Vol. 4, Issue 9 (2018)
Weak association of Staphylococcus aureus hemolytic activity with reduced FEV1 in older children with cystic fibrosis
Author(s): Ying Liu, Lu Ji, Junshu Yang, Dengke Zhong, Jiang Zhang, Mark Wylam, James Phillips, Yinduo Ji
Abstract: This study aimed to determine the role of staphylococcal hemolytic activity in the pathogenesis of cystic fibrosis (CF) lung disease. We collected 50 Staphylococcus aureus isolates and pulmonary function data from CF patients. The hemolytic activities of these isolates and lung functions were analyzed. In addition variation in the hla promoter region of these isolates was determined following PCR amplification and sequencing. Wide ranges of hemolytic activities were observed in these isolates. A weak negative correlation between the hemolytic activities and the FEV1 percent predicted was shown in CF patients greater than ten years old. Moreover, we found a significant difference in the FEV1 percent predicted and FEV1/FVC ratio in S. aureus CF patients older than 10 years of age compared to those less than 10 years of age, suggesting a greater burden of obstructive lung disease in the older group. DNA alignment analysis on the DNA sequences revealed eight single nucleotide polymorphisms (SNPs) within the hla promoter region, which did not correlate with hemolytic activity. Our results suggest that higher levels of hemolytic activity may contribute to the pathogenesis of CF, resulting in lung function deterioration. However, SNPs in different locations of hla promoter regions do not direct hemolytic activity.