Comparison of neutrophil apoptosis by the pseudomonas aeruginosa exotoxins between healthy individuals and term infants

ABSTRACT

Pseudomonas aeruginosa may be colonized in different human tissues and result in some infections potentially. Thus, considering that these bacteria are resistance to most of the current antibiotics, an examination on pathogenesis mechanisms of such bacteria can be effective in controlling the infections developed by it. In this project, among 40 blood samples [20 healthy persons, 20 infants], an amount of 5 ml [2 ml in the infants] heparinized blood was collected from each and then neutrophils were isolated by a standard method and were counted by neubauer lam. After culturing Pseudomonas bacteria in broth medium, some tubes with densities of 1, 2, 3 and 4 McFarland were prepared and the bacteria were isolated by centrifuge method with 3000rpm for 10 minutes and then its exotoxin were exposed to neutrophils of the groups under study. The effect of time and the bacteria count on the amount of the secreted toxin and in adjacency to neutrophils was measured. There were 11 men and 9 women in the health group and the infants group consisted of 12 boys and 8 girls. Death cell percentage of neutrophils was 100% in the health group and 8.90% in the infants group. Percentage of bacterial growth in the medium 1 and 2 McFarland was zero; in the medium 3 McFarland, it was 12.5% in the healthy group and 1% in the infants group [p<0.10]. The average rate of cell death in the minute 15th was different in two groups [68.5% in health group vs. 92.5% in the infants] [p<0.0005]. This study showed the effect of Pseudomonas bacteria on the development of early cell death in the infants very well. As it was shown, this effect is time-dependent and this cell death [apoptosis] is occurred in the infants earlier than health people