[Etiological factors of vascular grafts infections and their resistance to antibiotics].

THE AIM

of our study was the identification of microorganisms causing vascular graft infections and the evaluation of their antimicrobial susceptibility.

MATERIAL AND METHODS

25 patients with infected vascular graft, took part in our research. In 19 patients late type of infection was recognized, in 6 the infection was qualified as early. Purulent discharge obtained from the fistula was inoculated on the bacteriological media. Antimicrobial susceptibility was assessed by disc-diffusion method.

RESULTS

Staphylococcus aureus and Pseudomonas aeruginosa proved to be the most frequently isolated microorganisms. Mixed infection, caused by two distinct bacteria, occurred in 5 patients; in all cases one species belonged to Gram-positive, and the second one to Gram-negative bacteria. In 50% of patients with early type infection different species of Gram-negative rods were present, in 37,5% of them S. aureus and S. epidermidis were isolated. In late type infection Gram-negative rods were isolated from 54,5% of patients and Gram-positive bacteria from 31,5% of patients. The most frequently isolated species appeared to be Pseudomonas aeruginosa. The isolated species of bacteria varied depending on the degree of infection (according to Shilagy and Samson).

CONCLUSIONS

A diversity of isolated species, the presence of mixed infections and resistance patterns typical for hospital flora among bacteria infecting vascular grafts cause that antibiotic therapy should always be based on the results of microbiological examination.