL; those with intermittent infection had 5.7 ± 2.7 EU and 2243.6 ± 1475.9 pg/mL; and those who were never infected had 3.46 ± 1.8 EU (p≤0.001) and 1008.1 ± 746.8 pg/mL (p≤0.01), respectively. The cutoff value of sCD40L of 1255 pg/mL was associated with an area under the ROC (receiver operating characteristic curve) of 0.84 (95% CI, 0.71 to 0.97), reflecting P. aeruginosa infection with a sensitivity of 73% and a specificity of 89%. Lung damage was determined using the Brasfield Score, the Bhalla Score, and spirometry (FVC%, FEV1%) and found to be significantly different among the groups (p≤0.001).

Conclusion

Circulating sCD40L levels are increased in patients with cystic fibrosis and P. aeruginosa infection. Soluble CD40L appears to reflect infection and provides a tool for monitoring the evolution of lung deterioration.

[Impact of eradication of Pseudomonas aeruginosa on survival in Mexican patients with cystic fibrosis]

INTRODUCTION

Patients with cystic fibrosis (CF) present lower airway infection with Pseudomonas aeruginosa. Treatment of initial infection is fundamental to reduce subsequent damage.

MATERIAL AND METHODS

We evaluated the efficacy of eradication treatment of P. aeruginosa in patients with CF from northeast Mexico using two protocols: inhaled colistin/oral ciprofloxacin and nebulized tobramycin 300 mg/oral ciprofloxacin. The intervention group included 17 patients with CF and recent infection with P. aeruginosa. The control group consisted of 23 chronically colonized patients of comparable age.

RESULTS

Patients received 27 courses of eradication treatment. P. aeruginosa was eradicated in 21/27 (77.77%). The infection free period was 16.9, 11.7 months (colistin) and 17 ± 9.7 months (tobramycin) with no statistically significant difference (P = 0.97).

CONCLUSIONS

Treated patients maintained normal lung function, better nutritional status, and a better chest X-ray score. In the control group 17/23 (73.9%) patients died with no deaths in the study group.